{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,1]],"date-time":"2026-09-01T06:16:33Z","timestamp":1788243393169,"version":"build-2803163510"},"reference-count":18,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2026,9,1]],"date-time":"2026-09-01T00:00:00Z","timestamp":1788220800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Dent. J.","Dentistry Journal"],"abstract":"<jats:p>Background\/Objectives: Dental needles are used routinely for local anaesthesia, but repeated insertion, needle selection, and operator handling may all compromise tip integrity. This study assessed bevel deformation, biological debris, and manual bending in used dental needles collected during undergraduate clinical practice. Their associations with needle dimensions, insertion frequency, injection technique, and operator seniority were also examined. Methods: 192 discarded needles were collected from fourth-, fifth-, and sixth-year students and dental interns after routine local anaesthesia procedures at an academic dental hospital. Each needle was examined under stereomicroscopy. Needle bevels were classified as intact, outward bending, or inward bending; biological debris and manual bending were also recorded. Predictors of bevel deformation were identified by multivariable logistic regression. Results: Bevel deformation was present in 93 of 192 needles. Thirty-gauge needles showed higher odds of deformation than 27-gauge needles (OR = 2.54, p = 0.004), and each additional insertion further increased the odds (OR = 1.98, p = 0.016); once gauge was accounted for, needle length was not an independent predictor. Intended bone contact showed no association with deformation. Outward bending predominated among deformed tips (63.4% vs. 36.6% inward), and biological debris was detected on 16.1% of needles. Manual bending was more frequent among interns than students (OR = 3.67, p = 0.007). Conclusions: Used dental needles frequently exhibited bevel deformation, particularly with 30-gauge needles and after repeated insertions. The occurrence of deformation even in the absence of intentional bone contact further supports strict single-use practices and careful needle handling during local anaesthesia. Although the higher frequency of manual needle bending observed among interns should be interpreted cautiously, this finding highlights a potential area for targeted operator training and further investigation.<\/jats:p>","DOI":"10.3390\/dj14090544","type":"journal-article","created":{"date-parts":[[2026,9,1]],"date-time":"2026-09-01T05:45:13Z","timestamp":1788241513000},"page":"544","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Predictors of Dental Needle Bevel Deformation: Gauge, Insertion Frequency, and Length as Key Determinants"],"prefix":"10.3390","volume":"14","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-7720-7737","authenticated-orcid":false,"given":"Osama","family":"Zakaria","sequence":"first","affiliation":[{"name":"Biomedical Dental Sciences Department, College of Dentistry, Imam Abdulrahman Bin Faisal University, P.O. Box 1982, Dammam 31441, Saudi Arabia"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,9,1]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"3","DOI":"10.1007\/s00784-010-0442-6","article-title":"Needle breakage during local anesthesia in the oral cavity-a retrospective of the last 50 years with guidelines for treatment and prevention","volume":"15","author":"Augello","year":"2011","journal-title":"Clin. Oral Investig."},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Cirulli, N., Patano, A., Palmieri, G., Di Pede, C., Settanni, V., Piras, F., Inchingolo, A.D., Mancini, A., Rapone, B., and Malcangi, G. (2023). Needle fracture in pterygomandibular space during loco-regional dental anesthesia: A systematic review. Appl. Sci., 13.","DOI":"10.3390\/app13074421"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"1517","DOI":"10.14219\/jada.archive.2009.0103","article-title":"Broken local anesthetic needles: A case series of 16 patients, with recommendations","volume":"140","author":"Pogrel","year":"2009","journal-title":"J. Am. Dent. Assoc."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"433","DOI":"10.1007\/s10006-022-01078-7","article-title":"Observational and descriptive analysis of broken dental needles: A case series","volume":"27","author":"Sandre","year":"2023","journal-title":"Oral Maxillofac. Surg."