Performance of single-use and multiuse diamond rotary cutting instruments with turbine and electric handpieces.
BACKGROUND
As single-use rotary cutting instruments and electric handpieces become more available, the performance of these instruments with electric as compared to turbine handpieces requires evaluation. In addition, if rotary cutting instruments marketed as single-use instruments are used for multiple patients, the effects on their performance of cleaning, sterilization, and repeated use are of interest to the clinician.


OBJECTIVE
The purpose of the study was to evaluate how the cleaning, autoclaving, and repeated use of single-use and multiuse rotary cutting instruments, with either a turbine or electric handpiece, affected their performance.


METHODS
The effects on cutting performance of 2 handpieces (turbine and electric), 2 cleaning and sterilization conditions (cleaned and autoclaved versus noncleaned and nonautoclaved), and 6 different diamond rotary cutting instruments (4 single-use and 2 multiuse) during simulated tooth preparations were evaluated by using a 24-treatment condition full-factorial experimental design. A computer-controlled dedicated testing apparatus was used to simulate the cutting procedures, and machinable glass ceramic blocks were used as the cutting substrate for tangential cuts. In addition, for each treatment condition, 8 consecutive cuts, for a total of 192 cuts, were measured to assess the durability of the rotary cutting instruments. A linear mixed model was used to study the effect of instrument type, handpiece, cleaning, and sterilization, as well as the status and number of cuts on the outcome variables. The Tukey honestly significant difference test was used for the post hoc pairwise comparisons (α=.05).


RESULTS
Performance, as measured by the rate of advancement, decreased with the repeated use of rotary cutting instruments (P<.001), while cleaning and sterilization procedures improved the average performance of the 8 cuts (P=.002). The electric handpiece showed a greater load than the turbine (P<.001) and a lower rate/load metric, but no differences in the rate of advancement. Significant differences were also detected among the different rotary cutting instruments tested with the Two Striper, which showed the highest cumulative performance of all groups.


CONCLUSIONS
The repeated use of both single-use and multiuse rotary cutting instruments decreased cutting performance. The use of a cleaning and sterilization procedure between cuts improved the average cutting performance. During a tangential cutting process, although the ease of advancement (rate/load) was greater for the turbine, the electric handpiece did not produce a statistically different cutting rate.
Former Resident, Division of Prosthodontics, Eastman Institute for Oral Health, University of Rochester, Rochester, NY; and Private practice (currently), Toronto, Canada. Electronic address: drmariorotella@gmail.com.
Mario
M
Rotella
Associate Professor, Chair, and Program Director, Division of Prosthodontics, Eastman Institute for Oral Health, University of Rochester, Rochester, NY.
Carlo
C
Ercoli
Professor, Department of Mechanical Engineering, Hajim School of Engineering and Applied Sciences, University of Rochester, Rochester, NY.
Paul D
PD
Funkenbusch
Technical Associate, Department of Mechanical Engineering, Hajim School of Engineering and Applied Sciences, University of Rochester, Rochester, NY.
Scott
S
Russell
Associate Professor, Department of Biostatistics and Computational Biology, University of Rochester, Rochester, NY.
Changyong
C
Feng
D002516:Ceramics / Q000737:chemistry; D003754:Dental High-Speed Equipment / Q000592:standards*; D003764:Dental Materials / Q000737:chemistry; D003902:Detergents / Q000737:chemistry; D018130:Diamond / Q000737:chemistry*; D055615:Electrical Equipment and Supplies / Q000592:standards*; D017743:Equipment Reuse; D006801:Humans; D008422:Materials Testing; D013242:Sterilization / Q000379:methods; D013314:Stress, Mechanical; D019246:Tooth Preparation / Q000295:instrumentation* / Q000592:standards
D003764:Dental Materials; D003902:Detergents; D018130:Diamond; C023506:Glass ceramics