Evaluation of the effects of a newly developed laser system (ER,CR:YSGG) on fissure sealants applied on primary teeth in vitro

The aim of this in vitro study was to evaluate the marginal integrity (microleakage and marginal gap) properties and microtensile values of fissure sealants applied to Er,Cr:YSGG laser etched primary teeth by comparing with conventional acid etching techniqueExtracted sound primary molar teeth were randomly assigned to one of five study groups including (1) 37% orthophosphoric acid, (2) 2.5 W laser, (3) 3.5 W laser, (4) 2.5 W laser + 37% orthophosphoric acid and (5) 3.5W laser + 37% orthophosphoric acid. For the evaluation of marginal integrity, a conventional sealant material (ClinPro Sealant) was applied to the fissures whereas the same material was applied to the buccal surfaces of primary molar teeth for microtensile testing. Prior to marginal integrity evaluation, sample teeth were subjected to thermocycling and then immersed to 0.5% basic fuchsin solution for 24 hours. After sectioning, 3 slices of each sample teeth were scored under stereomicroscope in terms of microleakage and marginal gap. For microtensile testing, mean bond strength values of the sectioned teeth were calculated and failure types were evaluated under stereomicroscope in additon to taking representative micrographs with scanning electron microscope (SEMWith respect to microleakage, a statistically significant difference was found between acid group and 2.5 W and 3.5 W groups (p<0.05), whereas no significant difference was detected between acid group and 2.5 W + acid and 3.5 W + acid groups (p>0.05). In terms of marginal gap formation, no significant difference was observed between groups (p>0.05). The results of microtensile testing revealed that acid group was significantly different than 2.5 W group (p<0.05) and no significant difference was found between acid and the other study groups (p>0.05). 2.5 W group was found significantly different than all study groups (p<0.05). No significant difference was detected between 3.5 W, 2.5 W + acid and 3.5 W + acid groups (p>0.05).In conclusion, etching with the combination of Er,Cr:YSGG laser system with acid was found as effective as conventional acid etching. Although 3,5 W Er,Cr:YSGG laser etching was not found as successful as acid etching in terms of microleakage, it may be used for enamel etching considering that no difference was observed with acid with respect to marginal gap formation and microtensile bond strength values.