Performance of single-use and multiuse diamond rotary cutting instruments with turbine and electric handpieces Mario Rotella, DDS,a Carlo Ercoli, DDS,b Paul D. Funkenbusch, PhD,c Scott Russell, BS,d and Changyong Feng, PhDe University of Rochester, Rochester, NY Statement of problem. 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. Purpose. 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. Material and 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 (a¼.05). Results. Performance, as measured by the rate of advancement, decreased with the repeated use of rotary cutting instruments (P.05).

Finally, to provide quantitative differences among the 6 groups of rotary cutting instruments that can be more easily understood and used by clinicians, the statistically significant results were also calculated in terms of a percentage (better/worse). To generate these data, the maximum percentage was calculated by which the nominal value of the statistically lower result (such as, rate of advancement) could be increased while retaining the desired level of statistical significance (a¼.05).

RESULTS Load Post hoc analysis revealed that the Two Striper had a statistically significant lower mean load than the other groups (P.05).

Table VII. Rate of advancement/ load for handpiece used

SS White*

Tool

Instrument Type

Mean ±SD

Brasselera

4.50 0.67

SS White

3.45

d

Neo

4.98

d

SSW Piranha

5.97

d

SSW Piranhaa,b

4.76 0.42

Premier Solo

6.07

d

7.06

3.37

Premier Two Striperb

5.28 1.06

Brasseler

Premier Soloa

4.39 0.45

SS Whitea,b

4.92 0.82

Turbine

Neo

Rate of advancement (mm/sec)

Only statistically significant differences are shown and are expressed in percentages. *Group with higher value.

a,b

4.74 0.4

Groups that share same letter are not significantly different (P>.05).

0.30

Rate of advancement/ load for both handpieces

Table VIII. 0.28 0.25

Instrument Type

0.23 0.20

0

2

4

6

8

Cut number Brasseler NEO SSW Piranha

Premier SOLO Premier Two Striper SS White

5 Rate of advancement of 6 different groups for 8 cuts. Rate showed decreasing trend with increase in cut number when averaged over all groups (black dotted line).

Premier Two Striper*

SS White

12.88

Premier Solo

21.27

SS White* d 10.66

SSW Piranha

23.06

d

Neo

23.47

d

Brasseler

27.81

11.36

Only statistically significant differences are shown and are expressed in percentages. *Group with higher value.

Rate of advancement the handpiece systems. For the turbine handpiece, no statistically significant differences were found among groups.

The Two Striper (multiuse) showed a higher rate of advancement compared to the other groups, especially when

The Journal of Prosthetic Dentistry

used with the electric handpiece (Tables III to V). The 4 single-use rotary cutting instruments did not show any statistical difference compared to the SS White (multiuse) with the exception of Brasseler, which exhibited a lower rate (P¼.01). As the number of cuts increased, the rate of advancement decreased (P