Status of Tooth Loss and Denture Restoration in Chinese Adult Population: Findings from the 4th National Oral Health Survey.

OBJECTIVE: To investigate the status of tooth loss and denture restoration in Chinese adults, analyse the changing trend and provide fundamental data for oral health policy. METHODS: According to the protocol of the 4th National Oral Health Survey, a multistage stratified random cluster-sampling method was used to enrol adult subjects aged 35 to 44, 55 to 64 and 65 to 74 years in all 31 provinces, municipalities and autonomous regions of the mainland of China. The status of tooth loss and denture restoration was investigated. SPSS20.0 software was used for statistics analysis. RESULTS: Among the 13,464 subjects investigated, 13.8% had complete dentition, 84.4% had dentition defects, and 1.8% was edentulous. Urban subjects showed a significantly higher proportion of complete dentition than those in rural (P = 0.02), and males showed the statistically higher proportion of complete dentition than females (P = 0.01). The mean of remaining teeth was 26.1 ± 6.90, which in urban areas was significantly higher than in rural areas (P < 0.01). The means of remaining teeth were 29.6 ± 2.3, 26.3 ± 6.1, and 22.5 ± 8.7 in the 35 to 44, 55 to 64 and 65 to 74 age groups, respectively. The detection rate of fixed partial dentures (FPD) was statistically higher in urban than in rural areas and in males than that in females (P < 0.01). The detection rate of removable partial dentures (RPD) was statistically higher in urban areas than in rural locations (P < 0.01). However, the detection rates of irregular denture and unrepair of tooth loss were both significantly lower in urban than in rural areas (P < 0.01). The rate of restoration of tooth loss was 41.6% in Chinese adults. CONCLUSION: Although the tooth loss and denture restoration status recorded in the survey was improved compared with the results of 10 years ago, more efforts need to be made on strengthening oral health promotion, particularly for elderly people and those living in rural areas.

10-year randomized trial (RCT) of zirconia-ceramic and metal-ceramic fixed dental prostheses.

OBJECTIVES: To monitor zirconia-ceramic and metal-ceramic posterior FDPs with respect to survival and technical/biological complication rates. MATERIALS AND METHODS: Fifty-eight patients received 76 3- to 5-unit posterior FDPs. The sites were randomly assigned to 40 zirconia-based (ZC) and 36 metal-based (MC) FDPs. FDPs were examined at baseline (cementation), at 6 months, at 1 year and then yearly up to 10 years. Technical outcomes were assessed using modified United States Public Health Service (USPHS) criteria. Biologic outcomes included probing depth, plaque, bleeding on probing and tooth vitality. Statistical analysis was performed applying Kaplan-Meier (KM) estimation, log-rank, Mann-Whitney and Fisher exact test. RESULTS: During the 10-year follow-up thirteen patients (17 FDPs) dropped out and 6 FDPs in 6 patients (5 ZC,1 MC) were considered catastrophic failures for technical and/or biological reasons. Forty-four patients with 53 FDPs (29 ZC, 24 MC) were available for examination. The median observation period was 10.3 years (ZC) and 10.0 years (MC). The 10-year KM survival estimate of ZC FDPs was 91.3% (95%CI:69.5;97.8) and 100% of MC FDPs. Minor chipping of the veneering ceramic and occlusal wear were found to a similar extent at ZC and MC FDPs. ZC FDPs demonstrated a significantly higher rate of framework fracture, de-bonding, major fractures of the veneering ceramic and poor marginal adaption. Biological outcomes were similar in both groups and between abutment and control teeth. CONCLUSION: At 10 years, ZC and MC posterior FDPs resulted in similar outcomes for the majority of the outcome measures (p > 0.05).

A survey on the use of various gingival displacement techniques in fixed partial denture by the prosthodontists in vadodara city.

