In situ effects of CO2 laser on secondary caries

Objectives: This in situ study investigated the effect of CO2 laser (10.6µm) on the reduction of enamel demineralization on cavity margins around composite-resin restorations.

Methods: During 14-day experimental period, 14 volunteers wore palatal appliances containing 4 human dental enamel slabs with restored enamel cavities, which were assigned to treatment groups, as follows: (1) control (no laser irradiation) and (2) CO2 laser irradiation on the cavosurface angle of cavity. The cavities were restored with a resin-based composite, according to the manufacturer's specifications. A 20% sucrose solution was dripped onto the slabs 8X/day and the volunteers used fluoridated dentifrices 3x/day. Enamel mineral loss, at distances of 25 and 50 µm from the restoration margins, was assessed by cross-sectional microhardness analysis. Results: CO2 laser irradiation had statistically significant effect on the reduction of the carious process at a distance of 25 µm (at 10, 20 and 40 µm depths) and 50 µm (at 10 µm depth) from the cavity margin (T-test, p<0.05).

Conclusions: Irradiation of the cavosurface margin of cavities, using a pulsed CO2 laser, was able to inhibit enamel demineralization around composite restorations being a promising alternative in controlling secondary caries.