Impact of e-cigarette smoking on healing response to non-surgical periodontal therapy in management of stage II periodontitis: a prospective controlled clinical study with biochemical assessment

Background Smoking, both traditional and electronic, remains a major public health concern with profound implications for systemic and oral health. Inflammation, tissue degradation, and alveolar bone loss are characteristic features of periodontal disease, which is significantly correlated with traditional smoking and vaping. This study aimed to compare the effect of vaping vs. traditional smoking on clinical and biochemical outcomes in non-surgical periodontal therapy (NSPT). Methods This prospective controlled clinical study with biochemical assessment involved 117 participants diagnosed by stage II periodontitis. Participants were allocated into 3 equal groups: Group I: Traditional smokers, group II: E-cigarette users and group III: Non-smokers (control group). At baseline and 8 weeks following NSPT (scaling), probing pocket depth (PPD), clinical attachment level (CAL), bleeding on probing and, plaque index were assessed. Results The overall regression model was statistically significant. Baseline probing depth emerged as the strongest baseline covariate independently predicting post-treatment probing depth ( P < 0.001). After adjusting for baseline clinical and biochemical covariates, smoking exposure status remained a statistically significant independent determinant of post-treatment pocket depth. Compared to non-smokers, traditional tobacco smoking demonstrated a significant positive association with higher residual probing depth ( P = 0.005). Similarly, electronic cigarette use was an independent predictor of increased residual probing depth ( P = 0.011). Conclusions NSPT was associated with improvement in clinical periodontal and inflammatory parameters over the 8-week follow-up. However, substantial baseline differences between exposure groups warrant baseline-adjusted interpretation of treatment outcomes. Trial registration This trial was registered at ClinicalTrials.gov under registration number NCT07668947 on 16 June 2026.