Periodontitis lesions in smokers and non-smokers

Photobiomodulation increases uprighting tooth movement and modulates IL-1β expression during orthodontically bone remodeling

This study investigated the effects of photobiomodulation (PBM) in acceleration of orthodontic movement of inferior molar uprighting movement. Thirty-four individuals, with indication of molar uprighting movement for oral rehabilitation, were randomly divided in two groups: verticalization + PBM (808 nm, 100 mW, 1 J per point, 10 points and 25 J/cm2 ) or verticalization + PBM simulation. Elastomeric chain ligatures were changed every 30 days for 3 months. FBM was performed immediately, 24 h, 72 h, 1 and 2 months after activation. The primary outcome was the amount of uprighting movement. Secondary outcomes were pain, amount of medication, OHIP-14 questionnaire, and cytokine IL-1β. PBM group increase uprighting movement when compared to control after 3 months and modulate IL-1β expression. For pain control, the amount of medication and OHIP-14 no difference were found. This study suggests that PBM accelerates tooth movement during molar uprighting, due to modulation of IL-1β during bone remodeling.

The effects of smoking on genotoxic and histopathologic damage in exfoliated oral epithelial cells and the periodontium: A cross-sectional study

Smoking negatively affects the prognosis of periodontal disease by impairing tissue healing. While micronucleus is the most popular parameter for demonstrating DNA damage, inflammatory cell and vascular densities are the most evaluated parameters for determining histopathologic changes in the periodontium. This study aimed to study the effects of periodontitis and cigarette smoking on genotoxic changes in exfoliated oral epithelial cells and histopathologic changes in periodontal tissue. A cross-sectional study was conducted between November 2018 and July 2019 at a dental university hospital in Turkey, and registered as NCT05484765. Eighty systemically healthy subjects were divided into four groups according to periodontal status and smoking habits: 20 smokers with generalized periodontitis (SGP), 20 nonsmokers with generalized periodontitis (NGP), 20 smokers with healthy periodontium (SHP), and 20 nonsmokers with healthy periodontium (NHP). For each study participant, full-mouth clinical periodontal parameters (CPPs) were measured, smear samples were taken from buccal and gingival mucosa, and periodontal tissue was biopsied from the maxillary molars. Cytogenetic and histopathologic assays (primary and secondary outcomes) were conducted using Feulgen reaction and hematoxylin-eosin staining, respectively. The mean CPPs of healthy periodontium groups were lower than generalized periodontitis groups. No significant differences were found between other groups regarding CPPs. Buccal micronuclei counts in groups decreased with the highest to lowest counts occurring in the order SGP > SHP > NGP > NHP. Gingival micronuclei counts in groups decreased from SGP > SHP > NGP = NHP. The most intense inflammatory cell and vascular densities occurred in SGP and NGP groups, respectively; and the mildest values were in healthy periodontium groups. Histopathological damage score decreased significantly by group in order SGP > NGP > SHP > NHP. The synergy arising from the combination of smoking and periodontitis exposures exacerbates genotoxic and histopathologic damage in oral cells and the periodontium.

Cellular expression of epigenetic markers and oxidative stress in periodontitis lesions of smokers and non-smokers

Objective

To evaluate differences in the cellular expression of epigenetic markers and oxidative stress in periodontitis lesions between current smokers and non‐smokers.

Background

Tobacco smoking is recognized as one of the major risk factors for periodontitis. However, the mechanisms by which smoking affects the progression of the disease remain to be determined.

Methods

Twenty‐five current smokers and 21 non‐smokers with generalized severe periodontitis were included. From each patient, one soft tissue biopsy from a periodontitis site was harvested and prepared for histological analysis. The infiltrated connective tissue (ICT) was selected as the region of interest to assess the cellular expression of epigenetic markers and reactive oxygen/nitrogen species (RONS) by immunohistochemistry.

Results

Although the ICT of smokers and non‐smokers did not differ in size or in the expression of markers for DNA damage or oxidative stress, current smokers presented with significantly lower area proportions and densities of cells positive for the epigenetic markers DNMT1 and AcH3. In addition, periodontitis lesions in current smokers presented with a diminished antimicrobial activity, as indicated by significantly lower densities and area proportions of NOX2‐ and iNOS‐positive cells.

Conclusions

Components of the host response and epigenetic mechanisms in periodontitis lesions in smokers are downregulated as opposed to lesions of non‐smokers.