Title Needle Fractures During Local Anesthetic Delivery for Dental Procedures is a Rare Occurrence
Clinical Question What is the incidence of needle fracture during dental nerve blocks?
Clinical Bottom Line The frequency of needle breakage during dental nerve blocks is rare. Factors that increase the potential for breakage include: giving an Inferior Alveolar nerve block, using a 30 gauge short needle, having the patient move, burying the needle in soft tissue up to the hub, or placing a bend.
Best Evidence  
PubMed ID Author / Year Patient Group Study type
(level of evidence)
19955070Pogrel/2009Dental School PatientsCase Series
Key resultsThe study was conducted over a 25 year period at a United States dental school in California. During the 25 year period, 16 cases of needle fractures were reported. 15 of the 16 reported cases involved the provider giving an Inferior Alveolar (IA) nerve block. 13 breakages were recorded with the use of a 30 gauge (usually short) needle. Additionally, 9 of the 13 dentists who used a 30 gauge needle, admitted to bending it prior to inserting it into soft tissue; 5 of the 9 dentists stated that the patient moved while the needle was being repositioned as they had not made contact with mandibular bone. Those 5 cases involved pediatric patients who were younger than 10 years of age. The author went on to extrapolate that if one considers the amount of IA injections given on a daily basis by the 11,200 dentists in Northern California alone, they would account for over 14 million injections a year. From his rough estimate, he believes that there may be only one needle fracture a year per 14 million IA injections in his area alone. He then concluded that a needle fracture in conjunction with delivering a dental block is a rare event.
20625783Augello/2011Dental patientsLiterature Review
Key resultsThis study conducted an analysis of literature of the last 50 years in addition to the authors' own cases. A systematic, multilingual review of medical literature from 1900 until today was conducted and information was evaluated systematically. There were 26 reports documenting 64 needle fractures from 1966-2011. 23 patients were under 16 years of age (yoa), and 16 were over 40 yoa. The average age was 28, with a span of 3-71 yoa. 70% of the fractures involved an IA block(45). In the seven known causes of fracture, 6 were due to sudden patient movement and one due to provider movement. In another examination of 34 patients, the needle size was discovered to be a major contributing risk factor. 23 patients (68%) who were given an IA injection with a 30G needle, had the needle dislodge from the syringe. The author concluded that needle fracture is mainly a problem due to inadequate technique and/or the use of too small of a needle gauge. The authors then provide some guidelines to the clinician if they do experience a needle separation. If a needle fractures, it should be removed surgically under general anesthesia. To localize the fragment, use of either multi-plane X-rays or fluoroscopy with at least two reference needles in place or of three-dimensional CT scans is recommended, depending on availability.
Evidence Search The following search strategy was used in PubMed: Needle breaks, Dental Local Anesthesia
Comments on
The Evidence
This study followed novice dentists during their training over the course of a 25 year period. The number of fractures reported may not be an accurate representation of what exists in the experienced dental professional clinics. There is also no way of quantifying the actual number of injections given to generate an accurate percentage of needle fractures.
Applicability This study is pertinent to anyone who gives dental blocks: Physicians, Dentists, NP, and Dental Hygienists. While a needle breaking during the course of administering local anesthesia is a rarity, it appears that clinicians who follow a few simple guidelines can minimize the potential for a separated needle: Avoid using a 30 gauge needle for IA blocks, avoid short needles, do not bend your needle, and anticipate any abrupt movements on younger patients who appear to be apprehensive. Should a clinician experience a needle fracture they should have the patient seen for an evaluation to have the fragment surgically removed under general anesthesia using multi-plane x-rays or fluoroscopy. jada.ada.org/content/130/5/685.long
Specialty (Endodontics) (General Dentistry) (Oral Surgery) (Pediatric Dentistry) (Periodontics) (Prosthodontics) (Restorative Dentistry) (Dental Hygiene)
Keywords Needle fractures, Breaking needles, dental local anesthetics
ID# 2710
Date of submission 05/05/2014
E-mail eric.mediavilla@ucdenver.edu
Author Eric Mediavilla, DDS
Co-author(s) e-mail
Faculty mentor
Faculty mentor e-mail
Basic Science Rationale
(Mechanisms that may account for and/or explain the clinical question, i.e. is the answer to the clinical question consistent with basic biological, physical and/or behavioral science principles, laws and research?)
None available
Comments and Evidence-Based Updates on the CAT
None available