Failure analysis of eleven Gates Glidden drills that fractured intraorally during post space preparation. A retrieval analysis study
Abstract The purpose of this study was to determine the failure mechanism of clinically failed Gates Glidden (GG) drills. Eleven retrieved GG drills (sizes #1 to #3) which fractured during root canal preparation were collected and the fracture location was recorded based on macroscopic observation. All fracture surfaces were investigated by a SEM. Then the fractured parts were embedded in acrylic resin and after metallographic preparation, the microstructure and elemental composition was evaluated by SEM and EDS. The Vickers hardness (HV) of all specimens was also determined. Macroscopic examination and SEM analysis showed that the drills failed near the hand piece end by torsional fatigue with fatigue cracks initiating at several locations around the circumference and propagating toward the center. Final fracture followed by a tensile overloading at the central region of cross section. Microstructural analysis, hardness measurements and EDS show that the drills are made of a martensitic stainless steel like AISI 440C. Based on the findings of this study, clinicians should expect fatigue fracture of GG drills that have small size during root canal preparation. Selection of a more fatigue resistant stainless steel alloy and enhancing the instrument design might reduce the incidence of quasi-cleavage fracture on GG drills.
Separation anxiety: Gates-Glidden drills can be hazardous to your health.
INTRODUCTION
Gates-Glidden drills are commonly used during endodontic therapy to aid in the development of straight-line access and coronal enlargement of the root canal. The drills come in various sizes and are typically used in a low-speed air-driven or electric handpiece. As a safety feature to aid in retrieval if separation of the drill occurs during use, Gates-Glidden drills are designed to separate near the hub of the drill to allow for easier retrieval.


METHODS
This case report presents a potentially serious complication associated with the use of Gates-Glidden drills.


RESULTS
A contaminated drill became embedded in the arm of an endodontic resident and required surgical removal.


CONCLUSIONS
Proper office safety precautions can help prevent accidents that may result in serious injury.
Accidental exposures to blood and body fluids among health care workers in dental teaching clinics: a prospective study.
The authors evaluated accidental exposures to blood and body fluids reported to a hotline or to health officials at four dental teaching clinics. The authors used a standard questionnaire to solicit and record data regarding each exposure. During a 63-month period, 428 parenteral exposures to blood or body fluids were documented. Dental students and dental assistants had the highest rates of exposure. Syringe needle injuries were the most common type of exposure, while giving injections, cleaning instruments after procedures and drilling were the activities most frequently associated with exposures.