Hybrid layer thickness and morphology: the influence of cavity preparation with Er:YAG laser.
Dentinal surfaces prepared with Er:YAG laser have significantly different characteristics from those prepared with conventional instruments. Different hybrid layer morphologies and thicknesses occur, which may result in differences in the quality of restorations placed on dentinal surfaces prepared with a diamond bur when compared with using an Er:YAG Laser. This study compared the hybrid layer thickness and morphology formed utilizing Scotchbond Multipurpose Plus (SBMP) on dentin prepared with a diamond bur in a high speed handpiece and dentin prepared with an Er:YAG laser. Flat dentin surfaces obtained from five human teeth were treated with the two methods and then with the dentin adhesive system according to the manufacturer's instructions. After a layer of composite was applied, the specimens were sectioned, flattened, polished and prepared for SEM observation. Ten different measurements of hybrid layer thickness were obtained along the bonded surface in each specimen. Results showed that SBMP produced a 3.43 +/- 0.75 microm hybrid layer in dentin prepared with a diamond bur. This hybrid layer was regular and constantly found. In the laser group, the dentin adhesive system produced a 1.54 +/- 0.35 microm hybrid layer that was very irregular and not found constantly. Statistical analysis of variance (p < 0.05) showed that there was a statistically significant difference between the groups. These data indicate that the Er:YAG laser, with parameters used in the experiment, is not a preparation method that allows for a thick hybrid layer formation, which is in opposition to using a diamond bur in a high speed turbine.
Department of Dentistry, Dental School, Fundação Educacional Serra dos Orgãos, Teresópolis, RJ, Brazil. marcosbarceleiro@bol.com.br
Marcos de Oliveira
Mde O
Barceleiro
Jose Benedicto
JB
de Mello
Guilherme Scarpel
GS
de Mello
Kátia Regina Hostílio Cervantes
KR
Dias
Mauro Sayão
MS
de Miranda
Helio Rodrigues
HR
Sampaio Filho
D000704:Analysis of Variance; D003737:Dental Cavity Preparation / Q000379:methods*; D003754:Dental High-Speed Equipment; D006801:Humans; D007834:Lasers; D008963:Molar / Q000737:chemistry; D019279:Resin Cements / Q000737:chemistry*; D016369:Smear Layer
D019279:Resin Cements; C425844:Scotchbond Multi-Purpose Plus