A clinical comparison between maxillary and mandibular posterior teeth using local anesthesia and normal saline by the periodontal ligament injection : an in vivo study

Background : local anesthesia is the primary method used in dentistry to control patients’ pain. However, even in the presence of adequate soft tissue anesthesia, there may be incomplete pulpal anesthesia. This is particularly true in the mandible where obtaining profound pulpal anesthesia may be difficult. The periodontal ligament injection has received much attention in the dental literatures. lntraligamentary anesthesia has been advocated as a primary and a supplemental injection technique. The purpose of this study is to evaluate, with electrical pulp tester, the anesthetic efficacy of the periodontal ligament injection using 2 % Lidocaine with 1:80000 epinephrine and normal saline in forty volunteers. The success rate was defined as no patient’s response to the maximum output of an electrical pulp tester. Also pain rating during initial needle penetration and injection of solution were compared. Material and method : Forty adult volunteers participated in this study. The subjects were divided into four groups (10 subjects each): Group Ia: each subject received a periodontal ligament injection in mandibular first premolar and first molar right or left side with Lidocaine injection and pulp tested each minute by EPT and Ethyl chloride. Group 1b : each subject received a periodontal ligament injection in mandibular first premolar and first molar right or left side with normal saline injection and pulp tested each minute by EPT and Ethyl chloride. Group IIa : each subject received a periodontal ligament injection in maxillary first premolar and first molar right or left side with Lidocaine injection and pulp tested each minute by EPT and Ethyl chloride. Group IIb: each subject received a periodontal ligament injection in maxillary first premolar and first molar right or left side with normal saline injection and pulp tested each minute by EPT and Ethyl chloride. Results : the results showed that the duration of profound pulpal anesthesia, using 2 % Lidocaine with 1: 80000 epinephrine, was 10 minutes and injection of anesthetic solution and normal saline in clinically healthy teeth were only mildly discomforting. The periodontal ligament injection using normal saline was not effective in producing anesthesia. A conclusion was drawn from the study that the periodontal ligament injection can be used effectively, as a primary injection technique, to anesthetize mandibular posterior teeth especially the first molars.