Sealing Carious Fissures with Resin Infiltrant in Association with a Flowable Composite Reduces Immediate Microleakage?

Abstract Objective: To compare the immediate microleakage of carious fissures sealed with a caries infiltrant covered by a flowable composite or solely with a flowable composite. Material and Methods: Extracted carious molars (n=20) were selected and paired among the experimental groups according to caries progression scores. Experimental groups (n=10) were divided according to the following sealing techniques: 1) caries infiltrant (Icon) + flowable composite (Z350 flow); 2) flowable composite (Z350 flow). Specimens were immersed in 3% methylene blue and evaluated in a stereomicroscope. Microleakage scores were attributed independently by two calibrated evaluators and the mode value was considered as the mean for the specimen. Binomial tests were used to test differences between two independent sample proportions at 5% significance level. Results: In the flowable composite group, a higher prevalence of dye penetration along the full depth of the fissure was observed, compared with caries infiltrant + flowable composite (p<0.05). For specimens showing dye penetration up to half of the fissure, in caries infiltrant + flowable composite group, all specimens showed dye penetration into the sealant, but not over the infiltrant. Conclusion: Using caries infiltrant as sealing material under a flowable composite cover is effective to improve the immediate sealing ability in carious fissures compared to sealing with flowable composite.

Root canal segmentation in cone-beam computed tomography: comparison with a micro-CT gold standard

Aim: The purpose of this study was to compare root canal volumes (RCVs) obtained by means of cone beam computed tomography (CBCT) to those obtained by micro-computed tomography (micro-CT) after applying different segmentation algorithms. Methods: Eighteen extracted human teeth with sound root canals were individually scanned in CBCT and micro-CT using specific acquisition parameters. Two different images segmentation strategies were applied to both acquisition methods (a visual and an automatic threshold). From each segmented tooth, the root canal volume was obtained. A paired t-test was used to identify differences between mean values resulted from the experimental groups and the gold standard. In addition, Pearson correlation coefficients and the agreement among the experimental groups with the gold standard were also calculated. The significance level adopted was 5%. Results: No statistical differences between the segmentation methods (visual and automatic) were observed for micro-CT acquired images. However, significant differences for the two segmentation methods tested were seen when CBCT acquired images were compared with the micro-CT automatic segmentation methods used. In general, an overestimation of the values in the visual method were observed while an underestimation was observed with the automatic segmentation algorithm. Conclusion: Cone beam computed tomography images acquired with parameters used in the present study resulted in low agreement with root canal volumes obtained with a micro-CT tomography gold standard method of RCV calculation

Accuracy of visual and image-based ICDAS criteria compared with a micro-CT gold standard for caries detection on occlusal surfaces

Abstract The aim of this study was to check the in vitro accuracy of ICDAS criteria on digital images compared to visual examination for the diagnosis of occlusal caries against a micro-CT gold standard. ICDAS was scored in 40 extracted permanent molars by means of visual inspection and stereomicroscopic images. Visual examinations were performed in duplicate and at a one-week interval by three different calibrated examiners. The analysis of digital images by ICDAS criteria was also performed in duplicate, 1 month after visual examinations. The detection methods were compared by means of sensitivity, specificity, area under the curve, predictive positive and negative values, and accuracy for two different thresholds (1- sound vs. carious teeth; 2- tooth requiring operative vs. non-operative treatment). Sensitivity and accuracy values for threshold 1 in the visual ICDAS and image-based ICDAS methods were high for sensitivity (0.93 and 0.97) and for accuracy (0.83 and 0.85), but low for specificity (0.55 for both methods). Specificity values for threshold 2 were 0.77 and 0.82, while sensitivity was 0.33 and 0.28 for each method. Spearman's rank correlation coefficient was 0.53 and 0.43 (p<0.05) for visual and image-based ICDAS compared to the gold standard scores. Both visual and image-based ICDAS scores were similar to each other in terms of diagnostic accuracy when compared to the micro-CT gold standard. Low specificity for the presence of caries and sensitivity for the detection of caries requiring operative treatment were found.