Longevity of silicate ceramic restorations

The demand for esthetic restorations has resulted in an increased use of dental ceramics as a biocompatible and functionally sufficient alternative to conventional restorative materials. Silicate ceramic restorations are widely used for veneers, inlays, onlays, and crowns in dentistry. Long-term data are of crucial importance to optimize clinical practice. The purpose of the present article is to summarize data of the Innsbruck ceramic evaluation up to 261 months with the focus on longevity and failure characteristics.

Correction of esthetic and biomechanical outcomes after maxillary anterior single dental implant fracture: a case report

Rehabilitation of the single anterior tooth in the esthetic region after a dental implant fracture requires management of contributing biomechanical and/or biological etiologic factors. The multidisciplinary treatment of a fractured maxillary anterior single dental implant with a staged, combined surgical and prosthetic approach is discussed. Alleviation of several, but not all, risk factors eliminated the need for replacement of gingiva with pink porcelain and maintained a stable post implant host complex.

Comparison of two different veneer preparation designs in vital teeth

OBJECTIVE

To compare the clinical performance of two different veneer preparation designs (overlap and nonoverlap) on anterior veneer restorations in vital teeth in a retrospective clinical study.

METHOD AND MATERIALS

In this study, 292 anterior all-ceramic veneer restorations in vital teeth were clinically examined in 74 patients. The preparation designs were categorized by the amount of tooth reduction on the final casts, with 245 in the overlap and 47 nonoverlap group.

RESULTS

After a mean ± SD observation time of 124.25 ± 60.61 months, 20 failures occurred. All failures occurred in the overlap design. Restorations with nonoverlap preparation designs showed significantly fewer failures than restorations with overlap preparation design (P = .018, log-rank).

CONCLUSION

Based on the findings of this study, whenever feasible, a preparation design without incisal overlap is recommended, especially in vital teeth..

Clinical performance of all-ceramic inlay and onlay restorations in posterior teeth

PURPOSE

The aim of this clinical retrospective study was to evaluate the clinical performance and longevity of glass-ceramic onlays and inlays in stress-bearing posterior teeth.

MATERIALS AND METHOD

Five hundred forty-seven posterior teeth in the maxillae and mandibles of 120 patients (46 males, 74 females) were restored with 213 onlays, 38 single-surface inlays, 141 two-surface inlays, and 155 three-surface inlays between 1987 and 2009 at Innsbruck Medical University, Innsbruck, Austria, by two experienced dentists. The restoration sample included 9 (1.6%) nonvital teeth and 40 (33%) patients diagnosed with bruxism. The study population was examined clinically during regularly scheduled maintenance appointments. The risk of failure was determined using Kaplan-Meier survival analyses.

RESULTS

The mean observation periods for onlays and all inlays were 80 ± 34 months and 111 ± 63 months, respectively. Twenty-seven failures were recorded. The estimated survival rates for onlays and all inlays after 5, 10, and 12 years were 98.9% and 98.9%, 92.4% and 96.8%, and 92.4% and 89.6%, respectively. Nonvital teeth showed a significantly higher risk of failure (P < .001). There was no greater risk of failure associated with existing parafunction (bruxism) (P = .408). Restorations on premolars survived longer in the first 15 years than restorations on molars, but no statistical significance was found (P = .913).

CONCLUSION

Glass-ceramic onlays and inlays were demonstrated to be successful in posterior teeth; however, at this time, their efficacy is inferior to that of cast gold restorations.

Surgical resection technique of a fused supernumerary lateral incisor: a clinical report and review of the literature

This case report presents the surgical and restorative management of a fused supernumerary left lateral incisor. The diagnosis was confirmed using conventional radiographs and CT. The case report discusses the value of CT for evaluation of the root relationships and describes the varied morphology associated with supernumerary incisors, the surgical resection technique, partial pulpotomy, and restoration with composite resin after mechanical exposure of the remaining tooth's pulp.

Impact of a prior medical degree on students' dental school performance in Innsbruck, Austria

The purpose of this study was to identify the performance differences between two groups of Austrian dental students (one with a prior medical degree and one without a medical degree) during their dental school training and final dental licensure examination. A specific aim was to determine if having a medical degree is a predictive factor for dental students' scores on the Austrian Dental Admission Test (Austrian DAT), performance in the dental clinic, and scores on final exam. The study consisted of a retrospective analysis of 122 students (thirty-nine with a medical degree and eighty-three without a medical degree) who were enrolled in the Dental Clinic at Innsbruck Medical University, Innsbruck, Austria, between 2001 and 2006. Three performance categories were considered: Austrian DAT results, clinical performance after the first clinical year in dental school, and performance on the final dental licensure examination. Information on students' age, gender, and previous medical degree was collected from official records. Analyses with student's t-test and Pearson's chi-square test revealed that the students with a medical degree had significantly higher Austrian DAT total test scores, grade point averages after the first clinical year, and scores on the final exam. Additionally, those students had significantly better performance on the final exam in prosthodontics and oral and maxillofacial surgery. The linear regression analysis showed that a medical degree had an independent effect on average scores on the final exam, age, and Austrian DAT test scores, while gender showed no statistically significant effect. Overall, the study found that dental students with a prior medical degree had significantly higher Austrian DAT total test scores and performed significantly better in the first clinical year and on the final exam than those without a prior medical degree.

