The effect of diode laser application on periodontal and biochemical parameters as an adjunctive for non-surgical periodontal treatment in smokers

In this thesis project, the clinical and biochemical effects of adjunctive diode laser decontamination in non-surgical periodontal therapy on the treatment of periodontitis were evaluated. A total of 93 individuals were included in the study, comprising 69 patients diagnosed with Stage III Grade C periodontitis and 24 periodontally healthy individuals. The study groups were classified as follows: the periodontitis group treated with only scaling and root planing (SRP) (smokers: n=18, non-smokers: n=18); the periodontitis group treated with SRP plus adjunctive diode laser application (smokers: n=16, non-smokers: n=17); and the periodontally healthy control group (smokers: n=11, non-smokers: n=13). SRP was performed in a single session using a full-mouth disinfection protocol. The diode laser (940 nm) was applied in a single session immediately after SRP at baseline. Saliva samples were collected from the periodontitis groups at baseline, 1 month, and 3 months, while samples from the healthy controls were obtained at baseline only. Clinical periodontal parameters recorded included probing pocket depth (PPD), number of sites with PPD ≥4, 5, and 6 mm, plaque index (PI), clinical attachment loss (CAL), bleeding on probing (BOP), gingival index (GI), periodontal epithelial surface area (PESA), and periodontal inflamed surface area (PISA). Salivary oxidative stress markers including total oxidant status (TOS), total antioxidant status (TAS), malondialdehyde (MDA), and 8-hydroxy-2'-deoxyguanosine (8-OHdG) were analyzed using the enzyme-linked immunosorbent assay (ELISA) method. A statistically significant improvement in clinical periodontal parameters was observed at 1 and 3 months in all periodontitis patients (p<0.05). At 3 months, the number of sites with PPD ≥4, 5, and 6 mm was significantly lower in laser-treated periodontitis patients compared to those without laser treatment (p<0.05, <0.01, and <0.05, respectively). No statistically significant differences were observed between groups for the other clinical periodontal parameters (p>0.05). At baseline, smokers with periodontitis exhibited significantly higher levels of TOS, TAS, MDA, and 8-OHdG compared to non-smokers with periodontitis and non-smoking healthy individuals (p<0.05). However, at 3 months post-treatment, no significant differences were observed between smoking and non-smoking periodontitis groups for these biochemical parameters (p>0.05). In both laser and non-laser periodontitis groups, MDA levels were significantly reduced at 3 months compared to baseline (p<0.05). In the laser-treated group, 8-OHdG levels were significantly lower at 1 and 3 months compared to baseline (p<0.05), whereas no significant differences were observed across time points in the non-laser group. Compared to non-laser-treated patients, laser-treated patients demonstrated a greater reduction in MDA levels (mean: −56.98% vs. −11.46%) and an increase in TAS levels (mean: +14.98% vs. −9.02%), although these differences were not statistically significant (p>0.05). Statistically significant correlations were found between MDA levels and the number of sites with PPD ≥4 mm (r=0.23), ≥5 mm (r=0.20), PISA (r=0.23), PESA (r=0.21), and PI (r=0.25) (p<0.05). These findings suggest that adjunctive diode laser-assisted SRP may provide additional clinical benefits in reducing deep periodontal pockets in periodontitis patients and exert favorable biochemical effects on certain oxidative stress markers. Although smoking was found to negatively influence oxidative stress markers in periodontitis, it did not show a pronounced effect on the clinical response to non-surgical periodontal therapy. The observed weak yet statistically significant correlations between MDA and certain clinical periodontal parameters indicate that MDA may serve as a potential biomarker in the treatment process of periodontal disease.