Objective: This research evaluated the periodontal conditions of teeth with restored and non-restored non-carious cervical lesions (NCCLs). Method and Materials: Thirty-seven patients presenting at least two contralateral teeth with NCCL (one restored and another non-restored) were selected. Non-restored NCCL teeth were classified as a control group, while the contralateral teeth restored within at least 3 months with a Class 5 restoration located near the gingival margin were classified as the test group. The periodontal parameters analyzed were visible plaque, probing depth, bleeding on probing, gingival recession, clinical attachment level, and width of keratinized tissue. Restorative parameters such as finishing/polishing, overhanging margins, and terminal restoration level were also examined. Statistical analysis included the comparison of periodontal and restoration parameters between groups as well as associations between these parameters. Data were statistically analyzed by the Wilcoxon, Fisher's exact, Chi-squared, and Mann-Whitney tests. The significance level was set at 5% (? .05). Results: Statistically significant differences between test and control groups were observed for visible plaque (P = .002), bleeding on probing (P = .041), and width of keratinized tissue (P = .009). Other clinical parameters such as probing depth (P = .812), gingival recession (P = .571), and clinical attachment level (P = .484), as well their associations did not show any statistically significant differences (P > .05). Conclusion: Restorative treatment (Class 5) of teeth with NCCL partially influenced the clinical parameters. Keywords: non-carious cervical lesions, periodontal disease, plaque, restoration