Types Of Resins Research Articles

Evaluating the color stability of 3D-printed resins against various solutions.

The purpose of this study was to investigate the effect of different solutions on the optical behavior of two types of 3D-printed resin (Detax and Asiga). The samples were randomly divided into 4 groups of cola, orange juice, tea and artificial saliva (control group) in the form of 14 x 10 mm blocks with a thickness of 1.5 ± 0.3 mm (10 samples in each group). By spectrophotometric device, the color of the examined samples was recorded in the CIE system and in three parameters *L (brightness), a* (red-green) and b* (blue-yellow) as the initial record. The color difference of the samples was recorded on 7 and 30 days after immersion as a secondary record. After that, using the formula, the color difference (ΔE) were calculated. T-test also was used to analyze the data. There was no significant difference between the amount of ΔE on 7th and 30th days after exposure to artificial saliva and cola and on 7th days after exposure to orange juice and tea. But on the 30th day, a significant difference was found in orange juice and tea drinks (p<0.05), so that the value of ΔE in Asiga printer was lower than Detax. ΔE changes in orange juice solution were more than other drinks. On the 30th day of immersion in tea drinks and orange juice, Asiga printer had significantly less color difference than Detax printer.

The Study of Some Mechanical Properties of Some Composite Materials with Different Types of Matrices and Reinforcement from Chromat-type Isophthalic Resin Granules NPG

Using the experimental determinations obtained on the basis of compressive stress, some mechanical properties were studied for composite materials with the matrix of three types of resin, epoxy, unsaturated polyester and hybrid based on Dammar natural resin, which was reinforced with isophthalic resin granules NPG (Neopentyl Glycol) Chromat Kayan / Javari / Payette type. The stress-strain diagrams, compressive yield strength, compressive strength and modulus of elasticity in uniaxial compression were obtained. With the EDS analysis, the graphical distribution of the atomic spectra of the elements identified in the hybrid resin was determined and the image of the fracture surface of a hybrid resin specimen was presented based on the stereomicroscopic analysis (SEM).

About Some Mechanical Properties Regarding Sandwich Samples Reinforced with Poplar Strips and the Core from Crushed Corn Cobs with Hybrid Dammar-Based Matrix

In this research some composite materials built in sandwich type style are studied. The lower and upper layers, that reinforce the samples, are made from poplar strips. The core is made from crushed corn cob and the adhesion of all parts (layers and core) is made by using hybrid resins based on a combination from dammar resin and the synthetic acrylic one (with its hardener). The static and dynamic mechanical behaviour by testing the samples to tensile and bending were studied. Two types of hybrid resins were used: one abbreviated as type B with the percentage of 60% dammar and 40% acrylic resin with hardener and one abbreviated as type C with the percentage of 65% dammar and 35% acrylic resin with hardener. A general conclusion from this study it was: the mechanical properties decrase with the dammar percentage increase. This fact can be explained by the decreased mechanical properties of the natural dammar resin compared to the synthetic acylic on

Effect of airborne particle abrasion treatment of two types of 3D-printing resin materials for permanent restoration materials on flexural strength.

This study aimed to assess the effects of airborne-particle abrasion (APA) on the flexural strength of two types of 3D-printing resins for permanent restoration. Two types of 3D printing resins (urethane dimethacrylate oligomer; UDMA, ethoxylated bisphenol-A dimethacrylate; BEMA) constituting different components were printed. The specimen surfaces were subjected to APA using 50 and 110µm alumina particles under different pressures. The three-point flexural strength was measured for each surface treatment group, and a Weibull analysis was performed. Surface characteristics were analyzed via surface roughness measurements and scanning electron microscopy. Dynamic mechanical analysis and nano-indentation measurements were limited to the control group. The three-point flexural strength according to the surface treatment was significantly lower in the UDMA group for large particle sizes and at high pressures; the BEMA group demonstrated low flexural strength for large particle sizes regardless of the pressure. After thermocycling, the flexural strengths of UDMA and BEMA significantly decreased in the group subjected to surface treatment. The Weibull modulus and characteristic strength of UDMA were higher than those of BEMA under different APA and thermocycling conditions. As the abrasion pressure and particle size increased, a porous surface formed, and the surface roughness increased. Compared with BEMA, UDMA featured a lower strain, greater strain recovery, and a negligible increase in modulus according to strain. Thus, surface roughness increased with the sandblasting particle size and pressure of the 3D-printing resin. Hence, a suitable surface treatment method to improve adhesion can be determined by considering physical property changes.

