CLINICAL RESEARCH Evaluation of Receptor Activator of Nuclear Factor Kappa B Ligand, Osteoprotegerin, Osteopontin, and Tumor Necrosis Factor Alpha on Chronic Apical Periodontitis in Smokers

Introduction: Smoking can be considered a risk factor for chronic apical periodontitis (CAP). This study compared the immunoexpression of biomarkers receptor activator of nuclear factor kappa B ligand (RANKL), osteoprotegerin (OPG), osteopontin (OPN), and tumor necrosis factor alpha (TNF-a) in CAP in smokers and nonsmokers. Methods: Twelve smokers and 12 nonsmokers diagnosed with CAP and indicated for tooth extraction were selected. Exclusion factors were teeth with a diagnosis of root fracture, previous endodontic treatment, or endoperiodontal injury, in addition to individuals with systemic diseases, under 18 years of age, users of anti-inflammatory and/or antibiotics in the last 3 months, and drug users. Specimens were processed for histopathologic and immunohistochemical analysis. Results: Qualitative analysis of RANKL expression showed 66.66% weak/moderate and 33.33% strong in smokers and 100% weak/moderate in nonsmokers. OPG and OPN expressions were 100% negative to focal in the smoker group and 50% negative to focal and 50% weak/moderate in the nonsmoker group. TNF-a was 25% negative to focal and 75% weak/moderate in the smoker group and 33.33% negative to focal and 66.66% weak/ moderate in the nonsmoker group. Quantitative analysis of the data using the Mann-Whitney U test showed that there was a significant difference in the immunoexpression of RANKL (P < .05), OPG (P < .05), and OPN (P < .05), but there was no statistical difference in the immunoexpression of TNF-a (P . .05) between the 2 groups. Conclusions: These findings suggest that smoking is capable of altering the inflammatory response, influencing the evolution of CAP.

Automated summary

This study compared the immunoexpression of biomarkers RANKL, OPG, OPN, and TNF-a in smokers and nonsmokers with chronic apical periodontitis (CAP). The results showed significant differences in the expression of RANKL, OPG, OPN, and TNF-a between smokers and nonsmokers.