Clinical performance of porcelain laminate veneers for up to 20 years

PURPOSE

The aim of this clinical retrospective study was to evaluate the clinical quality, success rate, and estimated survival rate of anterior veneers made of silicate glass-ceramic in a long-term analysis of up to 20 years.

MATERIALS AND METHODS

Anterior teeth in the maxillae and mandibles of 84 patients (38 men, 46 women) were restored with 318 porcelain veneer restorations between 1987 and 2009 at the Medical University Innsbruck, Innsbruck, Austria. Clinical examination was performed during patients' regularly scheduled maintenance appointments. Esthetic match, porcelain surface, marginal discoloration, and integrity were evaluated following modified California Dental Association/Ryge criteria. Veneer failures and reasons for failure were recorded. The study population included 42 (50.0%) patients diagnosed with bruxism and 23 (27.38%) smokers. The success rate was determined using Kaplan-Meier survival analysis.

RESULTS

The mean observation time was 118 ± 63 months. Twenty-nine failures (absolute: 82.76%, relative: 17.24%) were recorded. The main reason for failure was fracture of the ceramic (44.83%). The estimated survival rate was 94.4% after 5 years, 93.5% at 10 years, and 82.93% at 20 years. Nonvital teeth showed a significantly higher failure risk (P = .0012). There was a 7.7-times greater risk of failure associated with existing parafunction (bruxism, P = .0004). Marginal discoloration was significantly greater in smokers (P ⋜ .01).

CONCLUSION

Porcelain laminate veneers offer a predictable and successful restoration with an estimated survival probability of 93.5% over 10 years. Significantly increased failure rates were associated with bruxism and nonvital teeth, and marginal discoloration was worse in patients who smoked.

Resection of a primary oral malignant melanoma and rehabilitative management using nasolabial flap: a case report

BACKGROUND

The primary malignant melanoma is a rare neoplasm of melanocytic origin in the oral cavity. Only about 1% of all melanomas arise in the oral mucosa and these account for 0.5% of all oral malignancies

CASE REPORT

This report describes an oral malignant melanoma occurring in the right maxilla of a 73-year-old patient. The interdisciplinary management using a nasolabial flap and prosthetic oral rehabilitation procedure is described.

DISCUSSION

The nasolabial flap technique offers the possibility of an immediate reconstruction of the maxillary defect and obviated problems with speech, swallowing, and permitted oral intake. As a supplementary benefit, the resection area can support the prosthetic rehabilitation.

Impact of a novel dental school admission test on student performance at Innsbruck Medical University, Austria

Since the year 2000, prospective dental students at Innsbruck Medical University, Innsbruck, Austria, have undergone both theoretical and practical preadmission exams, called the Dental Admission Test (DAT). The aim of this investigation was to assess the suitability and outcome of this selection practice. Five classes from 2001 to 2005 (N=97; forty-three female, fifty-four male) were retrospectively reviewed. DAT results were compared with student performance, gender, ability to graduate on time, and dropout rates. Furthermore, the influence of a previous medical degree was evaluated. The t-test was used to analyze correlations between the results of the DAT and the following: gender, students who graduated on time, and students who had previously completed a medical degree. Pearson's correlation coefficient (r) was applied to analyze correlations among test scores, age, and students' performance during the first clinical year. Students graduating on time were noted to have significantly better DAT results; students with a previous medical degree showed significantly better grades during their first clinical year. The difference between the performance of male and female applicants on the DAT was not significant. Correlation was found between DAT results and dental school performance (r=-0.462). We conclude that the DAT may reduce dropout rates by excluding applicants unlikely to be successful in practical courses and that DAT scores are a reliable tool to predict student performance during the first clinical year of dental school in Innsbruck.

Quality of impressions using hydrophilic polyvinyl siloxane in a clinical study of 249 patients

PURPOSE

This study aimed to evaluate the clinical success of a hydrophilic polyvinyl siloxane impression material for fixed dental restorations under various clinical conditions.

MATERIALS AND METHODS

A total of 1,466 preparations for fixed restorations in maxillary and mandibular anterior and posterior teeth were evaluated. The study contained inlay, onlay, crown, veneer, post, and adhesive-wing preparations and implants for gold, porcelain-fused-to-metal, and ceramic restorations. The preparation finish line relative to the crest of the marginal gingiva, type of restoration, and position of the teeth were recorded. Three categories were established to rate impression quality: perfect impressions, with an absence of any voids or bubbles and perfect reproduction of the preparation finish line, were rated Criteria I; acceptable impressions, with minimal defects (< or = 2 mm) not involving the preparation finish line, were rated Criteria II; and unacceptable impressions, with larger voids or bubbles (> 2 mm) or defects involving the preparation finish line, were rated Criteria III.

RESULTS

Overall, 96.86% of the final impressions were clinically acceptable, 89.43% of which were rated Criteria I and 7.43% of which were rated Criteria II. Only 3.14% of the impressions were unacceptable and rated Criteria III. A significant influence on impression quality was found when the preparation finish line was more than 2 mm subgingival (P < .004), as well as when a beveled preparation was used (P < .004). The position of the teeth (P > .404) had no significant effect.

CONCLUSION

Surface-activated polyvinyl siloxane impression material offers high predictability to avoid bubbles and voids in the final impression.