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
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.


CONCLUSIONS
RMGICs allowed less microleakage than CGICs. Complete marginal sealing was not achieved and conditioning is recommended.
Delmé
Katleen I M
KI
Department of Operative Dentistry and Endodontology, Ghent Dental Laser Center, Dental School, Ghent University, Gent, Belgium. katleen.delme@ugent.be
Deman
Peter J
PJ
De Bruyne
Mieke A A
MA
De Moor
Roeland J G
RJ
D003736:Dental Cavity Lining; D003737:Dental Cavity Preparation; D003743:Dental Enamel / Q000648:ultrastructure; D003763:Dental Leakage; D003804:Dentin / Q000648:ultrastructure; D005899:Glass Ionomer Cements / Q000737:chemistry; D006801:Humans; D066298:In Vitro Techniques; D053844:Lasers, Solid-State; D008855:Microscopy, Electron, Scanning
D005899:Glass Ionomer Cements; C084541:Fuji glass-ionomer lining cement