Biocompatibility of universal dental adhesives: An in vitro study.

Statement of problem: Adhesives play an essential role in restorative dentistry, and Universal Bond Quick (UBQ) has been marketed as having a short application time and long-term resistance to hydrolysis. However, research on its biocompatibility is lacking.

Purpose: The purpose of this in vitro study was to compare the biocompatibility of 3 recently introduced universal dental adhesives: UBQ, Single Bond Universal (SBU), and Prime&Bond Universal (PBU), and the popular clinical dental adhesive SE Bond.

Material and methods: The CCK-8 assay, Calcein AM-PI, Real-time qPCR, DNA damage, and Cell cycle were used to evaluate the biocompatibility of each adhesive. Microleakage of the dental adhesives was also tested through immediate and chemical aging dye penetration in vitro experiments. An ANOVA, t test, Kruskal-Wallis, and Mann-Whitney tests were used for the statistical analyses (α=.05).

Results: The biocompatibility results showed that the inhibitory effect of UBQ and SBU on the proliferation of L929 cells was lower than that of PBU and SE. The proportion of viable cells in the SBU group decreased when the concentration reached 25%, while the proportion of viable cells in the UBQ group remained unchanged at this concentration. Concentrations of PBU and SE of 6.25% caused DNA damage in L929 cells. After chemical aging, the gingival microleakage of specimens in the UBQ and PBU groups was more obvious than that of occlusal microleakage, and the difference was statistically significant (P<.05).

Conclusions: The biocompatibility of UBQ and SBU was similar and better than that of PBU and SE. However, after aging, the microleakage of the UBQ and PBU was slightly poorer in the thin enamel area near the gingival margin.