Mediotrusive Occlusal Contacts: Best Evidence Consensus Statement.

PURPOSE: The impact of mediotrusive (MT) occlusal contacts has been a topic of controversy and confusion in both clinical practice and in the dental literature. The purpose of this Best Evidence Consensus Statement was to explore whether MT interferences are harmful in the natural or therapeutic occlusion directed by 4 focus questions relating to prevalence, jaw function, jaw dysfunction and biomechanical models. MATERIALS AND METHODS: An electronic search in October 2020 sought evidence in MEDLINE (Ovid) using (mediotrus* OR nonworking side OR nonworking contact OR balancing side OR interfer* side OR premature contact) in the multipurpose (.mp) search field; and in Google Scholar using permutations of the above. Supplementary articles were sourced from the associated reference lists. There was no language restriction. The search yield was reviewed in duplicate. RESULTS: The electronic search identified 420 articles. Following screening, 164 were selected for eligibility assessments. Of these, 47 were included in the current paper. CONCLUSIONS: Non-standardized nomenclature and methodology is used to identify MT interferences in patient populations, with resultant prevalence varying from 0% to 77%, (median = 16%). MT interferences may alter the biomechanics of mandibular function. Together with the presence of repeated high loads resultant strain can manifest as pathophysiology of the temporomandibular joint and associated muscle structures. MT interferences should be avoided in any therapeutic occlusal scheme to minimize pulpal, periodontal, structural and mechanical complications or exacerbation of temporomandibular disorders (TMDs). Naturally occurring molar MT interferences should be eliminated only if signs and symptoms of TMDs are present. Literature supports there being a biomechanical basis which can explain how MT interferences may affect temporomandibular joint morphology and jaw function.

Comparison of Corrosion Products From Implant and Various Gold-Based Abutment Couplings: The Effect of Gold Plating.

This study compared titanium (Ti), palladium (Pd), platinum (Pt), and gold (Au) ion release following induced accelerated tribocorrosion from three Au alloy abutment groups coupled with Ti implants over time; investigated contacting surface structural changes; and explored the effect of Au plating. Three abutment groups, G (n = 8, GoldAdapt, Nobel Biocare), N (n = 8, cast UCLA, Biomet3i), and P (n = 8, cast UCLA, Biomet3i, Au plated), coupled with implants (Nobel Biocare), immersed in 1% lactic acid, were cyclically loaded. Ions released (ppb) at T1, T2, and T3, simulating 3, 5, and 12 months of function, respectively, were quantified by inductively coupled plasma mass spectrometry (ICP-MS) and compared. Surface degradation and fretted particle composition after T3 were evaluated with scanning electron microscopy and energy-dispersive X-ray spectroscopy (SEM/EDX). ICP-MS data were nonparametric, expressed as medians and interquartile ranges. SEM/EDX showed pitting, crevice corrosion, and fretted particles on the components. Released ion concentrations in all groups across time significantly decreased for Pd (P < .001, median range: 1.70-0.09), Pt (P = .021, 0.55-0.00), and Au (P < .001, 1.01-0.00) and increased for Ti (P = .018, 2.49-5.84). Total Ti release was greater than other ions combined for G (P = .012, 9.86-2.30) and N (P < .001, 13.59-5.70) but not for P (P = .141, 8.21-3.53). Total Ti release did not differ between groups (P = .36) but was less variable across group P. On average, total ion release was 13.77 ppb (interquartile range 8.91-26.03 ppb) across the 12-month simulation. Tribocorrosion of Ti implants coupled with Au abutments in a simulated environment was evidenced by fretted particles, pitting, and crevice corrosion of the coupling surfaces and release of ions. More Ti was released compared with Pd, Pt, and Au and continued to increase with time. Abutment composition influenced ion release. Au-plated abutments appeared to subdue variation in and minimize high-concentration spikes of titanium.

Combined use of splinted labial lithium disilicate veneers and a bonded nickel-chromium alloy palatal splint for tooth stabilization: A clinical report with 4-year follow-up.

