Document Type : Original Article


1 Oral and Maxillofacial Surgeon and Oral Implantologist, RYA COSMO Foundation Hospital, Chennai, India.

2 Dental Surgeon, Affiliated to: RYA COSMO Foundation Hospital, Chennai, India.




Statement of the Problem: Conventional injection technique with adrenaline during removal of impacted third molar of mandible had proportionally increased pain during administration with slow onset of action and shorter duration of anesthesia.  
Purpose: The purpose of this study was to compare the effective nature of 8.4% and 7.5% buffered lidocaine hydrochloride during surgical removal of mandibular impacted third molar.
Materials and Method: This prospective crossover study included 50 patients requiring bilateral removal of impacted mandibular third molars. Group I included 50 impacted mandibular third molars that were administered with 8.4% buffered lidocaine hydrochloride and group II included 50 impacted mandibular third molars were administered with 7.5% buffered lidocaine hydrochloride. The outcome variables were pain on injection, time of onset of anesthesia, and duration of action of anesthesia. The above parameters were recorded by the investigator and statistically analyzed through Chi-square test using SPSS software.
Results: Patients in group I had mild pain (1.02) and patients in group II (5.74) had moderate pain with a statistical significance of p< 0.05 for group I respectively. The mean onset of action of anesthesia in group I was 0.08 seconds and 0.59 seconds in group II (p< 0.05). The duration of anesthesia was 342.51 minutes from group I and 122.06 minutes in group II (p< 0.05) respectively.
Conclusion: Lidocaine hydrochloride buffered with 8.4 % sodium bicarbonate was found to be more effective in reduction of pain during injection, also had a faster onset of action and longer duration of the action of anesthesia when compared to 7.5% buffered lidocaine hydrochloride.