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  • 1. Abrahamsson, Peter
    et al.
    Walivaara, Dan-Ake
    Anderud, Jonas
    Malmö högskola, Faculty of Odontology (OD).
    Jimbo, Ryo
    Malmö högskola, Faculty of Odontology (OD).
    Vertical bone augmentation with titanium granule blocks in rabbit calvaria2017In: Clinical and Experimental Dental Research, E-ISSN 2057-4347, Vol. 3, no 3, p. 100-106Article in journal (Refereed)
    Abstract [en]

    To determine whether it is possible to vertically augment bone utilizing a block graft from compressed titanium granules mainly used previously for contained bone defects and to determine whether there exists a difference in osteoconductive properties between the white and the grey granules. In 11 rabbits, 4 titanium blocks were inserted on each rabbit's skull bone according to a randomized scheme. These blocks were made from standardized compressed titanium granules. Type A: PTG grey, small granules (Pourus Titanium Granules, Tigran, Malmo, Sweden); Type B: PTG grey, large granules; Type C: PTG white, small granules; Type D: PTG white large granules. After 12 weeks, the animals were sacrificed and specimens were collected for histology and mu CT scanning. From both the mu CT and histology, it can be said that bone formation was successfully achieved for all groups, and the granules maintained their volume. The histomorphometric BA (bone area) evaluation in the entire grafted area presented that there were no statistical differences between all groups tested. The lowest 1/4 BA in contact with the rabbit skull presented that groups A and C presented the highest mean BA, and group A presented significantly higher BA than that of group D (p = 0,049). No significant differences were noted between groups A, B and C. Within the limitation of this study, no differences were noted between small white or grey PTG blocks. The large granules presented less bone ingrowth area compared to the small granules and this trend was regardless of the different PTG types. The entire grafted area was not filled with new bone suggesting that bone migration occurred mostly from the existing cortical bone side suggesting contact osteogenesis.

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  • 2.
    Alenezi, Ali
    et al.
    Malmö högskola, Faculty of Odontology (OD).
    Naito, Yoshihito
    Malmö högskola, Faculty of Odontology (OD).
    Andersson, Martin
    Chrcanovic, Bruno
    Malmö högskola, Faculty of Odontology (OD).
    Wennerberg, Ann
    Malmö högskola, Faculty of Odontology (OD).
    Jimbo, Ryo
    Malmö högskola, Faculty of Odontology (OD).
    Characteristics of 2 Different Commercially Available Implants with or without Nanotopography2013In: International Journal of Dentistry, ISSN 1687-8728, E-ISSN 1687-8736, Vol. 2013, no 769768, article id 769768Article in journal (Refereed)
    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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  • 3.
    Alenezi, Ali
    et al.
    Malmö högskola, Faculty of Odontology (OD). Malmö högskola, Biofilms Research Center for Biointerfaces.
    Naito, Yoshihito
    Malmö högskola, Faculty of Odontology (OD). Malmö högskola, Biofilms Research Center for Biointerfaces.
    Terukina, Takayuki
    Prananingrum, Widyasri
    Jinno, Yohei
    Malmö högskola, Faculty of Odontology (OD). Malmö högskola, Biofilms Research Center for Biointerfaces.
    Tagami, Tatsuaki
    Ozeki, Tetsuya
    Galli, Silvia
    Malmö högskola, Faculty of Odontology (OD). Malmö högskola, Biofilms Research Center for Biointerfaces.
    Jimbo, Ryo
    Malmö högskola, Faculty of Odontology (OD). Malmö högskola, Biofilms Research Center for Biointerfaces.
    Controlled release of Clarithromycin from PLGA microspheres enhances bone regeneration in rabbit calvaria defects2017In: Journal of Biomedical Materials Research. Part B - Applied biomaterials, ISSN 1552-4973, E-ISSN 1552-4981, Vol. 106, no 1, p. 201-208Article in journal (Refereed)
    Abstract [en]

    Purpose: To evaluate the controlled release effect of Clarithromycin loaded in PLGA microspheres in a rabbit calvaria defect model. Methods: Clarithromycin-loaded PLGA microspheres (MSPs) were formulated by modified O/W single emulsion/solvent evaporation method. After characterization, in vivo animal experiment was conducted. Four critical size bone defects were created in the calvaria of New Zealand White rabbits (n=21, n=7/time point). The bone defects were randomly designated to 4 groups: Group 1: No augmentation (sham), Group 2: beta-Tricalcium phosphate (β-TCP), Group 3: beta-Tricalcium phosphate (β-TCP) with 0.12 µg clarithromycin, and Group 4: beta-Tricalcium phosphate (β-TCP) with 6.12 µg PLGA microspheres (loaded with 0.12 µg clarithromycin). After 2, 4 and 12 weeks of healing, the levels of bone regeneration were evaluated using micro- computed tomography and histology. Results: The average size of the PLGA microspheres was 26.38 μm that showed 94% encapsulation efficacy with clarithromycin. Clarithromycin release from PLGA microspheres revealed sustained release for around 4 weeks with approximately 50% release of clarithromycin during the first week. In the histological analysis, new bone formation was evident at 2 and 4 weeks of healing in all groups and bone formation increased as a function of healing time in vivo. At 12 weeks, Group 4 showed significantly higher amount of newly formed bone compared to Group 1 (p=0,002). Moreover, during the micro CT exam, Group 4 expressed significantly higher bone formation compared to Group 1 at all time points tested (p=0.00, 0.014, and 0.002 in 2, 4, and 12 weeks, respectively). Conclusions: PLGA microspheres demonstrated initial burst release of clarithromycin followed by a sustained release profile. The in vivo findings showed that β-TCP with clarithromycin-loaded microspheres can enhance bone formation in bone defects.

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  • 4. Anchieta, Rodolfo B.
    et al.
    Baldassarri, Marta
    Guastaldi, Fernando
    Tovar, Nick
    Janal, Malvin N.
    Gottlow, Jan
    Dard, Michel
    Jimbo, Ryo
    Malmö högskola, Faculty of Odontology (OD).
    Coelho, Paulo G.
    Mechanical Property Assessment of Bone Healing around a Titanium-Zirconium Alloy Dental Implant2014In: Clinical Implant Dentistry and Related Research, ISSN 1523-0899, E-ISSN 1708-8208, Vol. 16, no 6, p. 913-919Article in journal (Refereed)
    Abstract [en]

    BackgroundIt has been reported that titanium-zirconium alloy with 13-17% zirconium (TiZr1317) implants show higher biomechanical stability and bone area percentage relative to commercially pure titanium (cpTi) grade 4 fixtures. PurposeThis study aimed to determine whether the higher stability for TiZr1317 implants is associated with higher mechanical properties of remodeling bone in the areas around the implants. Materials and MethodsThis study utilized 36 implants (n=18: TiZr1317, n=18: cpTi), which were placed in the healed ridges of the mandibular premolar and first molar of 12 mini pigs (n=3 implants/animal). After 4 weeks in vivo, the samples were retrieved, and resin-embedded histologic sections of approximately 100m in thickness were prepared. In order to determine the nanomechanical properties, nanoindentation (n=30 tests/specimen) was performed on the bone tissue of the sections under wet conditions with maximum load of 300N (loading rate: 60N/s). ResultsThe mean (standard deviation) elastic modulus (E) and hardness (H) for the TiZr1317 group were 2.73 +/- 0.50GPa and 0.116 +/- 0.017GPa, respectively. For the cpTi group, values were 2.68 +/- 0.51GPa and 0.110 +/- 0.017GPa for E and H, respectively. Although slightly higher mechanical properties values were observed for the TiZr1317 implants relative to the cpTi for both elastic modulus and hardness, these differences were not significant (E=p>0.75; H=p>0.59). ConclusionsThe titanium-zirconium alloy used in this study presented similar degrees of nanomechanical properties to that of the cpTi implants.

  • 5.
    Anderud, Jonas
    et al.
    Malmö högskola, Faculty of Odontology (OD).
    Abrahamsson, Peter
    Jimbo, Ryo
    Malmö högskola, Faculty of Odontology (OD).
    Isaksson, Sten
    Adolfsson, Erik
    Malmström, Johan
    Naito, Yoshihito
    Malmö högskola, Faculty of Odontology (OD).
    Wennerberg, Ann
    Malmö högskola, Faculty of Odontology (OD).
    Guided bone augmentation using ceramic space-maintaining devices: the impact of chemistry.2015In: Clinical, Cosmetic and Investigational Dentistry, E-ISSN 1179-1357, Vol. 7, p. 45-53Article in journal (Refereed)
    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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  • 6.
    Anderud, Jonas
    et al.
    Malmö högskola, Faculty of Odontology (OD).
    Jimbo, Ryo
    Malmö högskola, Faculty of Odontology (OD).
    Abrahamsson, Peter
    Adolfsson, Erik
    Malmström, Johan
    Wennerberg, Ann
    Malmö högskola, Faculty of Odontology (OD).
    The impact of surface roughness and permeability in hydroxyapatite bone regeneration membranes2016In: Clinical Oral Implants Research, ISSN 0905-7161, E-ISSN 1600-0501, Vol. 27, no 8, p. 1047-1054Article in journal (Refereed)
    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.

  • 7.
    Anderud, Jonas
    et al.
    Malmö högskola, Faculty of Odontology (OD).
    Jimbo, Ryo
    Malmö högskola, Faculty of Odontology (OD).
    Abrahamsson, Peter
    Isaksson, Sten G
    Adolfsson, Erik
    Malmstrom, Johan
    Kozai, Yusuke
    Hallmer, Fredrik
    Malmö högskola, Faculty of Odontology (OD).
    Wennerberg, Ann
    Malmö högskola, Faculty of Odontology (OD).
    Guided bone augmentation using a ceramic space-maintaining device2014In: Oral surgery, oral medicine, oral pathology and oral radiology, ISSN 2212-4403, E-ISSN 2212-4411, Vol. 118, no 5, p. 532-538Article in journal (Refereed)
    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.