This clinical report describes the restoration of severely compromised maxillary teeth in a 20-year-old woman secondary to excessive root shortening and minimal bone support but surrounded by healthy and esthetic soft tissues. The maxillary bone volume precluded provision of an implant-supported fixed or removable dental prosthesis without extensive grafting procedures. Splinted labial lithium disilicate veneers and a bonded nickel-chromium alloy palatal splint were used to stabilize and retain the structurally compromised maxillary teeth. At the 4-year review, the splinted veneers remained intact.

Intra- and inter-examiner agreement when assessing radiographic implant bone levels: Differences related to brightness, accuracy, participant demographics and implant characteristics.

OBJECTIVES: Evaluate intra- and inter-examiner agreement of radiographic marginal bone level (MBL) assessment around Brånemark single implants; and whether agreement related to radiograph brightness, discrimination level (accuracy), participant demographics or implant characteristics. MATERIALS AND METHODS: Seventy-four participants assessed MBLs of 100 digital radiographs twice with normal brightness, and twice with increased brightness. Intra-examiner agreement with and without increased brightness to the same thread, and within one thread; and inter-examiner agreement as compared with the group (defined by the mode) for the first assessments with and without increased brightness, to the same thread, and within one thread were calculated with Cohen's Kappa. Relationships between agreement, thread discrimination level (accuracy), brightness, participant and implant characteristics were explored. RESULTS: When assessing 100 "Normal" radiographs twice, a participant on average assessed 24% differently to themselves (poor intra-examiner agreement, median Kappa 0.58, range 0.21-0.82); and 28% differently to other participants (poor inter-examiner agreement, median Kappa 0.53, range 0.05-0.80). Agreement within examiners improved when radiographs were "Bright" (median Kappa 0.58 vs. 0.62, p < 0.001, accuracy to same thread; median Kappa 0.94 vs. 0.96, p < 0.001, accuracy within one thread). Agreement between examiners was neither better nor worse when radiographs were "Bright" (median Kappa 0.53 vs. 0.55, p = 0.64, accuracy to same thread; median Kappa 0.93 vs. 0.93, p = 0.23, accuracy within one thread). Intra- and inter-examiner agreements were lower when accuracy to the same thread was required (p < 0.001, p < 0.001). Neither intra- nor inter-examiner agreement related to age, time since graduation, specialty, viewing device, implant experience, external hex familiarity, periimplantitis treatment experience, implant location or width (p-values 0.05-0.999). Intra-examiner agreement increased across dental assistants (n = 11), general dentists (n = 16) and specialists (n = 47) ("Bright" assessments, p = 0.045, median Kappa's 0.55, 0.60, 0.65 respectively); and for females (n = 8, males = 58) ("Normal" assessments, p = 0.019, median 0.68 vs. 0.55), but female numbers were low. CONCLUSIONS: Agreement within and between examiners when assessing MBLs was poor. Disagreement occurred around 25% of the time, potentially affecting consistent disease assessments. No participant or implant characteristic clearly affected agreement. Brighter radiographs improved intra-examiner agreement. Overall, perceived MBL changes below 1 mm are likely due to human, not biological variation.

Satisfaction and Patient-Related Outcomes in 128 Patients with Single Implant Crowns In Situ for up to 14 Years.

