Malmö University Publications
Change search
Refine search result
1 - 10 of 10
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 1.
    Braian, Michael
    et al.
    Malmö University, Faculty of Odontology (OD).
    Wennerberg, Ann
    Department of Prosthodontics, Institute of Odontology, Sahlgrenska Academy, Gothenburg University, Gothenburg, Sweden.
    Trueness and precision of 5 intraoral scanners for scanning edentulous and dentate complete-arch mandibular casts: A comparative in vitro study2019In: The Journal of prosthetic dentistry (Print), ISSN 0022-3913, E-ISSN 1097-6841, Vol. 122, no 2, p. 129-136Article in journal (Refereed)
    Abstract [en]

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

  • 2.
    Gjelvold, Björn
    et al.
    Malmö University, Faculty of Odontology (OD). Clinic of Prosthodontics, Centre of Dental Specialist Care, Lund, Sweden.
    Mahmood, Deyar Jallal Hadi
    Malmö University, Faculty of Odontology (OD).
    Wennerberg, Ann
    Department of Prosthodontics, Institute of Odontology, Sahlgrenska Academy University of Gothenburg, Gothenburg, Sweden.
    Accuracy of surgical guides from 2 different desktop 3D printers for computed tomography-guided surgery2019In: The Journal of prosthetic dentistry (Print), ISSN 0022-3913, E-ISSN 1097-6841, Vol. 121, no 3, p. 498-503, article id S0022-3913(18)30677-2Article in journal (Refereed)
    Abstract [en]

    STATEMENT OF PROBLEM: Different factors influence the degree of deviation in dental implant position after computed tomography-guided surgery. The surgical guide-manufacturing process with desktop 3D printers is such a factor, but its accuracy has not been fully evaluated.

    PURPOSE: The purpose of this in vitro study was to evaluate the deviation in final dental implant position after the use of surgical guides fabricated from 2 different desktop 3D printers using a digital workflow.

    MATERIAL AND METHODS: Twenty 3D-printed resin models were prepared with missing maxillary premolar. After preoperative planning, 10 surgical guides were produced with a stereolithography printer and 10 with a digital light-processing (DLP) printer. A guided surgery was performed; 20 dental implants (3.8×12 mm) were installed, and a digital scan of the dental implants was made. Deviations between the planned and final position of the dental implants were evaluated for both the groups.

    RESULTS: A statistically significant difference between stereolithography and DLP were found for deviation at entry point (P=.023) and the vertical implant position (P=.009). Overall lower deviations were found for the guides from the DLP printer, with the exception of deviation in horizontal implant position.

    CONCLUSIONS: The tested desktop 3D printers were able to produce surgical guides with similar deviations with regard to the final dental implant position, but the DLP printer proved more accurate concerning deviations at entry point and vertical implant position.

  • 3.
    Hammoudi, Wedad
    et al.
    Department of Dental Medicine, Karolinska Institutet, Huddinge, Sweden; Specialist in Dental Prosthetics, Department of Prosthetic Dentistry, Folktandvården Eastmaninstitutet, Stockholm, Sweden.
    Trulsson, Mats
    Division of Oral Diagnosis and Rehabilitation, Department of Dental Medicine, Karolinska Institutet, Huddinge, Sweden;.
    Svensson, Peter
    Malmö University, Faculty of Odontology (OD). Section of Orofacial Pain and Jaw Function, Department of Dentistry and Oral Health, Aarhus university, Aarhus, Denmark.
    Smedberg, Jan-Ivan
    Department of Dental Medicine, Karolinska Institutet, Huddinge, Sweden; Specialist in Dental Prosthetics, Department of Prosthetic Dentistry, Folktandvården Eastmaninstitutet, Stockholm, Sweden.
    Long-term results of a randomized clinical trial of 2 types of ceramic crowns in participants with extensive tooth wear2022In: The Journal of prosthetic dentistry (Print), ISSN 0022-3913, E-ISSN 1097-6841, Vol. 127, no 2, p. 248-257, article id S0022-3913(20)30651-XArticle in journal (Refereed)
    Abstract [en]

    STATEMENT OF PROBLEM: Evidence is sparse regarding the long-term outcomes of restorative treatment of patients with extensive tooth wear.

    PURPOSE: The purpose of this long-term prospective randomized clinical trial was to evaluate the performance and success rate of pressed lithium disilicate (LD) and translucent zirconia (TZ) crowns in participants with extensive tooth wear.

