Survival of cast-metal, resin-bonded fixed partial dental prostheses after nearly 20-year follow-up: A retrospective study.

STATEMENT OF PROBLEM: Cast-metal resin-bonded fixed partial dental prostheses (RBFPDPs) are a conservative approach to replacing missing teeth. Despite their recognized advantages, the use of cast-metal RBFPDPs as a definitive option remains somewhat controversial because of the lack of long-term studies on their success. PURPOSE: The purpose of this retrospective study was to evaluate the long-term survival rate of cast-metal RBFPDPs and investigate the influence of covariates such as sex, type of prosthesis, location, number of pontics, abutments, and type of luting cement on the survival of bonded prostheses. MATERIAL AND METHODS: This study evaluated 209 cast-metal RBFPDPs cemented in 181 patients (mean 41.06 ±11.90 years of age) treated in the principal author's private practice between July 1993 and May 2012. Data sheets were completed at the patients' recall examination at regular intervals or if seen for complications. Kaplan-Meier analysis was used to evaluate the survival rate of the prostheses before debonding. The Cox model and Wald test were used to analyze the prognostic factors (α=.05). RESULTS: A total of 198 prostheses were studied. Eleven cast-metal RBFPDPs were lost to follow-up. This study evaluated the effect of different variables on the survival rate of both conventional RBFPDPs (wing-wing) and combination resin-bonded FPDPs (wing-crown) types. Survival rate was divided into "with repair" and "without repair" groups. The mean survival time was 102.24 months for the group with no repair and 119.76 months for the group with repair. The survival rate after 5, 10, and 15 years was 86%, 42%, and 15% with repair, whereas 69%, 32%, and 14% of the prostheses survived without repair. CONCLUSIONS: In appropriate clinical conditions and selected patients, cast-metal RBFPDPs were a viable treatment option with an acceptable survival rate.

Improvements in dental care using a new mobile app with cloud services.

BACKGROUND/PURPOSE: Traditional dental care, which includes long-term oral hygiene maintenance and scheduled dental appointments, requires effective communication between dentists and patients. In this study, a new system was designed to provide a platform for direct communication between dentists and patients. METHODS: A new mobile app, Dental Calendar, combined with cloud services specific for dental care was created by a team constituted by dentists, computer scientists, and service scientists. This new system would remind patients about every scheduled appointment, and help them take pictures of their own oral cavity parts that require dental treatment and send them to dentists along with a symptom description. Dentists, by contrast, could confirm or change appointments easily and provide professional advice to their patients immediately. In this study, 26 dentists and 32 patients were evaluated by a questionnaire containing eight dental-service items before and after using this system. Paired sample t test was used for statistical analysis. RESULTS: After using the Dental Calendar combined with cloud services, dentists were able to improve appointment arrangements significantly, taking care of the patients with sudden worse prosthesis (p < 0.05). Patients also achieved significant improvement in appointment reminder systems, rearrangement of appointments in case of sudden worse prosthesis, and establishment of a direct relationship with dentists (p < 0.05). CONCLUSION: Our new mobile app, Dental Calendar, in combination with cloud services, provides efficient service to both dentists and patients, and helps establish a better relationship between them. It also helps dentists to arrange appointments for patients with sudden worsening of prosthesis function.

A practice-based study on the survival of restored endodontically treated teeth.

INTRODUCTION: This retrospective study evaluated the survival of endodontically treated teeth (ETTs) and investigated factors influencing restoration and tooth survival. METHODS: Data from 795 ETTs were recorded, and success (restoration still intact) and survival (restoration intact or failed/repaired/replaced and tooth still in situ) were analyzed using Kaplan-Meier statistics. A multivariate Cox regression analysis was performed to assess the variables influencing success and survival. RESULTS: At the end of the observation period (mean observation time = 4.48 years), 45 teeth had been extracted (annual failure rate for survival = 1.9% at 9.6 years) and 114 restorations had received a restorative follow-up treatment (annual failure rate for success = 4.9% at 9.6 years). CONCLUSIONS: ETTs showed acceptable survival and success in the long-term. Variables showing significant influence on survival were the number of teeth in the dentition and the presence of decay at the moment the patient entered the practice.

A 24-month evaluation of amalgam and resin-based composite restorations: Findings from The National Dental Practice-Based Research Network.