  • 8. Baires-Campos, Felipe-Eduardo
    et al.
    Jimbo, Ryo
    Malmö högskola, Faculty of Odontology (OD).
    Bonfante, Estevam-Augusto
    Fonseca-Oliveira, Maiolino-Thomaz
    Moura, Camila
    Zanetta-Barbosa, Darceny
    Coelho, Paulo-Guilherme
    Drilling dimension effects in early stages of osseointegration and implant stability in a canine model2015In: Medicina Oral, ISSN 1698-4447, E-ISSN 1698-6946, Vol. 20, no 4, p. E471-E479Article in journal (Refereed)
    Abstract [en]

    Background: This study histologically evaluated two implant designs: a classic thread design versus another specifically designed for healing chamber formation placed with two drilling protocols. Material and Methods: Forty dental implants (4 1 mm diameter) with two different macrogeometries were inserted in the tibia of 10 Beagle dogs, and maximum insertion torque was recorded. Drilling techniques were: until 3.75 mm (regular-group); and until 4.0 mm diameter (overdrilling-group) for both implant designs. At 2 and 4 weeks, samples were retrieved and processed for histomorphometric analysis. For torque and BIC (bone-to-implant contact) and BAFO (bone area fraction occupied), a general-linear model was employed including instrumentation technique and time in vivo as independent. Results: The insertion torque recorded for each implant design and drilling group significantly decreased as a function of increasing drilling diameter for both implant designs (p<0.001). No significant differences were detected between implant designs for each drilling technique (p>0.18). A significant increase in BIC was observed from 2 to 4 weeks for both implants placed with the overdrilling technique (p<0.03) only, but not for those placed in the 3.75 mm drilling sites (p>0.32). Conclusions: Despite the differences between implant designs and drilling technique an intramembranous-like healing mode with newly formed woven bone prevailed.

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  • 9. Barkarmo, S.
    et al.
    Andersson, M.
    Currie, F.
    Kjellin, P.
    Jimbo, Ryo
    Malmö högskola, Faculty of Odontology (OD).
    Johansson, C. B.
    Stenport, V.
    Enhanced bone healing around nanohydroxyapatite-coated polyetheretherketone implants: An experimental study in rabbit bone2014In: Journal of biomaterials applications, ISSN 0885-3282, E-ISSN 1530-8022, Vol. 29, no 5, p. 737-747Article in journal (Refereed)
    Abstract [en]

    Objective: To investigate the bone response to threaded polyetheretherketone (PEEK) implants coated with nanohydroxyapatite. Materials and methods: A total of 39 PEEK implants were coated with nanocrystalline hydroxyapatite and 39 uncoated implants were used as controls. The implant surface was characterized by optical interferometry and scanning electron microscope. The implants were inserted in the tibia and femur of 13 rabbits. After 6 weeks of healing, quantitative and qualitative analyses were performed. Results: The test implants showed significantly higher removal torque test values compared with the control group. Histomorphometric evaluation demonstrated higher bone-to-implant contact for the test implants; however, there were no differences in bone area between the groups. Qualitative histological analyses demonstrated inflammatory cellular reactions in close vicinity of both implant surfaces. A two-cell layer of foreign body giant cells was observed irrespective of sample type. Conclusion: Our findings demonstrate that implants with a threaded design render good stability to PEEK in both coated and uncoated implants. Nanohydroxyapatite-coated PEEK implants demonstrated improved bone formation compared with uncoated controls.

  • 10. Bonfante, Estevam Augusto
    et al.
    Granato, Rodrigo
    Marin, Charles
    Jimbo, Ryo
    Malmö högskola, Faculty of Odontology (OD).
    Giro, Gabriela
    Suzuki, Marcelo
    Coelho, Paulo
    Biomechanical testing of microblasted, acid-etched/microblasted, anodized, and discrete crystalline deposition surfaces: an experimental study in beagle dogs2013In: International Journal of Oral & Maxillofacial Implants, ISSN 0882-2786, E-ISSN 1942-4434, Vol. 28, no 1, p. 136-142Article in journal (Refereed)
    Abstract [en]

    PURPOSE: Modifications in implant surface topography and chemistry may alter the early bone response at different levels. This study characterized four implant surfaces and evaluated the biomechanical fixation and histologic response at early implantation times in a canine radius model. MATERIALS AND METHODS: External-hexagon Branemark-type implants were used with four experimental surfaces: microblasted (MI), acid-etched and microblasted (AAM), anodized (A), and discrete crystalline deposition (DCD). Surface topography was assessed by scanning electron microscopy, interferometry, and x-ray photoelectron spectroscopy. The implants were placed in the central region of the radii of eight beagle dogs and remained in vivo for 10 or 30 days. The implants were torqued to interface failure, and a general linear statistical model with torque as the dependent variable and implant surface and time in vivo as independent variables was used. RESULTS: All surfaces presented were textured, and different surface chemistries were observed. No significant differences between implant surfaces were observed for torque at 10 days. However, at 30 days, the AAM surface presented significantly higher torque values compared to the DCD and A surfaces. Significantly higher torque values were observed at 30 days compared to 10 days (P < .001). CONCLUSIONS: Significantly different biomechanical fixation dependent on surface preparation was observed after 30 days, and all surfaces were biocompatible and osteoconductive.

  • 11.
    Bougas, Kostas
    et al.
    Malmö högskola, Faculty of Odontology (OD).
    Jimbo, Ryo
    Malmö högskola, Faculty of Odontology (OD).
    Vandeweghe, Stefan
    Malmö högskola, Faculty of Odontology (OD).
    Hayashi, Mariko
    Malmö högskola, Faculty of Odontology (OD).
    Bryington, Matthew
    Malmö högskola, Faculty of Odontology (OD).
    Kozai, Yusuke
    Schwartz-Filho, Humberto O
    Tovar, Nick
    Adolfsson, Erik
    Ono, Daisuke
    Coelho, Paulo G
    Wennerberg, Ann
    Malmö högskola, Faculty of Odontology (OD).
    Bone apposition to laminin-1 coated implants: histologic and 3D evaluation2013In: International Journal of Oral and Maxillofacial Surgery, ISSN 0901-5027, E-ISSN 1399-0020, Vol. 42, no 5, p. 677-682Article in journal (Refereed)
    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.

  • 12.
    Bougas, Kostas
    et al.
    Malmö högskola, Faculty of Odontology (OD).
    Jimbo, Ryo
    Malmö högskola, Faculty of Odontology (OD).
    Xue, Ying
    Mustafa, Kamal
    Wennerberg, Ann
    Malmö högskola, Faculty of Odontology (OD).
    Novel implant coating agent promotes gene expression of osteogenic markers in rats during early osseointegration2012In: International Journal of Biomaterials, ISSN 1687-8787, E-ISSN 1687-8795, Vol. 2012, article id 579274Article in journal (Refereed)
    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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  • 13.
    Braian, Michael
    et al.
    Malmö högskola, Faculty of Odontology (OD).
    Jimbo, Ryo
    Malmö högskola, Faculty of Odontology (OD).
    Wennerberg, Ann
    Malmö högskola, Faculty of Odontology (OD).
    Production tolerance of additive manufactured polymeric objects for clinical applications2016In: Dental Materials, ISSN 0109-5641, E-ISSN 1879-0097, Vol. 32, no 7, p. 853-861Article in journal (Refereed)
    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

  • 14. Breding, Karin
    et al.
    Jimbo, Ryo
    Malmö högskola, Faculty of Odontology (OD).
    Hayashi, Mariko
    Malmö högskola, Faculty of Odontology (OD).
    Xue, Ying
    Mustafa, Kamal
    Andersson, Martin
    The effect of hydroxyapatite nanocrystals on osseointegration of titanium implants: an in vivo rabbit study2014In: International Journal of Dentistry, ISSN 1687-8728, E-ISSN 1687-8736, Vol. 2014, article id 171305Article in journal (Refereed)
    Abstract [en]

    Osseointegration is dependent on implant surface characteristics, including surface chemistry and topography. The presence of nanosized calcium phosphates on the implant surface is interesting to investigate since they affect both the nanotopography and surface chemistry, forming a bone mineral resembling surface. In this work, the osseointegration of titanium implants with and without the presence of hydroxyapatite (HA) nanocrystals has been evaluated in vivo. The integration was examined using removal torque measurements and real-time polymerase chain reaction (RT-PCR) analysis. The study was performed using two healing time points, 3 and 12 weeks. The results showed that the torque needed to remove the implants was insignificant between the non- and HA-coated implants, both at weeks 3 and 12. The RT-PCR, however, showed significant differences for osteoblast, osteoclast, and proinflammation markers when HA nanocrystals were present.

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  • 15. Bressan, Eriberto
    et al.
    Stocchero, Michele
    Malmö högskola, Faculty of Odontology (OD).
    Jimbo, Ryo
    Malmö högskola, Faculty of Odontology (OD).
    Rosati, Claudio
    Fanti, Elena
    Tomasi, Cristiano
    Lops, Diego
    Microbial Leakage at Morse Taper Conometric Prosthetic Connection: An In Vitro Investigation2017In: Implant Dentistry, ISSN 1056-6163, E-ISSN 1538-2982, Vol. 26, no 5, p. 756-761Article in journal (Refereed)
    Abstract [en]

    OBJECTIVE: To evaluate in vitro the sealing capability at the prosthetic connection interface of 2 conometric systems. MATERIALS AND METHODS: Two conometric systems with the same design and different material were used, for a total of 24 samples. Each sample was assembled by a tapered abutment and respective coping. In group A, the copings were made of gold, whereas in group B they were made of PEEK. Three μL of mix bacterial suspension (Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, and Fusobacterium nucleatum species) was inoculated into the abutment screw hole, and the coping was inserted on the abutment. Samples were immersed into culture tubes and incubated for 24, 48, and 72 hours into anaerobic conditions. Visual evaluation of turbidity was performed at each time point. Qualitative-quantitative assessment using real-time polymerase chain reaction was performed at 72 hours. Any difference between the groups was checked by means of Fisher exact test. RESULTS: Microbial leakage occurred in both groups, and there was no statistically significant difference between groups. Microbial concentration resulted in a presence inferior to 1 × 10 copies/μL in all positive assemblies. CONCLUSIONS: Because of the low bacterial count, it can be concluded that a minimal bacterial infiltration may be allowed by conometric interfaces for prosthetic connection.

