Assessing the Efficacy of the Comfort-in Needle-Free Injection System for Managing Pain and Anxiety During Pediatric Dental Injections: A Randomized Split-Mouth Clinical Trial

Local anesthesia administration is one of the major sources of pain, fear, and anxiety in pediatric dental patients. Conventional dental injections may cause discomfort due to needle penetration, tissue pressure, and deposition of anesthetic solution. These experiences may negatively affect child cooperation and future dental attendance. Needle-free injection systems have been developed as an alternative method to deliver local anesthetic solution without needle penetration.

This randomized split-mouth clinical trial compared the Comfort-in needle-free injection system with conventional dental injection in children requiring pulpotomy treatment of bilateral primary first molars. The split-mouth design was used to allow each child to serve as his or her own control, thereby reducing interindividual variability in pain perception and physiological responses.

A total of 60 children aged 5 to 8 years were included. All participants required pulpotomy treatment of bilateral primary first molars located in either the maxilla or mandible. Eligible children had no previous experience with local anesthesia or dental treatment, had no systemic disease or mental disability, had not used medications that could affect pain perception, and demonstrated positive or definitely positive behavior according to the Frankl Behavior Rating Scale during the initial examination.

Each child received both anesthesia techniques in two separate clinical sessions with a minimum interval of one week. In one session, conventional local anesthesia was administered using a dental injector after topical anesthetic application. In the other session, local anesthesia was administered using the Comfort-in needle-free injection system after topical anesthetic application. The sequence of interventions was randomized. Thirty children received conventional injection first and Comfort-in needle-free injection second; the remaining 30 children received Comfort-in needle-free injection first and conventional injection second.

In the conventional injection session, the injection site was dried and topical anesthetic spray was applied for 60 seconds. Local anesthetic solution containing articaine hydrochloride with epinephrine 1:100,000 was then administered using a 27-gauge dental injector. In the Comfort-in session, the injection site was similarly dried and topical anesthetic spray was applied for 60 seconds. Articaine hydrochloride with epinephrine 1:100,000 was administered using the Comfort-in needle-free injection system.