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Objective: The demand for esthetics has increased in today's world and most parents prefer to preserve their children's primary anterior teeth until their natural exfoliation. However, an intracanal post is required to provide retention for reconstruction of severely damaged anterior teeth due to caries or trauma. Various materials and methods may be used for the fabrication of intracanal posts. This study assessed the fracture strength and fracture mode of primary canine teeth reconstructed with prefabricated and customized polyethylene and glass fiber posts., Materials and Methods: This in vitro study evaluated 60 extracted primary canine teeth in four groups (n = 15). After pulpectomy and post space preparation with 4 mm depth, composite resin post, prefabricated glass fiber post (Whitepost), customized glass fiber post (Interlig), or customized polyethylene fiber post (Ribbond) were placed in the root canals to provide retention, and the tooth crown was restored with bulk-fill composite resin. The fracture strength was then measured in a universal testing machine. The fracture mode was also evaluated visually., Results: The mean fracture strength was 22.45 ± 5.06, 33.10 ± 8.5, 30.20 ± 7.33, and 32.61 ± 5.73 N/mm 2 in the composite resin post, Whitepost, Interlig, and Ribbond groups, respectively. The fracture strength was significantly lower in the composite group than in the remaining three groups (p = 0.000). No other significant differences were found (p > 0.05). Also, no significant difference was observed among the study groups in the fracture mode (p = 0.241)., Conclusion: The composite resin post yielded a significantly lower fracture strength than the prefabricated and customized glass and polyethylene fiber posts, but the fracture mode was not significantly different among the four groups., (© 2024 The Author(s). Clinical and Experimental Dental Research published by John Wiley & Sons Ltd.)

Purpose: This study aimed to assess the impact of battery levels in single-peak and multi-peak light-curing units (LCUs) on irradiance, and their effects on glass fiber post push-out bond strength to root dentin and the degree of conversion of dual-cure universal resin cement., Methods and Materials: Sixty bovine roots underwent endodontic treatment and were randomly distributed into 6 groups (n=10), formed by combining two LCUs (single-peak and multipeak) and three battery levels (100%, 50%, and 10%). A spectrophotometer measured irradiance (mW/ cm2) and spectral irradiance (mW/cm2/nm). Push-out bond strength (PBS) tests occurred at three root regions (cervical, middle, and apical), with optical and scanning electron microscopy for failure mode analysis. Degree of conversion (DC) was evaluated across the root regions. Data were analyzed using two-way repeated measures ANOVA and the Tukey HSD test. The Fisher exact test verified failure modes (α=0.05)., Results: As multipeak LCU battery levels decreased, emitted irradiance also diminished, with notable PBS reductions in the apical thirds. Failure modes were influenced by different conditions, primarily exhibiting mixed modes. Battery levels significantly impacted DC in the multipeak LCU, particularly in the cervical region, while the single-peak LCU exhibited DC reduction at the 10% battery level in the cervical region., Conclusions: Emitted irradiance, resin cement DC, and glass fiber post bond strength to root dentin may be influenced by varying cordless LCUs and battery levels., (©Operative Dentistry, 2024.)

Background: This study aimed to assess the accuracy of two different endodontic guides for fiber post removal., Methods: In this in vitro study, 54 maxillary canine fiber posts were mounted on 36 maxillary stone casts; 18 teeth were mounted unilaterally, and 36 teeth were mounted bilaterally. Static endodontic guides were fabricated according to baseline cone-beam computed tomography (CBCT) and intraoral optical scans using Blue Sky software. In the single-sleeve endodontic guides group (SSG), two anterior and two posterior teeth were included in a 5-unit guide. In the double-sleeve endodontic guides group (DSG) group, the guide was passed through the midline to include both canine teeth and extended by 2 teeth posterior to the canine teeth bilaterally (a 10-unit guide). After drilling, postoperative CBCT scans were taken and superimposed on the virtually designed path, and the maximum coronal deviation (MCD) at the marginal entry point of the tooth, maximum apical deviation (MAD) at 10 mm apical to the tooth margin, and maximum angular deflection (MAnD) of the drill were calculated., Results: The mean MCD, MAD, and MAnD were 0.34 mm, 0.6 mm, and 2.32 degrees, respectively, in the SSG and 0.31 mm, 0.7 mm, and 2.37 degrees, respectively, in the DSG. The two groups were not significantly different from each other in terms of MCD (P = 0.573), MAD (P = 0.290), or MAnD (P = 0.896)., Conclusions: The accuracies of the two techniques, the extended double sleeve guide and the single sleeve guide, were comparable and thus DSG may be used for removal of fiber posts in adjacent or distant teeth., (© 2024. The Author(s).)

Objectives: This review was undertaken to answer a controversial clinical question with high-quality evidence: When severely damaged teeth are restored, which type of post (metal or fiber) demonstrates superior clinical performance?, Data Sources: The meta-analysis was conducted according to the guidelines in the Cochrane handbook. Electronic databases (MEDLINE, EMBASE, CENTRAL) and gray literatures were screened up to January 2018. Only randomized controlled trials (RCTs) with follow-up of at least 3 years were included. The quality of included studies was assessed by the Cochrane Collaboration's tool. Meta-analysis compared survival, success, post debonding, and root fracture incidence of teeth restored with fiber and metal posts. The GRADE system (Grading of Recommendations, Assessment, Development and Evaluations) was used to assess the strength of the evidence. Of 1,511 records, 14 full texts were obtained. Only four RCTs with follow-up times of 3 to 7 years met the selection criteria. The methodologic quality of included RCTs was low risk of bias. Fiber posts presented significantly higher survival rates than did metal posts (RR 0.57, 95% CI: 0.33 to 0.97, P = .04), while no difference was observed in success rates, post debonding rates, or root fracture rates. The GRADE assessment indicated a high quality of evidence for survival rates and a moderate quality for success rates., Conclusion: It was concluded that fiber posts displayed higher medium-term (3 to 7 years) overall survival rates than did metal posts when used in the restoration of endodontically treated teeth with no more than two coronal walls remaining.

Purpose: To evaluate the influence of different post systems on the biomechanical behavior of teeth with a severe loss of remaining coronal structure., Materials and Methods: Fifty standardized bovine teeth (n = 10 per group) were restored with: cast post-and-core (CPC), prefabricated metallic post (PFM), parallel glass-fiber post (P-FP), conical glass-fiber post (C-FP), or composite core (no post, CC). The survival rate during thermomechanical challenging (TC), the fracture strength (FS), and failure patterns (FP) were evaluated. Finite element models evaluated the stress distribution after the application of 100 N., Results: All specimens survived TC. Similar FS was observed among post-containing groups. Groups P-FP and CC presented 100% repairable fractures. The von Mises analysis showed the maximum stresses into the root canal in groups restored with metallic posts. Glass-fiber posts and CC presented the maximum stresses at the load contact point. Glass-fiber groups showed lower stresses in the analysis of maximal contact pressure; CPC led to the highest values of contact pressure. The modified von Mises (mvM) stress in dentin did not show differences among groups. Moreover, mvM values did not reach the dentin fracture limit for any group., Conclusions: The type of intracanal post had a relevant influence on the biomechanical behavior of teeth with little remaining coronal structure., (© 2018 by the American College of Prosthodontists.)