Wear of Bulk-fill Composite Resins After Thermo-mechanical Loading.

Wear of conventional composite resin presented many challenges when restoring posterior teeth and resulted in clinical complications. Bulk-fill composite resins have been proposed as a more suitable and wear-resistant alternative. To evaluate and compare the volumetric wear (mm3) of bulk-fill composite resins to a conventional composite resin and enamel after thermo-mechanical loading. Five composite resins (n=10) were evaluated: four bulk-fill composite resins (Filtek One Bulk Fill [3M Oral Care], Tetric EvoCeram Bulk Fill [Ivoclar Vivadent], Tetric PowerFill [Ivoclar Vivadent], SonicFill 3 [Kerr Corp]); and one conventional composite resin (Filtek Supreme Ultra [3M Oral Care]). Enamel from recently extracted human teeth was used as a control. Specimens were subjected to a 2-body volumetric wear evaluation using a chewing simulator (CS-4.8, Mechatronik). Disc-shaped specimens (10 mm in diameter × 3 mm in thickness) received 500,000 load cycles against steatite antagonists while simultaneously thermocycled (5000 cycles, 5-55°C). Volumetric wear (mm3) was measured using the Geomagic Control X software (3D Systems) based on digital scans of the specimens obtained before and after thermo-mechanical loading, with a Trios 3 (3Shape) digital scanner. Scanning electron microscopy analysis of wear facets and composite resin filler shape and size was performed. Volumetric wear was statistically analyzed using the one-way ANOVA and Tukey's post-hoc test (α=0.05). All tested composite resins wore at rates significantly higher than enamel (p<0.05). The mean volumetric wear of the composite resins ranged from 1.01 mm3 to 1.48 mm3, while enamel had a mean volumetric wear of 0.25 mm3. Bulk-fill composite resins showed higher wear resistance than the conventional composite resin (p<0.05). Bulk-fill composite resins showed higher wear resistance than the conventional composite resin, and both types of composite resin were not as wear-resistant as enamel.

3D printed heterogeneous cation exchange membrane processed using stereolithography

AbstractMembrane chemistry belongs to the field in which 3D printing can advantageously also be used because of enabling the production of prototypes with precisely defined dimensions. The presented work aimed to develop new polymeric compositions for heterogeneous cation exchange membranes manufactured using stereolithography (SLA) from commercially available materials. Three types of photo‐curable thermoset resins (acrylic resin and two types of epoxy resins) were used as polymer matrixes in combination with strong acid cation exchange resin (CER) powder. The membrane production consisted of several stages, namely mixing the photo‐curable resin with finely ground CER powder, processing using SLA, and appropriate post‐curing using UV light and elevated temperature. The work aimed to monitor the influence of the photo‐curable resin type and post‐curing on the microstructural, electrochemical, and mechanical properties of resulting membrane objects. The results revealed that heterogeneous cation exchange membranes could be processed using SLA from the mixture of the acrylic photo‐curable resin and CER powder (weight ratio of 60/40) without the need for post‐curing. These products exhibited high permselectivity (93%), high ion exchange capacity (2.23 meq⋅g−1), and sufficiently low electrical resistance (2200 Ω⋅cm), which predetermines them for efficient electrophoretic separation.

Effect of additional polymerization process on color change in composite resins hold in different solutions

Aims: In this study, it was aimed to compare the amount of coloration of composite resins with different filler content by keeping them in various coloring solutions after standard and additional polymerization processes. Methods: Three types of composite resins with different contents were used in our study: Filtek?? Z250 (3M ESPE), G-aenial Anterior (GC) and Neo Spectra?? ST HV (Dentsply Sirona). A total of 240 composite resin samples were prepared, 10 (n:10) for each group, using molds with a depth of 2 mm and a diameter of 8 mm. The polymerization of the samples was carried out for 20 seconds using a LED curing device (Woodpecker Led-G, China). After finishing and polishing was done with Super-Snap (Shofu, JAPAN) finishing discs, additional polymerization was performed on half of the samples. Then, all samples were kept in distilled water for 24 hours at 37°C in an oven (Microtest MST 55, Ostim Ankara). The first color measurement of the samples extracted from distilled water was made with a spectrophotometer device [VITA Easyshade V (Vita Zahnfabrik, Bad Sackingen, Germany)]. After the first measurement, the samples placed in 100-mesh plastic containers were placed on bags of tea (Lipton, Rize, Turkey), filtered coffee (Nescafe Classic, Nestle, Turkey), mouthwash containing chlorhexidine (Kloroben mouthwash, Drogsan, Ankara, Turkey) and red wine (Buzbağ). Classic, Öküzgözü-Boğazkere, 2021 Elazığ, Turkey) was added. One week later, the samples were removed from the vacuum furnace, washed in distilled water, and the second measurements were made. Results: A statistically significant difference was found between the coloration values caused by the solution groups (p&lt;0.05). It was observed that the solution causing the most color change was wine, followed by coffee and tea, respectively. Although there was no statistically significant difference between the coloration values caused by the composite groups (p&gt;0.05), it was determined that the composite resin material with the lowest color change was the microhybrid-based Filtek?? Z250. Although there was no statistically significant difference between the coloration values caused by standard and additional polymerization (p&gt;0.05), it was determined that the additional polymerization process affected the color change amount of the materials positively. Conclusion: According to the findings of this study; Among the coloring solutions used, it was observed that the solution causing the most coloration in composite resins was red wine, followed by coffee, tea and mouthwash containing chlorhexidine, respectively. However, it was concluded that the addition polymerization process reduces the coloration of the composite resins.

An In-Vitro Comparison of Shear Bond Strength and Adhesive Remnant Score Between Two Color Change Adhesives in Orthodontic Bonding With Reduced Curing Time Using Different High-Intensity Light Emitting Diode Units.

This study aims to determine the effect on shear bond strength (SBS) and adhesive remnant score between two color change adhesives (CCAs) with reduced curing time using different high-intensity light emitting diode(LED) units. A total of 108 human first maxillary premolar teeth were randomly allocated into three principal groups (n = 36) based on the type of adhesives used. The adhesives include two CCAs: TransbondPlus Color Change Adhesive (3M, St. Paul, MN, USA) and Grengloo (Ormco, Orange, CA, USA), and the conventional tooth-colored adhesive: TransbondXT (3M). Each principal group was further divided into three sub-groups (n = 12 each) based on the curing time and type of high-intensity LED units used for bonding the stainless steel brackets. Woodpecker iLED Light Curing Unit (Guilin Woodpecker Medical Instrument Co., Ltd., Guilin, China) was cured for three and six seconds, and the ELIPARS10 LED Curing Light (3M) was cured for 20 seconds. Bonding of the brackets was done in a standardized manner following the manufacturers' instructions. All the samples were submerged in distilled water at 370C for 24 hours. SBS testing was performed using an Instron machine, and adhesive residue on the debonded surface was examined and scored using a stereomicroscope. Statistical analysis was conducted using one-way ANOVA and Tukey's post-hoc test. The results showed significant differences in SBS based on curing time and the type of adhesive resin used. The six seconds curing group exhibited the higher SBS values (15.5 - 22.82 Megapascals [MPa]) followed by the 20 seconds (12.17 - 18.14 MPa) and three seconds (11.31 - 11.74 MPa) groups. Grengloo adhesive demonstrated the highest SBS values among the three types of adhesives. The predominant adhesive remnant scores were 2 and 3. Grengloo adhesive demonstrates superior bond strength compared to Transbond Plus and Transbond XT. Both Transbond Plus and Grengloo adhesives experience bond failure within the adhesive layer, regardless of the curing intensity or time.

Research on Rotor Sleeve Winding Techniques for High-Speed Permanent Magnet Motors via NOL Ring Testing