    MATERIAL AND METHODS: A total of 62 participants with extensive tooth wear (17 women, 45 men; mean age 44.8 years; range 25-63 years) received a total of 713 crowns, LD=362 and TZ=351. Both types of crowns had chamfer preparations and were adhesively luted with dual-polymerizing composite resin cement (PANAVIA F 2.0; Kuraray Noritake Dental Inc). The restorations were clinically reevaluated on average 14, 31, 39, 54, and 65 months after insertion of the crowns according to the modified United States Public Health Service (USPHS) criteria.

    RESULTS: After an observation period of up to 6 years, the survival rate for both types of crowns was 99.7%, with 1 lost LD crown after 1 year as a result of loss of retention and 1 lost TZ crown after 3 years because of tooth fracture at the cemento-enamel junction. The success rates were similar for both types of crowns: 98.6% for LD and 99.1% for TZ. Reasons for failures were that 3 participants in each group developed apical lesions, minimal ceramic fractures, or their crowns were rebonded after loss of adhesion. Assessment of color at baseline was significantly different with a better match for LD (84.8% Alfa, 15.2% Bravo) than for TZ crowns (36.5% Alfa, 63.5% Bravo), including TZ crowns with veneered porcelain (P<.001). Secondary caries and cracks did not occur. A post hoc analysis of clinical performance did not indicate any significant differences between extensive tooth wear with primarily mechanical or chemical factors.

    CONCLUSIONS: No differences were found between the 2 types of ceramic materials concerning the long-term success and clinical performance, except that TZ crowns were rated by a blinded clinician as less esthetic than LD crowns. The use of high-strength ceramic materials, as well as reliable adhesive bonding, are probably the key factors in the long-term success of ceramic crowns in participants with extensive tooth wear independent of the specific etiology.

  • 4.
    Kronström, Mats
    et al.
    Malmö högskola, Faculty of Odontology (OD).
    Widbom, Tor
    Löfquist, Liselott E
    Henningson, Christer
    Widbom, Christin
    Lundberg, Tomas
    Early functional loading of conical Brånemark implants in the edentulous mandible: a 12-month follow-up clinical report2003In: The Journal of prosthetic dentistry (Print), ISSN 0022-3913, E-ISSN 1097-6841, Vol. 89, no 4, p. 335-340Article in journal (Other academic)
    Abstract [en]

    Treatment of patients with implant-supported mandibular fixed prostheses performed according to an early loading concept has shown excellent results in several reports. The outcome of such treatments with 4 implants, in which the posteriors are distally inclined, has not been reported. This clinical report describes a 12-month evaluation of 17 consecutive patients with 68 conical Branemark implants placed between the mental foramina according to a 1-stage surgical procedure. Fixed mandibular prostheses were connected to the implants an average of 33 days after implant placement. Clinical and radiographic examinations were performed at the time of placement of the fixed prosthesis and at a 12-month examination. Five implants were lost during the observation period, 3 before loading and 2 after prosthesis connection, rendering an implant survival rate of 93%. One patient lost her prosthesis because of a failing implant. The average marginal bone loss was 0.24 mm.

  • 5.
    Lövgren, Niklas
    et al.
    Malmö högskola, Faculty of Odontology (OD).
    Roxner, Rikard
    Malmö högskola, Faculty of Odontology (OD).
    Klemendz, Susanne
    Malmö högskola, Faculty of Odontology (OD).
    Larsson, Christel
    Malmö högskola, Faculty of Odontology (OD).
    Effect of production method on surface roughness, marginal and internal fit, and retention of cobalt-chromium single crowns2017In: The Journal of prosthetic dentistry (Print), ISSN 0022-3913, E-ISSN 1097-6841, Vol. 118, no 1, p. 95-101Article in journal (Refereed)
    Abstract [en]