Purpose: In clinical prosthetics procedures, including endodontics and post fixation, the presence of a smear layer can reduce the post bond strength. An Er,Cr:YSGG laser, which emits at 2780 nm, can promote a smear-layer-free surface due to the ablation process. Considering these aspects, the purpose of this work was to evaluate the influence of Er,Cr:YSGG laser irradiation using either a radial or an axial fiber tip on the bond strength of three resin cements to the fiber-reinforced composite posts., Materials and Methods: Ninety recently extracted single rooted human teeth had their root canal instrumented and were randomly distributed into nine experimental groups, in which three resin cements (total-etching Variolink II, self-etching Panavia F, and self-adhesive RelyX Unicem Aplicap) and three root canal treatments (no treatment, laser irradiation using the radial fiber tip, laser irradiation using the axial fiber tip) were used. Specimens were then sectioned into three sections (cervical, middle, and apical thirds) with two slices on each section. A push-out test was performed on each slice, and the values were recorded as MPa. The push-out data were analyzed by a Ryan-Joiner normality test followed by a two-way ANOVA test and Tukey pairwise comparison. The statistical analysis was performed on each third section separately, with a 5% significance level., Results: Laser irradiation with axial fiber tip significantly increased the post bond strength of RelyX Unicem Aplicap on middle third of specimens (p < 0.001) when compared to other root canal treatments (unlased or irradiated with radial tip). Considering the Panavia resin cement, laser irradiation with either axial or radial tips promoted a significant increase on the post bond strength of middle third when compared to unlased specimens (p < 0.001); however, laser irradiation did not influence the post bond strength of Variolink resin cement., Conclusions: The use of the Er,Cr:YSGG laser for clinical prosthetics procedures enhances the post bond strength of Panavia and RelyX Unicem Aplicap resin cements, mainly at middle third of roots, and does not interfere with the bond strength of Variolink resin cement. For the RelyX Unicem Aplicap system, the use of axial tip is most advantageous and can be recommended for future clinical application., (© 2017 by the American College of Prosthodontists.)

Statement of Problem: Data on the retention of individually formed fiber-reinforced composite posts (everStick) cemented with self-adhesive cement are lacking., Purpose: The purpose of this in vitro study was to investigate the pull-out strength of 2 different fiber-reinforced composite posts (prefabricated and individually formed) cemented into extracted teeth with self-adhesive resin cement., Material and Methods: Thirty extracted single-rooted human teeth were decoronated, endodontically treated, and prepared with post spaces of equal length. Prepared specimens were divided into 2 groups (n=15 each) based on the type of post: commercially prefabricated fiber posts (GC) and individually formed resin posts (using GC reinforcing fibers). Self-adhesive resin cement (G-CEM LinkAce; GC) was used to cement all posts. Each post was held with moderate pressure, and root surfaces were light polymerized for 20 seconds (650 mW/cm 2 ). After cementation, the specimens were stored in saline solution for 30 days. Treated teeth were kept in water for 24 hours before pull-out testing parallel to the longitudinal axis of the posts. Data were analyzed using the Student t test (α=.05) and the coefficient of variance as the ratio of the standard deviation to the mean., Results: The mean pull-out retention strength was 185.7 ±61.2 N for the prefabricated fiber posts and 98.9 ±56.5 N for the individually formed fiber posts (P=.026)., Conclusions: The prefabricated fiber posts exhibited significantly higher retention forces than the individually formed posts., (Copyright © 2018 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.)

Purpose: To compare two fiber post removal techniques in terms of fracture resistance and time required for post removal., Materials and Methods: Post space was prepared to a 9-mm depth in each root canal. The roots were randomly divided into three groups of 15 specimens each. D.T. Light-Posts were cemented in all groups. In group 1, fiber posts were removed using the D.T. Light-Post-removal kit; in group 2, Start-X stainless-steel ultrasonic tips were used. In group 3, fiber posts were left without removal (the control group). For all groups, fracture resistance (N) value was measured and recorded using a universal testing machine. Times required for fiber post removal were also recorded for the two study groups., Results: There was no significant difference between the control and removal kit groups for fracture resistance values (p = 0.233). The fracture resistance value of the ultrasonic group was found to be significantly lower than that of the control group (p = 0.001) as well as that of the removal kit group (p = 0.032). The fiber post removal time for the ultrasonic group was significantly longer than that for the removal kit group (p < 0.001)., Conclusion: Compared to the removal kit, removal of the fiber posts with an ultrasonic tip decreases the fracture resistance of the roots, although significantly more time is required., (© 2017 by the American College of Prosthodontists.)

Objective: To evaluate the effect of computer aided design and computer aided manufacture (CAD/CAM) one-piece zirconia posts and cores for the restoration of defective teeth., Methods: In the study, 72 defective teeth of 47 patients who had proper root canal therapy were restored with CAD/CAM one-piece zirconia posts and cores. All the ceramic crowns were finally used to restore contour and function of the teeth. The defective teeth were divided into two groups on the basis of the teeth defect degree. Group A: 39 defective teeth presented with three or four coronal residual walls, and group B: 33 defective teeth presented with less than two coronal residual walls. During the clinical observation period, the stability, dislocation of posts and the occurrence of fractures in either teeth or posts and cores were assessed and analyzed with a paired t test(α=0.05). Meanwhile shade matching was conducted between the restored teeth and normal reference teeth, the marginal fitness of the restored teeth were recorded according to the standard of United States Public Health Service (USPHS) and analyzed with descriptive statistics., Results: The average follow up was (65.0±4.8) months. During the observation period, the restorations were examined both clinically and with periapical radiograph. No incidence of teeth fracture or posts and cores complications were observed in both groups, and all CAD/CAM one-piece zirconia posts and cores remained intact with restored teeth. There were no post and core dislodgement or fracture. There was no difference between group A and group B (P>0.05). The restorative effect of CAD/CAM one-piece zirconia posts and cores with all the ceramic crowns were assessed according to the standard of USPHS, and the number of the restored tooth shade matching with level A was 67, and 5 with level B. The rate of shade matching was 93.06%. As the marginal fitness, 64 restored teeth were level A, and 8 with level B. The rate of restorative teeth marginal fitness was 88.89%., Conclusion: CAD/CAM one-piece zirconia posts and cores were successfully used to restore defective teeth and received excellent clinical effect. So, it can be a good choice for defective teeth which need post-cores and crowns restoration.

Post crowns are restorations which utilise the root canal space to improve the retention and resistance form of teeth which lack coronal tooth structure. In recent years there have been significant developments in the materials, systems and evidence-base surrounding the provision of post crowns. This review aims to refresh the general dental practitioner's (GDPs) knowledge of the different factors that must be considered when placing a post crown, and how these factors can help guide the dentist in their decision to provide either a direct or indirect post and core.

The aim of this retrospective study was to investigate the clinical outcome of Dalbo®-Rotex® retention elements in a private practice. The majority of the retention elements was fixed with self-adhesive composite cement, and in almost 40% the exposed root surface was additionally covered with composite. The success rate of 96.3% after 24 months in a total of 50 included patients (response rate 48.5%) demonstrated that a simple and cost-effective fixation of removable dentures using prefabricated, chair-side inserted retention elements is feasible. Maintenance care comprised single or repeated replacement and activation of the female part in 12.3% and 39.4% of the cases, respectively. Fractures were rare, occurring in 3.4% of the cases and more likely in patients with parafunctional habits. Frequent oral hygiene correlated with probing depths up to 3 mm at the maxi- mum, while the risk of greater probing depths associated with less frequent oral hygiene increased by a factor of 2.4. Patients’ assessment of the parameters handling and wearing comfort, chewing ability and prosthesis retention was predominantly positive. Based on the findings of the study, covering of exposed dentin areas with composite resin and regular recall comprising professional cleaning, fluoride application and oral hygiene instruction are recommended.

