The effect of different posts on fracture strength of roots with vertical fracture and re-attached fragments

Abstract

The aim of this in vitro study was to test the effect of different post systems on fracture strength of roots with re-attached fragments. Root canals of eighty extracted single-rooted human teeth were instrumented (ProFile) and randomly divided into two groups. The roots in the first group were vertically cracked, and the fragments were re-attached using Super Bond C&B (Sun Medical, Tokya, Japan). The roots in the second group were kept sound. Obturation of the roots was performed with MetaSEAL (Sun Medical) and gutta-percha. Post spaces were prepared, and the roots were restored with one of the followings: UniCore (Ultradent), Everstick (Stick Tech), Ribbond (Ribbond), ParaPost (Coltene/Whaledent) (n = 10). Four mm high build-ups were created (Clearfil DC Bond Core; Kuraray, Tokyo, Japan). Compressive loading of the samples was performed after 24 h (1 mm min(-1)). Mean load necessary to fracture each sample was recorded (Newton) and statistically analysed (One-way anova, t-tests). ParaPost showed the highest fracture strength among the roots with re-attached fragments (P < 0.05). UniCore and ParaPost systems showed similar fracture strength in the sound roots (P > 0.05). Re-attached fragments significantly reduced the fracture strength of roots in UniCore group (P = 0.000). Ribbond post showed mostly repairable fractures. Metal post (ParaPost) showed the highest fracture strength in the roots with re-attached fragments; however, fracture pattern was 41% non-repairable. Re-attached fragments significantly reduced the fracture strength of the roots in UniCore group. Prefabricated posts showed similar fracture strength in the sound roots. Customized post systems EverStick and Ribbond showed mostly repairable failure after loading in sound roots or roots with re-attached fragments.

Cracked tooth diagnosis and treatment: An alternative paradigm

“…A root fracture is a fracture of a stress plane contained within only one root, such that complete fracture of the stress plane would not result in disconnection of one root from another [ Figure 10 ]. Root fractures,[ 3 48 ] which are often catastrophic fractures,[ 49 ] can result from caries in root structure or from roots containing intra-canal retainers[ 2 50 ] where the tooth lacks ferrule tooth structure, which results in a post putting more stress on the root. [ 51 52 ] Roots can also be fractured via use of excessive pressure while obturating root canals;[ 53 54 55 56 ] using excessive vertical forces to push a peeso reamer into a root while making a postspace, particularly if the peeso reamer is too wide in diameter compared to the diameter of the canal; skipping sizes of peeso reamers while making a postspace, such as moving from a #1 peeso reamer directly to a #3 peeso reamer, particularly when preparing postspaces in thin roots, which are common with premolars or mandibular incisors; or radicular micro-cracks[ 45 57 ] created during apico-ectomy procedures using ultrasonic retro-tips.…”

Effects of NaOCl, EDTA and MTAD when applied to dentine on stress distribution in post‐restored roots with flared canals

“…Polyethylene fibre post–core systems are reported to retain all the remaining root structure in the sound roots and therefore can be considered as appropriate materials for the restoration of the roots with thin walls (Ozcopur et al . ).…”

“…These systems generally involve the use of woven polyethylene or glass fibre to create an endodontic post and core (Eskitas ßcio glu et al 2002). Polyethylene fibre post-core systems are reported to retain all the remaining root structure in the sound roots and therefore can be considered as appropriate materials for the restoration of the roots with thin walls (Ozcopur et al 2010).…”

Fracture resistance of roots filled with three different obturation techniques

“…Coronal reinforcement has been suggested with adhesive dental materials (7,14), crown placements (11,15), or fiber posts (15,16) to prevent unfavorable fractures after obturation. However, in some cases, even properly restored teeth may fracture.…”