PURPOSE: To assess patient satisfaction and patient-related outcomes across the domains of appearance, cleansibility, and costs; the perceived value and worth when single implant crowns (SICs) had been in situ up to 14 years; whether satisfaction differed between patients; and whether certain characteristics might affect the questionnaire response rate. MATERIALS AND METHODS: Patients treated at a private prosthodontic practice between 2001 and 2014 (n = 207) who received a SIC (n = 256) were prospectively included. A previously validated patient satisfaction questionnaire (PSQ) exploring patient-centered outcomes was mailed to participants. Demographic (sex, age) and treatment data (number of SICs, time in situ, failure experience, complication experience) were collected. Visual analog scale (VAS) responses were converted to percentages. Differences between respondents and nonrespondents, differences in satisfaction between prosthesis placement and survey date, and differences with respect to demographic and treatment data were assessed. Averages were medians bounded by interquartile ranges. Statistical significance was set at P = .05. RESULTS: Respondents (n = 128, 61.8%) and nonrespondents (n = 79, 38.2%) had similar demographic and treatment characteristics. Prostheses had been in situ for up to 14 years (median, 5 years; interquartile range [IQR], 24 to 96 months). Participants reported that treatment met their expectations (median, 93%; IQR, 85% to 100%); they reported high satisfaction with tooth color, tooth contour, peri-implant mucosa, appearance overall, and ease of cleaning (medians ranging from 90.5% to 95%, IQR ranging from 80% to 100%) and medium satisfaction with costs when prostheses were placed (median, 50%; IQR, 29% to 80%). Satisfaction with tooth contour, peri-implant tissues, overall appearance, and costs significantly improved over time (96%, 92.5%, 91.7%, and 75%, respectively; P < .001 to P = .049). Levels of satisfaction did not differ by sex, number of implants, survival, complications, number of complications, and time in situ. Younger patients were less satisfied with the overall appearance and costs than older patients (P = .004, P = .007, respectively). All patients would choose to undergo treatment again and would recommend it to a friend. CONCLUSION: Patients with SICs that were in situ up to 14 years who responded to the validated PSQ were highly satisfied with the appearance and cleansibility, noted improvements in peri-implant tissue contours, and found the treatment to be valuable and worthwhile. They reported that upfront costs were high, but this concern decreased when the SICs had been in the mouth for a period of time.

The Up-to-14-Year Survival and Complication Burden of 256 TiUnite Implants Supporting One-Piece Cast Abutment/Metal-Ceramic Implant-Supported Single Crowns.

PURPOSE: To assess the estimated cumulative survival (ECS) and explore the technical and biologic complications of 256 TiUnite implants (Nobel Biocare) supporting one-piece cast abutment/metal-ceramic implant-supported single crowns (ISCs) in situ for up to 14 years. MATERIALS AND METHODS: A prospective sequentially recruited cohort of 207 patients received 256 metal-ceramic ISCs on TiUnite implants between 2001 and 2014. All but 24 patients with 27 crowns were clinically evaluated between January 2014 and April 2015 in conjunction with or in addition to their tailored maintenance program. Radiographs were obtained, and any previously recorded treatments associated with the crowns were tabulated. The ECS and standard errors were calculated with the life table actuarial method and Greenwood's formula, respectively. The log rank test was applied to assess differences between anterior and posterior crowns. Complication incidence, severity, and economic burden, measured in time/cost accounting units (TAUs), were tallied and compared descriptively. Independent groups were compared with the Mann-Whitney U test and related groups with the Wilcoxon Signed Rank Test. RESULTS: The mean clinical service time of the crowns was 5.61 years (44 ≥ 10 years). The 14-year ECS was 95.95% ± 3.20% with no significant difference between anterior and posterior prostheses. Only seven implants lost marginal bone ≥ one thread from the time of crown insertion. There were 30 nonterminal complications (16 biologic, 14 mechanical). The associated economic burden was low (n = 35 TAUs). CONCLUSION: High gold-alloy one-piece cast abutment/metal-ceramic ISCs on TiUnite implants exhibited excellent longevity and few complications over 14 years.

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.

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.

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.

A systematic review and meta-analysis of the survival of feldspathic porcelain veneers over 5 and 10 years.

