The International Journal of Prosthodontics, 04/2012

Purpose: Resonance frequency analysis (RFA) is used to measure oral implant stability. There is controversy with regard to its accuracy in predicting both implant stability and osseointegration. This systematic review and meta-analysis determined the prognostic accuracy of RFA in predicting implant failure following immediate loading protocols. Materials and Methods: MEDLINE, EMBASE, the Cochrane Oral Health Group's Trials Register, the United Kingdom National Research Register, the Australian New Zealand Clinical Trials Registry, the Database of Abstracts of Reviews of Effectiveness, and the Conference Proceedings Citations Index were searched to select studies that used RFA in assessing implant stability prior to immediate loading. The sensitivity, specificity, and accuracy of RFA in the selected studies were evaluated using a random effects model. The summary receiver operating characteristic was constructed to summarize the overall test performance. Results: Fifteen studies with 2,236 immediately loaded implants were identified. The sensitivity of RFA in predicting failure of immediately loaded implants was 0.38 (95% confidence interval [CI]: 0.22 to 0.56), the specificity was 0.73 (95% CI: 0.71 to 0.75), and the diagnostic odds ratio was 2.10 (95% CI: 0.79 to 5.57). The area under the curve was 0.54, suggesting a poor predictive and discriminative ability. Conclusion: RFA measurement at the time of implant placement is not sufficiently accurate to determine implant stability and osseointegration during immediate loading protocols.

Purpose: This study compared the dietary intake of edentulous subjects dissatisfied with their existing mandibular complete dentures following two different prosthodontic management interventions. Materials and Methods: A convenience sample of 60 subjects was randomly allocated into two equal treatment modalities: relined conventional denture (RCD) or converted implant-retained overdenture (IOD). Two-year data incorporating demographics and food avoidance were recorded using a self-administered questionnaire at baseline and regular follow-up intervals. Twenty-four-hour dietary intake assessments were obtained by telephone interviews at three spaced intervals. Dietary analyses were based on nutrient values from the Norwegian Food Composition Table. Results: Twenty-seven patients in the IOD group and 26 in the RCD group completed the protocol. There were no statistical differences regarding dietary intake and energy distribution. Intake of protein and fat, especially saturated fat, were above Nordic recommendations, and carbohydrate intake was below. Vitamin D intake was at the recommended level, but that of vitamin C, folate, and fiber were lower than recommended. The IOD group reported significantly less avoidance of certain food items at 3 and 24 months (P .001), better chewing ability (P .001), and greater willingness to eat more of some food items (P .001). Conclusion: There were no significant differences regarding food choices and nutrient intake between the IOD and RCD groups. However, the IOD group reported significantly better chewing ability, less food avoidance, and greater willingness to eat more of certain food items.

Purpose: The aim of this research was to compare the differences between patients with myofascial pain and disc displacement and asymptomatic individuals based on aspects of psychologic status and sleep quality. Materials and Methods: One hundred thirty patients (81 women, 49 men; mean ages: 30.0 and 31.0 years, respectively) with temporomandibular disorder were selected, and 64 control subjects (32 women, 32 men; mean ages: 27.2 and 27.5 years, respectively) were included in the investigation over a period of 1 year. Clinical diagnosis of 65 patients with myofascial pain and 65 patients with disc displacement with or without limitation and joint pain was determined according to the Research Diagnostic Criteria for Temporomandibular Disorders. The Pittsburgh Sleep Quality Index (PSQI) was used to evaluate sleep quality. Psychologic status was assessed using Symptom Checklist-90-Revised (SCL-90-R). Chi-square, Kolmogorov-Smirnov, one-way analysis of variance, and Tukey Honestly Significant Difference post hoc multiple comparison or Tamhane T2 tests were used for statistical analysis. Results: There was a significant difference between patients with myofascial pain and disc displacement regarding somatization and paranoid ideation. No statistically significant difference was found between patients with disc displacements and controls in all dimensions of the SCL-90-R. Total score for the PSQI was statistically significantly different between patients with myofascial pain and controls; no significant differences were found between patients with disc displacement and those with myofascial pain or controls regarding the PSQI. Conclusion: To manage patients with myofascial pain, psychologic assessments including sleep quality should be considered.

