A clinical study on the effect of injection sites on efficacy of anesthesia and pulpal blood flow in carious teeth

Abstract

This randomized clinical trial evaluated the efficiency of maxillary infiltration anesthesia in carious teeth at two different injection sites and their impact on the laser Doppler recordings of pulpal blood flow (PBF) during a caries excavation procedure. The null hypothesis tested was that there are no differences in the efficiency of anesthesia and PBF reduction between maxillary infiltrations at the two injection sites. One hundred twenty patients were divided into three groups according to the degree of carious lesion of their maxillary left central incisors (moderate caries, deep caries, or no caries). Forty patients in each group randomly received infiltrations over the root apex of maxillary left central incisors (site X) or over the midpoint of the line connecting the root apexes of both maxillary left central and lateral incisors (site Y) using 0.9 mL 2% lidocaine with 1:100,000 adrenaline. Teeth were pulp tested at five-minute intervals after injection except for the period of cavity cutting, which was done 12 minutes after injection. The PBF changes after injection were monitored by laser Doppler flowmetry. The observation period in this study was 60 minutes. Success of anesthesia was defined as no or mild pain on cavity cutting by visual.