Kovanaze Intranasal Spray vs Traditional Injected Anesthetics: a Study of Pulpal Blood Flow Utilizing Laser Doppler Flowmetry

Objective: An ideal local anesthetic would be effective, minimally reduce pulpal blood flow (PBF), and not require injection. This study compared the effects of 3% tetracaine plus 0.05% oxymetazoline nasal spray (Kovanaze; KNS) and injections using 2% lidocaine with 1:100,000 epinephrine (LE) or 3% mepivacaine plain (MP) on PBF, anesthetic efficacy, and participant preference. Methods: In a double-blind cross-over design, 20 subjects randomly received a test anesthetic and placebo at each of 3 visits (KNS/mock infiltration; mock nasal spray/LE; or mock nasal spray/MP). Nasal sprays and infiltration apical to a maxillary central incisor were delivered ipsilaterally. PBF was evaluated by laser Doppler flowmetry, and local anesthetic success was assessed with electric pulp testing. Postoperative pain levels, participant preference, and adverse events were also assessed. Results: LE injections demonstrated significant reductions in PBF at all time intervals compared with baseline (P < .05), whereas KNS and MP did not. Pulpal anesthesia success rates were higher for LE (85%) compared with MP (35%) and KNS (5%). Participants reported significantly higher postoperative pain levels for KNS compared with LE and MP. Additionally, KNS was the least preferred of the anesthetics administered and resulted in more reported adverse events. Conclusion: Although KNS showed no significant effect on PBF, it was not effective in achieving pulpal anesthesia as used in this study.