Effectiveness of Pre Injection Use of Cryoanesthesia as Compared to Topical Anesthetic Gel in Reducing Pain Perception During Palatal Injections

The goal of this interventional study is to assess the effectiveness of pre-injection use of topical ice application in decreasing pain perception when administering greater palatine nerve block injections as compared to that of topical 20 % benzocaine anesthetic gel using Visual Analogue Scale (VAS) for subjective pain assessment and Sound, Eye, Motor (SEM) scale for objective pain assessment in adult patients.

The main question it aims to answer are:

1. Does topical cooling reduce pain as effectively as topical benzocaine during greater palatine nerve block injections?
2. Is there any adverse reactions during and after application of topical ice and 20 % benzocaine gel?
3. Is there any difference in patient acceptability to the use of either methods during the administration of greater palatine nerve block.

A split mouth design was used where an anesthetic injection was administered in the left and right posterior palatal area. The same operator administered the injections so as to standardize the flow rate and delivery style. The method of intervention i.e topical ice or topical 20% benzocaine anesthetic gel was randomly allocated to the patient by lottery method. The participants received two palatal injections with an interval of two weeks between the appointments. The subjective pain response of the patients during greater palatine nerve block injection with pre-injection use of topical ice and topical anesthetic gel (20% benzocaine) was recorded using VAS scale. The objective pain response of the patients were recorded by a blinded single observer using SEM scale on the same day of the appointment.

Technique of application of topical ice: A new pack of sterile cotton swabstick that was injected with 0.5ml commercially available bottled water and then freezed the day before the appointment. At the time of intervention the injection site was dried with gauge piece and the frozen cotton swab stick was held by its wooden part and the frozen cotton end was placed on the proposed anesthetic site (palatal mucosa just anterior to the greater palatine foramen) for 1 minute. With the frozen cotton swabstick in place, an injection of 0.5 mL of 2 percent Lidocaine with 1:200,000 epinephrine was administered into the injection site via a 27-gauge short needle.

Technique of application of topical anesthetic gel: After the oral mucosa was dried with a gauze piece, application of 0.2 mL Benzocaine 20% gel was done with a sterile swab stick on the proposed anesthetic site (palatal mucosa just anterior to the greater palatine foramen) for a period of two minutes as shown in figure. With the cotton swabstick in place an injection of 0.5 mL of 2 percent Lidocaine with 1:200,000 epinephrine was administered into the injection site via a 27-gauge short needle.