title: Root deformation during root-end preparation.
abstract: Ultrasonic root-end preparation techniques have recently been introduced and revolutionized the field of endodontic surgery. However, several reports claimed that there was an increasing incidence of crack formation after ultrasonic root-end preparation. As yet, little work has focused on the root deformation during root-end preparation. Thus, the purpose of this investigation was to measure the amount of root deformation during root-end preparation with the use of microhandpiece and ultrasonic systems by using strain gauge methods, and simultaneously to detect any cracks with the aid of the stereomicroscope, stain, and an image processing system. The results demonstrated the ultrasonic instrumentation produced significantly greater strain on average than that generated with the microhandpiece system. From the viewpoint of fracture, any technique that could diminish the strain on the root would decrease the likelihood of fracture; however, no crack was observed on any resected surface of roots in this study.
authors.affiliation: Department of Endodontics, School of Dentistry, National Taiwan University, Republic of China.
authors.forename: C P
authors.initials: CP
authors.lastname: Lin
authors.forename: H G
authors.initials: HG
authors.lastname: Chou
authors.forename: R S
authors.initials: RS
authors.lastname: Chen
authors.forename: W H
authors.initials: WH
authors.lastname: Lan
authors.forename: C C
authors.initials: CC
authors.lastname: Hsieh
mesh_terms: D003762:Dental Instruments / Q000009:adverse effects; D003799:Dental Stress Analysis; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008853:Microscopy / Q000379:methods; D012184:Retrograde Obturation / Q000009:adverse effects*; D018915:Root Canal Preparation / Q000009:adverse effects* / Q000295:instrumentation*; D014082:Tooth Fractures / Q000209:etiology*; D014092:Tooth Root / Q000293:injuries*; D014464:Ultrasonic Therapy / Q000009:adverse effects* / Q000295:instrumentation; D014732:Vibration / Q000009:adverse effects