Comparison of cutting efficiencies between electric and air-turbine dental handpieces.
BACKGROUND
Dentistry is gravitating toward the increased use of electric handpieces. The dental professional should have sufficient evidence to validate the switch from an air-turbine handpiece to an electric handpiece. However, there is little research quantifying the cutting efficiency of electric and air-turbine handpieces. Studies that do quantify cutting efficiency typically do so with only a single material.


OBJECTIVE
The purpose of this study was to compare the cutting efficiency of an electric handpiece and an air-turbine handpiece, using various materials commonly used in dentistry.


METHODS
Seven materials: Macor (machinable glass ceramic), silver amalgam, aluminum oxide, zirconium oxide, high noble metal alloy, noble metal alloy, and base metal alloy, were each cut with a bur 220 times; 110 times with an electric handpiece, and 110 times with an air-turbine handpiece. The weight difference of the material was calculated by subtracting the weight of the material after a cut from the weight of the material before the cut. The cutting efficiency was calculated by dividing the weight difference by the duration of the cut (g/s). Data were analyzed by a 2-way analysis of variance followed by Tukey's Honestly Significant Difference (HSD) test (alpha=.05).


RESULTS
The electric handpiece cut more efficiently than the air-turbine handpiece (F=3098.9, P<.001). In particular, the high noble metal alloy, silver amalgam, and Macor were cut more efficiently with the electric handpiece (0.0383 +/-0.0002 g/s, 0.0260 +/-0.0002 g/s, and 0.0122 +/-0.0002 g/s, respectively) than with the air-turbine handpiece (0.0125 +/-0.0002 g/s, 0.0142 +/-0.0002 g/s, and 0.008 +/-0.0002 g/s, respectively).


CONCLUSIONS
The electric handpiece is more efficient at cutting various materials used in dentistry, especially machinable glass ceramic, silver amalgam, and high noble alloy, than the air-turbine handpiece.
Postdoctoral Program in Prosthodontics, Department of Endodontics, Prosthodontics, and Operative Dentistry, Baltimore College of Dental Surgery, University of Maryland, Baltimore, MD, USA.
Charlson
C
Choi
Carl F
CF
Driscoll
Elaine
E
Romberg
D000388:Air; D000537:Aluminum Oxide / Q000737:chemistry; D002244:Carbon / Q000737:chemistry; D002516:Ceramics / Q000737:chemistry; D003722:Dental Alloys / Q000737:chemistry; D003723:Dental Amalgam / Q000737:chemistry; D003754:Dental High-Speed Equipment / Q000592:standards*; D003764:Dental Materials / Q000737:chemistry; D003776:Dental Porcelain / Q000737:chemistry; D018130:Diamond / Q000737:chemistry; D004526:Efficiency; D011211:Electric Power Supplies; D004867:Equipment Design; D006047:Gold Alloys / Q000737:chemistry; D006801:Humans; D008422:Materials Testing; D012834:Silver / Q000737:chemistry; D013499:Surface Properties; D015040:Zirconium / Q000737:chemistry
D003722:Dental Alloys; D003764:Dental Materials; D006047:Gold Alloys; D003776:Dental Porcelain; D012834:Silver; D002244:Carbon; D018130:Diamond; D003723:Dental Amalgam; C023506:Glass ceramics; D015040:Zirconium; D000537:Aluminum Oxide; C028541:zirconium oxide