BACKGROUND: Knowing which factors influence restoration longevity can help clinicians make sound treatment decisions. The authors analyzed data from The National Dental Practice-Based Research Network to identify predictors of early failures of amalgam and resin-based composite (RBC) restorations. METHODS: In this prospective cohort study, the authors gathered information from clinicians and offices participating in the network. Clinicians completed a baseline data collection form at the time of restoration placement and annually thereafter. Data collected included patient factors, practice factors and dentist factors, and the authors analyzed them by using mixed-model logistic regression. RESULTS: A total of 226 practitioners followed up 6,218 direct restorations in 3,855 patients; 386 restorations failed (6.2 percent) during the mean (standard deviation) follow-up of 23.7 (8.8) months. The number of tooth surfaces restored at baseline helped predict subsequent restoration failure; restorations with four or more restored surfaces were more than four times more likely to fail. Restorative material was not associated significantly with longevity; neither was tooth type. Older patient age was associated highly with failure (P < .001). The failure rate for children was 4 percent, compared with 10 percent for people 65 years or older. Dentist's sex and practice workload were associated significantly with restoration longevity. CONCLUSIONS: In this prospective cohort study, these factors were significantly predictive of failure for amalgam and RBC restorations: patient's age, a higher number of surfaces restored at baseline, the dentist's sex and the practice workload. Material choice was not significantly predictive in these early results. Practical Implications. If clinicians can recognize and identify the risk factors associated with early restoration failure, more effective treatment plans may be offered to the patient.

The up to 25-year survival and clinical performance of 2,340 high gold-based metal-ceramic single crowns.

PURPOSE: This study aimed to present the up to 25-year clinical performance and survival of 2,340 high gold-based metal-ceramic single crowns placed in a specialist prosthodontic practice. MATERIALS AND METHODS: All crowns provided to 670 patients between 1984 and 2008 were sequentially recruited. Each crown/tooth combination was given a prognostic evaluation at cementation. Patients were recalled in 2008 and 2009 for examination, and patient records were scrutinized for any retreatment. Estimated cumulative survival, standard error, and differences in survival between groups were calculated using the Kaplan-Meier method, Greenwood formula, and log-rank test, respectively. Crown status (six-field classification) was reported within 5-year groupings and for 7, 10, and 12 years. RESULTS: The up to 10-year and 25-year estimated survival rates of the 2,211 favorably rated crowns were 97.08% ± 0.45% and 85.40% ± 2.19%, respectively. The up to 12-year survival for crowns in the postimplant era was 94.4% ± 2.78%. No significant differences related to sex, tooth type, or tooth position were demonstrated. Nonvital teeth had lower overall survival rates than vital teeth, but not in crowns placed in the postimplant era. Actual 10-year outcomes closely matched the estimated 10-year survival. Biologic factors accounted for 101 of the 133 failures, while mechanical factors accounted for 8 failures and patient concerns accounted for 24 failures. Porcelain fracture requiring replacement occurred in 4 crowns. CONCLUSIONS: The clinical performance of the crowns was excellent. Biologic factors accounted for the majority of failures. Material stability was excellent. Patient complaints of unacceptable esthetics resulted in 22 crowns being replaced after a mean clinical service time of 14 years.

Adult Dental Health Survey 2009: common oral health conditions and their impact on the population.

Data from the Adult Dental Survey conducted in 2009/10 have recorded some major changes in the pattern of oral conditions in British adults. The change in the number of sound and untreated teeth in recent decades has been particularly marked in younger adults. Across all ages there were 17.9 sound and untreated teeth per dentate adult, but among the youngest (16-24-year-olds) it was 26.9 teeth indicating rapidly improving prospects for young adults compared with their predecessors. Between 1998 and 2009 the overall prevalence of caries of all types in England has fallen dramatically from 54% to 31% overall, but the number of teeth affected by caries among those people affected by decay is almost unchanged at around 2.7 affected teeth per person. Caries, and the reduction in caries, affected people of all ages. The rate of new restorations is correspondingly low and young adults in particular had fewer restorations than their predecessors. Much activity is now likely to be around repairing or extending existing restorations. By contrast 37% of dentate adults had crowns, up from 34% in 1998, averaging around three crowns per person among those who have crowns. A minority of British adults had a very healthy periodontal status (17%) and moderate periodontal disease (pockets of 4 mm to less than 6 mm) has also reduced markedly in the last decade, in line with measurably less plaque and more frequent brushing. However, more severe disease has increased slightly (from 6% to 9% of adults). The frequency of impact of poor oral health on people's lives has also reduced in the last decade. However, while clinical conditions are improving, there is a proportion of dentate adults that experience negative effects on their daily life frequently (16%) and/or severely (17%) due to their oral health; who are more likely to be those in a lower socioeconomic position and those with worse clinical status in terms of caries and periodontal disease.

