Type Of Surface Treatment Research Articles

Effect of Remineralizing Agents and Resin Infiltration on Resistance to Demineralization of Artificial Enamel Lesions

objective: The purpose of this study was to evaluate the effect of different remineralizing agents and resin infiltration on resistance to demineralization of artificial enamel lesions using a pH cycling model. Materials and Methods: A total of 63 anterior bovine teeth were randomly assigned to nine groups (n=7). Artificial white spot lesions were created on the labial enamel surface using the demineralizing solution for all groups except for sound enamel group. Different surface treatments were then performed; G1: Artificial saliva, G2: Clinpro White Varnish™, G3: Tooth Mousse®, G4: MI Paste Plus®, G5: Artificial saliva/ ICON®, G6: Clinpro White Varnish™/ICON®, G7: Tooth Mousse®/ ICON®, G8: MI Paste Plus®/ ICON®, G9: sound enamel. All treated artificial enamel lesions were subjected to pH cycling. The whole nine groups were then submitted to cross-sectional microhardness using Vicker’s microhardness test, each specimen was measured at five predetermined depths. ANOVA was used to analyze the data. Results: Two-Way ANOVA revealed that the type of surface treatment had a significant effect. Meanwhile, depth of measurement had no significant effect on cross-sectional microhardness of artificial enamel lesions. Conclusion: Remineralizing agents are effective in resisting demineralization in treated artificial enamel lesions and their effect is not potentiated by ICON® treatment. Clinical significance: One-month daily application of MI Paste Plus® was efficient to restore and maintain microhardness of enamel.

Effect of Surface Treatment on Mechanical Properties of Rice Husk Reinforced Recycled High Density Polyethylene (rHDPE) Composites

The aim of this work was to investigate the effect of surface treatment on rice husk reinforced recycled high density polyethylene (rHDPE) composites. Three types of surface treatment on rice husk were carried out which were maleated treatment, alkaline treatment and acrylic acid treatment. The characteristics and mechanical properties of the composites were analysed. The results for all treatments showed that tensile strength and break elongation of composites decreased significantly when the rice husk filler loading increased. Further findings showed that maleated treatment on rice husk can further enhance the mechanical properties due to the present of ester bond formed in FTIR analysis.

Influence of Mercerization Process on the Surface of Coconut Fiber for Composite Reinforcement

The high consumption of green coconut water, especially in tropical countries like Brazil, generates an aggravating factor to the environment, which is associated with the waste generated after its consumption. Thus, one of the possible ways of reusing the coconut shell after consumption is through the extraction of its fibers, which are considered for several applications. In general, natural lignocellulosic fibers (NLFs) have been used for many purposes, such as reinforcement filler in composite materials, since they have low cost and good mechanical properties. With the intention of providing a better compatibility between the NLFs and the composite polymeric matrix, different types of surface treatments are carried out on the fibers, including mercerization, a chemical treatment in which a basic solution is used. In this sense, the present work aims to verify the influence of mercerization with 3% sodium hydroxide (NaOH) on coconut fiber. Among the analyses carried out, stands the scanning electron microscope (SEM) on fresh and treated coconut fibers. The SEM analyses, allowed to observe that after treatment via mercerization, the fibers displayed a greater surface roughness. This indicates the partial removal of lignin, hemicellulose and some other extracts present on the outer layer of the coconut fiber. Therefore, mercerization will probably enable a better mechanical anchoring between fiber and matrix. Results obtained suggest the effectiveness of the mercerization process. However, it was also of concern that such treatment tends to generate NaOH residues, which is a negative factor regarding sustainability.

Airborne-particle Abrasion and Dentin Bonding: Systematic Review and Meta-analysis.

