Tensile Bond Strength Test Research Articles

Comparison of Tensile Bond Strength of Soft Denture Liner Material on Denture Base Resins

Aim: This study aims to evaluate the tensile bond strength (TBS) of a silicone-based soft denture liner material on denture bases produced via conventional, subtractive, and additive manufacturing techniques and examine the effect of aluminum oxide particle abrasion (APA) on TBS. Material and Methods: A total of 48 cylindrical denture base resin samples were manufactured using three different techniques: conventional, subtractive, and additive manufacturing. The samples were divided into two groups: control and APA. All samples were separated at the center, and the soft liner was applied to the corresponding surfaces. The specimens then underwent TBS testing. Data were analyzed using Two-way ANOVA and Bonferroni post hoc tests. Results: Two-way ANOVA results indicated a significant difference among the denture base resins, while no significant difference was found between the control and APA groups. The highest TBS was observed in the subtractive-manufactured APA group, while the lowest TBS was in the additive-manufactured APA group. Significant differences were found between the subtractive and additive-manufactured groups (p=0.022). Conclusion: This study demonstrates that TBS varies with the DB's manufacturing technique. While APA increased TBS in subtractive manufacturing, it had no statistically significant effect. Further research should explore different soft lining materials and consider in vivo conditions for more comprehensive insights.

Bonding mechanism and fracture behavior of cold-sprayed Fe-based amorphous alloy on 6061 Al alloy

Using cold spray technology to prepare amorphous alloy coatings can effectively prevent crystallization, thereby preserving the excellent properties of amorphous alloys. However, interfacial bonding significantly affects performance, such as weak bonding impacting the durability and stability of the coating. Therefore, in-depth study of the interfacial bonding mechanism is crucial for a comprehensive understanding of coating properties. This paper uses cold spray technology to prepare Fe-based amorphous alloy coating on 6061 aluminum alloy substrates. The bonding mechanisms at the particle/substrate, particle/particle, and coating/substrate interfaces are studied, and the fracture behavior in the tensile bond strength test is analyzed. The results show that the heat accumulation and the increase in strain rate generated by the particles impacting the substrate cause the viscosity of the amorphous alloy to suddenly decrease from 1.2×103 g·cm−1 s−1 to 8.4×10−1 g·cm−1 s−1. Increased fluidity and micro-friction accelerate the mixing of elements and form a metallurgical bond at the particle/substrate interface. Meanwhile, the oxides at the particle/particle interface are extruded, and the exposed fresh metal is subjected to a huge shear rate to promote atomic fusion. Tamping of the subsequent particles leads to further deformation of the deposited particles, forming a stronger metallurgical bond and mechanical anchoring at the particle/particle interface. In addition, the continuous impact of particles triggers dynamic recrystallization of the substrate, and the average grain size decreases from 14.28 μm to 1.39 μm. This fine-grained structure strengthens the mechanical anchoring of the coating/substrate interface. Furthermore, the bonding strength measured by the tensile test is determined to be 18.51 MPa. The main reasons for the final fracture occurring in the coating are the coating pores, cracks formed by shear bands accumulated in free volume, and the low adhesion oxide layer at the particle interface.

The Effect of the Water Flow Rate During Laser Irradiation on the Bond Strength of Glass Fiber Posts

Objective: This study aimed to investigate the effect of the water flow rate during laser irradiation on the bond strength of GFRC posts. Background: Due to the ablation mechanism, water molecules must be present in the target tissue for effective results with erbium lasers. Materials and methods: Sixty glass fiber posts were divided into six equal groups: control groups, sandblasting with 30 μm Al2O3 particles, 9.5% hydrofluoric acid (HF), and three different flow rates (1%, 50%, and 100%) laser groups (n = 10). Resin cement was applied to the surfaces of the fiber posts. Then, 1 mm thick sections were taken from each specimen and micro tensile bond strength test was applied. The data obtained were statistically analyzed by a one-way analysis of variance and Tukey’s HSD test. Results: According to the statistical analysis results, there was a significant difference between the bond strength values of all the groups (P < 0.001). The highest bonding value was obtained in the sandblasted group (12.25 ± 0.38) and the lowest in the control group (5.64 ± 0.6). After sandblasting, the highest value was observed in the laser applied group (10.57 ± 0.64) at 100% flow rate. Conclusions: As the water flow rate decreases in laser applications, the bond strength between the fiber post and resin cement decreases.