Restorative material and other tooth-specific variables associated with the decision to repair or replace defective restorations: findings from The Dental PBRN.

OBJECTIVES: Using data from dentists participating in The Dental Practice-Based Research Network (DPBRN), the study had 2 main objectives: (1) to identify and quantify the types of restorative materials in the existing failed restorations; and (2) to identify and quantify the materials used to repair or replace those failed restorations. METHODS: This cross-sectional study used a consecutive patient/restoration recruitment design. Practitioner-investigators recorded data on consecutive restorations in permanent teeth that needed repair or replacement. Data included the primary reason for repair or replacement, tooth surface(s) involved, restorative materials used, and patient demographics. RESULTS: Data for 9875 restorations were collected from 7502 patients in 197 practices for which 75% of restorations were replaced and 25% repaired. Most of the restorations that were either repaired or replaced were amalgam (56%) for which most (56%) of the material used was direct tooth-coloured. The restorative material was 5 times more likely to be changed when the original restoration was amalgam (OR=5.2, p<.001). The likelihood of changing an amalgam restoration differed as a function of the tooth type (OR=3.0, p<.001), arch (OR=6.6, p<.001); and number of surfaces in the original restoration (OR=12.2, p<.001). CONCLUSION: The probability of changing from amalgam to another restorative material differed with several characteristics of the original restoration. The change was most likely to take place when (1) the treatment was a replacement; (2) the tooth was not a molar; (3) the tooth was in the maxillary arch; and (4) the original restoration involved a single surface.

Increasing the longevity of restorations by minimal intervention: a two-year clinical trial.

UNLABELLED: This investigation assessed the effectiveness of alternative treatments for the replacement of amalgam and resin-based composite restorations. Sixty-six patients (age 18 to 80 years, mean = 26.6) with 271 (amalgam [n = 193] and resin-based composite [n = 78]) defective restorations were randomly assigned to one of five different treatment groups: A) Repair (n = 27); B) Sealing of margins (n = 48); C) Refurbishing (n = 73); D) Replacement (n = 42) and E) Untreated (n = 81). USPHS/Ryge criteria were used to determine the quality of the restorations. Two calibrated examiners (Cohen's Kappa 0.74) assessed the restorations independently at the beginning of the study (baseline) and at two years after treatment using seven parameters from the USPHS/Ryge criteria (Marginal Adaptation, Anatomic Form, Roughness, Marginal Stain, Occlusal Contact, Secondary Caries and Luster). RESULTS: Two-hundred and fifty-six restorations (178 amalgam and 78 resin-based composite) were examined at the two-year recall exam. The sealing of marginal defects showed significant improvements in marginal adaptation (p < 0.05). Refurbishing of the defective restorations significantly improved anatomic form (p < 0.0001), luster (p < 0.016), marginal adaptation (p < 0.003) and roughness (p < 0.0001). The repair significantly improved anatomic form (p < 0.002) and marginal stain (p < 0.002). Replacement showed significant improvements for all parameters (p < 0.05). The Untreated group showed significant deterioration on marginal adaptation (p < 0.013). CONCLUSIONS: The two-year recall examination showed that sealant, repair and refurbishing treatments improved the clinical properties of defective amalgam and resin-based composite restorations by increasing the longevity of the restorations with minimal intervention.

A 10-year longitudinal study of fixed prosthodontics: clinical characteristics and outcome of single-unit metal-ceramic crowns.

