Anesthetic Efficacy Of An Infiltration In Mandibular Anterior Teeth Following An Inferior Alveolar Nerve Block

SCIENTIFIC REPORT

Anesthetic Efficacy of an Infiltration in Mandibular Anterior Teeth Following an Inferior Alveolar Nerve Block
Kenneth Clark, DDS, MS,* Al Reader, DDS, MS,t Mike Beck, DDS, MA,t and William J.

Meyers, DMD, MEd§
*Former graduate student in endodontics, tGraduate Endodontics, tDepartment of Oral Biology, and §Division of Endodontics, The Ohio State University, Columbus,Ohio. Dr Clark was formerly in practice limited to endodontics in Green Bay, Wisconsin.

The purpose of this prospective, randomized, blinded study was to measure the degree of pulpal anesthesia obtained with an inferior alveolar nerve (IAN) block followed by an infiltration in mandibular anterior teeth. Through use of a repeated-measures design, 40 patients randomly received 3 injectioncombinations at 3 separate appointments: an IAN block followed by a mock lingual infiltration and a mock labial infiltration, an IAN block followed by a mock lingual infiltration and a labial infiltration, and an IAN block followed by a mock labial infiltration and a lingual infiltration. Each IAN block used 3.6 mL of 2% lidocaine with 1:100,000 epinephrine, and each infiltration used 1.8 mL of 2%lidocaine with 1:100,000 epinephrine administered over the lateral incisor apex. Mandibular anterior teeth were blindly pulp tested at 2minute cycles for 60 minutes following the IAN-infiltration injections. No response from the patient to the maximum output (80 reading) of the pulp tester was used as the criterion for pulpal anesthesia. Anesthesia was considered successful when 2 consecutive 80 readingswere obtained within 15 minutes and the 80 reading was sustained for 60 minutes. Anesthesia was considered a failure if 2 consecutive 80 readings were not obtained during the 60 minutes. The results of this study showed that 100% of the patients had lip numbness with all IAN blocks. For the lateral incisor, the success rate of the IAN block alone was 40% and the failure rate was 30%. For the IANblock plus labial infiltration, the success rate was 62% and the failure rate was 12% for the lateral incisor. There was a significant difference (P < .05) between the IAN block alone and the IAN block plus labial infiltration. In conclusion, a labial infiltration, over the lateral incisor apex, of 1.8 mL of 2% lidocaine with 1:100,000 epinephrine following an IAN block significantly improvedpulpal anesthesia for the lateral incisor compared with the IAN block alone.

Key Words: Local anesthesia; Inferior alveolar nerve block; Infiltration; Lidocaine;
Mandibular anterior teeth.

he inferior alveolar nerve (IAN) block is the most frequently used mandibular injection technique for achieving local anesthesia for restorative and surgical
Received October 3, 2001; accepted for publicationMarch 1, 2002. Address correspondence to Al Reader, DDS, MS, Graduate Endodontics, Box 182357, College of Dentistry, The Ohio State University, 305 W 12th Ave, Columbus, OH 43218-2357; reader.2@osu. edu. Anesth Prog 49:49-55 2002 © 2002 by the American Dental Society of Anesthesiology

procedures. However, the IAN block does not always result in successful pulpal anesthesia. 1-2 Failure ratesin anterior teeth have ranged from 10°/-90%.1-' For IAN blocks, the theory of cross-innervation has been cited as the reason why achieving pulpal anesthesia in mandibular anterior teeth is so difficult.10"2 By administering bilateral IAN blocks, Rood' demonstrated that the nerve supply to the pulps of the central incisors were bilaterally innervated. Yonchak et al'2 also adminISSN0003-3006/02/$9.50 SSDI 0003-3006(02)

49

50

Anterior Infiltrations Following an Inferior Alveolar Nerve Block

Anesth Prog 49:49-55 2002

istered bilateral IAN blocks and found that cross-innervation seems to occur in mandibular central and lateral incisors. However, the success rate (no response to pulp testing) in the lateral and central incisors with bilateral IAN blocks was below 75%. The...