DENTISTRY, vol.1, no.3, pp.1-5, 2011 (Refereed Journals of Other Institutions)
The aim of this study was to evaluate effect of different techniques of enamel etching on shear bond strengths (SBS) of fissure sealants. Fifty extracted non-carious third molars were cleaned with fluoride-free pumice and root sections 2mm below cementoenamel junction were taken. Coronal sections were embedded in resin, and buccal/ lingual surfaces of crowns were flattened to create an enamel surface area that was 3mm in diameter. The specimens were randomly assigned to 1 of 5 groups with 10 teeth each. Group1 35% orthophosphoric acid–etching (20sec); Group2 a fissurotomy–bur (Fissurotomy Micro–NTF); Group3 Erbium, Chromium:yttrium-scandium-galliumgarnet (Er,Cr:YSGG) laser 2W laser etching (20sec–20Hz); Group4 Er,Cr:YSGG laser 2W laser etching (20sec–40Hz); and Group5 20sec air-abrasion with 30μm Al2 O3 particles Cojet–Prep. Cylindrical-transparent-gelatin tubes (diameter:3mm–height:2mm) were placed on substrate surfaces. Further, sealants were applied and cylinders of fissure sealants were submitted to an SBS test in a universal testing machine with a crosshead speed of 0.5 mm per second. The data were analyzed by means of one-way analysis of variance and Tukey’s post-hoc tests (p<0.05). The SBS values (mean±SD–MPa) were obtained as Group1 (8.47±1.30)>Group4 (5.99±1.36)> Group3 (5.27±1.56)>Group5 (2.02±0.86)>Group2 (1.65±0.69). Group1 exhibited significantly higher SBS values compared to other groups. Group4 resulted in higher SBS values compared to Group3, although no significant differences were found. No significant differences were observed between Groups2 and 5. It can be concluded that, compared with conventional enamel acid–etching, laser 2W–20Hz/40Hz may have an advantage in improving SBS values of fissure sealants compared to Cojet–Prep and fissurotomy–bur techniques.