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  • 1.
    Albrektsson, Tomas
    et al.
    Malmö högskola, Odontologiska fakulteten (OD).
    Brunski, John
    Wennerberg, Ann
    Malmö högskola, Odontologiska fakulteten (OD).
    "A requiem for the periodontal ligament" revisited. Invited commentary2009Ingår i: International Journal of Prosthodontics, ISSN 0893-2174, E-ISSN 1139-9791, Vol. 22, nr 2, s. 120-122Artikel i tidskrift (Refereegranskat)
  • 2.
    Albrektsson, Tomas
    et al.
    Malmö högskola, Odontologiska fakulteten (OD).
    Chrcanovic, Bruno
    Malmö högskola, Odontologiska fakulteten (OD).
    Jacobsson, Magnus
    Malmö högskola, Odontologiska fakulteten (OD).
    Wennerberg, Ann
    Malmö högskola, Odontologiska fakulteten (OD).
    Osseointegration of Implants: A Biological and Clinical Overview2017Ingår i: JSM Dental Surgery, ISSN 2573-1548, Vol. 2, nr 3Artikel, forskningsöversikt (Refereegranskat)
    Abstract [en]

    Osseointegration was discovered in 1962 and coined as a term in 1977. Original definitions implied direct contact between foreign materials and bone without any interposed soft tissue layers. Today, osseointegration is regarded to be a foreign body response to separate foreign elements from bone. A new definition of the term is suggested in this paper; “Osseointegration is a foreign body reaction where interfacial bone is formed as a defense reaction to shield off the implant from the tissues”. Excellent clinical results of osseointegrated implants have been reported from dentistry and Ear Nose Throat surgery, the latter with the indications of a stable anchorage of hearing aids or facial epistheses in cases of facial trauma. In Orthopaedic surgery a randomized controlled clinical trial has been undertaken demonstrating very good clinical results supported by positive radiostereo-photogrammetical data.

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  • 3.
    Albrektsson, Tomas
    et al.
    Malmö universitet, Odontologiska fakulteten (OD). Malmö universitet, Biofilms Research Center for Biointerfaces. Department of Biomaterials, University of Gothenburg, Sweden.
    Chrcanovic, Bruno
    Malmö universitet, Odontologiska fakulteten (OD). Malmö universitet, Biofilms Research Center for Biointerfaces.
    Mölne, Johan
    Department of Pathology and Genetics, Sahlgrenska Academy, Sweden; University of Gothenburg, Sweden.
    Wennerberg, Ann
    Malmö universitet, Odontologiska fakulteten (OD). Malmö universitet, Biofilms Research Center for Biointerfaces. Department of Biomaterials, University of Gothenburg, Sweden.
    Foreign body reactions, marginal bone loss and allergies in relation to titanium implants2018Ingår i: European Journal of Oral Implantology, ISSN 1756-2406, E-ISSN 1756-2414, Vol. 11, nr Suppl 1, s. S37-S46Artikel, forskningsöversikt (Refereegranskat)
    Abstract [en]

    Aim: To describe general observations of immunological reactions to foreign materials and to realize that CP titanium gives rise to a foreign body reaction with subsequent bone embedment when placed as oral implants. To analyse the possibility of titanium allergy. Materials and methods: The present paper is of a narrative review type. Hand and Medline searches were performed to evaluate marginal bone loss of oral implants and the potential of titanium allergy. Results: Immunological reactions to foreign substances include Type I hypersensitivity reactions such as allergy, Type II hypersensitivity reactions characterised by IgM or IgG antibodies that may react with blood group antigens at transfusion, and Type III hypersensitivity caused by antigen-antibody immune complexes exemplified by acute serum sickness. There is also Type IV hypersensitivity, or delayed hypersensitivity, which is typically found in drug and foreign body reactions. It proved very difficult to find a universally acceptable definition of reasons for marginal bone loss around oral implants, which lead to most varying figures of so-called peri-implantitis being 1% to 2% in some 10-year follow-up papers to between 28% and 56% of all placed implants in other papers. It was recognised that bone resorption to oral as well as orthopaedic implants may be due to immunological reactions. Today, osseointegration is seen as an immune-modulated inflammatory process where the immune system is locally either up- or downregulated. Titanium implant allergy is a rare condition, if it exists. The authors found only two papers presenting strong evidence of allergy to CP titanium, but with the lack of universally accepted and tested patch tests, the precise diagnosis is difficult. Conclusions: CP titanium acts as a foreign body when placed in live tissues. There may be immunological reasons behind marginal bone loss. Titanium allergy may exist in rare cases, but there is a lack of properly designed and analysed patch tests at present.

  • 4.
    Albrektsson, Tomas
    et al.
    Malmö högskola, Odontologiska fakulteten (OD).
    Dahlin, Christer
    Jemt, Torsten
    Sennerby, Lars
    Turri, Alberto
    Wennerberg, Ann
    Malmö högskola, Odontologiska fakulteten (OD).
    Is Marginal Bone Loss around Oral Implants the Result of a Provoked Foreign Body Reaction?2014Ingår i: Clinical Implant Dentistry and Related Research, ISSN 1523-0899, E-ISSN 1708-8208, Vol. 16, nr 2, s. 155-165Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background When a foreign body is placed in bone or soft tissue, an inflammatory reaction inevitably develops. Hence, osseointegration is but a foreign body response to the implant, which according to classic pathology is a chronic inflammatory response and characterized by bone embedding/separation of the implant from the body. Purpose The aim of this paper is to suggest an alternative way of looking at the reason for marginal bone loss as a complication to treatment rather than a disease process. Materials and Methods The present paper is authored as a narrative review contribution. Results The implant-enveloping bone has sparse blood circulation and is lacking proper innervation in clear contrast to natural teeth that are anchored in bone by a periodontal ligament rich in blood vessels and nerves. Fortunately, a balanced, steady state situation of the inevitable foreign body response will be established for the great majority of implants, seen as maintained osseointegration with no or only very little marginal bone loss. Marginal bone resorption around the implant is the result of different tissue reactions coupled to the foreign body response and is not primarily related to biofilm-mediated infectious processes as in the pathogenesis of periodontitis around teeth. This means that initial marginal bone resorption around implants represents a reaction to treatment and is not at all a disease process. There is clear evidence that the initial foreign body response to the implant can be sustained and aggravated by various factors related to implant hardware, patient characteristics, surgical and/or prosthodontic mishaps, which may lead to significant marginal bone loss and possibly to implant failure. Admittedly, once severe marginal bone loss has developed, a secondary biofilm-mediated infection may follow as a complication to the already established bone loss. Conclusions The present authors regard researchers seeing marginal bone loss as a periodontitis-like disease to be on the wrong track; the onset of marginal bone loss around oral implants depends in reality on a dis-balanced foreign body response.

  • 5.
    Albrektsson, Tomas
    et al.
    Malmö universitet, Odontologiska fakulteten (OD). Malmö universitet, Biofilms Research Center for Biointerfaces. Univ Gothenburg, Dept Biomat, Gothenburg, Sweden.
    Dahlin, Christer
    NU Hosp Org, Dept Oral & Maxillofacial Surg ENT, Trollhattan, Sweden; Univ Gothenburg, Dept Biomat, Gothenburg, Sweden.
    Reinedahl, David
    Univ Gothenburg, Dept Prosthodont, Gothenburg, Sweden.
    Tengvall, Pentti
    Univ Gothenburg, Dept Biomat, Gothenburg, Sweden.
    Trindade, Ricardo
    Univ Gothenburg, Dept Prosthodont, Gothenburg, Sweden.
    Wennerberg, Ann
    Univ Gothenburg, Dept Prosthodont, Gothenburg, Sweden.
    An Imbalance of the Immune System Instead of a Disease Behind Marginal Bone Loss Around Oral Implants: Position Paper2020Ingår i: International Journal of Oral & Maxillofacial Implants, ISSN 0882-2786, E-ISSN 1942-4434, Vol. 35, nr 3, s. 495-502Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Purpose: The purpose of this paper is to present evidence that supports the notion that the primary reason behind marginal bone loss and implant failure is immune-based and that bacterial actions in the great majority of problematic cases are of a secondary nature. Materials and Methods: The paper is written as a narrative review. Results: Evidence is presented that commercially pure titanium is not biologically inert, but instead activates the innate immune system of the body. For its function, the clinical implant is dependent on an immune/inflammatory defense against bacteria. Biologic models such as ligature studies have incorrectly assumed that the primary response causing marginal bone loss is due to bacterial action. In reality, bacterial actions are secondary to an imbalance of the innate immune system caused by the combination of titanium implants and ligatures, ie, nonself. This immunologic imbalance may lead to marginal bone resorption even in the absence of bacteria. Conclusion: Marginal bone loss and imminent oral implant failure cannot be properly analyzed without a clear understanding of immunologically caused tissue responses.

  • 6.
    Albrektsson, Tomas
    et al.
    Malmö högskola, Odontologiska fakulteten (OD).
    Franke-Stenport, Victoria
    Wennerberg, Ann
    Malmö högskola, Odontologiska fakulteten (OD).
    Healing response2008Ingår i: Osseointegration: On Continuing Synergies in Surgery, Prosthodontics, and Biomaterials, Quintessence Publishing Co, Inc , 2008, s. 51-57Kapitel i bok, del av antologi (Övrigt vetenskapligt)
  • 7.
    Albrektsson, Tomas
    et al.
    Malmö universitet, Odontologiska fakulteten (OD). Department of Biomaterials, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
    Jemt, Torsten
    The Brånemark Clinic, Public Dental Health Service, Gothenburg, Sweden; Department of Prosthodontics, Institute of Odontology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
    Mölne, Johan
    Department of Pathology and Genetics, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
    Tengvall, Pentti
    Department of Biomaterials, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
    Wennerberg, Ann
    Department of Prosthodontics, Institute of Odontology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
    On inflammation-immunological balance theory-A critical apprehension of disease concepts around implants: Mucositis and marginal bone loss may represent normal conditions and not necessarily a state of disease2019Ingår i: Clinical Implant Dentistry and Related Research, ISSN 1523-0899, E-ISSN 1708-8208, Vol. 21, nr 1, s. 183-189Artikel, forskningsöversikt (Refereegranskat)
    Abstract [en]

    Background Oral implants have displayed clinical survival results at the 95%-99% level for over 10 years of follow up. Nevertheless, some clinical researchers see implant disease as a most common phenomenon. Oral implants are regarded to display disease in the form of mucositis or peri-implantitis. One purpose of the present article is to investigate whether a state of disease is necessarily occurring when implants display soft tissue inflammation or partially lose their bony attachment. Another purpose of this article is to analyze the mode of defense for implants that are placed in a bacteria rich environment and to analyze when an obtained steady state between tissue and the foreign materials is disturbed. Materials and Methods The present article is authored as a narrative review contribution. Results Evidence is presented that further documents the fact that implants are but foreign bodies that elicit a foreign body response when placed in bone tissue. The foreign body response is characterized by a bony demarcation of implants in combination with a chronic inflammation in soft tissues. Oral implants survive in the bacteria-rich environments where they are placed due to a dual defense system in form of chronic inflammation coupled to immunological cellular actions. Clear evidence is presented that questions the automatic diagnostics of an oral implant disease based on the finding of so called mucositis that in many instances represents but a normal tissue response to foreign body implants instead of disease. Furthermore, neither is marginal bone loss around implants necessarily indicative of a disease; the challenge to the implant represented by bone resorption may be successfully counteracted by local defense mechanisms and a new tissue-implant steady state may evolve. Similar reactions including chronic inflammation occur in the interface of orthopedic implants that display similarly good long-term results as do oral implants, if mainly evaluated based on revision surgery in orthopedic cases. The most common mode of failure of orthopedic implants is aseptic loosening which has been found coupled to a reactivation of the inflammatory- immune system. Conclusions Implants survive in the body due to balanced defense reactions in form of chronic inflammation and activation of the innate immune system. Ten year results of oral and hip /knee implants are hence in the 90+ percentage region. Clinical problems may occur with bone resorption that in most cases is successfully counterbalanced by the defense/healing systems. However, in certain instances implant failure will ensue characterized by bacterial attacks and/or by reactivation of the immune system that now will act to remove the foreign bodies from the tissues.

