Efficacy versus health risks: An in vitro evaluation of power-driven scalers

Abstract

Background: Power-driven instrumentation of root surfaces during supportive periodontal therapy is an alternative to hand instrumentation. The purpose of this pilot in vitro study was to investigate the efficacy of sub- and supragingival plaque removal with a sonic (AIR: Synea, W and H, Bürmoos, Austria) and two ultrasonic devices (TIG: Tigon+, W and H, Bürmoos, Austria; VEC: Vector, Dürr, Bietigheim-Bissingen, Germany) as well as the health-risk for dental professionals during treatment.

Materials and methods: The power-driven devices were utilized to remove plaque from model teeth in dummy heads. The percentage of residual artificial plaque after 2 min of supra- or subgingival instrumentation was calculated by means of image-processing techniques at four sites (n = 576) of each tooth. The Health-Risk-Index (HRI: spatter/residual plaque quotient) with the different power-driven devices was assessed during treatment.

Results: The smallest amounts of residual plaque were found for the sonic device AIR (8.89% ± 10.92%) and the ultrasonic scaler TIG (8.72% ± 12.02%) (P = 0.707). Significantly more plaque was remained after the use of the ultrasonic scaler VEC (18.76% ± 18.07%) (P < 0.001). Irrespectively of the scaler, efficacy was similar sub- (10.7% ± 11.6%) and supragingivally (13.5% ± 17.2%) (P = 0.901). AIR/TIG demonstrated equal residual amounts of plaque sub- (P = 0.831) as well as supragingivally (P = 0.510). However, AIR/VEC and TIG/VEC were significantly in favor of AIR and TIG (P < 0.001). In contrast, the lowest HRI was found after using VEC (0.0043) and differed considerably for AIR (0.2812) and TIG (0.0287).

Conclusion: Sonic devices are as effective as ultrasonic devices in the removal of biofilm but bear a higher risk to the dental professional's health concerning the formation of spatter.

Keywords: Aerosol; dental prophylaxis; plaque; scaling.

Figure 1

The darkened treatment room with the dummy head under normal light conditions and black lacquer coverage of all surfaces

Figure 2

The modified periodontitis models for maxilla and mandible with horizontal bone loss and gingival masks of persistently pliable silicone (Frasaco, Tettnang, Germany); (a1) upper right and (b1) lower right side as well as (a2) upper left and (b2) lower left side. The transparent blue hatching in the right and left picture illustrate the coated tooth surface

Figure 3

(a) Illustration of the measurement of subgingival residual plaque of tooth 31 after working with a sonic scaler (AIR) for 120 s. The enlargements show the measurement with the standardized data masks with quadrangle arrays. (b) For demonstration purposes; the experimental setup in the darkened treatment room under inverse light conditions with the operator in 12 o’clock treatment position. The enlargement shows part of a photo taken under experimental conditions to measure the spatter distribution

Figure 4

The three tested powered devices with the appending slimline tips. From left to right: Sonic hand-piece (AIR), ultrasonic hand-piece (TIG) and ultrasonic hand-piece (VEC)

Figure 5

Residual plaque (right side of the graph) and Health-Risk-Index (left side of the graph) divided by the different powered devices: Sonic scaler (AIR) and two ultrasonic scalers (TIG and VEC) as well as the location (supra-, subgingival and in total)

Figure 6

Illustration of residual plaque of tooth 41. Reason for ineffectivity could be: (a) Forgetting to treat a site/area, (b) Too fast and too hectical working strokes, (c) No systematical work, (d) Operator didn’t reach the plaque at the pocket bottom