The International Journal of Prosthodontics, 01/2011

Purpose: The aim of this study was to explore variables that might influence self-reported oral health and denture satisfaction in partially and completely edentulous patients. Materials and Methods: The study sample was recruited from 294 patients treated with complete dentures at the Department of Prosthodontics, Faculty of Dentistry, University of Bergen, Norway, between 1997 and 2005. The 172 respondents completed a self-administered questionnaire regarding demographics, denture status, appetite, avoiding food items, satisfaction with dentures, various aspects of wearing dentures, and the Oral Health Impact Profile (OHIP-20). Results: The mean age of patients was 67 years; 52% were men. Sixty-seven percent of patients had complete maxillary and mandibular dentures, while 33% had a complete maxillary denture and a dentate mandible. There were no significant group differences regarding age, sex, general health, appetite, avoiding food items, chewing, speech, maxillary denture esthetics, or the OHIP-20. However, striking group differences were found in the number and nature of significant variables associated with reported oral health and denture satisfaction at all levels of analyses. Thus, oral health in the completely edentulous was associated with the OHIP-20, avoiding food items, and satisfaction with dentures, while in the partially edentulous, it was associated with maxillary denture retention and age. Similarly, satisfaction with dentures in the completely edentulous was associated with the OHIP-20, global oral health, and some clinical variables, while in the partially edentulous, it was associated with the OHIP-20 and some clinical variables. Predictors for oral health in the completely edentulous were the OHIP-20, speech, and avoiding certain food items; in the partially edentulous, they were denture retention and age. Predictors for denture satisfaction in the completely edentulous were the OHIP-20 and maxillary denture esthetics; in the partially edentulous, only maxillary denture comfort served as a predictor. Also, the completely edentulous reported better oral health and satisfaction with their dentures than the partially edentulous. Conclusion: The results of this study suggest that the completely and partially edentulous differ in variables associated with, and predictive for, both self-reported oral health and denture satisfaction.

Purpose: During extensive prosthodontic treatment, the use of an accurately adjusted articulator is recommended to simulate mandibular movements. This clinical study was undertaken to assess any possible effect of the underlying skeletal pattern on programming articulator settings. Materials and Methods: Subjects (n = 73, mean age: 22.8 ± 6.8 years) were recruited from a dental school and two regional specialist orthodontic units. Subjects were allocated into groups based on their underlying sagittal (I, II, or III) and vertical (reduced, average, or increased) skeletal patterns by three orthodontists and three prosthodontists who examined their profile photographs. Electronic pantographic recordings were made of each subject using the Cadiax Compact system to record the sagittal condylar inclination (SCI), progressive mandibular lateral translation (PMLT), and immediate mandibular lateral translation (IMLT). Results: Agreement between assessors for sagittal skeletal pattern classification was excellent (97% for total or good agreement); agreement for vertical skeletal pattern was high, but at a lower level than that for sagittal relationships (70% for total or good agreement). SCI settings for sagittal II subjects were significantly higher than those for sagittal I (P .05) and sagittal III (P .001) subjects. Differences were statistically significant, with mean SCI differences of 4 and 7 degrees, respectively. No statistical difference could be observed between SCI values in the sagittal I and III groups. Subjects with an average vertical skeletal pattern had SCI values lower than those with a reduced vertical skeletal pattern (P = .058) and an increased vertical skeletal pattern (P .01, statistically significant). No patterns could be determined for PMLT or IMLT between the study groups. Conclusion: During prosthodontic treatment of patients with a noticeable skeletal discrepancy, appropriate consideration should be given to customizing SCI values.

The rehabilitation of eroded teeth in patients suffering from bulimia nervosa generally includes ceramics. This study compared the roughness of three ceramics before and after exposure to simulated vomit solution (SVS) with a pH of 3.8. Surface roughness parameters Ra, RMS, and AH were calculated using atomic force microscopy before and after exposure to SVS (novel peristaltic pump for 24 hours at 37°C) and were analyzed statistically. Apart from the initial high AH values of the glass-ceramic, none of the parameters evaluated were statistically significantly different after acid exposure. Under the limitations of this in vitro study, the investigated ceramics seem suitable for use in bulimia nervosa patients.

