• acute inflammation
• C-reactive protein
• Gingivitis
• quality of life

Aim: This study aimed to evaluate the impact of oral hygiene changes resulting in a drastic plaque and gingival inflammation reduction on the markers of systemic inflammation and on the indicators of oral health-related quality of life and other aspects related to overall well-being.

Materials & Methods: This was a randomized clinical trial with one-month follow-up, including patients affected by generalized gingivitis, and randomly allocated to one of two treatment arms. The test group comprised of 70 patients receiving intense oral hygiene instructions (OHI) as well as oral hygiene (OH) tools, consisting of a powered toothbrush with a rotation oscillation action, a tube of stannous fluoride dentifrice, and two dispensers of waxed interdental floss. The control group involved 70 patients not receiving OHI or OH tools and continuing with their routine habits. The test group received intensive OHI at baseline when professional supragingival scaling and polishing were performed in both groups. The test group patients were seen again every week for oral hygiene reinforcement (T7, T14, and T21). Periodontal and anthropometric measurements, as well as vital signs and overall well-being-related parameters, were collected at baseline and one-month follow-up visit. Serum samples were drawn at baseline for high-sensitivity C-reactive protein (hs-CRP), interleukin-6 (IL-6), and vitamin D (25(OH)D3) and at one-month follow-up visit for hs-CRP and IL-6.

Results: One hundred and forty consecutive patients were enrolled and completed the study providing data for the final analysis. Both groups were comparable for all measured characteristics at baseline. Periodontal treatment was successful in both groups that exhibited an important reduction in measured clinical parameters. Drastic plaque and gingival bleeding reduction in the test group led to a complete clinical resolution of gingivitis. The tested protocol elicited a significant intragroup decrease in hs-CRP (p<0.01) and IL-6 (p<0.01) at one month, which was not observed in the control group. Moreover, a statistically significant difference in levels of hs-CRP was observed between the two groups, with a higher decrease for the test group at one month (p<0.05). Vitamin D serum levels assessed at baseline in the test group were 24.65 ± 4.90 μg/L, while the control group had 25.25 ± 4.79 μg/L. Logistic multivariate regression model identified a threshold for full-mouth bleeding score (FMBS) ≤ 8%, for which the odds ratio of having both, the CRP ≤ 0.3 mg/dL and IL-6 ≤ 6.4 pg/mL was 23.48 ± 9.37 (p<0.01). Additionally, the tested protocol resulted in a significant improvement in oral health-related quality of life, evaluated with the Oral health impact profile-14 questionnaire (OHIP-14). Indeed, the test group had the improvement of the overall OHIP-14 score at one month compared to baseline (p<0.0001), and to the control group at one-month follow-up (p<0.001). These improvements in the overall OHIP-14 score at one month could not be observed for the control group (p=0.11), neither could be observed an improvement in any of the assessed 14 questions at one-month follow-up.

Conclusions: The tested protocol of drastic plaque and gingival inflammation reduction elicited a significant decrease in systemic inflammation exhibited through serum reduction in hs-CRP and IL-6 at one-month follow-up. Moreover, it produced significant improvements in oral health-related quality of life in healthy, adult patients affected with generalized gingivitis. A full mouth bleeding score equal to or less than 8% is associated with the probabilities that the periodontal treatment reduced both, the levels of the hs-CRP and IL-6 below the reference threshold observed in an adult, healthy population.