13th World Congress for Laser Dentistry

26-28, April 2012

Barcelona, Spain

Meeting Abstract

Sponsors: World Federation for Laser Dentistry

-  Poster 61

TITLE: Effect of CO₂ laser on the inhibition of root surface caries adjacent to glass ionomer cement or composite resin restorations – in vitro Study.

AUTHORS: Souza-Zaroni WC, Zancopé BR, Daniel LC, Araújo FC, Hanashiro FS, Nobre-dos Santos M.

Cruzeiro do Sul University – Dentistry

SOURCE: Med Oral Patol Oral Cir Bucal. 2012 May 1;17(Supplement1):S209.

* doi:10.4317/medoral.17643709

http://dx.doi.org/10.4317/medoral.17643709

Abstract

The present research has investigated the effect of CO₂ laser on the inhibition of root surface demineralization around composite resin and glass ionomer restorations. In order to achieve this purpose, 40 blocks from bovine dental roots have been divided into 4 groups: G1 (negative control): cavity preparation + acid etching + adhesive + composite resin restoration (CR); G2: (positive control) cavity preparation + glass ionomer restoration (GI); G3: same treatment of group 2 + CO₂ laser with 6 J/cm2; G4: same treatment of group 1 + CO₂ laser with 6 J/cm². Next the dental blocks have been submitted to thermal and pH cycling to simulate a high thermal and cariogenic challenge. The root demineralization around the restorations has been quantified by microhardness analysis, and by Quantification of Light Induced Fluorescence (QLF). The results have been submitted to ANOVA and to the test of Games-Howell (p ≤ 0.05). Considering the mineral loss, in the depths between 20µm and 40 µm, the groups have not presented statistical differences. At 60µm from the surface, G2 and G3 ≠ G1, but G4 = G1; at 80 µm the groups G2, G3 and G4 ≠ G1; at 100 µm G4 = G2 = G1 and from 140 to 220 µm G2, G3 and G4 = G1. The averages found by QFL for groups 1, 2, 3 and 4 have been 0.637a; 0.162b; 0.095ab and 0.048c respectively. The irradiation with CO₂ laser has reduced the mineral loss of the root dentine restored with composite resin, even under conditions of high thermal and cariogenic challenges.