    STATEMENT OF PROBLEM: New production methods have been developed for metal ceramic restorations. Different production methods may show different surface roughness and fit, which may affect retention and long-term success. PURPOSE: The purpose of this in vitro study was to examine 3 different production methods with regard to surface roughness, marginal and internal fit, and retention of cobalt-chromium alloy single-crown copings. MATERIAL AND METHODS: A master abutment of a premolar mandibular tooth preparation with 4-mm height and a 0.6-mm deep 120-degree chamfer finish line with a 12-degree angle of convergence was replicated in die stone and scanned. Thirty-six cobalt-chromium alloy copings were produced using 3 different production techniques. Twelve copings were produced by laser-sintering, 12 by milling, and 12 by milled wax/lost wax. The surface microstructure of 2 copings in each group was analyzed using interferometry. The remaining 10 copings in each group were used to evaluate marginal and internal fit by using an impression material replica method, and retention was evaluated by using a uniaxial tensile force pull-off test. The copings from each test group were cemented with zinc phosphate cement onto resin abutments. Statistical analyses of differences in marginal and internal fit were performed using 1-way ANOVA and the Mann-Whitney U test. Differences in surface topography were analyzed with the Kruskal-Wallis and Mann-Whitney U tests for nonparametric data. Differences in retentive values were analyzed using the Mann-Whitney U test for nonparametric data (all α=.05). RESULTS: Differences in surface microstructure were seen. The laser-sintered copings showed increased surface roughness compared with milled and milled wax/lost wax copings. Differences in marginal and internal fit were noted. Laser-sintered showed significantly smaller spaces between coping and abutment than milled wax/lost wax copings (P=.003). At the margins, laser-sintered copings showed significantly smaller spaces than either the milled wax/lost wax group (P=.002) or the milled group (P=.002). At the chamfer, laser-sintered copings showed significantly smaller spaces than milled wax/lost wax copings (P=.005). At the center of the axial walls, laser-sintered copings showed significantly smaller spaces than those in the milled wax/lost wax (P=.004) and milled copings (P=.005). No significant differences were noted between milled and milled wax/lost wax copings (P>.05). No significant differences were detected regarding retentive forces in the pull-off tests (P>.05). CONCLUSIONS: Laser-sintered Co-Cr crown copings showed increased surface roughness and better internal and marginal fit than copings produced by milling or milled wax/lost wax technique. However, the crown pull-off tests did not reveal any significant differences.

    Download full text (pdf)
    fulltext
  • 6.
    Matthys, Carine
    et al.
    Clinic for Removable Prosthodontics, Dental School, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium.
    Vervaeke, Stijn
    Specialist, Periodontics and Implantology, Department of Periodontology and Oral Implantology, Dental School, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium.
    Jacquet, Wolfgang
    Applied Mathematics-Statistics, Department of Oral Health Sciences, and Department of Educational Sciences Localities Ontologies Commons Integrated, University of Amsterdam Brussel, Brussels, Belgium; Anton de Kom University of Suriname, Paramaribo, Suriname; Dental School, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium.
    De Bruyn, Hugo
    Malmö University, Faculty of Odontology (OD). Department of Periodontology and Oral Implantology, Dental School, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium; Department of Dentistry, Radboud University Nijmegen, Nijmegen, The Netherlands.
    Impact of crestal bone resorption on quality of life and professional maintenance with conventional dentures or locator-retained mandibular implant overdentures2018In: The Journal of prosthetic dentistry (Print), ISSN 0022-3913, E-ISSN 1097-6841, Vol. 120, no 6, p. 886-894Article in journal (Refereed)
    Abstract [en]

    STATEMENT OF PROBLEM: The influence of the mandibular resorption profile on clinical outcome after converting a conventional complete denture into a Locator-retained implant overdenture is unknown. PURPOSE: The purpose of this prospective study was to assess the oral health-related quality of life (OHRQoL) and prosthetic maintenance of mandibular overdentures on 2 Locator abutments in relation to the resorption degree of the edentulous mandible. MATERIAL AND METHODS: Twenty-five participants were treated and classified according to the Cawood and Howell (CAW-H) resorption classification for the resorption profile of the mandible, CAW-H group III-IV (n=14) and CAW-H group V (n=11). Participants received conventional complete dentures (CDs) before implant placement and immediate nonfunctional loading on locators with a resilient liner. After 3 months, the attachments were functionally activated. Assessments were made using the Oral Health Impact Profile 14 (OHIP-14) questionnaires with existing CDs and new CDs at 1, 3, and 15 months after loading. Prosthetic maintenance (repairs, rebasings, replacement of retention parts) and biological prosthetic aftercare were assessed. For comparison between groups, the Kruskal-Wallis and Mann-Whitney U tests were applied for continuous and ordinal variables and the chi-square test for cross-tabulations. To analyze repeated OHIP-14 scores, the Friedman test was used for ordered alternatives to test whether the measurements differed (overall significance level alpha=.05). Then the Wilcoxon signed rank test was conducted to detect specific differences (alpha=.05). RESULTS: OHIP-14 scores decreased significantly after implant placement and functional connection for the whole population (P<.001) and for both sub groups, the CAW-H group III-IV (P<.001) and the CAW-H group V (P=.013). CAW-H group V participants needed more retention inserts than CAW-H group III-IV participants (26 versus 3, respectively; P=.006). The incidence of repair and rebasing was limited for both groups, and biological aftercare and pain relief were comparable. CONCLUSIONS: Changing a CD to an overdenture significantly improved ORLQoL regardless of the resorption degree, but heavily resorbed mandibles require more replacements of retention inserts.