The purpose of this study was to evaluate the push-out bond strength of two different adhesive cements (total etch and self-adhesive) for glass fiber post (GFP) cementation in simulated, long-term service (thermocycling) when the root canal is treated with chlorhexidine before cementation. One hundred twenty premolar specimens with a single root canal were selected, endodontically treated, and shaped for GFP cementation (n=120). The specimens were randomly placed into one of 12 groups (10 specimens each) according to cement (T = total-etch RelyX ARC or S = self-adhesive RelyX Unicem), treatment with chlorhexidine (N or Y: without or with), and number of thermal cycles (00, 20, or 40: 0, or 20,000 or 40,000 cycles): 1. TN00, 2. TN20, 3. TN40, 4. TY00, 5. TY20, 6. TY40, 7. SN00, 8. SN20, 9. SN40, 10. SY00, 11. SY20, 12. SY40. The root of each specimen was cut perpendicular to the vertical axis, yielding six 1.0 mm-thick sections. A push-out bond strength test was performed followed by statistical analysis using a factorial analysis of variance. Pairwise comparisons of significant factor interactions were adjusted using the Tukey test. Significant differences of push-out bond strengths were found in the four main effects (resin cement [ p<0.0001], treatment with chlorhexidine [ p<0.0001], number of cycles [ p<0.0001], and root third [ p<0.0001]) and all interactions ( p<0.05 for all). Both resin cements produced higher bond strength in the cervical third followed by the middle third, and lower values were detected in the apical third. Additionally, the results suggest that the use of an additional disinfection treatment with chlorhexidine before the cement application produced the highest push-out bond strength regardless of root third. Further, the thermocycling simulation decreased the bond strength for both resin cements long-term when the chlorhexidine was not applied before cementation. However, when the root canal was treated with chlorhexidine and the fiber post was cemented with self-adhesive cement, the bond strength increased after 0, 20,000 and 40,000 cycles.

Context: Light transmission (LT) into deeper areas of the dentin root is limited., Aim: The aim of this study is to perform a quantitative investigation of the radial transmission of light (LT) through different fiber posts and its influence on the Knoop hardness number (KHN) and bond strength (BS) of a dual-cure self-adhesive resin cement at 3 different depths., Materials and Methods: Four types of fiber posts (2 translucent and 2 conventional) were used. LT and KHN analyses were performed in a specially designed matrix, which allowed measurements at 3 different depths. LT was measured using a volt-ampere meter while KHN tests were performed in a microhardness tester. For BS analysis, endodontically treated bovine roots were divided into 4 groups, each group receiving one type of post. After cementation, cross sections of the root were tested for resistance to displacement using a universal testing machine., Statistical Analysis Used:: Statistical analysis was performed by using this ANOVA and Tukey's test., Results: For LT, translucent posts showed significantly higher values at all depths compared to the conventional ones. For all posts, LT decreased at the deeper depths. The KHN results showed no statistical differences among the different posts, regardless of depth. For BS, a translucent post showed the highest values, and comparative analyses between the different depths of posts also showed statistically significant differences while comparisons among the different depths of the same post showed no differences., Conclusions: LT depended on the type of post and on depth. The type of post did not significantly influence the cement KHN. A translucent post showed higher BS in pooled data., Competing Interests: There are no conflicts of interest.

Introduction: Glass fibre posts that are newer and have better properties are gaining more popularity than metal posts. However, there is no consensus about the optimal cementation depth of glass fibre posts. In our study, we have attempted to assess fracture resistance of roots restored with glass fibre posts cemented at different root depths., Materials and Methods: Specimens were formed with peeso reamers and a special reamer adapted for the cementation of glass fiber posts at different depths. Glass fibre posts were cemented using self-etching cement: in group 1 - at the depth of 2/3 of the working length of the root canal (11 mm), in group 2 - at the depth of 1/2 of the working length of the root canal (7.5 mm) and in group 3 - at the depth of 1/3 of the working length of the root canal (5 mm). Dental roots were standardized by preparing their walls to equal measurements with a mill. Specimens were embedded on a metal plate at a 45° angle and were vertically pressed with a hydraulic press in buccolingual direction. Fracture force was recorded in Newton (N) to the breaking point., Results: After data analyses with ANOVA and T-test software, the null hypothesis was confirmed: there was no statistically significant difference among the results of all 3 groups (P >0.05)., Conclusion: The cementation depth of the glass fibre posts that we studied has no influence on root fracture resistance.

Introduction: This is the first long-term randomized controlled trial to evaluate dentin-like glass fiber posts (GFPs) compared with rather rigid titanium posts (TPs) for post-endodontic restoration of severely damaged endodontically treated teeth with 2 or fewer remaining cavity walls., Methods: Ninety-one subjects in need of post-endodontic restorations were randomly assigned to receive either a tapered GFP (n = 45) or TP (n = 46). Posts were adhesively luted by using self-adhesive resin cement, followed by composite core build-up and preparation of 2-mm ferrule design. Primary end point was loss of restoration for any reason. Kaplan-Meier curves were constructed, and log-rank test was calculated (P < .05)., Results: After a follow-up of 132 months, 17 GFP and 20 TP restorations survived, and 19 failed (12 GFP, 7 TP). Failure modes for GFP were root fracture (n = 4), core fracture (n = 1), secondary caries (n = 1), endodontic failure (n = 2), extraction because of tooth mobility grade III associated with insufficient design of removable partial denture (n = 1), tooth fracture (n = 1), and changes in treatment plan (n = 2); failure modes for TP were endodontic failure (n = 5), root fracture (n = 1), and 1 extraction for other reasons. Cumulative survival probability was 58.7% for GFP and 74.2% for TP., Conclusions: When using self-adhesively luted prefabricated posts, resin composite core build-up, and 2-mm ferrule to reconstruct severely damaged endodontically treated teeth, tooth survival is not influenced by post rigidity. Survival decreased rapidly after 8 years of observation in both groups., (Copyright © 2017 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

Statement of Problem: Endodontically treated teeth with Class III restorations show reduced fracture resistance. The placement of glass fiber posts may affect fracture resistance and should be further evaluated., Purpose: The purpose of this in vitro study was to evaluate the effect of fiber posts on the fracture resistance of endodontically treated maxillary central incisors with Class III restorations., Material and Methods: Forty extracted human maxillary central incisors were selected and divided into 4 test groups (n=10 each) according to the restoration strategy: control group; endodontically treated teeth without endodontic posts (GHT); endodontically treated teeth with 2 Class III restorations simulating coronal destruction (GCT); endodontically treated teeth with 2 Class III restorations and a carbon fiber post (GCF); and endodontically treated teeth with 2 Class III restorations and a glass-fiber post (GGF). The fiber posts were adhesively cemented with composite resin cement, and the cavities were restored with composite resin. After 3 months of water storage, all specimens were loaded at 45 degrees in a universal testing machine until fracture and evaluated for fracture mode. The data were analyzed using 1-way ANOVA, followed by the Tukey honest significant difference multiple comparisons test (α=.05)., Results: Mean ±SD failure loads ranged from 687.5 ±84.0 N to 943.8 ±93.1 N. One-way ANOVA revealed a statistically significant difference among the groups (P≤.05). The control group (GHT) had significantly higher resistance to fracture than the other groups (P≤.05)., Conclusions: Within the limitations of this in vitro study, placement of a fiber post did not affect the fracture resistance of endodontically treated maxillary central incisors with 2 Class III restorations., (Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.)