AIMS: To evaluate the use of various gingival displacement techniques prior to impression making in fixed partial dentures by the Prosthodontists in Vadodara. SETTINGS AND DESIGN: Questionnaire based survey among prosthodontists in Vadodara city. METHODS AND MATERIAL: All the prosthodontists practitioners and those prosthodontists in academic institutes in Vadodara City, Gujarat, were surveyed through a questionnaire regarding their usage of gingival displacement technique and their reasons and methods of using gingival displacement technique for fixed partial denture. The results were analysed through discriminant statistical analysis. RESULTS: Among all the Prosthodontists in Vadodara city, 62% prefer the use of gingival displacement technique for successful clinical practice while 38 % of them do not follow the procedure believing it does not make major difference in clinical practice. CONCLUSIONS: Those Prosthodontists who preferred the use of gingival displacement technique were able to detect many advantages of using it in their daily fixed partial denture practice and the percentage of prosthodontists not following gingival displacement technique blamed it as a time consuming affair and was not feasible on economic grounds for the class of patient they treated.

Zirconia-based versus metal-based single crowns veneered with overpressing ceramic for restoration of posterior endodontically treated teeth: 5-year results of a randomized controlled clinical study.

OBJECTIVES: The aim of this 5-year randomized controlled trial was to compare the longevity and clinical behavior of single posterior crowns made with pressable ceramic on zirconia and on metal frameworks, and if failures occur, to delineate the contributing factors. METHODS: 72 patients, who needed the covering of at least a molar and/or premolar, were included in the study. All teeth were endodontically treated, with absence of periapical lesion or active periodontitis. Ninety single crowns were made with zirconia or metal framework and covered with pressable veneering ceramics. Two independent examiners assessed the survival of restorations at 6 months, 1-4 and 5 years after restoration placement including periapical radiographs, intraoral photographs, and USPHS modified criteria. The statistical analyses were performed with the Kaplan-Meier method. RESULTS: One core fracture occurred in Zircad/Zirpress crowns and one metal ceramic crown was lost for root fracture. Chipping fracture of the veneering ceramic was detected in 2 metal-ceramic crowns and in 3 zirconia-based crowns. The Estimate Cumulative Survival (ECS) and the Estimate Cumulative Success (ECSs) with standard deviation (SE) were respectively 97,73±2,19 and 92,64±4,14 for zirconia-based crowns whereas 97,44±2,39 and 91,11±4,27 for porcelain fused to metal crowns. CONCLUSIONS: The present randomized controlled trial shows that the survival of zirconia-based and metal-based single crowns is similar over a follow-up period of 5 years. No significant differences in esthetic, functional and biological outcomes were demonstrated between the two groups. The main failure mode was the chipping fracture of the veneering ceramic in both materials. Study number on ClinicalTrial.gov NCT02758457. CLINICAL SIGNIFICANCE: According to the results of this clinical study, zirconia-based rehabilitations with overpressing veneering technique represent a valid alternative to metal-based for posterior single crown restorations.

Veneered zirconia inlay-retained fixed dental prostheses: 10-Year results from a prospective clinical study.

OBJECTIVE: The purpose of this study was to evaluate the 10-year clinical performance of zirconia-based inlay-retained fixed dental prostheses (IRFDP). METHODS: For replacement of a molar in 27 patients, 30 IRFDP were luted by use of different cements, Panavia F (Kuraray Europe GmbH) or Multilink Automix (Ivoclar Vivadent GmbH), with use of inlay/inlay, inlay/full-crown, or inlay/partial-crown retainers for anchorage. Frameworks were milled from yttria-stabilized zirconia (IPS e.maxZirCAD; Ivoclar Vivadent GmbH) and fully veneered with pressable ceramic (IPS e.max ZirPress; Ivoclar Vivadent GmbH). Before luting, the IRFDP were silica-coated (Rocatec; 3M Espe) and silanized (Monobond S; Ivoclar Vivadent GmbH). Complications (for example, chipping or delamination of the veneering ceramic, debonding, secondary caries, endodontic treatment, and abutment tooth fracture) and failure were reported, by use of standardized report forms, 2 weeks, 6 months, and 1, 2, and 10 years after cementation. Statistical analysis included Kaplan-Meier survival and success (complication-free survival) and Cox regression analysis (α=0.05 for all). RESULTS: During the 10-year observation period, the complications most often observed were chipping of the veneer and debonding. Twenty-five restorations failed and one participant dropped out. Cumulative 10-year survival and success were 12.1% and 0%, respectively. The design of the retainer, use of a dental dam, choice of cement, and location in the dental arch had no statistically significant effect on the occurrence of complications. CONCLUSIONS: Use of fully veneered zirconia-based IRFDP with this technique cannot be recommended. CLINICAL SIGNIFICANCE: A large incidence of complications and poor survival were observed for fully veneered zirconia-based IRFDP, revealing an urgent need for further design improvements for this type of restoration. This, again, emphasizes the need for testing of new restoration designs in clinical trials before implementation in general dental practice.

