Fracture Resistance of Upper and Lower Incisors Restored with Glass Fiber Reinforced Posts

doi:10.1016/j.joen.2005.09.015

Journal of Endodontics

Volume 32, Issue 4, April 2006, Pages 328-330

https://doi.org/10.1016/j.joen.2005.09.015 Get rights and content

Abstract

The aim of this in vitro study was to evaluate the fracture resistance of upper and lower incisors restored with glass fiber reinforced posts (FRP). There were 32 upper and 32 lower incisors endodontically treated and FRPs were cemented, using pretreated (Rocatec) and non-pretreated posts. Crowns were fabricated and cemented with Ketac-cem or Panavia. Additionally, eight upper and lower incisors with intact natural crowns were used as control groups. Mandibular incisors restored with FRPs attain fracture strengths comparable to those of natural teeth. The fracture strength of all teeth was increased by using Rocatec. Cementation of the crowns using Panavia only increased the fracture strength in upper incisors. Rocatec used to pretreat the posts and crowns cemented using an adhesive cement appear to reduce the risk of clinical failure.

Section snippets

Materials and Methods

Human maxillary and mandibular central incisors were collected and stored in 0.1% thymol-solution. The teeth were cleaned and damaged teeth were discarded. There were 40 mandibular and 40 maxillary incisors that remained in the study and were randomly assigned to eight test groups (four mandibular incisor groups, four maxillary incisor groups) and two control groups (one mandibular and one maxillary incisor control group).

All teeth in the test groups were endodontically treated, radiographic

Results

The fracture strength of control groups ranged from 186.72 N to 397.28 N (300.47 N ± 70.50 N) for mandibular incisors and from 265.00 N to 796.88 N (482.17 N ± 198.41 N) for maxillary incisors. The upper incisor control group displayed significantly higher fracture strengths than the upper incisor test group: Maxillary incisor test group versus maxillary incisors control group, p < 0.001 (Mann-Whitney U-test). In contrast, the lower incisor test group displayed similar fracture strengths to

Discussion

The present study demonstrated that different loading vectors of FRPs, the pretreatment of the posts and the cementation of the crowns all influence the fracture strength.

Tooth-colored posts offer the distinctive advantage of being more esthetic than metal posts, as metal posts might be visible through the more translucent all ceramic restorations and may cause the marginal gingival to appear dark, even with less translucent restorations (6). Additionally, FRPs show low peak stresses inside the

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Cited by (43)

