The Effect Of Co2 Laser On The Microhardness Of Human Dental Hard Tissues Compared With That Of The High-Speed Drill

Objective: The purpose of this study was to examine the effect of 9.6-mu m CO2 laser energy on the microhardness of human dental hard tissues compared with that of high-speed drill cavity preparation, and to determine the applicability of this laser in clinical treatment. Materials and Methods: A total of 10 caries-free human single-rooted teeth were used for this study. The crowns were resected and the roots were longitudinally sectioned into two halves. In each slice one half of the enamel and the dentin were treated with 9.6-mu m CO2 laser irradiation, and in the other half the enamel and dentin were treated with a high speed drill, each half for 3 s. Following treatment, the samples were polished and tested for microhardness. The results were compared using analysis of variance. Results: Statistically significant differences in dentin microhardness were found between specimens treated with 9.6-mu m CO2 laser energy as compared with specimens treated with the high-speed drill (p = 0.0156). There were no statistically significant differences in enamel microhardness between specimens treated with 9.6-mu m CO2 laser energy and specimens treated with the high-speed drill. Conclusion: The clinical use of 9.6-mu m CO2 laser energy for cavity preparation should be further analyzed, and compared with different types of lasers used in dentistry, such as 10.6-mu m CO2 or Er-YAG.