A randomized split-mouth clinical trial comparing 
pain experienced during palatal injections with traditional syringe versus controlled-flow delivery Calaject technique.

OBJECTIVE To compare the pain experienced by patients during injections of local anesthesia in the palate using the traditional syringe and the controlled flow technique with the Calaject system. METHOD AND MATERIALS A single-blind, split-mouth, randomized controlled trial was performed. Twenty-five volunteers were recruited in the Dental Hospital of the University of Barcelona, Spain. Each participant received two injections (0.3 mL of mepivacaine 3%), one with the traditional syringe (control side) and another with the Calaject system (experimental side), both during the same session. Pain intensity was evaluated after each injection with a 100-mm visual analog scale (VAS). A descriptive and bivariate statistical analysis was made. RESULTS The mean pain experienced was 44.8 mm (standard deviation [SD] 19.0, range 8-72) with the traditional injection and 28.8 mm (SD 19.7, range 8-72) with the Calaject system (P < .001). Moderate/severe pain was more frequently referred in the control side (68%) in comparison with the experimental side (28%). CONCLUSION Given the parameters of this study's design, the injection of local anesthetics in the palatal area with the Calaject controlled-flow system seems to reduce pain, in comparison to the use of a traditional syringe.