Lidocaine 200mg/10ml (2%) / Adrenaline (base) 50micrograms/10ml (1 in 200,000) solution for injection ampoules

ObjectiveThis meta-analysis assessed the efficacy of various anesthetic protocols for symptomatic irreversible pulpitis, comparing techniques and agents to identify the optimal anesthesia approach.MethodsWe conducted a comprehensive search of the Cochrane Library, PubMed, Web of Science, Scopus, and Embase databases up to July 10, 2025, identifying relevant studies based on predefined inclusion and exclusion criteria. The primary outcome was the success rate of anesthesia. Data extraction and quality assessment were performed using a pre-designed form and the revised Cochrane Risk of Bias Tool. A fixed-effect model was used for meta-analysis when heterogeneity was low (I 2 ≤ 50%, p ≥ 0.1); otherwise, a random-effects model was adopted. Additionally, another model was employed for validation, and the results from both models were compared to derive more reasonable conclusions. Publication bias was assessed using funnel plots and the Egger test.ResultsFourteen RCTs were included in the meta-analysis. Pooled analysis showed that modified anesthetic protocols for SIP were 3.62 times more successful than conventional inferior alveolar nerve block (IANB) using standard 2% lidocaine with epinephrine (OR = 3.34; 95% CI: 2.49-4.48). Studies conducted in Iran had the highest success rate (OR = 4.31; 95% CI: 3.59-5.17, p p p ConclusionThis meta-analysis assessed the efficacy of various anesthetic protocols for SIP, comparing techniques and agents to identify the optimal anesthesia approach.Systematic review registrationhttps://www.crd.york.ac.uk/PROSPERO/recorddashboard, PROSPERO database CRD42025638427.

Abstract licence: CC BY

Background/Objectives: Local anaesthetic systemic toxicity (LAST) is a rare but potentially fatal complication of dental and oral and maxillofacial surgical local anaesthesia (LA). Three amide agents are commonly used in the UK: lignocaine (lidocaine) 2% with adrenaline 1:80,000; articaine 4% with adrenaline 1:100,000 (2.2 mL cartridges); and bupivacaine 0.5%. Clinically significant discrepancies between guideline sources for maximum recommended dosages (MRDs) persist, and the additive toxicity of combined amide agents remains underappreciated. The objectives are: to provide clear, evidence-appraised MRD guidance for dental practitioners; to explain safe combination dosing using the fractional dose rule with acknowledgement of its pharmacokinetic limitations; and to outline recognition and management of LAST, including intravenous lipid emulsion (ILE) therapy, setting-stratified response, and differential diagnosis. Methods: These include the following: narrative review of MEDLINE (via PubMed), the Cochrane Library, and Embase (inception to May 2026), supplemented by key regulatory documents (British National Formulary (BNF) 91; US Food and Drug Administration (FDA) prescribing information; UK Summaries of Product Characteristics (SmPCs)); major guideline documents (American Society of Regional Anesthesia and Pain Medicine (ASRA) 2018; Association of Anaesthetists 2021; Resuscitation Council UK 2021); systematic reviews; and peer-reviewed literature, ranked by a jurisdiction-specific UK prescribing and regulatory source hierarchy. Results: BNF 91 and the FDA both support a 7 mg/kg (500 mg) MRD for lignocaine with adrenaline; in practice, the adrenaline ceiling limits administration to 6-7 cartridges (2.2 mL) regardless of the guideline followed. The principal reasons for caution when combining amide agents are; additive systemic toxicity, more complex dose calculation, absence of proven clinical benefit for concurrent mixing, unnecessary drug exposure, and incremental hypersensitivity risk-not metabolic pathway differences. The fractional dose rule is a pharmacologically justified safety heuristic with acknowledged pharmacokinetic limitations. ILE is a specific rescue therapy for severe or cardiovascular LAST; airway support and oxygenation remain the primary interventions. Patient-specific factors substantially lower the effective toxic threshold. Conclusions: Safe LA administration in oral surgery requires systematic MRD calculation, application of the fractional dose rule for combined-agent appointments, attention to patient-specific risk factors, setting-appropriate emergency preparedness, and structured differential diagnosis to distinguish LAST from more common dental emergencies.

Abstract licence: CC BY