In vitro comparison of the cutting efficiency and temperature production of ten different rotary cutting instruments. Part II: electric handpiece and comparison with turbine.

STATEMENT OF PROBLEM The cutting behavior of dental rotary cutting instruments is influenced by the handpiece used. While the turbine handpiece has been extensively tested in previous studies, limited published information exists on the use of rotary cutting instruments with the electric handpiece system and on possible interactions between rotary cutting instruments and handpiece type. PURPOSE The purpose of this study was to examine the cutting performance of a wide selection of rotary cutting instruments tested with the electric handpiece and compare the results with those of the air-turbine handpiece (Part I), identifying possible interactions between handpiece type and rotary cutting instruments. MATERIAL AND METHODS Ten groups of rotary cutting instruments (n=30) designed for tooth preparation were selected: 9 diamond (7 multi-use, 2 disposable) and 1 carbide. Macor blocks (n=75) were used as a substrate, and 4 cuts were made on each specimen, using a new rotary cutting instrument each time, for a total of 300 cuts. The cuts were performed with an electric handpiece (Intramatic Lux K200), with the same methods used in the Part I study. To qualitatively evaluate the rotary cutting instrument surface characteristics, 1 specimen from each group was examined 3 times with a scanning electron microscope (SEM): before use, then after use, but before being cleaned and sterilized, and finally, after ultrasonic cleaning. To compare rotary cutting instrument performance between the turbine and electric handpieces, the data were analyzed using 2-way ANOVA to study the main effects of the group of rotary cutting instruments, handpieces, and their interaction. For analysis of the significant main effect, 1-way ANOVA and Tukey's Studentized Range test were used (alpha=.05). RESULTS Compared to the baseline temperature, all rotary cutting instruments showed a reduction of the temperature in the simulated pulp chamber when tested with the electric handpiece. The Great White Ultra (carbide bur) showed the highest rate of advancement (0.17 mm/s) and lowest applied load (108.35 g). Considering all rotary cutting instruments as a single group, the electric handpiece showed mean lower temperature (26.68 degrees C), higher rate of advancement (0.12 mm/s), and higher load (124.53 g) than the air-turbine handpiece (28.37 degrees C, 0.11 mm/s, and 121.7 g, respectively). Considering each single group of rotary cutting instruments, significant differences were found for the electric or air-turbine handpiece. CONCLUSIONS The tested carbide bur showed greater cutting efficiency than the tested diamond rotary cutting instruments when used with the electric handpiece. The electric handpiece showed a higher cutting efficiency than the turbine, especially when used with the carbide bur, probably due to its greater torque.

[1]  H Miyawaki,et al.  Dental high-speed cutting of four cast alloys. , 1993, Journal of oral rehabilitation.

[2]  Douglas H Kazen.  Modern electric handpieces feature improved benefits for today's dental surgeon. , 2005, Dental assistant.

[3]  Eikenberg Sl,et al.  Comparison of the cutting efficiencies of electric motor and air turbine dental handpieces. , 2001 .

[4]  Sharon C Siegel,et al.  The effect of handpiece spray patterns on cutting efficiency. , 2002, Journal of the American Dental Association.

[5]  Eames Wb,et al.  Ten high-speed handpieces: evaluation of performance. , 1979 .

[6]  A Schuchard,et al.  Comparative efficiency of rotary cutting instruments. , 1965, The Journal of prosthetic dentistry.

[7]  E S Pilcher,et al.  Comparison of cutting rates among single-patient-use and multiple-patient-use diamond burs. , 2000, Journal of prosthodontics : official journal of the American College of Prosthodontists.

[8]  S C Siegel,et al.  Cutting efficiency of three diamond bur grit sizes. , 2000, Journal of the American Dental Association.

[9]  D G Stone,et al.  Restorative dentistry: High and low torque handpieces: cutting dynamics, enamel cracking and tooth temperature , 2000, British Dental Journal.

[10]  J. Kumpula,et al.  Characteristics of some air-turbine handpieces. , 1962, Journal of the American Dental Association.

[11]  Kenneth R. Cantwell,et al.  Thermogenics in cavity preparation using air turbine handpieces: The relationship of heat transferred to rate of tooth structure removal , 1964 .

[12]  W B Eames,et al.  Ten high-speed handpieces: evaluation of performance. , 1979, Operative dentistry.

[13]  David L Hall,et al.  Methicillin-resistant Staphylococcus aureus and infection control for restorative dental treatment in nursing homes. , 2003, Special care in dentistry : official publication of the American Association of Hospital Dentists, the Academy of Dentistry for the Handicapped, and the American Society for Geriatric Dentistry.

[14]  J E Dyson,et al.  Dental air turbine handpiece performance testing. , 1995, Australian dental journal.

[15]  Brian J Kenyon,et al.  Comparison of cavity preparation quality using an electric motor handpiece and an air turbine dental handpiece. , 2005, Journal of the American Dental Association.

[16]  Gordon J Christensen,et al.  Are electric handpieces an improvement? , 2002, Journal of the American Dental Association.

[17]  S L Eikenberg.  Comparison of the cutting efficiencies of electric motor and air turbine dental handpieces. , 2001, General dentistry.

[18]  S C Siegel,et al.  Handpiece coolant flow rates and dental cutting. , 2000, Operative dentistry.

[19]  H Shintani,et al.  Cutting effectiveness and wear of carbide burs on eight machinable ceramics and bovine dentin. , 1991, Dental materials : official publication of the Academy of Dental Materials.

[20]  S C Siegel,et al.  Irrigation rates and handpieces used in prosthodontic and operative dentistry: results of a survey of North American dental school teaching. , 2000, Journal of prosthodontics : official journal of the American College of Prosthodontists.

[21]  Uri Ben-Hanan,et al.  Tooth preparation: a study on the effect of different variables and a comparison between conventional and channeled diamond burs. , 2004, Journal of prosthodontics : official journal of the American College of Prosthodontists.

[22]  H Shintani,et al.  Studies on dental high-speed cutting with carbide burs used on bovine dentin. , 1994, The Journal of prosthetic dentistry.

[23]  P J Brockhurst,et al.  Dynamic measurement of the torque-speed characteristics of dental high speed air turbine handpieces. , 1994, Australian dental journal.

[24]  S C Siegel,et al.  Assessing the cutting efficiency of dental diamond burs. , 1996, Journal of the American Dental Association.

[25]  A. Amis,et al.  The magnitude of cutting forces at high speed. , 2003, The Journal of prosthetic dentistry.

[26]  S C Siegel,et al.  Dental cutting with diamond burs: heavy-handed or light-touch? , 1999, Journal of prosthodontics : official journal of the American College of Prosthodontists.

[27]  H Shintani,et al.  Studies on dental high-speed cutting. , 1995, Journal of oral rehabilitation.

[28]  W. S. Brown,et al.  Effect of Cooling Techniques on Temperature Control and Cutting Rate for High-Speed Dental Drills , 1978, Journal of dental research.

[29]  I A Westland.  The energy requirement of the dental cutting process. , 1980, Journal of oral rehabilitation.

[30]  F. Ozer,et al.  In vitro assessment of temperature change in the pulp chamber during cavity preparation. , 2004, The Journal of prosthetic dentistry.

[31]  A Matsui,et al.  Dental cutting behaviour of mica-based and apatite-based machinable glass-ceramics. , 1990, Journal of oral rehabilitation.

[32]  Paul D. Funkenbusch,et al.  In vitro comparison of the cutting efficiency and temperature production of 10 different rotary cutting instruments. Part I: Turbine. , 2009, The Journal of prosthetic dentistry.