Stimulation of human gingival fibroblasts viability and growth by roots treated with high intensity lasers, photodynamic therapy and citric acid

Abstract

Objective: The aim of this study was to compare the effect of root biomodification by lasers, citric acid and antimicrobial photodynamic therapy (aPDT) on viability and proliferation of human gingival fibroblasts (FGH).

Design: Groups were divided in control (CC - only cells), and root fragments treated by: scaling and root planing (positice control - SC), Er:YAG (ER-60mJ,10pps,10Hz,10s,2940nm), Nd:YAG (ND-0.5W,15Hz,10s,1640nm), antimicrobial photodynamic therapy (PDT-InGaAIP,30mW,45J/cm²,30s,660nm,toluidine blue O), citric acid plus tetracycline (CA). Fibroblasts (6th passage, 2×10³) were cultivated in a 24-h conditioned medium by the treated root fragments. Cell viability was measured by MTT test at 24, 48, 72 and 96h. In a second experiment, FGH cells (10⁴) were cultivated on root fragments which received the same treatments. After 24, 48, 72h the number of cells was counted in SEM pictures. In addition, chemical elements were analyzed by energy dispersive spectroscopy (EDS). Data was analyzed by two-way ANOVA (first experiment), repeated measures ANOVA (second experiment) and ANOVA (EDS experiment) tests complemented by Tukey's test (p<0.05).

Results: ND, PDT and CA promoted higher cell viability (p<0.05). ND and ER groups presented higher number of cells on root surfaces (p<0.05). ER group presented higher calcium and CA group a higher carbon percentages (p<0.05).

Conclusions: All treatments but scaling and root planing stimulated fibroblast viability while Er:YAG and Nd:YAG treated root surfaces presented higher number of cells.

Keywords: Cell culture techniques; Demineralization; Lasers; Photochemotherapy.