  • 8.
    Albrektsson, Tomas
    et al.
    Malmö högskola, Odontologiska fakulteten (OD).
    Sennerby, Lars
    Wennerberg, Ann
    Malmö högskola, Odontologiska fakulteten (OD).
    State of the art of oral implants2008Ingår i: Periodontology 2000, ISSN 0906-6713, E-ISSN 1600-0757, Vol. 47, nr 1, s. 15-26Artikel, forskningsöversikt (Övrigt vetenskapligt)
    Abstract [en]

    Objectives: The aim of this prospective study was to evaluate the Nobel Direct® and Nobel Perfect® one-piece implants (OPIs) when used for immediate function. Material and methods: Forty-eight patients were provided with 115 OPIs for loading with a provisional crown or a bridge within 24 h and followed for at least 12 months with clinical and radiographic examinations. A group of 97 patients previously treated under identical conditions by the same team with 380 two-piece implants (TPIs) for immediate loading in the mandible and maxilla served as the reference group. Results: Six (5.2%) OPIs failed during the follow-up due to extensive bone loss. Five (1.3%) implants failed in the reference group. After 1 year, the mean marginal bone loss was 2.1 mm (SD 1.3) for OPIs and 0.8 mm (SD 1) for TPIs. 20% of OPIs showed more than 3 mm of bone loss compared with 0.6% for TPIs. When compensating for vertical placement depth, OPIs still showed a lower marginal bone level and thus more exposed threads than TPIs. Depending on the criteria used, the success rate for OPIs was 46.1% or 72.2% compared with 85% or 91.6% for TPIs. Conclusions: The Nobel Direct® and Nobel Perfect® OPIs show lower success rates and more bone resorption than TPIs after 1 year in function. Factors such as implant design, insertion depth, rough surface towards the mucosa, in situ preparation and immediate loading may have an influence on the clinical outcome.

  • 9.
    Albrektsson, Tomas
    et al.
    Malmö universitet, Odontologiska fakulteten (OD). Univ Gothenburg, Dept Biomat, Gothenburg, Sweden.
    Wennerberg, Ann
    Univ Gothenburg, Dept Prosthodont, Gothenburg, Sweden.
    On osseointegration in relation to implant surfaces2019Ingår i: Clinical Implant Dentistry and Related Research, ISSN 1523-0899, E-ISSN 1708-8208, Vol. 21, nr S1, s. 4-7Artikel, forskningsöversikt (Refereegranskat)
    Abstract [en]

    Background The understanding of mechanisms of osseointegration as well as applied knowledge about oral implant surfaces are of paramount importance for successful clinical results. Purpose The aim of the present article is to present an overview of osseointegration mechanisms and an introduction to surface innovations with relevance for osseointegration that will be published in the same supplement of Clinical Implant Dentistry and Related Research. Materials and Methods The present article is a narrative review of some osseointegration and implant surface-related details. Results and Conclusions Osseointegration has a changed definition since it is realized today that oral implants are but foreign bodies and that this fact explains osseointegration as a protection mechanism of the tissues. Given adequate stability, bone tissue is formed around titanium implants to shield them from the tissues. Oral implant surfaces may be characterized by microroughness and nanoroughness, by surface chemical composition and by physical and mechanical parameters. An isotropic, moderately rough implant surface such as seen on the TiUnite device has displayed improved clinical results compared to previously used minimally rough or rough surfaces. However, there is a lack of clinical evidence supporting any particular type of nanoroughness pattern that, at best, is documented with results from animal studies. It is possible, but as yet unproven, that clinical results may be supported by a certain chemical composition of the implant surface. The same can be said with respect to hydrophilicity of implant surfaces; positive animal data may suggest some promise, but there is a lack of clinical evidence that hydrophilic implants result in improved clinical outcome of more hydrophobic surfaces. With respect to mechanical properties, it seems obvious that those must be encompassing the loading of oral implants, but we need more research on the mechanically ideal implant surface from a clinical aspect.

  • 10.
    Alenezi, Ali
    et al.
    Malmö universitet, Odontologiska fakulteten (OD). Malmö universitet, Biofilms Research Center for Biointerfaces. Department of Prosthodontics, College of Dentistry, Qassim University, Buraidah, Saudi Arabia.
    Chrcanovic, Bruno
    Malmö universitet, Odontologiska fakulteten (OD). Malmö universitet, Biofilms Research Center for Biointerfaces.
    Wennerberg, Ann
    Malmö universitet, Odontologiska fakulteten (OD). Malmö universitet, Biofilms Research Center for Biointerfaces.
    Effects of Local Drug and Chemical Compound Delivery on Bone Regeneration Around Dental Implants in Animal Models: A Systematic Review and Meta-Analysis2018Ingår i: International Journal of Oral & Maxillofacial Implants, ISSN 0882-2786, E-ISSN 1942-4434, Vol. 33, nr 1, s. e1-e18Artikel, forskningsöversikt (Refereegranskat)
    Abstract [en]

    Purpose: One of the suggested methods for enhancing osseointegration is the local application of drug agents around implant surfaces. The aim of this review was to evaluate the methods most commonly used for local drug and chemical compound delivery to implant sites and assess their influence on osseointegration. Materials and Methods: An electronic search was undertaken in three databases (PubMed, Scopus, Embase). The search was limited to animal experiments using endosseous implants combined with local drug delivery systems. Meta-analyses were performed for the outcome bone-to-implant contact (BIC). Results: Sixty-one studies met the inclusion criteria. Calcium phosphate (CaP), bisphosphonates (BPs), and bone morphogenetic proteins (BMPs) were the most commonly used chemical compounds. There were two main methods for local drug delivery at the bone-implant interface: (1) directly from an implant surface by coating or immobilizing techniques, and (2) the local application of drugs to the implant site, using carriers. There was a statistically significant increase in BIC for both local drug delivery methods (P = .02 and P < .0001, respectively) compared with the control methods. There was a statistically significant increase in BIC when CaP (P = .0001) and BMPs (P = .02) were either coating implants or were delivered to the implant site, in comparison to when drugs were not used. The difference was not significant for the use of BPs (P = .15). Conclusion: It is suggested that the use of local chemical compound delivery systems around implants could significantly improve implant osseointegration in animal models. It is a matter of debate whether these in vivo results might have some significant effect in the human clinical setting in the long term.

  • 11.
    Alenezi, Ali
    et al.
    Malmö universitet, Odontologiska fakulteten (OD). Malmö universitet, Biofilms Research Center for Biointerfaces. Department of Prosthodontics, College of Dentistry, Qassim University, Buraidah, Saudi Arabia.
    Galli, Silvia
    Malmö universitet, Odontologiska fakulteten (OD). Malmö universitet, Biofilms Research Center for Biointerfaces.
    Atefyekta, Saba
    Department of Chemistry and Chemical Engineering, Chalmers University of Technology, Göteborg, Sweden.
    Andersson, Martin
    Department of Chemistry and Chemical Engineering, Chalmers University of Technology, Göteborg, Sweden.
    Wennerberg, Ann
    Department of Prosthodontics/Dental Materials Science, Institute of Odontology, Sahlgrenska Academy, University of Gothenburg, Göteborg, Sweden.
    Osseointegration effects of local release of strontium ranelate from implant surfaces in rats2019Ingår i: Journal of materials science. Materials in medicine, ISSN 0957-4530, E-ISSN 1573-4838, Vol. 30, nr 10, artikel-id 116Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background: Numerous studies have reported the beneficial effects of strontium on bone growth, particularly by stimulating osteoblast proliferation and differentiation. Thus, strontium release around implants has been suggested as one possible strategy to enhance implant osseointegration. Aim: This study aimed to evaluate whether the local release of strontium ranelate (Sr-ranelate) from implants coated with mesoporous titania could improve bone formation around implants in an animal model. Materials and methods: Mesoporous titania (MT) thin coatings were formed utilizing the evaporation induced self-assembly (EISA) method using Pluronic (P123) with or without the addition of poly propylene glycol (PPG) to create materials with two different pore sizes. The MT was deposited on disks and mini-screws, both made of cp Ti grade IV. Scanning electron microscopy (SEM) was performed to characterize the MT using a Leo Ultra55 FEG instrument (Zeiss, Oberkochen, Germany). The MT was loaded with Sr-ranelate using soaking and the drug uptake and release kinetics to and from the surfaces were evaluated using quartz crystal microbalance with dissipation monitoring (QCM-D) utilizing a Q-sense E4 instrument. For the in vivo experiment, 24 adult rats were analyzed at two time points of implant healing (2 and 6 weeks). Titanium implants shaped as mini screws were coated with MT films and divided into two groups; supplied with Sr-ranelate (test group) and without Sr-ranelate (control group). Four implants (both test and control) were inserted in the tibia of each rat. The in vivo study was evaluated using histomorphometric analyses of the implant/bone interphase using optical microscopy. Results: SEM images showed the successful formation of evenly distributed MT films covering the entire surface with pore sizes of 6 and 7.2 nm, respectively. The QCM-D analysis revealed an absorption of 3300 ng/cm2 of Sr-ranelate on the 7.2 nm MT, which was about 3 times more than the observed amount on the 6 nm MT (1200 ng/cm2). Both groups showed sustained release of Sr-ranelate from MT coated disks. The histomorphometric analysis revealed no significant differences in bone implant contact (BIC) and bone area (BA) between the implants with Sr-ranelate and implants in the control groups after 2 and 6 weeks of healing (BIC with a p-value of 0.43 after 2 weeks and 0.172 after 6 weeks; BA with a p-value of 0.503 after 2 weeks, and 0.088 after 6 weeks). The mean BIC and BA values within the same group showed significant increase among all groups between 2 and 6 weeks. Conclusion: This study could not confirm any positive effects of Sr-ranelate on implant osseointegration.

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  • 12.
    Alenezi, Ali
    et al.
    Malmö högskola, Odontologiska fakulteten (OD).
    Naito, Yoshihito
    Malmö högskola, Odontologiska fakulteten (OD).
    Andersson, Martin
    Chrcanovic, Bruno
    Malmö högskola, Odontologiska fakulteten (OD).
    Wennerberg, Ann
    Malmö högskola, Odontologiska fakulteten (OD).
    Jimbo, Ryo
    Malmö högskola, Odontologiska fakulteten (OD).
    Characteristics of 2 Different Commercially Available Implants with or without Nanotopography2013Ingår i: International Journal of Dentistry, ISSN 1687-8728, E-ISSN 1687-8736, Vol. 2013, nr 769768, artikel-id 769768Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The aim of this study was to assess histologically and histomorphometrically the early bone forming properties after 3 weeks for 2 commercially available implants, one supposedly possessing nanotopography and one without, in a rabbit femur model. Twenty-four implants divided equally into 2 groups were utilized in this study. The first group (P-I MICRO+NANO) was a titanium oxide (TiO2) microblasted and noble gas ion bombarded surface while the second group (Ospol) was anodic oxidized surface with calcium and phosphate incorporation. The implants were placed in the rabbit femur unicortically and were allowed to heal for 3 weeks. After euthanasia, the samples were subjected to histologic sectioning and bone-implant contact and bone area were evaluated histomorphometrically under an optical microscope. The histomorphometric evaluation presented that the P-I MICRO+NANO implants demonstrated significantly higher new bone formation as compared to the Ospol implants. Within the limitations of this study, the results suggested that nanostructures presented significantly higher bone formation after 3 weeks in vivo, and the effect of chemistry was limited, which is indicative that nanotopography is effective at early healing periods.

