Microleakage of Four Different Restorative Glass Ionomer Formulations in Class V Cavities: Er:YAG Laser versus Conventional Preparation

Objective: To investigate microleakage in class V cavities following restoration with conventional glass-ionomer cements (CGICs) or resin-modified glass-ionomer cements (RMGICs), following Er:YAG laser or conventional preparation. Background Data: The sealing ability of GICs in Er:YAG-lased cavities has not been studied extensively. Methods: Three hundred and twenty class V cavities were assigned to four groups: those in groups A and B were prepared using an Er:YAG laser, and those in groups C and D were conventionally prepared. In groups B and D the surface was additionally conditioned with cavity conditioner. Each group was subdivided according to the GIC used: groups 1 (Fuji II), 2 (Fuji IX), 3 (Fuji II LC) and 4 (Fuji VIII). After thermocycling, the specimens were immersed in a 2% methylene blue solution, sectioned oro-facially, and analyzed for leakage. The effect of the conditioner was analyzed using a scanning electron microscope (SEM). Results: Significant differences between occlusal and gingival margins were found in all groups ( p < 0.05) except B4, D3, and D4. Comparison of preparation methods (groups A-D) revealed significant differences at the occlusal margin in groups 1 and 3, but in all groups at the gingival margin ( p < 0.05). Laser preparation without conditioning allowed more leakage ( p < 0.05). Comparison of filling materials (groups 1-4) revealed significant differences in groups B and C at the occlusal margin, and in all groups at the gingival margin ( p < 0.05). In these groups, laser-prepared cavities (with or without conditioning) restored with Fuji II LC and Fuji VIII showed the least leakage at both margins. Conclusion: RMGICs allowed less microleakage than CGICs. Complete marginal sealing was not achieved and conditioning is recommended.