The International Journal of Prosthodontics, 01/2012

Purpose: The aim of this study was to describe differences in denture wearing by individuals among the older segment of different European populations. Materials and Methods: Data from the Survey of Health, Ageing, and Retirement in Europe was used to estimate a series of multivariate logistic regression models to analyze differences in self-reported denture wearing by individuals older than 50 years of age from 14 European countries (P .05). Results: Comparably high population proportions with dentures prevail in Austria, Ireland, Poland, Belgium, The Netherlands, and Germany. Median levels are observed in Czechia and Spain. Relatively low levels of denture wearing are reported from elderly residents in Sweden, Greece, Italy, Denmark, Switzerland, and France. Conclusion: There are considerable differences in denture wearing by individuals from the older segment across various European populations. Future research is encouraged to detect the precise causes of such variations in prosthetic care.

The aim of this study was to evaluate the time-dependent clinical efficacy of anterior and posterior zirconia fixed partial dentures (FPDs). A convenience sample of 28 patients, each wearing 1 FPD, was recalled annually throughout a 6-year follow-up period (mean: 6.5 years). Four patients did not participate in the study (dropouts), and 24 FPDs were in use during the observation period. The cumulative survival and success rates were 88.9% and 81.8%, respectively. Fixed prostheses with zirconia frameworks may be regarded as acceptable alternatives to metal-ceramic anterior and posterior FPDs.

Purpose: A completely edentulous or partially edentulous maxilla involving missing anterior teeth may impact speech production and lead to reduced speech intelligibility. The aim of this study was to prospectively evaluate the effect of a dental prosthetic rehabilitation on speech intelligibility in patients with a toothless or interrupted maxillary arch by means of an automatic, standardized speech recognition system. Materials and Methods: The speech intelligibility of 45 patients with complete tooth loss or a loss including missing anterior teeth in the maxilla was evaluated by means of a polyphone-based automatic speech recognition system that assessed the percentage of correctly recognized words (word accuracy). To replace inadequate maxillary removable dentures, 20 patients from the overall sample had been rehabilitated with complete dentures and 25 patients with telescopic prostheses. Speech recordings were made in four recording sessions (with and without existing prostheses and then at 1 week and 6 months after placement of newly fabricated prostheses). Results: Significantly higher speech intelligibility was observed in both patient groups compared to the original results without the dentures inserted. After 6 months of adaptation, both groups had reached a level of speech quality that was comparable to the healthy control group. However, patients receiving new telescopic prostheses showed significantly higher levels of speech intelligibility compared to those receiving new complete dentures. Within 6 months, speech intelligibility did not significantly improve from the level found 1 week after insertion of new prostheses for both groups. Conclusion: Patients benefit from the fabrication of new dentures in terms of speech intelligibility, regardless of the type of prosthesis. However, telescopic crown prostheses yield significantly better speech quality compared to complete dentures.

This article has been withdrawn from publication.

Purpose: The aim of this research was to test the hypothesis that patients' attitudes toward their body affect their capacity to accurately select their existing natural tooth color. Materials and Methods: Standard validated psychologic assessments were used to determine a person's perception of body image and experience. Oral images were compared with the patients' perceptions of their natural tooth color, which were then compared with the actual tooth color judged by a dental professional. Results: For the vital body dynamic and disliking body experience subscales, women exhibited a significantly more negative attitude toward their bodies than men (P = .000). Patients with a negative attitude toward their body tended to choose a lighter tooth color. The correlation between patients' and the testing physician's choices of color was r = 0.540 for women and r = 0.746 for men. Conclusions: Unhappiness with body image and experience results in poor perception of a patient's own oral image, which in turn results in a patient perceiving that his or her natural tooth color is lighter than that judged by a dental professional. This has clinical implications when trying to achieve patient satisfaction with dental prostheses.

The purpose of this study was to compare the accuracy of casts made using three different impression techniques to obtain an accurate definitive cast for fabrication of multiple-implant prostheses. Twelve experimental groups were formed combining the following conditions: three impression techniques, two impression materials, and two cast materials. The main effects of the three factors were analyzed by three-way analysis of variance using the full factorial general linear model between factors. The results showed that there were no significant differences in mean values for the transferred dimensions between the control and experimental groups. None of the measurements in the horizontal plane of the definitive casts demonstrated significant differences among the impression techniques with different impression and cast materials (P > .01).

The host-implant interface is remarkably enduring given the functional and biologic challenges it faces, and our success in assisting patients to lead better lives because of implant biotechnology is the envy of many other health care practitioners. It is therefore vital that dentists accept that clinically significant marginal bone loss is uncommon and that implant failure is rare. In this paper, important elements regarding why implants experience marginal bone loss, why implants may fail as a result of such bone loss, and how to describe the continuum of bone loss with respect to patient-mediated outcomes are outlined.

