Dental unit waterline antimicrobial agents' effect on dentin bond strength

Background. In response to concerns of bacterial bio film colonization of d ental unit waterlines, a wide range of commercial intermittent and continuo us chemical treatments for dental unit waterlines have been developed and m arketed. There has been little research on the possible effect of continuou s chemical treatment regimens on dentin-bonding agents. The authors evaluat e the effect of four proposed antimicrobial agents used in dental unit wate rlines on dentin bond strength. Methods. The authors used a fifth-generation dentin-bonding agent to bond c omposite cylinders to molar dentin surfaces. They then used selected antimi crobial agents as rinsing agents after conditioning. The composite cylinder s were shear tested, and their fracture strengths were compared statistical ly. Results. All proposed antimicrobial agents reduced dentin bond strength. Pr oposed waterline treatment regimens of a diluted mouthrinse and chlorhexidi ne significantly reduced dentin bond strength compared with sodium hypochlo rite and citric acid regimens. Conclusion. Dental professionals should be aware of potential interactions between dental unit waterline antimicrobial agents and dentin-bonding agent s. Further research in this area is warranted, as the clinical implications are uncertain at this time. Clinical Implications, Dental unit waterline antimicrobial agents may adver sely affect dentin bonding strength.