Respective Effects of Oral Hygiene Instructions and Periodontal Nonsurgical Treatment (Debridement) on Clinical Parameters and Patient-Reported Outcome Measures with Respect to Smoking

Background: Oral hygiene instructions (OHI) and periodontal nonsurgical treatment (PNST) play pivotal roles in the management of periodontitis. The study aims to discern their respective effects on periodontal clinical parameters and patient-reported outcome measures (PROMs). Methods: Ninety-one patients were included, 34 non-smokers (NS), 25 former smokers (FS) and 32 current smoker (CS). Clinical parameters such as probing depth (PD) and bleeding on probing (BOP) were collected, and the periodontal inflamed tissue area (PISA) was calculated. Clinical parameters and PROMs were recorded before and after receiving OHI, with electronic tooth brush and interdental brushes, as well as 3 months after debridement. Results: Smokers presented a significantly higher proportion of severe periodontitis (64.7%) with generalized extension (76.5%) and with a rapid rate of progression (97.1%) compared to NS and FS. OHI led to a significant decrease of PD, BOP, and PISA (p < 0.0001) only in NS and FS. Debridement reduced PD and the percentage of PD >6 mm in all groups (p < 0.0001). OHI induced significant improvement of oral hygiene, frequency of interdental cleaning, and PROMs (p < 0.0001). Further debridement induced significant additional improvement PROMs in FS and NS (p < 0.0001). Conclusion: OHI and debridement improved periodontal clinical parameters and PROMs in both NS and FS. Former smokers had comparable outcomes to non-smokers, suggesting that smoking cessation should be encouraged.