Surface-mounted high-speed permanent magnet motors are known for their small size, high power factor, and reliable control and operation. However, these motors may have low mechanical strength and weak tensile strength in their rotor magnet, which necessitates the adoption of an external sleeve for protection. Currently, carbon fiber composite sleeves are garnering increasing attention for their durable and reliable protective capabilities. Despite the apparent benefits of carbon fiber composite protective sleeves, systematic research on the relevant parameters such as winding angle, fiber type, resin type, winding tension, and curing method is currently lacking in the literature for high-speed permanent magnet motors. In this context, this paper employs an innovative approach, utilizing the Taguchi method, the National Ordnance Laboratories (NOL) ring failure test, and a resin content test, to investigate the winding process parameters of carbon fiber composite protective sleeves for high-speed permanent magnet motors. The results indicate that the tensile strength of the composite sleeve with a winding angle of 45 and 30° is reduced by 20~25% compared with the sleeve with a pure hoop winding angle. The loss of strength caused by the manufacturing process accounts for 30%. When the wet winding tension is 130 N, the tensile and shear strength of the sleeve decreases by 13 and 12%, respectively, compared with that of 70 N. When the dry winding temperature rise rate is 3 min/°C, the strength of the sleeve decreases by 16% compared with that of 1 min/°C. For a small-thickness sleeve with a thickness of 1.5 mm, two-layer curing can increase the tensile strength of the sleeve, while three-layer curing or more can decrease the strength. By studying the process parameters of the sleeve, this article prepared a composite sleeve for a high-speed permanent magnet motor with a line speed of 200 m/s. This study provides a comprehensive analysis of the manufacturing process parameters of the rotor sleeve, which is helpful for the design and performance optimization of high-speed permanent magnet motors.

Analysis of hydrocarbon solvents for the removal of various types of asphalt, resin and paraffin deposits

In this work the physical-chemical properties of asphaltene-resin-paraffin deposits are studied. Their component composition was determined. The results obtained are the basis for the selection of effective solvents and the choice of the method of removing deposits from oil reservoirs. Two hydrocarbon solvents with the brands “TSK А” and “TSK B” were tested. The solvent ability of solvents was tested.

Comparison of accuracy cone-beam computed tomography and digital bitewing radiography for detection of recurrent caries under various restorative materials: in vitro study.

The aim of this study was to compare and evaluate diagnostic accuracy of two different CBCT scan modes and digital bitewing radiography for detection of recurrent caries under five different restorative materials, and determine the relationship between the types of restorative materials. In this in vitro study, 200 caries-free upper and lower premolars and molars were selected. A standard deep Class II cavities was created in the middle of the mesial surface of all teeth. In 100 teeth of the experimental and control groups, secondary caries was artificially demineralized. All teeth were filled with five types of restorative material including two types of conventional composite resins, flow composite resin, glass ionomer and amalgam. The teeth were imaged with high resolution (HIRes) and standard CBCT scan modes and digital bitewing. The AUC, sensitivity, specificity and areas under the ROC curve were calculated and verified through SPSS. CBCT technique was the best option in diagnosing recurrent caries. The diagnostic accuracy and specificity of HIRes CBCT scan mode was significantly higher than standard mode (P = 0.031) and bitewing (P = 0.029) for detection of recurrent caries, especially under composite group. There were no significant differences in accuracy value of bitewing and standard CBCT scan mode. CBCT showed higher accuracy and specificity on the detection of recurrent caries which was more accurate than bitewing radiography. The HIRes CBCT scan mode achieved the highest accuracy and performed the best in recurrent caries detection.

Ion Exchange Resin and Entrapped Candida rugosa Lipase for Biodiesel Synthesis in the Recirculating Packed-Bed Reactor: A Performance Comparison of Heterogeneous Catalysts

Ion exchange resins and immobilized lipase as heterogeneous catalysts are used to synthesize biodiesel for alternative fossil fuels. The use of ion exchange resins in the solid and activated phase can ease the separation process. Furthermore, resins can be reactivated and used repeatedly, reducing the need for catalysts. On the other hand, an immobilized enzyme is biodegradable and can catalyze the transesterification process to produce biodiesel with a lower alcohol-to-oil ratio, minimizing side reactions and impurities. Therefore, the catalysts used in this study are ion exchange resins, such as Lewatit MP-64, Amberlite IRA410Cl, and Diaion PK208LH, as well as immobilized Candida rugosa lipase. By using vegetable oil as a feedstock and methanol for the transesterification, biodiesel production was carried out in a packed bed reactor. The present study aims to investigate the optimum process parameters, including the concentration of resin and enzyme, resin activation time, resin types, flowrate, and stability of resin and enzyme on the biodiesel yield. The results showed that the optimum conditions for biodiesel production with ion exchange resin were 4 g of resin, activated for 3 h, and synthesized for 3 h; Lewatit obtained a biodiesel yield of 94.06%, Amberlite obtained 90.00%, and Diaion obtained 73.88%. Additionally, the stability test of the reactivated Lewatit resin showed that it still has the capability of producing biodiesel with a yield of more than 80% after three regeneration cycles. In contrast, Candida rugosa lipase as was immobilized by entrapment in sodium alginate before being used in the biodiesel production for 12 h. The results showed that lower flowrate in enzymatic biodiesel synthesis produced a higher amount of biodiesel, of up to 71.1%. Nonetheless, immobilized lipases can be used up to three times without a significant loss in biodiesel yield.

Sustainability Assessment of the End-of-Life Technologies for Biocomposite Waste in the Aviation Industry.

Biocomposites have emerged as promising alternative materials for the aviation industry. However, there is a limited body of scientific literature addressing the end-of-life management of biocomposites. This article evaluated different end-of-life technologies for biocomposite recycling in a structured, five-step approach applying the innovation funnel principle. First, ten end-of-life (EoL) technologies were compared in terms of their circularity potential and technology readiness levels (TRL). Second, a multi-criteria decision analysis (MCDA) was carried out to find out the top four most promising technologies. Afterwards, experimental tests were conducted at a laboratory scale to evaluate the top three technologies for recycling biocomposites by analysing (1) three types of fibres (basalt, flax, carbon) and (2) two types of resins (bioepoxy and Polyfurfuryl Alcohol (PFA) resins). Subsequently, further experimental tests were performed to identify the top two recycling technologies for the EoL treatment of biocomposite waste from the aviation industry. Finally, the sustainability and economic performance of the top two identified EoL recycling technologies were evaluated through life cycle assessment (LCA) and techno-economic analysis (TEA). The experimental results, performed via the LCA and TEA assessments, demonstrated that both solvolysis and pyrolysis are technically, economically, and environmentally viable options for the EoL treatment of biocomposite waste from the aviation industry.

Fabrication of Moth-eye-structured Films with Two Types of Resin Separated by Micro-order Regions

Fabrication of Moth-eye-structured Films with Two Types of Resin Separated by Micro-order Regions

Effect of hard segment chemistry and structure on the self‐healing properties of UV‐curable coatings based on the urethane acrylates with built‐in Diels–Alder adduct

AbstractThe development of new photoreactive resins to obtain smart coatings and enhance the self‐healing (SH) properties of photoreactive resins has attracted great interest in the past few years, and the investigation of the relationship between phase structure and smart properties is necessary. Herein, four types of urethane acrylate resins with built‐in DA structures with different hard segment structures, and a slight change in the length of the polyol soft segment were prepared. The hard segments were made of hexamethylene diisocyanate (HDI) with a linear structure and isophorone diisocyanate (IPDI) with an alicyclic structure, and the soft segments consisted of polyethylene glycols (PEG 400 and PEG 1000, respectively). The obtained resins were used to prepare polymer films that were cured using UV radiation. The coatings obtained in this way were tested for the influence of the polymer chain architecture on the kinetics of photopolymerization, the properties of the cured coatings, as well as the thermal characteristics and thermoreversibility performance of the cured coatings and their SH ability.

Tensile Performance Mechanism for Bamboo Fiber-Reinforced, Palm Oil-Based Resin Bio-Composites Using Finite Element Simulation and Machine Learning.

Plant fiber-reinforced composites have the advantages of environmental friendliness, sustainability, and high specific strength and modulus. They are widely used as low-carbon emission materials in automobiles, construction, and buildings. The prediction of their mechanical performance is critical for material optimal design and application. However, the variation in the physical structure of plant fibers, the randomness of meso-structures, and the multiple material parameters of composites limit the optimal design of the composite mechanical properties. Based on tensile experiments on bamboo fiber-reinforced, palm oil-based resin composites, finite element simulations were carried out and the effect of material parameters on the tensile performances of the composites was investigated. In addition, machine learning methods were used to predict the tensile properties of the composites. The numerical results showed that the resin type, contact interface, fiber volume fraction, and multi-factor coupling significantly influenced the tensile performance of the composites. The results of the machine learning analysis showed that the gradient boosting decision tree method had the best prediction performance for the tensile strength of the composites (R2 was 0.786) based on numerical simulation data from a small sample size. Furthermore, the machine learning analysis demonstrated that the resin performance and fiber volume fraction were critical parameters for the tensile strength of composites. This study provides an insightful understanding and effective route for investigating the tensile performance of complex bio-composites.

