RESUMO
BACKGROUND: The extraction of tooth being the most common procedure in oral surgery should be pain free with limited dosage and limited needlepricks. Articaine being unique among amide local anesthetics contains a thiophene group, which increases its liposolubility, and an ester group which helps biotransformation in plasma. Because of the high diffusion properties, it can be used as a single buccal infiltration to extract a maxillary tooth. AIM AND OBJECTIVE: Objective of the study was to compare the efficacy of single buccal infiltration of 4% articaine with that of 2% lignocaine for maxillary first molar extraction. METHODOLOGY: A triple blind randomized controlled study was carried on 100 patients of age group 18-60 years who required maxillary first molar extraction, visiting the Department of Oral and Maxillofacial surgery. They were included in the study after obtaining informed consent. Buccal infiltration of 1.8 ml of anesthetic solution was given randomly to 100 patients with appropriate blinding of the cartridges. Objective signs were checked. If any additional injection was given, it was noted as type and number of rescue injection given. Postoperatively VAS score and surgeon's quality of anesthesia was noted. Duration of anesthesia was measured every 5 minutes for 50 minutes from infiltration. RESULTS: Out of 50 patients in group A (Articaine), in 44 patients extraction was done without the need of additional injection whereas in group B(Lignocaine), 29 patients require additional infiltration on the palatal side. The VAS score values for group A were also significantly less in comparison with group B. The mean duration of anesthesia for Group A being (71.70 ± 17.82 min) in 44 patients who only received buccal infiltration. INTERPRETATION AND CONCLUSION: The efficacy of single buccal injection of articaine is comparable to buccal and palatal injection of lignocaine.
RESUMO
pH and salts have a marked effect on the stability, structure, and function of many globular proteins due to their ability to influence the electrostatic interactions. In this work, calorimetry, CD, and fluorescence studies have been carried out to understand the pH-dependent conformational changes of the two-domain protein yeast hexokinase A. In conjunction with the crystal structural data available, the present results have enabled the complete characterization and analysis of the pH-dependent conformational changes of the enzyme that have strong implications in understanding its structure-function relationship. The calorimetric profiles show a single thermal transition in the acidic pH range, whereas two independent transitions were observed in the alkaline pH range, suggesting the structural merger of the domains at the acidic pH. Comparison of the thermal transitions at pH 8.5 studied by different techniques suggests that the first transition corresponds to the smaller domain, and the second transition corresponds to the larger domain. The acid-denatured state of hexokinase A has high secondary structure content with little or no tertiary interactions and binds to the hydrophobic dye 8-anilinonaphthalene-1-sulfonic acid, suggesting that it is a molten globule-like state, whereas the alkali-denatured state is less structured than the acid-denatured state but more structured than the urea-denatured state, suggestive of a premolten globule-like state. Structural analysis using the published hexokinase B structure as well as the hexokinase A structure with the revised amino acid sequence in conjunction with the results obtained by us suggests that the ionization state of the acidic residues at the active site could regulate domain movements that are responsible for the opening and the closure of the cleft between the two domains and in turn affect the structure and function of the enzyme.