  • 16. Browaeys, Hilde
    et al.
    Vandeweghe, Stefan
    Malmö högskola, Faculty of Odontology (OD).
    Johansson, Carina B.
    Jimbo, Ryo
    Malmö högskola, Faculty of Odontology (OD).
    Deschepper, Ellen
    de Bruyn, Hugo
    Malmö högskola, Faculty of Odontology (OD).
    The histological evaluation of osseointegration of surface enhanced microimplants immediately loaded in conjunction with sinuslifting in humans2013In: Clinical Oral Implants Research, ISSN 0905-7161, E-ISSN 1600-0501, Vol. 24, no 1, p. 36-44Article in journal (Refereed)
    Abstract [en]

    OBJECTIVE: The aim was to investigate histomorphometrically whether or not implant surface nanotopography improves the bone response under immediate loading simultaneous to sinus grafting. MATERIALS AND METHODS: Dual acid-etched titanium microimplants with/without crystalline surface deposition of calcium phosphate particles were placed in bilateral sinuslift areas grafted with a mixture of iliac crest bone and BioOss. Surface topography of microimplants was characterized using interferometry. Loaded microimplants (MsL) were immobilized in a provisional bridge supported by four normal size implants. Some patients had unloaded microimplants as controls (MsU). Biopsies were trephined after 2 or 4 months and histomorphometric analysis of bone area (BA) and bone-to-implant contact (BC) was performed. Nonparametric methods for dependent data were used to compare effect of surface modification, and healing time (2 vs. 4 months). RESULTS: A total of 53 biopsies were available from 13 patients. A total of 4/28 and 1/11 MsL failed after resp. 2 and 4 months vs. 0/6 and 1/5 MsU. Many loaded biopsies were damaged at the apical portion and showed no bone adhesion. MsL decreased in BA from coronal to apical from 2 to 4 months; Coronal > Middle (P = 0.047), Coronal > Apical (P < 0.001) and Middle > Apical (P < 0.001). This gradual decrease was not observed for BC; Coronal < Middle and Middle > Apical (P < 0.001). Only the middle part showed significant bone contact after 2 months. For MsL there was no statistically significant difference between surface or time indicating that improvement of osseointegration over time due to maturation of the graft was poor. The MsU did not show any difference between Osseotite and Nanotite for BIC and BA (P > 0.05) but doubled both their BA and BIC (P < 0.05) between 2 and 4 months. CONCLUSIONS: Osseointegration in sinus-grafted bone mixed with BioOss was poor irrespective of healing time or nanotopographical surface modification. The apex of MsL showed minimal bone contact suggesting that the graft does not add to the loading capacity. Surface enhancement was not beneficial despite the enlarged surface area. Overloading, most critical coronally of an implant, increases risks for implant failure and jeopardizes bone healing especially under immediate loading conditions with high load.

  • 17. Bryington, Matthew S
    et al.
    Hayashi, Mariko
    Malmö högskola, Faculty of Odontology (OD).
    Kozai, Yusuke
    Andersson, Martin
    Vandeweghe, Stefan
    Wennerberg, Ann
    Malmö högskola, Faculty of Odontology (OD).
    Jimbo, Ryo
    Malmö högskola, Faculty of Odontology (OD).
    The influence of nano hydroxyapatite coating on osseointegration after extended healing periods2013In: Dental Materials, ISSN 0109-5641, E-ISSN 1879-0097, Vol. 29, no 5, p. 514-520Article in journal (Refereed)
    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.

  • 18. Campos, Felipe E. B.
    et al.
    Jimbo, Ryo
    Malmö högskola, Faculty of Odontology (OD).
    Bonfante, Estevam A.
    Barbosa, Darceny Z.
    Oliveira, Maiolino T. F.
    Janal, Malvin N.
    Coelho, Paulo G.
    Are insertion torque and early osseointegration proportional?: A histologicevaluation2015In: Clinical Oral Implants Research, ISSN 0905-7161, E-ISSN 1600-0501, Vol. 26, no 11, p. 1256-1260Article in journal (Refereed)
    Abstract [en]

    ObjectivesThe objective of this histologic study was to determine the effect of three drilling protocols (oversized, intermediate, and undersized) on biologic responses to a single implant type at early healing periods (2weeks in vivo) in a beagle dog model. Materials and methodsTen beagle dogs were acquired and subjected to surgeries in the tibia 2weeks before euthanasia. During surgery, each dog received three Unitite implants, 4mm in diameter by 10mm in length, in bone sites drilled to 3.5, 3.75, and 4.0mm in final diameter. The insertion torque was recorded during surgery, and bone-to-implant contact (BIC), and bone area fraction occupied (BAFO) measured from the histology. Each outcome measure was compared between treatment conditions with the Wilcoxon signed-rank test. Bonferroni-corrected statistical significance was set to 95%. ResultsInsertion torque increased as an inverse function of drilling diameter, as indicated by significant differences in torque levels between each pair of conditions (P=0.005). BIC and BAFO levels were highest and statistically similar in the recommended and undersized conditions and significantly reduced in the oversized condition (P<0.01). ConclusionsReduced drilling dimensions resulted in increased insertion torque (primary stability). While BIC and BAFO were maximized when drilling the recommended diameter hole, only the oversized hole resulted in evidence of statistically reduced integration.

  • 19.
    Cecchinato, Francesca
    et al.
    Malmö högskola, Faculty of Odontology (OD).
    Agha, Nezha Ahmad
    Martinez-Sanchez, Adela Helvia
    Luthringer, Berengere Julie Christine
    Feyerabend, Frank
    Willumeit-Roemer, Regine
    Jimbo, Ryo
    Malmö högskola, Faculty of Odontology (OD).
    Wennerberg, Ann
    Malmö högskola, Faculty of Odontology (OD).
    Influence of Magnesium Alloy Degradation on Undifferentiated Human Cells2015In: PLOS ONE, E-ISSN 1932-6203, Vol. 10, no 11, article id e0142117Article in journal (Refereed)
    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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  • 20.
    Cecchinato, Francesca
    et al.
    Malmö högskola, Faculty of Odontology (OD).
    Atefyekta, Saba
    Wennerberg, Ann
    Malmö högskola, Faculty of Odontology (OD).
    Andersson, Martin
    Jimbo, Ryo
    Malmö högskola, Faculty of Odontology (OD).
    Davies, Julia R
    Malmö högskola, Faculty of Odontology (OD).
    Modulation of the nanometer pore size improves magnesium adsorption into mesoporous titania coatings and promotes bone morphogenic protein 4 expression in adhering osteoblasts2016In: Dental Materials, ISSN 0109-5641, E-ISSN 1879-0097, Vol. 32, no 7, p. E148-E158Article in journal (Refereed)
    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

  • 21.
    Cecchinato, Francesca
    et al.
    Malmö högskola, Faculty of Odontology (OD). Malmö högskola, Biofilms Research Center for Biointerfaces.
    Karlsson, Johan
    Ferroni, Letizia
    Gardin, Chiara
    Galli, Silvia
    Malmö högskola, Faculty of Odontology (OD). Malmö högskola, Biofilms Research Center for Biointerfaces.
    Wennerberg, Ann
    Malmö högskola, Faculty of Odontology (OD). Malmö högskola, Biofilms Research Center for Biointerfaces.
    Zavan, Barbara
    Andersson, Martin
    Jimbo, Ryo
    Malmö högskola, Faculty of Odontology (OD). Malmö högskola, Biofilms Research Center for Biointerfaces.
    Osteogenic potential of human adipose-derived stromal cells on 3-dimensional mesoporous TiO2 coating with magnesium impregnation2015In: Materials science & engineering. C, biomimetic materials, sensors and systems, ISSN 0928-4931, E-ISSN 1873-0191, Vol. 52, p. 225-234Article in journal (Refereed)
    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.

  • 22.
    Cecchinato, Francesca
    et al.
    Malmö högskola, Faculty of Odontology (OD).
    Xue, Ying
    Karlsson, Johan
    He, Wenxiao
    Mustafa, Kamal
    Andersson, Martin
    Wennerberg, Ann
    Malmö högskola, Faculty of Odontology (OD).
    Jimbo, Ryo
    Malmö högskola, Faculty of Odontology (OD).
    In vitro evaluation of human fetal osteoblast response to magnesium loaded mesoporous TiO2 coating2014In: Journal of Biomedical Materials Research. Part A, ISSN 1549-3296, E-ISSN 1552-4965, Vol. 102, no 11, p. 3862-3871Article in journal (Refereed)
    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.

  • 23.
    Chowdhary, Ramesh
    et al.
    Malmö högskola, Faculty of Odontology (OD).
    Halldin, Anders
    Malmö högskola, Faculty of Odontology (OD).
    Jimbo, Ryo
    Malmö högskola, Faculty of Odontology (OD).
    Wennerberg, Ann
    Malmö högskola, Faculty of Odontology (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 study2013In: Implant Dentistry, ISSN 1056-6163, E-ISSN 1538-2982, Vol. 22, no 1, p. 91-96Article in journal (Refereed)
    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.

