Effect of Smoking on Periodontal Health – An In vitro Study Investigating the Role of a Confounding Factor

Abstract Background: The periodontal ligament (PDL) is essential in maintaining tooth stability, absorbing masticatory forces, and supplying nutrition to the root surface. Its health is influenced by lifestyle and systemic factors, such as smoking, which has been linked to PDL deterioration. This present study aimed to examine the residual periodontal ligament (RPL) on extracted teeth from chronic periodontitis patients, comparing smokers and nonsmokers to evaluate the effect of smoking on PDL health. Materials and Methods: The study included the extraction and analysis of 50 teeth from two groups: smokers and nonsmokers with chronic periodontitis. Teeth were stained with hematoxylin to measure RPL levels from the root apex using a digital Vernier caliper, and statistical analysis was conducted using SPSS software to determine the significance between the groups. Smoking intensity was quantified in pack-years to explore the correlation between smoking habits and PDL deterioration. Results: The study found that smokers exhibited significantly lower RPL values compared to nonsmokers ( P < 0.05), especially in incisor and premolar areas, suggesting a negative impact of smoking on periodontal health. Although a trend of increased RPL damage with higher pack-years was observed, these differences were not statistically significant. In addition, confidence intervals overlapped, indicating that increased smoking duration did not consistently correlate with greater PDL damage. Conclusion: Smoking produces detrimental effects on PDL health, particularly in specific dental areas; however, the study found an imperceptible association between smoking intensity and RPL levels.