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  • 13. Altmann, Brigitte
    et al.
    Kohal, Ralf-Joachim
    Steinberg, Thorsten
    Tomakidi, Pascal
    Bächle-Haas, Maria
    Wennerberg, Ann
    Malmö högskola, Odontologiska fakulteten (OD).
    Att, Wael
    Distinct cell functions of osteoblasts on UV-functionalized titanium- and zirconia-based implant materials are modulated by surface topography2013Ingår i: Tissue Engineering. Parts A, B and C, ISSN 2152-4947, E-ISSN 2152-4955, Vol. 19, nr 11, s. 850-863Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Though recent studies report decisive positive effects on cells, elicited by ultraviolet (UV)-induced bioactivation of biomaterial implant surfaces, they frequently employ cells other than of human origin or cells not representing oral implant targets. Therefore, the present study aims at exploring distinct cell functions of primary human alveolar bone osteoblasts (PHABO) in response to bioactivated microstructured titanium and zirconia implant surfaces with matched controls. UV-treatment significantly reduced surface carbon, while concomitantly increasing wettability. In case of titanium or zirconia biomaterial source of equal roughness, bioactivation did not significantly improve cell functions, including initial cell attachment, morphogenesis, proliferation, and gene expression of osteogenic biomarkers osteocalcin, alkaline phosphatase and collagen type I. However, cell functions discriminated surface roughness by either comparing titanium and zirconia or interindividual zirconia surfaces. While rough surfaces primarily favored primary adhesion, proliferation appeared improved on smooth surfaces, and gene expression seemed to be stronger modulated on the smoothest biomaterial. Our results show for the first time that bioactivation appears to be not the main causative for the observed modulation of the distinct cell functions analyzed in PHABO, but add to the body of evidence that they were more governed by surface architecture rather than by bioactivation.

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  • 14.
    Anderud, Jonas
    et al.
    Malmö högskola, Odontologiska fakulteten (OD).
    Abrahamsson, Peter
    Jimbo, Ryo
    Malmö högskola, Odontologiska fakulteten (OD).
    Isaksson, Sten
    Adolfsson, Erik
    Malmström, Johan
    Naito, Yoshihito
    Malmö högskola, Odontologiska fakulteten (OD).
    Wennerberg, Ann
    Malmö högskola, Odontologiska fakulteten (OD).
    Guided bone augmentation using ceramic space-maintaining devices: the impact of chemistry.2015Ingår i: Clinical, Cosmetic and Investigational Dentistry, E-ISSN 1179-1357, Vol. 7, s. 45-53Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The purpose of the study was to evaluate histologically, whether vertical bone augmentation can be achieved using a hollow ceramic space maintaining device in a rabbit calvaria model. Furthermore, the chemistry of microporous hydroxyapatite and zirconia were tested to determine which of these two ceramics are most suitable for guided bone generation. 24 hollow domes in two different ceramic materials were placed subperiosteal on rabbit skull bone. The rabbits were sacrificed after 12 weeks and the histology results were analyzed regarding bone-to-material contact and volume of newly formed bone. The results suggest that the effect of the microporous structure of hydroxyapatite seems to facilitate for the bone cells to adhere to the material and that zirconia enhance a slightly larger volume of newly formed bone. In conclusion, the results of the current study demonstrated that ceramic space maintaining devices permits new bone formation and osteoconduction within the dome.

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  • 15.
    Anderud, Jonas
    et al.
    Malmö högskola, Odontologiska fakulteten (OD). Maxillofacial Unit Halmstad, Region Halland, Halmstad, Sweden.
    Jimbo, Ryo
    Malmö högskola, Odontologiska fakulteten (OD).
    Abrahamsson, Peter
    Maxillofacial Unit Halmstad, Region Halland, Halmstad, Sweden.
    Adolfsson, Erik
    Swerea, IVF, Mölndal, Sweden.
    Malmström, Johan
    Maxillofacial Unit Halmstad, Region Halland, Halmstad, Sweden.
    Wennerberg, Ann
    Malmö högskola, Odontologiska fakulteten (OD).
    The impact of surface roughness and permeability in hydroxyapatite bone regeneration membranes2016Ingår i: Clinical Oral Implants Research, ISSN 0905-7161, E-ISSN 1600-0501, Vol. 27, nr 8, s. 1047-1054Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background One of the crucial aspects in guided bone regeneration is the space maintenance. This is normally created by a membrane, which should primarily be accepted by the surrounding tissues without causing any adverse reactions. The impact of surface topography, biological acceptance as well as permeability of these membranes has been carefully discussed in the literature. Purpose The purpose of this study was to evaluate histologically the bone forming properties inside of hollow hydroxyapatite space-maintaining devices with different inner surfaces and different permeabilities in an animal calvaria model in vivo. Materials and methods A total of 36 hollow domes with three different designs made of hydroxyapatite were surgically attached to the skulls of rabbits. Group 1 had a moderately rough inner surface. Group 2 had a smooth inner surface. Group 3 had the same properties as Group 1 but had macroscopic holes on the top. The domes were left to heal for 12 weeks and were then processed for undecalcified ground sectioning. Histological evaluations were performed using a light microscope and scanning electron microscopy. The bone–implant contact (BIC) percentage along the device was calculated. Results The median percentage of BIC was higher for Group 1 compared with Group 2 (P = 0.004). Group 1 produced a larger median BIC compared with Group 3 (P < 0.0001). Conclusions Within the limits of this preclinical study, these findings suggest that a moderately rough inner surface of a ceramic membrane along with a non-permeable device produces more bone than a smooth inner surface.

  • 16.
    Anderud, Jonas
    et al.
    Malmö högskola, Odontologiska fakulteten (OD).
    Jimbo, Ryo
    Malmö högskola, Odontologiska fakulteten (OD).
    Abrahamsson, Peter
    Isaksson, Sten G
    Adolfsson, Erik
    Malmstrom, Johan
    Kozai, Yusuke
    Hallmer, Fredrik
    Malmö högskola, Odontologiska fakulteten (OD).
    Wennerberg, Ann
    Malmö högskola, Odontologiska fakulteten (OD).
    Guided bone augmentation using a ceramic space-maintaining device2014Ingår i: Oral surgery, oral medicine, oral pathology and oral radiology, ISSN 2212-4403, E-ISSN 2212-4411, Vol. 118, nr 5, s. 532-538Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Objective. The purpose of this study was to evaluate 3-dimensionally whether vertical bone augmentation can be achieved using a hollow hydroxyapatite space-maintaining device in a rabbit calvarial model. Furthermore, different inner surface topographies, different permeabilities, and different porosities of the ceramic were tested to determine the optimal conditions for bone regeneration.

  • 17. Arvidsson, A
    et al.
    Diogo Löfgren, Christina
    Malmö högskola, Odontologiska fakulteten (OD).
    Christersson, Cecilia
    Malmö högskola, Odontologiska fakulteten (OD).
    Glantz, Per-Olof
    Wennerberg, Ann
    Malmö högskola, Odontologiska fakulteten (OD).
    Characterisation of Structures in Salivary Secretion Film Forma-tion. An Experimental Study with Atomic Force Microscopy2004Ingår i: Biofouling (Print), ISSN 0892-7014, E-ISSN 1029-2454, Vol. 20, nr 3, s. 181-188Artikel i tidskrift (Övrigt vetenskapligt)
    Abstract [en]

    The purpose of the present study was to characterise the structure dynamics of pure salivary secretions retained on controlled surfaces with different surface energies in the early stage of salivary film formation. Germanium prisms prepared to have either low surface energy of medium surface energy were incubated in fresh secretions of either human parotid saliva (HPS) or human submandibular/sublingual saliva (HSMSLS) for 15,90 and 180 min. After controlled rinsing with distilled water, the surfaces were air dried and thereafter imaged with atomic force microscopy (AFM). The amount of adsorbed material and the size of the structures detected increased with increased saliva exposure time. the film thicknesses varied from 10 to 160 nm, and both HPS and HSMSLS films contained structures with diameters varying from 40 nm to 2 microm. Some of these were clustered into special formations. The HPS films exhibited a more granular morphology than the HSMSLS films. Furthermore, branched lines were detected on the low surface energy germanium prisms incubated in saliva. the results indicate that exposure time, surface energy, and type of salivary secretion all are factors affecting the adsorption characteristics of salivary films.

  • 18. Barkarmo, Sargon
    et al.
    Wennerberg, Ann
    Malmö högskola, Odontologiska fakulteten (OD).
    Hoffman, Maria
    Kjellin, Per
    Breding, Karin
    Handa, Paul
    Stenport, Victoria
    Nano-hydroxyapatite-coated PEEK implants: a pilot study in rabbit bone2013Ingår i: Journal of Biomedical Materials Research. Part A, ISSN 1549-3296, E-ISSN 1552-4965, Vol. 101A, nr 2, s. 465-471Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Osseointegration of surface-modified polyetheretherketone (PEEK) implants was studied in vivo. A total of 18 cylinder-shaped PEEK implants were inserted in the femurs of nine New Zealand rabbits; half were coated with nanocrystalline hydroxyapatite (nanoHA) and half were uncoated controls. Healing time was 6 weeks. Samples were retrieved with the implant and surrounding tissue, processed to cut and ground sections, and analyzed histomorphometrically. The implant surfaces were analyzed with optical interferometry, scanning electron microscopy (SEM), atomic force microscopy, and X-ray photoelectron spectroscopy (XPS). NanoHA-coated PEEK surfaces had lower height deviation (Sa) than controls [mean ± SD: 0.41 μm (± 0.14) vs. 0.96 μm (± 0.28)]. SEM images showed the nanoHA crystals as a thin layer on the polymer surface. XPS analysis of the coated implants showed a Ca/P ratio of 1.67. Histomorphometry indicated that the nanoHA-coated implants had more bone-to-implant contact [16% (± 4.7) vs. 13% (± 9.3)] and more bone area [52% (± 9.5) vs. 45% (± 11.9)]. We found no difference between smooth nanoHA-coated cylinder-shaped PEEK implants and uncoated controls. However, higher mean bone-to-implant contact indicated better osseointegration in the coated implants than in the uncoated controls. The large number of lost implants was interpreted as a lack of primary stability due to implant design.

  • 19. Bougas, Kostas
    et al.
    Franke Stenport, Victoria
    Currie, Fredrik
    Wennerberg, Ann
    Malmö högskola, Odontologiska fakulteten (OD).
    In vitro Evaluation of Calcium Phosphate Precipitation on Possibly Bioactive Titanium Surfaces in the Presence of Laminin2011Ingår i: Journal of Oral & Maxillofacial Research, E-ISSN 2029-283X, Vol. 2, nr 3, artikel-id e3Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Objectives: The aim of the present study was to evaluate calcium phosphate precipitation and the amount of precipitated protein on three potentially bioactive surfaces when adding laminin in simulated body fluid. Material and Methods: Blasted titanium discs were prepared by three different techniques claimed to provide bioactivity: alkali and heat treatment (AH), anodic oxidation (AO) or hydroxyapatite coating (HA). A blasted surface incubated in laminin-containing simulated body fuid served as a positive control (B) while a blasted surface incubated in non laminin-containing simulated body fuid served as a negative control (B-). The immersion time was 1 hour, 24 hours, 72 hours and 1 week. Surface topography was investigated by interferometry and morphology by Scanning Electron Microscopy (SEM). Analysis of the precipitated calcium and phosphorous was performed by Energy Dispersive X-ray Spectroscopy (EDX) and the adsorbed laminin was quantified by iodine (125I) labeling. Results: SEM demonstrated that all specimens except for the negative control were totally covered with calcium phosphate (CaP) after 1 week. EDX revealed that B- demonstrated lower sum of Ca and P levels compared to the other groups after 1 week. Iodine labeling demonstrated that laminin precipitated in a similar manner on the possibly bioactive surfaces as on the positive control surface. Conclusions: Our results indicate that laminin precipitates equally on all tested titanium surfaces and may function as a nucleation center thus locally elevating the calcium concentration. Nevertheless further studies are required to clarify the role of laminin in the interaction of biomaterials with the host bone tissue.

