Effective Factors Including Periodontal Ligament on Vertical Root Fractures

Abstract

The purpose of the present study was to analyze effective factors including periodontal ligament on vertical root fractures (VRFs) . Eighty maxillary central incisors were assigned to eight groups, depending on master apical file (MAF) size, loading point and existence of a simulated periodontal ligament (PDL) . The gutta-percha in the root canal was vertically pressed with a Co-Cr rod using a universal testing machine. An ordinal logistic analysis was employed to determine significant factors. VRFs were observed in 88.8% of the specimens but no horizontal fractures were found. There were three types of VRFs: partial fracture not involving the apex (PF, 41.3% ) , partial fracture involving the apex (AF, 40.0% ) , and complete fracture (CF, 7.5% ) . MAF size significantly affected VRFs (p< 0.05) ; large MAF size exhibited more partial fractures involving the apex. Loading point and existence of PDL did not affect VRFs.

The Effect of Root Preparation Technique and Instrumentation Length on the Development of Apical Root Cracks

“…External reinforcement was avoided using a thin layer of silicone as a simulated periodontal ligament (12)(13)(14). Because an ''exposed'' apex is not uncommon in teeth with chronic apical periodontitis or periapical cysts, the apical 2-to 3-mm portion of the root was exposed to allow for intraoperative image recordings.…”

The effect of working length and root canal preparation technique on crack development in the apical root canal wall

“…In addition, after scaling, no fracture line could be detected on the root surfaces. The silicon layer that simulated a periodontal ligament allowed the limited freedom of movement whilst avoiding external reinforcement (Akkayan & Gü lmez 2002, Okitsu et al 2005. The teeth underwent relative dehydration during polymerization of the acrylic resin, during preparation and during image recordings.…”

Longitudinal tooth cracks and fractures: an update and review

“…The only reported cases of vertical root fracture occurring in non-endodontically treated teeth are in Chinese patients (124,125). Condensation, both lateral and vertical, may cause excessive wedging forces, creating a vertical root fracture (104,111,112,116,119,120,(126)(127)(128)(129)(130). Intraradicular retentive posts have also been implicated (22,62,117,119).…”