Date of Award

Summer 2003

Document Type


Degree Name

Master of Science (MS)


Dental Hygiene


Dental Hygiene

Committee Director

Michele L. Darby

Committee Member

Susan L. Tolle

Committee Member

Deborah Bauman

Call Number for Print

Special Collections LD4331.D46 R93 2003


This study was conducted in order to determine if tactile sensitivity varies in dental hygiene students who use the ultrasonic scaler as compared to those who scale with handactivated instruments. A convenience sample of 40 consenting, first year dental hygiene students were randomly assigned to one of two groups. The 40 students had not yet used the ultrasonic scaler nor had any history of injuries or disabilities to the dominant arm, wrist or hand. After establishing a baseline tactile sensitivity score with the Vibratory Sensory Analyzer (VSA), experimental group subjects used the ultrasonic scaler to remove 4cc's of artificial calculus from a typodont in a controlled, simulated clinical setting for 45-minutes while each control subject manually scaled 4cc's of artificial calculus on a typodont in a controlled, simulated situation for 45-minutes. Tactile sensitivity scores were obtained using the VSA immediately following exposure to either the ultrasonic scaler or hand-activated scaling instruments. Analysis of variance with one repeated measures factor was used to determine between group and within group differences on the pretest and post-test tactile sensitivity scores. Results revealed that following a 45- minute scaling session with the ultrasonic scaler, tactile sensitivity increased. Pre to posttest changes in tactile sensitivity for the ultrasonic scaling group exhibited a much larger threshold as compared to those in the hand-activated scaling group, supporting a gain in students' level of sensitivity with stimulus (vibration). Tactile sensitivity decreased in those who used hand-activated scaling instruments. The thumb, index and middle fingers of students in both groups showed similarities in tactile sensitivity, with the index finger being the most sensitive. Ultrasonic scalers allow the hygienist to exert less pressure and decrease pinching and gripping forces, therefore implying a potential long-term reduction in musculoskeletal disorders. Results also underscore the potential importance of the index finger in detecting calculus and tooth surface irregularities. It was concluded that tactile sensitivity decreases with hand-activated scaling and increases with ultrasonic scaling over a 45-minute period. Short term vibration exposure from the ultrasonic scaler is insufficient to negatively affect tactile sensitivity. The long term effects of scaling with hand-activated and mechanized instruments on tactile sensitivity warrants further testing on clients in a clinical setting.


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