The effect of mucosal cooling and topical anesthesia application on pain perception during infiltration injection and latency time of anesthesia for maxillary central incisors

Infiltration injections for maxillary central incisors at the labial site is considered to be one of the most painful injection sites in the mouth. Different strategies are being used to avoid the pain associated with the needle prick but none has proven to be the answer to the problem. The purpose of the present study is twofold: (a) to evaluate the effect of local cooling on the pain perceived during needle penetration and anesthetic injection of local anesthesia in patients, and (b) to assess the time elapsed between the injection and no response to pulp testing. In a crossover double-blind clinical trial, 30 dental students participate. Inclusion criteria include healthy patients with intact central incisors and the ability to understand the use of pain scales. Using any type of analgesics, sedative, or antianxiety medications during 48 h before the study and allergy to lidocaine are the exclusion criteria. Participants will be randomly allocated to receive an infiltration injection with application of topical anesthesia, precooling with refrigerant spray or without anything. Immediately after the injection of 1.8 ml of lidocaine with 1:80,000 epinephrine, the volunteers will be asked to rate their pain level during needle penetration and during anesthetic solution. The responses of the tooth to electric pulp testing will be recorded every 2 minutes till no response to the test. The dentist will be responsible for administering anesthesia the attending nurse will ask the participants to score the level of pain. The nurse and statistic analyzer remains unaware of the groups.

Kerman University of Medical Sciences