Yasemin Kulak-Ozkan

Fracture Resistance of Manually and CAD/CAM Manufactured Ceramic Onlays

PURPOSE This in vitro study aimed to evaluate fracture resistance in lithium disilicate onlays fabricated with IPS e.max Press and IPS e.max CAD systems and luted with different adhesive cements. MATERIAL AND METHODS Fifty maxillary first molars were prepared using a mesio-occluso-disto-lingual onlay cavity model. Ten onlays from each group were cemented using etch-and-rinse adhesives and high-viscosity composite resin cement, and 10 were cemented with self-adhesive, dual-curing universal resin cement. Fracture resistance was measured. RESULTS Significant differences were observed between resin cements (p < 0.05) and between materials (p < 0.05), but the interaction of these variables did not produce a significant difference. The fracture resistance of pressable ceramics was significantly higher than that of CAD/CAM onlays (p < 0.05), and Syntac Variolink was significantly higher than that of Multilink Sprint (p < 0.05). CONCLUSION All groups showed clinically acceptable fracture strength results. According to the study, both the onlay fabrication system and adhesive cements can be a viable treatment option.

Retrospective analysis of prosthetic complications of implant-supported fixed partial dentures after an observation period of 5 to 10 years.

PURPOSE The purpose of this study was to evaluate the incidence of the most common technical problems with implant-supported fixed partial dentures (FPDs) and to assess the survival and success rates (event-free survival) after 5 to 10 years of function. MATERIALS AND METHODS All of the implants evaluated in this study were from a single manufacturer (Institut Straumann). Follow-up examinations were scheduled 1 week after suprastructure placement, 6 months later, and annually thereafter. Prosthesis-based data on survival/failure rates and technical complications were analyzed. RESULTS In 95 partially edentulous patients, 231 Straumann implants were placed and restored with 177 implant-supported prostheses (125 single crowns, 18 splinted crowns on two adjacent implants, and 34 three-unit FPDs). One hundred thirty one solid abutments and 100 synOcta abutments were inserted. The survival rate of prostheses supported by implants was 97.7%. The prosthetic success rate (event-free survival) was 96.05%. After an observation period of 5 years, the cumulative incidence of screw loosening was 0%. Fracture of the veneering porcelain occurred in 3.95% of all restorations. Fractures of the superstructure framework were not observed. The overall incidence of complications after 5 years was highest for splinted crowns, which showed the lowest success rate (94.4%), followed by three-unit FPDs (96%) and single crowns (98.4%). CONCLUSIONS Single-unit restorations or short-span FPDs supported by both synOcta and solid abutments on Straumann implants showed low rates of technical complications, the most common being fracture of the veneering porcelain.

Esthetic Outcome Evaluation of Maxillary Anterior Single-Tooth Bone-Level Implants with Metal or Ceramic Abutments and Ceramic Crowns

PURPOSE The aim of this study was to evaluate the treatment outcome of implants placed in the maxillary anterior segment. MATERIALS AND METHODS Patients were treated with bone-level implants (Straumann Bone Level Implant, Institut Straumann) that supported all-ceramic single crowns and were followed for 2 to 4 years. Titanium or ceramic abutments were used according to the quality of the soft tissue at each site. Esthetic parameters were recorded to assess treatment outcomes. Pink esthetic scores (PES) and white esthetic scores (WES) were used to evaluate the esthetic outcome of anterior single-tooth implant-supported crowns. Patient satisfaction was also evaluated by means of a questionnaire. RESULTS Fifty-five implants were placed in 47 patients. At the recall examinations, all implants were confirmed to have successfully integrated and demonstrated healthy peri-implant soft tissues, as documented by generally accepted clinical parameters. Overall, the esthetic results were considered favorable, and there were no significant differences between restorations with ceramic or titanium abutments. WES values were slightly superior to PES values. None of the implants had mucosal recession. CONCLUSION Objective and subjective evaluation of maxillary bone-level implants in the esthetic zone yielded satisfactory results. Pleasing esthetic outcomes and stable facial soft tissues were achieved.

Clinical and Radiographic Evaluation of Early Loaded Maxillary Anterior Single-Tooth Bone-Level Implants

PURPOSE The aim of this study was to evaluate the clinical and radiographic outcomes of early loaded platform-switched implants in the anterior maxilla. MATERIALS AND METHODS In this study, patients were treated with implants that supported all-ceramic single-tooth crowns and were followed for 2 to 4 years. Implants were evaluated on the basis of clinical and radiographic parameters, including Plaque Index, Sulcus Bleeding Index, peri-implant probing depths (PDs), Papilla Index, soft tissue recession, and marginal bone levels. Statistical analyses were performed. RESULTS Fifty-five implants were placed in 47 patients. At the recall examinations, all implants had successfully integrated, demonstrating healthy peri-implant soft tissues as documented by standard clinical parameters. At the time of recall, 7 implants had been followed for 4 years, 30 implants for 3 years, and 18 implants for 2 years. Plaque accumulation scores of 2 and 3 were not noted at any point during the study. At baseline, the mean PD was 2.1 ± 0.6 mm, at 2 years it was 2.2 ± 0.6 mm, at 3 years it was 2.2 ± 0.6 mm, and at 4 years (7 implants), the mean PD was 1.9 ± 0.4 mm. There were no statistically significant differences between time intervals. Complete papilla fill was seen for 49 implants. All implants showed less than 0.5 mm of marginal bone loss; mean bone loss at the time of final recall was 0.12 ± 0.22 mm. Seven implants showed an increase in the level of bone contact. There were no statistically significant differences over time. CONCLUSION Bone-level implants with a platform-switched design are a successful treatment modality for anterior single-tooth implants.