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  • 20. Bougas, Kostas
    et al.
    Franke Stenport, Victoria
    Tengvall, Pentti
    Currie, Fredrik
    Wennerberg, Ann
    Malmö högskola, Odontologiska fakulteten (OD).
    Laminin coating promotes calcium phosphate precipitation on titanium discs in vitro2011Ingår i: Journal of Oral & Maxillofacial Research, E-ISSN 2029-283X, Vol. 2, nr 4, artikel-id e5Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Objectives: The objective of this study was to investigate the effect of a laminin coating on calcium phosphate precipitation on three potentially bioactive titanium surfaces in simulated body fluid. Material and Methods: Blasted titanium discs were prepared by alkali and heat treatment (AH), anodic oxidation (AO) or hydroxyapatite coating (HA) and subsequently coated with laminin. A laminin coated blasted surface (B) served as a positive control while a blasted non coated (B-) served as a negative control. Surface morphology was examined by Scanning Electron Microscopy (SEM). The analysis of the precipitated calcium and phosphorous was performed by Energy Dispersive X-ray Spectroscopy (EDX). Results: The thickness of the laminin coating was estimated at 26 Å by ellipsometry. Interferometry revealed that the coating process did not affect any of the tested topographical parameters on μm level when comparing B to B-. After 2 weeks of incubation in SBF, the alkali-heat treated discs displayed the highest calcium phosphate deposition and the B group showed higher levels of calcium phosphate than the B- group. Conclusions: Our results suggest that laminin may have the potential to be used as a coating agent in order to enhance the osseoinductive performance of biomaterial surfaces, with the protein molecules possibly functioning as nucleation centres for apatite formation. Nevertheless, in vivo studies are required in order to clarify the longevity of the coating and its performance in the complex biological environment.

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  • 21.
    Bougas, Kostas
    et al.
    Malmö högskola, Odontologiska fakulteten (OD).
    Jimbo, Ryo
    Malmö högskola, Odontologiska fakulteten (OD).
    Vandeweghe, Stefan
    Malmö högskola, Odontologiska fakulteten (OD).
    Hayashi, Mariko
    Malmö högskola, Odontologiska fakulteten (OD).
    Bryington, Matthew
    Malmö högskola, Odontologiska fakulteten (OD).
    Kozai, Yusuke
    Schwartz-Filho, Humberto O
    Tovar, Nick
    Adolfsson, Erik
    Ono, Daisuke
    Coelho, Paulo G
    Wennerberg, Ann
    Malmö högskola, Odontologiska fakulteten (OD).
    Bone apposition to laminin-1 coated implants: histologic and 3D evaluation2013Ingår i: International Journal of Oral and Maxillofacial Surgery, ISSN 0901-5027, E-ISSN 1399-0020, Vol. 42, nr 5, s. 677-682Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Laminin-1 has been reported as one of the factors responsible for the nucleation of calcium phosphates and, in vitro, has been reported to selectively recruit osteoprogenitors. This article focused on its in vivo effects, and evaluated the effect of laminin-1 local application on osseointegration. Polished cylindrical hydroxyapatite implants were coated with laminin-1 (test) and the bone responses in the rabbit tibiae after 2 and 4 weeks were evaluated and compared to the non-coated implants (control). Before the samples were processed for histological sectioning, they were three-dimensionally analysed with micro computed tomography (μCT). Both evaluation methods were analysed with regards to bone area around the implant and bone to implant contact. From the histologic observation, new bone formation around the laminin-1 coated implant at 2 weeks seemed to have increased the amount of supporting bone around the implant, however, at 4 weeks, the two groups presented no notable differences. The two-dimensional and three-dimensional morphometric evaluation revealed that both histologic and three-dimensional analysis showed some tendency in favour of the test group implants, however there was no statistical significance between the test and control group results.

  • 22.
    Bougas, Kostas
    et al.
    Malmö högskola, Odontologiska fakulteten (OD).
    Jimbo, Ryo
    Malmö högskola, Odontologiska fakulteten (OD).
    Xue, Ying
    Mustafa, Kamal
    Wennerberg, Ann
    Malmö högskola, Odontologiska fakulteten (OD).
    Novel implant coating agent promotes gene expression of osteogenic markers in rats during early osseointegration2012Ingår i: International Journal of Biomaterials, ISSN 1687-8787, E-ISSN 1687-8795, Vol. 2012, artikel-id 579274Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The aim of this study was to evaluate the early bone response around laminin-1-coated titanium implants. Forty-five rats distributed in three equally sized groups were provided with one control (turned) and one test (laminin-1-coated) implant and were sacrificed after 3, 7, and 21 days. Real-time reverse-transcriptase polymerase chain reaction was performed for osteoblast markers (alkaline phosphatase, runt-related transcription factor 2, osteocalcin, type I collagen, and bone morphogenic protein 2), osteoclast markers (cathepsin K and tartrate-resistant acid phosphatase), inflammation markers (tumor necrosis factor α, interleukin 1β and interleukin 10), and integrin β1. Bone implant contact (BIC) and bone area (BA) were assessed and compared to the gene expression. After 3 days, the expression of bone markers was higher for the control group. After 7 days, the expression of integrin β1 and osteogenic markers was enhanced for the test group, while cathepsin K and inflammation markers were downregulated. No significant differences in BIC or BA were detected between test and control at any time point. As a conclusion, implant coating with laminin-1 altered gene expression in the bone-implant interface. However, traditional evaluation methods, as histomorphometry, were not adequately sensitive to detect such changes due to the short follow-up time.

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  • 23.
    Braian, Michael
    et al.
    Malmö högskola, Odontologiska fakulteten (OD).
    De Bruyn, Hugo
    Malmö högskola, Odontologiska fakulteten (OD).
    Fransson, Håkan
    Christersson, Cecilia
    Malmö högskola, Odontologiska fakulteten (OD).
    Wennerberg, Ann
    Malmö högskola, Odontologiska fakulteten (OD).
    Tolerance Measurements on Internal- and External-Hexagon Implants2014Ingår i: International Journal of Oral & Maxillofacial Implants, ISSN 0882-2786, E-ISSN 1942-4434, Vol. 29, nr 4, s. 846-852Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Purpose: To measure the horizontal machining tolerances of the interface between internal-and external-hexagon implants and analogs with corresponding components after delivery from the manufacturer. These values may be a valuable tool for evaluating increasing misfit caused by fabrication, processing, and wear. Materials and Methods: Seven implants and seven analogs with external-and internal-hexagon connections (Biomet 3i) with corresponding prefabricated gold cylinders and gold screws, prefabricated cylindric plastic cylinders, and laboratory screws were studied. One set of components from the external and internal groups was measured manually and digitally. Measurements from the test subjects were compared with identical measurements from the virtual model to obtain threshold values. The virtual model was then used to obtain optimally oriented cuts. Results: The horizontal machining tolerances for castable plastic abutments on external implants were 12 +/- 89 mu m, and for internal implants they were 86 +/- 47 mu m. Tolerance measurements on prefabricated gold abutments for external implants were 44 +/- 9 mu m, and for internal implants they were 58 +/- 28 mu m. Conclusion: The groups with metallic components showed the smallest tolerance at < 50 mu m for the external group and < 90 mu m for the internal group. The prefabricated plastic cylinder groups ranged from < 100 mu m for external and < 130 mu m for internal connection.

  • 24.
    Braian, Michael
    et al.
    Malmö högskola, Odontologiska fakulteten (OD).
    Jimbo, Ryo
    Malmö högskola, Odontologiska fakulteten (OD).
    Wennerberg, Ann
    Malmö högskola, Odontologiska fakulteten (OD).
    Production tolerance of additive manufactured polymeric objects for clinical applications2016Ingår i: Dental Materials, ISSN 0109-5641, E-ISSN 1879-0097, Vol. 32, nr 7, s. 853-861Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Objectives. To determine the production tolerance of four commercially available additive manufacturing systems. Methods. By reverse engineering annex A and B from the ISO_12836;2012, two geometrical figures relevant to dentistry was obtained. Object A specifies the measurement of an inlay shaped object and B a multi-unit specimen to simulate a four-unit bridge model. The objects were divided into x, y and z measurements, object A was divided into a total of 16 parameters and object B was tested for 12 parameters. The objects were designed digitally and manufactured by professionals in four different additive manufacturing systems; each system produced 10 samples of each objects Results. For object A, three manufacturers presented an accuracy of <100 mu m and one system showed an accuracy of <20 mu m For object B, all systems presented an accuracy of <100 mu m, and most parameters were <40 mu m. The standard deviation for most parameters were <40 mu m Significance. The growing interest and use of intra-oral digitizing systems stresses the use of computer aided manufacturing of working models. The additive manufacturing techniques has the potential to help us in the digital workflow. Thus, it is important to have knowledge about production accuracy and tolerances. This study presents a method to test additive manufacturing units for accuracy and repeatability. (C) 2016 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved

  • 25.
    Braian, Michael
    et al.
    Malmö universitet, Odontologiska fakulteten (OD).
    Jönsson, David
    Malmö universitet, Odontologiska fakulteten (OD).
    Kevci, Mir
    Malmö universitet, Odontologiska fakulteten (OD).
    Wennerberg, Ann
    Malmö universitet, Odontologiska fakulteten (OD).
    Geometrical accuracy of metallic objects produced with additive or subtractive manufacturing: A comparative in vitro study2018Ingår i: Dental Materials, ISSN 0109-5641, E-ISSN 1879-0097, Vol. 34, nr 7, s. 978-993Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Objective. To evaluate the accuracy and precision of objects produced by additive manufacturing systems (AM) for use in dentistry and to compare with subtractive manufacturing systems (SM). Methods. Ten specimens of two geometrical objects were produced by five different AM machines and one SM machine. Object A mimics an inlay-shaped object, while object B imitates a four-unit bridge model. All the objects were sorted into different measurement dimensions (x, y, z), linear distances, angles and corner radius. Results. None of the additive manufacturing or subtractive manufacturing groups presented a perfect match to the CAD file with regard to all parameters included in the present study. Considering linear measurements, the precision for subtractive manufacturing group was consistent in all axes for object A, presenting results of <0.050 mm. The additive manufacturing groups had consistent precision in the x-axis and y-axis but not in the z-axis. With regard to corner radius measurements, the SM group had the best overall accuracy and precision for both objects A and B when compared to the AM groups. Significance. Within the limitations of this in vitro study, the conclusion can be made that subtractive manufacturing presented overall precision on all measurements below 0.050 mm. The AM machines also presented fairly good precision, <0.150 mm, on all axes except for the z-axis. Knowledge regarding accuracy and precision for different production techniques utilized in dentistry is of great clinical importance. The dental community has moved from casting to milling and additive techniques are now being implemented. Thus all these production techniques need to be tested, compared and validated. (C) 2018 The Academy of Dental Materials. Published by Elsevier Inc. All rights reserved.

