Comparative Evaluation of Effects of Additives to 2% Lignocaine for Surgical Extraction of Impacted Mandibular Third Molars: A Randomized Controlled Clinical Study

Abstract

Adrenaline bitartrate is the most common vasoconstrictor used to counteract the vasodilatory properties of amide local anesthetics. Use of adrenaline has certain contraindications and disadvantages specially in patients with cardiovascular diseases. It is evident from the literature that there are conflicting opinions about usage of adrenaline with local anesthetics in dental procedures. Use of many drugs as additives to local anesthetics has been well documented for regional and spinal nerve blocks in the medical literature. However, there is dearth of such studies in dentistry and till date, Lignocaine hydrochloride with Adrenaline bitartrate is considered as the standard solution for local anesthesia for oro-facial procedures. Surgical extractions of impacted mandibular third molars, the most common surgical procedure in Oral and Maxillofacial surgery practice, have been used as a model for various comparative studies related to administration and evaluation of antibiotics, analgesics, steroids, use of surgical techniques, drains, suture materials etc This double blind randomized controlled clinical study was thus designed to comparatively evaluate effectiveness of Clonidine hydrochloride, Potassium chloride, Dexamethasone sodium phosphate and Chlorpheniramine maleate Vs Adrenaline bitartrate, used as additives to 2% lignocaine hydrochloride for surgical extractions of impacted mandibular third molars in healthy young adults. The evaluation was based on onset, duration, depth of anesthesia, post-operative pain control, bleeding control and changes in hemodynamics. A statistically significant difference was obtained for inter group comparison with Kruskall Wallis ANOVA for all variables used. Mann Whitney test using pair-wise comparison showed the effect of each drug pair. It was observed that number of injections used were maximum for CPM and plain Lig grp and least for Dexa and KCl grps. The onset was fastest with KCl and slowest for CPM grp. The duration of action was maximum for Dexa and least for plain Lig grp. Intra-operative pain control was best with Dexa and least with CPM grp, whereas, post-operative pain control was best with CPM and least with plain Lig grp. Bleeding control was best with Adr and least

with plain Lig grp. Hemodynamic stability was best seen in Dexa and Clonidine grps and least with Adr. Thus, none of the drugs used as a substitute fo adrenaline has completely served the purpose, however, based on the statistical results, Dexamethasone and Clonidine are still comparable to Adr for most variables with an added advantage of better stability in hemodynamic variables. Further studies focusing on pH of the mixtures, shelf life of the solutions, comparison of drug plasma levels, usage in medically compromised pts, with other oro-facial block techniques, may be planned.