Simulation of multi-stage nonlinear bone remodeling induced by fixed partial dentures of different configurations: a comparative clinical and numerical study.

This paper aimed to develop a clinically validated bone remodeling algorithm by integrating bone's dynamic properties in a multi-stage fashion based on a four-year clinical follow-up of implant treatment. The configurational effects of fixed partial dentures (FPDs) were explored using a multi-stage remodeling rule. Three-dimensional real-time occlusal loads during maximum voluntary clenching were measured with a piezoelectric force transducer and were incorporated into a computerized tomography-based finite element mandibular model. Virtual X-ray images were generated based on simulation and statistically correlated with clinical data using linear regressions. The strain energy density-driven remodeling parameters were regulated over the time frame considered. A linear single-stage bone remodeling algorithm, with a single set of constant remodeling parameters, was found to poorly fit with clinical data through linear regression (low [Formula: see text] and R), whereas a time-dependent multi-stage algorithm better simulated the remodeling process (high [Formula: see text] and R) against the clinical results. The three-implant-supported and distally cantilevered FPDs presented noticeable and continuous bone apposition, mainly adjacent to the cervical and apical regions. The bridged and mesially cantilevered FPDs showed bone resorption or no visible bone formation in some areas. Time-dependent variation of bone remodeling parameters is recommended to better correlate remodeling simulation with clinical follow-up. The position of FPD pontics plays a critical role in mechanobiological functionality and bone remodeling. Caution should be exercised when selecting the cantilever FPD due to the risk of overloading bone resorption.

Analysis of Vertical Marginal Adaptation of Zirconia Fixed Dental Prosthesis Frameworks Fabricated by the CAD/CAM System: A Randomized, Double-Blind Study.

PURPOSE: The purpose of this study was to evaluate the marginal adaptation of fixed dental prosthesis frameworks fabricated by computer-aided design/computer-assisted manufacture (CAD/CAM) with three different systems of data acquisition. MATERIALS AND METHODS: A total of 50 specimens were fabricated as follows: using the conventional method (Ni-Cr) (n=10); iTero/industrial milling (Group 1, n=10); Cerec Bluecam/industrial milling (Group 2, n=10); 3S/industrial milling (Group 3, n=10); and Cerec BlueCam/Sirona milling (Group 4, n=10). The specimens were numbered and randomized, and the vertical marginal discrepancy was analyzed. RESULTS: Intraobserver analysis indicated no statistically significant difference (paired t test, P=.822) between periods before and after analysis. The conventional method (321 µm) showed greater discrepancy when compared with the CAD/CAM system (89 µm) (P<.001). The intraoral system showed a lower rate of marginal discrepancy when compared with the extraoral system (3S) (P<.001). The closed system presented a higher marginal discrepancy (114 µm) than the open intraoral system (iTero) at P<.001. In addition, the intraoral system when open showed statistically significant differences in mean marginal discrepancy values compared with the same system in closed condition (P>.05). CONCLUSION: The CAD/CAM systems showed less marginal discrepancy than the conventional method for the fabrication of the frameworks.

Tooth Loss and Prosthetic Treatment in Dependent and Functionally Impaired Individuals with Respect to Age and Gender.

