Fiber-reinforced Composite Posts Research Articles

Metal or fibre posts and root fractures.

Abstract Data sourcesMedline and the OpenThesis database.Study selectionRandomised clinical trials (RCTs) and cohort studies comparing the incidence of root fractures of metallic and fibre-reinforced composite posts with more than five years follow up were considered.Data extraction and synthesisTwo reviewers independently selected studies and assessed study quality. The Cochrane risk of bias tool was used to assess RCTs and the Newcastle-Ottawa Scale for cohort studies. Root fracture leading to tooth extraction was considered a catastrophic failure and defined as the primary outcome. Secondary outcomes (non-catastrophic failures) included endodontic failures, crown dislodgement, post debonding, and post/core fractures. The incidence rate of root fractures and non-catastrophic failures was calculated by dividing the number of events by the period of risk for all included posts during the study period per 1000 post years of follow-up.ResultsFourteen studies (seven RCTs and seven cohorts) were included involving 3202 patients and 4752 posts. In all there were 62 root fractures and 467 non-catastrophic failures.The incidence rate of root fractures (pooled event rate per 1000 post years) for metal posts (four RCTs, four cohorts) was 5.13 (95% CI, 4.05-6.21) compared with 4.78 (95% CI, 4.28-5.27) for the fibre-reinforced posts (five RCTs, three cohorts). The pooled survival rate for was metal posts = 90% (95% CI 85.5- 93.3) compared with 83.9% (95% 67.6-92.8) for fibre-reinforced posts. Heterogeneity between the studies was high. The incidence rate of non-catastrophic failures for metal-based posts (four RCTs, 3 cohorts) was 12.69 (95% CI, 7.90-17.48) per 1000 post years compared with 19.39 (95% CI, 13.21-25.57) for fibre-reinforced posts. Heterogeneity was again important.ConclusionsThe results of the present systematic review based on clinical studies do not support the indication of fibre-reinforced posts based on a reduction of catastrophic failures. However, this review also showed the need for further well designed clinical studies evaluating intra-radicular posts.

Can cement film thickness influence bond strength and fracture resistance of fiber reinforced composite posts?

This study compared the influence of cement film thickness (CFT) on bond strength (BS) and fracture resistance (FR) of fiber-reinforced composite (FRC) posts to root canal. One hundred bovine incisors were used for BS and FR analysis (n = 10) and distributed into five experimental groups according to FRC post diameters (WhitePost DC no. 0.5, no. 1, no. 2, no. 3, no. 4), leading to five different CFTs. The canals were prepared using drill no. 4 provided by the post manufacturer and irrigated with 2.5% NaOCl. After conditioning (24% H2O2/5 min) and silanization, posts were cemented with resin cement. BS was evaluated using push-out test and FR using the compression test at 45°. A stereomicroscope was used to measure CFT and to analyze failure pattern. BS data were subjected to two-way ANOVA and Scheffé test for contrast (α = 0.05); FR data were subjected to one-way ANOVA. BS was significantly affected by CFT, as the most well-adapted post achieved the highest values (p < 0.05). BS was similar for all root thirds. CFT did not affect fracture resistance. No root fractures were observed. A FRC post well adapted to the root canal results in higher BS values. Different CFTs did not influence the FR of teeth restored with FRC posts. The results indicate that post retention is improved when a well-adapted post is used, although this has not been critical to fracture resistance.

Effect of different endodontic sealers on push-out bond strength of fiber posts

Despite the increasing demand for fiber-reinforced composite (FRC) posts, their bonding to root canals is still subject to debate. Endodontic sealers may affect the bond strength between fiber posts and root canal dentin. Aim: To compare the effects of different sealers on fiber post bond strength. Methods: Sixty teeth were divided into 4 groups according to obturation method: GI, gutta-percha without any sealers; GII, gutta-percha and AH26 resin-based sealer; GIII, RealSeal point and RealSeal resin-based sealer, GIV, Guttaflow. Fiber posts were cemented into root canals. Specimens were sectioned, and the bond strength was measured in the middle area. The failure mode was evaluated. Data were analyzed by one-way ANOVA and post hoc test. Results: The highest bond strength was observed in the control group (2.95±1.12), and the least was in the Guttaflow group (1.15±0.78). There was a significant difference between bond strengths of the control and Guttaflow groups and between AH26 and Guttaflow groups (p<0.05). The failure mode was mainly adhesive between dentin and resin cement in all groups. Conclusions: Sealers may have a negative effect on the bond strength of fiber posts to root canal dentin.

