Purpose: Laser pretreatment of dental hard tissues prior to preventive or restorative procedures has been a subject of research. Unground primary enamel bears a prismless superficial layer which is known to be acid resistant. This in vitro study was conducted in order to evaluate the potential use of Er,Cr:YSGG laser in the pretreatment of occlusal surfaces of primary teeth prior to bonded fissure sealant application.

Materials and methods: Occlusal surfaces of human primary mandibular molars were used (n =140). After pretreatment with Er,Cr:YSGG laser (group A) or not (group B), occlusal fissures were treated with one of the following in each of 7 subgroups (n = 10): 1. phosphoric acid-etch only; 2. Clearfil SE Bond; 3. FL Bond; 4. Adper Prompt L-Pop; 5. NRC+Prime & Bond NT; 6. One-Up Bond F; 7. Xeno III. All teeth were sealed with Fissurit F. The specimens were thermocycled (1000 times) and stored thereafter in distilled water at 37 degrees C for 8 months. Following immersion in 0.5% basic fuchsin solution, three bucco-lingual sections were made from each tooth. They were digitally photographed and the extent of dye penetration along the enamel-sealant interface was measured (in mm) with image analysis software.

Results: There was no difference between the Er,Cr:YSGG laser pretreated group (group A) and the nonlased grou (group B) (p > 0.05). The lowest microleakage values were observed in subgroups A1 and B1. Within the laser pretreated group, subgroups A1, A4, and A5 showed lower microleakage scores when compared to subgroups A2, A3, A6, and A7 (p < 0.05). As for the nonlased group, subgroups B1, B3, B4, and B5 demonstrated significantly lower microleakage scores than subgroups B2, B6, and B7 (p < 0.05).

Conclusion: Er,Cr:YSGG laser pretreatment was not found to influence the resistance to microleakage of bonded fissure sealant application in primary teeth.