Hyaluronic Acid as an Adjunct to Non-Surgical Periodontal Therapy in Smokers

The goal of this clinical trial is to evaluate whether hyaluronic acid (HA) improves periodontal healing in people with periodontal disease who smoke. Moreover, the effects of HA on biomolecules and bacteria levels will be assessed during the follow up period. The main questions it will answer are: Will periodontal sites treated with HA gel after non-surgical periodontal treatment (NSPT) lead to better outcomes in clinical parameters compared to the sites treated with NSPT only in smokers? Will adjunctive use of HA gel reduce oxidative stress markers and bacteria levels during follow-up? Researchers will compare periodontal sites receiving NSPT with adjunctive HA gel application to sites receiving NSPT alone to determine whether HA provides additional clinical, biochemical and microbiological benefits. Participants will: * first receive full-mouth NSPT then, randomization will be performed in selected jaw to determine the test sites. These two interproximal test sites will additionally receive HA gel application. * attend follow-up visits at 1, 3 and 6 months for clinical periodontal measurements and to provide gingival crevicular fluid samples (GCF) and subgingival samples. The GCF samples will be evaluated for Metallothionein (MT) and 8-hydroxy-2'-deoxyguanosine (8-OHdG) levels and subgingival samples for periodontal pathogens.