Effectiveness of Single-use Tips for Dental Air-water Syringes

Objectives: To evaluate the effectiveness of different single-use syringe (SUS) dental tips, firstly by assessing the pressure connection. Secondly, to investigate their drying effectiveness through measuring the peak force at failure during tensile testing of dentine specimens bonded to glass fibre reinforced composite posts.
Methods: The air-water syringe was calibrated to 50 PSI and the air pressure expressed with no tip attached measured. SUS tips were then attached and output air pressure measured. Seven SUS tips were tested. Ethical approval for the use of human teeth was granted. Twenty unrestored, caries free, third molar teeth were sectioned producing 70 specimens, stored in phosphate buffered saline and randomly allocated into groups of ten specimens and an SUS tip. They were mounted in acrylic and polished. Specimens were dried with a tip under standardised conditions, treated using a 3-step etch-prime-bond technique, then had a post bonded perpendicular to the dentine surface. Posts were attached to a microtensile testing machine and the force to detach them measured.
Results: The difference in output pressure between groups proved significant (P < 0.001). The average tensile force at failure was significantly different between groups (P = 0.19) ANOVA analysis.
Conclusions: The pressure output of the syringe is influenced by the SUS tip. The drying effectiveness of the SUS tips was different.