Influence of fiber posts on the fracture resistance of endodontically treated premolars with different dental defects

Abstract

This study aimed to evaluate the influence of quartz fiber post placement on the fracture resistance of endodontically treated premolars with different dental defects under dynamic loading. Fifty extracted single-rooted mandibular premolars were randomized into five groups. Each group was prepared according to numbers of residual walls ranged from 0 to 4. Then each group was divided into two subgroups with one restored with quartz fiber posts and the other without posts. In no-post groups, gutta percha point 2 mm below cemento-enamel junction was removed. Composite resin was adapted to the well and used to shape the core directly. Each tooth was restored with a complete metal crown. Dynamic loading was carried out in a masticatory simulator with a nominal load of 50 N at 2 Hz for 300 000 loading cycles. Then a quasi-statically load was applied in a universal testing machine 30° to the long axis with a crosshead speed of 1 mm⋅min−1 until fracture. Data were analyzed with one-way analysis of variance and pairwise comparison (P<0.05). No specimens failed during dynamic loading. The fracture resistance enhanced with the increase of numbers of coronal walls and the differences were significant (P<0.05). Placement of fiber posts had a significant effect when fewer than two walls remained (P<0.05), but it had no significant influence in groups with two, three or four walls (P>0.05). Fiber post did not change failure mode, and the fracture pattern was mainly favorable. More dentin walls need to be retained in clinic. When no less than two walls remained, a fiber post is not always necessary.

Are posts necessary for the restoration of root filled teeth with limited tissue loss? A structured review of laboratory and clinical studies

“…The influence of fibre post insertion on the fracture resistance of root filled premolars with varying degrees of tooth loss, restored with metal crowns and subjected to cyclic loading, was assessed by both Mangold & Kern () and Hou et al . (). The placement of a fibre post significantly improved the fracture resistance of teeth with <2 cavity walls, but had no significant influence in teeth with two or more walls.…”

“…, Hou et al . ). Additional dentine removal is often necessary for post space preparation, which may weaken the tooth.…”

Fracture resistance of teeth with oval canal morphology restored using oval and circular posts

“…The bonding agent (Clearfil SE Bond; Kuraray Medical Inc., Tokyo, Japan) was applied to the post and residual coronal tooth structure and was light polymerized for 20 s. A composite resin (Filtek Ultimate; 3M ESPE) core was incrementally fabricated in 2 mm layers, and each layer was light polymerized for 40 s. After polymerization, a chamfer margin with a height of 6 mm (including 1 mm ferrule) and a convergence angle of approximately 5° was prepared in all samples, similar to a previous study (22). All teeth were restored with cast metal Ni-Cr (Rubyalloy; rubydent, Istanbul, Turkey) full crowns which were constructed to form a standard first mandibular premolar with 8.5 mm height, 7 mm mesio-distal width, and 7.5 mm bucco-lingual width.…”

A Conservative Treatment Approach with Laser Therapy for Complicated Crown Root Fractures of Maxillary Anterior Teeth: A Report on Three Representative Cases of Pediatric Patients

“…34,35 Fiber posts have superior specialties including aesthetic appearance, the similar modulus of elasticity between fiber posts, dentin and resin cements, high tensile strength, good transparency, resistance to corrosion, and they can be removed easily. 36 In the above cases, fiber posts were used and preferred to metal posts.…”