  • 24.
    Chowdhary, Ramesh
    et al.
    Malmö högskola, Faculty of Odontology (OD).
    Halldin, Anders
    Malmö högskola, Faculty of Odontology (OD).
    Jimbo, Ryo
    Malmö högskola, Faculty of Odontology (OD).
    Wennerberg, Ann
    Malmö högskola, Faculty of Odontology (OD).
    Influence of Micro Threads Alteration on Osseointegration and Primary Stability of Implants: An FEA and In Vivo Analysis in Rabbits2015In: Clinical Implant Dentistry and Related Research, ISSN 1523-0899, E-ISSN 1708-8208, Vol. 17, no 3, p. 562-569Article in journal (Refereed)
    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.

  • 25.
    Chowdhary, Ramesh
    et al.
    Malmö högskola, Faculty of Odontology (OD).
    Jimbo, Ryo
    Malmö högskola, Faculty of Odontology (OD).
    Thomsen, C S
    Carlsson, L
    Wennerberg, Ann
    Malmö högskola, Faculty of Odontology (OD).
    The osseointegration stimulatory effect of macrogeometry-modified implants: a study in the rabbit2014In: Clinical Oral Implants Research, ISSN 0905-7161, E-ISSN 1600-0501, Vol. 25, no 9, p. 1051-5Article in journal (Refereed)
    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.

  • 26.
    Chowdhary, Ramesh
    et al.
    Malmö högskola, Faculty of Odontology (OD).
    Jimbo, Ryo
    Malmö högskola, Faculty of Odontology (OD).
    Thomsen, Christian
    Carlsson, Lennart
    Wennerberg, Ann
    Malmö högskola, Faculty of Odontology (OD).
    Biomechanical evaluation of macro and micro designed screw-type implants: an insertion torque and removal torque study in rabbits2013In: Clinical Oral Implants Research, ISSN 0905-7161, E-ISSN 1600-0501, Vol. 24, no 3, p. 342-346Article in journal (Refereed)
    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.

  • 27.
    Coelho, Paulo G.
    et al.
    Department of Biomaterials and Biomimetics, Hansjörg Wyss Department of Plastic Surgery, NYU College of Dentistry, NYU Langone Medical Center, 433 1st ave room 844, New York, NY, 10010, USA.
    Bonfante, Estevam A.
    Department of Prosthodontics and Periodontology, Bauru School of Dentistry – University of São Paulo, Al. Otavio Pinheiro Brisola 9-75, Bauru, SP, Brazil, 17.012-901.
    Jimbo, Ryo
    Malmö högskola, Faculty of Odontology (OD).
    Revisiting the Role of Implant Design and Surgical Instrumentation on Osseointegration2017In: Implant Aesthetics: Keys to Diagnosis and Treatment / [ed] Edward Dwayne Karateew, Springer, 2017, p. 43-56Chapter in book (Refereed)
    Abstract [en]

    Osseointegration of metallic devices has shown to be successful in several biomedical fields. Despite the high success rates, continuous efforts to reduce osseointegration time have been marked by investigations considering a limited number of variables. Recent research has pointed that the interplay between surgical instrumentation and device macrogeometry not only plays a key role on both early and delayed stages of osseointegration but may also be key in how efficient smaller length scale designing (at the micro- and nanogeometrical levels) may be in hastening early stages of osseointegration. The present chapter focuses on how the different metallic device design length scales’ interplay (macro, micro, and nano) affects the bone response and how its understanding may affect the next generation of metallic device designing for osseointegration.

  • 28. Coelho, Paulo G.
    et al.
    Gil, Luiz F
    Neiva, Rodrigo
    Jimbo, Ryo
    Malmö högskola, Faculty of Odontology (OD).
    Tovar, Nick
    Lilin, Thomas
    Bonfante, Estevam A.
    Microrobotized blasting improves the bone-to-textured implant response. A preclinical in vivo biomechanical study2016In: Journal of The Mechanical Behavior of Biomedical Materials, ISSN 1751-6161, E-ISSN 1878-0180, Vol. 56, p. 175-182Article in journal (Refereed)
    Abstract [en]

    This study evaluated the effect of microrobotized blasting of titanium endosteal implants relative to their manually blasted counterparts. Two different implant systems were utilized presenting two different implant surfaces. Control surfaces (Manual) were fabricated by manually grit blasting the implant surfaces while experimental surfaces (Microblasted) were fabricated through a microrobotized system that provided a one pass grit blasting routine. Both surfaces were created with the same similar to 50 gm average particle size alumina powder at similar to 310 KPa. Surfaces were then etched with 37% HCl for 20 min, washed, and packaged through standard industry procedures. The surfaces were characterized through scanning electron microscopy (SEM) and optical interferometry, and were then placed in a beagle dog radius model remaining in vivo for 3 and 6 weeks. The implant removal torque was recorded and statistical analysis evaluated implant system and surface type torque levels as a function of time in vivo. Histologic sections were qualitatively evaluated for tissue response. Electron microscopy depicted textured surfaces for both manual and microblasted surfaces. Optical interferometry showed significantly higher S-a, S-q, values for the microblasted surface and no significant difference for S-ds and S-dr values between surfaces. In vivo results depicted that statistically significant gains in biomechanical fixation were obtained for both implant systems tested at 6 weeks in vivo, while only one system presented significant biomechanical gain at 3 weeks. Histologic sections showed qualitative higher amounts of new bone forming around microblasted implants relative to the manually blasted group. Microrobotized blasting resulted in higher biomechanical fixation of endosteal dental implants and should be considered as an alternative for impant surface manufacturing.

  • 29. Coelho, Paulo G
    et al.
    Granato, Rodrigo
    Marin, Charles
    Jimbo, Ryo
    Malmö högskola, Faculty of Odontology (OD).
    Lin, Siyan
    Witek, Lukasz
    Suzuki, Marcel
    Bonfante, Estevam Augusto
    Effect of Si addition on Ca- and P-impregnated implant surfaces with nanometer-scale roughness: an experimental study in dogs2012In: Clinical Oral Implants Research, ISSN 0905-7161, E-ISSN 1600-0501, Vol. 23, no 3, p. 373-378Article in journal (Refereed)
    Abstract [en]

    OBJECTIVES: To investigate the effect of Si addition on a nanometer-scale roughness Ca and P implant surfaces in a canine tibia model by biomechanical and histomorphometric evaluations. MATERIAL AND METHODS: The implant surfaces comprised a resorbable media CaP microblasted (control) and a CaP resorbable media+silica-boost microblasted (experimental) surfaces. Surfaces were characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and optical interferometry (IFM) down to the nanometric level. The animal model involved the bilateral placement of control (n=24) and experimental surface (n=24) implants along the proximal tibiae of six dogs, remaining in vivo for 2 or 4 weeks. After euthanization, half of the specimens were torqued-to-interface failure, and the other half was subjected to histomorphologic and bone-to-implant contact (BIC) evaluation. Torque and BIC statistical evaluation was performed by the Friedman test at 95% level of significance, and comparisons between groups was performed by the Dunn test. RESULTS: IFM and SEM observations depicted comparable roughness parameters for both implant surfaces on the micrometer and nanometer scales. XPS analysis revealed similar chemical composition, except for the addition of Si on the experimental group. Torque-to-interface failure and BIC mean values showed no significant differences (P=0.25 and 0.51, respectively) at both 2- and 4-week evaluation points for experimental and control groups. Early bone healing histomorphologic events were similar between groups. CONCLUSIONS: The experimental surface resulted in not significantly different biomechanical fixation and BIC relative to control. Both surfaces were biocompatible and osseoconductive.

  • 30. Coelho, Paulo G.
    et al.
    Jimbo, Ryo
    Malmö högskola, Faculty of Odontology (OD).
    Osseointegration of metallic devices: Current trends based on implant hardware design2014In: Archives of Biochemistry and Biophysics, ISSN 0003-9861, E-ISSN 1096-0384, Vol. 561, p. 99-108Article, review/survey (Refereed)
    Abstract [en]

    Osseointegration of metallic devices has been one of the most successful treatments in rehabilitative dentistry and medicine over the past five decades. While highly successful, the quest for designing surgical instrumentation and associated implantable devices that hastens osseointegration has been perpetual and has often been approached as single variable preclinical investigations. The present manuscript presents how the interplay between surgical instrumentation and device macrogeometry not only plays a key role on both early and delayed stages of osseointegration, but may also be key in how efficient smaller length scale designing (at the micrometer and nanometer scale levels) may be in hastening early stages of osseointegration. (C) 2014 Elsevier Inc. All rights reserved.

  • 31. Coelho, Paulo G.
    et al.
    Jimbo, Ryo
    Malmö högskola, Faculty of Odontology (OD).
    Tovar, Nick
    Bonfante, Estevam A.
    Osseointegration: hierarchical designing encompassing the macrometer, micrometer, and nanometer length scales2015In: Dental Materials, ISSN 0109-5641, E-ISSN 1879-0097, Vol. 31, no 1, p. 37-52Article in journal (Refereed)
    Abstract [en]

    Objective. Osseointegration has been a proven concept in implant dentistry and orthopedics for decades. Substantial efforts for engineering implants for reduced treatment time frames have focused on micrometer and most recently on nanometer length scale alterations with negligible attention devoted to the effect of both macrometer design alterations and surgical instrumentation on osseointegration. This manuscript revisits osseointegration addressing the individual and combined role of alterations on the macrometer, micrometer, and nanometer length scales on the basis of cell culture, preclinical in vivo studies, and clinical evidence. Methods. A critical appraisal of the literature was performed regarding the impact of dental implant designing on osseointegration. Results from studies with different methodological approaches and the commonly observed inconsistencies are discussed. Results. It is a consensus that implant surface topographical and chemical alterations can hasten osseointegration. However, the tailored combination between multiple length scale design parameters that provides maximal host response is yet to be determined. Signcance. In spite of the overabundant literature on osseointegration, a proportional inconsistency in findings hitherto encountered warrants a call for appropriate multivariable study designing to ensure that adequate data collection will enable osseointegration maximization and/or optimization, which will possibly lead to the engineering of endosteal implant designs that can be immediately placed/loaded regardless of patient dependent conditions.