},{"key":"ref_5","unstructured":"Malamed, S.F. (2020). Handbook of Local Anesthesia, Elsevier. [7th ed.]."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"370","DOI":"10.12968\/denu.2003.30.7.370","article-title":"An investigation of the effect on 27-gauge needle tips following a single local anaesthetic injection","volume":"30","author":"Rout","year":"2003","journal-title":"Dent. Update"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"585","DOI":"10.1016\/0030-4220(94)90315-8","article-title":"Barbed needle and inexplicable paresthesias and trismus after dental regional anesthesia","volume":"77","author":"Stacy","year":"1994","journal-title":"Oral Surg. Oral Med. Oral Pathol."},{"key":"ref_8","first-page":"1","article-title":"Bevel tip deformation in new and used dental needles","volume":"3","author":"Masuoka","year":"2015","journal-title":"Microsc. Res."},{"key":"ref_9","unstructured":"(2016). Stainless Steel Needle Tubing for the Manufacture of Medical Devices\u2014Requirements and Test Methods (Standard No. ISO 9626:2016)."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"170","DOI":"10.1007\/s00784-024-05546-0","article-title":"The bevel effect: A prospective, randomized investigation into needle design in dental intraligamentary anesthesia","volume":"28","author":"Staedt","year":"2024","journal-title":"Clin. Oral Investig."},{"key":"ref_11","first-page":"48","article-title":"Needle tip deformation after PDL and intraseptal dental local anesthesia","volume":"2","author":"Kuzin","year":"2014","journal-title":"J. Head Neck Physicians Surg."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"164","DOI":"10.1016\/j.jdent.2012.10.016","article-title":"An in vitro investigation of the effect of bevel design on the penetration and withdrawal forces of dental needles","volume":"41","author":"Steele","year":"2013","journal-title":"J. Dent."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"1484","DOI":"10.1016\/j.ijom.2017.06.013","article-title":"Influence of needle bevel design on injection pain and needle deformation in dental local infiltration anaesthesia-randomized clinical trial","volume":"46","author":"Dau","year":"2017","journal-title":"Int. J. Oral Maxillofac. Surg."},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"Jeng, P.Y., Yang, C.M., Kao, C.T., Kuo, M.H., Chuang, S.K., and Jeng, J.H. (J. Dent. Sci., 2025). Needle breakage during dental anesthesia: Management strategies and its associated preventive measures, J. Dent. Sci., in press.","DOI":"10.1016\/j.jds.2025.12.007"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"325","DOI":"10.1111\/aej.12361","article-title":"Evaluation of bevelled needle tip deformation with dental inferior alveolar nerve blocks","volume":"45","author":"Skapetis","year":"2019","journal-title":"Aust. Endod. J."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"e29","DOI":"10.4317\/jced.61784","article-title":"The effect of replacing dental needles between subsequent inferior alveolar nerve blocks on pain and trismus-a double-blinded, randomised split-mouth study","volume":"17","author":"Skapetis","year":"2025","journal-title":"J. Clin. Exp. Dent."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"458","DOI":"10.4103\/JCDE.JCDE_140_24","article-title":"Pulp regeneration treatment using different bioactive materials in permanent teeth of pediatric subjects","volume":"27","author":"Abdellatif","year":"2024","journal-title":"J. Conserv. Dent. Endod."},{"key":"ref_18","first-page":"E317","article-title":"Comparison of two needle models in terms of bevel deformation during truncal block of the inferior alveolar nerve","volume":"12","year":"2007","journal-title":"Med. Oral Patol. Oral Cir. Bucal"}],"container-title":["Dentistry Journal"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2304-6767\/14\/9\/544\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,9,1]],"date-time":"2026-09-01T06:02:57Z","timestamp":1788242577000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2304-6767\/14\/9\/544"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,9,1]]},"references-count":18,"journal-issue":{"issue":"9","published-online":{"date-parts":[[2026,9]]}},"alternative-id":["dj14090544"],"URL":"https:\/\/doi.org\/10.3390\/dj14090544","relation":{},"ISSN":["2304-6767"],"issn-type":[{"value":"2304-6767","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,9,1]]}}}