The literature reviewed suggests that airborne particle abrasion has no negative effects on the bond strength of resin-based materials to dentin and that a positive influence on dentin bond strength was only achieved in specific air-abrasion conditions. In this systematic review the authors investigated how airborne-particle abrasion (APA) using aluminum oxide affects the bond strength of resin-based materials to dentin. The search was performed in three databases. In vitro studies (Type of study) comparing the bond strength of resin-based materials (Outcome) to air-abraded (Intervention) compared with non-air-abraded (Comparison) human dentin (Population) were included (the PICOT elements are given parenthetically). From 5437 unique articles, 65 were read in full, 33 were included in the qualitative synthesis, and 32 were included in the meta-analysis. Methodologic quality and risk of bias were assessed. Comparisons were performed between air-abraded and control dentin groups by adopting a random-effects model (α=0.05). Additional analyses were carried out for the different parameters used in APA: type of surface treatment in the control group, particle size, air pressure, and APA duration. The bond strength to air-abraded dentin was favored only when the control surface was treated with a hand excavator. For particle size, APA was favored when the particle size was >30 μm and the controls were no treatment or hand excavator or when the particle size was ≤30 μm and the control was bur. In addition, the results favored air-abraded groups only when the pressure was > 5 bar and bur was used in the control group. No significant differences were observed for duration of APA. No comparison on bond strength considering the presence of aging conditions was possible in the included studies due to the low number of studies that aged the specimens. In conclusion, APA had no negative effects on the bond strength of resin-based materials to dentin and was able to improve the dentin bond strength only when the particle size was > 30 μm and air pressure was > 5 bar. PROSPERO registration protocol: CRD42018096128.

Influence of Various Chemical Surface Treatments, Repair Materials, and Techniques on Transverse Strength of Thermoplastic Nylon Denture Base.

The process of repairing the fractured nylon denture bases and addition of acrylic teeth to the previously worn nylon denture bases has not been widely studied. This study aims to assess the transverse strength of nylon denture bases repaired by various resin materials, different curing techniques, and types of surface treatments. Materials and Methods. One hundred fifty thermoplastic nylon denture base samples were fabricated using plastic patterns measuring 65 × 10 × 2.5 mm (length, width, and thickness, respectively). These samples were then divided into three equal groups. Fifty samples were repaired by microwave heat-polymerization, fifty samples were repaired using the Ivomate autopolymerization, and the other fifty were repaired using light-polymerized acrylic resin. Each of these three groups was further divided into five subgroups of ten samples based on the type of surface treatment. The samples in the control group did not undergo any surface treatment, and the other four groups were chemically surface treated with monomer, acetone, ethyl acetate, and isopropanol, respectively. A three-point bending test was used to calculate the transverse strength values of the samples. Fourier transform infrared (FTIR) analysis was conducted to determine the component of functional groups between the polyamide nylon base and poly(methyl-methacrylate) PMMA repair materials. A polarizing microscope was utilized to investigate the mode of failure at the fracture surfaces. Results. The collected data were analyzed with one-way ANOVA and Sidak's multiple comparison test to show the differences among different groups. For surface treatments, the highest transverse strength values were obtained by monomer-treated samples (18.29 N/mm2); however, the lowest values were obtained in non-surface treated samples (5.58 N/mm2). While for repair techniques, the highest transverse strength values were obtained by microwave processing, followed by Ivomate and then the light-cured polymerization. The means were found to be significant (p < 0.001). FTIR analysis shows the presence of hydrogen bonding which is due to the ester and amid groups which enhance the bond strength of the surface-treated samples. The interface of the polarizing microscope images revealed a cohesive fracture within repair materials rather than the adhesive nature. Conclusion. The microwave-polymerized resin was considered as the most effective repair technique along with monomer chemical etchant which creates a tight adhesion between PMMA and nylon denture base in comparison to other groups.

Stress Corrosion Resistance of Laser Shock Peening/Microarc Oxidation Reconstruction Layer Fabricated on AZ80 Magnesium Alloy in Simulated Body Fluid

Three types of surface treatments were performed on AZ80 magnesium (Mg) alloy by laser shock peening (LSP), microarc oxidation (MAO), and laser shock peening followed by microarc oxidation (LSP/MAO). The stress corrosion resistance of treated and untreated specimens was carried out using slow strain rate tensile testing at a strain rate of 5 × 10−7/s in simulated body fluid. The influence of microstructure on the stress corrosion behavior was analyzed by x-ray diffraction, transmission electron microscopy, scanning electron microscopy, and electrochemical measurement. The results showed that the LSP/MAO specimen has a higher stress corrosion resistance compared to the AZ80 Mg alloy substrate, the LSP-treated specimen, and the MAO-treated specimen. The factors improving the stress corrosion resistance of the LSP/MAO specimen are its nanocrystalline material, compressive residual stress, and favorable (0002) basal texture of its reconstructed layer.

