Low Laser Therapy Plus Non-Surgical Periodontal Treatment Reduces Interleukin-1 Beta Serum Levels

Objectives: Periodontal disease is associated to widespread systemic inflammation, and further to both cardiovascular morbidity and mortality. Data from intervention studies demonstrated the beneficial effects of periodontal therapy in reducing vascular diseases. The present study was aimed to explore whether low-level Laser therapy as an adjunct to scaling and root planning reduces serum levels of inflammatory cytokines. Material and Methods: Thirty patients were enrolled. All recruited participants underwent blood sampling and dental inspection for periodontal indexes measurement. Plaque index, gingival index and probing depth were employed as measures of periodontal disease. Afterwards, patients underwent scaling and root planning plus low-level Laser therapy. Inflammatory biomarkers and periodontal indexes were measured before treatment and twenty weeks after treatment. Results: Plaque index, gingival index and probing depth largely improved at the follow-up visit, resulting more than halved from the baseline. Furthermore, a significant reduction of serum interleukin-1 beta has been observed (1.1 [SD 2.1] vs 0.5 [SD 1.3], P = 0.04), whereas serum interleukin-6 levels remained substantially unchanged. Blood C-reactive protein levels decreased at the follow-up, but not reaching statistical significance. Conclusions: therapy addressed to a local improvement of periodontal disease gives a reduction of systemic inflammation, possibly beneficial for cardiovascular health. D e n t a l a n d O r a l I m p l a n t s ISSN NO: 2473-1005 Research Article DOI : 10.14302/issn.2473-1005.jdoi-15-730 Corresponding Author: Maria Serena De Franceschi, Institute of Dentistry, Department of Clinical and Experimental Medicine, “Magna Græcia” University, Viale Europa, 88100 Catanzaro, Italy, Phone: +3909613697664; Fax: +3909613697250, Email: numemaca@yahoo.it


Introduction
Periodontal disease is an inflammatory condition characterized by gingival inflammation and progressive destruction of the supporting tissues of the teeth. 1 In the United States, it is reported a prevalence of about 47% in adults aged ≥ 30 years, whereas the 64% of adults aged ≥65 years have moderate/severe periodontitis. 2 Periodontal disease is associated with widespread systemic inflammation, as demonstrated by the increase in circulating C reactive protein and inflammatory cytokines. 3,4 Systemic inflammation is a potential contributor to atherosclerosis and/or thrombosis, pathologic bases of cardiovascular diseases. 5 In fact, several studies indicate that plasma levels of inflammatory biomarkers, such as CRP, IL-6 or IL-1β, can be useful in identification of individuals at high risk for future cardiovascular events. 6 Indeed, raised serum proinflammatory cytokines impair nitric oxide (NO) synthesis (an important vasodilator compound) and enhance endothelin-1 (ET-1) production. [7][8][9] This important topic is reinforced by evidences suggesting that non-surgical periodontal treatment should be able to restore the anti-atherogenic properties of the endothelium and to reduce serum cytokines levels. 10,11 Interestingly, it seems that low levels Laser treatment (LLLT), as an adjunctive therapy to nonsurgical periodontal treatment, improves periodontal healing and reduces interleukin burden locally, in the gingival crevicular fluid. 12 It is not known if this improvement is also followed by a reduction of inflammation into the blood of systemic circulation.
The aim of the present investigation was to test the effect of periodontal therapy by Laser plus nonsurgical periodontal treatment on serum levels of inflammatory cytokines in patients with periodontal disease.

Patients and study design
The study was a prospective intervention trial Cedex -France). For IL-1beta, the overall intraassay coefficient of variation has been reported to be 4.5%.
Clinical examination was held as previously described. 13 Briefly, height and weight were detected using standard methods, and body mass index computed as weight (kg) divided by height squared (m 2 ). Systolic (SBP) and diastolic blood pressure (DBP) was measured with a standardized sphygmomanometer on the right arm after the participant rested for at least Finally, 11 were currently smokers and 8 were obese.
These clinical features were unchanged at the end of the study (data not shown). Table 2 reports periodontal indexes (expressed as mean and sum) and inflammatory markers of patients at the baseline and twenty weeks after therapy. As shown, periodontal indexes were largely improved at the follow-up visit, decreasing of 55 -60% from the baseline ( Figure 1).
Regarding inflammatory markers, it has been observed a significant reduction of serum interleukin-1β twenty weeks after therapy (p = 0.04), whereas serum IL-6 levels remained substantially unchanged. Serum hs-CRP levels decrease at V2, but not reaching statistical significance ( Figure 2).

Clinical parameters Mean (SD)
Age (

Discussion
The present investigation demonstrates the beneficial effects of a combined therapy, photodynamic plus nonsurgical treatment, in the improvement of periodontal indexes and in the reduction of serum inflammatory biomarkers, particularly interleukin 1β.
It is known that periodontal disease is not only a peripheral pathological condition but it is associated with several cardiovascular disorders such as endothelial dysfunction, atherosclerosis and major cardiovascular events. 5 The mechanisms of this association may be found in the widespread systemic inflammation characterizing periodontal disease. 3,4 On this basis, any treatment aimed to improve the oral health, it seems to restore the endothelium properties and reduce systemic inflammation.
In recent years the LLLT as an adjunct therapy has gained increased employment in common clinical practice and several studies have been published. [18][19][20][21][22][23] However, the results of these researches are often conflicting and various, probably due to the types of Laser and parameters of Laser radiation employed. In a case-control study, LLLT add on therapy improved not significantly oral health in terms of PD reduction, but it resulted in a significantly higher reduction in bleeding scores compared to non surgical treatment alone. 24 Moreover, in a split-mouth study Lai et al. 25  The present study has, in our opinion, some limitations. First, the small sample size. The relatively low number of participants is in part justified by the complexity of examination. Second, the study design makes not possible to discriminate the effects of the two different treatments, SRP and LLLT.

Conclusions
In conclusion, the present investigation demonstrates an improvement of periodontal disease and a concomitant reduction of some blood inflammatory markers, in patients undergoing a periodontal therapy based on Laser plus conventional therapy. This effect might be a way by which the management of periodontal disease is beneficial for a reduction of cardiovascular diseases.