Effect of Interleukin-1 Genotype on Initial Periodontal Therapy

Objectives: To investigate the effect of IL-1 genotype on the results of initial periodontal therapy. Methods: The study covered 30 non-smokers aged 39 to 74 with chronic periodontitis. Clinical measurements performed at baseline, 6-8 weeks and 16-18 weeks following treatment included measurement of probing depth (Florida Probe), change in attachment level between examinations (Florida Disk Probe), plaque and bleeding on probing. Treatment comprised of full-mouth scaling and root planing, oral hygiene instruction and motivation. Following the final examination, patient’s genotype for IL-1 was identified by PST. Results were analyzed by Wilcoxon’s signed ranks test. Results: 16 patients were genotype IL-1(+), and 14 IL-1(-). Both genotypes showed a decrease in probing depth at the 3 successive examinations: 3.5mm (baseline), 2.7mm (6-8 weeks), 2.6mm (16-18 weeks) for IL-1(+); 3.4mm (baseline), 2.4mm (6-8 weeks), 2.3mm (16-18 weeks) for IL-1(-). No significant differences were found between genotypes. Changes in probing attachment level from baseline were similar for IL-1(+) and IL-1(-) patients at all time points (gain of 0.7mm at 6-8 weeks for IL-1(+) patients; 0.8mm for IL-1(-) patients, p>0.05). Plaque decreased from 54.8% to 37.2% to 36.2% in IL-1(+) patients, and from 54.9% to 37.1% to 38.4% for IL-1(-) patients. Differences between groups were not significant. Bleeding on probing decreased in IL-1(+) patients from 53.0% to 22.6% to 22.0%, and in IL-1(-) patients from 47.8% to 18.4% to 18.1%. Differences between groups were not significant. Conclusions: Results showed a similar improvement in periodontal health following initial periodontal treatment in both patients with IL-1(+) and IL-1(-) genotype. No significant differences were found between genotypes for any of the parameters measured. Results of this study confirm the short-term efficacy of initial periodontal treatment regardless of patients’ IL-1 genotype.