James D. Bader

Non-carious cervical lesions

Non-carious cervical lesions are commonly encountered in clinical practice and present in a variety of forms. A knowledge of the aetiology of these lesions is important for preventing further lesions, halting progression of lesions already present, and determining appropriate treatment. The most commonly cited aetiological factors thought to lead to the development of cervical lesions are erosion, abrasion and tooth flexure. Evidence supports a multifactorial aetiology for non-carious cervical lesions. The purpose of this paper is to review the evidence for each of these aetiological factors as it relates to the development of non-carious cervical lesions. Specific features of cervical lesions linked to these factors, including their morphology, location, prevalence and distribution by age and sex will be discussed. Suggestions for future research into the cause and prevention of non-carious cervical lesions will be presented.

The Effectiveness of Sealants in Managing Caries Lesions

A barrier to providing sealants is concern about inadvertently sealing over caries. This meta-analysis examined the effectiveness of sealants in preventing caries progression. We searched electronic databases for comparative studies examining caries progression in sealed permanent teeth. We used a random-effects model to estimate percentage reduction in the probability of caries progression in sealed vs. unsealed carious teeth. Six studies, including 4 randomized-controlled trials (RCT) judged to be of fair quality, were included in the analysis (384 persons, 840 teeth, and 1090 surfaces). The median annual percentage of non-cavitated lesions progressing was 2.6% for sealed and 12.6% for unsealed carious teeth. The summary prevented fraction for RCT was 71.3% (95%CI: 52.8%–82.5, no heterogeneity) up to 5 years after placement. Despite variation among studies in design and conduct, sensitivity analysis found the effect to be consistent in size and direction. Sealing non-cavitated caries in permanent teeth is effective in reducing caries progression.

Meta-analysis of fixed partial denture survival: Prostheses and abutments

STATEMENT OF PROBLEM Few estimates of the probability of various outcomes associated with replacement of missing teeth with fixed partial dentures have been reported. Existing longitudinal studies have reported widely disparate results for the survival of fixed partial dentures, but these studies have used different definitions of failure and varying periods of follow-up. PURPOSE This study used meta-analysis to formulate annual probability estimates for three categories of fixed partial denture or abutment survival. METHODS A systematic review of the English language literature since 1960 identified eight studies that met the preset inclusion criteria. Estimated annual survival proportions were back-calculated based on the Kaplan-Meier model and these proportions were combined through a fixed effects model meta-analysis. The probabilities and corresponding 95% confidence intervals at 5, 10, and 15 years for the three categories of survival are reported. RESULTS For the aggregate population represented by the limited longitudinal studies available, this meta-analysis indicated that less than 15% of fixed partial dentures were removed or in need of replacement at 10 years; whereas, nearly one third were removed or in need of replacement at 15 years. Less than 5% of abutments were removed at 10 years.

Effect of crown margins on periodontal conditions in regularly attending patients

Subgingival margins of cast restorations have been associated with increased gingival inflammation and probing depth, but it is not known if such effects would be seen among patients receiving regular professional care. In this study, 831 regularly attending patients in 35 North Carolina dental practices were examined. Plaque, gingival inflammation, calculus, and probing depth were assessed on facial and mesiofacial surfaces of the Ramfjord teeth. Surface-specific analyses showed significantly greater (p less than 0.05) gingival inflammation and deeper probing depths with subgingival cast restoration margins for nearly all surfaces examined. Less frequently, decreases in plaque and calculus were associated with the presence of crowns. Intact surfaces in patients with cast restorations were not significantly different from the same surfaces in patients without cast restorations. Even among patients receiving regular preventive dental care, subgingival margins are associated with unfavorable periodontal reactions.

Root caries risk indicators: a systematic review of risk models

OBJECTIVE To identify risk indicators that are associated with root caries incidence in published predictive risk models. METHODS Abstracts (n = 472) identified from a MEDLINE, EMBASE, and Cochrane registry search were screened independently by two investigators to exclude articles not in English (n = 39), published prior to 1970 (none), or containing no information on either root caries incidence, risk indicators, or risk models (n = 209). A full-article duplicate review of the remaining articles (n = 224) selected those reporting predictive risk models based on original/primary longitudinal root caries incidence studies. The quality of the included articles was assessed based both on selected criteria of methodological standards for observational studies and on the statistical quality of the modeling strategy. Data from these included studies were extracted and compiled into evidence tables, with information about the cohort location, incidence period, sample size, age of the study participants, risk indicators included in the model, root caries incidence, modeling strategy, significant risk indicators/predictors, and parameter estimates and statistical findings. RESULTS Thirteen articles were selected for data extraction. The overall quality of the included articles was poor to moderate. Root caries incidence ranged from 12% to 77% (mean ± SD = 45 ± 17%); follow-up time of the published studies was ≤ 10 years (range = 9; median = 3); sample size ranged from 23-723 (mean ± SD = 264 ± 203; median = 261); person-years ranged from 23 to 1540 (mean ± SD = 760 ± 556; median = 746). Variables most frequently tested and significantly associated with root caries incidence were (times tested; % significant; directionality): baseline root caries (12; 58%; positive); number of teeth (7; 71%; three times positive, twice negative), and plaque index (4; 100%; positive). Ninety-two other clinical and nonclinical variables were tested: 27 were tested three times or more and were significant between 9% and 100% of the times tested; and 65 were tested but never significant. CONCLUSIONS The root caries incidence indicators/predictors most frequently reported were root caries prevalence at baseline, number of teeth, and plaque index. This finding can guide targeted root caries prevention. There was substantial variation among published models of root caries risk in terms of variable selection, sample size, cohort location, assessment methods, incidence periods, association directionality, and analytical techniques. Future studies should emphasize variables frequently tested and often significant, and validate existing models in independent databases.

