Obesity is characterized by the abnormal or excessive deposition of fat in the adipose tissue. Its consequences go far beyond adverse metabolic effects on health, causing an increase in oxidative stress that leads not only to endothelial dysfunction but also to negative effects in relation to periodontitis, because of the increase in proinflammatory cytokines. Thus, obesity appears to participate in the multifactorial phenomenon of causality of periodontitis through the increased production of reactive oxygen species. Within this context, this paper aims to highlight, by analysis and description of previous studies, the interface between obesity and periodontitis, with emphasis on oxidative stress and the inflammatory response.

Background Bariatric surgery influences the intake and absorption of nutrients, which, when associated with vomiting, can damage the oral cavity. The serum concentrations of vitamin C and myeloperoxidase (MPO) and oral clinical manifestations were examined in patients 2 years after Roux‐en‐Y gastric bypass (RYGB). Methods Clinical prospective study with control group (CG; n = 26), assessed only once, and the bariatric group (BG; n = 26), assessed in the basal period and at 12 and 24 months after surgery. The mean ages in the CG and BG were 37.8 ± 1.51 and 39.6 ± 1.93 years, respectively, and their body mass indices were 22.07 ± 0.29 and 45.62 ± 1.46 kg/m2, respectively. Results At 12 months after surgery, increased episodes of vomiting (P < .001) and dental hypersensitivity (P = .012) were observed, with a reduction in the saliva‐buffering capacity of 21.3% ± 2.9% (P = .004). At 24 months after RYGB, a significant reduction in serum vitamin C was detected (32.9% ± 5.3%, P < .001), and MPO values were higher than in the basal period (P = .032). With regard to oral hygiene habits, 92.3% of patients reported frequent tooth brushing and 96.1% used fluoride, which were similar across the 2 years. However, dental hypersensitivity (P = .048) was significantly increased than baseline. Conclusions The results demonstrated that vitamin C deficiency and increased vomiting after gastric bypass for morbid obesity may contribute to increased periodontal disease. The fact that it is impossible to determine which factor or factors (diet, poor compliance with supplementation, vomiting, poor oral hygiene) contributed to the dental problems in these patients is a shortcoming of the report.