  • 26.
    Braian, Michael
    et al.
    Malmö universitet, Odontologiska fakulteten (OD).
    Wennerberg, Ann
    Department of Prosthodontics, Institute of Odontology, Sahlgrenska Academy, Gothenburg University, Gothenburg, Sweden.
    Trueness and precision of 5 intraoral scanners for scanning edentulous and dentate complete-arch mandibular casts: A comparative in vitro study2019Ingår i: The Journal of prosthetic dentistry (Print), ISSN 0022-3913, E-ISSN 1097-6841, Vol. 122, nr 2, s. 129-136Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Statement of problem. Limited information is available on the trueness and precision of intraoral scanners (IOSs) for scanning dentate and edentulous casts. Purpose. The purpose of this in vitro study was to evaluate the trueness and precision of 5 different IOS devices for scanning a dentate and an edentulous cast in a standardized way for short arches and complete arches. Material and methods. Five IOS devices were used to scan 2 computer metric measured casts using a coordinate measuring machine (CMM). Both were scanned 15 times. All scans were carried out by 1 experienced operator in a standardized way. One cast was edentulous, and 1 was dentate. Five cylindrical landmarks were added to each cast. These cylinders made the measurement of point-to-point distances possible, dividing the tests into cross-arch measurements and intercylindrical (short-arch) measurements. The Student t test, Mann-Whitney test, and Levene test for equality were used to calculate the difference between the edentulous and dentate scans for both cross-arch and intercylindrical measurements (alpha=.05). Results. For the cross-arch measurements on the edentulous scans, the trueness values ranged between 6 mu m (Emerald P1-P2) and 193 mu m (Omnicam P1-P5) and for the intercylindrical measurements, between 2 mu m (Itero P4-P5) and -103 mu m (CS 3600 P1-P2). For the dentate cast, the cross-arch trueness values ranged between 6 mu m (CS 3600 P1-P2) and 150 mu m (TRIOS 3 P1-P5) and for the intercylindrical measurements, between 4 mu m (Itero P4-P5) and -56 mu m (Emerald P4-P5). Conclusions. Significant differences were found in scanning edentulous and dentate scans for short arches and complete arches. Trueness for complete-arch scans were <193 mu m for edentulous scans and <150 mu m for dentate scans. Trueness for short-arch scans were <103 mu m for edentulous scans and <56 mu m for dentate scans.

  • 27. Bryington, Matthew S
    et al.
    Hayashi, Mariko
    Malmö högskola, Odontologiska fakulteten (OD).
    Kozai, Yusuke
    Andersson, Martin
    Vandeweghe, Stefan
    Wennerberg, Ann
    Malmö högskola, Odontologiska fakulteten (OD).
    Jimbo, Ryo
    Malmö högskola, Odontologiska fakulteten (OD).
    The influence of nano hydroxyapatite coating on osseointegration after extended healing periods2013Ingår i: Dental Materials, ISSN 0109-5641, E-ISSN 1879-0097, Vol. 29, nr 5, s. 514-520Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    OBJECTIVE: Studies observing early wound healing periods around dental implants demonstrate an implants ability to enhance osseointegration, the bone-implant interactions for extended healing periods though have not been thoroughly studied. METHODS: Twenty threaded titanium alloy (Ti6Al4V, Grade 5) implants were inserted bilaterally, half prepared to impart stable hydroxyapatite nanoparticles onto a sand blasted and acid etched surface (HA) and half with a non-coated control surface with only heat treatment (HT), into eighteen rabbit femurs. At 12 weeks, the bone-implant blocks were retrieved for micro computed tomography (μCT), histologic processing and histomorphometric evaluation. RESULTS: The bone-to-implant contact for the entire threaded portion of the implant revealed 57.1% (21.0) for the HT group and 38.8% (17.7) for the HA group with a total bone area within the threads 72.5% (13.9) (HT) and 59.7% (12.5) (HA). The 3D reconstructed μCT image corresponded to the histomorphometric results. SIGNIFICANCE: It is suggested that multiple factors such as the change in topography and chemistry may have influenced the outcomes.

  • 28. Buser, Daniel
    et al.
    Chen, Stephen T.
    Cochran, David
    Debruyn, Hugo
    Jemt, Torsten
    Koka, Sreenivas
    Nevins, Myron
    Sennerby, Lars
    Simion, Massimo
    Taylor, Thomas D.
    Albrektsson, Tomas
    Malmö högskola, Odontologiska fakulteten (OD).
    Wennerberg, Ann
    Malmö högskola, Odontologiska fakulteten (OD).
    Statements from the Estepona Consensus Meeting on Peri-implantitis2012Ingår i: Clinical Implant Dentistry and Related Research, ISSN 1523-0899, E-ISSN 1708-8208, Vol. 14, nr 6, s. 781-782Artikel i tidskrift (Refereegranskat)
  • 29.
    Cecchinato, Francesca
    et al.
    Malmö högskola, Odontologiska fakulteten (OD).
    Agha, Nezha Ahmad
    Martinez-Sanchez, Adela Helvia
    Luthringer, Berengere Julie Christine
    Feyerabend, Frank
    Willumeit-Roemer, Regine
    Jimbo, Ryo
    Malmö högskola, Odontologiska fakulteten (OD).
    Wennerberg, Ann
    Malmö högskola, Odontologiska fakulteten (OD).
    Influence of Magnesium Alloy Degradation on Undifferentiated Human Cells2015Ingår i: PLOS ONE, E-ISSN 1932-6203, Vol. 10, nr 11, artikel-id e0142117Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background Magnesium alloys are of particular interest in medical science since they provide compatible mechanical properties with those of the cortical bone and, depending on the alloying elements, they have the capability to tailor the degradation rate in physiological conditions, providing alternative bioresorbable materials for bone applications. The present study investigates the in vitro short-term response of human undifferentiated cells on three magnesium alloys and high-purity magnesium (Mg). Materials and Methods The degradation parameters of magnesium-silver (Mg2Ag), magnesium-gadolinium (Mg10Gd) and magnesium-rare-earth (Mg4Y3RE) alloys were analysed after 1, 2, and 3 days of incubation in cell culture medium under cell culture condition. Changes in cell viability and cell adhesion were evaluated by culturing human umbilical cord perivascular cells on corroded Mg materials to examine how the degradation influences the cellular development. Results and Conclusions The pH and osmolality of the medium increased with increasing degradation rate and it was found to be most pronounced for Mg4Y3RE alloy. The biological observations showed that HUCPV exhibited a more homogeneous cell growth on Mg alloys compared to high-purity Mg, where they showed a clustered morphology. Moreover, cells exhibited a slightly higher density on Mg2Ag and Mg10Gd in comparison to Mg4Y3RE, due to the lower alkalinisation and osmolality of the incubation medium. However, cells grown on Mg10Gd and Mg4Y3RE generated more developed and healthy cellular structures that allowed them to better adhere to the surface. This can be attributable to a more stable and homogeneous degradation of the outer surface with respect to the incubation time.

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  • 30.
    Cecchinato, Francesca
    et al.
    Malmö högskola, Odontologiska fakulteten (OD).
    Atefyekta, Saba
    Department of Chemistry and Chemical Engineering Applied Chemistry, Chalmers University of Technology, Gothenburg, Sweden.
    Wennerberg, Ann
    Malmö högskola, Odontologiska fakulteten (OD).
    Andersson, Martin
    Department of Chemistry and Chemical Engineering Applied Chemistry, Chalmers University of Technology, Gothenburg, Sweden.
    Jimbo, Ryo
    Malmö högskola, Odontologiska fakulteten (OD). Department of Applied Prosthodontics, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan.
    Davies, Julia R
    Malmö högskola, Odontologiska fakulteten (OD).
    Modulation of the nanometer pore size improves magnesium adsorption into mesoporous titania coatings and promotes bone morphogenic protein 4 expression in adhering osteoblasts2016Ingår i: Dental Materials, ISSN 0109-5641, E-ISSN 1879-0097, Vol. 32, nr 7, s. E148-E158Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Objective. Mesoporous (MP) titania films used as implant coatings have recently been considered as release systems for controlled administration of magnesium to enhance initial osteoblast proliferation in vitro. Tuning of the pore size in such titania films is aimed at increasing the osteogenic potential through effects on the total loading capacity and the release profile of magnesium. Methods. In this study, evaporation-induced self-assembly (EISA) was used with different structure-directing agents to form three mesoporous films with average pore sizes of 2 nm (MP1), 6 nm (MP2) and 7 nm (MP3). Mg adsorption and release was monitored using quartz crystal microbalance with dissipation (QCM-D). The film surfaces were characterized with atomic force microscopy (AFM), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The effect of different Mg release on osteogenesis was investigated in human fetal osteoblasts (hFOB) using pre-designed osteogenesis arrays and real-time polymerase chain reaction (RT-PCR Results. Results showed a sustained release from all the films investigated, with higher magnesium adsorption into MP1 and MP3 films. No significant differences were observed in the surface nanotopography of the films, either with or without the presence of magnesium. MP3 films (7 nm pore size) had the greatest effect on osteogenesis, up-regulating 15 bone-related genes after 1 week of hFOB growth and significantly promoting bone morphogenic protein (BMP4) expression after 3 weeks of growth Significance. The findings indicate that the increase in pore width on the nano scale significantly enhanced the bioactivity of the mesoporous coating, thus accelerating osteogenesis without creating differences in surface roughness. (C) 2016 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved

  • 31.
    Cecchinato, Francesca
    et al.
    Malmö högskola, Odontologiska fakulteten (OD). Malmö högskola, Biofilms Research Center for Biointerfaces.
    Karlsson, Johan
    Ferroni, Letizia
    Gardin, Chiara
    Galli, Silvia
    Malmö högskola, Odontologiska fakulteten (OD). Malmö högskola, Biofilms Research Center for Biointerfaces.
    Wennerberg, Ann
    Malmö högskola, Odontologiska fakulteten (OD). Malmö högskola, Biofilms Research Center for Biointerfaces.
    Zavan, Barbara
    Andersson, Martin
    Jimbo, Ryo
    Malmö högskola, Odontologiska fakulteten (OD). Malmö högskola, Biofilms Research Center for Biointerfaces.
    Osteogenic potential of human adipose-derived stromal cells on 3-dimensional mesoporous TiO2 coating with magnesium impregnation2015Ingår i: Materials science & engineering. C, biomimetic materials, sensors and systems, ISSN 0928-4931, E-ISSN 1873-0191, Vol. 52, s. 225-234Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The aim of this study was to evaluate the osteogenic response of human adipose-derived stromal cells (ADScs) to mesoporous titania (TiO2) coatings produced with evaporation-induced self-assembly method (EISA) and loaded with magnesium. Our emphasis with the magnesium release functionality was to modulate progenitor cell osteogenic differentiation under standard culture conditions. Osteogenic properties of the coatings were assessed for stromal cells by means of scanning electron microscopy (SEM) imaging, colorimetric mitochondrial viability assay (MTT), colorimetric alkaline phosphates activity (ALP) assay and real time RT-polymerase chain reaction (PCR). Using atomic force microscopy (AFM) it was shown that the surface expansion area (Sdr) was strongly enhanced by the presence of magnesium. From MTT results it was shown that ADSc viability was significantly increased on mesoporous surfaces compared to the non-porous one at a longer cell culture time. However, no differences were observed between the magnesium impregnated and non-impregnated surfaces. The alkaline phosphatase activity confirmed that ADSc started to differentiate into the osteogenic phenotype after 2weeks of culturing. The gene expression profile at 2weeks of cell growth showed that such coatings were capable to incorporate specific osteogenic markers inside their interconnected nano-pores and, at 3weeks, ADSc differentiated into osteoblasts. Interestingly, magnesium significantly promoted the osteopontin gene expression, which is an essential gene for the early biomaterial-cell osteogenic interaction.