Effect of intraradicular fiber post on the fracture resistance of endodontically treated and restored anterior teeth: A systematic review and meta-analysis
2022, Journal of Prosthetic Dentistry
Citation Excerpt :
Different types of remaining tooth structure were considered. Teeth without ferule were tested in 8 studies,13,23,26-30,33 1-mm ferule in 5 studies,16,27,32,34,38 2-mm ferule in 10 studies,23-25,27-29,31,35,37,39 3-mm ferule in 2 studies,27,36 Class III cavities in 2 studies,7,14 cervical cavities in 1 study,15 only endodontic access in 5 studies,17-20,40 veneer preparations in 3 studies,7,21,22 and crown preparations in 2 studies7,26; 15 studies7,11,13,16,18,20,24,27,28,30,31,35,37,39,40 analyzed the failure mode of the specimens with different classifications of failure. Some studies classified the fracture mode as per repair possibility11,13,20,30,31,35,37,39 (repairable or unrepairable, favorable or unfavorable, restorable or not restorable), as per fracture extension16,18,24,40 (above or below the cement-enamel junction) and fracture localization7,27,28 (root, coronal, or restoration fracture).
A fiber post is indicated when there is a significant loss of tooth structure and additional support for the restoration is needed. However, whether the use of a glass fiber post affects the fracture susceptibility of the restored anterior teeth is unknown.
The purpose of this systematic review and meta-analysis was to evaluate the fracture resistance of endodontically treated and restored anterior teeth and to answer the research question, “Does the use of a fiber post influence the fracture resistance of endodontically treated and restored anterior teeth compared with alternative restorative treatments?”
A search was performed in PubMed, Scopus, Web of Science, LILACS, BBO, Cochrane Library, and Embase databases without date and/or language restrictions (updated in July, 2020). In vitro studies comparing the fracture strength of endodontically treated and restored anterior teeth with and without fiber posts were included. The risk of bias was evaluated by using the previous meta-analyses of in vitro studies. The results were presented as standardized mean difference with a 95% confidence interval. Statistical heterogeneity of treatment effects between studies was assessed using the Cochran Q test and the I2 inconsistency test, and values greater than 50% were considered indicative of substantial heterogeneity.
After the removal of duplicates and title and abstract screening, 31 studies remained. Seventeen were considered low risk of bias, 10 were medium risk of bias, and 4 were high risk of bias. Meta-analysis comparing control and experimental groups favored the use of a fiber post in endodontically treated teeth with some types of restoration to improve fracture resistance (standardized mean difference= 0.5 [0.08; 0.92]); a glass fiber post was also favored (standardized mean difference=0.92 [0.43; 1.42]); for veneer preparations and teeth with cervical cavities, a fiber post increases the fracture strength (standardized mean difference= 0.74 [0.01; 1.47]; 1.18 [0.35; 2.02], respectively).
The use of glass fiber posts increases the fracture resistance of endodontically treated and restored teeth.
In Vitro Comparison of Porcelain Fused to Metal Crown Retention after Endodontic Access and Subsequent Restoration: Composite, Amalgam, Amalgam with Composite Veneer, and Fiber Post with Composite
2020, Journal of Endodontics
The aim of this study was to evaluate the effect of different access opening restorative materials on crown retention.
Thirty-eight extracted molars were mounted in resin and prepared for porcelain fused to metal (PFM) crowns. The crowns were fabricated and cemented with zinc phosphate, and the force to displace it was measured with a tensile-testing machine before and after endodontic access preparations. The endodontic access area, crown preparation axial wall, and preparation surface area were measured for comparison. The crowns were then recemented, and access openings were restored with either amalgam or composite before displacement force was remeasured. The restorative material was removed from each access opening; access area was measured and restored again (amalgam with composite or fiber post with composite) for displacement force to be remeasured. Paired t test was used to compare the means of displacement between groups. One-way analysis of variance was used to compare the mean outcome measure within the groups.
Statistical analyses showed retention after unfilled access was significantly lower than intact crowns. Amalgam, composite, amalgam + composite, and fiber post + composite increased retention beyond the original value. There was no statistical difference among the different restorative protocols. Qualitative results indicate that the restorative material remains in the crown after displacement regardless of the material used to restore the access.
The results from this study suggest that an endodontic access cavity decreases retention of a PFM crown. However, subsequent restoration with amalgam, composite, amalgam + composite, or post + composite may increase the original retention of the crown.
Micro-computed tomography analysis of gap and void formation in different prefabricated fiber post cementation materials and techniques
2019, Saudi Dental Journal
The study was built around the objective of determining the variances in the gap and void formation around cemented prefabricated fiber posts with two different cementation materials and techniques with micro-computed tomography (μCT).