PURPOSE: This systematic review reports on the survival of feldspathic porcelain veneers. MATERIALS AND METHODS: The Cochrane Library, MEDLINE (OVID), Embase, Web of Knowledge, selected journals, clinical trials registers, and conference proceedings were searched independently by two reviewers. Academic colleagues were also contacted to identify relevant research. Inclusion criteria were human cohort studies (prospective and retrospective) and controlled trials assessing outcomes of feldspathic porcelain veneers in more than 15 patients and with at least some of the veneers in situ for 5 years. Of 4,294 articles identified, 116 studies underwent full-text screenings and 69 were further reviewed for eligibility. Of these, 11 were included in the qualitative analysis and 6 (5 cohorts) were included in meta-analyses. Estimated cumulative survival and standard error for each study were assessed and used for meta-, sensitivity, and post hoc analyses. The I2 statistic and the Cochran Q test and its associated P value were used to evaluate statistical heterogeneity, with a random-effects meta-analysis used when the P value for heterogeneity was less than .1. Galbraith, forest, and funnel plots explored heterogeneity, publication patterns, and small study biases. RESULTS: The estimated cumulative survival for feldspathic porcelain veneers was 95.7% (95% confidence interval [CI]: 92.9% to 98.4%) at 5 years and ranged from 64% to 95% at 10 years across three studies. A post hoc meta-analysis indicated that the 10-year best estimate may approach 95.6% (95% CI: 93.8% to 97.5%). High levels of statistical heterogeneity were found. CONCLUSIONS: When bonded to enamel substrate, feldspathic porcelain veneers have a very high 10-year survival rate that may approach 95%. Clinical heterogeneity is associated with differences in reported survival rates. Use of clinically relevant survival definitions and careful reporting of tooth characteristics, censorship, clustering, and precise results in future research would improve metaanalytic estimates and aid treatment decisions.

The up to 21-year clinical outcome and survival of feldspathic porcelain veneers: accounting for clustering.

PURPOSE: This study aimed to investigate the clinical outcome and estimated cumulative survival rate of feldspathic porcelain veneers in situ for up to 21 years while also accounting for clustered outcomes. MATERIALS AND METHODS: Porcelain veneers(n = 499) placed in patients (n = 155) by a single prosthodontist between 1990 and 2010 were sequentially included, with 239 veneers (88 patients) placed before 2001 and 260 veneers (67 patients) placed thereafter. Nonvital teeth, molar teeth, or teeth with an unfavorable periodontal prognosis were excluded. Preparations had chamfer margins, incisal reduction, palatal overlap, and at least 80% enamel. Feldspathic veneers from refractory dies were etched (hydrofluoric acid), silanated, and bonded. Many patients received more than 1 veneer (mean: 5.8 ± 4.3). Clustered outcomes were accounted for by randomly selecting (random table) 1 veneer per patient for analysis. Clinical outcome (success, survival, unknown, dead, repair, failure) and Kaplan-Meier estimated cumulative survival were reported. Differences in survival were analyzed using the log-rank test. RESULTS: For the random sample of veneers (n = 155), the estimated cumulative survival rates were 96% ± 2% (10 years) and 96% ± 2% (20 years). For the entire sample, the survival rates were 96% ± 1% (10 years) and 91% ± 2% (20 years). Survival did not statistically differ between these groups (P = .65). Seventeen veneers in 8 patients failed, 75 veneers in 30 patients were classified as unknown, and 407 veneers in 130 patients survived. Multiple veneers in the same mouth experienced the same outcome, clustering the results. CONCLUSIONS: Multiple dental prostheses in the same mouth are exposed to the same local and systemic factors, resulting in clustered outcomes. Clustered outcomes should be accounted for during analysis. When bonded to prepared enamel substrate, feldspathic porcelain veneers have excellent long-term survival with a low failure rate. The 21-year estimated cumulative survival for feldspathic porcelain veneers bonded to prepared enamel was 96% ± 2%.

Changes in the outcome of metal-ceramic tooth-supported single crowns and FDPs following the introduction of osseointegrated implant dentistry into a prosthodontic practice.

