Pinch forces and instrument tip forces during periodontal scaling.

BACKGROUND The prevalence of upper-extremity musculoskeletal disorders, such as tendinitis, is elevated among dental practitioners. An important risk factor for these disorders is forceful pinching; however, the pinch forces and instrument forces during scaling are unknown. METHODS Six dentists and six senior-year dental students were recruited to use an instrumented periodontal scaler to perform their usual dental scaling work on patients. Thumb pinch force was measured by a pressure sensor, whereas the forces developed at the instrument tip were measured by a six-axis load cell. RESULTS Dental students applied greater mean peak pinch force (35.7 +/- 3.8 N) compared to dentists (24.5 +/- 4.1 N) (P = 0.001). On the other hand, the peak forces generated at the instrument tip, which were directly related to the productivity of the dental scaling task, were higher among the dentists. The application of pinch force by dentists was related to the required scaling forces, whereas students applied excessive pinch force to the tools. CONCLUSIONS Increased experience in periodontal scaling leads to the application of less pinch force to accomplish scaling. Nonetheless, the applied peak pinch forces in both groups are high and may pose a risk for the development of musculoskeletal disorders of the distal upper extremity.