INFLUENCES OF DIFFERENT SOLUTIONS ON THE COLOUR STABILITY AND MICROHARDNESS OF CONTEMPORARY LIGHT CURED COMPOSITES: AN IN VITRO STUDY Received 2022-12-09; Accepted 2023-03-18; Published 202

Despite the accumulation of dental plaque, adsorption of colourant pigment from foods and beverages was found to influence the quality of aesthetic restorations. The study aimed to evaluate the influence of different solutions on colour stability and microhardness of microhybrid and nanofilled composite resins. This project was a laboratory based experimental study. Three types of composite resins were used; microhybrid (FiltekTM Z250), nanohybrid (FiltekTM Z250 XT) and universal nanocomposite (FiltekTM 350 XT). A total of 135 disc-shaped specimens were prepared and were randomly divided into five subgroups (n = 9): artificial saliva, mouthwash, carbonated drink, energy drink and coffee. Samples were immersed in the solutions at time intervals of 24 hours, 7 days, 14 days, 21 days and 28 days. All specimens were assessed for the staining effect using a spectrometer (QE65000) and microhardness evaluation using the Vickers indenter (LECO LM 248AT, St. Joseph, Michigan, USA). Data on spectrometer colour spectrum and surface hardness were subjected to a one-way ANOVA and Tukey HSD test at a significance level of P &lt; 0.05. There was a significant difference in discolouration between all three types of composite resins when immersed in all solutions regardless of the pH values (P &lt; 0.05). Vickers hardness test showed statistically significant microhardness among all composite resins on Day 28. The staining medium caused significant discolouration and decreased the hardness of all the materials tested. Microhybrid composite resin reported the lowest colour variations and resistance to hardness test.

Paint and Coatings Market Report by Resin Type

Paint and Coatings Market Report by Resin Type

Stability and Population of Radicals in Electrical Trees in Epoxy Resins Based on Electron Paramagnetic Resonance Spectroscopy

The stability and population of radicals in aged epoxy resins with different electrical trees are investigated by electron paramagnetic resonance. Branch trees and bush trees of various sizes are produced in three types of epoxy resins which are cured by different curing agents. By examining the lifetime of radicals in three epoxies, the mobility of polymer chains is found to act as a vital factor for stability. The recombination of radicals is faster in polymers with higher mobility, leading to a shorter lifetime of radical signals. A distinguishable singlet appears in specimens without visible tree channels, proving that radicals are a precursor of electrical trees. Among spectra from a series of branch trees, two species of radicals are found to be generated successively as tree size increases. By comparing the signal intensity of branch trees and bush trees of similar sizes, bush trees show a much smaller radical population, which is attributed to relatively low electrical stress at branch tips and slow degradation of polymer chains.

Adhesion of veneering composite to metal-free CAD/CAM materials: effect of surface conditioning and adhesive resin type

ObjectivesThis study aimed to investigate the adhesion of veneering composite to metal-free computer-aided design/computer-aided manufacturing (CAD/CAM) materials with different compositions after surface conditioning and application of adhesive resins.Materials and MethodsA total of one hundred and sixty specimens were divided into four groups (n = 40) manufactured either from polyetheretherketone (PEEK; KERAstar PEEK), polyetherketoneketone (PEKK; Pekkton), fiber-reinforced composite (FRC; Trinia), or high-impact polymer composite (COMP; Bredent HIPC) CAD/CAM discs. Each group was then randomly subdivided into four different subgroups of adhesive systems (n = 10) as Visiolink (Bredent), Single Bond Universal (3M), G-Premio BOND (GC), and OptiBond Universal (Kerr). The shear bond strength (SBS) of each specimen with veneering composite material was tested with a universal testing machine following thermocycle aging (5000 times). The modes of failure resulting from the tests were determined with scanning electron microscope (SEM), dispersive spectroscopy (EDS), and analytical imaging. The data were statistically analyzed with two-way ANOVA and Bonferroni post hoc tests (alpha = 0.05).ResultsThe highest SBS values among all groups were found for the COMP material (20.28 ± 2.08 MPa) with OptiBond Universal adhesive, while the lowest for the PEEK material (10.33 ± 2.47 MPa) with G-Premio BOND. The most common failure mode for the PEEK and PEKK specimens was adhesive failure, for the FRC and COMP groups mixed failures were common.ConclusionsBond strength values of at least 10 MPa were achieved for all tested between metal-free CAD/CAM materials and adhesive resin application.