Effect of antimicrobial photodynamic therapy on microleakage of class cavities restored with composite resin

Disinfection of enamel and dentin following cavity preparation is a necessity. Considering the possible effect of antimicrobial agents on tooth structure and dental adhesives, this study aimed to assess the microleakage of composite restorations following disinfection of cavity walls with antimicrobial photodynamic therapy (aPDT).

Standard class V cavities were prepared in the buccal surfaces of 68 extracted human premolars. The teeth were then randomly divided into four groups (n = 17) for use of different adhesive systems (Adper Single Bond 2 or One-Step Plus) and disinfection with aPDT. The cavities were filled with Filtek Ultimate composite. After thermocycling and immersion in 0.5% fuchsine, the teeth were sectioned and evaluated under a stereomicroscope to determine the microleakage score. Data were analyzed using the Kruskal Wallis and Wilcoxon tests (P < 0.05).

No significant difference was noted in microleakage in the occlusal and gingival walls among the study groups (P > 0.05). In each study group, microleakage in the gingival wall was significantly higher than that in the occlusal wall (P < 0.05).

Methylene blue-mediated aPDT does not seem to contribute to the microleakage of class V resin-based dental restorations, independently of the composition of bonding agents used.