PURPOSE: The aim of this study was to compare the prevalence of tooth loss and prosthetic treatments in dependent, functionally impaired individuals with the general population. MATERIALS AND METHODS: Data collected from 250 subjects from a register covering dependent and functionally impaired individuals in Sweden were compared with data from matched controls. The collected variables included number of teeth, tooth loss, and prosthetic treatments in the different jaw regions. RESULTS: The study group had a lower mean number of teeth and a higher proportion of complete tooth loss than the control group. Dentures were more common in the study group, and fixed prostheses, including dental implants, were more common in the control group. Gender-based differences related to tooth loss were also apparent. CONCLUSION: In spite of a well-organized recall system for dental care, differences still existed in tooth loss. The differences were more apparent in older individuals and appeared to be related to general health, functional impairments, and gender. Prosthetic treatment options were unevenly used and only one implant overdenture was found.

A multifactorial model of masticatory performance: the Suita study.

Previous studies have identified various factors related to masticatory performance. This study was aimed to investigate variations and impacts of factors related to masticatory performance among different occlusal support areas in general urban population in Japan. A total of 1875 Japanese subjects (mean age: 66·7 years) were included in the Suita study. Periodontal status was evaluated using the Community Periodontal Index (CPI). The number of functional teeth and occlusal support areas (OSA) were recorded, and the latter divided into three categories of perfect, decreased and lost OSA based on the Eichner Index. Masticatory performance was determined by means of test gummy jelly. For denture wearers, masticatory performance was measured with the dentures in place. The multiple linear regression analysis showed that, when controlling for other variables, masticatory performance was significantly associated with sex, number of functional teeth, maximum bite force and periodontal status in perfect OSA. Masticatory performance was significantly associated with number of functional teeth, maximum bite force and periodontal status in decreased OSA. In lost OSA, masticatory performance was significantly associated with maximum bite force. Maximum bite force was a factor significantly influencing masticatory performance that was common to all OSA groups. After controlling for possible confounding factors, the number of functional teeth and periodontal status were common factors in the perfect and decreased OSA groups, and only sex was significant in the perfect OSA group. These findings may help in providing dietary guidance to elderly people with tooth loss or periodontal disease.

An Up-to-15-Year Comparison of the Survival and Complication Burden of Three-Unit Tooth-Supported Fixed Dental Prostheses and Implant-Supported Single Crowns.

PURPOSE: To assess and compare the outcomes and economic complication burden of three-unit tooth-supported fixed dental prostheses (TFDPs) and implant-supported single crowns (ISCs) provided to a sequential cohort in a specialist prosthodontic practice over a 15-year period. MATERIALS AND METHODS: Sequential patients requiring replacement of a single missing tooth between 1996 and 2010 with a metal-ceramic three-unit TFDP (n = 145 patients, n = 174 prostheses) or ISC (n = 174 patients, n = 220 prostheses) were included. Prostheses subjectively judged at insertion to have an unfavorable 10-year prognosis (17 TFDPs, 0 ISCs) were removed from statistical analyses. The estimated cumulative survival (ECS) was calculated with the life table actuarial method and standard errors calculated with the Greenwood formula. Differences in outcomes between all prostheses and those replacing only anterior or only posterior teeth were assessed with the log rank test. Complication incidence, severity, and economic burden, measured in time/cost accounting units (TAUs), were tallied and compared descriptively. RESULTS: The 15-year ECS did not differ for 112 TFDPs (92.75% ± 3.28%) and 81 ISCs (95.95% ± 2.92%) replacing posterior teeth. However, the 15-year ECS was significantly greater for 139 ISCs (93.33% ± 6.44%) than for 45 TFDPs (82.82% ± 6.50%) replacing anterior teeth. The economic burden of nonterminal complications for both prostheses was low (mean = 0.3 and 0.2 TAUs per prosthesis for TFDPs and ISCs, respectively). This equated to 3 TAUs/100 years in clinical service and 4 TAUs/100 years in clinical service for the TFDPs and ISCs, respectively. CONCLUSION: The survival of three-unit TFDPs and ISCs over 15 years was not statistically different when replacing posterior teeth, but ISCs survived significantly better when replacing anterior teeth. The complication rates of the TFDPs and ISCs were similar, but the economic burden for the TFDPs was greater.

