A deep learning approach to dental restoration classification from bitewing and periapical radiographs.

OBJECTIVE: The aim of this study was to examine the success of deep learning-based convolutional neural networks (CNN) in the detection and differentiation of amalgam, composite resin, and metal-ceramic restorations from bitewing and periapical radiographs. METHOD AND MATERIALS: Five hundred and fifty bitewing and periapical radiographs were used. Eighty percent of the images were used for training, and 20% were left for testing. Twenty percent of the images allocated for training were then used for validation during learning. The image classification model was based on the application of CNN. The model used Resnet34 architecture, which is pre-trained on the ImageNet dataset. Average sensitivity, receiver operating characteristic (ROC) curve, and area under the curve (AUC) were calculated for performance evaluation of the model. RESULTS: The model training loss was 0.13, and the validation loss was 0.63. The independent test group result was 0.67. Amalgam AUC was 0.95, composite AUC was 0.95, and metal-ceramic AUC was 1.00. The average AUC was 0.97. The false positive rate in the validation set was 18, the false negative rate was 18, the true positive rate was 60, and the true negative rate was 138. The true positive rate was 0.82 for amalgam, 0.75 for composite, and 0.73 for metal-ceramic. CONCLUSION: Deep learning-based CNNs from periapical and bitewing radiographs appear to be a promising technique for the detection and differentiation of restorations.

Efficacy of different endodontic irrigation protocols on shear bond strength to coronal dentin.

AIM: The purpose of this study was to evaluate the effect of etidronic acid on bond strength to coronal dentin. MATERIALS AND METHODS: A total of 75 human mandibular molars were sectioned 3 mm below the occlusal surface and then randomly divided into five groups according to irrigation solution used (n = 15): Group 1: 5 ml 2.5% sodium hypochlorite (NaOCl) +5 ml distilled water; Group 2: 5 ml 2.5% NaOCl + 5 ml 17% ethylenediaminetetraacetic acid (EDTA); Group 3: 10 ml mixture of 5% NaOCl and 18% 1-hydroxyethylidene-1,1-bisphosphonate (HEBP); Group 4: 5 ml mixture of 5% NaOCl and 18% HEBP + 5 ml 17% EDTA; and Group 5: 5 ml mixture of 5% NaOCl and 18% HEBP + 5 ml distilled water. Thereafter, Clearfil SE bond was applied to the dentin surfaces and then, composite build-ups were created using Tygon tubes for the microshear bond strength test. Data were analyzed using the one-way analysis of variance and Tukey test. RESULTS: When compared to Groups 3, 4, and 5, Groups 1 and 2 showed significantly higher bond strength values (P < 0.05). However, there was no statistically significant difference between Groups 1 and 2 and between Groups 3, 4, and 5 (P > 0.05). CONCLUSION: HEBP adversely affected the bond strength of the tested adhesive to coronal dentin.

The effect of five different universal adhesives on the clinical success of class I restorations: 24-month clinical follow-up.

OBJECTIVES: The aim of this study was to evaluate the 24-month clinical performance of universal adhesives on the restoration success of Class I carious lesions. MATERIALS AND METHODS: Five different universal adhesives (Gluma Bond Universal (GU), Clearfil Universal (CU), Prime&Bond Elect Universal (PU), All bond Universal (AU), and Single Bond Universal (SU)) were used in the self-etch and etch-and-rinse modes in 42 patients. The study was conducted with 10 groups, with 20 restorations in each group. The restorations were evaluated at baseline and during a 24-month recall using World Dental Federation (FDI) and the US Public Health Service (USPHS) criteria. The changes in the parameters were analyzed using the chi-square test. RESULTS: At the end of 24 months, there was no loss of restoration in any group. According to the USPHS, there was no difference in the baseline and 24-month clinical behavior of the restorations (P Ëƒ 0.05). However, according to the FDI, when adhesives were used in the self-etch mode, three adhesives (GU, SU, PU) showed marginal incompatibility, and one adhesive showed (GU) marginal discoloration between baseline and the 24-month follow-up evaluation (P < 0.05). There was no significant difference after 24 months between etch-and-rinse and self-etch groups according to the results based on both the USPHS and FDI criteria (P Ëƒ 0.05). CONCLUSIONS: The 24-month clinical performance of the evaluated universal adhesives depends on the adhesive strategy. CLINICAL RELEVANCE: This study helps clinicians to decide in which mode (etch-and-rinse or self-etch) universal adhesives can be safely used.

Bonding performance of universal adhesives on composite repairs, with or without silane application.

AIM: This study aims to investigate the adhesive performance of three different universal adhesives to repair aged composite restorations, with or without the application of silane. MATERIALS AND METHODS: A hundred and twenty resin composite samples were prepared, aged and randomly divided into 6 main Groups (single bond universal [SBU], All-Bond Universal [ABU], Futurabond U, Clearfil Tri-S Bond, Single Bond 2, and Clearfil SE Bond) and 2 subgroups (with or without silane). A microhybrid composite resin was placed on the aged composite surfaces and light cured. After a micro-shear bonding test, the fracture surfaces were examined under the scanning electron microscopy. Statistical analysis was performed using two-way ANOVA and Tukey's post hoc tests. RESULTS: Among all the universal adhesives, SBU showed the highest bond strength values compared to the other two universal adhesives when used with and without silane (P > 0.05). Between ABU and Futurabond U, no significant difference was observed with silane (P > 0.05) and without silane (P > 0.05). Among conventional adhesives, there was no statistically significant difference (P > 0.05) both with and without silane. CONCLUSION: Within the limitations of this study, while SBU can be safely used with and without the application of silane, Futurabond U cannot be used without silane.

Micro-shear bond strength of universal adhesives used for amalgam repair with or without Alloy Primer.

AIM: The aim of this study was to investigate the adhesive performance of three different universal adhesives to repair aged amalgam by composite resins with or without Alloy Primer. MATERIALS AND METHODS: Sixty amalgam samples were prepared, aged, and randomly divided into 12 main groups according to adhesive procedures used. Composite buildups were placed on amalgam surfaces. After micro-shear bonding test, the fracture surfaces were examined under the scanning electron microscopy statistical analysis was performed using two-way analysis of variance and Tukey's post hoc tests. RESULTS: Without use of Alloy Primer, all of the universal adhesives provided similar bond strength values with conventional adhesives (P > 0.05); however, an Alloy Primer significantly increased the bond strength values of universal adhesives (P < 0.05). No significant difference in bond strength values was noted for conventional adhesives with or without Alloy Primer (P > 0.05) except for Clearfil SE Bond (P < 0.05). CONCLUSIONS: Within the limitations of this study, it can be concluded; using Alloy Primer before universal adhesives increased the bond strength significantly.