Influence of Er,Cr:YSGG laser treatment on the microtensile bond strength of adhesives to dentin.
OBJECTIVE
In light of the concept of minimally invasive dentistry, erbium lasers have been considered as an alternative technique to the use of diamond burs for cavity preparation. The purpose of this study was to assess the bonding effectiveness of adhesives to Er,Cr:YSGG laser-irradiated dentin using irradiation settings specific for cavity preparation.


METHODS
Fifty-four midcoronal dentin surfaces, obtained from sound human molars, were irradiated with an Er,Cr:YSGG laser or prepared with a diamond bur using a high-speed turbine. One etch-and-rinse (Optibond FL/Kerr) and three self-etching adhesives (Adper Prompt L-Pop/3M ESPE, Clearfil SE Bond/Kuraray, and Clearfil S3 Bond/Kuraray) were used to bond the composite to dentin. The microtensile bond strength (microTBS) was determined after 24 h of storage in water at 37 degrees C. The Kruskal-Wallis test was used to determine pairwise statistical differences (p < 0.05). Prepared dentin surfaces, adhesive interfaces, and failure patterns were analyzed using a stereomicroscope and Field-emission gun Scanning Electron Microscopy (Feg-SEM).


RESULTS
Significantly lower microTBS was observed to laser-irradiated than to bur-cut dentin (p < 0.05), irrespective of the adhesive employed. Feg-SEM photomicrographs of lased dentin revealed an imbricate patterned substrate and the presence of microcracks at the dentin surface.


CONCLUSIONS
Morphological alterations produced by Er,Cr:YSGG laser-irradiation adversely influence the bonding effectiveness of adhesives to dentin.
Cardoso
Marcio Vivan
MV
Leuven BIOMAT Research Cluster, Department of Conservative Dentistry, School of Dentistry, Oral Pathology and Maxillo-Facial Surgery, Catholic University of Leuven, Belgium.
Coutinho
Edurado
E
Ermis
R Banu
RB
Poitevin
André
A
Van Landuyt
Kirsten
K
De Munck
Jan
J
Carvalho
Rubens C R
RC
Lambrechts
Paul
P
Van Meerbeek
Bart
B
D003188:Composite Resins / Q000737:chemistry; D001840:Dental Bonding; D003737:Dental Cavity Preparation / Q000295:instrumentation / Q000379:methods; D003754:Dental High-Speed Equipment; D003804:Dentin / Q000528:radiation effects* / Q000648:ultrastructure; D017220:Dentin-Bonding Agents / Q000737:chemistry*; D006801:Humans; D053685:Laser Therapy / Q000379:methods; D053844:Lasers, Solid-State / Q000627:therapeutic use; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D019279:Resin Cements / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry; D013499:Surface Properties; D013696:Temperature; D013718:Tensile Strength; D013997:Time Factors; D014867:Water / Q000737:chemistry; D015040:Zirconium / Q000737:chemistry
C505694:Clearfil S3 Bond; C438313:Clearfil SE Bond; D003188:Composite Resins; D017220:Dentin-Bonding Agents; C469607:OptiBond FL; C408584:Prompt L-Pop; D019279:Resin Cements; C083568:Z100 composite resin; D014867:Water; D012822:Silicon Dioxide; D015040:Zirconium