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.

Time-to-event survival statistics in ophthalmology: Methodological research.

IMPORTANCE: Understanding the outcomes of interventions over time is essential for clinical decision making in surgical specialties. BACKGROUND: Analysis of survival time (or time to event) is complicated when loss to follow up occurs. This article explores transparent data analysis methods where missing ("censored") data are present. DESIGN: Manual search of the top 20 Ophthalmology journals from a recent year of the established literature (2014). SAMPLES: A total of 4565 articles were identified, of which 218 reported outcomes of treatment over time in humans. METHODS: Pertinent details to assist the use of Kaplan-Meier and life table actuarial statistics are explained, and criteria that define whether each has high, acceptable or poor quality are explored. The quality of reporting from the literature sample is analysed. MAIN OUTCOME MEASURES: Reporting quality of survival curves and life tables from each sampled article is assessed according to the established criteria. RESULTS: In total, 31.2% of samples (n = 68) presented survival curves, 53.2% (n = 116) presented life tables, 22% (n = 48) presented both, whilst 46.8% (n = 102) presented neither; 2% of survival curves and 13% of life tables were high quality, with quality of life tables significantly better than survival curves (P = .0042). 90.36% (n = 197) of articles reported time to event data which was classified as poor: due to poor analysis of survival curves (n = 50, 43.10%) poor analysis of life tables (n = 45, 66.18%); and complete omission of survival graphics (n = 102, 46.97%). CONCLUSIONS AND RELEVANCE: Ophthalmology research that follows patient outcomes over time can be analysed with "time-to-event" statistics, and reported with transparency. This analysis showed that important contextural information was omitted from 90% of ophthalmic studies, and this could impact patient decision making.

Group 4 ITI Consensus Report: Risks and biologic complications associated with implant dentistry.

OBJECTIVES: The aim of Working Group 4 was to address topics related to biologic risks and complications associated with implant dentistry. Focused questions on (a) diagnosis of peri-implantitis, (b) complications associated with implants in augmented sites, (c) outcomes following treatment of peri-implantitis, and (d) implant therapy in geriatric patients and/or patients with systemic diseases were addressed. MATERIALS AND METHODS: Four systematic reviews formed the basis for discussion in Group 4. Participants developed statements and recommendations determined by group consensus based on the findings of the systematic reviews. These were then presented and accepted following further discussion and modifications as required by the plenary. RESULTS: Bleeding on probing (BOP) alone is insufficient for the diagnosis of peri-implantitis. The positive predictive value of BOP alone for the diagnosis of peri-implantitis varies and is dependent on the prevalence of peri-implantitis within the population. For patients with implants in augmented sites, the prevalence of peri-implantitis and implant loss is low over the medium to long term. Peri-implantitis treatment protocols which include individualized supportive care result in high survival of implants after 5 years with about three-quarters of implants still present. Advanced age alone is not a contraindication for implant therapy. Implant placement in patients with cancer receiving high-dose antiresorptive therapy is contraindicated due to the associated high risk for complications. CONCLUSIONS: Diagnosis of peri-implantitis requires the presence of BOP as well as progressive bone loss. Prevalence of peri-implantitis for implants in augmented sites is low. Peri-implantitis treatment should be followed by individualized supportive care. Implant therapy for geriatric patients is not contraindicated; however, comorbidities and autonomy should be considered.

Clinical outcomes of peri-implantitis treatment and supportive care: A systematic review.