Purpose: To evaluate the radiopacity of five post materials using a digital image analysis method., Materials and Methods: Twelve specimens from each post type (two zirconia and three fiber based) of 2 mm in thickness were obtained using a diamond blade mounted on a cutting machine, and digital radiographs were taken along with aluminum step-wedge and dentin discs under standard exposure conditions. The mean gray-values of specimens were measured using a computer graphics program. Data were analyzed using one-way ANOVA followed by Holm-Sidak multicomparison test (p = 0.05)., Results: The highest radiopacity was observed in custom zirconia (5.842 millimeters of equivalent Al [mmAl]), and the lowest value was detected with FRC-Postec (Ivoclar Vivadent) (1.716 mmAl). Significant differences were revealed between the radiopacity values among all groups (p < 0.05), except the Zr post materials (p = 0.56)., Conclusions: All tested post materials had higher radiopacity than dentin. Further studies will be required to clarify optimum radiopacity properties of the post materials to provide a precise clinical observation., (© 2015 by the American College of Prosthodontists.)

Introduction: Endodontic restoration becomes a challenging task for the clinician because of severe loss of coronal tooth structure owing to trauma, caries, restorative, and endodontic procedures. The restoration of these teeth requires the use of a post and core as individual units or as abutment supports for fixed or removable restorations in a predictable long-term manner., Aim: To compare and assess the compressive bond strength of glass, quartz, and carbon fiber posts restored with porcelain-fused-to-metal (PFM) crown., Materials and Methods: A total of 45 upper central incisor teeth having straight root canals, similar anatomically root segments, and fully developed apices were selected. Teeth were divided into three groups of 15 teeth after endodontic treatment. Group I: Teeth inserted with the prefabricated glass fiber post. Group II: Teeth inserted with the quartz fiber post. Group III: Teeth inserted with carbon fiber post. The posts were placed and core was fabricated using composite restoration followed by PFM crown cementation using adhesive resin. Compressive load required to fracture the tooth was measured using a universal loading machine. The difference between the variables was assessed by one-way analysis of variance, followed by Tukey's post hoc test., Results: The compressive strength exhibited by carbon fiber posts was highest with a mean of 668.33 ± 26.397, followed by quartz fiber post (635.80 ± 30.390). Least compressive strength was exhibited by glass fiber post (567.53 ± 26.632). An analysis of variance shows statistically highly significant difference (p < 0.005) among the posts used., Conclusion: This study concluded that the carbon fiber posts had higher compressive strength than other quartz, glass fiber posts., Clinical Significance: Endodontic treatment results in loss of a significant part of the tooth structure. Posts restore these teeth and provide retention.

Purpose: To investigate the fracture resistance of weakened roots restored with prefabricated or CAD/CAM-customized posts and cores as well as the thickness of the cement film and the presence of voids in the cement., Methods: The roots of 40 human premolars were weakened by removing internal dentin with a diamond bur (2.5 mm in the coronal third and 1.5 mm in the apical third) and restored with prefabricated posts (PPs) or customized posts (CPs) with or without a zirconia crown (n= 10). Posts and crowns were cemented with resin cement. Microtomography was used to determine the thickness of the cement film and whether voids were present. After fatigue testing (1 million cycles, 50 N, 5 Hz, 36.5°C), the specimens underwent compression testing with an oblique load (30°, 1 mm/minute) and fracture strengths were recorded (N). Fracture strength and film thickness were analyzed with ANOVA and the Games-Howell test; the variable presence of voids was analyzed with the Mann-Whitney test (α= 5%)., Results: Mean fracture strengths varied between 640.4 and 792.9 N and did not differ significantly between groups. The CP group had a thinner cement film and fewer voids than the PP group. There was a positive, statistically significant correlation (Spearman, R=0.488, P= 0.029) between these variables., Clinical Significance: CAD/CAM-manufactured glass-fiber posts and cores do not affect the fracture strength of flared root canals or cause catastrophic failure of the root when used with zirconia crowns., Competing Interests: The authors declared no conflict of interest.

Background: The purpose of this study was to evaluate the push-out bond strengths of four commercially available adhesive luting systems (two self-adhesive and two etch-and-rinse systems) after mechanical aging., Methods: Forty single-rooted anterior teeth were divided into four groups according to the luting cement system used: Cement-One (Group 1); One-Q-adhesive Bond + Axia Core Dual (Group 2); SmartCem® 2 (Group 3); and XP Bond® + Core-X™ Flow (Group 4). Anatomical Post was cemented in groups 1 and 2, and D.T. Light-Post Illusion was cemented in groups 3 and 4. All samples were subjected to masticatory stress simulation consisting of 300,000 cycles applied with a computer-controlled chewing simulator. Push-out bond strength values (MPa) were calculated at cervical, middle, and apical each level, and the total bond strengths were calculated as the averages of the three levels. Statistical analysis was performed with data analysis software and significance was set at P<0.05., Results: Statistically significant differences in total bond strength were detected between the cements (Group 4: 3.28 MPa, Group 1: 2.77 MPa, Group 2: 2.36 MPa, Group 3: 1.13 MPa; P<0.05). Specifically, Group 1 exhibited a lower bond strength in the apical zone, Group 3 exhibited a higher strength in this zone, and groups 2 and 4 exhibited more homogeneous bonding strengths across the different anatomical zones., Conclusions: After artificial aging, etch-and-rinse luting systems exhibited more homogeneous bond strengths; nevertheless, Cement-One exhibited a total bond strength second only to Core-X Flow.

Statement of Problem: The clinical challenge of adhering cement to intracanal dentin is transmitting light to the most apical parts of root canals to allow more efficient polymerization of the cement., Purpose: The purpose of this in vitro study was to compare the cement-polymerizing ability, microstructure, and radiopacity of a new fiber optic post (iLumi fiber optic Post) with a clinically successful fiber post (DT Light Post)., Material and Methods: Polymerizing ability was compared using a modified depth-of-polymerization protocol. A split aluminum mold with a 12-mm cylindrical hole (diameter=4.7 mm) was filled with light-polymerized resin cement (Variolink Esthetic LC). Each fiber post (n=12) was positioned and light-polymerized on the coronal end for 60 seconds with a light-emitting diode polymerization light. Unpolymerized resin was dissolved with an organic solvent, and the weight and length of the polymerized resin cement were measured. Scanning electron microscopy was used to examine vertical and horizontal cross-sections. The radiopacity values of both the posts and 5 additional reference posts were evaluated using an aluminum step wedge., Results: The weight and length of the polymerized resin cement were significantly greater (P<.05) with the fiber optic post, which scanning electron microscopy showed to have a higher density of parallel fibers. The iLumi post demonstrated greater radiopacity among the tested fiber posts and a titanium alloy post., Conclusions: The iLumi fiber optic posts have a unique structural fiber composition and excellent radiopacity and light-transmitting ability that produce more complete polymerization of the resin cement than the DT Light posts., (Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.)

Aim: To evaluate the percentage volume of voids within cement layers, to determine the push-out bond strength of circular and oval fibre posts luted with different commercial resin cements in oval cross-sectional root canals, and to correlate push-out bond strength values and volume of voids of circular and oval fibre posts., Methodology: Seventy-two mandibular premolars with oval-shaped root canals were selected. The specimens were divided into two main groups according to the post type (oval and circular). Groups were further divided into three subgroups (n = 24) according to resin cement type: Maxcem Elite, Rely-X Unicem and Duo-Link. The volumes of voids within the cements were analysed by micro-computed tomography (micro-CT). The bond strength was then measured using a push-out test with an Instron universal testing machine. The failure modes were evaluated. Statistical analyses were performed using a three-way anova, Tukey's post hoc, Pearson's correlation and chi-square test (P = 0.05)., Results: The push-out bond strength values were significantly affected by root canal region, post type and cement type (P < 0.001). Root canal region, post type and cement type also significantly affected void volume (P < 0.001). There was a significant interaction between post type and cement type (P < 0.001). The most frequent failure type was adhesive failure in all the groups. There was no significant correlation between the push-out bond strength and void volume (P > 0.05)., Conclusions: Void volume did not affect push-out bond strength of oval and circular posts luted in oval canals., (© 2015 International Endodontic Journal. Published by John Wiley & Sons Ltd.)

