Sir,Recently an interesting article entitled “Serum level of antioxidants and superoxide dismutase (SOD) in periodontitispatients with diabetes type 2” by Thomas et al.[1] was published in Jul-Aug 2014 issue. The findings of this study suggested that the serum total antioxidant capacity was decreased in chronic periodontitis (CP) as well as in diabetes mellitus with chronic periodontitis (DMCP). The levels of SOD were found to be decreased in CP, but increased or similar to periodontally healthy (PH) group in DMCP group due to the adaptive response.A comparable study[2] was published by our group, in which the serum levels of tissue damage indicator malondialdehyde levels were found to be increased in diabetes and CP. SOD levels did not differ among CP, DMCP and PH groups in red blood cell lysate while in saliva, the SOD values were found to be significantly reduced in CP and DMCP groups.The two-way relationship between diabetes and periodontitis is well-known, but the exact basic mechanism is still not well determined. The various theories proposed include the role of increased oxidative stress, poor host defense, chronic systemic inflammation, vasculopathy, and diminished salivary secretion.[3]The above studies give support to the hypothesis that oxidative stress is one key factor in the diabetes and periodontitis relationship. The deranged values of the antioxidants suggest that these may be of help as potential biomarkers in diabetics with CP so that early intervention and closer follow-up be maintained for these patients. Furthermore, short term antioxidant supplementation either locally or systemically may be of value which should be further investigated.