Date of Award

Spring 2004

Document Type


Degree Name

Master of Science (MS)


Dental Hygiene


Dental Hygiene

Committee Director

Susan Lynn Tolle

Committee Member

Michele L. Darby

Committee Member

Martha Walker

Call Number for Print

Special Collections LD4331.D46 H39 2004


The purpose of this study was to determine if differences existed in range of wrist movements and scaling time efficiency in dental hygienists that use a rotating ultrasonic insert as compared to those who use a standard universal insert. A convenience sample of 30 consenting experienced dental hygienists from the Norfolk area who met inclusion criteria was invited to be subjects. Using a crossover research design, each experimental subject used the rotating ultrasonic scaling insert to remove 2 cc artificial calculus from a typodont in a controlled, simulated clinical situation for up to 15 minutes. While scaling, each subject wore the WristSensor™ goniometry gloves (Greenleaf Medical Systems, Palo Alto, California), which determined changes in wrist movements (flexion and extension and ulnar and radial deviations), measured as a deviation from the neutral position. Following a 15-minute rest period, each subject followed the same procedure using the standard universal ultrasonic scaling insert. Scaling time efficiency was determined using a Modified Volpe-Manhold Calculus Index. Data analysis using a paired t-test (p=. 05) revealed no statistically significant differences in wrist movements and scaling time efficiency between subjects using the two different inserts. A multivariate analysis of variance revealed no statistically significant differences in the percentage of time dental hygienists were in high, medium, or low risk posture categories while using the rotating ultrasonic insert compared to the standard universal insert. Based on the results of this laboratory study, dental hygienists using a rotating ultrasonic insert experience no ergonomic advantage in terms of wrist postures or timesavings over a standard insert.


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