Effect of Different Types of Dental Stools on Muscle Activity During Execution of Preclinical Procedures

This study investigated the effect of different dental stools on muscular activity in the upper and abdominal regions, and the angular deviation of the neck and trunk during preclinical procedures.

An experimental laboratory study was conducted with the response variables including (1) muscular activity of the trapezius, rectus abdominis, and paravertebral muscles, measured by surface electromyography and (2) angular deviation from the neutral position of the neck and trunk. The independent variable was the type of dental stool (conventional stool, saddle seat, or seatball). Class I preparations were performed (N = 120) on artificial first molars. Working postures were recorded and angular deviations were measured using the "Postural Assessment Software-SAPO." A one-way analysis of variance, Tukey and Games-Howell post hoc tests were performed.

Stool type did not affect the activity of the paravertebral and rectus abdominis muscles (p > 0.05). Less activity was observed in the right trapezius muscle during cavity preparations of teeth 26 (p = 0.006) and 36 (p = 0.046) with conventional stool. The saddle seat led to less activity in the left trapezius during work on tooth 26 (p = 0.040). For the neck, a greater angular deviation was observed with the saddle seat on the upper left hemiarch (p = 0.020), and with the saddle seat and seatball on the lower left hemiarch (p = 0.019). The trunk showed greater angular deviation during work with the saddle seat and seatball for all hemiarches (p < 0.001-0.003).

Stool type did not influence muscle activity, but the unconventional stools led to greater angular deviations in the neck and trunk.