Influence of photo-curing distance on bond strength and nanoleakage of self-etching adhesive bonds to enamel and dentin.

Light activation of composites is more then turning on the curing light.  There are many factors that can influence the degree of curing both the bonding agent and composite. Good curing technique is very important for a better restoration. MJ

Acta Odontol Scand. 2014 Feb;72(2):113-9. doi: 10.3109/00016357.2013.805431. Epub 2013 Jul 3.

Abstract

Abstract Objectives. To assess the influence of light-curing unit tip distance on the microtensile bond strength (μTBS) and nanoleakage of self-etching adhesives to enamel and dentin. Materials and methods. Flat buccal surfaces were prepared on 198 bovine incisors. The teeth were randomly assigned into nine groups for μTBS (n = 8) and nanoleakage (n = 3) testing according to the adhesive system (Clearfil Protect Bond, Clearfil Tri-S Bond or One Up Bond F Plus) and distance from the light-curing tip (0, 3 or 6 mm). The bonded samples were tested in tension (0.5 mm/min) and nanoleakage was analyzed using SEM. Results. Clearfil Protect Bond exhibited the highest tensile strength on both enamel and dentin. Leakage was higher in samples exposed at a distance of 6 mm on enamel and 0 mm on dentin. One Up Bond F Plus experienced the greatest amount of nanoleakage on both substrates. Conclusions. Light-curing unit distance did not influence the μTBS of the adhesives, but nanoleakage increased on enamel samples when photoactivation occurred at a distance of 6 mm.