Three-Year Analysis of Fixed and Removable Telescopic Attachment-Retained Implant-Supported Dental Prostheses: Survival and Need for Maintenance.

PURPOSE: The purpose of this retrospective clinical study was to evaluate the clinical outcomes of fixed implant-supported dental prostheses (FISDPs) and removable ISDPs (RISDPs) retained by telescopic attachments, the factors influencing survival, and the type and number of maintenance treatments required during the observation period. MATERIALS AND METHODS: This retrospective clinical study is based on patients who were provided with ISDPs between 2004 and 2010. Patient sex, type of prosthesis, location, opposing dentition, and the effect of continuous follow-up on the probability of a favorable outcome, as well as the number of maintenance treatments, were analyzed. A statistical analysis was performed using the Kaplan-Meier method. RESULTS: A sample of 233 patients with 157 FISDPs and 76 RISDPs supported by a total of 567 implants was randomized and included in the analysis. The mean observation period was 15.9 ± 15.4 months (maximum, 66.0 months). During the observation period, 3.9% of prostheses (7/157 FISDPs and 2/76 RISDPs) ceased to function and 2.3% of implants (13 implants) were lost. The mean survival time was 59.7 ± 2.3 months, with a survival probability of 90.2% after 3 years. Prostheses in the mandible showed significantly higher survival rates than those in the maxilla. Maintenance treatments had to be performed at an earlier stage for patients with RISDPs than for patients with FISDPs. In patients with a conventional removable prosthesis in the opposing arch, the time until maintenance was needed was significantly shorter. CONCLUSION: Within the limitations of a retrospective study, it can be concluded that the FISDPs and RISDPs show equally good survival rates after 3 years in function. RISDPs showed a greater and earlier need for maintenance treatments during the first years in function.

A randomized controlled clinical trial of 3-unit posterior zirconia-ceramic fixed dental prostheses (FDP) with layered or pressed veneering ceramics: 3-year results.

OBJECTIVES: The aim of the present pilot study was to test whether or not posterior zirconia-ceramic fixed dental prostheses (FDPs) with pressed veneering ceramic exhibit less chipping than FDPs with layered veneering ceramics. METHODS: Forty patients (13 female, 27 male; mean age 54 years (range 26.1-80.7 years) in need of one maxillary or mandibular three-unit FDP in the second premolar or molar region were recruited and treated at two separate centers at the University of Zurich according to the same study protocol. The frameworks were made out of zirconia using a CAD/CAM system (Cerec Sirona, Bensheim, Germany). The patients were randomly assigned to either the test group (zirconia frameworks veneered with pressed ceramic; IPS e.max ZirPress, Ivoclar Vivadent AG, Schaan, Liechtenstein; n=20) or the control group (layered veneering ceramic; IPS e.max Ceram, Ivoclar Vivadent AG, Schaan, Liechtenstein; n=20). All FDPs were adhesively cemented and evaluated at baseline (i.e., cementation), at 6 months and at 1 and 3 years of clinical service. The survival of the reconstruction was recorded. The technical outcome was assessed using modified United States Public Health Services (USPHS) criteria. The biologic parameters analyzed at abutment teeth and analogous non-restored teeth included probing pocket depth (PPD), plaque control record (PCR), bleeding on probing (BOP), and tooth vitality (CO2). Data was descriptively analyzed and survival was calculated using Kaplan-Meier statistics. RESULTS: 36 patients (25 female, 11 male; mean age 52.3 years) with 18 test and 18 control FDPs were examined after a mean follow-up of 36 months (95% CI: 32.6-39.1 months). Comparison of groups was done by Crosstabulation showing even distribution of the respective restored teeth amidst the groups. Survival rate was 100% for both test and control FDPs. Chipping of the veneering ceramic tended to occur more frequently in test (n=8; 40%) than in control (n=4; 20%) FDPs, albeit not significantly (p=0.3). No further differences of the technical outcomes of test and control FDPs occurred.In both test and control group healthy conditions and no difference of the biologic parameters at the abutment and un-restored teeth was found. CONCLUSION: Zirconia FDPs with pressed and layered veneering ceramics exhibited similar outcomes at 3 years. A trend to more chipping of the pressed veneering ceramic, however, was observed. CLINICAL SIGNIFICANCE: Posterior restorations with zirconia frameworks are a viable treatment method. When restoring posterior teeth with all-ceramic restorations, care providers should be aware of the higher rate of chipping compared to the published data on conventional metal-ceramic restorations.

