1,720,980 research outputs found
Comparison of the Accuracy and Time Efficiency of Two Different digital Impressions of Single Tooth Implant Treatments
No full textObjective: Over the last decades, techniques and materials have evolved with the improvement in digital technology. Computer-aided impressions have been transforming the dental implant field with these developments. The aim of this in vivo study was to compare the accuracy and time efficiency between two intraoral scanning systems in single tooth implant treatment. Methods: 10 patients with single tooth bone level implant (Straumann, Basel, Switzerland) received one conventional impression with polyvinyl siloxane and three scans with 2 different intra-oral scanners (CEREC AC Omnicam and Straumann CARES IOS). The time required for the impressions was measured at this stage. The casts obtained from conventional impressions were scanned as the master model to evaluate accuracy. Digital impression files were analyzed using a software (Geomagic Control). Independent Samples Test was performed for trueness and precision. One-way ANOVA was executed for time efficiency. Least significant difference test for post hoc comparison was conducted (p<0.05). Results: The differences between the two systems regarding trueness and precision were not statistically significant (P>0.05), but a statistically significant difference was found in the time efficiency (P<0.05). CEREC AC showed the lowest mean values in time measures. Conclusions: There was no difference regarding accuracy in comparison between CEREC AC Omnicam and CARES. CEREC AC Omnicam was found to be superior in terms of time efficiency in comparison to CARES and conventional impressions
Clinical performance of pressable glass-ceramic veneers after 5, 10, 15, and 20 years: A retrospective case series study
No full textObjectives To evaluate the long-term clinical performance and survival rate of pressable lithium-disilicate glass-ceramic veneers (LDSVs). Materials and Methods A total of 413 LDSVs were bonded to anterior and posterior teeth by three experienced clinicians between 1998 and 2012. The LDSVs were examined for color/ esthetic match of the glass-ceramic surface (esthetic evaluation), fracture rate, marginal discoloration (staining of the luting cement), and marginal integrity (including caries, clinical evaluation). For clinical and esthetic evaluations, the modified United States Public Health Services (USPHS) score was used in this study. The success rate was determined with a Kaplan-Meier survival analysis. Results The mean observation time was 11.33 +/- 4.85 years. There was no loss to follow-up, all restorations were accounted for in the final analysis. The probability of survival of the 413 veneers was 98% after 5 years, 95% at 10 years, 91% at 15, and 87% at 20 years, indicating a very low clinical failure rate. Of the 413 restorations, complications were occurred in 15 (3.63%) of all restorations, and fractures and debonding in 6 (1.45%) and 9 (2.18%), respectively. Conclusions The LDSVs showed high survival rate and very good results for color match and anatomic form and marginal integrity in the long-term analysis. Clinical Significance The long-term performance of LDSVs can be considered as highly favorable when carefully planned
The Clinical and Radiologic Outcomes of Early Loaded Implants After 5 Years of Service
No full textPurpose: To evaluate the 5-year results of the clinical and radiographic outcomes of three types of early loaded implants. Materials and Methods: Seventy-five implants were placed in the posterior mandible or maxilla in 30 patients. Three types of implants (Straumann SLActive, Astra OsseoSpeed, and Thommen Implant System) were used. Definitive restorations were made after 8 weeks of implant placement. The radiographs were taken at the placement of the prosthesis, at 6 months, and at 1- and 5-year follow-ups. Clinical and radiologic data were evaluated for all types of implants. The Wilcoxon signed rank test, least significant differences, and Mann-Whitney U were used to test for statistically significant differences (P < .005). Results: Twenty-four patients and 62 implants were evaluated after 5 years. The mean marginal bone loss was 0.20 +/- 0.40 mm, 0.21 +/- 0.05 mm, and 0.25 +/- 0.36 mm after 1 year and 0.32 +/- 0.22 mm, 0.31 +/- 0.26 mm, and 0.42 +/- 0.36 mm after 5 years for the Straumann, Astra, and Thommen groups, respectively. After 5 years, the mean peri-implant probing depth level was 1.75 +/- 0.49 mm, 1.87 +/- 0.48 mm, and 1.92 +/- 0.57 mm for the Straumann, Astra, and Thommen groups, respectively. No peri-implantitis was detected after 5 years of loading. Conclusion: All groups of implants showed a stable peri-implant probing depth and marginal bone level. The survival rate was high and bone loss was low at 5 years; thus, early loading may be a useful procedure that allows reduction in treatment time
Two-body wear of occlusal splint materials against different antagonists
No full textBackground This study aimed to demonstrate that the material of the occlusal splint can be chosen according to the needs of individual patients and contribute to the knowledge of the wear rate of these materials. Methods In this study, four occlusal splint materials (Sr Ivocap Heat Cured, Valplast, SR Ivocap Elastomer and Eclipse) and three antagonists (natural tooth enamel, inCoris TZI and IPS e.max Press ceramic materials) were used. Each wear test was performed using a chewing simulator (n = 16; test load: 50 N; number of cycles: 10,000, 20,000 and 30,000; continuous rinsing with water at 30 degrees C for the wet condition). The Shapiro Wilk test was used for normal distribution suitability. Antagonist on average wear quantities both main effects and interactions of material, cycle and condition factors were investigated by Univariate variance analysis. Multiple comparisons were examined using the Games-Howell test. Results There was a statistically significant effect of the difference in materials on the amount of wear (p < 0.001). Furthermore, there was a statistically significant difference among the mean values of all materials (p > 0.001). The highest mean value was obtained with Eclipse (0,318 mu m(3)), and the lowest mean value was obtained with Valplast (0,134 mu m(3)). Conclusion Our study found differences in the in vitro wear rate among various occlusal splint materials