Influence of Immediate Dentin Sealing on Bond Strength of Resin-Based CAD/CAM Restoratives to Dentin: A Systematic Review of In Vitro Studies.

Immediate dentin sealing (IDS) is a method of improving the bond strength of indirect dental restorative materials to dentin and belongs to the biomimetic protocols of contemporary dentistry. The purpose of this systematic review was to evaluate the effect of IDS on the bond strength of resin-based CAD/CAM materials to dentin. PubMed and MEDLINE, Scopus, and the Web of Science were searched by two individual researchers, namely for studies that have been published in English between 1 January 2005 and 31 December 2023 in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. The inclusion criteria encompassed articles related to in vitro studies, measuring the bond strength through microtensile bond strength (μ-TBS), micro-shear bond strength (μ-SBS), tensile bond strength (TBS) or shear bond strength (SBS) tests after the use of the IDS technique. The included restorative materials comprised resin-based CAD/CAM materials bonded to dentin. A total of 1821 studies were identified, of which 7 met the inclusion criteria. A meta-analysis was not deemed appropriate due to the high level of diversity inthe publications and techniques. The use of IDS yielded higher bond strength outcomesin various experimental conditions and resin-based CAD/CAM materials. Overall, IDS in CAD/CAM restorations may contribute to better clinical outcomesand improved restoration longevity due to this property.

Visible light-activated curcumin-doped zinc oxide nanoparticles integrated into orthodontic adhesive on Micro-tensile bond strength, degree of conversion, and antibacterial effectiveness against Staphylococcus Aureus. An investigation using scanning electron microscopy and energy-dispersive X-ray spectroscopy

AimTo acquire a thorough comprehension of the photoactivated Cur-doped ZnONPs at different concentrations 0%, 2.5%, and 5% on the physical qualities, antibacterial efficacy, degree of conversion, and μshear bond strength between orthodontic brackets and the enamel surface. Material and MethodsAn extensive investigation was carried out utilizing a range of analytical methods, scanning electron microscopy (SEM) combined with energy-dispersive X-ray spectroscopy (EDX), Fourier-transform infrared (FTIR) spectroscopy, micro tensile bond strength (μTBS) testing, and evaluation of antibacterial effectiveness. Cur-doped ZnONPs at concentrations of 2.5% and 5% were blended with Transbond XT, a light-curable orthodontic adhesive. A control group without the addition of Cur-doped ZnONPs was also prepared. The tooth samples were categorized into three groups based on the weight percentage of NPs: Group 1 (control) with 0% Cur-doped ZnONPs, Group 2 with 2.5 wt% Cur-doped ZnONPs, and Group 3 with 5 wt% Cur-doped ZnONPs. The SEM technique was employed to analyze the morphological characteristics of Cur-doped ZnONPs and ZnONPs. The composition and elemental distribution of the modified Cur-doped ZnONPs were assessed using energy-dispersive X-ray spectroscopy. The effectiveness of NPs at various concentrations against S.Mutans was gauged through the pour plate method. DC of Cur-doped ZnONPs at a region of 1608 cm−1 to 1636 cm−1 for the cured area, whereas the uncured area spanned the same range of 1608 cm−1 to 1636 cm−1 was assessed. The Adhesive Remnant Index (ARI) approach was utilized to investigate the bond failure of orthodontic brackets, while a Universal Testing Machine (UTM) was utilized to test μTBS. The Kruskal-Wallis test was employed to investigate variations in S.mutans survival rates. To determine the μTBS values, analysis of variance (ANOVA) and the post hoc Tukey multiple comparisons test were used. ResultsThe maximum μTBS was given and documented in group 3: 5 wt% Cur-doped ZnONPs (21.21 ± 1.53 MPa). The lowest μTBS was given in group 2: 2.5 wt% Cur-doped ZnONPs (19.58 ± 1.27 MPa). The highest efficacy against S.mutans was documented in group 3 in which 5 wt% Cur-doped ZnONPs (0.39 ± 0.15). The lowest efficacy was seen in group 1 in which no Cur-doped ZnONPs were used (6.47 ± 1.23). The ARI analysis indicated that the predominant failure was between scores 0 and 1 among all experimental groups. Control group 1 which was not modified showed the highest DC (73.11 ± 4.19). ConclusionOrthodontic adhesive, containing 5% Cur-doped ZnONPs photoactivated with visible light exhibited a favorable impact on μTBS and indicated enhanced antibacterial efficacy against S.mutans. Nevertheless, it was observed that the addition of Cur-doped ZnONPs at different concentrations (2.5%,5%) resulted in a decrease in the monomer-to-polymer ratio compromising DC.

Effects of different surface treatments on surface topography and bond strength in the repair of fiber-reinforced dentin composite.

This study aimed to evaluate the effects of different surface treatments on the repair bond strength between a fiber-reinforced dentin composite and a posterior composite. Forty fiber-reinforced dentin composite resin blocks (4 mm × 4 mm × 4 mm) were separated into eight groups (n = 5) according to the surface preparation methods: (G1) negative control group, (G2) adhesive application, (G3) 50% dimethylsulfoxide (DMSO) application, (G4) 50% DMSO + adhesive application, (G5) 37% phosphoric acid etch + adhesive application, (G6) air abrasion + adhesive application, (G7) 37% phosphoric acid etch + 50% DMSO application + adhesive application, and (G8) air abrasion +50% DMSO application + adhesive application group. The composite surfaces were repaired in two layers with a posterior composite. Composite sticks were subjected to a micro tensile bond strength (μTBS) test. Fractured surfaces were evaluated using a stereomicroscope (×25). Short fiber-reinforced composite samples' surfaces were investigated by scanning electron microscope (SEM). Shapiro Wilk, one-way ANOVA, and Tukey HSD tests were used for statistical evaluation. The highest average (μTBS) values were observed in G8, whereas the lowest mean μTBS values were evident in the G1 group. Statistically significant μTBS values were found in all adhesive-applied groups when compared with the negative control group. Notably, the application of 50% DMSO without adhesive did not lead to a statistically significant increase in μTBS values. SEM images demonstrated that acid etching partially eliminated residues on the composite surface, while air abrasion had a detrimental effect on the integrity of fiber structures. In the repair of fiber-reinforced dentin composite with a posterior composite, adhesive application is an effective approach. The treatment of 50% DMSO without adhesive did not confer a statistically significant advantage, and the supplemental use of acid etch or air abrasion did not show an additional benefit compared to adhesive-only repairs. Adhesive application emerges as a potent and effective strategy for the repair of bur-roughened fiber-reinforced dentin composites. With its limitations, the study highlights the efficacy of adhesive-only repairs without the necessity for additional surface treatments.

The effect of repair protocols and chewing simulation on the microtensile bond strength of two resin matrix ceramics to composite resin

BackgroundTo assess the micro tensile bond strength (µTBS) of two resin matrix ceramic (RMC) blocks bonded to composite resin by using different repair protocols with and without chewing simulation (CS).Materials and methodsTwo resin matrix ceramic blocks (Vita Enamic and Lava Ultimate) were divided into 4 groups according to the surface treatments: Bur grinding (control), Bur grinding + silane, 9.5% HF acid etching, and 9.5% HF acid etching + silane. The single bond universal adhesive was applied on all specimens after the surface treatments according to the manufacturer’s instructions, it was administered actively on the treated surface for 20 s and then light cured for 10 s, followed by incremental packing of composite resin to the treated surface. Each group was further divided into 2 subgroups (with/without chewing simulation for 500,000 cycles). A micro tensile bond strength test was performed for each group (n = 15). The effect of surface treatments on the materials was examined by using a scanning electron microscope (SEM). The micro tensile bond strength (MPa) data were analyzed with a three-way ANOVA, the independent t-test, and one-way ANOVA followed by the Tukey post-hoc test.ResultsµTBS results were significantly higher for Lava Ultimate than Vita Enamic for all the surface treatment protocols with (p < 0.01). The chewing simulation significantly negatively affected the micro-tensile bond strength (p < 0.001). Bur grinding + saline exhibited the highest bond strength values for Lava Ultimate, both with and without chewing simulation. For Vita Enamic, bur grinding + saline and HF acid + saline showed significantly higher bond strength values compared to other surface treatments, both with and without chewing simulation (p ≤ 0.05).ConclusionBur grinding + silane could be recommended as a durable repair protocol for indirect resin matrix ceramics blocks with composite resin material.

Effect of Tea Tree Oil Addition to Denture Liners Against Candida albicans and Bond Strength to Acrylic Denture Bases.

To evaluate the effect of adding tea tree oil to denture liners on Candida albicans and bond strength to the acrylic denture base. Disc-shaped specimens were fabricated from silicone-based resilient liner (Tokuyama, Molloplast), acrylic-based hard liner (GC Reline), and acrylic-based soft liner (Visco-gel). Tea tree oil (TTO) was incorporated into the liners at varying concentrations (0% [control], 2%, 5%, 8%). C albicans were counted by viable colony count, and optical density (OD) was measured with a spectrophotometer. The tensile strength to heat polymerized acrylic denture base was measured in a universal testing machine. The compliance of the data to the distribution of normality was evaluated using the Shapiro Wilk test. Two-way ANOVA, Bonferroni correction, and paired sample t test were performed (α = .05). The addition of TTO into liners provided a significant decrease in the OD values (P < .001). The control groups of the liners presented the highest colony counts, whereas increasing TTO decreased the results (P < .01). According to tensile bond strength test, 8% TTO addition resulted in a significant decrease for Tokuyama (P < .01) and Molloplast liners (P < .05), while 2% TTO resulted in significance for GC Reline (P < .001). Denture liners containing increasing percentages of TTO presented lower amounts of C albicans colonies and decreased bond strength to the denture bases. When using TTO for its antifungal properties, the amount added should be carefully selected because the tensile bond strength may be affected.

Nanoparticle Augmentation of Adhesive Systems: Impact on Tensile Strength in Fiberglass Post Placement within Root Dentin.

BACKGROUND Modification of the glass fiber post (GFP) with titanium dioxide or silver particles can improve the durability and reliability of dental treatments for ensuring long-term success. This research assessed the tensile bond strength (TBS) of an adhesive system used for cementing GFPs into root dentin following the incorporation of nanoparticles of titanium dioxide (NTiO2) and silver (NAg). MATERIAL AND METHODS Sixty human maxillary canines were prepared to create a 10-mm intra-radicular space for post placement from the cementoenamel junction. The specimens were randomly allocated into 2 groups (a non-thermocycling group and a thermocycling group). Each group was divided into 3 subgroups (10 samples each) according to the adhesive system used (adhesive system devoid of any addition, adhesive system including 1% NAg, and adhesive system infused with 1% NTiO2). TBS tests were conducted and recorded in MPa using a Universal Testing Machine, with an axial load applied at a rate of 0.5 mm/min until failure. The TBS for both groups (non-thermocycling and thermocycling) was measured in megapascals (MPa), and the failure type was recorded. The data were statistically analyzed using one-way analysis of variance (ANOVA) and Tukey's test with P.

Comparative Investigation of Mechanical Properties of Ball Attachment Manufactured from Different Alloys and Surface Improvement Processes

The retaining system commonly used in overdenture prostheses is the ball attachments, which are deformed over time, which can affect the retention and stability of the prosthesis. The aim of this study is to research the physical properties of the ball attachments which are made of different alloys and used for surface treatment. In our study, ball attachments produced from different alloys (Grade 4, Grade 5, Grade 23, CoCr) and applied various surface treatments (no surface treatment, anodisation, micro-arc oxidation coating) were used. Samples were prepared in the laboratory environment and exposed to the thermal cycle, which corresponds to a 5-year aging process, by means of chewing simulators. The changes in the surface properties of the ball attachments as a result of the aging process were evaluted with scanning electron microscopy (SEM-EDX) and X-ray diffractometry (XRD). Considering that the deformation in the matrix and the patrix would affect the retention resistance, tensile bond strength test was applied in a universal test device to measure this resistance. Values were recorded in Newtons and Megapascals. In order to detect the wear on the patrix, weight measurements were made on precision scales. Values were recorded in milligrams (mg). The data were analysed using the SPSS programme. As a result, loss of retention and wear were observed on all ball attachments and matrix. Retention and weight loss were seen the most in the titanium grade 4 group and the least in the CoCr group. No significant difference was found between the other groups.

The Effect of Titanium Anodization on the Bond Strength of 10-methacryloyloxydecyl dihydrogen phosphate (10-MDP) Resin Cement.

To examine the effects of anodization and different surface modifications of titanium on bond strength to 10-methacryloyloxydecyl dihydrogen phosphate (10-MDP) resin cement. Grade 5 titanium alloy disks (n = 160) were assigned to one of five prebonding surface treatment study groups (polished; polished and anodized; polished, etched, and anodized; sandblasted; sandblasted and anodized). Disks were adhesively bonded with 10-MDP resin cement (Panavia 21; bonding area: 3.3 mm in diameter) to composite resin cylinders. In each study group, tensile bond strength tests were conducted after 24 ± 1 hours and after 6 months (180 ± 2 days) of water storage (n = 16 specimens per water storage subgroup). Debonded specimens were stereomicroscopically analyzed to determine their fracture mode. Statistics included one-way and multifactorial ANOVA and Tukey post hoc tests (α = .05). Anodization and water storage did not significantly (P ≥ .389) affect tensile bond strength. Although subgroups of polished samples had significantly (P ≤ .031) lower bond strengths (subgroup mean values: 20 to 26 MPa) than etched or sandblasted samples (subgroup mean values: 29 to 33 MPa), they nonetheless exceeded the empirical threshold of 10 MPa used as a criterion for clinical recommendation. The fracture mode of all test specimens was predominantly cohesive. Anodization of titanium surfaces can be performed without weakening the adhesion of 10-MDP-based resin cement to titanium.

Assessment of the Impact of Adhesive and Wires Types on the Tensile Bond Strength of Fixed Lingual Retainers Used in Orthodontics: An In Vitro Study

Introduction: We aimed to assess the impact of adhesive and wires types on the tensile bond strength of fixed lingual retainers. Methods: A total of 160 intact bovine teeth were collected, cleaned, stored in 25% sodium hypochlorite, and randomly assigned to two groups based on the adhesive type: a two-step adhesive and a one-step adhesive. Each group was further divided into four subgroups based on the type of lingual retainer wire, which included (A) 8-strand braided stainless steel wire, (B) three-strand titanium retainer wire, (C) stainless steel chain, and (D) fiber-reinforced retainer. A tensile bond strength test was conducted using a universal testing machine at a controlled speed of 10 mm/min. Result: The 8-strand braided stainless steel wire and stainless steel chain bonded by one-step self-priming adhesive showed significantly higher tensile bond strength (P &lt; 0.001). The adhesive wire significantly affected the tensile bond strength (P &lt; 0.001). Conclusion: Within the limitations of this in vitro study, it can be concluded that stainless steel wire and chain bonded by one-step self-priming adhesive showed higher tensile bond strength.

Are Universal Adhesives Effective for Bonding to Zirconia in the Long Term?

The bond capacity of universal adhesives should be comparable to a specific primer for zirconia. Thus, this study evaluated the bond strength to zirconia of four universal adhesives and a zirconia primer over long-term storage. The surfaces of 75 samples of zirconia were sandblasted with 50 µm aluminum oxide particles and then divided into groups (n = 15): G1 - Single Bond Universal (SBU); G2 - All Bond Universal; G3 - Peak Universal Bond; G4 - Ambar Universal (AU), and G5 - Z-Prime Plus (ZP). A cone of resin composite was constructed on the applied materials. The samples were submitted to a tensile bond strength test after 24 h using a universal testing machine. Then, the remaining materials were removed from the sample surfaces, and the surfaces were polished and sandblasted again as previously described to obtain the same groups. These new samples were stored in distilled water at 37°C for 12 months and then submitted to a tensile bond strength test. The data were analyzed by two-way analysis of variance and Tukey's test (α =0.05). The material factor (P = 0.001) and the storage factor (P = 0.001) were significant, and the interaction was not significant (P = 0.117). According to Tukey's test, bond strength mean values (in MPa) followed by distinct letters were significantly different. After 24 h, G5 = 21.12 A, G1 = 20.55 A, G4 = 19.19 AB, G2 = 14.22 B, and G3 = 8.44 C. After 12 months, G1 = 7.37 A, G5 = 5.61 AB, G4 = 4.97 B, G2 = 3.32 C, and G3 = 1.93 D. After 12 months of storage, all groups' bond strength significantly decreased. SBU and AU had bond strengths comparable to ZP after 24 h. No material resisted water degradation.

Comparison of bond strength to three restorative materials after contamination and the use of two cleaning agents

Statement of problemScientific data on the decontamination effectiveness of a newly introduced cleaning agent are lacking. PurposeThe purpose of this in vitro study was to evaluate and compare the tensile bond strength (TBS) of 3 different restorative bonding surfaces after contamination with saliva following different cleaning protocols. Material and methodsA total of 192 disk specimens were made out of 3 materials (n=64); Katana Avencia (A), Katana Zirconia (Z), and e.max CAD (L). The bonding surfaces of all disks were polished, steam cleaned, and then pretreated by following the recommended protocol for each material. The specimens of each group were divided into 4 subgroups (n=16). The first subgroup served as the reference (R), where no contamination was applied. The 3 other subgroups were contaminated with saliva and subsequently rinsed with water for 20 seconds and dried with oil- and water-free air spray. They were then either not treated with any cleaning method (0), cleaned with Katana Cleaner (K), or cleaned with Ivoclean (I). The bonding surfaces of the specimens were perpendicularly luted to plexiglass tubes filled with dual-polymerizing composite resin (Clearfil DC Core) with resin cement (Panavia V5) after the recommended surface conditioning. Each subgroup was further subdivided into 2 groups: stored in 37 °C water for 3 days or subjected to thermal-cyclic loading for 150 days with 37 500 thermal cycles (7500 per month), temperature 5 to 55 °C, and dwell time of 30 seconds. All specimens were subjected to TBS testing in a universal testing machine. Three-way ANOVA was applied. A significant interaction (P<.01) was detected between the 3 different variables (material, treatment, aging). After significant interactions had been revealed by 3-way ANOVA, additional statistical analysis was performed by using separate 2-way ANOVAs, then separate 1-way ANOVAs followed by the Tukey-HSD test for post hoc pairwise comparisons among groups (α=.05 for all tests). All specimens underwent failure mode analysis after TBS testing ResultsAll specimens survived the storage with thermocycling except for group Z-0, where all specimens debonded during thermocycling. The mean ±standard deviation TBS values ranged from 18.3 ±5.3 MPa to 34.0 ±5.4 MPa after 3 days and from 6.7 ±5.5 MPa to 26.9 ±5.4 MPa after 150 days. ConclusionsContaminated groups that did not receive any cleaning had significantly lower TBS. Thermocycling had a negative effect on the TBS but was not statistically significant for all groups. Using the same cleaning method, the restorative material did had a significant effect on the TBS after 150 days.

Evaluation of the Polymer Modified Tack Coat on Aged Concrete Pavement: An Experimental Study on Adhesion Properties

This study addresses the challenges of overlaying old concrete pavement with asphalt by introducing a new trackless tack coat material containing polymer. The aim is to enhance the durability of asphalt concrete overlay pavement on old cement concrete pavement. It contributes to the development of improved construction techniques for pavement rehabilitation and highlights the need for reliable adhesion performance evaluation based on different spray amounts and surface conditions. Additionally, to evaluate the effect of the adhesion performance based on the spraying amount, a tensile adhesion test was conducted by applying spray amounts of 0.30, 0.45, and 0.60 l/m2 on different surface conditions. The basic and adhesion performances of the polymer-modified tack coat material are evaluated through direct tensile and shear bond strength tests. The test outcomes demonstrated that the newly developed polymer-modified tack coat material had considerably greater adhesion strength compared to the traditional rapid-setting products. Its adhesive strength was 1.68 times higher on concrete and 1.78 times higher on asphalt. The new trackless tack coat material exhibited an adhesion performance of 1.05 MPa in direct tensile strength at 0.45 l/m2, which was 1.21 times higher than the rapid-setting tack coat. Results also confirmed that the new tack coat material exhibits values 1.90 times greater than the conventional rapid-setting tack coat material in shear bond strength, respectively. By simulating the process of separation and re-adhesion of pavement layers caused, the new tack coat material shows a tensile adhesion strength of 63% of the original state, which is advantageous for securing the durability of the pavement. Overall, the newly developed polymer-modified trackless tack coat has been shown to effectively enhance the adhesion performance between pavement layers without process delay, highlighting the potential of the new tack coat material to enhance the durability of asphalt concrete overlay pavement on old cement concrete pavement.

Adherence of Brazilian dimension stones by mortar adhesion: influence of temperature

The influence of temperature variation on the adherence of granite slabs was simulated by a set of TBS tensile bond strength tests carried out using three types of rocks of established commercial use and with good technological qualities, known as “Branco Desireé”, “Vermelho Capão Bonito” and “Cinza Andorinha”. Specimens of these materials were fixed with two types of adhesive mortars, one commercial and the other produced in the laboratory, with white cement CPI. After the standardized cure, 186 TBS tests were carried out in 5 temperature ranges laboratory-controlled, ranging from 23 °C to 60 °C. The test results showed the temperature increase implies the loss of tensile strength. The commercial mortar presented TBS final values lower or nearby to 1 MPa, the standard threshold for ceramic slabs. The mortar prepared with white cement showed better performance, with adherence values above the 68% mentioned limit. This expressive result recommends the continuation of research with other types of rocks fixed with mortar prepared with white cement. The microstructure behavior of the material sets subjected to adherence tests was also investigated. The inspections showed clear contact between the stone plates (with both rough and smooth contact surfaces), without the occurrence of reaction edges or pervasion of the mortar in the stone. Anchoring, therefore, took place only in the contact between the standard substrate and mortar.

Performance of Dental Cements Used for Bonding Zirconia Crowns with Titanium Implants Embedded in an Innovative Bi-Layered Artificial Bone

This study aimed to investigate four dental adhesive cements and develop a new method for constructing a bi-layered bone holder for implant testing. HahnTM Tapered Titanium Implants (Glidewell Laboratories) were embedded in mono- and bi-layered holders, and the implant components were assembled. First molar zirconia crowns and crowns for the tensile bond strength test were milled and sintered. Three self-adhesive resin cements (SARC) and one resin-modified glass ionomer (RMGI, Glidewell Laboratories) cement were used to cement the crowns on the abutment. Tensile bond strength, compressive load, and oblique load tests were performed on the implants. The Glidewell Experimental SARC (GES, Glidewell Laboratories) and RMGI cements had the highest tensile bond strength after thermocycling. The implant assemblies with these two cements had the highest mean compressive strength after thermocycling. Under oblique load, the implants with Denali (Glidewell Laboratories) and GES had the highest strength before thermocycling. However, after thermocycling, Dencem (Dentex) and RMGI had the highest strength under an oblique load. The GES cement and RMGI cement had a better overall performance with zirconia crowns and titanium abutments. In addition, a novel technique for constructing an artificial, bi-layered bone holder was successfully developed to mimic the natural structure of the jawbone.