OBJECTIVES: To report the clinical outcomes for patients with implants treated for peri-implantitis who subsequently received supportive care (supportive peri-implant/periodontal therapy) for at least 3 years. MATERIAL AND METHODS: A systematic search of multiple electronic databases, grey literature and hand searching, without language restriction, to identify studies including ≥10 patients was constructed. Data and risk of bias were explored qualitatively. Estimated cumulative survival at the implant- and patient-level was pooled with random-effects meta-analysis and explored for publication bias (funnel plot) at different time intervals. RESULTS: The search identified 5,761 studies. Of 83 records selected during screening, 65 were excluded through independent review (kappa = 0.94), with 18 retained for qualitative and 13 of those for quantitative assessments. On average, studies included 26 patients (median, IQR 21-32), with 36 implants (median, IQR 26-45). Study designs (case definitions of peri-implantitis, peri-implantitis treatment, supportive care) and population characteristics (patient, implant and prosthesis characteristics) varied markedly. Data extraction was affected by reduced reporting quality, but over 75% of studies had low risk of bias. Implant survival was 81.73%-100% at 3 years (seven studies), 74.09%-100% at 4 years (three studies), 76.03%-100% at 5 years (four studies) and 69.63%-98.72% at 7 years (two studies). Success and recurrence definitions were reported in five and two studies respectively, were heterogeneous, and those outcomes were unable to be explored quantitatively. CONCLUSION: Therapy of peri-implantitis followed by regular supportive care resulted in high patient- and implant-level survival in the medium to long term. Favourable results were reported, with clinical improvements and stable peri-implant bone levels in the majority of patients.

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.

In vitro comparison of guided versus freehand implant placement: use of a new combined TRIOS surface scanning, Implant Studio, CBCT, and stereolithographic virtually planned and guided technique.

Implant placement requires precise planning and execution to avoid collision with critical anatomical structures. Technology advances may improve placement outcomes. The purpose of this study was to trial and measure in an in vitro environment the accuracy of placing a single dental implant in the planned position using a specific guided surgery technique compared with a freehand surgery technique. The dental model of a patient missing tooth 16 was printed 30 times (EnvisionTEC 3Dent). Each print was scanned (TRIOS color scanner) to create a 3D surface model, and radiographed (Gendex CB-500) to create cone beam computed tomography (CBCT) data. The surface data and CBCT data were merged (Implant Studio software), and a Straumann RC bone level Ø 4.1 × 8 mm implant placement was planned. A surgical guide was printed (Stratasys OrthoDesk) for each case (n = 30). Simulated cases were assigned to Group A (guided) or Group B (freehand, where the fabricated guide was discarded). Implants were placed, and the models rescanned (TRIOS). The new data was superimposed on the original data, and the surgical implant location compared with the planned position for each model (Convince software) by a researcher blinded to group allocation. Differences in angulation (degrees); shoulder, apex, and depth displacements (mm); and direction of displacement were assessed with Mann-Whitney U and Fisher exact tests. Data was expressed as medians bounded by interquartile ranges (IQRs). Implant angulation and apical displacement were significantly closer to the planned position in the guided group compared with the freehand group (3.91 degrees: IQR 2.45 to 5.38 degrees vs 8.82 degrees: IQR 4.84 to 9.84 degrees, P = 0.005; and 0.87 mm: IQR 0.53 to 1.11 mm vs 1.48 mm: IQR 1.14 to 1.72 mm, P < 0.001, respectively). Implant shoulder displacement, depth displacements, and direction of displacement did not differ between the groups. Within the in vitro environment, merged 3D surface scan data and 3D CBCT scan data can be used to plan and guide implant placement with greater accuracy than with the freehand technique.

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.

How to Find Dental Survival Articles: Using the New Search Strategies.

Clinicians and readers rely on accurate identification of articles to answer clinical questions and explore hypotheses. Commonly, these questions relate to the outcome and survival of dental treatments. Errors in indexing and inconsistencies in descriptions of these studies have meant that such articles are difficult to locate. To help address this problem, sensitive, precise and optimized electronic search strategies have been developed, and this article aims to explain how these new strategies can be used. These electronic search strategies have been shown to improve the identification of dental survival analyses.

Search Strategy to Identify Dental Survival Analysis Articles Indexed in MEDLINE.

