Comfort-in Needle-Free Injection System in Pediatric Dental Anesthesia

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.

Pain during anesthesia administration and pulpotomy was assessed using two validated pediatric pain assessment tools: the Face, Legs, Activity, Cry, Consolability scale and the Wong-Baker FACES Pain Rating Scale. Physiological parameters, including systolic blood pressure, diastolic blood pressure, pulse, and oxygen saturation, were recorded before anesthesia, after anesthesia, and after pulpotomy. The total amount of anesthetic solution used, duration of anesthetic effect, postoperative complications, and the child's preference for anesthesia technique were also recorded.

The primary aim of the study was to compare pain perception during local anesthesia administration between the Comfort-in needle-free injection system and conventional dental injection. Secondary aims included comparing anesthetic efficacy during pulpotomy, physiological responses, amount of anesthetic solution required, duration of anesthetic effect, postoperative complications, and patient preference between the two anesthesia techniques.