SOD1 and periapical granuloma: Our results were contradictory in this aspect, to reported by Malik et al. (2020) since the levels of SOD and GPx (57.934 and 102.9 U/mL, respectively) were superior in PPL patients and they reported a significant decrement in patients compared to controls in levels of SOD (0.03 and 0.11 nmol/ml, respectively) and GPx (5.88 and 7.87 nmol/ml, respectively) (9) Probably by MDA may reduce the activity of glutathione peroxidase in periapical granulomas, as it has been reported by Ayala et al. (10).