Shear bond strength to primary enamel: influence of Er:YAG laser irradiation distance.
OBJECTIVE
The purpose of this study was to evaluate in vitro the influence of Er:YAG laser irradiation distance on the shear bond strength of an adhesive restorative system to primary enamel.


METHODS
Fifty buccal surfaces of extracted human canines were ground and divided into 5 groups (N=10). The control group was etched with 35% phosphoric acid (CA). In the lased groups, the enamel surface treatment was performed with the Er:YAG laser (80mJ/2Hz) by varying the irradiation distance (12, 14, 16, and 17 mm), followed by acid etching. An adhesive agent (Single Bond) was applied on the bonding sites, and resinous cylinders (Filtek Z250) were prepared. Shear bond strength tests were performed in a universal testing machine (0.5 mm/minute). Failure mode was assessed using a X40 magnification stereomicroscope. Data were submitted to statistical analysis by analysis of variance.


RESULTS
The means in MPa were: (1) CA=18.76 (+/-6.68); (2) 12 mm=12.73 (+/-5.46); (3) 14 mm=15.9 (+/-6.81); (4) 16 mm=20.1 (+/-6.94); and (5) 17 mm=15.15 (+/-6.81). There was no statistically significant difference (P<.05) among the tested groups.


CONCLUSIONS
The different Er:YAG laser distance irradiations did not influence the adhesive resistance of the resinous system to enamel, even when compared with the control group (acid etching solely).
Lessa
Fernanda Campos Rosetti
FC
Department of Pediatric Dentistry, School of Dentistry of Araraquara, Brazil.
Mantovani
Carolina Paes Torres
CP
Barroso
Juliana Machado
JM
Chinelatti
Michele Alexandra
MA
Palma-Dibb
Regina Guenka
RG
Pécora
Jesus Djalma
JD
Borsatto
Maria Cristina
MC
D000704:Analysis of Variance; D017438:Bisphenol A-Glycidyl Methacrylate; D003188:Composite Resins; D003481:Cuspid; D001840:Dental Bonding; D003743:Dental Enamel; D045662:Dental Etching / Q000379:methods*; D019232:Dental Restoration Failure; D003793:Dental Restoration, Permanent; D003799:Dental Stress Analysis; D006801:Humans; D053844:Lasers, Solid-State; D019279:Resin Cements; D033081:Shear Strength; D014094:Tooth, Deciduous
D003188:Composite Resins; C444701:Filtek Z250; D019279:Resin Cements; C115612:single bond; D017438:Bisphenol A-Glycidyl Methacrylate