About this trial
Voltage-gated sodium channels, especially Nav1.7 encoded by the SCN9A gene, are key regulators of nociceptive transmission. Upregulation of SCN9A has been associated with increased neuronal excitability and heightened pain perception. In parallel, inflammatory cytokines such as interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), and interleukin-1 beta (IL-1β) are known to sensitize peripheral nociceptors and reduce the efficacy of local anesthetics by modifying tissue environment and ion channel activity. However, the combined influence of SCN9A expression and inflammatory cytokines on anesthetic success in SIP has not been fully elucidated.
This prospective case-control study aims to evaluate the association between SCN9A gene expression and inflammatory cytokine levels with the clinical success of IANB in patients with SIP affecting mandibular molars. Approximately 90-100 patients will be recruited and categorized into two groups based on anesthetic outcome: successful anesthesia and failed anesthesia. All patients will receive a standardized IANB using 2% lidocaine with 1:100,000 epinephrine. Anesthetic success will be determined based on the absence of pain during access cavity preparation and instrumentation.
Following access and pulp extirpation, pulpal tissue samples will be collected. SCN9A gene expression will be assessed using quantitative real-time polymerase chain reaction (RT-qPCR), with relative expression calculated using the 2\^-ΔΔCt method. Inflammatory cytokine levels (IL-6, TNF-α, IL-1β) will be quantified using enzyme-linked immunosorbent assay (ELISA).
The primary outcome will be the difference in SCN9A expression between failed and successful anesthesia groups. Secondary outcomes will include comparison of cytokine levels and evaluation of correlations between SCN9A expression and inflammatory markers. Statistical analysis will include group comparisons, correlation analysis, logistic regression, and receiver operating characteristic (ROC) curve analysis to assess the predictive value of these biomarkers.
Eligibility criteria
This trial accepts healthy volunteersQualifiers
Patients aged 18-60 years
Systemically healthy individuals (ASA I or II)
Presence of a mandibular first or second molar diagnosed with symptomatic irreversible pulpitis
Vital tooth confirmed by positive response to pulp sensibility tests (cold test/EPT)
Disqualifiers
Patients who have taken analgesics, anti-inflammatory drugs, or antibiotics within the last 48 hours
Presence of systemic diseases affecting pain perception or inflammation (e.g., diabetes, neuropathic disorders)
Pregnant or lactating women
Teeth with periapical abscess, swelling, or sinus tract
Trial population
The study population will consist of adult patients presenting to the postgraduate endodontic clinic with symptomatic irreversible pulpitis in mandibular first or second molars requiring root canal treatment. Eligible participants will be systemically healthy (ASA I or II), aged between 18 and 60 years, and will report moderate to severe preoperative pain. Diagnosis will be established based on clinical findings, including spontaneous pain, prolonged response to cold testing, and absence of periapical pathology requiring surgical intervention.
Trial design
Case-control
Prospective
Treatments tested in this trial
Inferior Alveolar Nerve Block
Procedure/SurgeryAll participants will receive a standardized inferior alveolar nerve block (IANB) administered using 2% lidocaine with 1:80,000 epinephrine. The injection will be performed using a conventional Halsted technique with a 27-gauge long needle under strict aseptic conditions. The needle will be inserted at the pterygomandibular raphe region, advancing until bony contact is achieved near the mandibular foramen. Following negative aspiration, approximately 1.8 mL of anesthetic solution will be deposited slowly over 60-90 seconds. Lip numbness will be assessed after 10-15 minutes to confirm nerve block onset. No additional anesthetic techniques will be used prior to the assessment of primary anesthetic success. Endodontic access cavity preparation will then be initiated, and pain response during access and initial instrumentation will be recorded using a standardized pain scale. Anesthetic success or failure will be determined based on the patient's pain response, as per predefined criteria.
Treatment groups
Trial outcomes
Primary outcomes
Success of Inferior Alveolar Nerve Block (IANB)
The primary outcome will be the clinical success of the inferior alveolar nerve block (IANB), assessed during endodontic access cavity preparation and initial instrumentation. Anesthetic success will be defined as the absence of pain or the presence of only mild pain that does not require any supplementary anesthetic intervention. Anesthetic failure will be defined as the presence of moderate to severe pain necessitating additional anesthesia (e.g., intraligamentary or intrapulpal injection).
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