Uloga svetlosno polimerizujućih i adhezivnih tehnika u proceni marginalne adaptacije kompozitnih smola za gleđ i dentin

Abstract

Introduction The quality of bond between composite and hard dental tissue is most commonly estimated on the basis of strength of bond or absence of marginal gap along restoration border. Marginal index (MI) is a significant indicator of the efficiency of the bond between material and dental tissue because it also shows the values of width and length of marginal gap. The aim of this paper was to estimate quantitative and qualitative features of the bond between composite resin and enamel and dentin, and to determine the values of MI in enamel after application of two techniques of photopolymerization of composite and two composite adhesive systems. Also, the impact of longevity of photopolimerization on genotoxicity of composite adhesives has been investigated. Material and methods Forty Class V cavities were prepared and restored for scanning electron microscope (SEM) analysis of composite bonding to enamel and dentin. Adhesion to enamel and dentin was secured by etch and rinse procedure (adhesive-Adper Single Bond 2-ASB/3M ESPE), i.e. by self etch primer/adhesive (Adper Easy One-AEO/3M ESPE). Photopolymerization of composite resin (Filtek Ultimate-3M ESPE) was performed using standard halogen light or gradually, using soft start program. Genotoxyciti of adhesives was invastigated using Comet assay. Results The smallest average MI was determined with gradual light curing and application of ASB/FU material. Qualitative analysis showed better marginal adaptation after application of etch and rinse adhesive technique and gradual light curing, compared to self etch adhesive technique and standard photoactivation. Dentin did not show significant differences in the bond between composite restorations and dentine tissue compared to light curing technique but significant difference were determined with respect to the type of adhesive composite material (adhesive technique). Dentin also 108 showed a better quality of the composite bond with etch and rinse adhesive technique, regardless of light curing technique. Using Comet assay it was concluded that significant lower genotoxicity showed both adhesives after photopolymerization in duration of 40 seconds compared to 10 seconds. Conclusion The best marginal adaptation of composite (lowest MI) to enamel and dentin was obtained with gradual soft start photoactivation in etch and rinse adhesive technique and ASB/ FU material. The best marginal adaptation of composite (lowest MI) for dentin was also determined with etch and rinse adhesive technique and the same material, regardless of photopolymerization technique. Longer duration (40 sek) of photoactivation of adhesives in regard to recommendations of manufactures (10 sek.) contributs to lowering of their genocitotoxicity.