ANESTHETIC EFFICACY OF THE PERIODONTAL-LIGAMENT INJECTION AFTER AN INFERIOR ALVEOLAR NERVE BLOCK

The purpose of this study was to determine the contribution of the per iodontal ligament injection (PDL) to the inferior aveolar nerve (IAN) block in human first molars. Using a repeated-measures design, 40 subj ects randomly received a combination IAN block and PDL injections of t he first molar using 2% lidocaine with 1:100,000 epinephrine and a com bination IAN block and mock PDL injections (needle penetration only) a t two successive appointments. The first molar and adjacent teeth, and contralateral canine (positive and negative controls) were blindly te sted with an Analytic Technology pulp tester at 2-min cycles for 60 mi n. Profound anesthesia was defined as no subject response at an 80 rea ding. One hundred percent of the subjects had lip numbness with the IA N block. When the combination IAN/PDL injections were compared with th e IAN block, the incidence of successful pulpal anesthesia (80 reading ) was significantly greater for the combination injections through the first 23 min of pulp testing. However, after 23 min, there was no inc rease in anesthetic success by adding the PDL to the IAN injection. We concluded that adding the PDL injection to an IAN block increased the incidence of pulpal anesthesia for the first 23 min in the first mola r.