Comparative evaluation of fracture resistance of root canal‑treated premolars with MOD cavities restored using different techniques: An in vitro study (original) (raw)
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European Endodontic Journal
For the root canal treated maxillary premolars with a non-carious cervical lesion (NCCL): • Fracture resistance similar to that of the teeth without NCCL could be achieved if properly restored. • Placing a prefabricated Rely X™ FRC post resulted in a greater fracture resistance than those restored without a post. • No differences could be detected in the fracture resistance and pattern between the use of prefabricated Rely X™ FRC post and elastic GC everStick® FRC post. HIGHLIGHTS Objective: To test the hypothesis that the (i) presence of non-carious cervical lesions (NCCLs) and (ii) type of post system have no effect on the fracture resistance and pattern in endodontically treated maxillary premolars. Methods: Human maxillary first premolars (n=60) with two root canals were randomly allocated into four groups (n=15). Buccal wedge-shaped NCCLs were prepared in 45 teeth specimens. Following root canal treatment, the specimens were randomly divided into (i) composite resin core (CRC); (ii) NCCLs + composite resin core (NCCL+CRC); (iii) NCCLs+prefabricated fibre-reinforced composite post + composite resin core (NCCL+PFRC+CRC); (iv) NCCLs+custom fibre posts + composite resin core (NCCL+CFP+CRC). All specimens were subjected to thermocycling (5°C to 55°C/5000 cycles). The compressive load was applied non-axially to the palatal cusp with a universal testing machine at a crosshead speed of 0.5 mm/min at a 30° angle until fracture. Fracture patterns were examined using a loupe magnification (2.5×) under transillumination. Statistical analyses were performed using non-parametric tests and pairwise comparisons of the load-to-fracture among the groups. Chi-square test was used to analyse the fracture patterns (P=0.05). Results: Fracture resistance of NCCL+PFRC+CRC was significantly higher than NCCL+CRC (P=0.011), while NCCL+CFP+CRC did not show any significant difference when compared to NCCL+CRC (P=0.089). No statistical difference was found between CRC, NCCL+PFRC+CRC and NCCL+CFP+CRC (P=1.000). The frequencies of favourable fracture patterns in descending orders were as follows: CRC (80%), NCCL+CFP+CRC (73%), NCCL+PFRC+CRC (60%), and NCCL+CRC (40%). Chi-square test did not show significant differences in fracture patterns among all groups (P=0.110). Conclusion: Restoration of the endodontically treated maxillary premolars with NCCLs, with or without post, resulted in similar fracture resistance as their counterparts without NCCLs. Placement of a prefabricated fibre-reinforced composite post exhibited greater fracture resistance to the maxillary premolars with restored NCCLs than those without a post.
Effect of post type on the fracture resistance of endodontically treated premolars
MATEC Web of Conferences, 2018
Endodontically treated teeth (ETT) are more susceptible to fracture during mastication. The aim of our study was to investigate the fracture resistance of premolars, restored with different techniques. Eighteen human premolars, extracted for orthodontic or periodontal reasons, were used. Mesio-occlusal cavities were prepared on all of them. They were divided into 3 groups according to the restoration method: with a cemented fiber post (FP), with a cemented metal post (MP) and without a post, but restored with a fiber reinforced composite core (FRC). After thermocycling, their fracture resistance was evaluated in a standard testing machine. The results were analyzed with one-way ANOVA and Tukey Honestly Significant Difference (HSD) tests (p<0.05). The fracture modes were also determined. The MP group showed the lowest fracture resistance rates and the highest number of unrestorable root fractures. In conclusion, teeth restored with FRC cores or FP show better survival rates than those restored with metal posts.
Dental and medical problems
There is no sufficient literature on the effect of post location on endodontically treated premolar teeth with 2 roots. The aim of the study was to evaluate the effect of fiber post location on fracture resistance and failure mode of endodontically treated premolars with 2 roots. Fifty extracted maxillary first premolars with 2 roots were divided randomly into 5 groups. Group 1 was comprised of sound teeth, which received only metal crowns (control). Teeth from groups 2, 3, 4, and 5 were decoronated 2 mm above the cementoenamel junction (CEJ) and were endodontically treated. No post was placed in group 2 teeth. Teeth from groups 3, 4 and 5 were given a fiber post placed in the buccal canal, palatal canal, and both buccal and palatal canals, respectively. All teeth in groups 2, 3, 4, and 5 were built up with composite and full coverage metal crowns. A compressive static load was applied at an angle of 25° to the crowns with a crosshead speed of 0.5 mm/min, until fracture. One-way ana...
