A clinical audit into the success rate of inferior alveolar nerve block analgesia in general dental practice.

AIMS AND OBJECTIVES: The aim of this study was to produce some observational evidence of the success rate of inferior alveolar nerve block (IDB) analgesia that is achieved in general dental practice. The objective was to help provide some measure of expected failure rates and help dental practitioners in their self-appraisal of this crucial basic skill. METHOD: Up to 100 consecutive IDB analgesia procedures for four dentists were recorded. In a subdivision of this study 200 consecutive IDBs for a fifth dentist were recorded. This dentist had the greatest experience of giving IDB analgesia of the dentists in this study. In this part of the study the dentist made a note if he anticipated that the procedure would fail. The reason for this was that it was felt that experienced dental practitioners could predict when failure was about to occur. The level of facial nerve palsy was also recorded. RESULTS: Overall, 533 of 580 (91.9%) local anaesthetic administrations were deemed to be successful. The only factor that significantly affected the likelihood of success was the practitioner administering the local anaesthetic, and this was only borderline statistically significant. In order to be certain that the other factors did not affect the outcome, the data were re-analysed using the technique of Poisson regression. This technique investigated the effects of each of the factors in turn while controlling for the differences in success that can be attributed to the different practitioners. The regression analyses also did not detect any differences in success that could be attributed to any of the other recorded factors. The incidence of facial palsy was 0.3%. CONCLUSION: This paper gives an insight into the possible success rates to be encountered by general dental practitioners when they administer IDB analgesia. The only recorded factor that could be shown to affect the chance of a successful local analgesic was the operator. The incidence of facial nerve palsy at 0.3% may be more common than has previously been considered.