Evaluation of a Technique for Reducing Chairside Occlusal Adjustment of Crowns.

PURPOSE: To assess whether the occlusion of metal-ceramic crowns, as received from the laboratory, and the time taken to adjust the occlusion of crowns not deemed acceptable, can be reduced by fabricating the crowns with controlled amounts of infra-occlusion during the laboratory phase. MATERIAL AND METHODS: An opposing set of typodonts, articulated in maximum intercuspal position served as the patient in an in vitro simulation. Seventy-five metal-ceramic crowns were fabricated for the mandibular right second molar with three different occlusal contact specifications: A, control group had occlusal contacts shared evenly by the crown and the neighboring teeth (n = 25); B, first experimental group had the occlusion relieved until 2 shimstock foils were able to be pulled from between the crown and the opposing tooth without tugging (n = 25); C, second experimental group had the occlusion relieved until 4 shimstock foils were able to be pulled from between the crown and the opposing tooth without tugging (n = 25). The occlusion of each crown, as received from the laboratory, was assessed using one of three categories (Excellent, Acceptable, and Poor). Chi-square analysis was used to test the differences in occlusal outcomes between the three study groups. For all of those rated "Acceptable," the time taken to adjust each crown to proper occlusion was recorded. One-way analysis of variance (ANOVA) and Bonferroni tests were carried out to compare the adjustment times across the three study groups. RESULTS: The 2-shim group had the best outcome, with 56% of the crowns rated as "Excellent" (p = 0.001). In addition, there were statistically significant differences in adjustment times between the control group (A) and the 2-shim (B) and the 4-shim (C) groups (p = 0.0001), but not between the 2-shim (B) and 4-shim (C) groups (p = 0.08). CONCLUSIONS: Metal-ceramic crowns fabricated with controlled interocclusal relief of 2- and 4-shims each required less time for chairside occlusal adjustment than crowns fabricated in the laboratory to conventional occlusal contact. However, the overall superior outcome, in terms of the possibility for immediate insertion as received from the laboratory as well as favorable chairside adjustment time, for the 2-shim prespacing suggests that this dimension is the preferred option over 4-shim prespacing to reduce occlusal inaccuracies of indirect restorations.

Reproducibility of subtraction radiography in monitoring changes in approximal carious lesions in children: An in vivo study.

BACKGROUND: Laboratory studies have shown that digital subtraction radiography (DSR) can be a more effective tool, than conventional radiography, in monitoring changes in carious lesions. The clinical performance of the technique, however, has not been sufficiently researched. AIM: To compare the reproducibility of DSR to that of bitewing radiographs, in monitoring changes in approximal caries in the mixed dentition. A secondary aim was to determine whether assessment outcomes differed as a function of the method used. DESIGN: Six assessors evaluated 310 lesions first on bitewings, then with DSR. The overall reproducibility was evaluated via intra-class correlation coefficient (ICC). Intra- and inter-rater reproducibility were assessed using weighted Kappa. Paired t test was used to assess differences in the reproducibility across methods. RESULTS: The overall reproducibility for DSR was (ICC = 0.47, 95% CI = 0.31-0.56). Intra- and inter-rater reproducibility were 0.65 and 0.44, respectively. The overall reproducibility for bitewings was ICC = 0.45, 95% CI = 0.42-0.57. Intra- and Inter-rater reproducibility were 0.71 and 0.46, respectively. Differences in the reproducibility across methods were not statistically significant. Significantly more lesions were scored as progressed using DSR. CONCLUSIONS: The reproducibility of DSR in monitoring changes in approximal caries is comparable to that of bitewings. Additionally, DSR detected higher proportion of progression than bitewing assessments.

The impact of ICDAS on occlusal caries treatment recommendations for high caries risk patients: an in vitro study.

BACKGROUND: The diagnostic criteria and tools used in caries lesion detection have been shown to affect the decision-making for caries treatment. Compared to other diagnostic criteria/classifications, ICDAS has been shown to provide a more accurate method for the detection of occlusal caries lesions. The influence of using ICDAS on caries treatment recommendations has received increasing attention in recent years. Therefore, the aim of this study was to assess the impact of ICDAS on dentists' occlusal caries lesions' treatment decisions for patients at high risk for caries. METHODS: Five dentists examined the occlusal surfaces of 270 extracted premolars and permanent molars. For a predetermined clinical scenario, the examiners were asked to indicate their treatment recommendations for each tooth. Four weeks later, all the examiners were trained and calibrated for the use of ICDAS. Then the investigators examined the same 270 teeth independently and indicated their treatment recommendations using the same clinical scenario. Histological validation was used to determine the caries lesions detection performance of the examiners using ICDAS and to assess the relationship between the presence of dentin caries and treatment recommendations for each examiner before and after ICDAS training. Specificity, sensitivity, area under the receiver operating characteristic curve (AUC), and Spearman's correlation coefficients were calculated. The Wilcoxon two-related sample rank test was used to test for differences between treatment recommendations. RESULTS: The strongest correlation for inter-examiner reproducibility was found between the ICDAS D2 cut-off point (ICDAS codes 3-6 as dentin caries) and histologic dentin caries. Treatment recommendations among different examiners before and after ICDAS training demonstrated a statistically significant increase in operative intervention and an increase in the percentage of overtreatment recommendations for two examiners. CONCLUSIONS: The impact of ICDAS on the examiners' caries lesion treatment recommendations varied among the dentists in this study. Treatment decision-making can be influenced by the caries lesion's detection and classification system used.