Introduction: Because there is little information about bond strength of fiber posts cemented with a universal adhesive system (UAS) with different resin cements, the aim of this study was to compare the effect of different bonding strategies in the application of UASs on push-out bond strength of fiber posts to intraradicular dentin., Methods: Seventy-two single-rooted teeth were randomly divided into 6 groups: self-adhesive resin cement (SAC), dual-cure resin cement (DCC), UAS in the etch-and-rinse (E&R) mode and SAC (E&R + SAC), UAS in the self-etch (SE) mode and SAC (SE + SAC), UAS in the E&R mode and DCC (E&R + DCC), and UAS in the SE mode and DCC (SE + DCC). The push-out test was conducted at a crosshead speed of 0.5 mm/min. Data were analyzed with 2-way analysis of variance (P < .05)., Results: Bond strength was significantly influenced by the adhesive strategies (P < .001). However, post space region did not have a significant effect on bond strength (P > .05)., Conclusions: ClearfilSA Luting SAC (Kuraray Noritake Dental Inc, New York, NY) cannot be used alone for fiber post adhesion; it needs an adhesive. Universal adhesive in the SE mode is suggested. When UAS is used for luting fiber posts, the type of cement does not have any effect on bond strength., (Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

The aim of the present study has been to analyze the influence of residual root number and bone density on the loading distribution of restorations combining implant and residual tooth after tooth hemisection using finite element analysis. Based on the image data of two patients, one has one distal root and the other has two distal roots in the mandibular right first molar, eight models were created (four models for each patient): a single crown was placed on the implant and residual tooth in two different bone densities; two separate crowns for the implant and residual tooth in two different bone densities. Vertical force of 100-N was applied on the crowns. The results show that the increase in number of residual roots decreased the magnitude of all biomechanical parameters. Higher values were observed in models with low bone density, especially in one distal root models. The maximum values of strains in spongious bone with the model (one distal root, low spongious bone density, a single crown was placed on the implant and residual tooth) even reached 9000μstrain. From a biomechanical point of view, when two residual roots exist, a single crown placed on the implant and distal half of the molar or two separate crowns for them seem to be an acceptable treatment option, regardless of the bone density. If there is one residual root and the bone density is low, the prosthesis which combines implant with the root might not be used., (Copyright © 2016 Elsevier GmbH. All rights reserved.)

The aim of this study was to evaluate the influence of the residual root and peri implant bone dimensions on the clinical success of the socket shield technique. Thirty-six dental implants were installed in 6 dogs. The clinical crowns of teeth P3, P4 and M1 were beheaded. Afterwards, the roots were worn down 2-3mm in apical direction until they were located at crestal level. Posterior implant beds were prepared in the center of the roots passing by 3mm apically forming 6 groups in accordance to the remaining root thickness. Radiography of the crestal bone level was performed on day 0 and after 12 weeks. Histomorphometric analyses of the specimens were carried out to measure the crestal bone level, the bone to implant contact and the buccal and lingual bone thickness at the implant shoulder portion. Correlations between groups were analyzed through nonparametric Friedman test, statistical significance was set as p<0.05. All 36 implants were osseointegrated, but 3 samples showed a clinical inflammatory reaction and some radicular fragments presented a small resorption process. On the buccal and lingual side, the radicular fragment was attached to the buccal bone plate by a physiologic periodontal ligament. In the areas where there was space between the implant and the fragment, newly formed bone was demonstrated directly on the implant surface. Within the limitations of an animal pilot study, root-T belt technique may be beneficial in preserving and protecting the bundle bone and preservation of soft tissues. If the thickness of the buccal bone is 3mm, and the thickness of the remaining root fragment is 2mm, the socket shield technique is more predictable and the bone contours can be maintained., (Copyright © 2016 Elsevier GmbH. All rights reserved.)

Purpose: The aim of the present study was to clinically evaluate and compare the efficacy and retention of various types of intracanal posts in the restoration of grossly decayed deciduous anterior teeth. The various posts used were polyethylene post, glass post, and composite post., Materials and Methods: A total number of 16 patients with 45 grossly decayed primary anterior teeth were selected. After biomechanical preparation and obturation, patients were randomly divided on the basis of posts to be used into three groups (Group I: Polyethylene post; Group II: Glass post, and Group III: Composite post). Then, space was created in the obturated canal and posts were placed, followed by core build up., Results: After an interval of 12 months, 86.67% of the teeth exhibited complete retention of the post restored with polyethylene post (P > 0.005) and 93.3% of the teeth exhibited complete retention of the post that were restored with glass post (P > 0.005) whereas only 60% of the teeth exhibited complete retention of the post that were restored with composite post (P< 0.005). Only 20% of the teeth exhibited marginal discoloration in both Groups I and III and 13.33% in Group II and this was nonsignificant., Conclusion: Both glass post and polyethylene post proved to be effective. Glass post showed the maximum retention and marginal adaptation followed by polyethylene post. Thus, it appears to be of potential interest for use especially in clinical pediatric dentistry.

Statement of Problem: Direct and indirect techniques are used for intracanal impression and fabrication of cast metal posts. However, whether those techniques affect the accuracy of cast metal posts is unknown., Purpose: The purpose of this randomized clinical trial was to evaluate the accuracy of cast metal posts depending on tooth position and impression technique., Material and Methods: Endodontically treated teeth (anterior or posterior) planned to receive cast metal posts and complete crowns were randomized according to impression technique (direct or indirect). Impressions were made by 2 operators, and time for the impression was recorded. All impressions and cast metal posts were photographed to assess any possible differences between techniques in length of the cast metal post., Results: All cast metal posts were shorter than the impressions. The mean reduction for the metal posts was 2.3% for direct in anterior teeth, 5.7% for direct in posterior teeth, 6.3% for indirect in anterior teeth, and 7.2% for indirect in posterior teeth (all P<.05). Statistically significant differences were found between time of technique and tooth position (P=.031), with the direct technique more time consuming than the indirect technique (P<.001) for both tooth positions. For the indirect technique, the impression times for both tooth groups were similar (P=.459)., Conclusions: Both of the intracanal impression techniques resulted in cast posts that were shorter than the impressed post space. The discrepancy was greatest for the indirect technique. Nevertheless, all posts were considered clinically acceptable and were cemented., (Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.)

Threaded metal pins have been used to create additional retention for large composite resin restorations. However, their dark appearance may compromise esthetic outcome. The use of small fiberglass posts has been advocated as an alternative. This clinical report describes a mini fiberglass post (MFP) used to provide additional retention in a fractured anterior tooth that received a composite resin restoration. The MFP represents a promising option for creating additional retention for large composite resin restorations., (Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.)

Objectives: This randomized clinical trial compared the survival of composite resin restorations and metal-ceramic crowns on endodontically treated teeth that received a glass fiber post using 2 different cementation methods., Methods: Forty-seven patients (age 42.5 ± 11.5) with fifty-seven endodontically treated teeth with extensive coronal damage but always with one intact surface were randomly allocated according to the type of coronal restoration: metal-ceramic crown or composite resin. In case of crown restoration, a core buildup was performed with microhybrid composite resin. The dentin bonding agent and composite resin used were the same for both direct and indirect restorations. Descriptive analysis was performed using FDI clinical criteria and survival of restorations/teeth analyzed using Kaplan-Meier statistics and log-rank tests., Results: 57 restorations (30 composite resin and 27 crowns) were made in 47 patients. The recall rate was 100% and follow up time ranged between 1 and 5 years. One tooth was extracted 11 months post-restoration due to root fracture (composite group). Eight composite restorations and one crown had reparable failures, all due to secondary caries or restoration fracture. The overall annual failure rate (AFR) was 0.92% after 50 months for success of the restorations, with 1.83% for the composite group and 0.26% for the metal-ceramic crown group. The log-rank test showed no difference for survival according to the type of restoration (p=0.344). However, for success rates, metal-ceramic crowns demonstrated better performance (p=0.022)., Conclusions: Indirect restorations provided higher acceptable clinical performance and lower need for re-intervention, but both types of restorations presented good survival rates. (NCT01461239)., Clinical Significance: When endodontically treated teeth with at least one intact surface must be restored, composite resin restorations and metal-ceramic crows are acceptable alternatives to achieve good survival and success rates., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Objectives: The objective was to evaluate whether fiber postsurface conditioning with air abrasion or erbium:yttrium-aluminum-garnet (Er:YAG) laser would influence the bond strength of dual-cure resin cement to the fiber-reinforced (FRC) posts., Materials and Methods: Twenty-one FRC posts were divided into three groups according to surface treatment methods as follows: An untreated control group air abrasion with Al2O3group, and Er:YAG laser treated group with 150 mJ parameter. Fiber posts were then built up to dual-cure resin cement. Eighteen specimens were set and sectioned perpendicularly along the long axis of the post using a saw. Two disks (thickness of 2 mm) were obtained from each specimen (n = 12). Remaining three posts were stored for scanning electron microscopic evaluation. Push out test was performed on the each specimen and the values were recorded as MPa. The data were analyzed using one-way analysis of variance and Tukey post-hoc tests (P < 0.05)., Results: The bond strength values for the groups were as follows: Control (15, 28 MPa), air abrasion group (19, 73 MPa), and Er:YAG group (17, 84 MPa). Air abrasion affected the bond strength significantly (P < 0.05)., Conclusion: Air abrasion attained higher bond strengths when FRC posts were luted to dual-cure resin cement. Additional studies should be designed with different types and parameters of laser devices to understand the effect of these devices on bond strength.

Aim: This manuscript describes a simple reliable technique for restoring severely mutilated primary anterior teeth. A rigid glass ionomer post is created over which zirconia crowns can be fitted to achieve a long-term stable esthetic restoration for primary anterior teeth., Study Design: Children aged 2-5 years with two up to six extensively decayed upper primary incisors were included. Fuji IX was condensed into an intracanal space created to a depth of 3mm, to provide a core which also extended 3mm supragingivally. Crown preparations were completed upon these cores. Zirconia crowns (Nusmile, Houston Texas USA) were fitted and cemented over the prepared cores. All patients were recalled at regular intervals., Results: Twenty-three healthy children with 86 restorations participated in the study. The overall survival of the restorations was 95.3% after 12 months and 80.2% after 24 months. According to Kaplan-Meier survival analysis, the median survival time was not reached while the estimated mean survival time was 22.9 months., Conclusions: This newly described clinical technique is simple and reliable to use for restoration of extensively decayed primary incisors. Use of zirconia crowns retained using this technique offers superior esthetic, durable restorations with remarkable gingival response up to 24 months.

Purpose: Achieving optimal moisture inside the root canal is a challenge during bonding of fiberglass posts. This study evaluated the effect of different moisture patterns on the push-out bond strength (PBS) and nanoleakage (NL) of fiber posts bonded to the root canal of two simplified etch-and-rinse adhesives., Materials and Methods: The roots of 72 human premolars were endodontically prepared and divided into 6 groups according to the combination of the main factors: adhesive (Ambar and Adper Single Bond 2) and moisture (dry, wet, and overwet). The posts were cemented and after 1 week, the roots were cross sectioned into 6 disks. Two disks each were obtained from the cervical, middle, and apical thirds, and the PBS test was carried out (0.5 mm/min; n = 8). The NL was evaluated by scanning electron microscopy after the immersion of specimens in 50% silver nitrate (n = 4). The failure pattern was examined on all debonded specimens. Data were analyzed by three-way repeated measures ANOVA and Tukey's test (5%)., Results: For both adhesives, higher PBS values and lower NL were observed in the wet groups, and lower PBS and higher NL in the dry group. In general, the overwet condition showed intermediate results., Conclusions: The root dentin walls should be left slightly moist before performing fiber post cementation procedures.

Purpose: Pull-out testing was used to determine the tensile load (TL) and tensile strength (TS) of five different fiber post systems bonded to human intracanal dentin., Materials and Methods: 120 caries-free premolars, canines, and maxillary central incisors were divided into 5 different groups for 5 fiber post systems (n = 24): 1. RelyX Fiber Post 3D (RX3D); 2. RelyX Fiber Post (RX); 3. Luxa- Post (LP); 4. FibreKleer 4X Tapered Post (FK); 5. ParaPost Taper Lux (PP). The teeth were prepared and posts inserted. Core buildups were performed with the corresponding product's resin composite. All specimens were stored in water for 24 h at 37°C. TL and TS were tested on half of the specimens (n = 12/group). The remaining samples were thermocycled (10,000 x 5°C/55°C) before testing. TL was directly measured and TS was calculated using the bonding surface. Failure modes were identified using a stereomicroscope. Data were analyzed using twoway ANOVA with the post-hoc Scheffé test, as well as the chi-squared test (p < 0.05)., Results: FK and LP resulted in the lowest mean TL but were not significantly different from those of RX and RX3D. The highest mean TL and TS were observed for PP. Nevertheless, PP fell within the same statistical subset as RX3D and RX. Thermocycling showed no impact on the results. RX3D predominantly showed debonding of the post plus core buildup from the tooth; all other systems mainly demonstrated detachment of the core from the posts., Conclusion: PP, RX, and RX3D together with an adhesive core buildup yielded the highest bond strength to human dentin. Parameters TL and TS showed the same tendencies and statistical evidence.

Background: Single-use dental syringe (SUS) tips eliminate cross-infection risks. Many dental materials are moisture sensitive; therefore bonding could be affected by remaining moisture from SUS tips., Methods: An air-water syringe was calibrated to 50 PSI and the air pressure measured. SUS tips were then attached and pressure re-measured. Seven tips were tested; moisture content and spray pattern were investigated. Ethical approval was granted. Twenty third molar teeth were sectioned, stored in phosphate buffered saline and randomly allocated into groups with a SUS tip. They were mounted in acrylic and polished. Specimens were dried with a tip under standardised conditions, treated using a 3-step etch-prime-bond technique, then had a post bonded perpendicular to the dentine surface. The force to detach them was measured. Data were analysed using one-way analysis of variance (ANOVA) and Chi-squared tests., Results: The difference in output pressure between groups proved significant (p < 0.001). Tensile force at failure was significantly different between groups (p = 0.19)., Conclusions: The pressure output of the syringe and bond strength are influenced by the SUS tip.

Purpose: The aim of this study was to evaluate the microleakage of 4 fiber post-luting systems using the computerized fluid filtration method., Methods: 60 extracted human mandibular permanent premolar teeth were used for the study. The teeth were instrumented with Hedstroem files up to size 60, post spaces were prepared and then Unicore fiber posts were cemented using 4 luting systems. Group1: Duolink, Group 2: Resinomer, Group 3: Fuji Plus, Group 4: Multilink Sprint, Group 5: Positive Control, and Group 6: Negative Control. The samples were stored in distilled water for 2 weeks and then microleakage was evaluated. Data were analyzed with 1 way-ANOVA and Dunett T3 tests (P&lt;.05). Groups 2 and 3 significantly exhibited higher microleakage values than groups 1 and 4 (P&lt;.05)., Results: Resin cements used with total etch-bonding systems demonstrated lower microleakage values than the other cements., Conclusions: Reduction of steps in dentin conditioning of resin luting cements may have a promoting effect on microleakage.

Purpose: To assess the effect of three different drills used for post space preparation on fiber post retention after Reciproc endodontic treatment., Methods: 30 human upper incisors were endodontically treated using Reciproc and warm vertical gutta-percha compaction. Teeth were sealed coronally using Fuji VII, then stored in 0.5% T chloramine solution at 4 degrees C. After 1 week, teeth were randomly assigned to three groups (n = 10) that differed for the drill type used for post space preparation: Group 1: Calibrated drill; Group 2: Largo drill; Group 3: MTwo drill. Illusion posts were luted into the root canals using Gradia Core. After 24 hours, posted roots were transversally cut into 1 mm-thick slices for thin-slice post push-out testing. Two slices per apical, middle, and coronal thirds were obtained, resulting in a total of 6 slices per tooth. Thin-slice push-out test was conducted using a universal testing machine. Post push-out strength was measured in MPa. For the fracture analysis, the specimens were observed using a stereomicroscope at x40 magnification and classified as adhesive [between post-cement (P-C) or dentin-cement (D-C) interface], cohesive (within the post or adhesive cement) and mixed (adhesive and cohesive fractures occurred simultaneously). Between-group differences in post retentive strength were statistically analyzed (Kruskal-Wallis ANOVA, Dunn's Multiple Range test, P > 0.05). Differences in push-out strength among root levels within each group (one-way ANOVA or Kruskal-Wallis ANOVA, depending on the normality of data distribution, P> 0.05) and in failure mode distribution were also statistically evaluated (Fisher's Exact Test, P > 0.05)., Results: For each group the mean of MPa values was: (1) 10.41 ± 3.56, (2) 10.98 ± 3.96, and (3) 12.11 ± 1.65. Failure mode was distributed as follows: Adhesive: (1) P-C - 23.3%, D-C - 21.7%; (2) P-C - 20%, D-C - 10%; (3) PrC - 46.7%, D-C - 13.3%; Cohesive: (1) 0.0%, (2) 3.3%; (3) 0.0%; Mixed: (1) 55.0%; (2) 66.7%; (3) 40.0%. The statistical analysis revealed the existence of significant between-group differences (P= 0.002). Group 3 measured significantly higher push-out strengths than Groups 1 and 2, which were comparable. Statistically significant between-group differences emerged also in failure mode distribution (P= 0.004). In Group 3 post-cement adhesive failures were significantly more frequent and mixed failures were significantly less frequent than in Group 2. No statistically significant differences emerged among the different root levels of the tested groups (P > 0.05).

Aim: To review the available evidence for the causes of failure of fibre posts., Materials and Method: A search of MEDLINE was conducted to retrieve available data on fibre posts used for restoration of endodontically treated teeth since 1980. The Cochrane Library was also separately searched for systematic reviews. Additionally, references of the retrieved articles were also hand searched for further relevant papers. All the selected papers were then critically appraised subject to meeting inclusion criteria., Results: Nineteen prospective clinical trials were included after critical appraisal of the papers. Causes of failure of fibre posts were identified as follows: adhesive failure, root fracture, post fracture, endodontic failure, secondary caries and periodontal complications. Risk factors for each of the failures were investigated and evidence-based recommendations for minimising these complications are discussed., Conclusion: Although laboratory studies showed favourable mechanical and physical properties of fibre posts, clinically, there has been a wide range of failures mechanisms are reported in the literature. Adhesive failure was reported in 16 of the 19 trials, making it the most frequent cause of failure. The available evidence does not indicate a difference in short-term survival probability between metal or fibre posts. A number of risk factors, which affect the longevity of fibre posts, were identified and discussed. Since there is considerable heterogeneity in study designs and reported survival rates of included studies, longer-term well-designed standardised clinical trails are required.

Objective: Intra-canal post systems are commonly used to restore root-filled teeth. Bond strengths of the posts can be affected by various surface treatments of the post or the dentin. The aim of this study was to evaluate the effects of dentin surface treatments including erbium-chromium; yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser irradiation with different intensities on the push-out bond strength of the glass fiber posts to root dentin., Materials and Methods: Forty single-rooted human maxillary incisors were filled and post spaces were prepared. After these procedures, the specimens were divided randomly into four groups according to the dentin surface treatments, as follows: (i) untreated surface (control), (ii) 1W Er,Cr:YSGG laser application, (iii) 2W Er,Cr:YSGG laser application and (iv) 3W Er,Cr:YSGG laser application. Then the posts were cemented into the root canals using dual-cured resin cement. Bonded specimens were cut into 1-mm-thick slices and push-out tests were performed using a universal testing device. All specimens were loaded until fracture and the failure modes were evaluated with a stereomicroscope at 32× magnification. Representative specimens were analyzed by scanning electron microscopy. Data were analyzed using a one-way ANOVA, Tukey and Wilcoxon tests., Results: The bond strength values ranged from 3.22-4.68 MPa. There were no statistically significant differences among the groups, regardless of the different levels. The coronal and middle levels of the post space had significantly higher bond strength values compared with the apical level (p < 0.05)., Conclusion: Er,Cr:YSGG laser irradiation with different intensities did not increase the bond strength of the fiber posts to the root canal dentin walls.

Aim: The aim of this study was to evaluate the effect of chlorhexidine and ethanol application on the push-out bond strength and bond durability of fiber posts cemented with an etch-and-rinse adhesive system/resin cement to intraradicular dentin., Materials and Methods: Fifty-four bovine roots were shaped for the cementation of a fiberglass post and received the application of 37% phosphoric acid. They were then randomly divided into three groups, according to the type of dentin treatment (n = 18) performed: no treatment (control group), 100% ethanol, or 2% chlorhexidine. Next, the adhesive system (Adper Scotch Bond Multipurpose Plus, 3M ESPE) was applied to the dentin, according to the manufacturer's instructions. Glass fiber posts were cemented with dual resin cement (Rely X ARC, 3M ESPE). After 48 hours, the specimens were serially sectioned for push-out test analysis, providing two slices from each root third (cervical, medium and apical), one of which was tested immediately and the other stored in distilled water for 180 days. The data were analyzed with three-way analysis of variance (ANOVA) for repeated measures and Tukey's test at a 5% significance level., Results: Intraradicular treatment with chlorhexidine yielded the highest bond strength means, followed by ethanol treatment. The control group presented the lowest bond strength means. Water storage exerted no effect on bond strength values., Conclusion: Both chlorhexidine and ethanol improved push-out bond strength to intraradicular dentin, with the former providing the best results, regardless of the storage time., Clinical Significance: The application of 2% chlorhexidine or 100% ethanol may be an important step that can be taken to enhance bond strength of fiber posts to intraradicular dentin, when dual resin cements are used.

