Effect of Different Disinfection Protocols on The Resin Bond Strength to Dentin: In Vitro Study.

Abstract Antimicrobial photodynamic therapy (aPDT) can be adopted as a modality for bacterial decontamination before cavity restoration to decrease the risk of secondary caries development. Trials to eliminate the microbial load using cavity disinfectants with no adverse effect on the bond strength of adhesive restoration geared toward the long-term success. C-phycocyanin is a safe photosensitizer to be used in disinfecting cavities before restoration especially in esthetic zone as it does not stain the tooth or the restoration as does the toluidine blue. (16) However no studies had evaluated the bond strength of resin to dentin disinfected with C-phycocyanin extracted from spirulina platensis. The teeth (n=48) will be allocated into 2 groups (n=24) according to the type of exposed dentin surface (coronal dentin and radicular dentin). Artificial caries affected dentin of coronal dentin (ACAD) will be induced after pH cycling for 14 days. Dentin surfaces will be disinfected either by using C-phycocyanin as photosensitizer activated using 635-nm diode laser or 2 % chlorohexidine or not disinfected (control group). Then one step self-etch adhesive will be bonded to coronal dentin followed by resin composite packing into the tygon tube applied perpendicular onto the coronal dentin.Self-adhesive resin cement will be bonded to radicular dentin by packing it into the tygon tubes applied perpendicular onto the radicular dentin. Microshear bond strength of self-etch adhesive to coronal dentin; and resin cement to radicular dentin will be tested. One sample from each group will be prepared for scanning electron microscope (SEM) examination.