Discomfort of infiltration and intraligamentary injections for mandibular central incisors

Objectives: This study assessed the discomfort associated with injections in the lower central incisor region in adults. Methods: Following receipt of ethical approval 12 healthy volunteers aged 20 - 24 years attended on 3 separate visits at least one week apart. In a randomized order they received either an intraligamentary injection of 0.18ml on the mesio-buccal aspect of a lower central incisor, a buccal infiltration of 1.0ml or a lingual infiltration of 1.0ml in the lower central incisor region. After the three visits each volunteer had received each type of injection. The anesthetic used on each occasion was 2% lidocaine with 1:80,000 epinephrine. Immediately after each injection the volunteers assessed the discomfort of injection on a 100mm visual analogue scale (VAS) with end points "no pain" and "unbearable pain". Data were analysed by ANOVA and paired t tests; p values < 0.05 were considered significant. Results: The injections varied in the amount of discomfort produced (F=3.74; p=0.034). The mean (+ one standard deviation) VAS score for intraligamentary injections was 28+12mm, for buccal infiltrations 17+8mm and for lingual infiltrations 16+16mm. Intraligamentary injections were more uncomfortable than both buccal infiltrations (t=3.7; p=0.003) and lingual infiltrations (t=2.67; p=0.02).The infiltration techniques did not differ in the discomfort they produced (t=0.27 p=0.8). Conclusions: Intraligamentary injections are more uncomfortable than infiltration anesthesia in the lower central incisor region in adult volunteers. Buccal and lingual infiltrations in this region produce similar discomfort.