Bonding of self-etching and total-etch systems to Er:YAG laser-irradiated dentin. Tensile bond strength and scanning electron microscopy.
This study investigated the effect of Er:YAG laser on bonding to dentin and the interaction pattern of different adhesive systems with the lased substrate. Tensile bond strength of a self-etching [Clearfil SE Bond (CSEB)] and two total-etch [Single Bond (SB) and Gluma One Bond (GOB)] systems to lased and non-lased dentin was evaluated and the adhesive interface morphology was examined by SEM. Dentin was either treated following the manufacturers' instructions (A) or submitted to Er:YAG lasing (80 mJ; 2 Hz) + adhesive protocol (B). Resin cones were bonded to demarcated dentin sites and tested for tensile strength. For SEM, dentin discs were obtained, bisected and the halves were treated (A or B). The adhesive interfaces were examined. Means of tensile bond strength (in MPa) were: CSEB: (A) 20.65+/-1.81, (B) 14.06+/-1.88; SB: (A) 18.36+/-1.48, (B) 16.19+/-1.90; GOB: (A) 16.58+/-1.94, (B) 14.07+/-2.13. ANOVA and Tukey tests showed that lasing of dentin resulted in a significant decrease in bond strength (p<0.05). In the non-lased subgroups, CSEB had higher bond strength than the total-etch adhesives (p<0.05). Conversely, in laser-ablated specimens, CSEB had the lowest bond strength, while SB had the highest values (p<0.05). Consistent hybrid layers were observed for conventionally treated specimens, whereas either absent or scarce hybridization zones were viewed for lased subgroups. Er:YAG laser irradiation severely undermined the formation of consistent resin-dentin hybridization zones and yielded lower bond strengths. CSEB self-etching primer appeared to be the most affected by the laser ablation on the dentin substrate, resulting in the weakest adhesion.
Ramos
Renata Pereira
RP
Department of Restorative Dentistry, Social and Preventive Dentistry, School of Dentistry of Ribeirão Preto, University of São Paulo (USP), Ribeirão Preto, SP, Brazil.
Chinelatti
Michelle Alexandra
MA
Chimello
Daniela Thomazatti
DT
Borsatto
Maria Cristina
MC
Pécora
Jesus Djalma
JD
Palma-Dibb
Regina Guenka
RG
D001840:Dental Bonding / Q000295:instrumentation*; D045662:Dental Etching / Q000379:methods; D017220:Dentin-Bonding Agents / Q000737:chemistry*; D006801:Humans; D007834:Lasers; D008855:Microscopy, Electron, Scanning; D013499:Surface Properties / Q000528:radiation effects; D013718:Tensile Strength / Q000528:radiation effects
D017220:Dentin-Bonding Agents