Fiber Post adaptation when using root canal shaping NiTi files

One of the most difficult steps when restoring endodontic treated teeth is the post space preparation: a bad post space preparation can occur and induce irreversible damage to the tooth.

Objectives: evaluation of adaptation of two different fibre posts after shaping the root canal by two different NiTi rotary files.

Methods: 40 healthy teeth, freshly extracted were selected. Twenty root canals were shaped using RaCe System (FKG, La Chaud de Fond, Switzerland) and twenty using Protaper system (Dentsply-Maillefer, Ballaigues, Switzerland). Peerless post System (Sybron Endo, USA) and DT post system (Dentsply, USA) were fixed into the root canal using an impression paste, without post space preparation. After embedding roots into an epoxy resin and longitudinal cutting, the adaptation of posts was assessed by measuring the length of penetration and the thickness of “sealer”. Statistical analyses to compare post adaptation were made using non parametric tests.

Results: Regarding the length of post penetration, there is a statistical significant difference between the different posts when different root canal shaping instruments are used (p=0,013). When using RaCe rotary files, penetration length of Peerless posts is greater than with DT posts. There is no statistical significant difference for the thickness “sealer” at the tip (p=0,972) and at 3mm from the tip of the post (p=0,2344), but at the ECJ, there is a statistical significant difference (p=0,011). The “sealer” is less thick (p=0,0073) with Peerless Posts than with DT posts when root canal is shaped by Protaper system, and thicker (p=0,0008), when using Peerless posts comparing RaCe shaping and Protaper shaping.

Conclusion: In the conditions of this experimentation, the post space preparation with specific drills is not necessary if root canal shaping is preformed with RaCe or Protaper NiTi rotary files and when Peerless posts or DT Posts are used.