Influence of a MDPB-containing disinfectant on bonding of universal adhesives

Objectives: The experimental cavity disinfectant containing an antibacterial monomer MDPB (12-methacryloyloxydodecylpyridinium bromide) has been reported to have greater dentin permeability and be more effective in killing bacteria in the dentinal tubules than the commercially available chlorhexidine-containing disinfectant (Hirose et al., J Dent Res, 2016, IADR 96^th general session & Exhibition, 2018). In this study, influences of the MDPB-containing cavity disinfectant on dentin bonding ability of four different universal adhesives were evaluated.
Methods: The experimental cavity disinfectant (ACC) prepared by adding MDPB at 5% into 80% ethanol was used. Twelve non-carious human molars were randomly devided into four groups. The dentin surface was treated with ACC, and composites were bonded using four kinds of universal adhesives (Clearfil Universal Bond Quick, Kuraray Noritake Dental, UQ; Scotchbond Universal Adhesive, 3M ESPE, SU; BeautiBond Universal, Shofu, BU; Tokuyama Universal Bond, Tokuyama Dental, TU). After storage in water for 24 hours, the microtensile bond strength (MTBS) were measured. Failure modes were determined by microscopic observation. Additionally, adhesive interfaces were observed by scanning electronic microscopy (SEM). No treatment with any disinfectants served as the control.
Results: For all of UQ, SU, BU, and TU, MTBS for the experimental group treated with ACC demonstrated no significant difference between that for the control (Student’s t-test, p>0.05). Regardless of ACC application, the predominant mode was adhesive failure in all adhesives (UQ 86.7%, SU 86.7%, BU 80%, TU 93.3%). By SEM, no morphological difference was observed at the bonding interface of ACC-treated group and the control.
Conclusions: Application of the experimental cavity disinfectant containing MDPB was found to show no adverse influences on dentin bonding ability of four universal adhesives tested.