Comparative evaluation of the effect of different restorative materials and different loading times on the bond strength of the restoration in demineralized dentin treated with silver diamine fluoride; an In-Vitro study

Dental caries is recognized as one of the most common childhood diseases and Silver Diamine Fluoride (SDF) is increasingly utilized due to its effectiveness in arresting caries lesions. This thesis aims to comparatively evaluate the bond strengths between demineralized dentin and restorative material in extracted primary teeth restored with resin modified glass ionomer cement (RMCIS) and self-adhesive restorative material (SDR) immediately and two weeks after SDF application. The study was conducted by comparatively evaluating the bond strengths between the restorative material and the carious dentin restored with RMCIS and SDR immediately and two weeks after SDF application of artificially decayed primary molar teeth obtained from patients who applied to the Department of Pedodontics, Faculty of Dentistry, Karadeniz Technical University for tooth extraction. 68 extracted caries-free primary teeth were sectioned to obtain a flat dentin surface parallel to the occlusal plane and artificial caries was created with demineralization solution. The demineralized specimens were divided into four groups: Group 1; Restored with RMCIS (Fuji II LC Capsule, GC Corporation, Tokyo, Japan) immediately after the application of SDF, Group 2; Restored with SDR (SDR Plus Bulk Fill Flowable, Dentsply Sirona, Konstanz, Germany) immediately after the application of SDF, Group 3; Restored with RMCIS two weeks after the application of SDF, Group 4; Restored with SDR two weeks after the application of SDF using plastic molds measuring 3 mm × 4 mm. The groups scheduled to receive restorative material two weeks after the SDF application were stored in artificial saliva at 37°C in an incubator until restoration. All specimens with applied restorative materials were placed in containers filled with distilled water and subjected to an aging process in an incubator at 37°C for 30 days. After the aging process, all specimens were placed in Instron Universal testing machine and subjected to shear bond strength (MBS) test and the values obtained were converted to Megapascal (MPa) values and recorded. Fracture types were examined with a stereomicroscope at ×40 magnification and fracture surfaces were evaluated. Scanning electron microscopy (SEM) examination was performed on 2 specimens from each group. Shear bond strength test results and fracture surfaces were analyzed in detail. Descriptive statistics were given as mean, standard deviation, median, minimum and maximum values. Kruskal Wallis, Mann Whintey U test and Bonferroni correction were used for comparisons between groups. P<0.05 was considered statistically significant and the critical p value was recalculated when necessary. When the Shear Bond Strength test results were evaluated, statistically significantly higher bond strength values were obtained in RMCIS and SDR groups restored two weeks after SDF application compared to those restored immediately (p=0.009, p=0.011). When the bond strength values of the RMCIS group were compared with the SDR group, regardless of the timing of restoration after SDF application, the bond strength values of the SDR group were found to be higher, but this difference was not statistically significant (p>0.05). Based on the results of the study, it was seen that the restorations made two weeks after SDF application had a positive effect on the bond strength to carious dentin. Keywords: Silver Diamine Fluoride, Artificial Caries, Shear Bond Strength, SEM