Evaluation of Cutting Efficiency of Ultrasonic Tips Used in Orthograde Endodontic Treatment

Diamondlike Carbon Surface Treatment Improves the Fatigue Resistance of Ultrasonic Tips

INTRODUCTION

The aim of this study was to compare E1-Irrisonic (Helse Ultrasonics, Ocoee, FL) and Irri Black (Helse Ultrasonics), a novel ultrasonic tip with diamondlike carbon treatment, regarding their design, metallurgy, microhardness, bending resistance, and time to fracture under the oscillatory fatigue test.

METHODS

A total of 17 E1-Irrisonic and 17 Irri Black new ultrasonic tips were selected. The tip geometry and surface finishing were assessed using scanning electron microscopy. The elemental composition was defined by energy-dispersive X-ray spectroscopy. Hardness Knoop was calculated using a microhardness tester. The maximum load required to displace the instrument in 45° was recorded in gram/force, oscillatory fatigue was measured in seconds at the moment of instrument fracture, and the size of the separate fragments was determined in millimeters. The Student t test was used for statistical comparison (α = 5%).

RESULTS

Scanning electron microscopic analyses revealed that E1-Irrisonic had a flat end tip, whereas a noncutting rounded tip was observed in Irri Black. The surface of E1-Irrisonic was smoother than Irri Black, which was irregular. Energy-dispersive X-ray spectroscopic analyses showed that the elemental compositions of the E1-Irrisonic and Irri Black tips were consistent with stainless steel and titanium-aluminum alloys, respectively. Irri Black showed significantly higher bending load resistance, time to fracture under oscillatory motion, and hardness Knoop than the E1-Irrisonic tip (P < .05), whereas the length of fragments was similar (P > .05).

CONCLUSION

Diamondlike carbon treatment improved hardness Knoop and reduced the flexibility of the Irri Black ultrasonic tip, improving its time to fracture under oscillatory motion compared with the nontreated E1-Irrisonic tip.

Ultrasonic Device Complications in Endodontics: An Analysis of Adverse Events From the Food and Drug Administration Manufacturer and User Facility Device Experience

OBJECTIVES

The author conducted a study to determine the frequency and types of adverse events associated with endodontic ultrasonic devices as reported to the U.S. Food and Drug Administration (FDA) Manufacturer and User Facility Device Experience (MAUDE) database.

METHODS

Endodontic ultrasonic device-related adverse events reported to the MAUDE database from January 1, 2016, to October 31, 2020, were accessed and reviewed.

RESULTS

A total of 1258 adverse event reports were submitted to the FDA MAUDE database, as classified under FDA product code ELC (ultrasonic scaler) during the study period. Among these reports, 403 were specific to the dedicated use of the 2 main types of ultrasonic devices used in endodontic treatment: ultrasonic tip devices and irrigation-related devices. Device malfunction-associated events, consisting primarily of device breakage, comprised 393 of the 1258 adverse event reports, whereas the remaining 10 reports were identified as being patient injury-related reports.

CONCLUSIONS

The frequency, root causes, and economic costs of ultrasonic tip device breakage remain largely unstudied. Ultrasonic endodontic device-related adverse events and patient injuries occurring within clinical practice may be underreported at the present time. Consequently, the risks and ultimate impacts to patients from ultrasonic endodontic device breakage, malfunction and unknown cause-related adverse events, and patient injuries during their clinical usage remain largely unknown at the present time. Eight of the 10 patient injury-related reports made to the FDA MAUDE database during the period under study, containing descriptions of varying degrees of injury severity, were associated with an irrigation-related device.

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.

Cutting efficiency of apical preparation using ultrasonic tips with microprojections: confocal laser scanning microscopy study

Objectives

The purpose of this study was to compare the cutting efficiency of a newly developed microprojection tip and a diamond-coated tip under two different engine powers.

Materials and Methods

The apical 3-mm of each root was resected, and root-end preparation was performed with upward and downward pressure using one of the ultrasonic tips, KIS-1D (Obtura Spartan) or JT-5B (B&L Biotech Ltd.). The ultrasonic engine was set to power-1 or -4. Forty teeth were randomly divided into four groups: K1 (KIS-1D / Power-1), J1 (JT-5B / Power-1), K4 (KIS-1D / Power-4), and J4 (JT-5B / Power-4). The total time required for root-end preparation was recorded. All teeth were resected and the apical parts were evaluated for the number and length of cracks using a confocal scanning micrscope. The size of the root-end cavity and the width of the remaining dentin were recorded. The data were statistically analyzed using two-way analysis of variance and a Mann-Whitney test.

Results

There was no significant difference in the time required between the instrument groups, but the power-4 groups showed reduced preparation time for both instrument groups (p < 0.05). The K4 and J4 groups with a power-4 showed a significantly higher crack formation and a longer crack irrespective of the instruments. There was no significant difference in the remaining dentin thickness or any of the parameters after preparation.

Conclusions

Ultrasonic tips with microprojections would be an option to substitute for the conventional ultrasonic tips with a diamond coating with the same clinical efficiency.

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.