Microhardness of Enamel Adjacent to Orthodontic Brackets After CO2 Laser Irradiation and Fluoride Application

Abstract

This study evaluated the effectiveness of carbon dioxide (CO2) laser combined or not with fluoride application on the surface microhardness of enamel adjacent to orthodontic brackets. Fifteen human molars were selected from which 30 enamel fragments measuring 4 mm2 were obtained. The fragments were embedded in PCV tubes with acrylic resin and prepared using water abrasive paper, felt disks and alumina. Orthodontic brackets cut in half were bonded to enamel and 3 microhardness readings were performed on the adjacent surface, as follows: initial, after cariogenic challenge and final. The specimens were divided into the following 3 groups (n=10): Group C: control, Group L: irradiated with CO2 laser, and Group FL: topical fluoride application and CO2 laser irradiation. After initial reading, the specimens were placed in a demineralizing solution for 32 h and the second reading was to verify if demineralization was uniform in all groups. After the treatments, the specimens were submitted to DES-RE cycling for 8 days followed by final surface microhardness reading. The data were analyzed statistically using ANOVA and Duncan test (α=0.05). At the final measurement Group FL obtained higher microhardness value than Groups C and L (p<0.05). Groups L and FL were statistically superior to Group C (p<0.05). Irradiation with CO2 laser around orthodontic brackets combined or not with topical fluoride application was effective to increase the surface microhardness of enamel.

The Effect of the Er:YAG Laser and MI Paste Plus on the Treatment of White Spot Lesions

“…Previous studies have generally used high-power lasers such as Er:YAG and CO2 to prevent the occurrence of these lesions. 16,[21][22][23][24][25] Few studies, however, have used these lasers for the sake of treatment. 24,26,27 In the study of Bevilacqua et al and some similar ones, the use of erbium lasers to prevent caries has been reported to be effective.…”

Effect of CO2 Laser and Fluoride Varnish Application on Microhardness of Enamel Surface Around Orthodontic Brackets

“…It is reported that laser increased fluoride uptake. 29,30 Stangler et al, 31 Nakagaki et al 32 and Featherstone et al 33 assessed the effect of CO 2 laser and fluoride combination and reported it to be more than fluoride or laser alone. With respect to the order of fluoride and laser in the combination, EstevesOliveira et al 34 found that when fluoride is used before laser irradiation, it increased enamel microhardness more than when laser is used before fluoride application.…”

Evaluation the effect of the diode laser irradiation associated with photoabsorbing cream containing remineralizing agents on microhardness, morphology and the chemical structure of early enamel caries

“…These lesions are more frequently observed in patients who have poor dental hygiene or in those undergoing fixed orthodontic treatment. WSLs not only produce an unaesthetic and disturbing appearance, but also can progress to caries cavities on the tooth surface ( 1 , 2 ).…”

“…Laser irradiation has been applied in recent years for its possible strengthening effect on tooth structure. It has been indicated that high power lasers such as CO2 laser can increase enamel surface hardness and reduce its solubility ( 2 , 10 , 11 ). However, high power lasers should be applied consciously and with low energy level to preserve enamel integrity and minimize the creation of porosities on the tooth surface ( 12 ).…”