  • 32.
    Cecchinato, Francesca
    et al.
    Malmö högskola, Odontologiska fakulteten (OD).
    Xue, Ying
    Karlsson, Johan
    He, Wenxiao
    Mustafa, Kamal
    Andersson, Martin
    Wennerberg, Ann
    Malmö högskola, Odontologiska fakulteten (OD).
    Jimbo, Ryo
    Malmö högskola, Odontologiska fakulteten (OD).
    In vitro evaluation of human fetal osteoblast response to magnesium loaded mesoporous TiO2 coating2014Ingår i: Journal of Biomedical Materials Research. Part A, ISSN 1549-3296, E-ISSN 1552-4965, Vol. 102, nr 11, s. 3862-3871Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This work aimed to evaluate the in vitro response of Transfected Human Foetal Osteoblast (hFOB) cultured on a magnesium-loaded mesoporous TiO2 coating. The application of mesoporous films on titanium implant surfaces has shown very promising potential to enhance osseointegration. This type of coating has the ability to act as a framework to sustain bioactive agents and different drugs. Magnesium is the element that, after calcium, is the most frequently used to dope titanium implant surfaces, since it is crucial for protein formation, growth factor expression, and aids for bone mineral deposition on implant surfaces. Mesoporous TiO2 films with an average pore-size of 6 nm were produced by the evaporation-induced self-assembly method (EISA) and deposited onto titanium discs. Magnesium loading was performed by soaking the mesoporous TiO2discs in a magnesium chloride solution. Surface characterization was con- ducted by SEM, XPS, optical interferometry, and AFM. Magnesium release profile was assessed at different time points using a Magnesium Detection kit. Cell morphology and spreading were observed with SEM. The cytoskeletal organization was stained with TRITC-conjugated Phalloidin and cell viability was evaluated through a mitochondrial colorimetric (MTT) assay. Furthermore, gene expression of bone markers and cell mineralization were analyzed by real time RT-PCR and alizarin-red staining, respectively. The surface chemical analysis by XPS revealed the successful adsorption of magnesium to the mesoporous coating. The AFM measurements revealed the presence of a nanostructured surface roughness. Osteoblasts viability and adhesion as well as the gene expression were unaffected by the addition of magnesium possibly due to its rapid burst release, however, were enhanced by the 3D nanostructure of the TiO2l ayer.

  • 33. Charyeva, Olga
    et al.
    Neilands, Jessica
    Malmö högskola, Odontologiska fakulteten (OD). Malmö högskola, Biofilms Research Center for Biointerfaces.
    Svensäter, Gunnel
    Malmö högskola, Odontologiska fakulteten (OD). Malmö högskola, Biofilms Research Center for Biointerfaces.
    Wennerberg, Ann
    Malmö högskola, Odontologiska fakulteten (OD). Malmö högskola, Biofilms Research Center for Biointerfaces.
    Bacterial Biofilm Formation on Resorbing Magnesium Implants2015Ingår i: Open Journal of Medical Microbiology, ISSN 2165-3372, Vol. 5, nr 1Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background: Implant-associated infections are a result of bacterial adhesion to an implant surface and subsequent biofilm formation at the implantation site. This study compares different magnesium materials based on their ability to resist bacterial adhesion as well as further biofilm formation. Material and Methods: The surfaces of four magnesium-based materials (Mg2Ag, Mg10Gd, WE43 and 99.99% pure Mg) were characterized using atomic force microscope. In addition, the samples were tested for their ability to resist biofilm formation. Planktonic bacteria of either S. epidermidis or E. faecalis were allowed to adhere to the magnesium surfaces for two hour followed by rinsing and, for S. epidermidis, further incubation of 24, 72 and 168 h was carried out. Results: E. faecalis had a significantly stronger adhesion to all magnesium surfaces compared to S. epidermidis (p = 0.001). Biofilm growth of S. epidermidis was different on various magnesium materials: the amount of bacteria increased up to 72 h but interestingly a significant decrease was seen at 168 h on Mg2Ag and WE43 surfaces. For pure Mg and Mg10Gd the biofilm formation reached plateau at 72 h. Surface characteristics of resorbable magnesium materials were changing over time, and the surface was generally less rough at 168 h compared to earlier time points. No correlation was found between the surface topology and the amount of adherent bacteria. Conclusion: In early stages of biofilm adhesion, no differences between magnesium materials were observed. However, after 72 h Mg2Ag and WE43 had the best ability to suppress S. epidermidis’ biofilm formation. Also, bacterial adhesion to magnesium materials was not dependent on samples’ surface topology.

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  • 34.
    Chowdhary, Ramesh
    et al.
    Malmö högskola, Odontologiska fakulteten (OD).
    Halldin, Anders
    Malmö högskola, Odontologiska fakulteten (OD).
    Jimbo, Ryo
    Malmö högskola, Odontologiska fakulteten (OD).
    Wennerberg, Ann
    Malmö högskola, Odontologiska fakulteten (OD).
    Evaluation of stress pattern generated through various thread designs of dental implants loaded in a condition of immediately after placement and on osseointegration: an FEA study2013Ingår i: Implant Dentistry, ISSN 1056-6163, E-ISSN 1538-2982, Vol. 22, nr 1, s. 91-96Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    PURPOSE: To determine the stress pattern generated through various thread design in experimental simulation models, when loaded immediately after placement and after osseointegration. METHODS: Three-dimensional (3D) models were designed using CATIA, computer-aided design modeling software. The study was planned in 2 stages. Eight 2D models were constructed of different thread forms, one set with frictionless and other with bonded for bone to implant interface and loaded vertically with 100 N. In Stage II, 6 3D models of the different threads embedded in the cortical bone were constructed and loaded vertically and obliquely. RESULTS: In 2D models, the von Mises stress concentrated at the crest in the bonded connection thread designs. The stress levels were in the range of 7 to 13 MPa. In the frictional implant bone interface, the thread designs had a clear effect on the stress levels in the bone. In the 3D analysis, the complete implant design affected the stress levels. CONCLUSIONS: The thread design affects the magnitude of the stress peak in the bone more effectively in immediately loaded (frictionless) implants than the osseointegrated (bonded) implants. Maximum stress was observed at the first thread in most of the osseointegrated implants.

  • 35.
    Chowdhary, Ramesh
    et al.
    Malmö högskola, Odontologiska fakulteten (OD).
    Halldin, Anders
    Malmö högskola, Odontologiska fakulteten (OD).
    Jimbo, Ryo
    Malmö högskola, Odontologiska fakulteten (OD).
    Wennerberg, Ann
    Malmö högskola, Odontologiska fakulteten (OD).
    Influence of Micro Threads Alteration on Osseointegration and Primary Stability of Implants: An FEA and In Vivo Analysis in Rabbits2015Ingår i: Clinical Implant Dentistry and Related Research, ISSN 1523-0899, E-ISSN 1708-8208, Vol. 17, nr 3, s. 562-569Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    PURPOSE: To describe the early bone tissue response to implants with and without micro threads designed to the full length of an oxidized titanium implant. MATERIALS AND METHODS: A pair of two-dimensional finite element models was designed using a computer aided three-dimensional interactive application files of an implant model with micro threads in between macro threads and one without micro threads. Oxidized titanium implants with (test implants n=20) and without (control implants n=20) micro thread were prepared. A total of 12 rabbits were used and each received four implants. Insertion torque while implant placement and removal torque analysis after 4 weeks was performed in nine rabbits, and histomorphometric analysis in three rabbits, respectively. RESULTS: Finite element analysis showed less stress accumulation in test implant models with 31Mpa when compared with 62.2 Mpa in control implant model. Insertion and removal torque analysis did not show any statistical significance between the two implant designs. At 4 weeks, there was a significant difference between the two groups in the percentage of new bone volume and bone-to-implant contact in the femur (p< .05); however, not in the tibia. CONCLUSIONS: The effect of micro threads was prominent in the femur suggesting that micro threads promote bone formation. The stress distribution supported by the micro threads was especially effective in the cancellous bone.

  • 36.
    Chowdhary, Ramesh
    et al.
    Malmö högskola, Odontologiska fakulteten (OD).
    Jimbo, Ryo
    Malmö högskola, Odontologiska fakulteten (OD).
    Thomsen, C S
    Carlsson, L
    Wennerberg, Ann
    Malmö högskola, Odontologiska fakulteten (OD).
    The osseointegration stimulatory effect of macrogeometry-modified implants: a study in the rabbit2014Ingår i: Clinical Oral Implants Research, ISSN 0905-7161, E-ISSN 1600-0501, Vol. 25, nr 9, s. 1051-5Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    OBJECTIVE: To investigate the bone stimulatory effect of compression forces through histomorphometric analyses of macrothreaded implants with microthreads in between.

    MATERIAL AND METHODS: Two sets of turned implants with different macrogeometries were prepared. The test group possessed microthreads in between macrothreads, and the control group had macrothreads only. The two-implant groups were placed in both the femur and the tibiae of 10 rabbits. After 4 weeks, the animals were sacrificed and were subjected to histologic processing and histomorphometry. On the prepared stained sections, the total bone area (BA), new BA and bone-to-implant (BIC) were calculated.

    RESULTS: The mean new BA% (SD) for the test group in the femur presented significantly higher values compared with the control group, being 32.84 (32.5) ± 6.04 and 27.31 (28.19) ± 5.66, respectively (P = 0.04). There were no differences for the new BA in the tibia or the total BA% for both bone types (P = 0.86, P = 0.131, and P = 0.131, respectively). The mean BIC% (SD) in the femur was 13.66 (11.49) ± 6.86 for the test group and 8.48 (7.92) ± 3.31 for the control group and in the tibia, 11.4 (11.88) ± 4.21 for the test group and 13.91 (12.06) ± 6.07 for the control group, respectively. There was no statistical significance among the groups tested.

    CONCLUSION: The modified implant macrogeometry with microthreads in between promoted effect in the femur. However, no statistical differences could be seen in the tibia, suggesting that the modification may be more effective in bone with poor bone quality, such as in the maxillary bone.

  • 37.
    Chowdhary, Ramesh
    et al.
    Malmö högskola, Odontologiska fakulteten (OD).
    Jimbo, Ryo
    Malmö högskola, Odontologiska fakulteten (OD).
    Thomsen, Christian
    Carlsson, Lennart
    Wennerberg, Ann
    Malmö högskola, Odontologiska fakulteten (OD).
    Biomechanical evaluation of macro and micro designed screw-type implants: an insertion torque and removal torque study in rabbits2013Ingår i: Clinical Oral Implants Research, ISSN 0905-7161, E-ISSN 1600-0501, Vol. 24, nr 3, s. 342-346Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    OBJECTIVE: To investigate the combined effect of macro and pitch shortened threads on primary and secondary stability during healing, but before dynamic loading. MATERIALS AND METHODS: Two sets of turned implants with different macro geometry were prepared. The test group possessed pitch shortened threads in between the large threads and the control group did not have thread alterations. The two implant groups were placed in both femur and tibiae of 10 lop-eared rabbits, and at the time of implant insertion, insertion torques were recorded. After 4 weeks, all implants were subjected to removal torque tests. RESULTS: The insertion torque values for the control and test groups for the tibia were 15.7 and 20.6 Ncm, respectively, and for the femur, 11.8, and 12.8 Ncm respectively. The removal torque values for the control and test groups in the tibia were 7.9 and 9.1 Ncm, respectively, and for the femur, 7.9 and 7.7 Ncm respectively. There was no statistically significant difference between the control and test groups. CONCLUSION: Under limited dynamic load, the addition of pitch shortened threads did not significantly improve either the primary or the secondary stability of the implants in bone.

