The Influence Of The Etching Time On The Enamel Hybridization In Preventive Sealing. In Vitro Study

Adhesion of dental materials to the dental hard tissue is dependent on a number of factors relating both to the material used and the type of approach to dental substrate. The purpose of this study was to analyze the size of the hybrid layer (HL) in evaluated sealed oclussal surfaces by scanning electron microscopy (SEM). Method: The study was realized in vitro on a sample of 16 human teeth premolars and molars extracted for orthodontic or periodontal reasons. Permission was obtained from an institutional ethical committee of “Gr. T. Popa” University of Medicine and Pharmacy, Iasi and the subjects gave written, informed consent. The teeth were randomly divided into two equal groups (Gr1=etching time 20 seconds and GR2=etching time 60 seconds). The teeth were restored using 3M™ Schotchbond Etch, Single Bond Dental Adhesive System 3MTM, composite resin Concise (3MESPE). The materials were photo activated with halogen source (3M), stored (48h), cut lengthwise (diamond), polished, conditioned (H3PO4-37%-5s) analysed by SEM (TESLA, BS 340), SPSS14.00 statistically analysed (ANOVA, p≤0.05). Results: Analysis of the HL has highlighted differences between groups only in the enamel p=.000 average size HL being Gr.1:17.76 (±6.7)μm;Gr.2:6.36(±2.8)μm. Conclusions: The thickness of hybrid layer related directly proportional with etching time, after 60 second the hybrid layer had a thickness of about three times higher than in the case for 20 seconds demineralization. Key words: resin composite, hybrid layer, enamel etc