[Evaluation of anesthetic effect of ropivacaine in surgery of chronic periapical lessions].

INTRODUCTION Ropivacaine is used in orthopedcs, gyneacology, surgery, ophtamology, whereas experience about its usage in dentistry is still limited. The aim of this research was to compare the anesthetic effect between local anesthetics ropivacaine and bupivacaine, in surgical disposals of chronical periapical lessions in maxilla. MATERIAL AND METHODS The study included the patients that had indications for surgical removal of chronical periapical lessions at one of the frontal teeth of upper jaw. The total total number of examinees was 60, and they were devided in two groups. Ropivacaine chloride (0.75%) was used as a local anesthetic in one group (Naropin 0.75%; Astra Zeneca), and in the other one bupivacaine chloride (0.5%) (Vexelit 0.5%; Zdravlje). The authors applied 1.8 ml of block anesthesia for the n. infraorbitalis (intra-oral approach) as well as 0.2 ml of the local anesthetic from the palatine side for the final branches of N. nasopalatinus in order to observe the following anesthetic parameters. (I) Beginning of anesthesia was followed by the appearence of upper lip numbness. (II) Pain rating scale according to Sisk was used for the objective measurement of the anesthesia quality. (III) The pain intensity during the intervention was measured by visual analogous scale, on which the patient denoted the intensity of pain he had felt during the intervention. (IV) Duration of anesthetic effect--it is followed by soft tissues numbness. RESULTS AND DISCUSSION After the ropivacaine application anesthesia effect started in 1.57 min. and after the usage of bupivacaine in 1.67 min. The mean duration of soft tissue numbness after the application of ropivacaine was 321 minutes. Bupivacaine had a shorter anesthetic effect--296.5 minutes. The quality of anesthesia after the usage of ropivacaine was assessed by the surgeons with average mark--1.76. Interventions in which this anesthetic was used were performed with minimal pain and without additional anesthesia. The quality of anesthesia after the usage of bupivacaine (3.03) was statistically much worse (p < 0.01) in comparison to ropivacaine. In visual analogous scale where patients denoted the intensity of pain during the intervention with ropivacaine the marked average value was 30.1 mm while the average value with usage of bupivacaine was 41.7 mm. The patients from the control group, where bupivacaine was used, had much stronger pain, statistically significant (p < 0.05) in comparison to the group where ropivacaine was used. Our results show that the quality of anesthesia that was attained with 0.5% bupivacaine was much worse than the quality of anesthesia after the application of 0.75% ropivacaine. CONCLUSION Ropivacaine has a potential to replace bupivacaine completely in cases when there is the indication for its usage in oral surgery (longlasting intervention, interventions followed by intensive postoperational pain, nerve blockade).