Effect of selected pulpotomy materials on the shear bond strength of a composite material to primary dentin using a universal adhesive

Relevance. During pulpotomy procedures in primary teeth, the contamination of cavity walls by the applied pulpotomy material is unavoidable and may compromise the adhesion of restorative materials. Notably, the use of rubber dam isolation does not eliminate the risk of dentin surface contamination within the area of endodontic access. Objective. To evaluate the effect of two pulpotomy materials—one containing MTA and the other a non-MTA-based formulation with moderate fixative action—on the shear bond strength (SBS) between a composite restorative material and primary dentin when a universal adhesive system is used. Materials and methods. This study evaluated a modern universal adhesive system (OptiBond Universal) in combination with its corresponding proprietary composite restorative material. Extracted first primary molars from 6- to 7-year-old children, removed for surgical indications, were used. Two types of pulpotomy materials were applied to the dentin surface of the specimens: an MTA-containing material (Group 1) and a non-MTA-based material with moderate fixative action (Group 2). Each material was applied for 60 seconds and then removed using a cotton roll. The SBS between the composite material and dentin was measured in accordance with GOST R 51202-98. Morphological evaluation of the specimens before and after testing was conducted using fluorescent microscopy at magnifications of ×30, ×250, and ×300. The Mann–Whitney U-test was used to assess the statistical significance of differences in SBS values between the two independent groups. Results. The SBS of the composite material to primary dentin using the universal adhesive in Groups 1 and 2 indicated that exposure to the MTA-containing material did not result in a statistically significant difference in mean SBS values compared to the control group. In contrast, exposure to the non-MTA-based pulpotomy material with moderate fixative action led to a 22% reduction in the mean SBS value relative to the control group.