RESUMO
OBJECTIVES: The aim of this study was to determine the effect of intraosseous (IO) anesthesia with 4% articaine and 1:100,000 epinephrine on pulpal blood flow (PBF) and pulpal anesthesia of mandibular first molars and canines in human subjects. MATERIALS AND METHODS: Ten healthy volunteers with intact mandibular first molar and canine were given an osteocentral technique of IO injection using the Quick Sleeper 5 system and 4% articaine with 1:100,000 epinephrine at distal site of mandibular first molar. The PBF was monitored by a laser Doppler flowmeter (LDF). Pulpal anesthesia was assessed with an electric pulp tester (EPT). RESULTS: IO injection caused a decrease in PBF in molars from 6.31 ± 3.85 perfusion units (P.U.) before injection to 2.51 ± 2.53 P.U. 1 min after injection (P < 0.001). The percentage reduction in PBF was 60% after 1 min and PBF returned back to the baseline after 45 min. No significant reduction in PBF was observed in the canines (P = 0.212). For pulpal anesthesia in the molars, the mean onset was 2.40 ± 0.84 min and the mean duration was 38 ± 16.19 min. In the canines, there was a decrease in the sensitivity to EPT but complete pulpal anesthesia was not achieved. CONCLUSIONS: IO injection distal to mandibular first molar caused a decrease in PBF and successful pulpal anesthesia in first molar, but not in canine. Both PBF and EPT readings returned to normal, suggesting that pulpal ischemia may not occur. CLINICAL RELEVANCE: IO anesthesia is safe to use as a primary technique in teeth with normal pulp.