Single Gene Polymorphism and the Success Rate of Inferior Alveolar Nerve Block

The inferior alveolar nerve block (IANB) is one of the most commonly used techniques in dentistry to achieve mandibular anesthesia during endodontic treatment. Despite its widespread use, the success rate of IANB is highly variable, with failure rates reported to range from 30% to 80% in patients with irreversible pulpitis. While several anatomical and clinical factors have been implicated, genetic variations in pain signaling pathways have been increasingly recognized as potential contributors to anesthetic failure. The SCN9A gene, which encodes the voltage-gated sodium channel Nav1.7, plays a critical role in nociception and pain modulation. The single nucleotide polymorphism (SNP) rs6746030 (G\>A) in SCN9A has been shown to alter channel function and has been associated with variable pain sensitivity and response to analgesia. This study aims to investigate the association between the SCN9A rs6746030 polymorphism and the success rate of IANB in patients undergoing root canal treatment. A total of 200 patients diagnosed with irreversible pulpitis in mandibular molars will be recruited. Based on anesthetic outcome, they will be divided into two groups: 100 patients with successful IANB and 100 patients with documented anesthetic failure. Buccal swab samples will be collected from each participant, and DNA will be extracted and genotyped using a TaqMan SNP assay. The frequency of SCN9A genotypes (GG, GA, AA) will be compared between the two groups to determine whether there is a statistically significant association with anesthetic outcome. The findings of this study will help identify genetic predictors of anesthetic failure and may provide a foundation for personalized anesthetic strategies in endodontic practice.