  • 38.
    Chrcanovic, Bruno
    et al.
    Malmö högskola, Odontologiska fakulteten (OD).
    Albrektsson, Tomas
    Malmö högskola, Odontologiska fakulteten (OD).
    Wennerberg, Ann
    Malmö högskola, Odontologiska fakulteten (OD).
    Bisphosphonates and dental implants: A meta-analysis2016Ingår i: Quintessence International, ISSN 0033-6572, Vol. 47, nr 4, s. 329-342Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    OBJECTIVE: To test the null hypothesis of no difference in the implant failure rates, marginal bone loss, and postoperative infection for patients receiving or not receiving bisphosphonates, against the alternative hypothesis of a difference. METHOD AND MATERIALS: An electronic search was undertaken in October 2015 in PubMed/Medline, Web of Science, and Embase, plus hand-searching and databases of clinical trials. Eligibility criteria included clinical human studies, either randomized or not. RESULTS: A total of 18 publications were included in the review. Concerning implant failure, the meta-analysis found a risk ratio of 1.73 (95% confidence interval [CI] 1.21-2.48, P = .003) for patients taking bisphosphonates, when compared to patients not taking the medicament. The probability of an implant failure in patients taking bisphosphonates was estimated to be 1.5% (0.015, 95% CI 0.006- 0.023, standard error [SE] 0.004, P < .001). It cannot be suggested that bisphosphonates may affect the marginal bone loss of dental implants, due to a limited number of studies reporting this outcome. Due to a lack of sufficient information, meta-analysis for the outcome "postoperative infection" was not performed. CONCLUSION: The results of the present study cannot suggest that the insertion of dental implants in patients taking BPs affects the implant failure rates, due to a limited number of published studies, all characterized by a low level of specificity, and most of them dealing with a limited number of cases without a proper control group. Therefore, the real effect of BPs on the osseointegration and survival of dental implants is still not well established.

  • 39.
    Chrcanovic, Bruno
    et al.
    Malmö högskola, Odontologiska fakulteten (OD). Malmö högskola, Biofilms Research Center for Biointerfaces.
    Albrektsson, Tomas
    Department of Biomaterials, Göteborg University, Göteborg, Sweden.
    Wennerberg, Ann
    Malmö högskola, Odontologiska fakulteten (OD). Malmö högskola, Biofilms Research Center for Biointerfaces.
    Bone Quality and Quantity and Dental Implant Failure: A Systematic Review and Meta-analysis2017Ingår i: International Journal of Prosthodontics, ISSN 0893-2174, E-ISSN 1139-9791, Vol. 30, nr 3, s. 219-237Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Purpose: The aim of this study was to test the null hypothesis that there is no difference in implant failure rates, marginal bone loss, and postoperative infection for implants inserted in bone with different qualities and quantities according to the classification of Lekholm and Zarb. Materials and Methods: An electronic search was undertaken in January 2015 for randomized and nonrandomized human clinical studies. Results: A total of 94 publications were included. When bone sites of different qualities were considered, the results suggested the following comparative implant failure rates: 1 > 2, 1 > 3, 3 > 2, 4 > 1, 4 > 2, and 4 > 3. Sensitivity analyses suggested that when implants inserted in bone qualities 1 and 2 and 1 and 3 were compared, oxidized and sandblasted/acid-etched surfaces showed a decrease in significant difference in failures compared with turned implants. The same is not true for failure of implants inserted in bone quality 4 compared to failure of implants in all other bone qualities. When bone sites of different quantities were considered, the following comparative implant failure rates were observed: A > B, A > C, A < D, B < C, B < D, C < D, E > A, E > B, E > C, E > D. Due to insufficient information, meta-analyses for the outcomes postoperative infection and marginal bone loss were not performed. Conclusion: Sites with poorer bone quality and lack of bone volume may statistically affect implant failure rates. Implant surfaces may play a role in failure of implants in different bone qualities.

  • 40.
    Chrcanovic, Bruno
    et al.
    Malmö högskola, Odontologiska fakulteten (OD).
    Albrektsson, Tomas
    Malmö högskola, Odontologiska fakulteten (OD).
    Wennerberg, Ann
    Malmö högskola, Odontologiska fakulteten (OD).
    Bruxism and dental implants: a meta-analysis2015Ingår i: Implant Dentistry, ISSN 1056-6163, E-ISSN 1538-2982, Vol. 24, nr 5, s. 505-516Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    PURPOSE: To test the null hypothesis of no difference in the implant failure rates, postoperative infection, and marginal bone loss after the insertion of dental implants in bruxers compared with the insertion in non-bruxers against the alternative hypothesis of a difference. METHODS: An electronic search was undertaken in June 2014. Eligibility criteria included clinical studies, either randomized or not. RESULTS: Ten publications were included with a total of 760 implants inserted in bruxers (49 failures; 6.45%) and 2989 in non-bruxers (109 failures; 3.65%). Due to lack of information, meta-analyses for the outcomes "postoperative infection" and "marginal bone loss" were not possible. A risk ratio of 2.93 was found (95% confidence interval, 1.48-5.81; P = 0.002). CONCLUSIONS: These results cannot suggest that the insertion of dental implants in bruxers affects the implant failure rates due to a limited number of published studies, all characterized by a low level of specificity, and most of them deal with a limited number of cases without a control group. Therefore, the real effect of bruxing habits on the osseointegration and survival of endosteal dental implants is still not well established.

  • 41.
    Chrcanovic, Bruno
    et al.
    Malmö högskola, Odontologiska fakulteten (OD).
    Albrektsson, Tomas
    Malmö högskola, Odontologiska fakulteten (OD). Department of Biomaterials, Göteborg University, Göteborg, Sweden.
    Wennerberg, Ann
    Malmö högskola, Odontologiska fakulteten (OD).
    Dental implants in irradiated versus non-irradiated patients: a meta-analysis2016Ingår i: Head and Neck, ISSN 1043-3074, E-ISSN 1097-0347, Vol. 38, nr 3, s. 448-481Artikel, forskningsöversikt (Refereegranskat)
    Abstract [en]

    Background/Methods. The purpose of the present meta-analysis was to test the null hypothesis of no difference in dental implant failure rates, postoperative infection, and marginal bone loss for patients being rehabilitated by dental implants and being previously irradiated in the head and neck region versus non-irradiated patients, against the alternative hypothesis of a difference. Results/Conclusion. The study suggests that irradiation negatively affects the survival of implants, as well as the difference in implant location (maxilla vs. mandible), but there is no statistically significant difference in survival when implants are inserted before or after 12 months after radiotherapy. The study failed to support the effectiveness of hyperbaric oxygen therapy in irradiated patients. It was observed a tendency to lower survival rates of implants inserted in the patients submitted to higher irradiation doses. The results should be interpreted with caution due to the presence of uncontrolled confounding factors in the included studies.

  • 42.
    Chrcanovic, Bruno
    et al.
    Malmö högskola, Odontologiska fakulteten (OD).
    Albrektsson, Tomas
    Malmö högskola, Odontologiska fakulteten (OD). Department of Biomaterials, Göteborg University, Göteborg, Sweden.
    Wennerberg, Ann
    Malmö högskola, Odontologiska fakulteten (OD).
    Dental Implants in Patients Receiving Chemotherapy: A Meta-Analysis2016Ingår i: Implant Dentistry, ISSN 1056-6163, E-ISSN 1538-2982, Vol. 25, nr 2, s. 261-271Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Purpose: To test the null hypothesis of no difference in the implant failure rates, postoperative infection, and marginal bone loss for patients being rehabilitated by dental implants and being versus not being submitted to chemotherapy, against the alternative hypothesis of a difference. Methods: An electronic search without time or language restrictions was undertaken in May 2014 in PubMed/MEDLINE, Web of Science, Cochrane Oral Health Group Trials Register plus hand-searching. Eligibility criteria included clinical human studies, either randomized or not. Results: Nine publications were included. The results suggested that the insertion of dental implants in patients submitted or not submitted to chemotherapy did not affect the implant failure rates (risk ratio 1.02, 95% confidence interval 0.56-1.85; P = 0.95). Because of lack of enough information, meta-analyses for the outcomes "postoperative infection" and "marginal bone loss" were not performed. Conclusion: These results cannot suggest that the insertion of dental implants in patients submitted to chemotherapy may or may not affect the implant failure rates, because of a limited number of published studies, most of them characterized by a low level of specificity and dealing with a limited number of cases without a control group. The reliability and validity of the data collected and the potential for biases and confounding factors are some of the shortcomings of the present study.

  • 43.
    Chrcanovic, Bruno
    et al.
    Malmö högskola, Odontologiska fakulteten (OD).
    Albrektsson, Tomas
    Malmö högskola, Odontologiska fakulteten (OD).
    Wennerberg, Ann
    Malmö högskola, Odontologiska fakulteten (OD).
    Dental implants inserted in fresh extraction sockets versus healed sites: a systematic review and meta-analysis2015Ingår i: Journal of Dentistry, ISSN 0300-5712, E-ISSN 1879-176X, Vol. 43, nr 1, s. 16-41Artikel, forskningsöversikt (Refereegranskat)
    Abstract [en]

    OBJECTIVES: The purpose of the present review was to test the null hypothesis of no difference in the implant failure rates, postoperative infection and marginal bone loss for the insertion of dental implants in fresh extraction sockets compared to the insertion in healed sites, against the alternative hypothesis of a difference. METHODS: An electronic search was undertaken in July 2014. Eligibility criteria included clinical human studies, either randomized or not. RESULTS: The search strategy resulted in 73 publications, with 8241 implants inserted in sockets (330 failures, 4.00%), and 19,410 in healed sites (599 failures, 3.09%). The difference between the procedures significantly affected the failure rates (RR 1.58, 95% CI 1.27-1.95, P<0.0001). The difference was not statistically significant when studies evaluating implants inserted in maxillae or in mandibles were pooled, or when the studies using implants to rehabilitate patients with full-arch prostheses were pooled; however, it was significant for the studies that rehabilitated patients with implant-supported single crowns and for the controlled studies. There was no apparent significant effect of implants inserted in fresh extraction sockets on the occurrence of postoperative infection or on the magnitude of marginal bone loss. CONCLUSION: It is suggested that the insertion of implants in fresh extraction sockets affects the failure rates. However, it does not affect the marginal bone loss or the occurrence of postoperative infection. The results should be interpreted with caution due to the potential for biases and to the presence of uncontrolled confounding factors in the included studies, most of them not randomized. CLINICAL SIGNIFICANCE: The question whether immediate implants are more at risk for failure than implants placed in mature bone has received increasing attention in the last years. As the philosophies of treatment alter over time, a periodic review of the different concepts is necessary to refine techniques and eliminate unnecessary procedures. This would form a basis for optimum treatment.

  • 44.
    Chrcanovic, Bruno
    et al.
    Malmö högskola, Odontologiska fakulteten (OD).
    Albrektsson, Tomas
    Malmö högskola, Odontologiska fakulteten (OD).
    Wennerberg, Ann
    Malmö högskola, Odontologiska fakulteten (OD).
    Dental implants inserted in male versus female patients: a systematic review and meta-analysis2015Ingår i: Journal of Oral Rehabilitation, E-ISSN 1365-2842, Vol. 42, nr 9, s. 709-722Artikel, forskningsöversikt (Refereegranskat)
    Abstract [en]

    The aim of this meta-analysis was to test the null hypothesis of no difference in the failure rates, marginal bone loss (MBL) and post-operative infection for implants inserted in male or female patients, against the alternative hypothesis of a difference. An electronic search without time or language restrictions was undertaken in December 2014. Eligibility criteria included clinical human studies, either randomized or not. Ninety-one publications were included, with a total of 27,203 implants inserted in men (1185 failures), and 25,154 implants inserted in women (1039 failures). The results suggest that the insertion of dental implants in male patients statistically affected the implant failure rates (RR 1.21, 95% CI 1.07-1.37, P = 0.002). Due to the limited number of studies reporting results on MBL, it is difficult to estimate the real effect of the insertion of implants in different sexes on the marginal bone level. Due to lack of satisfactory information, meta-analysis for the outcome 'post-operative infection' was not performed. The results have to be interpreted with caution due to the presence of several confounding factors in the included studies.