  • 32. Coelho, Paulo G.
    et al.
    Suzuki, Marcelo
    Marin, Charles
    Granato, Rodrigo
    Gil, Luis F.
    Tovar, Nick
    Jimbo, Ryo
    Malmö högskola, Faculty of Odontology (OD).
    Neiva, Rodrigo
    Bonfante, Estevam A.
    Osseointegration of Plateau Root Form Implants: Unique Healing Pathway Leading to Haversian-Like Long-Term Morphology2015In: Engineering Mineralized and Load Bearing Tissue / [ed] Luiz E. Bertassoni, Paulo G. Coelho, Springer, 2015, p. 111-128Chapter in book (Other academic)
    Abstract [en]

    Endosteal dental implants have been utilized as anchors for dental and orthopedic rehabilitations for decades with one of the highest treatment success rates in medicine. Such success is due to the phenomenon of osseointegration where after the implant surgical placement, bone healing results into an intimate contact between bone and implant surface. While osseointegration is an established phenomenon, the route which osseointegration occurs around endosteal implants is related to various implant design factors including surgical instrumentation and implant macro, micro, and nanometer scale geometry. In an implant system where void spaces (healing chambers) are present between the implant and bone immediately after placement, its inherent bone healing pathway results in unique opportunities to accelerate the osseointegration phenomenon at the short-term and its maintenance on the long-term through a haversian-like bone morphology and mechanical properties.

  • 33. Coelho, Paulo G.
    et al.
    Takayama, Tadahiro
    Yoo, Daniel
    Jimbo, Ryo
    Malmö högskola, Faculty of Odontology (OD).
    Karunagaran, Sanjay
    Tovar, Nick
    Janal, Malvin N.
    Yamano, Seiichi
    Nanometer-scale features on micrometer-scale surface texturing: A bone histological, gene expression, and nanomechanical study2014In: Bone, ISSN 8756-3282, E-ISSN 1873-2763, Vol. 65, p. 25-32Article in journal (Refereed)
    Abstract [en]

    Micro- and nanoscale surface modifications have been the focus of multiple studies in the pursuit of accelerating bone apposition or osseointegration at the implant surface. Here, we evaluated histological and nanomechanical properties, and gene expression, for a microblasted surface presenting nanometer-scale texture within a micrometer-scale texture (MB) (Ossean (TM) Surface, Intra-Lock International, Boca Raton, FL) versus a dual-acid etched surface presenting texture at the micrometer-scale only (AA), in a rodent femur model for 1, 2, 4, and 8 weeks in vivo. Following animal sacrifice, samples were evaluated in terms of histomorphometry, biomechanical properties through nanoindentation, and gene expression by real-time quantitative reverse transcription polymerase chain reaction analysis. Although the histomorphometric, and gene expression analysis results were not significantly different between MB and AA at 4 and 8 weeks, significant differences were seen at 1 and 2 weeks. The expression of the genes encoding collagen type I (COL-1), and osteopontin (OPN) was significantly higher for MB than for AA at 1 week, indicating up-regulated osteoprogenitor and osteoblast differentiation. At 2 weeks, significantly up-regulated expression of the genes for COL-1, runt-related transcription factor 2 (RUNX-2), osterix, and osteocalcin (OCN) indicated progressive mineralization in newly formed bone. The nanomechanical properties tested by the nanoindentation presented significantly higher-rank hardness and elastic modulus for the MB compared to AA at all time points tested. In conclusion, the nanotopographical featured surfaces presented an overall higher host-to-implant response compared to the microtextured only surfaces. The statistical differences observed in some of the osteogenic gene expression between the two groups may shed some insight into the role of surface texture and its extent in the observed bone healing mechanisms. (C) 2014 Elsevier Inc. All rights reserved.

  • 34. Coelho, Paulo G.
    et al.
    Teixeira, Hellen S.
    Marin, Charles
    Witek, Lukasz
    Tovar, Nick
    Janal, Malvin N.
    Jimbo, Ryo
    Malmö högskola, Faculty of Odontology (OD).
    The in vivo effect of P-15 coating on early osseointegration2014In: Journal of Biomedical Materials Research. Part B - Applied biomaterials, ISSN 1552-4973, E-ISSN 1552-4981, Vol. 102, no 3, p. 430-440Article in journal (Refereed)
    Abstract [en]

    The aim of this study was to evaluate mechanically and morphologically the effect of a specific peptide sequence P-15, when incorporated into implant surfaces. Three types of implants were used for the study: Group A: commercially pure titanium implant (blasted and acid etched) + electrochemical thin calcium phosphate deposition, Group B: commercially pure titanium implant (blasted and acid etched) + electrochemical thin calcium phosphate deposition + P-15 incorporation, and as control, Group C: commercially pure titanium implant (blasted and acid etched). After a topographical characterization, transcortical osteotomies were made, and all implant groups (102 implants per group) were randomly placed bilaterally in the tibiae of adult beagle dogs (n = 24). At, 1, 2, and 4 weeks post-surgery, the animals were sacrificed and the samples were retrieved for removal torque tests, for nano indentation, and for histomorphometrical analysis. The results (mean +/- 95% CI) showed that Group B (34.4 +/- 8.7%) presented statistically higher bone-to-implant contact than the other groups (A = 23.9 +/- 7.8%; C = 21.7 +/- 8.3%) at 1 week, indicating an enhanced osteogenesis due to the peptide incorporation. The results suggested that the incorporation of P-15 to implant surfaces increased its bioactivity and the effects were notable especially in the early stages of the healing process. (c) 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 102B: 430-440, 2014.

  • 35. Coelho, Paulo G.
    et al.
    Zavanelli, Ricardo A
    Salles, Marcos B
    Yeniyol, Sinem
    Tovar, Nick
    Jimbo, Ryo
    Malmö högskola, Faculty of Odontology (OD).
    Enhanced Bone Bonding to Nanotextured Implant Surfaces at a Short Healing Period: A Biomechanical Tensile Testing in the Rat Femur2016In: Implant Dentistry, ISSN 1056-6163, E-ISSN 1538-2982, Vol. 25, no 3, p. 322-327Article in journal (Refereed)
    Abstract [en]

    Purpose: To compare the bone bonding capabilities of 2 different surface treatments at an early healing period. Titanium alloy (Ti6Al4V) custom-made rectangular plates (1.4 x 2.4 x 4 mm) were either dual acid etched (Ti6Al4V-DAE) or nanotextured proprietary processed Ti6Al4V-Ossean (intraLock International, Boca Raton, FL). Materials and Methods: Implants were placed in the distal femurs of 10 Wistar rats and were allowed to heal for 9 days. After euthanasia, the bone immediately proximal and distal to the implant was removed to test the bone bonding force with a universal testing machine. Ultrastructure of the bone/implant interface was assessed by scanning electron microscopy Results: Ti6Al4V-NTB samples exhibited significantly greater bond strength than Ti6Al4V-DAE samples. Morphologically, the Ti6Al4V-Ossean surfaces presented intimate interaction with bone, whereas little interaction between the Ti6Al4V-DAE surface and bone was observed Conclusion: The results of this study indicated a significant increase in bone bonding for the Ossean surface, which is suggested to be the outcome of the nanotexturing.

  • 36. Cuellar, Jason M.
    et al.
    Yoo, Andrew
    Tovar, Nick
    Coelho, Paulo G.
    Jimbo, Ryo
    Malmö högskola, Faculty of Odontology (OD).
    Vandeweghe, Stefan
    Kirsch, Thorsten
    Quirno, Martin
    Errico, Thomas J.
    The Effects of Amicar and TXA on Lumbar Spine Fusion in an Animal Model2014In: Spine, ISSN 0362-2436, E-ISSN 1528-1159, Vol. 39, no 19, p. E1132-E1137Article in journal (Refereed)
    Abstract [en]

    Study Design. Animal model. Objective. To determine whether aminocaproic acid (Amicar) and tranexamic acid (TXA) inhibit spine fusion volume. Summary of Background Data. Amicar and TXA are antifibrinolytics used to reduce perioperative bleeding. Prior in vitro data showed that antifibrinolytics reduce osteoblast bone mineralization. This study tested whether antifibrinolytics Amicar and TXA inhibit spine fusion. Methods. Posterolateral L4-L6 fusion was performed in 50 mice, randomized into groups of 10, which received the following treatment before and after surgery: (1) saline; (2) TXA 100 mg/kg; (3) TXA 1000 mg/kg; (4) Amicar 100 mg/kg; and (5) Amicar 1000 mg/kg. High-resolution plane radiography was performed after 5 weeks and micro-CT (computed tomography) was performed at the end of the 12-week study. Radiographs were graded using the Lenke scale. Micro-CT was used to quantify fusion mass bone volume. One-way analysis of variance by ranks with Kruskal-Wallis testing was used to compare the radiographical scores. One-way analysis of variance with least significant difference post hoc testing was used to compare the micro-CT bone volume. Results. The average +/- standard deviation bone volume/total volume (%) measured in the saline, TXA 100 mg/kg, TXA 1000 mg/kg, Amicar 100 mg/kg, and Amicar 1000 mg/kg groups were 10.8 +/- 2.3%, 9.7 +/- 2.2%, 13.4 +/- 3.2%, 15.5 +/- 5.2%, and 17.9 +/- 3.5%, respectively. There was a significant difference in the Amicar 100 mg/kg (P < 0.05) and Amicar 1000 mg/kg (P < 0.001) groups compared with the saline group. There was greater bone volume in the Amicar groups compared with the TXA group (P < 0.001). There was more bone volume in the TXA 1000 mg/kg group compared with TXA 100 mg/kg (P < 0.05) but the bone volume in neither of the TXA groups was different to saline (P = 0.49). There were no between-group differences observed using plane radiographical scoring. Conclusion. Amicar significantly "enhanced" the fusion bone mass in a dose-dependent manner, whereas TXA did not have a significant effect on fusion compared with saline control. These data are in contrast to prior in vitro data that antifibrinolytics inhibit osteoblast bone mineralization.