PURPOSE: The purpose of this study was to report on the clinical characteristics and outcome of 688 single-unit metal-ceramic crowns placed in a specialist prosthodontic practice between January 1984 and December 1992. MATERIALS AND METHODS: Clinical and laboratory techniques were standardized and patients were recalled by the author between June and December of 1993. The outcome of all crowns was allocated to one of 6 fields in this assessment period. RESULTS: Clinical review examination by the author covered 87% of the crowns. Of these, 52% had been in service for 5 to 10 years and 48% for less than 5 years but more than 1 year; 67% of the crowns were placed on vital teeth and 94% were given a "good prognosis" rating at examination. The repair and failure rates of crowns in the 5 to 10 years in clinical service group were both 3%. Crowns on nonvital teeth in the same grouping had a significantly greater failure rate (5%) than crowns on vital teeth (1%), and anterior teeth had a significantly greater retreatment rate than posterior teeth. Retreatment for all 25 crowns occurred within 66 months after cementation. Tooth fracture accounted for 56% of retreatments, while caries and loss of retention accounted for only 24% of retreatments; 2% of initially vital teeth were endodontically treated during the survey period. CONCLUSION: Single-unit metal-ceramic crowns have a high expectancy of exceeding 10 years of clinical service when the described clinical and laboratory protocol is applied.

Complications and maintenance requirements of implant-supported prostheses provided in a UK dental hospital.

AIM: To assess the nature, timing and frequency of complications associated with implant therapy and to assess maintenance requirements of implant-supported prostheses. DESIGN: Retrospective analysis. SETTING: The Dental Hospital in Newcastle upon Tyne. METHOD: Dental records of 60 patients provided with implant-supported prostheses were examined. Data were compiled on the number of fixtures placed per patient, the type of prosthesis provided, complications during the surgical and prosthodontic phases, and peri-implant soft tissue complications. RESULTS: 66 prostheses were placed on 236 fixtures over a 6-year period. Surgical complications included fixture loss (n = 6), dysaesthesia (n = 12), and the need for a guided tissue regeneration procedure (n = 10). Common maintenance requirements were tightening of components (n = 11), clip replacement (n = 7) and repair of conventional prostheses opposing implant supported prostheses (n = 7). Plaque control was unsatisfactory with almost half of the subjects requiring intensive oral hygiene instruction and scaling at the first post placement review. CONCLUSIONS: Prosthodontic maintenance requirements were high, particularly during the first year. Surgical complications were relatively infrequent. A case was made for a rigorous oral hygiene programme to reduce the potential for fixture loss through neglect. The financial cost associated with the maintenance of implant-supported prostheses should be incorporated in their overall funding.

Surface treatment techniques for resin composite repair.

PURPOSE: To compare bond strengths of fresh resin composites to previously polymerized ("aged") composites following various surface treatments. MATERIALS AND METHODS: Eighty Pertac Hybrid (PH) and an equal number of Silux Plux (SLX) specimens were fabricated and stored for 1 week prior to surface treatment. The specimens were then polished and stored for an additional 24 hours prior to final surface treatment. The surface treatments included use of one of the following: (1) diamond bur (DB), (2) microetcher with 50 microns Al2O3@80 psi pressure (ME), (3) high-pressure air abrasion with 27 microns Al2O3@psi, (KCP), or (4) low-pressure silicate ceramic deposition using 30 microns particles@34 psi (CJ-S) with a microetcher. Half of the samples were treated with a silanating agent. Fresh resin composite (same type as used for the aged specimen) was bonded to the treated surfaces, and specimens were then stored 24 h and thermocycled 300 x at 5 degrees and 55 degrees C prior to testing for shear bond strength. Two-way ANOVA was used to determine significant differences between mean shear bond strengths for both composite materials. RESULTS: Significant differences were found between the groups for both surface treatment and silane use (P < 0.05). The interaction between the two main effects was also significant (P < 0.05). Overall, the highest bond strengths were found when the low-pressure silicate ceramic deposition system (CJ-S) was used, with or without silane.

A prospective study on the maintenance of implant prostheses in private practice.

This study examined the adjustments, repairs, time, and costs required to maintain 69 implant prostheses in private prosthodontic practice for an average of 22 months after placement. For the removable prosthesis design, the most common adjustment was contouring the prosthesis and the most common repair was retentive component replacement. Screw tightening or fracture repair were the most frequently needed modifications for fixed implant prostheses. Each removable implant prosthesis averaged four times as many postplacement adjustments and almost twice as many repairs as did each fixed implant prosthesis, and the mean length of each maintenance appointment was also longer for removable prostheses. Mean repair costs were approximately 60% higher for the removable design.