Fracture Resistance of Endodontically Treated Maxillary Premolars with a Longer Single Post and Shorter Double Posts of Different Sizes: An In Vitro Study

Effect of pretreatment of root dentin surface with cold atmospheric plasma on improving the bond strength of fiber post and resin cement: In vitro study

INTRODUCTION

Achieving stable adhesion between fiber post and interradicular dentin is a challenging process in the restoration of endodontically treated teeth. This study was conducted to investigate the effect of surface pretreatment with cold atmospheric plasma (CAP) on improving the bond strength between them.

MATERIALS AND METHODS

Forty-eight single-canal mandibular premolars were cut 1 mm above the cementoenamel junction to keep the root length of 14 mm or more. After endodontic treatment and preparation of the post space, the teeth were divided into four groups regarding the pretreatment of dentin surfaces, including normal saline, ethylenediaminetetraacetic acid (EDTA), CAP, and CAP + EDTA groups. The data were analyzed using paired and independent t-test and one-way analysis of variance and the significance level was set at p < .05.

RESULTS

The bond strength was significantly higher in the coronal third than in the apical third in all the groups. Moreover, the bond strength was significantly higher in the CAP + EDTA-treated group. The bond strength increased significantly in the CAP group compared to the normal saline group. In addition, the bond strength increased significantly in the CAP or EDTA groups compared to the control group. The lowest bond strength belonged to the control group (normal saline).

CONCLUSION

The surface pretreatment with CAP (alone or in combination with EDTA) played a significant role in improving the bond strength of fiber post and root canal dentin.

Fracture load assessment of digitally fabricated post and prefabricated fibre post in endodontically treated teeth

BACKGROUND

Endodontically treated teeth are structurally more susceptible to root fractures. Proper tooth restorations with digitally fabricated or fibre post following endodontic therapy is essential to restore function and esthetics.

OBJECTIVE

The aim of this in vitro study is to evaluate the fracture load of digitally fabricated and prefabricated fibre posts in endodontically treated teeth.

METHODS

Sixty extracted human single rooted teeth were selected. The crowns were sectioned at the cement-enamel junction to standardize the remaining root length at 15 mm from the apices. Cleaning, shaping and obturation was done using conventional step back technique to an ISO K-file size 40. The roots were divided into two groups of 30 samples each: Group S: teeth reinforced with digitally fabricated posts; Group F: teeth reinforced with fibre posts. Each group was further divided into three subgroups (S7, S9, S12, F7, F9, F12) based on lengths 7, 9 and 12 mm at which the posts were cemented. Composite resin core was fabricated and prepared to receive a complete metal crown. Universal testing machine was used to measure the compressive load required to fracture the teeth.

RESULTS

The highest fracture resistance of 1532N was observed with fibre posts at 12 mm of post space length followed by digitally fabricated post 1398N at 12 mm, but the difference was not statistically significant.

CONCLUSION

The highest fracture resistance was observed in the teeth restored with fibre posts with 12 mm length and the lowest with digitally fabricated post with 7 mm length. As the length of post increases irrespective of type of post fracture resistance increased.

Fracture Resistance of Endodontically Treated Premolars Reconstructed by Traditional Casting and CAD-CAM Milling Post and Cores

Purpose. Restoration of endodontically treated premolars has always been considered as a challenging procedure. This study compared the fracture strength and mode of failure of root canal treated premolars reconstructed with various post and core systems. Materials and Methods. Twenty healthy extracted premolars were selected and underwent root canal treatment and then randomly assigned into 4 groups (n = 5). The teeth in group 1 restored with amalgam, whereas others reconstructed with post and cores made by cobalt-chromium (Co-Cr) casting (group 2), nonprecious gold (NPG) casting (group 3), or computer-aided design (CAD) and computer-aided manufacturing (CAM) milling (group 4). The force at fracture was measured in a universal testing machine, and the failure mode was recorded as repairable or nonrepairable. Results. ANOVA revealed a significant difference in fracture resistance between groups ( $P=0.001$ ). The control group displayed significantly lower strength than that of the CAD-CAM or CO-Cr groups ( $P<0.05$ ). The CAD-CAM posts were also more resistant to fracture than the NPG group ( $P<0.05$ ). The frequencies of repairable fracture in the control, Co-Cr, NPG, and CAD-CAM groups were 40%, 20%, 20%, and 60%, respectively. The chi-square test revealed no significant difference in the distribution of failure modes between groups ( $P=0.415$ ). Conclusion. The teeth reconstructed with post and cores were more resistant to fracture than those restored with amalgam alone. CAD-CAM milling could be considered as the best system for reconstruction of endodontically treated teeth, as it provided the highest fracture strength with less risk of nonrepairable tooth fracture.

