Background: An essential pre- requiste to success in dentistry is to achieve good quality local anesthesia. Local anesthesia forms the backbone of pain control technique in dentistry & there has been substantial research interest in finding safe & more effective technique for maxillary 1st molar.

Aim& objective: The purpose of this prospective, randomized, single-blind crossover study was to evaluate the anesthetic efficacy of a combination of buccal and buccal plus palatal infiltration of the maxillary first molar.

Materials and Methods: In a crossover study, 42 participants received two maxillary first molar injections at separate appointments spaced by at least a week. Each side of the mouth acted as either the experimental or control group. The anesthetic used was 2% lidocaine with 1:80,000 epinephrine.One injection set consisted of a buccal infiltration of 1 mL of 2% lidocaine with 1:80,000 epinephrine followed by a palatal infiltration of 0.5 mL of the same anesthetic two minutes later. The other set involved a 1 mL buccal infiltration of 2% lidocaine with 1:80,000 epinephrine followed by a sham palatal infiltration, where only the needle pierced the palatal tissue. The first molar was tested for pulp sensation using an electric pulp tester five minutes after the final injection. The testing continued at two-minute intervals for ten minutes, reaching a maximum of 80 readings. Anesthetic success was defined as the absence of a response to two consecutive readings of 80 on the electric pulp tester. If a participant did not achieve anesthesia within ten minutes, they were excluded from the study. The depth of anesthesia was monitored throughout using the electric pulp tester. Pulp test readings were also taken on the buccal and lingual surfaces of the first molar five minutes after the final injection.

Results: The success rates were 78.6% for the buccal infiltration and 92.8% for the buccal plus palatal infiltration. The difference was not statistically significant. The buccal plus palatal infiltration significantly increased the incidence of pulpal anesthesia from 21 minutes through 57 minutes. Although there was an increased incidence of pulpal anesthesia with the combination buccal plus palatal infiltration, anesthesia was not provided for 60 minutes.

Conclusions In conclusion, adding palatal infiltration of 0.5ml of 2% lignocaine with 1:80,000 epinephrine with the buccal infiltration did not significantly increase the anesthetic success in maxillary first molar.