Comparison of Pain and Stress Due to Buccal Infiltration Anesthesia Using “Two-Stage Injection” and “Computer-Controlled Injection” Techniques in Pediatric Patients: A Clinical Trial

Background: Considering the importance of painless injection is dentistry, the aim of the present study was to compare the level of experienced pain and stress associated with two different injection methods used for buccal infiltration, namely: the two-stage injection and the computer-controlled injection techniques.Methods and Materials: This cross-over clinical trial study was conducted in a split-mouth design and included a total of 28 healthy children with 5-7 years of age who required pulpotomy treatment on the both primary maxillary first molars. Two-stage and computer-controlled injection anaesthesia were used to perform local buccal infiltration and anesthetize the pulp of the teeth. The level of stress was assessed through pulse rate. Pain was measured using the objective Sound Eye Motor (SEM) Pain scale and also subjectively using Faces criterion. Pulse rate and Faces criterion were measured at three different time points: one minute before injection (T1), during injection (T2) and at the time of pulp exposure (T3). SEM was only measured at T2.Results: The average pulse rate during injection (T2), in the computer-controlled injection technique (113.5 ± 1.88 bpm) was significantly greater than that of the two-stage injection technique (111.5 ± 1.77 bpm) (P=0.030). Pulse rate was also significantly less at T3 when the two-stage injection technique was used (P=0.003). There was a statistically significant difference between mean pulse rate values measured at T1 and T2 (P=0.007) as well as T1 and T3 (P=0.009). There was a statistically significant difference between the frequency of Faces criterion of the two techniques when during injection (T2) (P=0.004). Regarding SEM Pain Sclae, a significant difference was not found between the two techniques (P=0.529).Conclusion: The two-stage injection technique demonstrated superior results in terms of pain and stress control compared to the computer-controlled injection technique. This technique seems to be a favourable method for achieving local anaesthesia with minimal pain and stress in is children.