13th World Congress for Laser Dentistry

26-28, April 2012

Barcelona, Spain

Meeting Abstract

Sponsors: World Federation for Laser Dentistry

-  Poster 127

TITLE: Evaluation of Oral Chemical Carcinogenesis on the Hamster Cheek pouch model Irradiated with Laser Phototherapy.

AUTHORS: Oliveira SCPS, Monteiro JSC, Oliveira PC, Marques AMC, Pinheir ALB, Santos JN.

Center of Biophotonics - School of Dentistry - Federal University of Bahia

SOURCE: Med Oral Patol Oral Cir Bucal. 2012 May 1;17(Supplement1):S275.

* doi:10.4317/medoral.17643775

http://dx.doi.org/10.4317/medoral.17643775

Abstract

Aim: This study aimed to evaluate, histologically, the effect of LLLT (λ660nm) on DMBA chemically induced lesions of the oral mucosa of hamsters. Background: Squamous cell carcinoma is the most common neoplasm of the oral cavity. There are evidences that the LLLT affects similarly neoplasic and non-neoplasic cells. Material and Methods: Cancerous lesions were induced on the cheek pouch of 15 Syrian golden hamsters by using DMBA 3 times a week for 8 weeks. At the end of the cancer induction (8 w), animals of GI were killed and the presence of tumors confirmed. Animals of GIII were irradiated (λ660nm, 30mW, CW, Ø= 3mm, Area: 0.07cm², 424mW/cm², 133s, 56.4J/cm², 4J) at every other day for 4 weeks. GII suffered no interventions for the same period. Samples were taken and underwent histological analysis. Results: GI showed 100% of well-differentiated SCC. GII showed 20% of moderately differentiated and 80% well-differentiated SCC. GIII showed 40% of well differentiated, 40% poorly differentiated and 20% moderately differentiated SCC. Significant differences (p= 0.02) on the amount of well-differentiated SCC were seen between GI and GIII and GIII and GII (p=0.04). Significant difference was also seen between GIII and GI and GII on regard the amount of poorly differentiated tumors (p=0.04). Conclusion: It is concluded that LLLT, within the parameters specified in the present study, caused a significant progression of the severity of SCC of the oral cavity on hamsters.