Influence of disinfectants on dentin bond strength of different adhesive systems

The influence of water disinfectants used in dental unit waterlines on the dentin bonding of different adhesive systems was investigated by using push-out tests. Three hundred and twenty dentin disc specimens were prepared from caries-free human molars. In each specimen, a standardized conical cavity was prepared while cooling with water from a dental unit containing one of three different disinfectants (n=80 each group; A=control: water without disinfectant, B: Alpron neutral, C: Alpron mint, D: Dentosept P). Subsequent rinsing of the cavities was performed With the respective disinfectant. The cavities were filled with the following combinations of dentin adhesives and composites, resulting in 16 subgroups (n=20): Syntac Classic/Tetric Ceram, Clearfil Liner Bond 2V/Luxacore, OptiBond FL/Prodigy and Prime&Bond NT/Spectrum. After polishing the fillings, one half of each subgroup (n=10) was stored in water (37 degrees C) for 24 hours. The other half was stored in water (37 degrees C) for 180 days and additionally thermocycled (2000 cycles at 5/55 degrees C). The bond strength was then measured by push-out tests. Statistical analysis of the data was carried out using ANOVA and pairwise t-tests (Significance level p < or = 0.01). The disinfectants showed no significant influence on the loads required for debonding of Syntac Classic/Tetric Ceram, Clearfil Liner Bond 2V/Luxacore and OptiBond FL/Prodigy as compared to the controls. However, the use of disinfectants in the water supply of a dental unit decreased dentin bond strength in the specimens filled with Prime&Bond NT/Spectrum. Disinfectants in the water of dental unit waterlines may have an influence on dentin bonding, depending on the adhesive system used.