Marginal and internal adaptation of different superstructure and abutment materials using two different implant systems for five-unit implant-supported fixed partial dentures: an in vitro study.

PURPOSE To evaluate the marginal and internal adaptation of five-unit implant-supported fixed partial dentures with different superstructure and abutment materials with two different implant systems. MATERIALS AND METHODS Two mandibular epoxy resin models (one for each implant system) were fabricated, and implants were inserted in the canine, first premolar, and first molar regions. Thirty impressions of each model were then made. The 30 models of each group were divided into three subgroups: group 1, titanium abutment with metal (nickel-chromium) framework; group 2, titanium abutment with zirconium framework; and group 3, zirconium abutment with zirconium framework. The replica technique was used to examine the marginal and internal gap values. For each restoration, 20 measurements were performed, and the data were evaluated statistically using analysis of variance and the least significant difference post hoc test. RESULTS The highest values for internal adaptation were observed at the occlusal surface in all groups. There were statistically significant differences in marginal measurements between subgroups. The smallest gaps were found in group 1 (79.361 μm), and the largest gaps were found in group 3 (131.242 μm). CONCLUSIONS In this study, marginal and internal gap measurements were 79 to 131 μm. The marginal discrepancy of the tested materials could be considered clinically acceptable.

In Vitro Comparison of Marginal and Internal Fit of Press-on-Metal Ceramic (PoM) Restorations with Zirconium-Supported and Conventional Metal Ceramic Fixed Partial Dentures Before and After Veneering.

PURPOSE To compare marginal and internal fit between 3- and 4-unit press-on-metal (PoM) ceramic, zirconia-supported, and conventional metal ceramic fixed partial dentures (FPDs) before and after veneering. MATERIALS AND METHODS Ten pieces for each 3- and 4-unit MC, IPS InLine PoM, and IPS e.max ZirCAD/Zir Press FPDs were produced. Cross-sections from silicone replicas were examined and measured with a light microscope. Occlusal, axial, intermarginal, and marginal mean adaptation scores of cross-sectioned replicas and means of measurements obtained from 4 sites were calculated independently. RESULTS Mean values for molars were 78.44 ± 32.01 μm (MC), 89.84 ± 29.20 μm (PoM), and 85.17 ± 28.49 μm (Zir). Premolar values were 76.08 ± 27.92 μm (MC), 89.94 ± 23.49 μm (PoM), and 87.18 ± 28.25 μm (Zir). No difference existed between the means of 3- and 4-unit FPDs except the molar-intermarginal region. The mean value of 4-unit FPDs (93.88 ± 25.41 μm) was less than the 3-unit FPDs (103.68 ± 24.55 μm) at the molar-inter marginal region. A gap increase was observed in all sites except the molar-axio-occlusal region after veneering. According to the mean difference, gap increases at the molar-marginal, molar-intermarginal, and premolar-intermarginal regions were statistically significant. A statistical difference was found at the molar-marginal region for 4-unit MCR (p = 0.041) and 4-unit PoM FPDs (p = 0.042) before and after veneering. Gap increase after veneering of 4-unit metal ceramics at molar-intermarginal, premolar-marginal, and premolar-intermarginal regions (p = 0.020; p = 0.015; p = 0.004) was significant. CONCLUSION The gap measurements of the IPS InLine PoM and IPS e.max ZirCAD/Zir Press groups were all clinically acceptable. No studies on marginal and internal fit in the IPS InLine PoM system have been published to date. This study should be supported with future studies. No significant increase was observed after press-veneering the IPS e.max ZirCAD frameworks with an IPS e.max ZirPress material; therefore, we recommend the use of this combination.

Minimally invasive veneers: current state of the art.

Ceramic veneers are considered a conservative solution for patients requiring improvement of the shape, color, or position of their anterior teeth. Ceramic veneers have been extensively and successfully used to mask intrinsic staining, to give the appearance of straightening, and to correct minor malformations of anterior teeth without the removal of substantial amounts of sound tooth substance. The current literature was reviewed to search for the most important parameters determining the long-term success and correct application of ceramic veneers.

The Effect of Different Restorative and Abutment Materials on Marginal and Internal Adaptation of Three‐Unit Cantilever Implant‐Supported Fixed Partial Dentures: An In Vitro Study

PURPOSE Passive fit is generally assumed to be a significant prerequisite for long-term implant success. The aim of this study was to evaluate the precision fit of three-unit implant-supported fixed partial dentures with different restorative and abutment materials on two implant systems: the Straumann and Astra Tech. MATERIALS AND METHODS Two mandibular epoxy resin models (one for each implant system) were fabricated, and two implants were inserted at the first and second molar region. Poly(vinyl siloxane) impression material was used to make the dental impression. For each implant system, fifteen models were fabricated, and each group was divided into three subgroups (group 1: titanium abutment with metal framework, group 2: titanium abutment with zirconium framework, group 3: zirconium abutment with zirconium framework). The replica technique was used to examine the marginal and internal gap values. For each restoration, 20 measurements were performed, totaling 1200 measurements for all groups. Data were evaluated statistically using ANOVA and LSD post hoc test (p < 0.05). RESULTS The highest values at internal adaptation measurements were found at the occlusal surface for all groups. When the mean values of the marginal measurements were assessed, the lowest measurements were found in group 3 (51.416 μm), and the highest values were found in group 1 (79.394 μm). There were statistically significant differences between subgroups for marginal measurements (p < 0.05). CONCLUSIONS As included in our study, marginal measurement values were found to be 46 to 87 μm. The marginal discrepancy of the tested materials could be considered clinically acceptable.