Journal of Endodontics, 2009
Introduction: There are different reinforcement methods in restoring root-filled teeth. The aim of this in vitro study was to evaluate the effect of fiber post and cusp coverage on fracture resistance of endodontically treated maxillary premolars directly restored with composite resin. Methods: Seventy-five maxillary premolars were divided into 5 groups (n = 15). Except for the control group (intact teeth), in other groups mesio-occlusodistal (MOD) cavities were prepared after endodontic treatment. In the groups with cusp coverage, both buccal and lingual cusps were reduced up to 2 mm. Then specimens in the experimental groups were prepared as follows: composite resin restoration without post and cusp capping, composite resin restoration without post but with cusp capping, composite resin restoration with post but without cusp capping, and composite resin restoration with post and cusp capping. After finishing and polishing, the specimens were stored in distilled water at 37 C for a week. Subsequent to thermocycling and exertion of compressive forces parallel to the long axes of the teeth at a strain rate of 2 mm/min, data were analyzed by using oneway analysis of variance and c 2 test. Results: There were no significant differences in fracture resistance between the groups (P = .057). However, c 2 test showed statistically significant differences between the groups in failure mode (P < .001). The highest number of favorable fractures was observed in the control group (intact teeth). Conclusions: Root-filled maxillary premolars, restored with direct resin composite with or without fiber post and cusp capping, had similar fracture resistance under static loading. (J Endod 2009;35:1428-1432
Journal of Prosthetic Dentistry, 2011
Based on the results of this study, it is recommended that endodontically treated premolars with fewer than 2 remaining cavity walls be restored with posts prior to restoration with crowns. Statement of problem. It is unclear how the amount of substance loss affects whether the fracture strength of endodontically treated and crowned teeth is increased by post placement. Purpose. The purpose of this in vitro study was to evaluate the influence of glass-fiber post placement on the fracture resistance of endodontically treated premolars with varying degrees of substance loss. Material and methods. Sixty-four extracted and endodontically treated mandibular premolars were divided into 4 test groups (n=16) depending on the number of residual coronal dentin walls that ranged from 3 to zero. Teeth in subgroups were either adhesively restored with composite resin without a post (-) or with an adhesively luted glassfiber post (+). After receiving a 0.8-mm shoulder preparation, providing a ferrule of 0.5 mm, teeth were restored with complete metal crowns, which were cemented with glass ionomer cement. All specimens were subjected to dynamic loading in a masticatory simulator for 1.2 million loading cycles with a nominal load of 49 N at 1.2 Hz combined with thermal cycling (between 5 and 55°C, 30-second dwell time). Then specimens were quasi-statically loaded at 30 degrees in a universal testing machine until fracture. Data were analyzed with 2-way ANOVA, followed by multiple comparisons using Tukey HSD test (α=.05). Results. No specimen failed during masticatory simulation. Mean final fracture resistance ranged from 335.6 ±39.7 N to 1064.9 ±211.8 N. Two-way ANOVA revealed that both the number of residual coronal walls and post placement had a significant influence on the fracture resistance (P<.001). However, pair-wise comparisons of groups showed that in groups with 2 or 3 cavity walls, the post effect was not statistically significant (P=.378 and P=.175, respectively). Conclusions. The fracture resistance of endodontically treated premolars was dependent on the number of residual coronal dentin walls. Placement of a glass-fiber post had a significant influence on the fracture resistance when fewer than 2 cavity walls remained but no significant influence when 2 or 3 walls were present.
Journal of international oral health : JIOH, 2015
Endodontically treated teeth with posts are more prone to fracture. Hence, the purpose of this study was to investigate the in-vitro fracture resistance of devitalized teeth and mode of failure restored with posts of different materials and different lengths. Sixty freshly extracted human mandibular premolars were endodontically treated and then restored with 1 of 2 prefabricated posts: Stainless-steel (SS) and glass-fiber (fiber posts [FP]) with intraradicular lengths of 4, 5 or 10 mm (n = 10). Following core restoration, a static compressive load was applied perpendicular to the long-axis of the teeth. Initial failure of each specimen was recorded in Newton. The mode of failure was also determined radiographically. The data were analyzed using two-way ANOVA and Tukey's post-hoc analysis with Bonferroni adjustment. Analysis indicated significant differences (P < 0.001) among the groups. Among the SS posts, SS/7 (246 N) exhibited the highest failure load and SS/4 (122 N) the ...
