Effect of Different Types of Stools on Working Posture, Discomfort and Productivity in Dentistry

Objective: This study evaluated different stools on working posture, discomfort and productivity during cavity preparations. Methods: An experimental laboratory-based simulated study was performed. The response variables were the variation in bilateral muscle contraction of the abdominal, lumbar, and posterior thigh regions using surface thermography as proxy measure; the risk of developing musculoskeletal disorders in the upper limbs using the Rapid Upper Limb Assessment; adherence to ergonomic posture requirements through the modified Compliance Assessment Dental Ergonomic Posture; angular deviation from the neutral position of the neck and trunk; perception of discomfort in the abdominal, lower back, and thighs using the visual analogue scale; and productivity. Independent variables were the type of stool (conventional, saddle, or Seatball) and arch (upper or lower). A single operator performed class I tooth preparations on arch simulator plates during 90-minutes per period. For each experimental condition, 10 postural assessment periods were used (N=60 postures). Descriptive statistics were analyzed, and the assumptions of normality and homoscedasticity were verified. Two-way parametric and non-parametric ANOVA with Tukey’s post-hoc test were performed (α=0.05). Results: There was no significant interaction between stool and arch for any evaluated variable (p=0.449–0.915). There was higher muscle contraction during work with conventional stool for the lumbar region (p