Variables affecting the inter- and intra-examiner reliability of ICDAS for occlusal caries diagnosis in permanent molars.

OBJECTIVES: The aims of this study were to assess the validity and reproducibility of the International Caries Detection and Assessment System (ICDAS) in detecting occlusal caries in permanent molars and to investigate variables that can affect the reproducibility of ICDAS. METHODS: Five experienced, trained, and calibrated investigators examined the occlusal surfaces of 142 extracted permanent molars, ranging from sound to cavitated dentine caries. All visual examinations were conducted under standard conditions. Examinations were repeated after a period of 1 and 3 months from the initial examination. After all examinations were completed, teeth were sectioned and histologic validation was undertaken. Maximum kappa statistics were used to assess bias among examiners and linear weighted kappa was used to assess inter- and intra-examiners' reproducibility. Sensitivity, specificity, accuracy and area under the receiver operating characteristic curve were obtained at D3 threshold. RESULTS: Differences in the marginal homogeneity were observed for the general dentist. Kappa for intra-examiner reproducibility ranged between 0.66 and 0.81 and the inter-examiner reproducibility ranged between 0.42 and 0.75. ICDAS score of ≥3 presented the best Spearman's correlation coefficient (0.69) at Downer's histologic classification D3. Corresponding sensitivity and specificity values at that level were 0.73 and 0.95, respectively. While variables like the interval of time between teeth examinations did not affect the intra-examiner reproducibility, examiners' specialty influenced inter-examiner's reproducibility over time. CONCLUSIONS: ICDAS presented acceptable intra-examiners reproducibility in detecting occlusal caries over time. However, there was a clear effect for examiner's specialty and clinical experience on the inter-examiner's reproducibility of the ICDAS system at different time intervals.

In vitro adhesion of oral Candida dubliniensis isolates to acrylic denture surfaces following brief exposure to sub-cidal concentrations of polyenes, azoles and chlorhexidine.

OBJECTIVES: We aimed to investigate the effect of brief exposure to sub-cidal concentrations of nystatin, amphotericin B, ketoconazole, fluconazole and chlorhexidine gluconate on the adhesion of oral Candida dubliniensis isolates to the surface of acrylic dentures. METHODS: After determining the minimum inhibitory concentration of each drug, 20 oral isolates of C. dubliniensis were exposed to sub-cidal concentrations of the drugs for 1 h. The drugs were then removed by dilution, and the adhesion of the isolates to denture acrylic strips was assessed by an in vitro adhesion assay. RESULTS: Compared to the controls, exposure to nystatin, amphotericin B, ketoconazole, fluconazole and chlorhexidine gluconate suppressed the ability of C. dubliniensis isolates to adhere to acrylic denture surfaces with a reduction of 74.68, 74.27, 57.31, 44.57 and 56.53% (p < 0.001 for all drugs), respectively. CONCLUSIONS: Brief exposure to sub-cidal concentrations of anti-mycotics suppressed the adhesion of C. dubliniensis oral isolates to acrylic denture surfaces.

A new approach to reliability assessment of dental caries examinations.

OBJECTIVES: The objective of this study is to evaluate reliability of the International Caries Detection and Assessment System (ICDAS) and identify sources of disagreement among eight Kuwaiti dentists with no prior knowledge of the system. METHODS: A 90-min introductory e-course was introduced followed by an examination of extracted teeth using the ICDAS coding system on the first day. Then three sessions of clinical examinations were performed. This study only used the data from the last session where 705 tooth surfaces of 10 patients were examined to assess bias in caries examination and on which codes the examiners had the highest disagreement. Compared with the gold standard, we evaluated bias of the ICDAS coding using three approaches (Bland-Altman plot, maximum kappa statistic, and Bhapkar's chi-square test). Linear weighted kappa statistics were computed to assess interexaminer reliability. RESULTS: Marginal ICDAS distributions for most examiners were significantly different from that of the gold standard (bias present). The primary source of these marginal differences was misclassifying sound surfaces as noncavitated lesions. Interexaminer reliability of the 3-level ICDAS (codes 0, 1-2, and 3-6) classification ranged between 0.43 and 0.73, indicating evidence of substantial inconsistency between examiners. The primary source of examiner differences was agreeing on diagnosing noncavitated lesions. CONCLUSION: This study highlights the importance of assessing both systematic and random sources of examiner agreement to correctly interpret kappa measures of reliability.