Purpose: Fracture is a frequent complication of resinous prostheses. The purpose of this study was to evaluate the effect of thickness on flexural strength of a resinous prosthesis containing a prosthetic tooth. Materials and Methods: Beam-shaped specimens 65-mm long, 12-mm wide, and 1, 2, 3, 4, or 6 mm in thickness were made from high-impact strength polymethyl methacrylate denture base material, each containing a resin-based molar prosthetic tooth at the center of the beam. A group of 3-mm-thick specimens without a prosthetic tooth (n = 7) were also made. Specimens were aged artificially, loaded in three-point flexure, examined fractographically, and analyzed. Results: The 1- and 2-mm-thick beams underwent considerable deformation at low loads. Maximum loads varied considerably from 0.6 kg (1-mm beams) to 38 kg (6-mm beams). The 3-, 4-, and 6-mm beam groups all underwent brittle fracture, with mean relative flexural strengths of approximately 73 MPa. Denture teeth reduced the relative flexural strength of resin beams by 0.7×. Fracture initiation sites were generally at tiny surface defects, but did not directly involve denture teeth. Denture resin fracture toughness was 3.2 MPa m1/2, and modulus of rupture was 104 MPa. Conclusion: Denture teeth substantially decreased the strength of resinous beams. Increased thickness markedly increased the load-bearing capacity of resinous beams containing denture teeth. Beams less than 2 mm in thickness with denture teeth were weakened substantially more than comparable beams of 2 mm or more in thickness. Surface finish was of critical importance. Fracture toughness was calculated fractographically, facilitating future forensic examination of clinically failed resinous prostheses.

Ehlers-Danlos syndrome (EDS) encompasses six types of hereditary connective tissue disorders, with skin hyperextensibility, joint hypermobility, and connective tissue fragility as the main findings. Oral health is also affected, sometimes including periodontitis and tooth loss. This is the first report on dental implant treatment for patients with hypermobility or classic EDS. Five female patients aged 19 to 68 years who tolerated treatment under local anesthesia and did not require bone augmentation were enrolled in the study and received 16 implants. They were observed for 2 to 12 years. No implants were lost, bone loss was minimal, and all patients were pleased with the treatment outcomes.

This study evaluated secondary caries and periodontal conditions associated with metal (MCs) and composite resin copings (RCs) of abutment teeth for overdentures. The rates of secondary caries and periodontal problems in 70 root copings (41 MCs, 29 RCs) in 35 patients were retrospectively investigated for a period of 6.9 years. Statistical analysis was performed using chi-square tests and logistic regression (P .05). No significant differences in secondary caries or periodontal conditions were detected between MCs and RCs. These results suggest that RCs and MCs can be used as root copings of abutment teeth for overdentures.

The aim of this study was to compare data on design and fabrication methods of removable partial dentures (RPDs) in two major cities in Greece. A questionnaire was sent to 150 randomly selected dental technicians. The participation rate was 79.3%. The anterior palatal strap, the lingual bar, and the Roach-type clasp arm designs were preferred. Half of the RPDs fabricated were retained using precision attachments. Differences between the two cities were observed in types of major maxillary connectors used, types of attachments and impression materials used, as well as the design of distal-extension RPDs. Postdoctoral education was found to have an impact on RPD fabrication. Despite the differences observed, design and fabrication of RPDs followed commonly used principles.

Purpose: The aim of this clinical retrospective study was to evaluate the clinical quality, estimated survival rate, and failure analysis of different all-ceramic restorations in a long-term analysis of up to 20 years. Materials and Methods: Different all-ceramic restorations (crowns [n = 470], veneers [n = 318], onlays [n = 213], and inlays [n = 334]) were placed in 302 patients (120 men, 182 women) between 1987 and 2009 at 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. Number of restoration failures and reasons for failure were recorded. The study population included 106 (35.1%) individuals diagnosed with bruxism. The success rate was determined using Kaplan-Meier survival analysis. Results: The mean observation time was 102 ± 60 months. Ninety-five failures were recorded. The main reason for failure was fracture of the ceramic (33.68%). The estimated survival rate was 97.3% after 5 years, 93.5% at 10 years, and 78.5% at 20 years. Nonvital teeth showed a significantly higher risk of failure (P .0001). There was a 2.3-times greater risk of failure associated with existing parafunction (bruxism, P = .0045). Cementation using Variolink showed significantly fewer failures than Optec Cement (P = .0217) and Dual Cement (P = .0099). No significant differences were found for type of restoration and distribution in the mouth. Conclusion: All-ceramic restorations offer a predictable and successful restoration with an estimated survival probability of 93.5% over 10 years. Significantly increased failure rates are associated with bruxism, nonvital teeth, and specific cementation agents.

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.