Analysis of the interfacial micromorphology of adhesive systems in cavities prepared with Er,Cr:YSGG, Er:YAG laser and bur

The purpose of this in vitro study was to evaluate the interaction pattern of adhesive systems on laser and bur cavities. Cavities were prepared according to the following groups (n=9): (G1) conventional diamond bur (No. 1013); (G2) Er:YAG laser (250 mJ, 4 Hz, 80.6 J/cm2); (G3) Er,Cr:YSGG laser (3.5 W, 20 Hz, 61.7 J/cm2). After cavity preparation, specimens were divided into three subgroups differing the adhesive systems used (n=3): (GA) AdheSE; (GB) Clearfil standard error (SE) Bond; (GC) Single Bond. After insertion of a micro-hybrid composite resin, the specimens were sectioned across the bonded surface dividing the teeth into two halves, which were prepared for SEM analysis. Cavities prepared with laser appeared to be more irregular than the bur cavities. Different patterns of gap formation and resin tags could be observed, showing the differences, advantages, and disadvantages of both types of cavities. Under the settings of the present study, resin tags were more pronounced in lased dentin than bur prepared dentin independently of the bonding systems used. On the other hand gap formation between dentin and resin in laser prepared cavities was observed suggesting collagen alteration.