  • 7.
    Nilsson, Göran
    et al.
    Department of Prosthetic Dentistry Specialist clinic, Kalmar County Public Dental Service, Kalmar, Sweden.
    Ellner, Stefan
    Department of Prosthetic Dentistry Specialist clinic, Kalmar County Public Dental Service, Kalmar, Sweden.
    Arnebrant, Liselott
    Malmö University, Faculty of Odontology (OD).
    Brudin, Lars
    Department of Clinical Physiology, Kalmar County and Department of Medical and Health Sciences, Linköping University, Kalmar, Sweden.
    Larsson, Christel
    Malmö University, Faculty of Odontology (OD).
    Loss of pulp vitality correlated with the duration of the interim restoration and the experience of the dentist: A retrospective study2023In: The Journal of prosthetic dentistry (Print), ISSN 0022-3913, E-ISSN 1097-6841, Vol. 130, no 6, p. 833-839, article id S0022-3913(21)00698-3Article in journal (Refereed)
    Abstract [en]

    STATEMENT OF PROBLEM: The second most common biological complication in fixed prosthodontics is loss of pulp vitality, which may lead to restoration loss. While reasons for loss of pulp vitality are unclear, 2 potential contributing factors, duration of the interim restoration and operator experience, have not been fully investigated.

    PURPOSE: The purpose of this retrospective study was to investigate whether the duration of the interim restoration or the experience of the dentist was correlated with loss of pulp vitality.

    MATERIAL AND METHODS: Fixed prosthetic restorations placed between 2005 and 2012 were retrospectively analyzed. Abutment teeth supporting single-unti or multiunit restorations were evaluated regarding loss of pulp vitality. The Mann-Whitney U test and simple logistic regression were used, with α=.05 for the subsequent multiple logistic regression. The experience of dental professionals was defined by the number of treatments performed and coupled with failure rate by using an analysis of variance.

    RESULTS: One hundred seventy-four dentists made 15 879 restorations, of which 1136 failed during the observation period, a failure rate of 7.2%. Two hundred fifty restorations were randomly selected from the failed restorations, and a corresponding 250 restorations were randomly selected from nonfailed restorations for the control group. Increased duration with interim replacement was linked to a higher risk of loss of pulp vitality (P<.001). Failure rate in the dentist group varied from 0% to 100%. No significant differences in failure rate were found among dentists who did few restorations and those who performed larger numbers of restorations.

    CONCLUSIONS: The results of the present study suggest that operator experience does not affect failure rate. However, extended time with an interim restoration was a contributing factor to the loss of pulp vitality.

  • 8. Rayyan, Mohammad M.
    et al.
    Aboushelib, Moustafa
    Sayed, Nagwa M.
    Ibrahim, Ahmed
    Jimbo, Ryo
    Malmö högskola, Faculty of Odontology (OD).
    Comparison of interim restorations fabricated by CAD/CAM with those fabricated manually2015In: The Journal of prosthetic dentistry (Print), ISSN 0022-3913, E-ISSN 1097-6841, Vol. 114, no 3, p. 414-419Article in journal (Refereed)
    Abstract [en]