  • 37. De Wilde, Elisabeth A. W. J.
    et al.
    Jimbo, Ryo
    Malmö högskola, Faculty of Odontology (OD).
    Wennerberg, Ann
    Malmö högskola, Faculty of Odontology (OD).
    Naito, Yoshihito
    Malmö högskola, Faculty of Odontology (OD).
    Coucke, Paul
    Bryington, Matthew S.
    Vandeweghe, Stefan
    De Bruyn, Hugo
    Malmö högskola, Faculty of Odontology (OD).
    The soft tissue immunologic response to hydroxyapatite-coated transmucosal implant surfaces: a study in humans2015In: Clinical Implant Dentistry and Related Research, ISSN 1523-0899, E-ISSN 1708-8208, Vol. 17, no S1, p. e65-e74Article in journal (Refereed)
    Abstract [en]

    ObjectiveTo evaluate the soft tissue response in humans immunologically and histologically after placement of mini-implants coated with or without nano-size hydroxyapatite coatings. Material and MethodsCommercially pure (cp) titanium mini-implants (n=13) or nano-hydroxyapatite-coated ones (n=12) were randomly placed into partially edentulous jaws. Crevicular fluid was sampled 1week after placement and subjected to quantitative polymerase chain reaction analysis to explore the inflammatory markers. After 8weeks, implants and surrounding soft and hard tissue were trephined, and undecalcified ground sections were prepared. Inflammatory cell accumulation within a defined region of interest in the soft tissue was quantified histomorphometrically. ResultsNo statistically significant differences in immunological response to the different implant surfaces were found for IL-6 (p=.438), TGF-2 (p=.467), MMP-8 (p=.758), CCL-3 (p=.758), IL-8 (p=.771), and IL-1 (0.771). Histomorphometric evaluation presented no statistically significant difference between the two mini-implant surfaces with regards to number of inflammatory cells (p=.669). ConclusionNano-hydroxyapatite-coated surfaces in the transmucosal region yielded similar inflammatory response and is suggested to be as biocompatible as commercially pure titanium surfaces.

  • 38. Del Corso, Marco
    et al.
    Vervelle, Alain
    Simonpieri, Alain
    Jimbo, Ryo
    Malmö högskola, Faculty of Health and Society (HS), Department of Biomedical Science (BMV).
    Inchingolo, Francesco
    Sammartino, Gilberto
    Ehrenfest, David M. Dohan
    Current Knowledge and Perspectives for the Use of Platelet-Rich Plasma (PRP) and Platelet-Rich Fibrin (PRF) in Oral and Maxillofacial Surgery Part 1: Periodontal and Dentoalveolar Surgery2012In: Current Pharmaceutical Biotechnology, ISSN 1389-2010, E-ISSN 1873-4316, Vol. 13, no 7, p. 1207-1230Article, review/survey (Refereed)
    Abstract [en]

    Platelet concentrates for surgical use are innovative tools of regenerative medicine, and were widely tested in oral and maxillofacial surgery. Unfortunately, the literature on the topic is contradictory and the published data are difficult to sort and interpret. In periodontology and dentoalveolar surgery, the literature is particularly dense about the use of the various forms of Platelet-Rich Plasma (PRP) - Pure Platelet-Rich Plasma (P-PRP) or Leukocyte-and Platelet-Rich Plasma (L-PRP) - but still limited about Platelet-Rich Fibrin (PRF) subfamilies. In this first article, we describe and discuss the current published knowledge about the use of PRP and PRF during tooth avulsion or extraction, mucogingival surgery, Guided Tissue Regeneration (GTR) or bone filling of periodontal intrabony defects, and regeneration of alveolar ridges using Guided Bone Regeneration (GBR), in a comprehensive way and in order to avoid the traps of a confusing literature and to highlight the underlying universal mechanisms of these products. Finally, we particularly insist on the perspectives in this field, through the description and illustration of the systematic use of L-PRF (Leukocyte-and Platelet-Rich Fibrin) clots and membranes during tooth avulsion, cyst exeresis or the treatment of gingival recessions by root coverage. The use of L-PRF also allowed to define new therapeutic principles: NTR (Natural Tissue Regeneration) for the treatment of periodontal intrabony lesions and Natural Bone Regeneration (NBR) for the reconstruction of the alveolar ridges. In periodontology, this field of research will soon find his golden age by the development of user-friendly platelet concentrate procedures, and the definition of new efficient concepts and clinical protocols.

  • 39. Dohan Ehrenfest, David M
    et al.
    Bielecki, Tomasz
    Jimbo, Ryo
    Malmö högskola, Faculty of Odontology (OD).
    Barbe, Giovanni
    Del Corso, Marco
    Inchingolo, Francesco
    Sammartino, Gilberto
    Do the fibrin architecture and leukocyte content influence the growth factor release of platelet concentrates? An evidence-based answer comparing a pure platelet-rich plasma (P-PRP) gel and a leukocyte- and platelet-rich fibrin (L-PRF)2012In: Current Pharmaceutical Biotechnology, ISSN 1389-2010, E-ISSN 1873-4316, Vol. 13, no 7, p. 1145-1152Article, review/survey (Refereed)
    Abstract [en]

    Platelet concentrates for surgical use are tools of regenerative medicine designed for the local release of platelet growth factors into a surgical or wounded site, in order to stimulate tissue healing or regeneration. Leukocyte content and fibrin architecture are 2 key characteristics of all platelet concentrates and allow to classify these technologies in 4 families, but very little is known about the impact of these 2 parameters on the intrinsic biology of these products. In this demonstration, we highlight some outstanding differences in the growth factor and matrix protein release between 2 families of platelet concentrate: Pure Platelet-Rich Plasma (P-PRP, here the Anitua's PRGF - Preparation Rich in Growth Factors - technique) and Leukocyte- and Platelet-Rich Fibrin (L-PRF, here the Choukroun's method). These 2 families are the extreme opposites in terms of fibrin architecture and leukocyte content. The slow release of 3 key growth factors (Transforming Growth Factor β1 (TGFβ1), Platelet-Derived Growth Factor AB (PDGF-AB) and Vascular Endothelial Growth Factor (VEGF)) and matrix proteins (fibronectin, vitronectin and thrombospondin-1) from the L-PRF and P-PRP gel membranes in culture medium is described and discussed. During 7 days, the L-PRF membranes slowly release significantly larger amounts of all these molecules than the P-PRP gel membranes, and the 2 products display different release patterns. In both platelet concentrates, vitronectin is the sole molecule to be released almost completely after only 4 hours, suggesting that this molecule is not trapped in the fibrin matrix and not produced by the leukocytes. Moreover the P-PRP gel membranes completely dissolve in the culture medium after less than 5 days only, while the L-PRF membranes are still intact after 7 days. This simple demonstration shows that the polymerization and final architecture of the fibrin matrix considerably influence the strength and the growth factor trapping/release potential of the membrane. It also suggests that the leukocyte populations have a strong influence on the release of some growth factors, particularly TGFβ1. Finally, the various platelet concentrates present very different biological characteristics, and an accurate definition and characterization of the different families of product is a key issue for a better understanding and comparison of the reported clinical effects of these surgical adjuvants.

  • 40.
    Galli, Silvia
    et al.
    Malmö högskola, Faculty of Odontology (OD).
    Andersson, Martin
    Jinno, Yohei
    Malmö högskola, Faculty of Odontology (OD).
    Karlsson, Johan
    He, Wenxiao
    Xue, Ying
    Mustafa, Kamal
    Wennerberg, Ann
    Malmö högskola, Faculty of Odontology (OD).
    Jimbo, Ryo
    Malmö högskola, Faculty of Odontology (OD).
    Magnesium release from mesoporous carriers on endosseus implants does not influence bone maturation at 6 weeks in rabbit bone2017In: Journal of Biomedical Materials Research. Part B - Applied biomaterials, ISSN 1552-4973, E-ISSN 1552-4981, Vol. 105, no 7, p. 2118-2125Article in journal (Refereed)
    Abstract [en]

    Objectives: The release of magnesium ions (Mg21) from titanium surfaces has been shown to boost the initial biological response of peri-implant bone and to increase the biomechanical strength of osseointegration. The objective of the present paper was to investigate if the initial improve- ment in osseointegration would influence the bone remodel- ing also during the maturation stage of bone healing. Methods: Titanium implants were coated with mesoporous titania layers and either loaded with Mg21 (test group) or left untreated (control group). The implants were inserted in the tibiae of 10 New Zealand White rabbits. Osseointegration was assessed after 6 weeks by means of biomechanical test- ing (RTQ), non-decalcified histology and histomorphometry (BIC%, BA%, NBA%). The expression of genes involved in the bone formation and remodeling was quantified using qPCR. Results: Mg21 releasing mesoporous titania coatings showed, on average, higher removal torques and histomorphometrical outcomes (RTQ: 17.2 Ncm vs. 15 Ncm; BIC: 38.8% vs. 32.1%; BA%: 71.6% vs. 64%; NBA% 62.5% vs. 54% for the tests vs the controls); however, the differences were not statistically significant. Three osteogenic markers, osteocalcin (OC), colla- gen 1 alpha 1 (COL1A1), and alkalin phosphatase (ALPL), were respectively 2-fold, 1.53-fold, and 1.13-fold up-regulated in the control group compared to the test. The expression of COL1A1 was particularly high in both groups, while the biomarkers for remodeling and inflammation showed a low expression in both groups. Significance: The results suggested that the initial enhancement in osseointegration induced by magnesium release from mesoporous titania coatings has no detrimental effects during bone maturation.