PURPOSE: The aim of this study was to prospectively analyze the effect that the incorporation of osseointegrated implant dentistry had on the outcome of metal-ceramic tooth-supported prostheses that had been in situ for 5 to 10 years. MATERIALS AND METHODS: The 10-year estimated (Kaplan-Meier) cumulative survival of metal-ceramic tooth-supported single crowns (TSCs) and metal-ceramic tooth-supported fixed dental prostheses (TFDPs) provided for all patients treated at two time periods was determined and statistically compared (log-rank test). Prostheses in group 1 (404 TSCs and 433 TFDP abutments in 189 TFDPs) were cemented between January 1989 and December 1993, with the outcome determined in 1998. Prostheses in group 2 (539 TSCs and 354 TFDP abutments in 142 TFDPs) were cemented between January 1997 and December 2001, with the outcome determined in 2006. A 500% increase in implants restored occurred between the end of group 1 and group 2 time periods. RESULTS: For TSCs, comparison between groups showed a significantly better survival in group 2 than in group 1 for nonvital TSCs (P = .001), nonvital maxillary anterior teeth (P = .003), nonvital maxillary lateral incisors (P = .008), and nonvital premolars (P = .013). Comparison within groups showed nonvital TSCs had a significantly decreased survival compared to vital TSCs in group 1 (P < .001), but not in group 2 (P = .48). Overall, the estimated cumulative 10-year survival of TSCs in group 2 was 94% +/- 3%. For TFDPs, comparison between groups showed a significantly better survival for nonvital abutments in group 2 than in group 1 (P = .049). Comparison within groups showed nonvital TFDP abutments had a significantly decreased survival compared to vital TFDP abutments in group 1 (P = .001), but not in group 2 (P = .377). Overall, group 2's estimated cumulative 10-year survival for all TFDPs was 90% +/- 6% and for three-unit TFDPs was 97% +/- 2%. Teeth in group 2 failed less through fracture and periodontal disease than those in group 1. CONCLUSIONS: The incorporation of osseointegrated implant dentistry has resulted in a significant improvement in the survival of TSCs and TFDP abutments, nonvital and vital teeth having equivalent survivals for TSCs and TFDPs, and a decrease in supporting-tooth failure through fracture and periodontal disease.

Changes in patient and FDP profiles following the introduction of osseointegrated implant dentistry in a prosthodontic practice.

PURPOSE: This paper describes the effects of implant-related dentistry on patient profiles and the types of fixed dental prostheses provided in clinical practice. MATERIALS AND METHODS: All implant- and tooth-supported prostheses provided in a prosthodontic practice between 1984 and 2007 were tabulated. Incidence was analyzed in relation to gender, age at time of prostheses insertion, and prostheses type. RESULTS: Tooth-supported single crowns (TSCs) and tooth-supported fixed dental prostheses (TFDPs) were involved in 97% of treatments requiring fixed dental prostheses from 1984 to 1991. From 1991 to 2007, however, a marked increase in the number of implants restored directly corresponded with a decrease in the number of TFDPs so that by 2007, implant-supported fixed dental prostheses (IFDPs) accounted for 81% of all tooth replacements. Between 1984 and 2007 the incidence of TFDPs was 61% in females and 39% in males, whereas the incidence of IFDPs was 55% in females and 45% in males. IFDPs were also involved in 35% of restorations in patients under 31 years of age and TFDPs in 19%. In the under-21 years age group, IFDPs were more common in females (9%) than males (4%), but in the 21 to 30 years age group they were more common in males (21%) than females (13%). There was a decrease in three-unit TFDPs, in TFDPs with four or more pontics and those not satisfying Ante's Law, and in teeth used that had been subjectively assessed to have an unfavorable 10-year prognosis at the time of prosthesis insertion. CONCLUSIONS: The incorporation of osseointegrated implant dentistry into a clinical practice has resulted in changes in the patient profile and type of fixed dental prostheses provided, including a decrease in the use of TFDPs; an increase in the referral of patients under 31 years of age; a decrease in three-unit, long-span, and complex TFDPs; and a decrease in tooth abutments assessed to be structurally or biologically compromised.

Profiles of 500 patients who did and 486 patients who did not respond to a prosthodontic treatment questionnaire.