Evaluation of the Effect of Sodium Hypochlorite Irrigant on Pull-out Bond Strength of FRC Posts Using Different Resin Cements

Introduction: To evaluate the effects of using sodium hypochlorite irrigant on pull-out bond strength of self-etch and self-adhesive resin cements to dentin. Methods: Sixty intact premolars were decoronated and the root canals were prepared by step-back technique. The teeth were divided into two groups according to the irrigant used during root canal treatment: 5.25% sodium hypochlorite and normal saline. The canals were obturated and after 48 hours storage, 8mm depth post space was prepared with application of normal saline as irrigant. Then, each group was divided into two subgroups depending on the type of the cements used for cementation of fiber reinforced composite (FRC) posts (Panavia F2or Embrace). The pull-out bond strength test was evaluated. Statistical analysis was performed by Two-way AONVA. Results: The type of cement had no statistically significant effect on the bond strength; however, the type of irrigant was statistically effective. There was no interaction between two independent variables. The application of sodium hypochlorite significantly decreased the pull-out bond strength in Embrace cement in comparison with the use of normal saline. Conclusion: The type of irrigants used in endodontic treatment may affect on bond strength of FRC posts cemented by self-adhesive cements.

Fracture Resistance of Roots Restored with Four Different Fiber-Reinforced Composite Posts

Objective: The aim of this study was to compare the resistance to vertical root fracture of root-filled teeth restored with four different fiber-reinforced composite (FRC) post systems and two types of dual-cured resin luting agents. Materials and Methods: Ninety extracted human maxillary central incisors were selected and decoronated to obtain a standardized root length of 14 mm. After root canal obturation, post spaces were prepared to a depth of 10 mm with a No. 3 post drill. The specimens (n = 80) were divided into two groups (n = 40) according to the resin luting agents used: group 1, Variolink II + ExciTE DSC; group 2, RelyX Unicem. These groups were subdivided into four subgroups (n = 10) and restored with one of the following post systems: (a) DT Light, (b) DT Light SL, (c) FRC Postec and (d) Everstick, while the remaining 10 teeth served as controls. The roots were subjected to axial compressive loading using a 2.2-mm-diameter metal sphere in a universal testing machine (0.5 mm/min). A factorial experiment with a single control group (analysis of variance) was used to test the resistance of the specimens. Results: Groups 2a (DT Light + RelyX Unicem; 398.5 N) and 1b (DT Light SL + Variolink II + ExciTE DSC; 431.1 N) had significantly higher resistance to fracture than the control group (334.1 N; p < 0.05). DT Light SL and FRC Postec Plus were more resistant to fracture when Variolink II was used as the luting cement. DT Light and Everstick had higher fracture resistance when they were luted with RelyX Unicem (p < 0.05). Conclusion: The results of this study indicate that the use of quartz fiber posts (DT Light and DT Light SL) with an adhesive luting cement in root-filled teeth may reinforce the root to some extent.

Fracture resistance of upper central incisors restored with different posts and cores.

ObjectivesTo determine and compare the fracture resistance of endodontically treated maxillary central incisors restored with different posts and cores.Materials and MethodsForty-eight upper central incisors were randomly divided into four groups: cast post and core (group 1), fiber-reinforced composite (FRC) post and composite core (group 2), composite post and core (group 3), and controls (group 4). Mesio-distal and bucco-lingual dimensions at 7 and 14 mm from the apex were compared to ensure standardization among the groups. Twelve teeth were prepared for crown restoration (group 4). Teeth in other groups were endodontically treated, decoronated at 14 mm from the apex, and prepared for posts and cores. Resin-based materials were used for cementation in groups 1 and 2. In group 3, composite was used directly to fill the post space and for core build-up. All samples were restored by standard metal crowns using glass ionomer cement, mounted at 135° vertical angle, subjected to thermomechanical aging, and then fractured using a universal testing machine. Kruskal-Wallis and Mann-Whitney U tests were used to analyze the data.ResultsFracture resistance of the groups was as follows: Control (group 4) > cast post and core (group 1) > fiber post and composite core (group 2) > composite post and core (group 3). All samples in groups 2 and 3 fractured in restorable patterns, whereas most (58%) in group 1 were non-restorable.ConclusionsWithin the limitations of this study, FRC posts showed acceptable fracture resistance with favorable fracture patterns for reconstruction of upper central incisors.