Incidence rates for complete cusp fracture

OBJECTIVES Although complete cusp fracture is acknowledged to occur frequently, incidence rates have been reported rarely. This study determined incidence rates for complete coronal cusp fracture per person and per tooth type. METHODS All fractures presenting among enrollees in a dental health maintenance organization using two geographically isolated clinics were noted for 105 days. For a sample of these enrollees, likelihood of attending the clinic in the event of a fracture was assessed through a telephone survey, and the at-risk status of all teeth was determined through a record survey. Incidence rates were calculated for persons, and for individual tooth types for all complete fractures and for non-carious complete fractures. In addition, for posterior teeth the distribution of fractured cusps, and the severity of fractures were examined. RESULTS Per-person incidence rates for complete coronal fractures for all teeth were 89.0 and 72.7 per 1000 person years, respectively, for all fractures and for non-carious fractures. The rates for all anterior and all posterior teeth were 10.2 and 69.9, respectively, for all non-carious fractures. In mandibular posterior teeth, lingual cusps fractured twice as frequently as facial cusps, while the opposite was true for maxillary premolars. Among maxillary molars, the mesiofacial and distolingual cusps fractured most frequently. The large majority of fractures exposed dentin (95%), while pulpal exposure occurred infrequently (3%). A minority of fractures extended below the gingival crest (24%) or the DEJ (25%). CONCLUSIONS This is the first report of fracture incidence rates for enumerated persons and teeth at risk and as such helps define the magnitude of the problem for dentists and their patients.

Clinical Decision Support Chairside Tools for Evidence-Based Dental Practice

Evidence-based clinical decision support (EB-CDS) tools designed for chairside use, help support the implementation of Evidence-Based Dentistry. EB-CDS tools organize available evidence and risk factors in order to facilitate clinical decision-making as well as to enhance rapid and effective transfer of knowledge to the patient at the point of care. Gingival recession, root exposure, caries, dental sealants, decay prevention and topical fluoride guides are presented and discussed. The Assess-Advise-Decide Approach, described in this article, better enables patients to determine which course of action is in line with their preferences and values.

Movement of Teeth Adjacent to Posterior Bounded Edentulous Spaces

Bounded edentulous spaces (BES)-a missing posterior tooth with intact adjacent teeth-are thought to lead to arch collapse resulting from the movement of adjacent teeth. To determine the rate of change in distance between teeth adjacent to a BES, we examined three successive measurable radiographs of 116 untreated posterior BES cases. The distance between the teeth (DBT) adjacent to the space was measured, and change in DBT (A DBT) between pre-extraction and follow-up radiographs was calculated. We used linear spline regression to construct models for tooth movement and to identify factors associated with A DBT. The mean A DBT was < 1 mm during the first year post-extraction, and the DBT continued to decrease at a successively slower rate each following year. Overall and for each tooth type, the greatest rates of decrease in DBT were seen in the zero to two-year period. In a multivariable model, time since extraction and tooth type were significantly associated with A DBT. These findings suggest that movement of teeth adjacent to a posterior BES after the first two years is usually gradual and minor within the time frame of this study.

Efficacy of Chlorhexidine Varnish for the Prevention of Adult Caries A Randomized Trial

The Prevention of Adult Caries Study, an NIDCR-funded multicenter, double-blind, randomized clinical trial, enrolled 983 adults (aged 18-80 yrs) at high risk for developing caries (20 or more intact teeth and 2 or more lesions at screening) to test the efficacy of a chlorhexidine diacetate 10% weight per volume (w/v) dental coating (CHX). We excluded participants for whom the study treatment was contraindicated or whose health might affect outcomes or ability to complete the study. Participants were randomly assigned to receive either the CHX coating (n = 490) or a placebo control (n = 493). Coatings were applied weekly for 4 weeks and a fifth time 6 months later. The primary outcome (total net D1-2FS increment) was the sum of weighted counts of changes in tooth surface status over 13 months. We observed no significant difference between the two treatment arms in either the intention-to-treat or per-protocol analyses. Analysis of 3 protocol-specified secondary outcomes produced similar findings. This trial failed to find that 10% (w/v) chlorhexidine diacetate coating was superior to placebo coating for the prevention of new caries (Clinicaltrials.gov registration number NCT00357877).

Methods dentists use to diagnose primary caries lesions prior to restorative treatment: Findings from The Dental PBRN

OBJECTIVE To (1) quantify the diagnostic techniques used by Dental Practice-Based Research Network (DPBRN) dentists before they decide to treat primary caries lesions surgically and (2) examine whether certain dentist, practice, and patient characteristics are associated with their use. METHODS A total of 228 DPBRN dentists recorded information on 5676 consecutive restorations inserted due to primary caries lesions on 3751 patients. Practitioner-investigators placed a mean of 24.9 (SD=12.4) restorations. Lesions were categorised as posterior proximal, anterior proximal, posterior occlusal, posterior smooth, or anterior smooth. Techniques used to diagnose the lesion were categorised as clinical assessment, radiographs, and/or optical. Statistical analysis utilised generalised mixed-model ANOVA to account for the hierarchical structure of the data. RESULTS By lesion category, the diagnostic technique combinations used most frequently were clinical assessment plus radiographs for posterior proximal (47%), clinical assessment for anterior proximal (51%), clinical assessment for posterior occlusal (46%), clinical assessment for posterior smooth (77%), and clinical assessment for anterior smooth (80%). Diagnostic technique was significantly associated with lesion category after adjusting for clustering in dentists (p<0.0001). CONCLUSION These results - obtained during actual clinical procedures rather than from questionnaire-based hypothetical scenarios - quantified the diagnostic techniques most commonly used during the actual delivery of routine restorative care. Diagnostic technique varied by lesion category and with certain practice and patient characteristics.