The effectiveness of a needle-free system in reducing injection pain during palatal infiltrative anesthesia in children: a randomized clinical study

Background: Dental palatal infiltrative injection challenges tolerance in pediatric patients. The study aimed to evaluate the pain and effectiveness of the Comfort-In™ injection compared to dental needle injection using palatal infiltrative anesthesia to extract upper permanent first molars in children. Methods: This randomized, parallel-arm, prospective clinical trial was conducted in children aged 7 to 14 years who required the extraction of upper permanent first molars. Fifty participants were randomized into two groups: the Comfort-In™ and the dental needle injection group. Pain acceptance was evaluated during the palatal infiltrative anesthesia using the Wong-Baker FACES Pain Rating Scale (WBFPRS) and the Face, Leg, Activity, Cry, Consolability (FLACC) Scale. Extra-dose requirements were assessed in both groups. Data were analyzed using version 4.4.1 of the R programming language, and the significance level was set at p < 0.05. Results: The WBFPRS was evaluated for pain acceptance, and a statistically significant difference was found, with the Comfort-In™ injection group demonstrating better pain acceptance compared to the dental needle injection group (p = 0.003). There was no statistical difference between the Comfort-In™ injection system and the dental needle injection in FLACC scores (p = 0.05) and the extra-dose requirements (p = 0.05). In the multiple regression for FLACC, the dental needle method increased scores (β ± SE (Standard Error) = 0.53 ± 0.20; p = 0.012). In the ordinal logistic regression for WBFPRS, it also yielded higher scores (β ± SE = 3.27 ± 0.73; p < 0.001). Conclusions: Dental needle injection anesthesia was associated with more pain during palatal anesthesia than Comfort-In™ injection method. Although Comfort-In™ injection system generally provided adequate anesthesia, it required an extra dose in some cases. Nevertheless, due to its lower pain perception and needle-free application, the Comfort-In™ injection system is recommended as a suitable alternative for palatal anesthesia in pediatric patients. Clinical Trial Registration: ClinicalTrials.gov: NCT06606587.