    Statement of problem. Interim restorations represent an essential treatment step; however, the optimal resin material for long-term interim restorations requires investigation. Purpose. The purpose of this in vitro study was to compare the color stability, water sorption, wear resistance, surface hardness, fracture resistance, and microleakage of computer-aided design/computer-aided manufacturing-(CAD/CAM) fabricated interim restorations with those of manually fabricated interim restorations. Material and methods. Epoxy replicas were made from a prepared maxillary first premolar. On the replicas, interim crowns were fabricated and divided into the following groups: CAD/CAM poly(methyl methacrylate) (PMMA) blocks (CC), autopolymerizing temporary resin (AP), automix temporary resin (AM), and thermoplastic resin (TP). After cementation, all specimens were subjected to thermocycling and dynamic fatigue. The CIE Laboratory color coordinates were then recorded before and after immersion in coffee, tea, carbonated cola, and red wine. Water sorption was evaluated by using an immersion technique. Wear resistance was measured in a surface abrasion device. Vickers microhardness was measured on polished specimens. Fracture resistance was evaluated by axial loading with a universal testing machine. Marginal dye penetration was evaluated by sectioning the interim restorations after immersion in methylene blue (alpha=.05). Results. Colorimetric analysis revealed a large degree of color alteration (SE) in the manually fabricated interim restorations: AP = Delta E of 6.7 +/- 2); AM = Delta E of 7.1 +/- 1.5), and TP = Delta E of =5.4 +/- 3.1. The CC group demonstrated color stability (Delta E=2.1 +/- 0.2). CAD/CAM interim restorations demonstrated significantly lower water sorption, higher wear resistance, higher surface hardness, and significantly higher fracture resistance (1 289 +/- 56N) compared with manually fabricated interim restorations (AP=996 +/- 45, AM=899 +/- 37, and TP=1179 +/- 41). The stereomicroscopic examination of sectioned specimens demonstrated the absence of dye penetration in all tested specimens. Conclusions. CAD/CAM interim crowns presented stable physical and mechanical properties and may be used for long-term interim restorations.

  • 9.
    Rutkunas, Vygandas
    et al.
    Vilnius University, Vilnius, Lithuania.
    Dirse, Julius
    Vilnius University, Vilnius, Lithuania.
    Kules, Daniel
    Vilnius University, Vilnius, Lithuania.
    Mischitz, Ingrida
    Medical University of Graz, Graz, Austria.
    Larsson, Christel
    Malmö University, Faculty of Odontology (OD).
    Janda, Martin
    Malmö University, Faculty of Odontology (OD).
    Misfit simulation on implant prostheses with different combinations of engaging and nonengaging titanium bases. Part 2: Screw resistance test2024In: The Journal of prosthetic dentistry (Print), ISSN 0022-3913, E-ISSN 1097-6841, Vol. 131, no 2, p. 262-271, article id S0022-3913(22)00286-4Article in journal (Refereed)
    Abstract [en]

    STATEMENT OF PROBLEM: Prosthesis fit is 1 of the main factors influencing the success and survival of an implant-supported screw-retained restoration. However, scientific validation of the performance of engaging and nonengaging components in a fixed partial denture (FPD) and the effect of their combinations on the fit of FPDs is lacking. The screw resistance test has been used for the fit assessment of screw-retained FPDs. However, objective assessments by using analog and digital devices are now available.

    PURPOSE: The purpose of this in vitro study was to investigate the effect of engaging and nonengaging components on the fit of screw-retained frameworks, supported by 2 conical connection implants with simulated vertical and horizontal misfits, by performing 2 different screw resistance tests (analog and digital).

    MATERIAL AND METHODS: Thirty 2-implant-supported bar-shaped zirconia frameworks cemented on two 2-mm titanium bases were fabricated and divided into 3 groups (n=10) according to different abutment combinations: both engaging, engaging and nonengaging, both nonengaging. The fit of each framework was tested on the control cast and on 6 definitive casts simulating 50-, 100-, and 150-μm vertical and 35-, 70-, and 100-μm horizontal misfit levels. The abutment screws were tightened on each implant, and the screw rotation angle was measured both digitally, with a custom-made digital torque wrench and a computer software program, and conventionally, with an analog torque wrench and protractor. Clearly ill-fitting specimens were excluded. The data were statistically analyzed by 1-way analysis of variance (ANOVA) and the Tukey post hoc test (α=.05).

    RESULTS: Both engaging specimens on the 100-μm horizontal misfit group and on all vertical misfit groups were clearly ill-fitting and excluded. Statistically significant differences among groups with different combinations of abutments were found (P<.05). The engaging abutments had a higher angle of rotation than the nonengaging abutments on all casts. In the horizontal misfit group, both engaging specimens had the highest angle of rotation, followed by engaging and nonengaging and both engaging specimens. In the vertical misfit group, the engaging and nonengaging specimens had the highest angle of rotation on the side of the engaging abutment. The angle of rotation increased with the increasing level of misfit.

