Evaluation of the efficacy of Local buffered local anesthetic in Extraction of infected teeth –Randomized double blind study

Abstract

Background and Objectives: Successful pain control is an integral part of clinical practice, and anesthetising an area of interest or teeth associated with infection can be challenging. Many factors contribute to the reduction of clinical efficiency of LA, including the increased vascularity of the inflamed tissues. This reduces the local anaesthetic effect, thereby increasing the sensitivity of the tissues. It has also been reported that the pH of inflamed tissues is lowered slightly, which in turn interferes with the dissociation of local anaesthetics. Lignocaine is one of the most commonly used agents to anaesthetize an area preoperatively. It can however cause undesirable effects such as burning on injection, relatively slow onset and lack of numbness when injected into infected tissues as a result of the acidic pH of commercial preparations ( pH is between 3.5 and 7.0 compared with physiological pH, which is between 7.35 and 7.45 ). Buffered local anaesthetics can be more efficient in controlling pain is such cases. The reason for buffering local anaesthetics is substantiated by the Henderson-Hasselbalch equation; if a local anaesthetic solution is buffered to a pH that is closer to its pKa, more of the free base form will be available on injection to enter the nerve sheath. This can be achieved by the addition of sodium bicarbonate (8.4% NaHCO3), which will increase the pH of the solution. Thus the objective of this study is to compare efficacy of buffered lignocaine in extraction of infected tooth in terms of pain reduction, onset of action and burning sensation while infiltration.