  • 45.
    Chrcanovic, Bruno
    et al.
    Malmö högskola, Odontologiska fakulteten (OD).
    Albrektsson, Tomas
    Malmö högskola, Odontologiska fakulteten (OD).
    Wennerberg, Ann
    Malmö högskola, Odontologiska fakulteten (OD).
    Diabetes and oral implant failure: a systematic review2014Ingår i: Journal of Dental Research, ISSN 0022-0345, E-ISSN 1544-0591, Vol. 93, nr 9, s. 859-867Artikel, forskningsöversikt (Refereegranskat)
    Abstract [en]

    The aim of this systematic review and meta-analysis was to investigate whether there are any effects of diabetes mellitus on implant failure rates, postoperative infections, and marginal bone loss. An electronic search without time or language restrictions was undertaken in March 2014. The present review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Eligibility criteria included clinical human studies. The search strategy resulted in 14 publications. The I (2) statistic was used to express the percentage of total variation across studies due to heterogeneity. The inverse variance method was used for the random effects model when heterogeneity was detected or for the fixed effects model when heterogeneity was not detected. The estimates of an intervention for dichotomous outcomes were expressed in risk ratio and in mean difference in millimeters for continuous outcomes, both with a 95% confidence interval. There was a statistically significant difference (p = .001; mean difference = 0.20, 95% confidence interval = 0.08, 0.31) between diabetic and non-diabetic patients concerning marginal bone loss, favoring non-diabetic patients. A meta-analysis was not possible for postoperative infections. The difference between the patients (diabetic vs. non-diabetic) did not significantly affect implant failure rates (p = .65), with a risk ratio of 1.07 (95% confidence interval = 0.80, 1.44). Studies are lacking that include both patient types, with larger sample sizes, and that report the outcome data separately for each group. The results of the present meta-analysis should be interpreted with caution because of the presence of uncontrolled confounding factors in the included studies.

  • 46.
    Chrcanovic, Bruno
    et al.
    Malmö högskola, Odontologiska fakulteten (OD).
    Albrektsson, Tomas
    Malmö högskola, Odontologiska fakulteten (OD).
    Wennerberg, Ann
    Malmö högskola, Odontologiska fakulteten (OD).
    Flapless versus conventional flapped dental implant surgery: a meta-analysis2014Ingår i: PLOS ONE, E-ISSN 1932-6203, Vol. 9, nr 6, artikel-id e100624Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The aim of this study was to test the null hypothesis of no difference in the implant failure rates, postoperative infection, and marginal bone loss for patients being rehabilitated by dental implants being inserted by a flapless surgical procedure versus the open flap technique, against the alternative hypothesis of a difference. An electronic search without time or language restrictions was undertaken in March 2014. Eligibility criteria included clinical human studies, either randomized or not. The search strategy resulted in 23 publications. The I2 statistic was used to express the percentage of the total variation across studies due to heterogeneity. The inverse variance method was used for random-effects model or fixed-effects model, when indicated. The estimates of relative effect were expressed in risk ratio (RR) and mean difference (MD) in millimeters. Sixteen studies were judged to be at high risk of bias, whereas two studies were considered of moderate risk of bias, and five studies of low risk of bias. The funnel plots indicated absence of publication bias for the three outcomes analyzed. The test for overall effect showed that the difference between the procedures (flapless vs. open flap surgery) significantly affect the implant failure rates (P = 0.03), with a RR of 1.75 (95% CI 1.07-2.86). However, a sensitivity analysis revealed differences when studies of high and low risk of bias were pooled separately. Thus, the results must be interpreted carefully. No apparent significant effects of flapless technique on the occurrence of postoperative infection (P = 0.96; RR 0.96, 95% CI 0.23-4.03) or on the marginal bone loss (P = 0.16; MD -0.07 mm, 95% CI -0.16-0.03) were observed.

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  • 47.
    Chrcanovic, Bruno
    et al.
    Malmö högskola, Odontologiska fakulteten (OD).
    Albrektsson, Tomas
    Malmö högskola, Odontologiska fakulteten (OD).
    Wennerberg, Ann
    Malmö högskola, Odontologiska fakulteten (OD).
    Immediate nonfunctional versus immediate functional loading and dental implant failure rates: a systematic review and meta-analysis2014Ingår i: Journal of Dentistry, ISSN 0300-5712, E-ISSN 1879-176X, Vol. 42, nr 9, s. 1052-1059Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    OBJECTIVES: The purpose of the present review was to test the null hypothesis of no difference in the implant failure rates, postoperative infection, and marginal bone loss for patients being rehabilitated using dental implants with immediate nonfunctional loading (INFL) compared to immediate functional loading (IFL), against the alternative hypothesis of a difference. METHODS: An electronic search without time or language restrictions was undertaken in March 2014. Eligibility criteria included clinical human studies, either randomized or not. The estimates of relative effect were expressed in risk ratio (RR) and mean difference (MD) in millimeters. RESULTS: 1059 studies were identified and 11 studies were included, of which 7 were of high risk of bias, whereas four studies were of low risk of bias. The results showed that the procedure used (nonfunctional vs. functional) did not significantly affect the implant failure rates (P=0.70), with a RR of 0.87 (95% CI 0.44-1.75). The wide CI demonstrates uncertainty about the effect size. The analysis of postoperative infection was not possible due to lack of data. No apparent significant effects of non-occlusal loading on the marginal bone loss (MD 0.01mm, 95% CI -0.04-0.06; P=0.74) were observed. CONCLUSIONS: The results of this study suggest that the differences in occlusal loading between INFL and IFL might not affect the survival of these dental implants and that there is no apparent significant effect on the marginal bone loss. CLINICAL SIGNIFICANCE: There has been a controversy concerning whether dental implants should be subjected to immediate functional or nonfunctional loading. As the philosophies of treatment may alter over time, a periodic review of the different concepts is necessary to refine techniques and eliminate unnecessary procedures. This would form a basis for optimum treatment.

  • 48.
    Chrcanovic, Bruno
    et al.
    Malmö högskola, Odontologiska fakulteten (OD).
    Albrektsson, Tomas
    Malmö högskola, Odontologiska fakulteten (OD).
    Wennerberg, Ann
    Malmö högskola, Odontologiska fakulteten (OD).
    Immediately loaded non-submerged versus delayed loaded submerged dental implants: a meta-analysis2015Ingår i: International Journal of Oral and Maxillofacial Surgery, ISSN 0901-5027, E-ISSN 1399-0020, Vol. 44, nr 4, s. 493-506Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The purpose of the present meta-analysis was to test the null hypothesis of no difference in the implant failure rate, postoperative infection, and marginal bone loss for patients being rehabilitated with immediately loaded non-submerged dental implants or delayed loaded submerged implants, against the alternative hypothesis of a difference. An electronic search without time or language restrictions was undertaken in March 2014. Eligibility criteria included clinical human studies, either randomized or not. The search strategy resulted in 28 publications. The inverse variance method was used for a random- or fixed-effects model, depending on the heterogeneity. The estimates of an intervention were expressed as the risk ratio (RR) and mean difference (MD) in millimetres. Twenty-three studies were judged to be at high risk of bias, one at moderate risk of bias, and four studies were considered at low risk of bias. The difference between procedures (submerged vs. non-submerged implants) significantly affected the implant failure rate (P = 0.02), with a RR of 1.78 (95% confidence interval (CI) 1.12-2.83). There was no apparent significant effect of non-submerged dental implants on the occurrence of postoperative infection (P = 0.29; RR 2.13, CI 0.52-8.65) or on marginal bone loss (P = 0.77; MD -0.03, 95% CI -0.23 to 0.17).

  • 49.
    Chrcanovic, Bruno
    et al.
    Malmö högskola, Odontologiska fakulteten (OD).
    Albrektsson, Tomas
    Malmö högskola, Odontologiska fakulteten (OD).
    Wennerberg, Ann
    Malmö högskola, Odontologiska fakulteten (OD).
    Periodontally compromised vs. periodontally healthy patients and dental implants: a systematic review and meta-analysis2014Ingår i: Journal of Dentistry, ISSN 0300-5712, E-ISSN 1879-176X, Vol. 42, nr 12, s. 1509-1527Artikel, forskningsöversikt (Refereegranskat)
    Abstract [en]

    OBJECTIVES: To test the null hypothesis of no difference in the implant failure rates, postoperative infection, and marginal bone loss for the insertion of dental implants in periodontally compromised patients (PCPs) compared to the insertion in periodontally healthy patients (PHPs), against the alternative hypothesis of a difference. METHODS: An electronic search without time or language restrictions was undertaken in March 2014. Eligibility criteria included clinical human studies, either randomized or not. RESULTS: 2768 studies were identified in the search strategy and 22 studies were included. The estimates of relative effect were expressed in risk ratio (RR) and mean difference (MD) in millimetres. All studies were judged to be at high risk of bias, none were randomized. A total of 10,927 dental implants were inserted in PCPs (587 failures; 5.37%), and 5881 implants in PHPs (226 failures; 3.84%). The difference between the patients significantly affected the implant failure rates (RR 1.78, 95% CI 1.50-2.11; P<0.00001), also observed when only the controlled clinical trials were pooled (RR 1.97, 95% CI 1.38-2.80; P=0.0002). There were significant effects of dental implants inserted in PCPs on the occurrence of postoperative infections (RR 3.24, 95% CI 1.69-6.21; P=0.0004) and in marginal bone loss (MD 0.60, 95% CI 0.33-0.87; P<0.0001) when compared to PHPs. CONCLUSIONS: The present study suggests that an increased susceptibility for periodontitis may also translate to an increased susceptibility for implant loss, loss of supporting bone, and postoperative infection. The results should be interpreted with caution due to the presence of uncontrolled confounding factors in the included studies, none of them randomized. CLINICAL SIGNIFICANCE: There is some evidence that patients treated for periodontitis may experience more implant loss and complications around implants including higher bone loss and peri-implantitis than non-periodontitis patients. As the philosophies of treatment may alter over time, a periodic review of the different concepts is necessary to refine techniques and eliminate unnecessary procedures. This would form a basis for optimum treatment.

  • 50.
    Chrcanovic, Bruno
    et al.
    Malmö högskola, Odontologiska fakulteten (OD).
    Albrektsson, Tomas
    Malmö högskola, Odontologiska fakulteten (OD).
    Wennerberg, Ann
    Malmö högskola, Odontologiska fakulteten (OD).
    Platform switch and dental implants: a meta-analysis2015Ingår i: Journal of Dentistry, ISSN 0300-5712, E-ISSN 1879-176X, Vol. 43, nr 6, s. 629-646Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    OBJECTIVES: To test the null hypothesis of no difference in the implant failure rates, marginal bone loss (MBL) and postoperative infection in patients who received platform-switched implants or platform-matched implants, against the alternative hypothesis of a difference. DATA: Main search terms used in combination: dental implant, oral implant, platform switch, switched platform, platform mismatch, and dental implant-abutment design. SOURCES: An electronic search without time or language restrictions was undertaken in December/2014 in PubMed/Medline, Web of Science, Cochrane Oral Health Group Trials Register plus hand-searching. STUDY SELECTION: Eligibility criteria included clinical human studies, either randomized or not. CONCLUSIONS: Twenty-eight publications were included, with a total of 1216 platform-switched implants (16 failures; 1.32%) and 1157 platform-matched implants (13 failures; 1.12%). There was less MBL loss at implants with platform-switching than at implants with platform-matching (mean difference -0.29, 95% CI -0.38 to -0.19; P<0.00001). An increase of the mean difference of MBL between the procedures was observed with the increase in the follow-up time (P=0.001) and with the increase of the mismatch between the implant platform and the abutment (P=0.001). Due to lack of satisfactory information, meta-analyses for the outcomes 'implant failure' and 'postoperative infection' were not performed. The results of the present review should be interpreted with caution due to the presence of uncontrolled confounding factors in the included studies, most of them with short follow-up periods. CLINICAL SIGNIFICANCE: The question whether platform-matched implants are more at risk for failure and loose more marginal bone than platform-switched implants has received increasing attention in the last years. As the philosophies of treatment alter over time, a periodic review of the different concepts is necessary to refine techniques and eliminate unnecessary procedures, forming a basis for optimum treatment.

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