Axial Implants in Immediate Function for Partial Rehabilitation in the Maxilla and Mandible: A Retrospective Clinical Study Evaluating the Long-Term Outcome (Up to 10 Years).

BACKGROUND: There is a need of long-term studies evaluating the outcome of fixed partial rehabilitations (FPR) supported by implants in an immediate function protocol. The aim of this retrospective cohort study was to investigate the long-term outcome of FPR supported by implants placed in immediate function. METHODS: One hundred ninety-nine patients were consecutively included, between 1998 and 2010, with 481 implants supporting 213 FPR (maxilla: 87 and mandible: 126). Primary outcome measures were implant and FPR survival rates; secondary outcome measures were marginal bone levels at 5 and 10 years and incidence of mechanical and biological complications. RESULTS: The cumulative implant survival rate was 98.5% and 99.0% after 5 years and 92.7% and 96.7% after 10 years, using the patient and implant as unit of analysis, respectively. No prostheses were lost. Average (SD) marginal bone levels were 1.79 (0.93) and 1.89 mm (0.81 mm) at 5 and 10 years of follow-up. Mechanical complications occurred in 43 patients (21.6%), biological complications occurred in 12 patients (6%), and 16 implants (3.3%) up to the 10 years follow-up. CONCLUSIONS: FPR supported by immediate function implants in both jaws is a viable and safe treatment alternative.

Survival of teeth treated with cast post and cores: A retrospective analysis over an observation period of up to 19.5 years.

STATEMENT OF PROBLEM: Scientific data about the long-term survival of teeth treated with cast post and cores are scarce. Retrospective studies often use different target events for their analyses. A comparison is therefore complicated. For associated tooth-, jaw-, and patient-related factors little evidence exists as to their effect on survival. PURPOSE: The purpose of this study was to extend the knowledge on the survival of teeth treated with cast post and cores for observation periods of more than 10 years. A decrease or increase in survival times according to the presence or absence of associated parameters needs to be evaluated. MATERIAL AND METHODS: A retrospective evaluation was conducted of all cast post and cores inserted in 1 university clinic between January 1992 and June 2011. A Kaplan-Meier survival analysis was carried out by using extraction as the target event. The survival curves for different tooth types, the presence or absence of adjacent teeth, and the prosthetic restoration of the respective jaws were compared by using the log-rank test (α=.05). A Cox regression model was calculated for multivariate analyses. RESULTS: A total of 717 cast post and cores for 343 patients were recorded. The mean survival time was 13.5 years. A statistically significant decrease in survival times was found for canines (11.9 years) and premolars (13.4 years) versus molars (14.1 years), no adjacent teeth (10.6 years) versus at least 1 adjacent tooth (13.8 years), and the restoration with removable dental prostheses (12.5 years) versus fixed dental prostheses and single crowns (13.9 years). The largest reduction in survival time was found for teeth being used as an abutment for a double crown-retained removable partial dental prosthesis (telescopic denture) (9.8 years). Tooth type and adjacent tooth status remained as significant variables within the multivariate Cox regression model. CONCLUSIONS: Cast post and cores have an acceptable long-term survival time. Because different factors may influence survival, considering these factors in treatment planning may increase the long-term success of these restorations.

