13th World Congress for Laser Dentistry

26-28, April 2012

Barcelona, Spain

Meeting Abstract

Sponsors: World Federation for Laser Dentistry

-  Poster 31

TITLE: Er,Cr:YSGG Laser Dentin Conditioning Influence on Glass Ionomer Cement Bond Strength.

AUTHORS: Garbui BU, Azevedo CS, Zezell DM, Matos AB.

SOURCE: Med Oral Patol Oral Cir Bucal. 2012 May 1;17(Supplement1):S179.

* doi:10.4317/medoral.17643679

http://dx.doi.org/10.4317/medoral.17643679

Abstract

Introduction: Conventional glass ionomer cements (CGIC) chemically bonds to tooth structure. To improve it, pretreating with polyacrylic acid is recommended, however, it is not always commercially available. Dentine pretreatment with laser irradiation has been consi-dered as an alternative method since it has also the ability of bacterial reduction, which is essential in atraumatic restorative treatment (ART). Objective: Evaluate the influence of Er,Cr:YSGG laser pretreatment with two different irradiation parameters on bond strength (BS) of CGIC. Methods: Fifty one third molars were divided into 3 groups pretreated with one of the following: (G1-control group) no pretreatment, (G2) Er,Cr:YSGG laser irradiation at 0.5W, 25mJ, 20Hz or (G3) at 1.5W, 75mJ, 20Hz. SEM evaluation (n=2) of pretreated dentine and microshear bond strength test (n=15) were performed after 24hs of water immersion. To build the specimens to microshear test, CGIC (Ketac Molar Easy Mix) was used. Results: Specimens of G2 presented the highest BS results (10.50MPa +/-0.84), while G3 showed the lowest value (2.94MPa +/-0.50). SEM analysis of G1 showed smear layer covered entire dentine surface, while in groups G2 and G3 opened dentinal tubules could be detected. Laser pulses could be distinguished in G2, but not in G3, suggesting that higher energy parameter can broadly disturb dentin, affecting bonding to CGIC. Conclusion: Er,Cr:YSGG laser dentin pretreatment at 0.5W energy parameter increased BS of CGIC.