Effect of cold plasma spray on microshear bond strength of repair composite resin in comparison with other surface treatments

Following composite restorations, there is an obvious need for repair of them, which can be a challenging procedure in the clinical setting. This study aimed to assess the effect of surface treatment of composite with cold plasma spray (CPS) on microshear bond strength (µSBS) of repair composite in comparison with other surface treatments. A total of 120 discs (2 × 9 mm) were fabricated of Filtek Z250 composite. After aging by 5000 thermal cycles (5–55 °C), the samples were randomly divided into 4 groups (n = 30) for surface treatment by bur, Er,Cr:YSGG laser irradiation, sandblasting and CPS. After etching and application of Scotchbond Universal, Filtek Z250 repair composite was applied into Tygon tubes and bonded to the prepared surface. Half of the samples in each group (n = 15) were immersed in distilled water and incubated at 37 °C for 24 h. The other half was thermocycled. All samples then underwent µSBS test in a universal testing machine with a crosshead speed of 1 mm/min. The mode of failure was determined under a stereomicroscope. Data were analyzed by two-way ANOVA (p = .05). Aging (p = .13) and type of surface treatment (p = .44) had no significant effect on µSBS of repair composite. All failures were adhesive. Different surface treatments and aging process had no significant effect on µSBS of repair composite. However, application of CPS slightly increased the µSBS of repair composite after aging.

The Effect of Finishing and Polishing Sequences on The Surface Roughness of Three Different Nanocomposites and Composite/Enamel and Composite/Cementum Interfaces

The purpose of this study was to investigate the effect of final surface treatment and dental composite type on the roughness of the composite surface, composite/enamel interface, and composite/cementum interface, as well as on the polishing time. Class V cavities prepared in extracted teeth (n = 126) were restored using one of the three nanohybrid composites with different filler sizes. The specimens were randomly assigned to three different finishing and polishing sequences. The roughness (Ra) of the investigated surfaces was measured using the contact profilometer. The time required to achieve visible gloss was documented. The data were analyzed using ANOVA with Tukey’s post hoc test (p < 0.05). There was no significant influence of the composite type on the restoration surface roughness (p = 0.088), while the polishing method had a significant impact (p < 0.001). The Ra of the composites ranged between 0.08 µm and 0.29 µm, with the lowest values (0.09 µm ± 0.05 µm) found in the aluminum oxide disc group (p < 0.001). The time to achieve a visible composite gloss was influenced by the polishing method, composite type, and interactions between these factors (p < 0.001). The interface roughness was significantly greater than that of the composite surface (p < 0.001), and depended on the composite type and polishing system employed.

Shear bond strength of cemented zirconia-reinforced lithium silicate ceramics (Celtra Duo) with two surface treatments (in vitro study)

Enhance the bonding of cement to ceramic surface with a variety of ceramic surface modifications have been established. Air-abrasion using alumina particles, hydrofluoric acid has been shown to provide micromechanical interlocking at the ceramic-resin interface. The aim of the present study was to evaluate the effect of two surface treatments; acid etching and sandblasting; on the shear bond strength of cemented newly introduced zirconia-reinforced lithium silicate ceramics following thermocycling. Methods: 24 discs of Zirconia- reinforced glass ceramics (Celtra Duo) were tested using 10% hydrofluoric acid for 20 s (control group) and 50 µm aluminum oxide for 60 s at 10 mm distance from the nozzle tip of sandblasting machine. Subsequent to the surface treatments, both groups were salinized and cemented to composites background discs using self-adhesive dual cure resin cement (BisCem). All sample were subjected to 2500 thermal cycle shear bond strength and failure mode was evaluated. The results of the t-test indicated that the bond strength value is significantly influenced by the surface treatment method. It was found that hydrofluoric acid group recorded statistically significantly higher shear bond strength mean value (10.81 MPa) than aluminum oxide sandblasting group (7.76 MPa) as indicated by t-test (t = 2.9, p = 0.0109 < 0.05). Conclusion: failure mode showed a relation between the bond strength and the failure type mixed failure showed with higher bond valves and cohesive failure accompanied with lowest bond strengthen values. The shear bond strength of zirconia reinforced lithium silicate (Celtra Duo) ceramic cemented to resin cement was affected by the type of surface treatment.

Influence of surface treatments in natural fibre reinforced composites

There have been numerous endeavors to replace synthetic fibers with natural fibers in fiber reinforced composites, due to increasing environmental alertness and diminution of oil assets. The information that natural fibers are existing inexpensively and in plenty, being biodegradable and low density, have driven many scientists throughout the world to reconnoiter their application potential in several industrial segments. Nevertheless, natural fibers also require some confines such as high moisture absorption and subsequent swelling and degradation, poor chemical and fire resistance, high dispersion of mechanical properties, poor interfacial interactions with polymeric matrices. Consequently, there is an enormous concern to modify the surface of natural fibers through many techniques, in order to overcome their intrinsic downsides and to effectively utilize these materials in different applications. The chemical treatment of fiber is intended at improving the adhesion between the fiber surface and the matrix. Modification in fiber surface results with increase in fiber strength. This study compares the result of different types of surface treatments of natural fibrous materials, chiefly Calotropis procera and Sisal fibers, on the mechanical properties of fiber composites. The application of surface treatments on fibrous materials can improve the compatibility with composite materials.

The Effects of 2 Types of Cements and 2 Types of Surface Treatments on Shear Bond Strength of Zirconia

Aim: The aim of this study is to evaluate the interactive influence of different types of cement and surface treatments on bond strength of zirconia. Materials and Methods: Thirty cylindrical zirconia blocks (Diameter4mm& thickness4mm)were fabricated for the study. All the specimens were ground with 600 grit silicone carbide polishing paper. Zirconia specimens were randomly divided into three main groups. 1stcontrol (600grit) no surface treatment. 2ed the specimens were air-abrasion with 50um aluminum oxide particles (Al2O3). 3 rd the specimens were air-abrasion with 50um aluminum oxide particles (Al2O3)+ silane .Then ,each group was divided into two groups according to the luting cement used which are( Reinforcd glass ionomer cement and dual cure resin cement).The zirconia blocks bonded to the composite blocks using these types of cements. Then each pair of zirconia block and composite was applied to load of( 15 Kg) for 15 minutes in order to standardized the applied pressure for each type of cement . The resin cement was then light polymerized for 30s with LED light at 500mW/cm2 (Ledition, Ivoclar Vivadent, Liechtenstien) at the distance of 1mm from each direction. The specimens were stored for 24 hours at 37℃. Shear bond strength was measured by using Universal Testing Machine, and mode of failure examined by a stereomicroscope. Results: All the zirconia blocks were bonded to the composite blocks by self adhesive resin cement revealed results more preferable than zirconia blocks were bonded to the composite blocks by Reinforced glass ionomer cement. The shear bond strength between Zirconia and self-adhesive resin cement for the surface were treated with Aluminum-oxide air abraded alone, and zirconia surface were treated with Aluminum-oxide air abraded + silane more preferable than shear bond strength cement between Zirconia and Rinforeced glass ionomer cement for the surface were treated with Aluminum-oxide air abraded alone, and zirconia surface were treated with Aluminum-oxide air abraded + silane. Conclusion: Zirconia was more durable with Self-adhesive resin cement than Reinforced glass ionomer cement. Zirconia Surface treatments were very critical for improvement bond strength with cement in addition to the properties of that cement .

The effect of surface treatment and environmental actions on the adhesive connection between GFRP laminate surface and fresh FRC

An experimental study on the performance of adhesive connection between Glass Fibre Reinforced Polymer (GFRP) plates and Steel Fibre reinforced self-compacting Concrete (FRC) was conducted. Fresh FRC was poured out onto the surface of GFPR plates, to create 40 square specimens (300 by 300 by 45 [mm]). Pull-off tests were performed to evaluate the tensile strength of the adhesive connection when different types of adhesives (four) and surface treatments (three) are used. Furthermore, the effect of five different environmental conditions on the tensile strength of the adhesive connection was also evaluated. After analysing the results and performing a variance analysis (ANOVA), it has been shown that the pull-off behaviour is highly influenced by the type of adhesive and by the environmental action. In spite of that, the dominant failure mode was cohesive failure in the FRC substrate, therefore good bond conditions between both materials were achieved.

