Effects of the root conditioning treatments after Nd:YAG laser irradiation on in vitro human gingival fibroblast attachment to root surfaces

Nd:YAG 레이저조사 후 치근의 처치방법들이 치근면 치은섬유아세포부착에 미치는 영향에 관한 연구

The purpose of this study was to evaluate the biocompatibility of the Nd:YAG lased root surface followed by root planing and/or tetracyline-HCI(T.C.-HCI) conditioning. $30,4mm{\times}4mm$ root segments were obtained from unerupted third molars and 21, periodontally involved root segments. The treatment groups were as follows : (1) healthy root cementum surface groups : 1) control(non-treated group), 2) lased only, 3) lased/root planed, and 4) lased/T.C.-HCI. (2) diseased root cementum surface groups : 1) control(root planed only), 2) lased/root planed, and 3) lased/root planed/T.C.-HCI. The specimens were treated with a Nd:YAG laser using a $320{\mu}m$ noncontact optic fiber handpiece with an energy setting of 1.5W($114.6J/cm^2$), 2.0W($152.9J/cm^2$), 5.0W($382J/cm^2$) for one minute. The fiber was held perpendicular to the petri dish(NUNC) 2cm apart in an attempt to expose the entire root segments equally. Human gingival fibroblasts were cultured from explants of normal interdental gingival tissue obtained during third morlar extraction. The attachment assay was performed with third-generation fibroblasts. The numbers of gingival fibroblasts attached to the root surface were counted on each specimen under the light microscope, and were statistically analyzed by the oneway ANOVA followed by Tukey's test in SPSS/PC+programs. The results were as follows : 1) In healthy root cementum surfaces, lased/root planed groups exhibited a significantly increased fibroblast attachment compared to controls, lased only, and lased/T.C.-HCI groups(p<0.05), 2) In diseased root cementum surfaces, laser treatment followed by root planing and/or T.C.HCl groups exhibited a increased tendency of fibroblast attachment compared to root planed only group. The results suggest that laser treatment followed by root planing and/or T.C.-HCl would appear necessary so as to render the root surface biocompatible.