  • 41.
    Galli, Silvia
    et al.
    Malmö högskola, Faculty of Odontology (OD).
    Hammel, Jörg U.
    Herzen, Julia
    Damm, Timo
    Jimbo, Ryo
    Malmö högskola, Faculty of Odontology (OD).
    Beckmann, Felix
    Wennerberg, Ann
    Malmö högskola, Faculty of Odontology (OD).
    Willumeit-Römer, Regine
    Evaluation of the degradation behavior of resorbable metal implants for in vivo osteosynthesis by synchrotron radiation based x-ray tomography and histology2016In: Developments in X-Ray Tomography X, SPIE - International Society for Optical Engineering, 2016Conference paper (Refereed)
    Abstract [en]

    Magnesium(Mg)-alloys are promising candidates as temporary implants for orthopedic and cranio-facial applications. They can sustain tissues during healing, thanks to favorable mechanical properties, and then they slowly degrade into biocompatible products, avoiding the need of a second surgery for implant removal. They have the potential to benefit a vast number of patients, especially children and elderly patients. However, to be able to tailor their degradation to match the speed of tissue regeneration it is crucial to understand how they actually degrade in the living organism. We utilized high-resolution synchrotron-based tomography at the beamline P05 operated by HZG at the storage ring PETRA III at DESY to study the degradation of 3 novel Mg-alloys in rat bone and the consequent bone response. On three-dimensional reconstructions of the bone-implant explants we were able to follow the dynamic transformation that the materials underwent at different healing times and on the basis of absorption coefficients we could distinguish and quantify the amount of remaining implants, the corrosion layers and the new bone. This was a great advantage compared to laboratory CT, for which the limitation in contrast and in resolution made impossible to discriminate between original alloy, degradation products and bone, leading to inaccurate determination of the materials degradation rates. The same samples imaged by tomography were used for non-decalcified histology. The combination of histological and tomographical images provided new insight on the nature of the bone-to-implant interface and of the degradation products, which appeared to have great similarities to the host bone.

  • 42.
    Galli, Silvia
    et al.
    Malmö högskola, Faculty of Odontology (OD).
    Jimbo, Ryo
    Malmö högskola, Faculty of Odontology (OD).
    Andersson, Martin
    Bryington, Matthew
    Albrektsson, Tomas
    Malmö högskola, Faculty of Odontology (OD).
    Surface characterization and clinical review of two commercially available implants2013In: Implant Dentistry, ISSN 1056-6163, E-ISSN 1538-2982, Vol. 22, no 5, p. 507-518Article in journal (Refereed)
    Abstract [en]

    PURPOSE: To characterize topographically and chemically the surfaces of 2 commercially available implants. Furthermore, to gather an overview of the clinical results of these implant systems. MATERIALS AND METHODS: Two commercially available oral implants were analyzed using optical interferometry, scanning electron microscopy, and energy dispersive spectroscopy. In addition, a literature search for all the clinical articles on the same implants was performed. RESULTS: No significant differences of topographical parameters were found between the 2 implants, except for the hybrid parameter Sdr presenting significant higher values for the Ankylos implants. Both surfaces had a homogenous microporosity. At higher magnifications of scanning electron microscope images, evenly distributed nanostructures (approximately 10 nm) were visible. Chemically, mainly titanium, oxygen and carbon were detected. Fifty-six clinical articles were included for the review. The implant survival rates (minimum follow-up: 5 years) ranged between 87.7% and 100%. CONCLUSIONS: The examined commercially available implants showed a moderately rough surface, with a homogenous microporosity. Nanofeatures were detected on the surface of both implants. The clinical performances of these implants were comparable to that of other commercialized implant systems.

  • 43.
    Galli, Silvia
    et al.
    Malmö högskola, Faculty of Odontology (OD).
    Jimbo, Ryo
    Malmö högskola, Faculty of Odontology (OD).
    Naito, Yoshihito
    Malmö högskola, Faculty of Odontology (OD).
    Berner, Simon
    Dard, Michel
    Wennerberg, Ann
    Malmö högskola, Faculty of Odontology (OD).
    Chemically modified titanium-zirconium implants in comparison with commercially pure titanium controls stimulate the early molecular pathways of bone healing2017In: Clinical Oral Implants Research, ISSN 0905-7161, E-ISSN 1600-0501, Vol. 28, no 10, p. 1234-1240Article in journal (Refereed)
    Abstract [en]

    OBJECTIVES: Titanium-zirconium (TiZr) has been proposed as a mechanically stronger alternative to commercially pure titanium for oral and orthopaedic implants. However, not much is known on the osseointegration kinetics of TiZr surfaces. In this study, we aimed to identify the genetic response of bone around TiZr implants compared to pure Ti. MATERIAL AND METHODS: Microtextured and hydrophilic TiZr implants (tests) and cpTi implants grade IV (controls) were placed in the tibia of 30 New Zealand white rabbits. At 2, 4 and 12 weeks, the implants were subjected to removal torque test (RTQ). The expression of a panel of genes involved in the process of osseointegration was measured in the bone around the test and control implants by means of quantitative real-time polymerase chain reaction (PCR) and compared to the control samples. RESULTS: The controls yielded statistically significant higher RTQ at 4 weeks, but the RTQ of the tests had a larger increase between 4 and 12 weeks, when both groups reached similar values. The gene expression analysis showed that all selected markers for bone formation, bone remodelling and cytokines were significantly upregulated around TiZr implants after 2 weeks. After 4 weeks of healing, two bone formation markers were significantly more expressed in the test samples, while at 12 weeks, the expression of all genes was similar in the two groups. CONCLUSIONS: TiZr implants showed comparable biomechanical outcomes to cpTi up to 12 weeks of healing. However, at early healing stages, they showed a significant upregulation of osteogenesis and osteoclastogenesis markers.

  • 44.
    Galli, Silvia
    et al.
    Malmö högskola, Faculty of Odontology (OD).
    Jimbo, Ryo
    Malmö högskola, Faculty of Odontology (OD).
    Tovar, Nick
    Yoo, Daniel
    Anchieta, Rodolfo
    Yamaguchi, Satoshi
    Coelho, Paulo G
    The effect of osteotomy dimension on osseointegration to resorbable media-treated implants: a study in the sheep2015In: Journal of biomaterials applications, ISSN 0885-3282, E-ISSN 1530-8022, Vol. 29, no 8, p. 1068-1074Article in journal (Refereed)
    Abstract [en]

    The drilling technique and the surface characteristics are known to influence the healing times of oral implants. The influence of osteotomy dimension on osseointegration of microroughned implant surfaces treated with resorbable blasting media was tested in an in vivo model. Ninety-six implants (ø4.5 mm, 8 mm in length) with resorbable blasting media-treated surfaces were placed in the ileum of six sheep. The final osteotomy diameters were 4.6mm (reamer), 4.1mm (loose), 3.7mm (medium), and 3.2mm (tight). After three and six weeks healing, the implants were biomechanically tested and histologically evaluated. Statistical analysis was performed using Page L trend test for ordered and paired sample and linear regression, with significance level at p < 0.05. An overall increase in all dependent variables was observed with the reduction of osteotomy diameter. In addition, all osseointegration scores increased over time. At three weeks, the retention was significantly higher for smaller osteo- tomies. The histological sections depicted intimate contact of bone with all the implant surfaces and osteoblast lines were visible in all sections. The resorbable blasting media microroughed surfaces achieved successful osseointegration for all the instrumentation procedures tested, with higher osseointegration scores for the high insertion torque group.

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  • 45.
    Galli, Silvia
    et al.
    Malmö högskola, Faculty of Odontology (OD).
    Naito, Yoshihito
    Malmö högskola, Faculty of Odontology (OD).
    Karlsson, Johan
    He, Wenxiao
    Andersson, Martin
    Wennerberg, Ann
    Malmö högskola, Faculty of Odontology (OD).
    Jimbo, Ryo
    Malmö högskola, Faculty of Odontology (OD).
    Osteoconductive potential of mesoporous titania implant surfaces loaded with magnesium: an experimental study in the rabbit2015In: Clinical Implant Dentistry and Related Research, ISSN 1523-0899, E-ISSN 1708-8208, Vol. 17, no 6, p. 1048-1059Article in journal (Refereed)
    Abstract [en]

    Background: Mesoporous coatings enable incorporation of functional substances and sustainedly release them at the implant site. One bioactive substance that can be incorporated in mesoporous is magnesium, which is strongly involved in bone metabolism and in osteoblast interaction. Purpose: The aim of this experimental study was to evaluate the effect of incorporation of magnesium into mesoporous coatings of oral implants on early stages of osseointegration. Material and Methods: Titanium implants were coated with thin films of mesoporous TiO2 having pore diameters of 6 nm and were loaded with magnesium. The implant surfaces were extensively characterized by means of interferometry, atomic force microscopy, scanning electron microscopy, and energy-dispersive spectroscopy and then placed in the tibiae of 10 rabbits. After 3 weeks of healing, osseointegration was evaluated by means of removal torque testing and histology and histomorphometry. Results: Histological and biomechanical analyses revealed no side effects and successful osseointegration of the implants. The biomechanical evaluation evidenced a significant effect of magnesium doping on strengthening the implant-bone interface. Conclusions: A local release of magnesium from the implant surfaces enhances implant retention at the early stage of healing (3 weeks after implantation), which is highly desirable for early loading of the implant.