PURPOSE: Articles reporting survival outcomes (time-to-event outcomes) in patients over time are challenging to identify in the literature. Research shows the words authors use to describe their dental survival analyses vary, and that allocation of medical subject headings by MEDLINE indexers is inconsistent. Together, this undermines accurate article identification. The present study aims to develop and validate a search strategy to identify dental survival analyses indexed in MEDLINE (Ovid). MATERIALS AND METHODS: A gold standard cohort of articles was identified to derive the search terms, and an independent gold standard cohort of articles was identified to test and validate the proposed search strategies. The first cohort included all 6,955 articles published in the 50 dental journals with the highest impact factors in 2008, of which 95 articles were dental survival articles. The second cohort included all 6,514 articles published in the 50 dental journals with the highest impact factors for 2012, of which 148 were dental survival articles. Each cohort was identified by a systematic hand search. Performance parameters of sensitivity, precision, and number needed to read (NNR) for the search strategies were calculated. RESULTS: Sensitive, precise, and optimized search strategies were developed and validated. The performances of the search strategy maximizing sensitivity were 92% sensitivity, 14% precision, and 7.11 NNR; the performances of the strategy maximizing precision were 93% precision, 10% sensitivity, and 1.07 NNR; and the performances of the strategy optimizing the balance between sensitivity and precision were 83% sensitivity, 24% precision, and 4.13 NNR. The methods used to identify search terms were objective, not subjective. The search strategies were validated in an independent group of articles that included different journals and different publication years. CONCLUSIONS: Across the three search strategies, dental survival articles can be identified with sensitivity up to 92%, precision up to 93%, and NNR of less than two articles to identify relevant records. This research has highlighted the impact that variation in reporting and indexing has on article identification and has improved researchers' ability to identify dental survival articles.

Research Waste: How Are Dental Survival Articles Indexed and Reported?

PURPOSE: Research waste occurs when research is ignored, cannot be found, cannot be used, or is unintentionally repeated. This article aims to investigate how dental survival analyses were indexed and reported, and to discuss whether errors in indexing and writing articles are affecting identification and use of survival articles, contributing to research waste. MATERIALS AND METHODS: Articles reporting survival of dental prostheses in humans (also known as time-to-event) were identified by searching 50 dental journals that had the highest Impact Factor in 2008. These journals were hand searched twice (Kappa 0.92), and the articles were assessed by two independent reviewers (Kappa 0.86) to identify dental survival articles ("case" articles, n = 95), likely false positives (active controls, n = 91), and all other true negative articles (passive controls, n = 6,769). This means that the study used a case:control method. Once identified, the different groups of articles were assessed and compared. Allocation of medical subject headings (MeSH) by MEDLINE indexers that related to survival was sought, use of words by authors in the abstract and title that related to survival was identified, and use of words and figures by authors that related to survival in the articles themselves was also sought. Differences were assessed with chi-square and Fisher's Exact statistics. Reporting quality was also assessed. The results were reviewed to discuss their potential impact on research waste. RESULTS: Allocation of survival-related MeSH index terms across the three article groups was inconsistent and inaccurate. Statistical MeSH had not been allocated to 30% of the dental survival "case" articles and had been incorrectly allocated to 15% of active controls. Additionally, information reported by authors in titles and abstracts varied, with only two-thirds of survival "case" articles mentioning survival "statistics" in the abstract. In the articles themselves, time-to-event statistical methods, survival curves, and life tables were poorly reported or constructed. Overall, the low quality of indexing by indexers and reporting by authors means that these articles will not be readily identifiable through electronic searches, and, even if they are found, the poor reporting quality makes it unnecessarily difficult for readers to understand and use them. CONCLUSION: There are substantial problems with the reporting of time-to-event analyses in the dental literature. These problems will adversely impact how these articles can be found and used, thereby contributing to research waste. Changes are needed in the way that authors report these studies and the way indexers classify them.

Lost in translation: Review of identification bias, translation bias and research waste in dentistry.