    CONCLUSIONS: Both nonengaging frameworks showed superiority in misfit tolerance, as the angle of rotation was lower than that of the engaging and nonengaging and both engaging frameworks. Conventional and digital torque wrenches showed similar results.

    Download full text (pdf)
    fulltext
  • 10.
    Rutkunas, Vygandas
    et al.
    Department of Prosthodontics, Institute of Odontology, Faculty of Medicine, Vilnius University, Vilnius, Lithuania; and Director, Digitorum Research Center, Vilnius, Lithuania.
    Kules, Daniel
    Department of Periodontology, Faculty of Medicine, Vilnius University, Vilnius, Lithuania; and Researcher, Digitorum Research Center, Vilnius, Lithuania.
    Mischitz, Ingrida
    Department of Dental Medicine and Oral Health, Medical University of Graz, Graz, Austria.
    Huber, Sandra
    Department of Dental Medicine and Oral Health, Medical University of Graz, Graz, Austria.
    Revilla-León, Marta
    Department of Restorative Dentistry, School of Dentistry, University of Washington, Seattle, Wash; Digital Dentistry, Kois Center, Seattle, Wash.; Department of Prosthodontics, School of Dental Medicine, Tufts University, Boston, Mass.
    Larsson, Christel
    Malmö University, Faculty of Odontology (OD). Faculty of Dentistry, Department of Prosthetic Dentistry, Riga Stradins University, Riga, Latvia.
    Janda, Martin
    Malmö University, Faculty of Odontology (OD).
    Misfit simulation on implant-supported prostheses with different combinations of engaging and nonengaging titanium bases: Part 32024In: The Journal of prosthetic dentistry (Print), ISSN 0022-3913, E-ISSN 1097-6841, article id S0022-3913(24)00044-1Article in journal (Refereed)
    Abstract [en]

    STATEMENT OF PROBLEM: The fit of implant-supported prostheses plays an important role in their mechanical and biological stability. Clinically, the prosthetic fit is typically assessed radiographically, but this method relies on the operator's subjective evaluation. Whether available digital tools could optimize the evaluation of the prosthetic fit is uncertain.

    PURPOSE: The purpose of this in vitro study was to evaluate the influence of an image processing program on the radiographic detection of discrepancies in the active and passive fit of implant-supported prostheses. Two-implant-supported screw-retained prostheses were analyzed by simulating the vertical and horizontal misfits of 3 different implant abutment configurations.

    MATERIAL AND METHODS: Seven casts were fabricated using 2 internal-connection titanium implants: 1 control; 3 with vertical (V) misfit of 50 µm, 100 µm, 150 µm; and 3 with horizontal (H) misfit of 35 µm, 70 µm, 100 µm. Thirty bar-shaped zirconia frameworks were fabricated and divided into 3 groups (n=10) according to their attachment to 2 engaging (E-E), 2 nonengaging (NE-NE), and engaging and nonengaging (E-NE) titanium bases. Digital parallel periapical radiographs were made of each specimen in the passive and active fit situation on each cast (1-screw test), except for the E-E specimens, which were only seated on the control, H35, and H70 casts because the fit on the remaining casts was poor. The mean gray value (MGV) was measured at the chosen regions of interest on the second implant (side B) using the ImageJ software program. Differences in the MGV measurements between the passive and active conditions were tested using a t test (α=.05) and compared the different misfit levels using analysis of variance (1-way ANOVA), followed by the Tukey HSD test (α=.05).

    RESULTS: The highest values for the differences between passive and active fit were found for the V150 and H100 misfit simulations (P<.05). Statistical differences between the MGVs were found with some exceptions: the smallest simulated misfits (H35 and V50) revealed statistically significant MGV differences from the highest simulated misfits (V150, H100) and from the H70 in the groups where an engaging component was present (P>.05). In the horizontal misfit group of NE-NE abutment configuration, H70 revealed no significant difference from the control group cast (P>.05).

    CONCLUSIONS: Measuring MGV differences between passive and active fit could be a promising alternative for detecting 70- to 150-µm gaps in the implant-abutment connection that result from the misfit. However, the procedure was not adequate for detecting <50 µm gaps, cannot be uniformly applied to all types of implant-abutment connections, and requires 2 exposures to X-radiation.

1 - 10 of 10
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf