Bond Strength Of Glass Fiber Research Articles

Microhardness and Pushout Bond Strength of Glass Fiber Post-to-Canal Dentin Irrigated with Boric Acid, Nd: YAP, AgNPs, and Curcumin Activated with Microbubble Emulsion. A SEM, EDX Analysis

This study aimed to assess the microhardness (MH) and push-out bond strength (PBS) of fiber post-to-canal dentin when boric acid (BA), Nd: YAP, silver nanoparticles (AgNPs), and microbubble emulsion (MBE) with curcumin were used as irrigants. Canal therapy was performed and the post space was prepared. Prior to glass fiber post (GFP) insertion, the post space was irrigated using 2.5% NaOCl+17% EDTA, 10% BA+EDTA, Nd: YAP laser+EDTA, AgNP+EDTA, and MBE (curcumin)+EDTA. Following disinfection, microhardness was evaluated. GFP was then inserted and PBS was assessed at the coronal, middle, and apical levels, along with the examination of debonded surfaces via stereomicroscope. The data were analyzed using ANOVA and a Post Hoc Tukey HSD test. The results showed that MH was highest in the group treated with AgNP+EDTA and lowest in the group treated with 10% BA+EDTA. Within the cervical region, the Nd: YAP laser+EDTA group showed the lowest PBS, while the highest PBS was observed in the group treated with MBE (curcumin)+EDTA. In the middle region, the GFP bonded to canal dentin disinfected with 2.5% NaOCl+EDTA was comparable to that treated with Nd: YAP laser+EDTA. In the apical region, the PBS of GFP was highest in the canal disinfected with MBE (curcumin)+EDTA. The study concluded that silver nanoparticles+EDTA and curcumin photosensitizer via microbubble emulsion+EDTA have the potential to be used as alternatives to conventional methods for improving the adhesion of glass fiber post-to-canal dentin, along with enhancing microhardness.

Aspects of glass and hybridization protocols for bonding of fiber posts to root dentine.

This study evaluated bond strength of glass fiber posts to root dentin using push-out (PO) and diametral compression (DC), testing glycolic acid as a conditioner and varying dentin moisture. An additional aim was to test whether DC can be an alternative test to PO for bond strength assessment. Eighty bovine teeth were divided into eight groups (n=10) defined by the use of either 37% glycolic acid or 37% phosphoric acid (PA) on moist or wet dentin before bonding with either Adapter SingleBond/RelyX ARC or One Step Plus/Duo-Link Bisco. Each tooth provided discs with an internal diameter of 2mm, external diameter of 5mm, and height of 2mm, which underwent PO and DC. Finite element analysis (FEA) was carried out on 3D models. When analyzing PO results through linear regression, the highest values of bond strength were observed using glycolic acid on wet dentin in the cervical and middle thirds of the teeth. Analyzing DC results, the only statistical influence on values was the dental thirds. The scatterplot of the DC results and the PO bond strength values indicated no relationship between the results of the two tests (r=0.03; p=0.64). PO test detected more sensitive changes in bond strength values than DC.

Final Irrigant Temoporfin, Femtosecond Laser, and Chitosan Nanoparticles on Extrusion Bond Strength of Glass Fiber Post, Microhardness, and Modulus of Elasticity of Canal Dentin

Final root canal disinfectants Temoporfin, Femtosecond (FS) laser, and Chitosan nanoparticles (NPs) on marten hardness (MH), modulus of elasticity (EIT), and push-out bond strength (PBS) of glass fiber reinforced post (GFRP) to the root dentin. Sixty caries-free single-rooted human premolars were decoronated and a root canal was performed followed by post space. The specimens were then arbitrarily allocated into groups according to the final disinfectant used. Group 1: 17% EDTA, Group 2: Temoporfin, Group 3: FS laser and Group 4: Chitosan NPs. Evaluation of mechanical properties (MH and EIT) was performed on five samples from each group. Ten samples from each group were bonded with GFRP and sectioned. A universal testing machine and stereomicroscope were used to analyze the PBS and failure mode. Means and standard deviations (SD) of MH, EiT, and PBS were assessed using ANOVA and post hoc Tukey. The highest values of MH and EiT were revealed by 5.25% NaOCl+Chitosan NP samples. The lowest scores of MH and EiT were presented by samples irrigated with 5.25% NaOCl+17% EDTA. The coronal section of samples treated with 5.25% NaOCl+Chitosan NPs showed the highest EBS. Chitosan NPs and FS laser have proved to be valuable alternatives to EDTA as both improved PBS without deteriorating the MH and EiT.

Experimental Study of Glass Fiber Reinforced Concrete Incorporating Micro Silica

The most common building material utilized worldwide is concrete. Concrete with higher compressive strength is becoming more and more in demand as the trend toward using it more widely for high rise buildings. Experimental study of glass fiber (GF) reinforced concrete incorporating micro silica was investigated in this study. The concrete is prepared by using M40 mix. GF with 12 mm length with aspect ratio of 857 is used. Four volume fractions of 0%, 0.4%, 0.8% and 1.2% by weight of cement and micro silica with 5% by weight of cement are used. The fiber is distributed randomly in all directions. The mixes were cast and tested for workability, compressive strength, flexural strength, water permeability test, drop weight Impact test, bond strength test and residual compressive strength at elevated temperature. Micro structural study is done with SEM analysis. Workability of glass fiber reinforced concrete decreased with increase in GF. Compressive strength show 12% increment whereas Flexure strength is increases 35% compare to normal concrete. Different percentages of glass fibres and micro silica have lower water penetration depths. With regard to the fire resistance test the compressive strength at elevated temperature decreases significantly. Impact resistance and bond strength of glass fiber reinforced concrete with micro silica increases with increase in fiber content. Hence, it's suggested to use glass fiber in the concrete according to use of concrete.

Which irrigating provides a better bond strength in glass fiber posts: Chlorhexidine or Sodium Hypochlorite? A systematic review with meta-analysis.

The aim of this systematic review and meta-analysis was to evaluate the influence of the use of chlorhexidine on endodontic instrumentation on the bond strength of glass fiber posts with resin cements. The guiding question of the study was: "Is the bond strength of glass fiber posts greater when using chlorhexidine as an irrigator in endodontic treatment instead of sodium hypochlorite?". This study was conducted according to Guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA). In vitro studies were included that have compared chlorhexidine and sodium hypochlorite as an endodontic irrigator in the chemical-mechanical preparation. Eight studies were included in the qualitative analysis and seven in the meta-analysis. Both the analysis by subgroups and the total analysis, using a random effect model, showed no statistically significant differences between the groups (p> 0.05), either in the specific analysis for cervical root third (p = 0.30; 95% CI = -2.11, 6.91) or medium (p = 0.05; 95% CI = -0.03, 4.56), or nonspecific regarding the third to the root third (p = 0.48; 95% CI = -4.00, 1.86). There are no statistically significant differences in the bond strength of glass fiber posts and resin cements in teeth endodontically treated under irrigation by both chlorhexidine and sodium hypochlorite. Key words:Chlorhexidine, sodium hypochlorite, bond strength, glass fiber post.

Influence of photodynamic therapy, different final irrigants, and ultrasonic activation on the bond strength of glass fiber posts to root dentin

ObjectiveTo evaluate the influence of photodynamic therapy (PDT), different final irrigants, and ultrasonic activation (US) on the bond strength of glass fiber posts (GFP) to root dentin. MethodsOne hundred twenty bovine roots were divided into 12 groups according to PDT application, the type of final endodontic irrigant, and US. The samples were divided into 12 groups (n = 10): G1-DW(distilled water); G2-DW+US; G3–17% EDTA; G4–17% EDTA+US; G5–17% GA (glycolic acid); G6–17% GA+US; G7-PDT+DW; G8-PDT+DW+US; G9-PDT+17% EDTA; G10-PDT+17% EDTA+US; G11-PDT+17% GA; G12-PDT+17% GA+US. After cementing the glass fiber posts with resin cement, roots were sectioned into 2-mm-thick slices. One slice from the cervical third and another from the middle third were used for the push out test (PO), and the other two for the diametral compression test (DC). Thus, 10 samples were obtained per third for each mechanical test (n = 10). Kruskal-Wallis and Student-Newman-Keuls tests were used to analyze PO and DC data, and Pearson's correlation test was used to verify the relationship between the variables. Failure patterns were analyzed with chi-square test. ResultsSignificant differences were found in the PO test among the experimental groups (p < 0.001; power=1.00). PDT improved bond strength when using EDTA. PDT and US increased bond strength when using GA. Favorable failure patterns occurred more frequently in Group GA+US. There was no correlation between data obtained with PO and DC tests (r = 0.112; p = 0.729). ConclusionPDT provided the highest bond strength values of GFP to root dentin when associated with GA and US or when associated only with EDTA.

The impact of provisional intraradicular retainers cementation with temporary methacrylate-based resin in the bond strength of glass fiber posts to root dentin

Chemical composition of temporary cements interferes in the bond strength and quality of the bond interface of glass fiber posts to root dentin. The aim of the present study was to evaluate the influence of different temporary cements on the bond strength of fiberglass posts and resin cement. Thirty-two maxillary central incisor roots were standardized at 15 mm length. The root canals were prepared with Reciproc R50 and filled with a R50 single cone and AH Plus. Ten mm of filling material was removed with a heated Schilder condenser, leaving 5 mm of apical filling material. The roots were randomly distributed into 4 groups (n = 8). In the control group, the root canal was prepared with a standard drill according to the post diameter (DC #1, FGM, Joinville, Brazil), irrigated with 5 mL of distilled water and immediately received the fiberglass post cemented with self-adhesive resin cement. For the other groups, cores were made with temporary intraradicular retainers cemented with different temporary cements: methacrylate-based resin (Bifix Temp - Voco), calcium hydroxide-based (Provicol - Voco) and zinc oxide-based – eugenol-free (Relyx Temp NE - 3M). After 7 days, mechanical removal of the temporary retainers, preparation, irrigation of the root canal and cementation of the fiberglass post were performed, following the same protocol that had been performed in the control group. The roots were sectioned to obtain 3 slices per root third. The most cervical section of each third was used for the push-out test and failure pattern analysis, while the most apical section was subjected to analysis of the adhesive interface by scanning electron microscopy (SEM). The BS data were compared between groups using the two-way ANOVA and Tukey post-test. The failure pattern results were expressed in percentage and compared between groups using the chi-square test and the material adaptation data at the bond interface were evaluated using the Kruskal-Wallis and Dwass-Steel-Critchlow-Fligner tests. The results showed higher BS in the cervical third, with a higher value in the control group (10.8 ± 0.94) and Bifix Temp group (9.78 ± 0.71), with no statistically significant difference between these groups (P > .05). The middle and apical thirds showed no statistically significant difference (P > .05). As regards the type of failure, a higher percentage of mixed adhesive failures was observed for all groups. Analysis of the adhesive interface by SEM showed that the temporary cement Bifix Temp showed greater adaptation at the bond interface. It was concluded that the methacrylate-based resin temporary cement showed the highest bond strength values and best adaptation to root dentin than the zinc oxide-based and calcium hydroxide-based temporary cements.

Effect of Posts Surface Treatments on the Pull-out Bond Strength of Glass Fiber Post to Root Dentin “A Comparative In-Vitro Study”

Effect of Posts Surface Treatments on the Pull-out Bond Strength of Glass Fiber Post to Root Dentin “A Comparative In-Vitro Study”

The Effect of Application of Sonic Vibration on the Bond Strength of Glass Fiber Post to Root Dentin using Duo-link and Theracem cements: An In Vitro Study

Background: This study investigated the impact of sonic vibration on the root dentin-glass fiber post bond strength using two resin cements. Materials and methods: Forty single-canal teeth were randomly divided into four groups (n = 10): Theracem self-adhesive using sonic vibration, Duo-link cement using sonic vibration and abrasion, Theracem self-adhesive, and Duo-link cement. Data were analyzed by one-way analysis of variance, Tukey test, and independent t test (α = 0.05). Results: In the coronal region, the bond strength was not significantly different among the four groups (P = 0.331). In the apical region, the bond strength was significantly higher in the Duo-link cement using sonic vibration than in the Theracem cement using sonic vibration (P = 0.010) and Theracem cement using the conventional method (P = 0.007). Conclusion: Sonic vibration has positively affects the push-out bond strength of glass fiber post to root dentin using Duo-link cement.

Comparsion of two different dentin pretreatment protocols on bond strength of glass fiber post using self-etch adhesive

Aim and objectives Aim: Is to evaluate the two different natural crosslinking agents citric acid and grape seed extract. Objective: To know the difference between the two agents on bond strength of fiber post on to root dentin using self-etch adhesive. Materials and Methods 1. 30 Single rooted maxillary anterior teeth with similar root segments and fully developed apices were selected. 2. Root canal treatment is performed and post space preparation is done using #2 peeso reamers and irrigated with 2.5% NaOCl and 17% of EDTA and dried with paper points and then divided in to 3 groups according to pretreatment used. Group 1: No pretreatment, only conventional self-etching & bonding. (Control Group). Group 2: Pretreatment with 10% citric acid for 5 Minutes. Group 3: Pretreatment with 6.25% Grape seed extract for 5 Minutes. 3. The post space treated with self-etch adhesive and fiber post is bonded using flowable composite 4. Bond strength evaluation is done by transversely sectioning the roots of each group of 1.0 MM, thickness and 3 sections were obtained and embedded in acrylic resin block. Micro push-out bond strength was measured using universal testing machine and SEM analysis is done to classify the facture pattern.

Efficiency of Erbium-Doped Yttrium Aluminum Garnet Laser in Debonding Cemented Glass Fiber Posts: an in vitro Study.

Statement of the Problem: The efficacy of erbium-doped yttrium aluminum garnet (Er; YAG) laser on the debonding properties of certain post materials has remained largely unexplored. Purpose: This study aimed to investigate the effect of Er; YAG laser irradiation on debonding of cemented glass fiber posts in root canal treated teeth.Materials and Method: In this in vitro study, forty root canal treated mandibular premolar teeth were used in this study. Glass fiber posts were bonded using Panavia F 2.0 cement in the root canal space, and samples were divided into two groups. In the test group, samples were exposed to laser radiation of 7W, 350mJ, frequency of 20Hz and discontinued washing spray. In the control group, samples were left untouched. In each group, samples were sectioned into 1.5mm thick slices from the coronal, middle, and apical thirds of the root (N=120). Tensile bond strengths were evaluated using the push-out test and the failure patterns were evaluated using scanning electron microscopy (SEM). To compare the laser and non-laser groups at each location, independent sample t test was applied, and to compare bond strength between the locations in each group, one-way ANOVA and Tukey’s HSD post hoc was applied.Results: A significant difference in tensile strength was observed between the laser-irradiated group and control group; tensile bond strength was much higher in the control group (p<0.001). The highest frequency of fractures was observed at the cement-dentin interface. Given the used parameters, complete debonding was not achieved in the laser-irradiated group.Conclusion: Laser radiation reduced the bond strength of glass fiber posts to resin cement without complete debonding.

An Experimental Study on Effect of Concrete Type on Bond Strength of GFRP Bars

One of the common methods to create bond strength in reinforced concrete is providing development length. The bond strength of glass fiber reinforced polymer (GFRP) bar is inherently poor due to its shape, as well as its inadequate mechanical interlocking with concrete. Therefore, providing sufficient development length in this bar is different and more conservative in comparison with steel bars. In this study, three types of concrete are selected, namely normal-weight concrete (NWC), light-weight concrete (LWC), and light-weight fiber reinforced concrete (LFRC). In order to investigate the adequate development length required for GFRP bars and its relation with the concrete type and compressive strength, for Each type of concrete, two different mix designs which have various compressive strengths are considered. 18 cube specimens are fabricated and the direct pull-out test is performed. The results indicate that, in all types of concrete, as the compressive strength increases, the bond strength between concrete and rebar augments. In addition, assessing the bond strength of different types of concrete demonstrates that the use of LWC, due to its inherent weakness of aggregates interlocking, causes pre-mature cracks and loss of the bond strength compared to NWC. Furthermore, LFRC mixtures containing 0.3% and 0.5% macro-synthetic fiber volume fraction reveal that the presence of fibers can be effective in controlling cracks and increases the bond strength between GFRP bars and concrete. As a result, with the increase of the bond strength between the GFRP bar and the concrete, the ultimate capacity of the concrete cross-section augments.

Light transmission and bond strength of glass fiber posts submitted to different surface treatments

Statement of problemLight transmitted deep into the root canal is an important parameter to increase bonding of the cement to the post and dentin. Glass fiber posts seem to be an option to increase transmitted light, but literature on the light transmittance profile and power transmission to deep canal regions is lacking. PurposeThe purpose of this in vitro study was to evaluate light delivered by 2 types of fiberglass posts submitted to different surface treatments and to evaluate the bond strength. Material and methodsWhiteposts and Superposts were allocated to 4 groups: no surface treatment, surface treatment with 24% hydrogen peroxide, surface treatment with silane, and surface treatment with 24% hydrogen peroxide plus silane. The total light transmitted by the posts was measured by using an integrating sphere to collect the diffuse light. The light profile that was laterally delivered to the post was measured with a power detector equipped with an optical fiber probe. The bond strength was measured with the push-out test. Scanning electron microscopy was used to evaluate the surface treatments. The light transmission data were analyzed by using a generalized linear model and the Bonferroni test and the bond strength values were evaluated by using ANOVA and the Tukey test (α=.05). ResultsThe cervical third presented the highest transmission (74.1% for Whiteposts and 74.6% for Superposts), followed by the middle (20.9% for Whiteposts and 20.4% for Superposts) and apical (5.0% for both Whiteposts and Superposts) thirds. Superposts led to higher bond strength than Whiteposts (9.73 ±5.89 and 8.48 ±4.99 MPa, respectively). Surface treatment with silane and hydrogen peroxide plus silane afforded similar bond strength (11.4 ±6.4 and 10.7 ±5.6 MPa, respectively), which was higher as compared with the bond strength obtained after surface treatment with hydrogen peroxide. For both post types, the bond strength decreased from the cervical (12.2 ±6.0 MPa) to the middle (9.7 ±5.0 MPa) and apical (6.5 ±3.6 MPa) thirds. ConclusionsLight transmission and bond strength decreased from the cervical to the apical third. Surface treatment impacted bond strength; light transmission through Whiteposts was slightly higher than light transmission through Superposts.

Push Out Bond Strength of a Glass Fibre Post to Root Dentine Pretreated with Proanthocyanidin and Phytosphingosine - An In Vitro Study.

Objective:To evaluate the push out bond strength of a glass fibre post to root dentine pretreated with 6.5% proanthocyanidin (PAC) and 0.02% phytosphingosine (PHS).Methods:Thirty-three freshly extracted single rooted human teeth were decoronated to a length of 14 mm. Root canals were prepared using rotary NiTi files and obturated with gutta percha and resin sealer. Post space was prepared using peeso reamers, retaining 5 mm of apical gutta percha. Following smear layer removal and acid etching of the post space, samples were randomly assigned to 3 groups based on the dentine pretreatment, namely the control (no pretreatment) group, 6.5% PAC group, and 0.02% PHS group. A glass fibre post was luted using a dual cure adhesive and luting cement. 1 mm thick root slices were sectioned from coronal, middle and apical levels of the post and their push out bond strength was evaluated using a universal testing machine. Data was analysed with one-way ANOVA and Games-Howell post hoc test (P<0.05).Results:At all levels, PHS showed higher push out bond strength than PAC and control groups, with a significant difference between the experimental groups at the middle and apical thirds (P<0.05). The push out bond strength of PAC group was significantly higher than the control group in the coronal and apical thirds (P<0.05).Conclusion:Both PAC and PHS improved the push out bond strength of a glass fibre post to dentine.

Effect of Endodontic Retreatment Protocols on Bond Strength of Fiberglass Post to Root Canal Dentine: An In-vitro Study

Effect of Endodontic Retreatment Protocols on Bond Strength of Fiberglass Post to Root Canal Dentine: An In-vitro Study

The mussel-inspired polydopamine surface treatment influences bond strength of glass fiber posts to radicular dentin

The aim of this study was to compare the efficacy of silane and a novel bioinspired polydopamine functionalization on the adhesion strength of glass fiber posts cemented to root dentin. Sixty-four surface treated posts [polydopamine (group 1 = 32) or silane (group 2 = 32)] were cemented in root canals of 64 extracted and decoronated mandibular premolars by using 3 commercial brands of self-adhesive resin cements (subgroups A, B and C) or a total-etch resin cement (subgroup D). The samples were subjected to push-out bond strength testing at 24 h and at 6 months after storage in water. Each sample was subdivided into six slices (three slices of the coronal and three slices of the apical) to determine the push-out bond strength in the coronal and apical third. The mean bonding strength value of the 3 slices both for the coronal and apical third was calculated as megapascals (MPa) and the data were statistically analyzed using post hoc Tukey HSD and Student t tests using four-way ANOVA (P = 0.05). Failure modes were investigated using scanning electron microscopy (SEM). The number of adhesive failures at the dentin-cement interface dropped when polydopamine was used (12–33%). Failure between the post and cement interface also dropped (4–13%) in all the resin cement groups, except the Subgroup C (17%). Polydopamine treatment significantly increased the adhesion strength for all cements compared to silanization at 24 h (P < 0.05), however at 6 months, only for the self-adhesive cements (P < 0.05). Polydopamine surface treatment improves the short-term bond strength of fiber-posts cemented to root canal dentin. The positive effect of polydopamine on long-term bond strength did not appear to be significant for the total-etch resin cement.

Does acid etching prior to applying universal adhesives affect the bond strength of glass fiber post to root dentin?

The aim of this study was to evaluate if acid etching prior to application of different universal adhesives influences the bond strength of the glass fiber post to root dentin. One hundred and twenty (120) bovine-tooth roots were prepared to receive glass fiber posts #3 (White Post, FGM) and then divided into 12 groups (n = 10) according to two factors: the adhesive system (Single Bond Universal, Ambar Universal, Prime & Bond Universal, Gluma Bond Universal, YBond Universal or Ambar Universal APS); and acid etching prior to application of the adhesive (presence or absence). After cementation, the specimens were stored in a humid environment at 37 °C for 24 h. Each sample was sectioned into 5 slices with 1.5 ± 0.2 mm thickness and subjected to a pushout test with an increasing load of 1 mm/min in a universal testing machine until failure and the data were analyzed using two-way ANOVA and post-hoc Tukey's tests. There was no statistical difference in the bond strength values for the acid etching factor. There were only differences for the adhesive system factor. Higher bond strength values were found for the Universal Single Bond adhesive (3 M) regardless of acid etching or not, and for Gluma Bond Universal adhesive without acid etching. It was possible to conclude that acid etching prior to applying the universal adhesives used in this study does not influence the bond strength of glass fiber posts to root dentin.

Effect of proanthocyanidin on push-out bond strength between fiber post and root dentin- An in-vitro study

Aim: The aim of this study was to assess the influence of Proanthocyanidin (PA) application on bond strength of glass fiber posts to root canal dentin using self-etch adhesive luting system. Materials and Methods: Twenty single rooted mandibular premolars, freshly extracted for orthodontic purpose, were decoronated below the cementoenamel junction, and standardized to 14mm in length. Post space preparation was done upto No 3 Peeso reamer during which canals were irrigated with conventional irrigation protocol. Teeth were randomly divided into two groups (n=20 each) Group 1: Pre-treatment with PA and Group 2 served as the control group. Both Groups were restored with fiber posts bonded with RELYX U200 self-etch adhesive system. Teeth were then stored in distilled water for three months at 37° C. One mm slices were obtained and push-out bond strength testing was performed. Failure patterns were assessed under stereomicroscope at 20x magnification. Results: Individual bond strength values were calculated and statistically analysed with the chi-square test and independent-t-test. A statistically significant difference existed between the two Groups (p

Assessing the bond strength of Glass Fiber Reinforced Polymer (GFRP) bars in Portland Cement Concrete fabricated with seawater through pullout tests

Portland Cement Concrete (PCC) is the most used construction material worldwide and its use is expected to increase in the future. PCC intensively uses two main natural resources, namely aggregates and fresh water. The concrete industry consumes about 2 billion tons of potable water annually. Due to climate change, rapid population growth, and industrial activity, there is a scarcity of fresh water; by 2025 more than half of the world’s population will be living in water-stressed areas. In contrast, there is abundant seawater in the world, which represents about 97.5% of the total Earth’s water. However, the incorporation of seawater in PCC is a complex problem because the sulfate ions can affect the microstructure durability and the chloride ions can accelerate reinforcing steel corrosion, which can compromise the structural integrity. Glass Fiber Reinforced Polymer (GFRP) bars may be used as an alternative reinforcing material to avoid corrosion. This paper assesses the bond strength of two types of GFRP bars with either a sand-coating or spiral grooves using a standard pullout test. Control samples were prepared using concrete made with potable water and compared with companion specimens made with seawater. Parallel experimental programs were carried out in Chile and Canada, with a total of 70 test specimens. The results suggest that there is no statistically significant difference in the short-term (28 day) bond strength of GFRP bars in seawater concrete compared to normal concrete.

Glass fiber posts

Aim: Glass fiber posts are indicated in the rehabilitation of extensively damaged teeth; their cementation represents a critical step in restorative dentistry. The aim of this study was to quantify and compare the push-out bond strength of glass fiber posts cemented by conventional technique, two-step technique with luting agent and two-step technique associating bulk-fill composite and luting agent. Methods: Eighty maxillary bovine incisors were endodontically treated and divided into eight groups (n = 10) according to the luting agent (Rely X ARC and Duo-link) and cementation technique (conventional technique; two-step technique with luting agent; and two-step technique associating bulk-fill composite – Filtek Bulk-fill flow or Surefil SDR flow – and luting agent). Samples were submitted to pushout bond strength test, and the fracture pattern was evaluated through scanning electron microscope. Data were submitted to two-way ANOVA and Tukey’s test (α = 0.05). Results: When Rely X ARC was used, the conventional cementation technique obtained higher bond strength values than the twostep technique associated with Filtek Bulk-fill flow. When Duolink was used, the two-step technique associated with Filtek Bulk-fill flow presented higher bond strength values than the conventional technique. The most prevalent fracture patterns were adhesive between luting agent and dentin, and adhesive between bulk-fill composite and dentin. Conclusion: Two-step cementation technique associated with bulk-fill composite may be promising depending on the luting agent used.