Establishment of a Quantitative Method for the Extraction of Nicotine and Cotinine in Gingival Tissue and Relationship Between Gingival Intoxication With Conventional Smoking Biomarkers: A Pilot Study.

OBJECTIVES

Smoking is considered a major risk factor for periodontitis genesis and progression. In clinical studies, specific indicators have been used to characterize the smoking status of the patient as the number of cigarettes consumed (NCC), the pack-years (PY), or Fagerström Test for Nicotine Dependence (FTND). However, available literature is missing on the relationship between cotinine gingival intoxication and smoking indicators. First, the development of a quantitative method for the extraction of nicotine and cotinine in gingival tissue. Second, to investigate the relationship between gingival intoxication and conventional smoking biomarkers.

MATERIAL AND METHODS

Fourteen smoker patients were included in the study. After clinical data collection, salivary and gingival samples collection, toxicological analyses were performed using liquid extraction after enzymatic digestion (subtilisin) and ultra-performance liquid chromatography coupled to mass spectrometry (UPLC-MS/MS).

RESULTS

Gingival cotinine quantification was successfully performed in 14 samples (100%) with a mean of 0.280 ng/mg (range = 0.094-0.505). Only FTND was statistically associated with gingival cotinine levels (p = 0.0072; r² = 0.60). Gingival nicotine quantification was achieved in 12 of the 14 gingival samples (86%) with a mean of 0.384 ± 1.00 ng/mg (range = 0.03-3.84). Gingival nicotine was statistically associated with NCC (p = 0.032; r² = 0.55), PY (p = 0.0011; r² = 0.76), and FTND (p = 0.016; r² = 0.60). Salivary nicotine and cotinine levels were statistically associated with, respectively, NCC (p = 0.030; r² = 0.34), and NCC (p = 0.0094; r² = 0.63) + PY (p = 0.0078; r² = 0.64).

CONCLUSIONS

This pilot study established a quantitative extraction method for nicotine and cotinine from human gingival samples. Additionally, FTND was associated with gingival cotinine. However, further large-scale studies are needed to confirm the relationship between nicotine dependence and gingival intoxication.