OBJECTIVE: To review how articles are retrieved from bibliographic databases, what article identification and translation problems have affected research, and how these problems can contribute to research waste and affect clinical practice. METHODS: This literature review sought and appraised articles regarding identification- and translation-bias in the medical and dental literature, which limit the ability of users to find research articles and to use these in practice. RESULTS: Articles can be retrieved from bibliographic databases by performing a word or index-term (for example, MeSH for MEDLINE) search. Identification of articles is challenging when it is not clear which words are most relevant, and which terms have been allocated to indexing fields. Poor reporting quality of abstracts and articles has been reported across the medical literature at large. Specifically in dentistry, research regarding time-to-event survival analyses found the allocation of MeSH terms to be inconsistent and inaccurate, important words were omitted from abstracts by authors, and the quality of reporting in the body of articles was generally poor. These shortcomings mean that articles will be difficult to identify, and difficult to understand if found. Use of specialized electronic search strategies can decrease identification bias, and use of tailored reporting guidelines can decrease translation bias. Research that cannot be found, or cannot be used results in research waste, and undermines clinical practice. SIGNIFICANCE: Identification- and translation-bias have been shown to affect time-to-event dental articles, are likely affect other fields of research, and are largely unrecognized by authors and evidence seekers alike. By understanding that the problems exist, solutions can be sought to improve identification and translation of our research.

Will your article be found? Authors choose a confusing variety of words to describe dental survival analyses.

OBJECTIVES: Identify the words and phrases that authors used to describe time-to-event outcomes of dental treatments in patients. MATERIALS AND METHODS: A systematic handsearch of 50 dental journals with the highest Citation Index for 2008 identified articles reporting dental treatment with time-to-event statistics (included "case" articles, n = 95), without time-to-event statistics (active "control" articles, n = 91), and all other articles (passive "control" articles n = 6796). The included and active controls were read, identifying 43 English words across the title, aim and abstract, indicating that outcomes were studied over time. Once identified, these words were sought within the 6796 passive controls. Words were divided into six groups. Differences in use of words were analyzed with Pearson's chi-square across these six groups, and the three locations (title, aim, and abstract). RESULTS: In the abstracts, included articles used group 1 (statistical technique) and group 2 (statistical terms) more frequently than the active and passive controls (group 1: 35%, 2%, 0.37%, P < 0.001 and group 2: 31%, 1%, 0.06%, P < 0.001). The included and active controls used group 3 (quasi-statistical) equally, but significantly more often than the passive controls (82%, 78%, 3.21%, P < 0.001). In the aims, use of target words was similar for included and active controls, but less frequent for groups 1-4 in the passive controls (P < 0.001). In the title, group 2 (statistical techniques) and groups 3-5 (outcomes) were similar for included and active controls, but groups 2 and 3 were less frequent in the passive controls (P < 0.001). Significantly more included articles used group 6 words (stating the study duration) (54%, 30%, P = 0.001). CONCLUSION: All included articles used time-to-event analyses, but two-thirds did not include words to highlight this in the abstract. There is great variation in the words authors used to describe dental time-to-event outcomes. Electronic identification of such articles would be inconsistent, with low sensitivity and specificity. Authors should improve the reporting quality. Journals should allow sufficient space in abstracts to summarize research, and not impose unrealistic word limits. Readers should be mindful of these problems when searching for relevant articles. Additional research is required in this field.

Accuracy of medical subject heading indexing of dental survival analyses.

PURPOSE: To assess the Medical Subject Headings (MeSH) indexing of articles that employed time-to-event analyses to report outcomes of dental treatment in patients. MATERIALS AND METHODS: Articles published in 2008 in 50 dental journals with the highest impact factors were hand searched to identify articles reporting dental treatment outcomes over time in human subjects with time-to-event statistics (included, n = 95), without time-to-event statistics (active controls, n = 91), and all other articles (passive controls, n = 6,769). The search was systematic (kappa 0.92 for screening, 0.86 for eligibility). Outcome-, statistic- and time-related MeSH were identified, and differences in allocation between groups were analyzed with chi-square and Fischer exact statistics. RESULTS: The most frequently allocated MeSH for included and active control articles were "dental restoration failure" (77% and 52%, respectively) and "treatment outcome" (54% and 48%, respectively). Outcome MeSH was similar between these groups (86% and 77%, respectively) and significantly greater than passive controls (10%, P < .001). Significantly more statistical MeSH were allocated to the included articles than to the active or passive controls (67%, 15%, and 1%, respectively, P < .001). Sixty-nine included articles specifically used Kaplan-Meier or life table analyses, but only 42% (n = 29) were indexed as such. Significantly more time-related MeSH were allocated to the included than the active controls (92% and 79%, respectively, P = .02), or to the passive controls (22%, P < .001). CONCLUSIONS: MeSH allocation within MEDLINE to time-to-event dental articles was inaccurate and inconsistent. Statistical MeSH were omitted from 30% of the included articles and incorrectly allocated to 15% of active controls. Such errors adversely impact search accuracy.