Esthetic and functional restoration in a child with S-ECC using Contemporary and Biological Techniques

S-ECC describes dental caries in the primary dentition of young children that occur abruptly, spreading widely and rapidly and is burrowing in nature resulting in early involvement of the dental pulp. The case report presented here is of a 3.5 year old girl with severely decayed maxillary anterior teeth. After pulpectomy, the primary maxillary centrals were reinforced using polyethylene fiber-reinforced composite resin posts and restored using strip crowns and laterals biologically restored using tooth obtained from another patient. The combination of techniques described here offers a simple and effective method for restoring severely decayed primary anterior teeth that reestablishes function and esthetics.

Post-endodontic treatment of incisors and premolars among dental practitioners in Saarland: an interactive Web-based survey.

The aim of the present study was to evaluate the trend of dental practitioners in the federal state of Saarland in Germany in regard to restoring endodontically treated teeth using a Web-based survey. An interactive Web-based survey instrument was developed, including seven clinical scenarios, presented by photographs of natural incisor and premolar with different types of cavities. Following a decision tree adapted to the clinical treatment, questions on different aspects of the post-endodontic treatment were asked. All 615 members of the Saarland Dental Association (SDA) were asked to participate in the survey. A total of 33 % completed the survey. The majority of the participants believed in the reinforcement effect of the ferrule design, as well as the post placement. The vast majority of the responding practitioners (92 %) adapted their treatment strategies to a high extent to the destruction degree of the endodontically treated tooth. Fiber-reinforced composite (FRC) posts are the most popular prefabricated post type, regardless of the cavity size and tooth localization. Significant differences between the dentists according to the degree of experience were detected only for the use of glass-ionomer cements as core buildup material. The predominant post-endodontic treatment strategies of German dental practitioners are only partly in agreement with the current literature. There is a clear trend toward the increasing use of metal-free post and core materials. Although the participants showed a general adoption of modern materials and techniques, different patterns of post-endodontic treatment were revealed that were not consistent with approaches supported by the literature.

Resting-state activity in the left executive control network is associated with behavioral approach and is increased in substance dependence

Post space size and cement thickness can differ because of variations in root canal morphology, such as an oval shape, and because the entire canal space cannot be included in the post space preparation. As a result, increased cement thickness around the post may affect the bond strength between the post and the dentin.The purpose of this in vitro study was to evaluate the push-out bond strength of fiber-reinforced composite resin posts to root dentin with cement layers of varying thickness.Thirty human premolars were endodontically treated and restored with fiber-reinforced composite resin posts. Post space was prepared using a drill with a 1.5-mm diameter and diameters of 1.25 mm (small [S] group), 1.375 mm (medium [M] group), and 1.5 mm (large [L] group) were cemented. The specimens were sectioned horizontally into 1-mm-thick slices, and the push-out bond strengths of the apical and coronal fragments were evaluated. Bond strength was compared using analysis of variance and 2-sample t tests (α=.05).No significant differences were found in the debonding force and push-out bond strength among fiber-reinforced composite posts of different sizes (P>.05). The mean debonding force and standard deviation of the posts were 25.05 ±9.52 N for the S group, 28.17 ±11.38 N for the M group, and 33.78 ±12.47 N for the L group. The corresponding push-out bond strength values were 3.11 ±1.54 MPa, 3.39 ±1.4 MPa, and 4.15 ±1.75 MPa. The differences in debonding force between the apical (26.43 ±10.72 N) and coronal (31.57 ±12.03 N) areas were not significant (P>.05). However, the differences in push-out bond strength between the apical (4.27 ±1.73 MPa) and coronal areas (2.83 ±1.08 MPa) were significant (P<.05).The widening of post spaces and, consequently, the increased cement thickness do not significantly affect the bond strength of fiber-reinforced composite resin posts to root dentin.

