Objective The aim of this cross‐sectional study was to evaluate the association between periodontitis and different severities of chronic kidney disease (CKD) in predialytic patients. Materials and Methods Demographic, socioeconomic, and medical data of 139 patients from the nephrology service of one university hospital in Porto Alegre, Brazil, were obtained through interview and clinical records. Full‐mouth six‐sites per tooth periodontal examinations were performed. Associations between periodontitis, stages of CKD, and estimated glomerular filtration rate (eGFR) were estimated by multivariable models adjusted for sex, smoking, vitamin D supplementation, physical activity, and renal treatment duration. CKD was classified based on eGFR (<60 ml/min/1.73 m2) estimated by the Chronic Kidney Disease Epidemiology Collaboration equation. Results Patients with severe periodontitis, compared to those without severe periodontitis, had 2.8 (95% CI: 1.25–6.62) and 3.4 (95% CI: 1.27–9.09) times higher risk of being in stages 4 and 5 of CKD, respectively. Having ≥ 2 teeth with clinical attachment loss (CAL) ≥6 mm increased 3.9 times the risk of being in stage 5 of CKD. Patients with severe periodontitis and ≥2 teeth with CAL ≥ 6 mm had 4.4 ml/min/1.732 and 5.2 ml/min/1.732 lower eGFR (p‐values < .05), respectively. Conclusion Severe periodontitis was associated with poor renal conditions in predialytic CKD patients, strengthening the importance of periodontal evaluation in such patient population.

Abstract:The aim was to correlate alveolar bone loss in the buccal/palatal and the mesial/distal surfaces of upper molars in rats. Thirty-three, 60-day-old, male Wistar rats were divided in two groups, one treated with alcohol and the other not treated with alcohol. All rats received silk ligatures on the right upper second molars for 4 weeks. The rats were then euthanized and their maxillae were split and defleshed with sodium hypochlorite (9%). The cemento-enamel junction (CEJ) was stained with 1% methylene blue and the alveolar bone loss in the buccal/palatal surfaces was measured linearly in 5 points on standardized digital photographs. Measurement of the proximal sites was performed by sectioning the hemimaxillae, restaining the CEJ and measuring the alveolar bone loss linearly in 3 points. A calibrated and blinded examiner performed all the measurements. Intraclass Correlation Coefficient revealed values of 0.96 and 0.89 for buccal/lingual and proximal surfaces, respectively. The Pearson Correlation Coefficient (r) between measurements in buccal/ palatal and proximal surfaces was 0.35 and 0.05 for the group treated with alcohol, with and without ligatures, respectively. The best correlations between buccal/palatal and proximal surfaces were observed in animals not treated with alcohol, in sites both with and without ligatures (r = 0.59 and 0.65, respectively). A positive correlation was found between alveolar bone loss in buccal/palatal and proximal surfaces. The correlation is stronger in animals that were not treated with alcohol, in sites without ligatures. Areas with and without ligature-induced periodontal destruction allow detection of alveolar bone loss in buccal/palatal and proximal surfaces.