Fracture resistance to treated teeth using known endodontics techniques in Indian patients

Teeth with crown structure less than 50% can be restored. Therefore, it is of interest to evaluate an in vitro efficacy of Zirconia post, Glass fiber post, polyethylene-woven fiber posts, and Quartz posts. Forty eight recently extracted mandibular first premolar teeth were randomly grouped in to 4 different groups with 12 samples in each group. After endodontic treatment samples in all groups underwent post preparation followed by restoration with respective posts. The mean fracture resistance (Newton) were 463.5 ± 14.3 (Group I) 425.2± 23.5 (group II), 410.4± 18.6 (Group 3) and 385.2 ± 14.2 (group 4). Data shows that Zirconia post had highest fracture resistance compared to other tested groups.

Fracture resistance of endodontically-treated maxillary premolars restored with different type of posts and direct composite reconstructions: A systematic review and meta-analysis of in vitro studies

OBJECTIVE

To conduct a systematic review and meta-analysis to assess if the presence of an endodontic post may increase the fracture resistance of endodontically-treated maxillary premolars directly restored with composite.

METHODS

A comprehensive systematic literature search according to the PRISMA statement was conducted to assess in vitro studies including endodontically-treated maxillary premolars, restored with different type of posts supporting direct composite reconstructions. Two groups of meta-analyses were performed using fixed effects model and additional Trial Sequential Analysis (TSA) was carried out. Moreover, risk of bias was conducted and quality of evidence for any performed meta-analysis was assessed using Grading of Recommendations Assessment, Development and Evaluation (GRADE).

RESULTS

Twenty-four articles met the inclusion criteria and 13 studies also underwent quantitative evaluation. Fracture resistance of endodontically-treated premolars restored with fiber posts was significantly less than sound teeth (p value: < 0.00001), however endodontically-treated premolars with a fiber post provided an increase in fracture resistance when compared to equivalent teeth restored without post (p value: 0.003). TSA revealed high power of both meta-analyses. Moderate risk of bias was reported in 23/24 studies; only 1 study showed high risk of bias. GRADE system showed moderate strength of evidence due to the presence of a study with high risk of bias and to wide confidence intervals.

SIGNIFICANCE

Within the limitation of the present systematic review and meta-analysis, it can be concluded that endodontically-treated maxillary premolars restored with a fiber post and direct composite restoration demonstrated increased fracture resistance when compared to equivalent teeth without post.

Need for an alternative method to cement fiber-reinforced posts - A pushout bond strength analysis

Background:

The use of dissimilar materials used as posts, luting agents, and the core often makes the restorative procedure quite complicated, as each material demands its own technical process. Furthermore, it may not necessarily result in better collective physical properties.

Aim:

The aim of this study was to analyze the pushout bond strength of a zirconia-based core buildup material in cementing two fiber posts.

Methods:

Eighty single-rooted mandibular premolars were decoronated, endodontically treated, post space prepared, and randomly assigned to one of the following four groups: carbon fiber post luted with PermaCem 2.0, carbon fiber post luted with LuxaCore Z Dual, glass fiber post luted with PermaCem 2.0, and glass fiber post luted with LuxaCore Z Dual. Pushout bond strength was evaluated in a universal testing machine for each of the 2 ± 0.5 mm sections obtained from the samples (total 160 sections)

Statistical Analysis:

One-way ANOVA and post hoc tests were used for statistical analysis.

Results:

The glass fiber posts cemented with LuxaCore Z showed significantly higher pushout bond strength (P < 0.001).

Conclusion:

LuxaCore Z Dual-core build material was more effective as a luting agent for glass fiber post cementation.