WITHDRAWN: Effect of post space conditioning and luting resin on the retentive strength of fiber-reinforced composite resin posts

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Fracture resistance of endodontically restored, weakened incisors

To test the fracture strength of weakened bovine incisors endodontically treated with mineral trioxide aggregate (MTA), calcium phosphate bone cement (CPBC) or fibre reinforced composite (FRC) posts, and to evaluate the fracture mode. Weakened bovine incisors (n = 75), standardized according to the dentinal wall thickness at the cervical area, were randomly assigned to one control group and three experimental groups. Unfilled teeth were assigned to group 1 (n = 20) and served as control group. Group 2 (n = 17) consisted of teeth filled with MTA. In group 3 (n = 18), the incisors were filled with CPBC and in group 4 (n = 20) with FRC posts. All specimens were subjected to load at a cross-head speed of 60 mm min(-1) until fracture occurred. The initial (IL) and final fracture (FL) loads (N) were recorded, and the failure mode among the different groups was evaluated. anova showed a statistically significant difference in fracture load among the groups. Tukey's test revealed a significant difference for the IL between the control group and the experimental groups with exception of the MTA group. The FL was not significantly different among the experimental groups. A high percentage of favourable fractures was seen in the FRC and CPBC groups. FRC posts and CPBC could be promising materials to strengthen non-vital structurally compromised teeth.

Fracture resistance and failure mode of fatigued endodontically treated teeth restored with fiber-reinforced resin posts and metallic posts in vitro.

Fracture of restored endodontically treated teeth is a common complication. The mechanical properties of post systems may play a role in the incidence of tooth fracture. The purpose of this study was to evaluate in vitro the fracture resistance and pattern of fracture of endodontically treated teeth restored with three different post systems. Posts used were fiber-reinforced composite resin posts (FRC post), custom cast silver-palladium, and nickel-chromium posts and cores. A 3-point bending test was performed to calculate flexural strengths and elastic moduli of the specimens. Sixty extracted human maxillary canines were endodontically treated and divided into three groups (n=20). All-ceramic crowns were fabricated and cemented with Variolink II resin cement. Ten specimens of each group were subjected to a constantly increasing load until fracture. The other 10 specimens were fatigued for 106 cycles in a custom-made fatigue machine. Recorded failure loads and modes were statistically compared with one-way anova and Tukey-HSD tests (α=0.05). The resistance to fracture of teeth restored with FRC posts, composite resin cores, and Empress II crowns was similar to that of teeth restored with cast posts and cores (P=0.162). Supracrestal (above root/level of acrylic resin base) oblique fracture was the predominant mode of fracture associated with teeth restored with FRC posts (70%), while vertical root fractures were more common with teeth restored with cast posts and cores. Teeth restored with the FRC post system did not exhibit vertical root fractures and were less likely to show root fracture. Sixty to 80% of teeth restored with both types of cast posts and cores showed vertical and subcrestal root fractures.

Effect of ultraviolet light irradiation period on bond strengths between fiber-reinforced composite post and core build-up composite resin

The aim of the present study was to characterize the effects of the ultraviolet light (UV) irradiation period on the bond strength of fiber-reinforced composite (FRC) posts to core build-up resin. Three types of FRC posts were prepared using polymethyl methacrylate, urethane dimethacrylate, and epoxy resin. The surfaces of these posts were treated using UV irradiation at a distance of 15 mm for 0 to 600 s. The pull-out bond strength was measured and analyzed with the Dunnett's comparison test (α=0.05). The bond strengths of the post surfaces without irradiation were 6.9 to 7.4 MPa; those after irradiation were 4.2 to 26.1 MPa. The bond strengths significantly increased after 15 to 120-s irradiation. UV irradiation on the FRC posts improved the bond strengths between the FRC posts and core build-up resin regardless of the type of matrix resin.