Treatment needs and skill mix workforce requirements for prosthodontic care: a comparison of estimates using normative and sociodental approaches.

BACKGROUND: The traditional measure for assessing dental treatment needs and workforce requirements based solely on normative need (NN) has major shortcomings. The sociodental approach (SDA) to assess needs overcomes some of the shortcomings as it combines normative and subjective needs assessments and also incorporates behavioural propensity (Sheiham and Tsakos 2007). The objective of this study was to estimate and compare prosthodontic treatment needs and workforce requirements, using the normative and the sociodental approaches for different skill mix models. METHODS: A cross-sectional study was conducted on 732 university employees aged 30-54 years. Normative prosthodontic need was assessed using the WHO (1997) method. The SDA includes NN and also considers oral impacts, measured through the OIDP index, and behavioural propensity. Estimates of prosthodontic need and dental workforce requirements using the two methods were compared using McNemar and Wilcoxon Signed Rank test respectively. The dental workforce required for prosthodontic treatment based on NN and SDA approaches were then compared using different workforce skill mix models. RESULTS: The proportion of subjects needing prosthodontic treatment was lower by more than 90% when the SDA was used compared to NN. The number of dentists required for prosthodontic treatment per 100,000 people were 98.8 using NN compared to 2.49 using SDA. Using a skill mix approach, the requirements for dentists per 100,000 people decreased slightly when more denture procedures were delegated to dental therapists. CONCLUSION: There were very much lower levels of prosthodontic treatment needs and workforce requirements when using the sociodental approach compared to normative methods.

Dental status and self-assessed chewing ability in 70- and 80-year-old subjects in Sweden.

The objective was to compare two cohorts of elderly people, 70 and 80 years old, with respect to dental status and self-assessed chewing ability. The hypotheses were as follows: (i) dental status is associated with self-assessed chewing ability; (ii) chewing ability is poorer among the 80- than the 70-year-old subjects. Identical questionnaires were in 2012 sent to all subjects born in 1942 and 1932, living in two Swedish counties. The response rate was 70.1% resulting in samples of 5697 70- and 2922 80-year-old subjects. Answers to questions on self-assessed chewing ability, dental status and some other factors have been analysed. Dental status varied but was in general good; 72% of the 70- and 60% of the 80-year-old subjects reported that they had all or only few missing teeth. Rate of edentulism was 3% and 7%, respectively. Removable partial dentures were reported by 6% and 10%, respectively, implant treatment by 13% in both cohorts. Self-assessed chewing ability was mostly good and correlated with the number of teeth (Spearman rho = 0.46). A majority of the edentulous subjects assessed their chewing ability as very or fairly good. Logistic regression showed that self-assessed chewing ability was significantly associated with a number of dental variables but also with general health. In conclusion, dental status was relatively good at both ages but somewhat poorer in the older cohort. Dental status, some other dental variables and being healthy were in both age groups significantly associated with self-assessed chewing ability.

Comparison of accuracy and reproducibility of casts made by digital and conventional methods.

STATEMENT OF PROBLEM: Little peer-reviewed information is available regarding the accuracy and reproducibility of digitally fabricated casts compared to conventional nondigital methods. PURPOSE: The purpose of this in vitro study was to compare the accuracy and reproducibility of a digital impression and cast fabrication with a conventional impression and cast fabrication. MATERIAL AND METHODS: Conventional impressions were made via a 1-step single viscosity technique with vinyl siloxanether material of a typodont master model, and conventional casts were cast from dental stone. Digital impressions were obtained with a digital scanner, and digital stereolithographic models were printed. The typodont and fabricated casts were digitized with a structured light scanner and saved in surface tessellation language (STL) format. All STL records were superimposed via a best-fit method. The digital impression and cast fabrication method was compared with the conventional impression and cast fabrication method for discrepancy, accuracy, and reproducibility. The Levene test was used to determine equality of variances, and a 1-way ANOVA was conducted to assess the overall statistical significance of differences among the groups (n=5, α=.05). RESULTS: No significant statistical difference was found between the digital cast and conventional casts in the internal area or finish line area (P>.05). In addition, there was no statistically significant difference between these 2 techniques for a fixed dental prosthesis or single crown (P>.05). However, statistically significant differences were observed for overall areas of the casts in terms of accuracy (P<.01) and reproducibility (P<.001). Digital impression and cast fabrication were less accurate and reproducible than conventional impression and cast fabrication methods. CONCLUSIONS: No statistically significant difference was found between the digital cast and conventional cast groups in the internal and finish line areas. However, in terms of the reproducibility and accuracy of the entire cast area, the conventional cast was significantly better than the digital cast.