Fracture resistance of endodontically treated teeth restored with multiple fiber posts
Dental Materials, 2013
Introduction: The aim of the present study was to evaluate the effects of post space preparations with circular and oval post drills and the placement of oval and circular posts on the fracture strength of roots with oval canals. Methods: Seventy mandibular premolars with oval root canals were decoronated. Fourteen teeth were used as a control group (group 1), and the root canals of the remaining teeth were prepared up to size #30. The root canals were filled, and the samples were randomly divided into 4 experimental groups as follows: post space preparation with circular-shaped drills (group 2), post space preparation with ovalshaped drills (group 3), circular post placement (group 4), and oval post placement (group 5). A fracture strength test was performed on each specimen, and the data were statistically evaluated using 1-way analysis of variance and Tukey post hoc tests. Results: The fracture strengths of the circular posts-placed group were higher than those of the oval post-placed group (P < .001). The post space preparation using ovalshaped drills significantly decreased the fracture strength of the roots compared with the control group (P < .001). Conclusions: Within the limitations of the present study, oval posts did not provide a higher fracture resistance to endodontically treated roots with oval canals compared with circular posts. Therefore, clinicians should be aware that oval posts are similar to circular posts in terms of enhancing the fracture resistance of roots with oval canals.
The purpose of this study was to compare the fracture strength and mode of teeth restored with fiber/titanium post, polyethylene fiber, and adhesive composite. The mesial, distal, and palatal walls of human maxillary molar teeth were removed, so that only the buccal wall remained. Group 1, with caries-free maxillary molars, was used as a positive control group and the remaining groups were restored as follows: group 2, with only adhesive composite; group 3, with polyethylene fiber and adhesive composite; group 4, with fiber post and adhesive composite; group 5, with fiber post, polyethylene fiber, and adhesive composite; group 6, with titanium post and adhesive composite; and group 7, with titanium post, polyethylene fiber, and adhesive composite. A universal testing machine was used for fracture tests. Compres-sive loads were applied at an angle of 90 degrees on the occlusal surface of the specimens at crosshead speed of 1 mm/min until fracture occurred. Kruskal-Wallis and Mann-Whitney U tests were adopted for statistical analysis. The study shows that, based on the fracture strength, the group of teeth that were restored with glass fiber post, polyethylene fiber, and adhesive composite has the most significant improvement over all the other teeth groups. Based on the fracture mode, the teeth groups restored with only glass fiber post, adhesive composite, polyethylene fiber, and adhesive composite have relatively more restorable fractures observed.
Fracture resistance of the permanent restorations for endodontically treated premolars
European Journal of General Dentistry, 2018
Aim: This study aims to compare the fracture strength, fracture pattern, types of fracture involved, and areas of fractured restoration among endodontically treated permanent lower premolars restored with different restorative materials. Materials and Methods: Sixty-nine mature human permanent lower premolars recently extracted for orthodontic, periodontal, or other reasons were selected and divided into three groups (n = 23). Groups 1 and 2 were endodontically treated. Standardized mesio-occlusal distal cavities were then prepared in both Groups 1 and 2. Groups 1 and 2 were restored with amalgam using Nayyar's core technique and glass fiber post with composite resin core, respectively. Group 3 consisted of intact teeth which acted as control group. All teeth were tested under constant occlusal load until fracture occurred using a Universal Testing Machine. Data analysis was carried out using Kruskal–Wallis test complemented by Mann–Whitney test. Results: The mean values of fracture strength were 388.05 N (± 158.09) for Group 1, 588.90 N (± 151.33) for Group 2, and 803.05 N (± 182.23) for Group 3. Kruskal–Wallis test showed significant differences among all three groups in terms of fracture strength. The mean load required to fracture intact teeth in Group 3 was significantly highest, followed by Group 2 (P < 0.01) and finally Group 1 (P < 0.01). Most fractures occurred within the coronal structure and were considered favorable pattern. Besides, majority of the fractures occurred on restorations and particularly at the distal side. Conclusions: Teeth restored with fiber post and composite core resulted in higher fracture resistance than teeth restored with Nayyar's core amalgam restoration. Keywords: Fracture pattern, fracture resistance, glass fiber post, Nayyar's core, post and core technique