The Comparison of Shear Bond Strength Between Fibre Reinforced Composite Posts with Three Different Composite Core Materials – An In vitro Study

The aim of this study is to compare the shear bond strength between fiber reinforced composite post with three different composite core materials. The materials used for the study were: 30 maxillary central incisors, pre fabricated fiber reinforced composite post (postec plus posts), Multi-core heavy body, Ti-core, Fluoro-core, Etchant gel, Silane coupling agent, Dentin bonding agent, Standardized gutta percha points, Rely-X dual cure composite resin. A total of 30 human maxillary central incisor were selected for this study. They were divided into three groups of 10 specimens each namely A, B and C. The results obtained were analyzed by using one way analysis (ANOVA) and Tukey Honestly Significant Difference and they showed highest mean shear bond strength for group C when compared with group A and group B. There is no significant difference in the shear bond strength values between group A and group B. The teeth restored with multicore HB showed highest shear bond strength. The teeth restored with Fluoro core showed lowest shear bond strength. No statistically significant difference exists between the shear bond strength values between Ti-core and Fluoro-core.

Retentive bond strength of fiber-reinforced composite posts cemented with different surface treatments

Purpose: This study will evaluate the effectiveness of various pretreatments when fiber-reinforced composite (FRC) post is bonded to endodontically treated tooth with resin cement. Materials and methods: Canal shaping of FRC post (DT Light post, Size 3, Bisco Inc., Schaumburg, IL, USA) was performed on endodontically treated premolars at 1.5 cm from CEJ. Samples were divided into 6 groups of surface treatment after conventional washing and drying to the canal. Total of 24 FRC posts were randomly divided into 6 groups of surface treatment as follows: Group C: control - no surface treatment, Group A: airborne-particle abrasion (Cojet sand, 3M ESPE), Group S: silanization (Bis-silane, Bisco Inc.), Group M: universal primer (Monobond-plus primer, Ivoclar Vivadent Inc.), Group AS: silanization after airborne-particle abrasion, Group AM: universal primer treatment after airborne-particle abrasion. Pretreated fiber posts were cemented with resin-based luting material and photo-polymerized and cut to the thickness of 1 mm. Push-out test using a universal testing machine was performed. Bonding failure strength of post dislodgement was measured and the type of bonding failure was classified. Data were analyzed with Kruskal-Wallis test and multiple comparison groups were performed using Tukey HSD value of rank test (α =0.05). Results: Group AS showed significantly highest bonding strength. Group S, group AM, group A, and group M showed lower bonding strength in order. The control group showed the lowest bonding strength. Conclusion: Surface treatment with silane showed to be the most effective of the surface pretreatment methods for cementation of FRC post. Surface treatment with universal primer showed no significant difference compared with no surface treatment group as for bonding strength. (J Korean Acad Prosthodont 2014;52:113-20)

Cyclic Loading of Incisors Restored with Different Post Systems

Objective: To evaluate the fatigue resistance of different post systems by submitting them to cyclic loading. Methods: Human maxillary central incisors of similar dimensions were decapitated, root filled and embedded in acrylic blocks with simulated periodontal ligaments. Post spaces were prepared to a depth of 8 mm and restored with one of the following prefabricated posts: a 1.5 mm diameter titanium post (Mooser) (A), a 1.7 mm diameter zirconia ceramic post (Cosmopost) (B), a 1.4 diameter quartz fiber post (Aestheti-Plus) (C), and glass fiber posts (FRC Postec) of 1.5 mm (D) and 2.0 mm in diameter (E). All the posts were covered with metal copings, stored in 37°C water for 48 h, and then cyclically loaded with 25 N peak load at a 45° angle to the axial direction in a loading machine (Zwick 1465). Every 250 cycles (0.2 Hz frequency), the peak load was increased by 25 N until failure occurred. The equivalent load was calculated with the formula: Peq=()/1000, where Pi is the peak load, which is repeated for Ni cycles. Results: Failure modes were yielding (A) and post fracture (B-E). ANOVA post hoc Tukey test showed significantly higher mean loading cycles and mean equivalent loads for (A) than for the other post groups (p0.05). Conclusion: For severely damaged upper incisors without ferrule, metal posts demonstrated higher fatigue resistance than fiber-reinforced composite or zirconia posts and thus may be preferable over non-metal posts.