Standardized acrylic resin roots (N = 40) with prefabricated fiber posts (RelyX™ Fiber Post 3D) were split into four sets (n = 10) based on many types of cementation materials and techniques. In the first group, resin cement (RelyX™ Unicem) was inserted to the canals via root canal tips. In the second group, the same cement was injected, and a microbrush was used to distribute the cement inside the canal. In the third group, dual polymerizing resin cement (MultiCore® Flow) was injected into the canals by using root canal tips. In the fourth group, the same cement was injected, and a microbrush was used to distribute the cement inside the canal. The gap and void formation in the cement and the root canals was evaluated with μCT. IBM SPSS Statistics was used to perform the statistical evaluation, then the Kolmogorov-Smirnov test of normality and Kruskal-Wallis H test to compare these variables with respect to the all groups significant difference (a = 0.05).
The study outlined no difference of significance when evaluating the gap and void formation within the experimental groups (P > 0.05).
There was a certain amount of void and gap formation inside all of the tested specimens. However, no significant variances were found.
Stress generation in mandibular anterior teeth restored with different types of post-and-core at various levels of ferrule
2018, Journal of Prosthetic Dentistry
Pertinent evidence regarding the mechanical integrity of mandibular anterior teeth restored with a post-and-core is limited.
The purpose of this finite element analysis study was to compare the impact of the post type (glass fiber post-and-resin core or cast post-and-core) along with the ferrule effect on the stress fields generated in endodontically treated mandibular lateral incisors and canines.
Three-dimensional models of the segmented mandible were developed. Mandibular incisors and canines with or without a 2-mm circular ferrule and restored with a cast post-and-core or glass fiber post-and-resin core were simulated and subjected to linear elastic static analysis. The principal stress values were calculated. von Mises equivalent stresses were used to evaluate the stress.
Maximum principal stresses in dentin were highest in incisors, with a ferrule. Stress parameters in composite resin core in both incisors and canines were critically close to the tensile failure limit of the core material. Cast post-and-cores cemented in incisors without a ferrule accumulated the highest stresses, exceeding the tensile failure limit of resin-modified glass ionomer cement.
Tooth preparation with a ferrule led to a remarkable rise in stress in the dentin of mandibular incisors but favored the mechanical integrity of the restoration.
Fundamental concepts of enamel and dentin adhesion
2018, Sturdevant’s Art and Science of Operative Dentistry
Void and gap evaluation using microcomputed tomography of different fiber post cementation techniques
2018, Journal of Prosthetic Dentistry
Citation Excerpt :
In the current study, reducing the thickness of the resin cement layer by post relining decreased the void percentage. Some clinical studies have shown that when a thicker resin cement layer is present, more post debonding might occur.10,15-18,26 One reason this can occur is because of volumetric shrinkage and polymerization stress caused by a large amount of resin cement, creating gaps at interfaces and leading to the post debonding.20
Few studies have investigated the voids and gaps produced during the cementation of fiber posts using different techniques.
The purpose of this study was to evaluate and quantify void and gap area formations of different fiber post cementation techniques using microcomputed tomography (μCT).
Standardized endodontically treated acrylic resin roots (N=24) were divided into 4 groups (n=6) according to different fiber posts cemented with the resin cement (FB); fiber posts relined with composite resin followed by cementation (FBR); fiber posts cemented using an ultrasonic device (FBU); and fiber posts relined with composite resin and cemented using an ultrasonic device (FBRU). Each specimen was scanned twice using micro-computed tomography (μCT; empty root, followed by after fiber post cementation). Digital imaging and communications in medicine (DICOM) files were transferred into 3-dimensional (3D) reconstruction software for analysis. Void volume in the cementation system and gap area formation were evaluated; quantitative and qualitative analyses were performed. The data were analyzed using 2-way ANOVA and the Tukey honest significant difference post hoc test (α=.05).
FBR showed a lower percentage of voids than obtained for FB (P<.05). Groups FB, FBU, and FBRU did not show significant difference in void formation (P>.05). No significant differences were found in gap area formations among the experimental groups (P>.05).
The use of a composite resin to reline the fiber post significantly decreased the void formation in the cementation procedure when no ultrasonic device was used. The use of an ultrasonic device did not decrease the percentage of void or gap formation for any technique evaluated.

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Basic research—technologyFracture Resistance of Upper and Lower Incisors Restored with Glass Fiber Reinforced Posts

Abstract

Section snippets

Materials and Methods

Results

Discussion

J Dent

J Prosthet Dent

J Prosthet Dent

J Endod

Biomaterials

J Biomech

J Prosthet Dent

J Endod

J Prosthet Dent

J Prosthet Dent

Basic research—technology
Fracture Resistance of Upper and Lower Incisors Restored with Glass Fiber Reinforced Posts