RESUMO
Nitric oxide (NO) is a short-lived intercellular messenger with multiple biological implications, such as regulation of blood pressure, inhibition of platelet adhesion and aggregation, bacterial-challenge and cytokine stimulation, and regulation of mineralized tissue function. NO synthase (NOS) catalyses the conversion of cationic amino acid L-arginine to L-citrulline and NO. Recently there is an increasing interest in the role of NO in the physiopathology of periodontal disease (PD). PD is a chronic inflammatory disease of the attachment structures of the teeth, which is found in 40-50% of most adult populations worldwide and may result in tooth loss. The potential sources of NO in periodontum are inflammatory cells, keratinocytes, fibroblasts, osteoclastics and blood vessels. Etiological periodontitis factors, such as inflammatory cytokines and periodontopathogens are evolved in enhanced NO levels, which may be part of a nonspecific natural defense mechanism or may lead to periodontal damage. This review gives detail of recent research data focusing on NO bioavailability and its involvement in periodontitis pathogenesis and the modulation of NO for better control of this disease.