Movement control during aspiration with different injection systems via video monitoring-an in vitro model

The aim of the present study was an evaluation of movement during double aspiration by different manual syringes and one computer-controlled local anesthesia delivery system (C-CLAD).

With five different devices (two disposable syringes (2, 5 ml), two aspirating syringes (active, passive), one C-CLAD), simulation of double aspiration in a phantom model was conducted. Two experienced and two inexperienced test persons carried out double aspiration with the injection systems at the right and left phantom mandibles in three different inclination angles (n = 24 × 5 × 2 for each system). 3D divergences of the needle between aspiration procedures (mm) were measured with two video cameras.

An average movement for the 2-ml disposal syringe of 2.85 mm (SD 1.63), for the 5 ml syringe of 2.36 mm (SD 0.86), for the active-aspirating syringe of 2.45 mm (SD 0.9), for the passive-aspirating syringe of 2.01 mm (SD 0.7), and for the C-CLAD, an average movement of 0.91 mm (SD 0.63) was seen. The movement was significantly less for the C-CLAD compared to the other systems (p < 0.001). The movement of the needle in the soft tissue was significantly less for the C-CLAD compared to the other systems (p < 0.001).

A difference in involuntary movement of the syringe could be seen in comparison between manual and C-CLAD systems. Launching the aspiration by a foot pedal in computer-assisted anesthesia leads to a minor movement.

To solve the problem of movement during aspiration with possibly increased false-negative results, a C-CLAD seems to be favorable.