Prolonged use of manual dental instruments often contributes to operator discomfort, muscle fatigue, and work-related musculoskeletal disorders (MSDs). This pilot in vivo investigation explored how an innovative ergonomic handle sheath affects muscle activity, perceived comfort, and fatigue during two common dental procedures: (a) ultrasonic scaling performed by hygienists with and without MSDs, and (b) tooth cavity preparation performed by dentists using a micromotor handpiece. Twenty dental hygienists were divided equally into two groups—those without MSDs and those previously diagnosed with such conditions. Each group carried out scaling using a piezoelectric device, both with and without the ergonomic sheath. In addition, ten healthy dentists prepared four standardized cavities using a dental micromotor under the same conditions. Electromyographic data from four target muscles, along with self-reported comfort and fatigue ratings, were collected. The dataset was analyzed using a repeated-measures ANOVA followed by Tukey’s post-hoc comparisons.
Use of the ergonomic sheath led to statistically significant improvements in comfort and reductions in fatigue and muscular workload for both dental tools. Although hygienists with MSDs exhibited higher muscle activity overall and appeared to benefit slightly more from the sheath, these group differences did not reach statistical significance. The findings indicate that an ergonomic handle sheath can enhance the usability and ergonomic efficiency of both ultrasonic scalers and micromotors, suggesting its potential value in minimizing muscle strain and improving practitioner comfort during clinical practice.
