An evaluation of rotational stability in endodontic electronic motors

Article information

Restor Dent Endod. 2010;35(4):246-256

Publication date (electronic) : 2010 July 31

doi : https://doi.org/10.5395/JKACD.2010.35.4.246

Se-Hee Park ¹, Hyun-Woo Seo ², Chan-Ui Hong ³

¹Department of Conservative Dentistry, College of Dentistry, Gangneung-Wonju National University, Wonju, Korea.

²Department of Pediatric Dentistry, College of Dentistry, Gangneung-Wonju National University, Wonju, Korea.

³Department of Conservative Dentistry, Plant Dental Hospital, Daejeon, Korea.

Corresponding Author: Se-Hee Park. Department of Conservative Dentistry College of Dentistry, Gangneung-Wonju National University, 123 Chibyon-dong Gangwon-do, Korea. Tel: +82-33-640-2760 Fax: +82-33-640-3103, drendo@gwnu.ac.kr

Received 2010 April 28; Revised 2010 May 12; Accepted 2010 June 11.

Abstract

The purpose of this study was to evaluate a rotational stability of endodontic electronic motors by comparing the changes of rotational speed, depending on the number of usages and with/without static load. Twelve new endodontic electronic motors were used in this study. Non contact type digital tachometer was used for measuring the rotational speed of handpiece. True RMS Multimeter was used for measuring the voltages and the electric currents. All measurements were recorded every 10 seconds during 10 minutes and repeated 9 times. Five repetition was done per each electronic motor. To statistical analysis, student t-test, repeated measures and Scheffe's post-hoc tests were performed. In the same motor group, there was no significant difference in all measurements. In all groups, there was no significant difference in the amount of rotational speed changes depending on the number of usages and with/without static load. In the limitation of this study, the results showed that all kinds of endodontic electronic motors in this study had an established rotational stability. Therefore they could be safely used in root canal treatment with a reliable maintenance of rotational speed, regardless of the number of usages and with/without load.

Keywords: Rotational stability; Electronic motor; Rotational speed; RPM; Endomate TC; X-Smart

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Article information Continued

Figure 1

Diagram of measuring method.

a: Measurement of TECNIKA and AEU-25, under the unloading condition.

b: Measurement of TECNIKA and AEU-25, under the loading condition.

c: Measurement of X-Smart and Endomate TC, under the unloading condition.

d: Measurement of X-Smart and Endomate TC, under the loading condition.

Figure 2

Actual rotational speed (rpm) of each electronic motors.

horizontal axis: The number of measuring times (× 10 seconds), vertical axis: Rotational speed (RPM).

a: Actual rotational speed of TECNIKA, under the unloading condition.

b: Actual rotational speed of TECNIKA, under the loading condition.

c: Actual rotational speed of AEU-25, under the unloading condition.

d: Actual rotational speed of AEU-25, under the loading condition.

e: Actual rotational speed of X-Smart (AC adapter), under the unloading condition.

f: Actual rotational speed of X-Smart (AC adapter), under the loading condition.

g: Actual rotational speed of X-Smart (Battery), under the unloading condition.

h: Actual rotational speed of X-Smart (Battery), under the loading condition.

i: Actual rotational speed of Endomate TC, under the unloading condition.

j: Actual rotational speed of Endomate TC, under the loading condition.

Figure 3

Actual DC voltage (V) depending on repeated using.

a: X-Smart (AC adapter) under the unloading condition.

b: X-Smart (AC adapter) under the loading condition.

c: X-Smart (Battery) under the unloading condition.

d: X-Smart (Battery) under the loading condition.

e: Endomate TC under the unloading condition.

f: Endomate TC under the loading condition.

Figure 4

Actual DC current (mA) depending on repeated using.

a: X-Smart (AC adapter) under the unloading condition.

b: X-Smart (AC adapter) under the loading condition.

c: X-Smart (Battery) under the unloading condition.

d: X-Smart (Battery) under the loading condition.

e: Endomate TC under the unloading condition.

f: Endomate TC under the loading condition.

Table 1

Motor preset values and measured item

^†P: Power supplied from AC adapter

^††B: Power supplied from rechargeable battery

Table 2

Mean values (± standard deviation) of actual rotational speed

^†P: Power supplied from AC adapter

^††B: Power supplied from Rechargeable battery

Student t-test analysis, significantly different at p < 0.05.

The different letter means significant difference between groups.

Table 3

P-values in changes of rotational speed in same kind of motors

^†P: Power supplied from AC adapter

^††B: Power supplied from Rechargeable battery

Repeated measure analysis, significantly different at p < 0.05.

Table 4

Comparison of voltages and currents depending on repeated using and with/without loading

^†P: Power supplied from AC adapter

^††B: Power supplied from Rechargeable battery

Repeated measure analysis, significantly different at p < 0.05.

The different letter means significant difference between groups (p < 0.05).