Abstract:

Objective:The purpose of this study was to evaluate the effects of squamous cell carcinoma on oral bacteria.Methods:This study investigated the microbial contents of the plaque on the surfaces of oral squamous cell carcinomas. Samples were obtained from the central surface of lesions, contiguous healthy mucosa and saliva of 42 patients with oral squamous carcinoma before and after operation.Results:The median of bacterial colony forming units per milliliter (CFUs/ml) of saliva before operation was 8.10@108CFUs/ml. The median of CFUs per square centimeterof the tumor surface was5.21@105CFUs/cm2whichwas signif- icantly higher than that of the healthy (the control) mucosa (1.77@104CFUs/cm2,P=0.0001). The CFUs per square cen- timeterof mucosa surface at the operative zone was 4.34@105CFUs/cm2which was also significantly higher than that of the healthy (control) mucosa(7.24@104CFUs/cm2,P=0.0001).Conclusion:Oral carcinoma can break the balance of oral mi- croflora, which may be one of the reasons leading to the high susceptivity of these compromised patients to systemic infection.

Key words: oral microflora, oral squamous cell carcinoma, saliva, oral mucosa