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  • 46.
    Galli, Silvia
    et al.
    Malmö högskola, Faculty of Odontology (OD).
    Naito, Yoshihito
    Malmö högskola, Faculty of Odontology (OD).
    Karlsson, Johan
    He, Wenxiao
    Miyamoto, Ikuya
    Xue, Ying
    Andersson, Martin
    Mustafa, Kamal
    Wennerberg, Ann
    Malmö högskola, Faculty of Odontology (OD).
    Jimbo, Ryo
    Malmö högskola, Faculty of Odontology (OD).
    Local release of magnesium from mesoporous TiO2 coatings stimulates the peri-implant expression of osteogenic markers and improves osteoconductivity in vivo2014In: Acta Biomaterialia, ISSN 1742-7061, E-ISSN 1878-7568, Vol. 10, no 12, p. 5193-5201Article in journal (Refereed)
    Abstract [en]

    Local release of Mg ions from titanium implant surfaces has been shown to enhance implant retention and integration. To clarify the biological events that lead to this positive outcome, threaded implants coated with mesoporous TiO2 thin films were loaded with Mg-ions and placed in the tibia of rabbits for 3 weeks, after surface characterization. Non-loaded mesoporous coated implants were used as controls. Peri-implant gene expression of a set of osteogenic and inflammatory assays was quantified by means of real-time quantitative polymerase chain reaction. The expression of three osteogenic markers (OC, RUNX-2 and IGF-1) was significantly more pronounced in the test specimens, suggesting that the release of Mg ions directly at the implant sites may stimulate an osteogenic environment. Furthermore, bone healing around implants was evaluated on histological slides and by diffraction-enhanced imaging (DEI), using synchrotron radiation. The histological analysis demonstrated new bone formation around all implants, without negative responses, with a significant increase in the number of threads filled with new bone for test surfaces. DEI analysis attested the high mineral content of the newly formed bone. Improved surface osteoconductivity and increased expression of genes involved in the bone regeneration were found for magnesium-incorporation of mesoporous TiO2 coatings.

  • 47.
    Galli, Silvia
    et al.
    Malmö högskola, Faculty of Odontology (OD).
    Stocchero, Michele
    Malmö högskola, Faculty of Odontology (OD).
    Andersson, M.
    Karlsson, J.
    He, W.
    Lilin, T.
    Wennerberg, Ann
    Malmö högskola, Faculty of Odontology (OD).
    Jimbo, Ryo
    Malmö högskola, Faculty of Odontology (OD).
    The effect of magnesium on early osseointegration in osteoporotic bone: a histological and gene expression investigation2017In: Osteoporosis International, ISSN 0937-941X, E-ISSN 1433-2965, Vol. 28, no 7, p. 2195-2205Article in journal (Refereed)
    Abstract [en]

    Magnesium has a key role in osteoporosis and could enhance implant osseointegration in osteoporotic patients. Titanium implants impregnated with Mg ions were installed in the tibia of ovariectomized rats. The release of Mg induced a significant increase of bone formation and the expression of anabolic markers in the peri-implant bone. The success of endosseous implants is highly predictable in patients possessing normal bone status, but it may be impaired in patients with osteoporosis. Thus, the application of strategies that adjuvate implant healing in compromized sites is of great interest. Magnesium has a key role in osteoporosis prevention and it is an interesting candidate for this purpose. In this study, the cellular and molecular effects of magnesium release from implants were investigated at the early healing stages of implant integration. Osteoporosis was induced in 24 female rats by means of ovariectomy and low-calcium diet. Titanium mini-screws were coated with mesoporous titania films and were loaded with magnesium (test group) or left as native (control group). The implants were inserted in the tibia and femur of the rats. One, 2 and 7 days after implantation, the implants were retrieved and histologically examined. In addition, expression of genes was evaluated in the peri-implant bone tissue at day 7 by means of quantitative polymerase chain reactions with pathway-oriented arrays. The histological evaluation revealed that new bone formation started already during the first week of healing for both groups. However, around the test implants, new bone was significantly more abundant and spread along a larger surface of the implants. In addition, the release of magnesium induced a significantly higher expression of BMP6. These results provide evidence that the release of magnesium promoted rapid bone formation and the activation of osteogenic signals in the vicinity of implants placed in osteoporotic bone.

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  • 48.
    Ghariani, L
    et al.
    Department of Oral Surgical Sciences, Faculty of Dentistry, Beirut Arab University, Beirut, Lebanon.
    Segaan, Lucette
    Department of Oral Rehabilitation Sciences, Faculty of Dentistry, Beirut Arab University, Beirut, Lebanon.
    Rayyan, Mohammad
    Department of Oral Surgical Sciences, Faculty of Dentistry, Beirut Arab University, Beirut, Lebanon; Department of Fixed Prosthodontics, Faculty of dentistry, Misr University for Science and Technology, Giza Governorate, Giza, Egypt.
    Galli, Silvia
    Malmö högskola, Faculty of Odontology (OD).
    Jimbo, Ryo
    Malmö högskola, Faculty of Odontology (OD).
    Ibrahim, Ahmed
    Public Health Service (Folktandvården), Gefle, Sweden.
    Does crown/implant ratio influence the survival and marginal bone level of short single implants in the mandibular molar?: A preliminary investigation consisting of 12 patients2016In: Journal of Oral Rehabilitation, E-ISSN 1365-2842, Vol. 43, no 2, p. 127-135Article in journal (Refereed)
    Abstract [en]

    Crown/implant (C/I) ratio has been proven to not affect the survival of the implants; however, it is also a fact that no evidence exists with regard to the use of single short implants in the mandibular molar. The aim of this study was to determine whether the crown/implant ratios of single implant-supported fixed restorations on implants of 6-8 mm in the mandibular molar have an impact on the implant survival and marginal bone maintenance. Twelve short dental implants (6-8 mm) were installed and restored with single crowns, loaded after 3 months of healing. The restorations were divided according to crown-to-implant ratio into two groups: Group 1: C/I < 2.0 and Group 2: C/I >== 2.0. Alveolar bone loss was measured using CBCT scan, taken at the implant placement and after 12 months follow-up from loading. Reduced implant/crown ratio shown no statistic significant differences on implant survival and the alveolar bone level compared with recommended implant/crown ratio. Within the limitation of this study, it can be concluded that reduced C/I ratio could be used as a substitute for recommended C/I ratio in severely mandibular atrophic residual alveolar ridges.

  • 49. Gil, Luiz F.
    et al.
    Suzuki, Marcelo
    Janal, Malvin N.
    Tovar, Nick
    Marin, Charles
    Granato, Rodrigo
    Bonfante, Estevam A.
    Jimbo, Ryo
    Malmö högskola, Faculty of Odontology (OD).
    Gil, Jose N.
    Coelho, Paulo G.
    Progressive plateau root form dental implant osseointegration: a human retrieval study2015In: Journal of Biomedical Materials Research. Part B - Applied biomaterials, ISSN 1552-4973, E-ISSN 1552-4981, Vol. 103, no 6, p. 1328-1332Article in journal (Refereed)
    Abstract [en]

    Although preclinical and sparse human histology retrieval studies have shown that the interface between implant and bone is constantly remodeling, no human retrieval database has been developed to determine the effect of functional loading time and other clinical/implant design variables on osseointegration. The present study tested the hypothesis that bone-to-implant contact (BIC) and bone area fraction occupancy (BAFO) increase over functional loading time around dental implants. Due to prosthetic retreatment reasons, 93 human implant retrievals from the same manufacturer (Bicon LLC, Boston, MA, USA) were obtained over a period of approximately 15 years. The retrieved implants were under functional loading from 120 days to approximate to 18 years and were histomorphologic/metrically evaluated. BIC/BAFO were assessed as a function of multiple independent variables: implant surface type, diameter, length, jaw (maxilla/mandible), region (anterior/posterior), and time of functional loading. The results showed that both BIC and BAFO increased over time independently of implant design/clinical variables, supporting the postulated hypothesis. (c) 2014 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 103B: 1328-1332, 2015.

  • 50. Giro, Gabriela
    et al.
    Tovar, Nick
    Marin, Charles
    Bonfante, Estevam Augusto
    Jimbo, Ryo
    Malmö högskola, Faculty of Odontology (OD).
    Suzuki, Marcelo
    Janal, Malvin N
    Coelho, Paulo G
    The effect of simplifying dental implant drilling sequence on osseointegration: an experimental study in dogs2013In: International Journal of Biomaterials, ISSN 1687-8787, E-ISSN 1687-8795, Vol. 2013, article id 230310Article in journal (Refereed)
    Abstract [en]

    Objectives. To test the hypothesis that there would be no differences in osseointegration by reducing the number of drills for site preparation relative to conventional drilling sequence. Methods. Seventy-two implants were bilaterally placed in the tibia of 18 beagle dogs and remained for 1, 3, and 5 weeks. Thirty-six implants were 3.75 mm in diameter and the other 36 were 4.2 mm. Half of the implants of each diameter were placed under a simplified technique (pilot drill + final diameter drill) and the other half were placed under conventional drilling where multiple drills of increasing diameter were utilized. After euthanisation, the bone-implant samples were processed and referred to histological analysis. Bone-to-implant contact (BIC) and bone-area-fraction occupancy (BAFO) were assessed. Statistical analyses were performed by GLM ANOVA at 95% level of significance considering implant diameter, time in vivo, and drilling procedure as independent variables and BIC and BAFO as the dependent variables. Results. Both techniques led to implant integration. No differences in BIC and BAFO were observed between drilling procedures as time elapsed in vivo. Conclusions. The simplified drilling protocol presented comparable osseointegration outcomes to the conventional protocol, which proved the initial hypothesis.

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