13th World Congress for Laser Dentistry

26-28, April 2012

Barcelona, Spain

Meeting Abstract

Sponsors: World Federation for Laser Dentistry

-  Poster 116

TITLE: Bone remodeling and RUNX2 expression, after rapid maxillary expansion in rats, with and without low-level laser therapy.

AUTHORS: Sasso MB, Sasso A, Hirata M.

University of São Paulo- Dentistry School, Ribeirão Preto

SOURCE: Med Oral Patol Oral Cir Bucal. 2012 May 1;17(Supplement1):S264.

* doi:10.4317/medoral.17643764

http://dx.doi.org/10.4317/medoral.17643764

Abstract

The aim of the present in vivo study was to quantitatively evaluate the effects of low-level laser therapy (LLLT) on bone healing after rapid maxillary expansion (RME). A total of 100 rats were assigned to three groups: Negative control with no treatment; Experimental I with RME without LLLT and Experimental II with RME and LLLT (160J/cm²). Bone formation into the mid-palatal suture was investigated using micro-CTscan, histological evaluation and RT-PCR for RUNX2 gene expression. The ANOVA and Tukey tests were used and significance level was set at 5%. The expansion-induced opening of the incisors was similar among the groups. The newly mineralized bone area in both RME groups significantly increased compared with corresponding immediate expansion. When laser and no-laser treatment were compared, LLLT increased bone formation volume at days 7 and 14 (p < 0.05), although at the end of the healing period (21 days) there was no difference between laser and no-laser groups (p > 0.05). Regarding RUNX2 gene expression, both laser and no-laser therapy groups showed a significant increased in RUNX2 expression, compared to the control group, mainly at the initial periods of healing. The results suggest that bone formation after RME was observed within palatal suture and the application of the LLLT influenced bone formation accelerating the process of bone mineralization during the initial experimental phase, although no increased in bone volume could be seen at the end of healing.