This study aimed to determine how impression technique and pouring time affect casts obtained using polyvinyl siloxane (PVS) and polyether (PE) impressions. A total of 480 impressions were taken using three techniques: single-step (SS), two-step (TS), and two-step with a spacer (TSS). Impressions were poured after 1 and 24 hours and 7 and 14 days. Significant differences (P .01) were found between the TS technique and the SS and TSS methods as well as between PE and PVS (P .01) in terms of the effects of pouring time. SS and TSS yielded similar dimensional results, while greater dimensional change was induced with TS. PE impressions had to be poured no later than 7 days after preparation to ensure dimensional stability.

Correct measurement of crown length is important for calculating the crown-implant ratio. The aim of this study was to compare the length of implant-supported crowns measured on digitized casts and intraoral radiographs. Crown lengths were studied in 50 patients with 86 implant-supported crowns in the posterior region. The mean length of implant-supported crowns was 9.83 ± 1.72 mm on three-dimensional models and 10.99 ± 1.91 mm on radiographs, which is a statistically significant difference (P .001). It can be concluded that a new gold standard for crown measurement should be defined.

Purpose: The aims of this study were to reexamine patients who had received fixed dental prostheses (FDPs) more than 10 years prior, list the frequencies of observed technical and biologic failures and complications, and calculate the estimated failure and complication rates at 10 and 15 years. Materials and Methods: Fifty-six of 195 patients who were treated by undergraduate students during their state board examinations in fixed prosthodontics between 1990 and 1999 at the School of Dental Medicine, University of Bern, Bern, Switzerland, were recalled successfully. Results: At reexamination, it was determined that 56 patients with a mean age of 62 years (range: 41 to 85 years) had received 95 metal-ceramic FDPs supported by 202 abutment teeth. Prostheses had been in function for 7 to 19 years (mean: 14 years). The FDPs demonstrated a high estimated survival rate of 90.4% after 10 years and 80.5% after 15 years, although 17 of the 202 abutment teeth had been lost. The probability to remain free from any complication/failure was 79.7% at 10 years and 34.6% at 15 years. The risk of FDPs being affected by a biologic complication or failure after 10 years was 14.9%; the risk was 5.34% for a technical complication or failure. After 15 years, the risks of a biologic or technical complication or failure were 45.7% and 19.7%, respectively. Conclusions: The survival rates of FDPs decreased gradually with time. Freedom from complications and failures was drastically decreased for FDPs that had been in function for longer than 10 years.

Purpose: The aim of this study was to investigate the association of masticatory ability and dental status with intake of fruits and vegetables after adjusting for other factors in independently living elderly Japanese subjects. Materials and Methods: The study population consisted of 1,535 community-dwelling, independent elderly subjects over the age of 60 years. Self-assessed general health, financial status, dental status, self-assessed masticatory ability by food acceptance, and frequency of food intake were evaluated from responses to a questionnaire. Multiple logistic regression analysis for shortage of food intake was carried out. Results: Of the participants, 29% had natural dentitions in both the maxilla and mandible and 15% were edentulous in at least one arch and wearing a complete denture. Percentages of participants with nutrient shortages of meat, fish and seafood, green and yellow vegetables, other vegetables, and fruits were 44%, 17%, 30%, 33%, and 12%, respectively. Multiple logistic regression analysis showed that men and subjects with a poor financial status had significant associations with shortages of dietary intake. In addition, shortages of meat, green and yellow vegetables, other vegetables, and fruit were significantly related to poor masticatory ability but not to dental status. Masticatory ability was significantly associated with shortages of green and yellow vegetables. Conclusion: Multivariate analyses showed that after adjusting for age, sex, and financial status, self-assessed masticatory ability rather than dental status by itself was significantly associated with shortages in vegetable and fruit intake in independently living elderly Japanese subjects.

The purpose of this study was to evaluate a new denture-cleaning device using hydroxyl radicals generated from photolysis of hydrogen peroxide (H2O2). Electron spin resonance analysis demonstrated that the yield of hydroxyl radicals increased with the concentration of H2O2 and light irradiation time. Staphylococcus aureus, Pseudomonas aeruginosa, and methicillin-resistant S aureus were killed within 10 minutes with a > 5-log reduction when treated with photolysis of 500 mM H2O2; Candida albicans was killed within 30 minutes with a > 4-log reduction with photolysis of 1,000 mM H2O2. The clinical test demonstrated that the device could effectively reduce microorganisms in denture plaque by approximately 7-log order within 20 minutes.

