An evidence-based review of ergonomic features of dental hygiene instruments

The purpose of this paper is to describe the research identifying dental hygiene risk factors, outline the structural characteristics of the various tools that dental hygienists use and discuss the evidence to support ergonomic tool re-designs.

Two databases, Medline and Cinahl, were used to identify epidemiological research studies from 1998--2008 that describe the prevalence of musculoskeletal disorders in dental hygienists. The length, diameter, mass and padding of twenty-one (n=21) dental instruments and instrument grip combinations and twenty-two (n=22) mirrors and mirror grip combinations are described.

The length, mass and diameter of dental instruments and dental mirrors ranged from 16.3 cm to 17.5 cm and 15.9 cm to 18.5 cm, from 10.0 g to 25.0 g and 5.0 g to 30.0 g, and from 6.5 mm to 11 mm and 6 mm to 14 mm, respectively. Padding instruments and mirrors increased the mass by approximately 5.0 g. The literature does not suggest an optimal length for dental instruments or dental mirrors. The literature suggests that the optimal diameter for dental instruments and mirrors is at least 10 mm, the optimal weight is 15.0 g or less, and padding decreases muscle activity.

Dental hygienists should be educated to select a variety of instrument handles based upon the parameters described above.