Comparative evaluation of injection pain during administration of local anaesthesia after topical anaesthetic gel versus cryotherapy application: A randomised controlled trial

Introduction: Pain management is a critical component of successful endodontic treatment, particularly during intraoperative and postoperative stages. Adequate control of pain not only enhances patient comfort but also contributes to overall treatment efficacy and patient compliance. Local anesthetics (LAs) are indispensable in minimizing discomfort associated with a variety of dental, endodontic, and minor surgical procedures.

To minimize injection-related discomfort, a range of strategies has been investigated. These include the use of topical anesthetic gels, precooling techniques (such as ice or refrigerant spray), buffering of anesthetic solutions to reduce acidity and injection pain, and advanced delivery systems like computer-controlled local anesthetic delivery (CCLAD) devices.

Given this gap in evidence, the present clinical trial aims to evaluate and compare the effectiveness of a topical anesthetic gel and cryotherapy in reducing pain perception during the administration of local anesthesia in dental patients.

Aim:  The aim of this study is to compare and evaluate of injection pain during administration of local anesthesia after topical anesthetic gel versus cryotherapy application.

Objectives:

1. To evaluate the injection pain during administration of local anesthesia after topical anesthetic gel versus cryotherapy application.
2. To compare the injection pain during administration of local anesthesia after topical anesthetic gel versus cryotherapy application.

Primary Hypothesis: There is a significant difference between the injection pain during administration of local anesthesia after topical anesthetic gel versus cryotherapy application.

Null Hpothesis: There is no significant difference between the injection pain during administration of local anesthesia after topical anesthetic gel versus cryotherapy application.

Study design: Two arm, crossover controlled trial.

Study Population: Patients visiting the Department of Conservative Dentistry and Endodontics for endodntic treatment.

Sample Size: the total sample size estimated was 17 per group.

Group allocation: For patients requiring endodontic or restorative treatment involving two or more teeth, two separate pre-treatment protocols corresponding to their assigned group will be applied—one before anesthesia for each tooth. This approach will be adopted to optimize local anesthesia efficacy across multiple sites, ensuring adequate pain control during treatment of each tooth. The timing of each pre-treatment and injection will be standardized to maintain consistency and reduce variability in anesthetic effectiveness. Group A- Topical Anaesthetic gel. Group B- Cryotherapy.

Pain assessment: Pain perception during the administration of local anesthesia will be assessed using a VAS scale. The VAS will consist of a 10 cm horizontal line, where 0 represents "no pain" and 10 represents the "worst imaginable pain." Each patient will be informed about the purpose and use of the scale prior to the procedure.