A Novel Methodology to Evaluate the Use of an Ultrasonic Tip

Evaluation of the breakage of orthograde endodontic ultrasonic tips

INTRODUCTION

The objective of this study was to compare the breakage of 3 endodontic ultrasonic tips when removing dentin from extracted molars.

METHODS

Three tips were tested (n = 10): BUC 1A (Obtura Spartan, Fenton, MO), CPR 5D (Obtura Spartan), and EDS 5E (Essential Dental Systems, South Hackensack, NJ). Extracted molars were prepared and mounted to a slow-speed alternating-current motor of a custom testing apparatus, which provided a 5-mm linear movement at an approximate rate of 4 mm/s. A 20-g axial force was applied to the tooth specimens. The MiniEndo II Ultrasonic Unit (SybronEndo, Orange, CA) was used to operate the ultrasonic tips in 20-second cycles with 10 seconds of rest between each cycle. The process was repeated until breakage was observed or 10 minutes had elapsed. The time to breakage was recorded for each sample. Tips that did not break were assigned a breakage time of 10 minutes.

RESULTS

There was a statistically significant difference in breakage as a function of tip type (P = .0002). No EDS 5E tips were observed to break after 10 minutes of instrumentation.

CONCLUSIONS

Based on the results of the investigation, the EDS 5E tip is significantly more resistant to breakage than the other tips tested.

A comparison of dentin cutting efficiency of 4 round-tipped ultrasonic instruments

INTRODUCTION

Ultrasonic instruments are available for a variety of endodontic uses. Few published evaluations exist that compare the dentin cutting efficiency of endodontic ultrasonic tips. Furthermore, previous comparison studies often did not take into account 2 critical factors: clinically relevant downward forces and linear movement during use.

METHODS

Four different round-tipped ultrasonic tips were compared (n = 5 per tip group): BUC-1 (Obtura Spartan, Fenton, MO), BL-2 (B&L Biotech, Bala Cynwyd, PA), BL-3 (B&L Biotech), and START-X #2 (Dentsply Maillefer, Ballaigues, Switzerland). The tips were attached to a testing apparatus that applied a 15-g axial force and a linear movement during instrumentation of a human dentin specimen. Instrumentation was completed at the manufacturers' recommended power settings, and 3 of the tips were also compared at an equal power setting. Instrumentation consisted of 20-second cycles for a total of 6 minutes. Dentin specimens were weighed at baseline and after 2, 4, and 6 minutes of instrumentation. The dentin cutting efficiency was measured by the change in weight of dentin specimens to the nearest 0.1 mg.

RESULTS

A 1-factor analysis of variance and Tukey post hoc analysis of cumulative dentin removal (after 6 minutes of instrumentation) revealed a statistically significant difference among the 4 ultrasonic tips (P ≤ .0001) at the recommended PS, with the BUC-1 tip removing significantly more dentin across time. At an equal power setting, the BUC-1 was significantly more efficient than the BL-3; no difference was found between the BUC-1 and the BL-2.

CONCLUSIONS

Within the limits of this study, the BUC-1 showed the greatest dentin removal. Adding a linear movement and a clinically relevant axial force allows better generalization to clinical applications.

A comparison of the dentin cutting efficiency of 4 pointed ultrasonic tips

INTRODUCTION

Pointed ultrasonic tips can be used for several applications including troughing around intracanal obstructions. With the variety of pointed ultrasonic tips available, the purpose of this in vitro investigation was to compare the dentin cutting efficiency of 4 commonly used pointed ultrasonic tips.

METHODS

The ultrasonic tips (n = 5 tips/group) included in the study were the following: CPR-3D (Obtura Spartan, Algonquin, IL), BL 6A (B&L Biotech, Bala Cynwyd, PA), PUENDO2 (Dentsply Tulsa Dental Specialties, Tulsa, OK), and WH1 (eie2, San Diego, CA). The tips were attached to a testing apparatus that produced linear movement and a 15-g axial force during instrumentation of a human dentin specimen. For all tips, instrumentation was completed at the same power setting, which fell within the power setting range recommended by each manufacturer. Dentin specimens were weighed at baseline and after 6 minutes of instrumentation to measure dentin loss to the nearest 0.01 mg. A qualitative analysis of the shape and surface topography of new and used ultrasonic tips was performed via scanning electron microscopy.

RESULTS

A 1-factor analysis of variance and Tukey post hoc analysis of dentin removal revealed a statistically significant difference between the 4 ultrasonic tips (P < .05). The CPR-3D removed more dentin than the other 3 tips, whereas the BL 6A removed more dentin than the WH1. Scanning electron microscopic analysis revealed the CPR-3D as having the least change to tip shape and topography as compared with the other tips.

CONCLUSIONS

Within the limits of this study, CPR-3D showed the greatest dentin removal, which may be linked to the stability of the CPR-3D tip shape and topography.