Fracture Resistance of Porcelain Laminate Veneers
Full text linkIn recent dentistry, laminate veneers have gained widespread utilization as a conservative treatment option of unaesthetic anterior teeth. The continued development of dental ceramics offers clinicians many options for creating highly aesthetic and functional porcelain veneers. The behavior of these restorations against the functional loads plays an important role in their success. Many studies have evaluated the fracture resistance of laminate veneers in vitro and in vivo
Clinical and Radiographic Evaluation of Early Loaded Maxillary Anterior Implants: Three-Year Follow-up
No full textThe aim of this study was to evaluate clinical and radiologic results up to 3 years in patients treated with early loading of anterior implants supporting single-tooth all-ceramic restorations. Twenty-four patients were treated with 29 screw-type implants in the anterior maxilla. The implants were evaluated by clinical and radiographic parameters. Clinical parameters Plaque Index (PI), Sulcus Bleeding Index (BI), peri-implant probing depth (PD), and marginal bone loss (MBL) were recorded. At the recall examinations, all implants were successfully integrated, demonstrating healthy peri-implant soft tissues as documented by standard clinical parameters. No biologic complications were observed. There was no statistically significant increase in MBL between the baseline and recall stages (P >.05). Early loaded maxillary anterior implants supporting single-tooth restorations reveal successful clinical and radiographic outcomes when treatment steps were performed
Comparing Volumetric Dimensional Stability and Accuracy of Newly Formulated Polyvinyl Siloxanether, Polyvinyl Siloxane and Polyether Impression Materials Using Micro-Computed Tomography
No full textObjective: The purpose of this study was to compare volumetric dimensional accuracy and stability of polyvinylsiloxane, polyether and new formulated polyvinylsiloxanether impression materials by using micro-computed tomography. Methods: A total of 42 impressions were made of stainless steel metal dyes. Polyvinylsiloxane, Polyether and Polyvinylsiloxanether impressions were taken for volumetric dimensional accuracy and stability to measure by Micro-computed tomography (mu CT). Impression materials were measured for dimensional stability after the impression was taken, 24 hours later and 144 hours later. For dimensional accuracy 21 impressions and 21 stone models of these impressions were measured. One-way analysis of variance was be used to test for statistically significant difference within groups and Tukey's test was be used to test for across groups with a significance value of p < 0.05. Results: After polymerization, although polyether impression negative was shown to have the highest volumetric expansion, the highest shrinkage was observed in the same group after pouring to dental stone. Stone model of the polyether was observed as the most accurate value of volume in comparison to the master model. The lowest volumetric dimensional change was observed in polyvinylsiloxanether at day 1 (-0.004 +/- 0.001%) and the highest change was observed in polyether at day 7 (-0.052 +/- 0.004%). Conclusion: From the standpoint of volumetric accuracy and stability, all three elastomeric impressions are acceptable and mu CT is a useful tool for assesments of volumetric dimensional changes
Clinical Evaluation of Three Types of CAD/CAM Inlay/Onlay Materials After 1-Year Clinical Follow Up
No full textObjective: To evaluate the clinical performance and the marginal adaptation of inlay/ onlay restorations made of lithium of a new lithium disilicate strengthened, lithium alumino-silicate glass-ceramic (LAS) material compared with a conventional lithium-disilicate glass-ceramic (LDS) and new-generation polymer-based CAD/CAM resin composite (CS) materials over one year. Materials and methods: Seventy-five inlay-onlay restorations were placed in 35 patients. The restorations were assigned and randomized to three groups as LDS, LAS, and CS. Clinical evaluations were performed after one week, six months, and one year after the cementation, according to the modified United States Public Health Services (USPHS) criteria. The marginal quality analyses of 21 samples (n=7) were assessed under a scanning electron microscope. The data were analyzed by using Friedman, Wilcoxon Signed Ranks, Chi-square and Paired t-tests (p<0.05). Results: No statistically significant difference (p>0.05) was found between groups in the modified USPHS, gingival index, and plaque index evaluations, and the total success rate was 100% for three groups after one year. Following SEM evaluations in all groups, continuous margin percentages were decreased, but these results were not statistically significant (p>0.05). Conclusions: Lithium disilicate-strengthened lithium aluminosilicate glass-ceramics can be considered a reliable material for an option for posterior onlay/inlay restorations
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