PURPOSE: This paper aims to analyze the demographic and prosthodontic treatment differences between patients who did and did not respond to a mailed questionnaire. MATERIALS AND METHODS: All living patients who received tooth- and implant-related fixed prosthodontic treatment between January 1984 and June 2005 (n = 986) in one private prosthodontic practice were mailed a questionnaire regarding their prosthodontic treatment. Demographic data (sex, age) and treatment data (survival, type of treatment, time in situ, number of units, number of treatments) for responding and nonresponding patients were collected from patient files and analyzed. Statistical significance was set at P = .05. RESULTS: There were 500 responding patients (50.7%) with 2,702 fixed prosthodontic units (60.02%) and 486 nonresponding patients (49.3%) with 1,800 fixed prosthodontic units (39.98%). Prostheses were in situ from 1 to 20 years, with the average time in situ for respondents of 7.47 +/- 5.48 years and 6.5 +/- 5.21 years for nonrespondents. Responding and nonresponding patients had similar sex distributions (P = .61), Kaplan-Meier 10-year estimated cumulative survivals (92.2 +/- 1.72% and 91.5 +/- 1.92%; P = .13), and received a similar distribution of treatment prostheses (implant versus tooth) (P = .24). However, responding patients were significantly older (P < .001), had their prostheses in situ for a greater length of time (P < or = .01), received more prosthetic units (P < .001), and underwent more treatment episodes (P < .001) than nonresponding patients. CONCLUSIONS: Patient questionnaires provide valid and unique research information. Prosthesis outcomes for patients who did and did not respond to the questionnaire were the same. Treatment outcomes of patients who attend review appointments and those who are lost to follow-up cannot be assumed to be different. Demographic- and treatment-related characteristics of responding patients indicated that an enhanced provider-patient rapport was a principal motivator for responding to the questionnaire.

An up to 15-year longitudinal study of 515 metal-ceramic FPDs: Part 2. Modes of failure and influence of various clinical characteristics.

PURPOSE: This study reported on the modes of failure and the influence of various clinical characteristics on the outcome of 515 metal-ceramic fixed partial dentures (FPD) involving 1,209 abutment and 885 pontics placed by one operator in a specialist prosthodontic practice between January 1984 and December 1997. MATERIALS AND METHODS: Fifty-three percent of maxillary and 84% of mandibular FPDs involved one or more nonrigid abutment-pontic connections. Patients were recalled in 1993 (review 1) and 1998 (review 2) and clinically examined by the author. The modes of failure and influence of clinical characteristics, including abutment-pontic connection, post design in nonvital abutments, and regularity of professional maintenance, were evaluated. RESULTS: At review 2, 80% of the FPDs were still in function, while 9% required retreatment. Tooth fracture accounted for 38%, caries for 11%, loss of retention for 13%, and periodontal breakdown for 27% of retreatments. Nonrigid abutment-pontic connection in posterior FPDs and regular professional maintenance were associated with significantly reduced failure rates. Except in posterior molars, there was no difference in failure rates between parallel-sided preformed stainless steel serrated posts and cast-gold alloy posts. CONCLUSION: Tooth fracture was the most common reason for retreatment of the FPDs, although the rate of periodontal breakdown and caries increased significantly with time. Nonrigid abutment-pontic connection and regular professional maintenance were associated with significantly reduced failure rates. Post design and composition were not related to outcome.

An up to 15-year longitudinal study of 515 metal-ceramic FPDs: Part 1. Outcome.

PURPOSE: This study reports on the outcome of 515 metal-ceramic fixed partial dentures (FPD) involving 1,209 abutments and 885 pontics placed by one operator in a specialist prosthodontic practice between January 1984 and December 1997. MATERIALS AND METHODS: Clinical and laboratory protocol was kept constant as much as was practical. Each FPD and abutment was given a subjective prognostic rating at the time of cementation. Patients were recalled in 1993 (review 1) and 1998 (review 2). Clinical examination by the author covered 85% of 342 FPDs at review 1 and 82% of 515 FPDs at review 2. At review 2, 37% had been in clinical service for 5 to 10 years (group b), and 34% had been in service for 10 to 15 years (group c). An objective classification protocol was used to assess outcome. RESULTS: At review 2, the FPDs had failure rates of 2%, 7%, and 11% in groups a, b, and c, respectively. There was a significant increase in the failure rate of group c at review 2 (11%) compared with review 1 (5%). Cumulative survival analysis indicated that FPDs have an expected survival rate of 96%, 87%, and 85% at 5, 10, and 15 years, respectively. The applied prognostic rating proved more accurate as clinical service time increased. Outcome was not related to number of units. Cantilevered FPDs, nonvital abutments, and anterior abutments had significantly greater failure rates. Of initially vital abutments, 2% were subsequently endodontically treated. CONCLUSION: Tooth-supported FPDs have an expected survival rate of 85% at 15 years when the described clinical and laboratory protocol is applied.