Effect of individual or simultaneous curing on sealant bond strength.

PURPOSE

The objective of this study was to assess the shear bond strength of resin sealants to saliva-contaminated and noncontaminated enamel, comparing 2 curing protocols: (1) individual light-curing of the intermediate bonding agent layer and the sealant; or (2) simultaneous curing of both materials.

METHODS

Seventy-two enamel test surfaces were obtained from 24 third molars and randomly assigned to 2 groups (N=36): (A) saliva-contaminated; (B) noncontaminated. Each group was divided into 3 subgroups, according to the bonding technique: (1) Prime&Bond and Fluroshield were light cured separately; (2) Prime&Bond and Fluroshield were light cured together; (3) Fluroshield was applied alone. Shear bond strength was tested at a crosshead speed of 0.5 mm/minute.

RESULTS

Means (MPa) were: IA-15.61(+/-4.74); IIA-15.71(+/-6.18); IIIA-13.83(+/-1.50); IB-24.73(+/-4.34); IIB-22.41(+/-4.16); IIIB-18.20(+/-3.58). Statistical analysis revealed that overall bond strength to saliva-contaminated enamel was remarkably lower (P < .05) than that recorded under dry conditions. In both contaminated and noncontaminated groups, significantly higher shear bond strength (P < .05) was observed when the bonding agent was applied underneath the sealant. Comparing the curing protocols for contaminated specimens, no statistically significant difference (P > .05) was observed between individual and simultaneous curing. Conversely, for noncontaminated specimens, bond strength was higher and statistically different (P < .05) when the materials were light cured separately.

CONCLUSIONS

Individual or simultaneous curing of the intermediate bonding agent layer and the resin sealant does not seem to affect bond strength to saliva-contaminated enamel. When dry, noncontaminated conditions are maintained, however, the intermediary and the sealing materials should preferably be light cured separately.