Purpose: The aim of this article is to systematically review the literature on prosthodontic maintenance requirements of maxillary implant overdentures with different prosthodontic designs. Materials and Methods: A standard approach of searching MEDLINE, PubMed, and Google Scholar databases as well as early online journal articles was followed. Hand-searching identified other relevant articles from the reference lists of the articles found. Selection criteria were details of prosthodontic maintenance related to different prosthodontic designs of maxillary implant overdentures, regardless of the dentition of the opposing arch or prosthesis. Results: From a total of 58 relevant studies identified, only 18 met the criteria. Several categories were used to document the prosthodontic maintenance of maxillary implant overdentures, usually with four or more splinted or unsplinted implants using different attachment systems. Aspects of patrix and matrix maintenance were primarily reported, although soft tissue complications were described frequently. Subjective information on relines and the rationale for minimizing overdenture fractures was found. Conclusions: Prosthodontic maintenance requirements of maxillary overdentures are a direct consequence of the attachment system, together with differing numbers and distributions of implants. The reviewed literature does not provide a clear controlled indication of prosthodontic maintenance requirements of maxillary overdentures for different prosthodontic designs and attachment systems. Future standardization of maxillary implant overdenture design is recommended, and universally accepted criteria for reporting maxillary implant overdenture maintenance should be implemented to establish accurate comparative data analysis.

The aim of this study was to investigate the prosthodontic maintenance requirements of patients rehabilitated with maxillary and mandibular implant-retained overdentures using the Locator Attachment System by retrospectively reviewing case records. Fifty patients made 112 unplanned return visits over a 3-year period. The most common reasons for returning were denture adjustments (n = 45), inadequate retention (n = 39), and loosening of the implant abutments (n = 14). Implant-retained overdentures using the Locator Attachment System have comparable prosthodontic maintenance requirements to other attachment systems. Problems associated with these prostheses are usually simple to resolve chairside.

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 Methods: 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.

Purpose: The aim of this prospective study was to evaluate the clinical performance of zirconia-based posterior four-unit fixed dental prostheses (FDPs) after 4 years of clinical observation. Materials and Methods: Between 2006 and 2010, 10 patients (5 women, 5 men; mean age: 52.8 years) received 17 posterior four-unit FDPs. Two calibrated examiners evaluated the FDPs independently 1 week (baseline), 6 months, and 1, 2, 3, and 4 years after placement using California Dental Association (CDA) criteria. Periodontal status was assessed on both the abutment and contralateral control teeth using Plaque Index, Gingival Index, probing attachment level, and Margin Index parameters. Statistical analysis was performed using descriptive statistics and the Wilcoxon signed-rank test. Results: Three restorations were lost because of fractures at their distal connectors after a mean clinical service of 25.3 months, and one abutment tooth was extracted because of vertical root fracture 23 months after cementation. Three FDPs presented chipping of a moderate size 1 week before framework fracture, and minor chipping was observed in 2 other FDPs 1 week and 36 months after cementation. After 4 years of clinical service, the cumulative survival rate of the posterior four-unit FDPs was 76.5%. No caries lesions were detected on the abutment teeth. The remaining restorations were judged to be satisfactory according to the CDA criteria. Periodontal parameters did not show significant differences between test and control teeth, but Gingival Index scores demonstrated a slight increase in inflammation in the distal abutments after 4 years (P = .016). Conclusions: The use of zirconia-based posterior four-unit FDPs should be restricted for patients with high esthetic demands, except in patients where at least 4 mm of height is available for connector thickness.

The aim of this study was to evaluate whether the VITA Classical shade guide arranged according to lightness allows clinicians to more often obtain a shade match than with an arrangement based on hue groups. A panel of 50 students determined the shade of the maxillary right central incisors of three patients with two differently arranged and blinded shade guides under standardized conditions. The L*a*b* values of the tabs were compared with those of the teeth spectrophotometrically. There were no statistically significant differences between the two arrangements. Using the arrangement according to lightness did not result in improved correct shade selection.