Understanding Kaplan-Meier and survival statistics.

PURPOSE: This paper aims to explore the mathematics of Kaplan-Meier and survival statistics, explain how the mathematics are relevant for prosthodontic treatment planning, and provide advice for future presentation of such data. MATERIALS AND METHODS: The mathematics of the Kaplan-Meier and related survival statistic formulas were explored with hypothetical data consisting of 100 prostheses, reviewed yearly for 10 years. The hypothetical impact of failures (n = 1, 2, 9, or 0) and censored data (n = 5, 9, or 10) were reviewed across three life tables and survival curves. Actual published data of 304 porcelain veneers, reviewed regularly for 16 years, were similarly utilized. The impact of changing the number of failures and censored data on the estimated cumulative survival (ECS) and the standard error (SE) was reviewed across two life tables and survival curves. RESULTS: The ECS and SE are calculated from two data figures: the number of failures that occurred during an interval and the number of prostheses at risk during that same interval. The ECS reduces and its SE enlarges when prostheses fail. These results can also change if prostheses are lost from the study (censored). However, the number of failures is in the numerator of the equation. Therefore, if no failures occur, loss of prostheses from the study cannot change the ECS or the SE. This can dramatically affect the calculated ECS and SE if a prosthesis becomes lost to follow-up rather than presenting as a failure. The hypothetical and actual data were used to explore these concepts. CONCLUSION: Current techniques for analysis of time-to-event data are imperfect and can be misleading. It therefore behooves authors to strive to improve reporting transparency, journals to support such industry, and readers to remain mindful that the cumulative survival is an estimate, ie, a reflection of reality.

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

PURPOSE: This systematic review aimed to report and explore the survival of dental veneers constructed from non-feldspathic porcelain over 5 and 10 years. MATERIALS AND METHODS: A total of 4,294 articles were identified through a systematic search involving all databases in the Cochrane Library, MEDLINE (OVID), EMBASE, Web of Knowledge, specific journals (hand-search), conference proceedings, clinical trials registers, and collegiate contacts. Articles, abstracts, and gray literature were sought by two independent researchers. There were no language limitations. One hundred sixteen studies were identified for full-text assessment, with 10 included in the analysis (5 qualitative, 5 quantitative). Study characteristics and survival (Kaplan-Meier estimated cumulative survival and 95% confidence interval [CI]) were extracted or recalculated. A failed veneer was one which required an intervention that disrupted the original marginal integrity, had been partially or completely lost, or had lost retention more than twice. A meta-analysis and sensitivity analysis of Empress veneers was completed, with an assessment of statistical heterogeneity and publication bias. Clinical heterogeneity was explored for results of all veneering materials from included studies. RESULTS: Within the 10 studies, veneers were fabricated with IPS Empress, IPS Empress 2, Cerinate, and Cerec computer-aided design/computer-assisted manufacture (CAD/CAM) materials VITA Mark I, VITA Mark II, Ivoclar ProCad. The meta-analysis showed the pooled estimate for Empress veneers to be 92.4% (95% CI: 89.8% to 95.0%) for 5-year survival and 66% to 94% (95% CI: 55% to 99%) for 10 years. Data regarding other non-feldspathic porcelain materials were lacking, with only a single study each reporting outcomes for Empress 2, Cerinate, and various Cerec porcelains over 5 years. The sensitivity analysis showed data from one study had an influencing and stabilizing effect on the 5-year pooled estimate. CONCLUSION: The long-term outcome (> 5 years) of non-feldspathic porcelain veneers is sparsely reported in the literature. This systematic review indicates that the 5-year cumulative estimated survival for etchable non-feldspathic porcelain veneers is over 90%. Outcomes may prove clinically acceptable with time, but evidence remains lacking and the use of these materials for veneers remains experimental.

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%.