Purpose: The aim of this study was to explore the dental functional status of a Southern Vietnamese adult population using a new quantitative- and qualitative-based classification system. Materials and Methods: The sample consisted of 2,809 dentate subjects aged >= 20 years from urban and rural areas of Southern Vietnam. Dentitions were classified by a dichotomized five-level step-by-step branching hierarchy reflecting functionality. Cut-offs were as follows: level I (dentition level) = 1 tooth present in each arch, level II (arch level) = 10 teeth in each arch, level III (anterior region) = all 12 anterior teeth present, level IV (premolar region) = >= 3 premolar posterior opposing pairs (POPs) present, and level V (molar region) = 1 molar POP bilaterally. Results: Of the 2,809 subjects, 44% met all criteria for a functional dentition and 16% met none. Of subjects meeting level II, 81% had a complete anterior region, 74% had a sufficient premolar region, and 66% had a sufficient molar region. For subjects not meeting level II, these figures were 9%, 15%, and 8%, respectively. For patients meeting level II who were between 20 and 35 years of age, a mean 29.2 ± 2.4 teeth and 7.9 ± 2.1 POPs were present; subjects 65 years of age and older had a mean 25.6 ± 3.2 teeth and 5.9 ± 2.1 POPs. For patients not meeting level II, these numbers were 18.6 ± 2.9 teeth and 3.1 ± 1.8 POPs and 12.8 ± 5.4 teeth and 0.9 ± 1.4 POPs for 20- to 35-year-olds and those 65 years of age and older, respectively. Intraclass correlation coefficients for number of teeth and POPs showed fair to good group homogeneities. Conclusions: The World Health Organization goal of retaining at least 20 teeth throughout life is not achieved in Southern Vietnam; above the age of 44, less than 75% of subjects presented with 20 or more teeth. The presented classification system is a useful framework for mapping the functionality of dentitions by applying additional criteria for dental regions.

The purpose of this study was to determine the accuracy of mechanical torque devices in delivering target torque values in dental offices in Salvador, Brazil. A team of researchers visited 16 dental offices, and the clinicians applied torque values (20 and 32 Ncm) to electronic torque controllers. Five repetitions were completed at each torque value and data were collected. When 20 Ncm of torque was used, 62.5% of measured values were accurate (within 10% of the target value). For 32 Ncm, however, only 37.5% of these values were achieved. Several of the tested mechanical torque devices were inaccurate.

The aim of this study was to evaluate the performance of IPS Empress ceramic onlays luted with two dual-cured adhesive resin cements for endodontically treated teeth. Twenty molar teeth were restored with all-ceramic restorations luted randomly with Maxcem or Clearfil Esthetic Cement & DC Bond Kit luting systems (n = 10 each) in 20 patients. The restorations were assessed using modified US Public Health Service criteria at baseline, 6 months, and 1, 2, and 3 years. A statistically significant deterioration was found for the criteria marginal integrity, anatomical form, and surface roughness. For luting of ceramic onlays, no difference between the two luting systems was detected.

The aim of this study was to establish a method for in vivo examination of the load-bearing ratio between mucosa and abutments beneath an overdenture. Two patients wearing a four tooth-supported or a four implant-supported overdenture were enrolled in this study. Recordings were performed with the metal framework only or with a metal framework and a denture base. The force value with the framework only was designated as 100%, and the tissue-supporting ratio (TSR) with the denture base was calculated. The TSR was approximately 30% to 40% in both subjects, regardless of the load. These data suggest that measurement of a TSR beneath an overdenture is feasible.

This study evaluated the clinical outcome of posterior single-unit metal-ceramic crowns fabricated using computer-aided design/computer-assisted manufacture laser-sintering technology. Sixty restorations were placed in 39 patients and cemented with glass-ionomer cement. Follow-ups were performed annually. During a mean observation period of 47 months, one restoration was regarded a dropout, one crown failed (biologic failure), and one debonded. One abutment tooth had to be treated endodontically, and three teeth were treated because of caries. No further technical complications, eg, veneering ceramic chipping, occurred during the observation period. The results suggest that the clinical outcome of posterior single-unit metal-ceramic crowns fabricated using laser-sintering technology is promising.

Purpose: The aim of this study was to determine how tray rigidity and impression technique affect the accuracy of polyvinyl siloxane impressions. Materials and Methods: Disposable plastic trays and metallic Rim-Lock trays were used in combination with a heavy/light body technique or with two different putty-wash techniques. For each technique-tray combination, 10 impressions were made of a master cast with two steel abutments representing the mandibular right first premolar and second molar, between which a steel rod was placed at the ridge level. Each steel abutment had five marks, while the steel rod in between the two abutments had only one mark, which served as a reference point. With a universal measuring microscope, the x-, y-, and z-coordinates were recorded for each mark on the master cast and impressions. The distances between the different marks and the reference point on the impressions were calculated and compared with those of the master cast. Results: All techniques used with the plastic trays had distances that were significantly different from the master cast (P .05), while for the metal trays, it was only the heavy/light body technique that resulted in distances that were significantly different from the master cast (P .05). Conclusion: Plastic trays produced less accurate impressions than metal trays. When metal trays were used, putty-based impressions were dimensionally better than heavy/light body impressions.

The aim of this study was to quantify the frequency of positive radiographic findings in edentulous arches. Panoramic radiographs from 271 patients who were edentulous in one or both arches were evaluated for the presence of retained root fragments, impacted teeth, foreign bodies, radiolucencies, radiopacities, mental foramina at or near the crest of the residual alveolar ridge, and maxillary sinus proximity to the crest of the residual alveolar ridge. One or more of these radiographic observations were found in 51.7% of the examined films. The most frequent finding (30.6%) was close approximation of the maxillary sinus to the crest of the ridge. These results underscore the importance of panoramic examination of edentulous patients in detecting potential problems before complete denture treatment. However, prescribing such an examination in patients seeking replacement dentures requires a thorough patient history and clinical examination.