Is prosthodontic treatment age-dependent in patients 60 years and older in Public Dental Services?

Prosthodontic treatment is a common procedure for the elderly as tooth loss is a reality in old age. Dentists take care of increasingly older patients with physiological age manifesting as cognitive impairment, frailty or multiple chronic diseases or who have side effects of medicines. We evaluated how patients' age affects prosthodontic treatment choice and whether we could identify the age when a change in practice occurs. In addition, we determined how common the treatment method of fixed prostheses is among patients aged 60 years or over in Public Dental Services (PDS) and how common rehabilitation of dentition with new dentures is compared with repair of existing dentures. Our data cover all patients aged 60 years and older (n = 130,060) treated in Helsinki PDS in 2007-2012. Data were aggregated into seven groups: 60-64, 65-69, 70-74, 75-79, 80-84, 85-89, and 90 years and over. During the 6-year period, the mean annual number of the population was about 114,000 and the mean annual number of patients treated with prosthodontics 1700. Prosthodontic treatment choices (repair, removable prosthodontics, fixed prostheses, fibre-reinforced composite fixed prostheses) vary by age; the older the patient, the rarer fixed or fibre-reinforced composite fixed prostheses and removable prostheses and the more frequent repairs (P < 0.001). Denture repair was virtually the only treatment that patients over 90 years received. Based on our results, the age at which prosthodontic treatment practices in PDS change is around 70 years. Beyond this age, fixed prosthodontic treatment modalities are very rare and repairs are more common.

Partial Edentulism based on Kennedy's classifcation: an epidemiological study.

BACKGROUND: The aim of this study was to determine the incidence of different Kennedy's classes of partial edentulism during 18 months period. MATERIALS AND METHODS: Patients were clinically examined for various Kennedy's classes of partial edentulism in the outpatient department (OPD), prosthodontics, GPRDCH, Kurnool (Andhra Pradesh). RESULTS: Of the total 1,420 OPD patients, Kennedy's class III was the most frequent classification encountered (62%) and followed by Kennedy's class I (18%), class II (11%), and class IV (9%) in decreasing order. CONCLUSION: The patients with various Kennedy's classes of partial edentulism can be offered various treatment modalities like removable cast partial dentures, fixed partial dentures, over dentures and implant supported dentures. This study can be crucial for screening the population for incidence of tooth loss as a factor of gender and age. Clinical significance: Tooth loss appears to have an important role in the loss of esthetics and mastication. Study of incidence of various classes of partial edentulism provides clinically useful information for dental training and continuing education.

Making sense of complication reporting associated with fixed dental prostheses.

The current reporting of complications associated with FDPs is inadequate and misleading. Complications,which incur significant monetary costs, will particularly impact the perceived value (worth or importance)that patients derive from their prostheses.Effective documentation of complications should include type (biologic and technical), incidence, and severity. The fiscal burden of treatment should be quantified. Comparisons of different restorative materials,techniques, and procedures should be meaningful.Data collated prospectively or retrospectively and pooled over time should allow for comparisons within and between different practice settings. The proposed classification, based on the fiscal consequences of complications, achieves these objectives.Effective documentation of complications in conjunction with actual or projected survival data and personal clinical experience will enable clinicians to provide realistic information of the expected clinical service of dental prostheses.