This study evaluated the influence of relining fiber posts on the bond strength (BS) of resin cements in the root canal. Forty bovine teeth were divided in four groups (n = 10): G1 (ARC)-fiber post cemented with resin cement RelyX ARC; G2 (ARC+Z350)-relined fiber post cemented with RelyX ARC; G3 (U200)-fiber post cemented with self-adhesive cement RelyX U200; G4 (U200+Z350)-relined fiber post cemented with RelyX U200. The roots were sectioned in six 1.2-mm slices and the push-out test was performed. Data were analyzed by three-way analysis of variance (ANOVA), and Tukey's test (a = 0.05). For the conventional resin cement, there was no significant difference between groups G1-ARC (15.5 ± 3.8) and G2-ARC+Z350 (16.1 ± 4.5). For the self-adhesive cement, the results revealed higher BS values for relined posts G4-U200 + Z350 (19.9 ± 7.9) as compared to non-relined posts G3-U200 (14.4 ± 4.5). For both cements, in groups of relined posts, the apical and the cervical thirds presented similar BS. Relining enhances the performance of the self-adhesive resin cement, and the interaction between relining and root third influences the BS to the conventional resin cement.

Objective: The aim of this study was to investigate the effects of photon-initiated photoacoustic streaming (PIPS) with various irrigating solutions on the bond strength of a self-adhesive resin cement to root dentin., Materials and Methods: Seventy-two mandibular premolar roots were divided into six groups after post space preparation and treated with a needle irrigation with distilled water and NaOCl, ultrasonic irrigation with NaOCl, PIPS with NaOCl, PIPS with EDTA and PIPS with distilled water at 0.3 W, 15 Hz and 20 mJ per pulse for 60 s. Fiber posts were cemented with a newly marketed, self-adhesive resin cement. The data obtained from the push-out tests were analyzed using analysis of variance (ANOVA) and LSD post-hoc tests (p = 0.05)., Results: PIPS with distilled water resulted in higher push-out values than those of needle (with both distilled water and NaOCl) and ultrasonic irrigation (p < 0.05)., Conclusions: The use of PIPS may provide higher bond strength of self-adhesive resin cement to root dentin than needle and ultrasonic irrigation techniques.

Statement of Problem: How the location of a ferrule affects the fracture resistance of endodontically treated mandibular premolars is unclear., Purpose: The purpose of this in vitro study was to compare the effect of ferrule location on the fracture resistance of endodontically treated mandibular premolars., Material and Methods: Seventy-two extracted human mandibular premolars were selected and divided into 6 test groups (n = 12) according to ferrule location: control group, GHT; endodontically treated teeth without endodontic posts and crowns, GCF; teeth with a 2 mm circumferential ferrule, GBF; teeth with a 2 mm buccal ferrule; GLF, teeth with a 2 mm lingual ferrule; GBLF, teeth with a 2 mm buccal and lingual ferrule; and teeth without ferrule, GWF. After glass fiber posts were cemented with a self-adhesive resin cement and foundation restorations were placed, NiCr crowns were luted to each prepared tooth. All specimens were quasistatically loaded at 30 degrees in a universal testing machine until fractured. Data were then analyzed with 1-way ANOVA, followed by multiple comparisons using the Tukey honestly significant difference test (α=.05)., Results: Mean ± SD failure loads for groups ranged from 791.1 ± 177.5 N to 1086.1 ± 181.1 N. One-way ANOVA revealed a statistically significant difference between the groups (P ≤ .05). However, no statistically significant differences were observed among groups (P > .05), except between GHT (control group) and groups GBLF and GWF (P = .025, P = .022)., Conclusions: Within the limitations of this study, the location of the ferrule had no significant effect on the fracture resistance of endodontically treated mandibular premolars., (Copyright © 2015 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.)

Objective: To evaluate the effect of instrumentation techniques, irrigant solutions and specimen aging on fiberglass posts bond strength to intraradicular dentine., Materials and Methods: A total of 120 bovine teeth were prepared and randomized into control and experimental groups resulting from three study factors (instrumentation techniques, irrigant solutions, specimen aging). Posts were cemented with RelyX U100. Samples were submitted to push-out test and failure mode was evaluated under a confocal microscope., Results: In specimens submitted to water artificial aging, nickel-titanium rotary instruments group presented higher bond strength values in apical third irrigated with NaOCl or chlorhexi-dine. Irrigation with NaOCl resulted in higher bond strength than ozonated water. Artificial aging resulted in significant bond strength increase. Adhesive cement-dentin failure was prevalent in all the groups., Conclusion: Root canal preparation with NiTi instruments associated with NaOCl irrigation and ethylenediaminetetra acetic acid (EDTA) increased bond strength of fiberglass posts cemented with self-adhesive resin cement to intraradicular dentine. Water artificial aging significantly increased post-Clinical significance: The understanding of factors that may influence the optimal bond between post-cement and cement-dentin are essential to the success of endodontically treated tooth restoration.

Vertical root fractures are often observed in teeth with endodontic treatment and post space preparation. Frequently, because such teeth have flared root canals with thin dentin walls, conventional treatments are disadvantageous in terms of adhesiveness, sealability and risk of refracture. Here we devised an intentional replantation method that uses internal resin coping, with a reinforcing effect on thin root canal dentin. In two patients treated with this method, satisfactory conditions have been maintained. This report suggests that an intentional replantation method in which an internal resin coping is employed may be a useful therapy for fractured teeth with flared root canals.

Purpose: To assess the fracture strength of cavity preparations, directly restored with resin composite, with and without the presence of fiberglass posts with different diameters., Methods: 84 extracted third molars were embedded in acrylic resin and divided into six groups (n = 14 per group): healthy (H); cavity preparation (P); cavity preparation + endodontic treatment (PE); PE + resin composite (R); PE + R + 2 horizontally transfixed fiberglass posts 1.1 mm in diameter (PERP1); PE + R + 2 fiberglass posts 1.5 mm in diameter (PERP2). The MOD cavity preparations were standardized with their width corresponding to 2/3 of the buccolingual distance and occlusogingival depth of 4 mm, with 2 mm remaining above the cemento-enamel junction. Endodontic treatments were performed in the PE, R, PERP1 and PERP2 groups. The buccal surface received two demarcations to create orifices for placement of the PERP1 and PERP2 posts. Once the fiberglass posts were placed, the teeth were restored with resin composite. In group R, only resin composite was used. After 24 hours, the teeth were subjected to the fracture toughness test on a universal testing machine. A 10 KN load cell and crosshead speed of 1 mm/minute was used until fracture occurred. After testing, the teeth were inspected for the type of fracture classified as: pulpal floor fracture (AP) or cuspal fracture (CP)., Results: The data were subjected to ANOVA and Tukey's test (P < 0.05%), demonstrating a statistical difference between groups: H 3830NA; P 778ND; PE 572.93ND; R 1782NC; PERP1 2988NB; PERP2 3100NAB. The fracture pattern was similar between the tested groups, showing 50% of fracture for cusps and pulpal floor.

Restoration of an anterior root-filled tooth with little remaining coronal tooth-tissue can utilise a post to retain a core, enabling definitive restoration. Post material was, until recently, primarily metal--be it cast or prefabricated. Currently, fibre-posts are promoted as being advantageous due to a favourable failure mechanism which may protect the root from fracture. This Case Report demonstrates failure of the structural integrity of a fibre-post in a maxillary lateral incisor, with a proposed explanation. Retreatment employed a diamond-coated ultrasonic tip for removal of the residual fibre-post and restoration with a cast-post and metal ceramic crown.