Introducing a new auto edge detection technique capable of revealing cervical root resorption in CBCT scans with pronounced metallic artifacts.

Cervical resorption is a serious threat to the longevity of the teeth. In this study, the Canny edge-detection algorithm was applied on CBCT images to compare the accuracy of original and Canny views for diagnosing cervical resorption in endodontically treated teeth. Intracanal metallic posts were inserted in 60 extracted teeth being randomly divided into three groups: control, 0.5 mm, and 1 mm cervical resorption. CBCT scans of the teeth were presented to three observers in both original and Canny formats with the accuracy being determined by receiver operating characteristic (ROC) analysis. The DeLong test was used for paired comparisons with the significance level set at 0.05. The highest accuracy belonged to Canny images in 1 mm resorption, followed by Canny images in 0.5 mm resorption, original images in 1 mm resorption, and original images in 0.5 mm resorption, respectively. The Canny images were significantly more accurate in the diagnosis of 0.5 mm (p < 0.001) and 1 mm (p = 0.009) resorption. Application of the Canny edge-detection algorithm could be suggested as a new technique for facilitating the diagnosis of cervical resorption in teeth that are negatively affected by metallic artifacts.

Evaluation of 940-nm diode laser effectiveness on pocket depth, clinical attachment level, and bleeding on probing in chronic periodontitis: A randomized clinical single-masked split-mouth study.

Background: Diode lasers can be used in the treatment of periodontal diseases as they have an anti-bactericidal effect, and regulate oral tissue inflammatory responses. This study aimed to evaluate the adjunctive effects of Diode 940 nm laser on mechanical periodontal debridement. Materials and Methods: In this split-mouth single-blind randomized clinical trial, 12 patients were selected. Forty-four oral segments were enrolled in the scaling and root planing (SRP) group and SRP + Laser group with a 1:1 allocation ratio following a simple randomization procedure (coin flip). Clinical parameters (pocket depth, clinical attachment loss [CAL], and bleeding on probing [BOP]) were measured at baseline. After the SRP, a 940 nm Diode laser (1 Watt power and continuous wave mode) was used in the SRP + Laser group as an adjunctive treatment. The clinical parameters were remeasured 2 months posttreatment. Statistical analysis was carried out using an unpaired t-test with a 5% significant level by SPSS. Results: Although all clinical parameters had more improvements in the SRP + Laser group, the differences were not significant between the two study groups (P > 0.05). Only in individual tooth evaluations, CAL changes in first and second premolars and BOP changes in second premolars show statistically significant improvement in the SRP + L group compared to the SRP group (P < 0.05). Conclusion: Using diode 940 nm laser as an adjunctive treatment for SRP may be helpful and be suggested for periodontal treatment.

The effect of preheating of composite resin on its color stability after immersion in tea and coffee solutions: An in-vitro study.

BACKGROUND: One of the concerns in using composite resins is color change. The aim of this study was to investigate the effect of preheating on color stability of composite resins when immersed in coffee and tea. MATERIAL AND METHODS: This experimental study included 60 composite disks. The samples were divided into 2 groups, one group prepared at room temperature and the other prepared at 68 °C. After curing, the samples were placed in 37 °C distilled water for 24 hours. The color of the samples was measured (t0) using spectrophotometer according to CIE-L*a*b* system. The samples of each group were then divided into 3 subgroups and respectively immersed in distillated water, coffee and tea for 30 days and the final color (t1) was measured. The difference between the measured colors was calculated (∆E) and the results were analyzed using version 21.0 of SPSS software, Paired t-test, ANOVA, Tukey's test, and Dunnett t-test. RESULTS: The preheated composites showed significantly lower staining in the coffee solution than the room temperature composites (p<0.0001). In contrast, no statistically significant difference was observed for the tea solution (p =0.317). The staining of the preheated composites in distillated water was higher than those in the room temperature, however, the difference was not significant (p =0.99). CONCLUSIONS: Within the limits of this study, preheating was effective to improve color stability of composite resin after long time immersion in coffee solution. Key words:Composite resin, color stability, preheating.