Purpose: The aims of this in vitro study were to analyze temperature changes along the surface of a dental implant and to establish the abutment temperature that could cause the critical 47°C/1 min threshold at the implant level. Materials and Methods: Eight thermocouples were attached at 1-mm intervals to an abutment/implant configuration. The model consisted of two compartments in a thermostatically controlled environment. The upper compartment represented the oral cavity with the abutment, which was exposed to 20 mL of hot water. The temperature at each thermocouple was logged over a period of 10 minutes. The Spearman rank correlation test and logistic regression model were used for the statistical analysis of the time/temperature databases and the estimation of the "effective dose 50" (ED50) for the abutment (95% confidence interval). Results: For 53 test series, the abutment temperature ranged from 52.80°C to 71.72°C. There was a positive correlation between the maximum temperature at the implant level and the temperature of the abutment. The 47°C/1 min threshold was reached 31 times at the most cervical implant level and decreased in frequency farther away from the heat source (14, 6, 3, 1, and 1 times, respectively). The ED50 was estimated at 62.3°C. This means that for an abutment temperature of 62.3°C, there was a 50% chance that 47°C would be reached at the implant level for 1 minute. Conclusion: This in vitro study supports the hypothesis that abutment temperature is transmitted to an implant. Although results of in vitro studies should be interpreted with caution, clinicians should be aware of temperature changes along implants and the potential risks associated with them.

Purpose: The aim of this study was to evaluate the existence of different esthetic smile criteria as determined on the smiles of celebrities, which were considered by lay people to be beautiful. Materials and Methods: An Internet search for "best smile" and "female celebrities" in the years 2007 and 2008 identified 50 celebrities who were voted to have beautiful smiles. Another search was made for images of these celebrities that showed the entire face with an open smile. The images were analyzed using Digimizer image analysis software for different esthetic smile criteria. Results: Eighty percent of the sample was classified as having an average upper lip position, 62% showed upward upper lip curvature, and 78% had a parallel smile line. Forty-two percent of the images showed the maxillary anterior teeth not touching the lower lip, while 34% were touching, and 24% slightly covered it. Sixty percent displayed up to the second premolar, and 32% displayed up to the first molar when smiling. Midline deviation was detected in 36% of the sample. Diastema and golden proportion were not seen in any of the subjects. Conclusion: Female celebrities voted to have the best smile by lay people showed most of the esthetic smile criteria with slight variations, except for the golden proportion. The opinions and perceptions of lay people about beauty should be studied and evaluated.

Purpose: The aim of this study was to evaluate the clinical outcomes from a predoctoral implant clinic over 3 years. Materials and Methods: All patients who received implant-retained mandibular overdentures (IODs) or a single-tooth implant (STI) restoration in the Predoctoral Implant Program at the University of Illinois-Chicago College of Dentistry between 2006 and 2009 were included in this study. A two-stage surgical placement and healing protocol was followed by oral surgery, periodontic, and prosthodontic specialty clinics. The following potential prognostic information was collected: patient age and sex; implant diameter, length, and sites; and complications related to the treatment. Life-table and Kaplan-Meier survival analyses were performed for both IOD and STI patient groups. Results: A total of 371 implants were placed in 243 patients. There were 164 implants placed in 82 patients in the IOD group and 207 implants placed in 161 patients in the STI group. Two implants failed in the IOD group and 2 implants failed in the STI group. The cumulative survival rates for the implants in both the IOD and STI groups were 99%. Kaplan-Meier survival analysis showed no significant differences between the two groups. The most common complication observed in the IOD group was damage to the attachment inserts, and for the STI group, it was repair or remaking of the definitive prosthesis. Conclusion: As demonstrated by the 3-year clinical outcomes, a predoctoral implant program can provide predictable patient-centered therapy with few complications. Patient therapy, guided by thoughtful diagnosis and driven by restorative outcome, can lead to favorable results.

Purpose: The aim of this randomized controlled clinical trial was to compare the outcome of feldspathic porcelain (group 1) and glass-infiltrated alumina all-ceramic (group 2) crowns. Materials and Methods: Patients were recruited based on inclusion/exclusion criteria, and 33 eligible subjects were assigned randomly to one of the two treatment groups. One hundred one crowns were placed predominantly in the anterior portion of the mouth and were cemented using resin cement. A baseline California Dental Association quality evaluation was completed, and Plaque and Gingival Index scores were recorded. Prosthetic and soft tissue scores were recorded for up to 3 years. Results: Five restorations experienced mechanical failure. Kaplan-Meier analysis showed that the 3-year survival probabilities for group 1 (0.94) and group 2 (0.95) restorations were comparable (P = .484). Plaque and Gingival Index scores for both groups were similar at the 3-year recall (P > .999). Marginal integrity, anatomical form, and color and surface scores were also similar for both groups (P > .05). Conclusion: Feldspathic and glass-infiltrated alumina all-ceramic crowns placed predominantly in the anterior portion have comparable biologic and prosthetic outcomes, as well as survival probabilities.