Relationships between the surface roughness of Brazilian dimension stones and the adhesion to mortars

The effect of different surface roughness for ceramic and metals on their adhesive bond strength is widely studied in the field of tribology, but still little investigated for stone claddings, which are natural and quite heterogeneous materials. The main objective of this study was to investigate the relationships between the surface roughness of ornamental stone slabs and their adhesion to mortars were determined by TBS tensile bond strength tests, including observation of types of failure in each test. Slabs with different roughness of the migmatitic stone, commercially known as in Brazil "Jacarandá Rosado", were fixed with two types of adhesive mortars, one commercial and the other produced in the laboratory (here referred to as “PM” mortar). Average TBS adhesion values were higher for the rougher plates, as expected, since in this condition there is a larger exposed surface of the minerals, resulting in a greater number of electrochemical charges available to interact with the adhesive mortars. In quantitative terms, the results indicate average values of 1.39 MPa and 1.16 MPa, respectively, for the higher and lower roughness of specimens fixed with Commercial mortar. Regarding the adhesion for PM mortar, values obtained in specimens with smooth, moderately rough and rough surfaces, respectively, were, on average TBS of 2.06 MPa, 1.42 MPa and 1.47 MPa, values higher than for the CM mortar. Importantly, in these last two test conditions, all failures occurred in the stone, indicating that the PM mortar adhered very well to rougher surfaces, i.e., the stone and the standard substrate. So, it is plausible to consider that TBS values of the PM Mortar should be, in practical terms, higher than measured in the tests, since they reflected more conditions of the rock than the mortar. Such information indicates that detailed evaluation of the types of failure in the adhesion tests was important to corroborate the better TBS results for the mortar prepared in the laboratory with CPV-ARI cement.

Investigation of the effect of different surface treatments for preventing detachment of polyetheretherketone and titanium attachment matrix housings in overdentures: An in vitro study.

The attachment matrix housing (AMH) of implant overdentures is not chemically bonded with acrylic resins. Therefore, AMH may lose due to insertion and removal forces. This study aims to investigate the effects of different surface treatments to reduce the detachment of AMH and to compare the adhesion of the AMH used in implant-supported overdentures made of different materials with the reline acrylic resin. Titanium and polyetheretherketone (PEEK) AMHs were separated into four surface treatment groups; no treatment, airborne-particle abrasion (APA) applied, universal bond (UB) applicated, APA, and UB applicated. Eight millimeters in diameter and ten millimeters tall straws were used to restrain the reline acrylic resin prepared according to the manufacturer's instructions and the resin was injected onto the surface-treated AMH. After the polymerization was completed, the universal testing machine performed the tensile bond strength (TBS) test with a fishing line passed through the acrylic resins. TBS data were analyzed with two and one-way ANOVA and Tukey HSD post hoc tests (α =0.05). According to the two-way ANOVA results, titanium AMHs (103.78 ± 45.98 N) showed higher TBS than PEEK AMHs (67.81 ± 28.61 N). UB applicated titanium groups showed significantly increased TBS values. Using titanium AMHs may be a better choice in situations where clinical aesthetic expectations are unimportant for adhesion to reline acrylic resins. The UB resin significantly increased the bonding of the titanium AMHs with reline resins. The application of UB resin to titanium housings can be easily applied in a clinical situation and can reduce the detachment of the titanium AMHs.

Evaluation of tensile adhesion strength in mortar for coating with incorporation of crushing sand

The use of crushed sand, a by-product generated in quarries during the process of manufacturing crushed stone used in civil construction, can reduce the consumption of natural sand, reducing the environmental impact of the extraction of this material. In this sense, this research aims to evaluate the influence of replacing natural sand with crushed sand on the tensile bond strength of mortars. Mortars were made with crushed sand from quarries in the region of Bauru/SP, performing 3 percentages of substitution, in mass, of natural sand by crushed sand: 10%, 20% and 30%, plus a reference with 100% sand natural, totaling 4 strokes. All mortars were made in accordance with ABNT NBR 13276/2005. The performance of the mortars was evaluated through the tensile bond strength test, as recommended by the ABNT NBR 13528/2019 standard. In the end, it can be said that it is feasible to use crushed sand to replace natural sand in the percentage of up to 20% for making mortars for coating external walls, which showed the best adhesion results. It was also found that, for internal coating, it is possible to use up to 30% of crushed sand, without compromising the performance of the mortar.