Vertical root fracture resistance and dentinal crack formation of root canal-treated teeth instrumented with different nickel–titanium rotary systems: an in-vitro study

Vertical root fracture resistance and crack formation of root canal-treated teeth restored with different post-luting systems

“…An explanation is that possible dentin defects that could be initiated during root canal instrumentation and lling progressed within the inner core dentin adjacent to the root canal wall and were therefore not detectable on the external root surface. Nickel-titanium les with a smaller le taper (4%) were used, as larger le tapers have been shown to reduce the VRF resistance of root canal-lled teeth [5]. In addition, studies showed that single-cone lling techniques like the one used in this study reduce the incidence of dentin defects compared to lateral compaction of gutta percha [4,5].…”

“…Many studies performed fracture resistance measurements and analyses on root canal-treated or postrestored teeth that had been decoronated [5,6,13,21]. From a clinical perspective, however, the results should be interpreted with caution since a coronal restoration could lead to a more favorable stress distribution.…”

“…Nickel-titanium les with a smaller le taper (4%) were used, as larger le tapers have been shown to reduce the VRF resistance of root canal-lled teeth [5]. In addition, studies showed that single-cone lling techniques like the one used in this study reduce the incidence of dentin defects compared to lateral compaction of gutta percha [4,5]. The incidence of dentin defects increased with post space preparation as the root canal wall is further reduced and the inner core dentin with a lower Young's modulus than the more mineralized outer dentin is removed [4,6,27].…”

“…The VRF prevalence was signi cantly higher when a post was placed than in root canaltreated teeth without post [3]. Root canal treatment and post space preparation can damage the root dentin and lead to incomplete cracks or craze lines that can develop into VRF [4][5][6]. Research agrees that root canal-treated teeth cannot be reinforced with cemented metal posts and adhesively luted berreinforced composite (FRC) posts are a promising technique for reinforcing teeth [7][8][9][10].…”

Cone-beam computed tomography diagnosis and nonsurgical endodontic management of a taurodontic mandibular first premolar with two roots and four canals: A rare case report

“…Endodontic files with greater taper will result in excessive removal of the dentinal tooth structure, increase the likelihood of strip perforations, and subsequently lead to vertical root fractures in future. [ 17 18 ] Considering that the present case consisted of four root canals, all canals were shaped to size 25 with 4% taper rotary files for a more conservative approach. Furthermore, a bioceramic-based root canal sealer was used in the current case due to its excellent bioactivity, biocompatibility, and sealing capacity in the root canals, as a hermetic seal is warranted for an excellent long-term prognosis of endodontically treated teeth.…”