Endoplasmic Reticulum Stress Response in Periodontal Disease

Inclusion Criteria: Inclusion criteria for the Healthy Control group were: presence of ≥ 20 teeth in the mouth, probing pocket depth (PPD) ≤ 3 mm, the percentage of bleeding sites for the whole mouth \< 10%, and, on radiographic examination, a distance of ≤ 3 mm between the cemento-enamel junction and the alveolar bone crest in 95% of all teeth. Inclusion criteria for the Gingivitis group were: presence of ≥ 20 teeth in the mouth, PPD ≤ 3 mm, % of bleeding sites for the whole mouth ≥ 10%, and, on radiographic examination, a distance of ≤ 3 mm between the cemento-enamel junction and the alveolar bone crest in 95% of all teeth. Inclusion criteria for the Stage 3 Periodontitis group were: presence of ≥ 15 teeth in the mouth, more than 30% of teeth affected by periodontal disease, affected teeth exhibiting probing depths of 6 mm or more and clinical attachment loss (CAL) of ≥ 5 mm, vertical bone loss of 3 mm or more, class 2 or 3 furcation involvement, and radiographic evidence of alveolar bone loss extending to the middle third and beyond (33%) in the relevant teeth Exclusion Criteria: Exclusion criteria for all groups were defined as: presence of any systemic disease, regular use of any medication, smoking, pregnancy or lactation, periodontal treatment within the last 6 months, antibiotic use within the last 6 months, and the presence of prosthetic restorations on the teeth to be sampled.