Managment of complex crown root fracture using fibre post - A case report

Coronal fractures of permanent dentition are the most common type of dental injury. If the original tooth fragment is available following fracture, the natural tooth structures can be reattached using adhesive protocols. The development and use of fiber-reinforced composite root canal posts make possible the reattachment of the crown esthetically and reinforce the bonding of teeth fragments to the remaining natural teeth. Root fracture is one of the consequences of dental trauma. Horizontal root fractures are unfortunate accidents that most of the times affect the maxillary central incisors mainly in the middle third of the root nevertheless apical and coronal third fractures are also sometimes reported. A single fracture occurs in most cases and multiple root fracture is a rare finding. This case report presents a clinical technique of reattachment of coronal fragment of maxillary lateral incisor after trauma using direct fiber-reinforced post systems and simultaneously management of the fracture in the middle third of the root using fibre post as a intraradicular splint. Healing was observed at 1 year follow-up examination.

Effects of post surface treatments including Er:YAG laser with different parameters on the pull-out bond strength of the fiber posts

This study aims to evaluate the effects of Er:YAG laser irradiation under different power settings on the pull-out bond strengths of fiber-reinforced composite posts. The crowns of single-rooted 60 teeth were removed by separation and the root canals were cleaned and shaped. Root canals were filled and post spaces were prepared. Sixty fiber posts were divided into five groups according to surface treatment methods as follows: an untreated control group, a sandblasting-coated group, and three groups undergoing surface preparation with Er:YAG laser under three different power settings (150, 300, and 450 mJ at 10 Hz for 60 s at 100-μs pulse duration). After root canal procedures, fiber posts were cemented to the root canal. After all of the specimens were set, pull-out tests were performed using a universal testing machine at a crosshead speed of 2 mm/min. The data were analyzed using one-way ANOVA and Tukey post-hoc test (p < 0.05). The pull-out strength values ranged between 5.26 and 6.76 Mpa. The lowest values were observed in the groups without surface treatment. Surface treatment applied by 4.5-W Er:YAG laser increased the pull-out bond strength compared to the control group (p < 0.05). 4.5-W Er:YAG laser irradiation increased the pull-out bond strength of fiber posts to resin cement.

Efficacy of different treatments of root canal walls on the pull-out bond strength of the fiber posts

The aim of this study was to evaluate the efficacy of different irrigation protocols, including laser, on the retention of the fiber-reinforced composite posts to root canal dentinal walls using pull-out tests. Root canals of 60 single-rooted human teeth were filled and post spaces were prepared. Finally, specimens were divided randomly into five groups, each consisting of 12 specimens as follows: 5% NaOCl (control group), 17% EDTA, ultrasonic with 17% EDTA, single 1.5-W Er:YAG laser application, and the combined use of Er:YAG laser and 17% EDTA. After the root canal procedures, fiber posts were cemented to the root canal. Pull-out tests were performed using a universal testing machine at a crosshead speed of 2 mm/min. The data were analyzed using a one-way ANOVA and Bonferroni post hoc test (p = 0.05). Irradiation by the Er:YAG laser with/without EDTA positively affected the pull-out bond strength (p < 0.001). The pull-out strength was significantly higher in the ultrasonic group than that of the single irrigation with NaOCl or EDTA (p < 0.001). Er:YAG laser irradiation with/without EDTA enhanced the bond strength of fiber posts to root canal dentin walls. Additionally, ultrasonic-EDTA combination increased the bond strength.

Mechanical effect of static loading on endodontically treated teeth restored with fiber‐reinforced posts

The aim of this study was to investigate the mechanical behavior of a dental system built up with fiber-reinforced composite (FRC) endodontic posts with different types of fibers and two cements (the first one used with a primer, the second one without it). Six FRC posts were used. Each system was characterized in terms of structural efficiency under external applied loads similar to masticatory forces. An oblique force was applied and stiffness and maximum load data were obtained. The same test was used for the dentine. The systems were analyzed by scanning electron microscope (SEM) to investigate the surface of the post and inner surface of root canal after failure. The mechanical tests showed that load values in dental systems depend on the post material and used cement. The highest load (281 ± 59 N) was observed for the conical glass fiber posts in the cement without primer. There was a 50 and 85% increase in the maximum load for two of the conical posts with glass fibers and a 229% increase for the carbon fiber posts in the cement without primer as compared with the cement with primer. Moreover, almost all the studied systems showed fracture resistances higher than the typical masticatory loads. The microscopic analysis underlined the good adhesion of the second cement at the interfaces between dentine and post. The mechanical tests confirmed that the strength of the dental systems subjected to masticatory loads was strictly related to the bond at the interface post/cement and cement/dentine.