Comparative evaluation of the effects of low-intesity laser and LED phototherapy on proliferation, metabolism and differentiation of pre-osteoblasts

Abstract

The success of implantology depends on wound healing process and osteogenic potential of cells to induce new bone formation around implants. Among the main effects of phototherapy with low-intensity laser are pain suppression and acceleration of wound healing. The mechanisms by which these effects occur, are still not totally understood. The light emmiting diode (LED) has been showing similar effects to laser. The aim of this study is to evaluate the phototherapy with LED and laser, in different doses on viability, differentiation and enzymatic activity of a pre-osteoblast lineage. (MC3T3 - E1 - subclone 4). The cells will be cultivated in medium. Then they will receive an osteogenic medium (MEM+10% BFS + 8 nucleosides + ascorbic acid and ²-glicerophosphate) to induce differentiation. The irradiation will be done by the bottom of the plaque, punctually with visible red laser (660nm - 40mW), infrared laser (780nm - 40mW) and visible red LED (660nm - 40mW) with 3 and 5 J/cm². Control groups will receive regular and osteogenic medium. The MTT test will evaluate viability, on 24, 48, 72, 96-hour period. The quantification of alkaline phosphatasis will be on 24, 48, 72, 96-hour, 7, 14-day periods. The statistical analysis will be done by ANOVA complemented by Tukey or Kruskal-Wallis complemented by Dunn's tests. The level of significance will be 5% (p<0.05)