Microshear bond strength of contemporary self-adhesive resin cements to CAD/CAM restorative materials: effect of surface treatment and aging

The objective of this in vitro study was to investigate the effect of material type, resin cement type, surface treatment, and aging on the microshear bond strength (µSBS) of self-adhesive resin cements (SARCs) to CAD/CAM blocks. CAD/CAM blocks (CeraSmart, CS; Lava Ultimate, LU; Shofu Block HC, HC; Vita Enamic, VE; Vitablocks Mark II, VM) were cut into 3-mm thick slices (96 specimens for each) and divided into groups: no treatment; 9% hydrofluoric acid etching; aluminum-oxide sandblasting; CoJet sandblasting. Following, the specimens were divided into three subgroups according to SARCs applied. Each specimen received four resin cement microtubules (n = 32 per subgroup). After 24 h, the cylinders of SARC were equally assigned into two groups (n = 16): immediate µSBS testing and µSBS testing after thermocycling. A shear force was applied to the adhesive interface through a μSBS testing device. Additionally, specimens were analyzed with a contact profilometer and were evaluated with scanning electron microscopy. The data were analyzed using four-way ANOVA, p < 0.05. Material type, resin cement type, surface treatment, and aging influenced the µSBS values (p < 0.001). A significant decrease in µSBS was recorded for all groups after thermocycling. The most common failure mode was detected as an adhesive failure. The surface treatment and material type influenced the surface roughness with a significant interaction. Sandblasting was more successful for CS, LU, and HC, while HF etching was better for VE and VM. The use of MDP-containing SARCs would be advantageous for the zirconia-containing CAD/CAM materials (LU and HC).

Influence of the molding process and different surface regularization methods on the compressive strength of concrete specimens

Concrete is one of the most important material for civil construction, given its high applicability. C Compressive strength (fc) is one of the main parameters to evaluate the concrete quality. Concrete of the same mixing volume may vary even with the same materials preparation. Concrete specimens molding, and its surface regularization contribute to these variations that are often hard to measure. Therefore, this paper aims to determine the variations in compressive strength of concrete, simulating different processes for casting, initial curing and surface treatment. In stage 1, the specimens were subjected to five surface treatment types, resulting in variations of 30% for concrete fc, whereas grinding specimens reached the highest 28-day compressive strength, so they were carried over to the next stage. In stage 2, specimens were produced as per ABNT NBR 5738 (2015) and with induced errors in casting and initial curing. The specimen produced according to the standard achieved the second-best result, whose 28-day fc was3% lower than that of the similar method, despite leaving the specimen uncovered for the first 24 hours after casting. Specimens produced in metal cylinder form works shows higher results than those produced in polyvinyl chloride molds (PVC).

Grinding of composite cores using diamond burs with different grit sizes

Aim: To evaluate the retention of Y-TZP crowns cemented in aged composite cores ground with burs of different grit sizes. Methods: Sixty composite resin simplified full-crown preparations were scanned, while 60 Y-TZP crowns with occlusal retentions were milled. The composite preparations were stored for 120 days (wet environment-37°C) and randomly distributed into three groups (n=20) according to the type of composite core surface treatment. The groups were defined as: CTRL (control: No treatment), EFB (extra-fine diamond bur [25μm]), and CB (coarse diamond bur [107μm]). The grinding was performed with an adapted surveyor standardizing the speed and pressure of the grinding. The intaglio surfaces on the crowns were air-abraded with silica-coated alumina particles (30 μm) and then a silane was applied. The crowns were cemented with self-adhesive resin cement, thermocycled (12,000 cycles; 5/55°C), stored (120 days) and submitted to aretention test (0.5mm/min). The retentive strength data (MPa) were analyzed using one-way analysis of variance and Tukey test, as well as Weibull analysis. Failures were classified as 50C (above 50% of cement in the crown), 50S (above 50% of cement in the substrate) and COE (composite core cohesive failure). Results: No statistical difference was observed among the retention values (p=0.975). However, a higher Weibull modulus was observed in the CTRL group. The predominant type of failure was 50S (above 50% of cement in the substrate composite). Conclusion: The retention of zirconia crowns was not affected by grinding using diamond burs with different grit sizes (coarse/extra-fine) or when no grinding was performed.

The Effect of Different Combinations of Surface Treatments and Bonding Agents on the Shear Bond Strength Between Titanium Alloy and Lithium Disilicate Glass-Ceramic

In order to obtain a more-natural esthetic prothesis, the use of hybrid abutments is becoming widespread in implant dentistry. The aim of this in vitro study was to assess the effects of different surface treatments, as well as the effects of different combinations of surface treatments and cementation protocols, on the shear bond strength between titanium alloy disks and lithium disilicate glass-ceramics. Forty titanium-alloy disks (4 × 6.6 mm) were fabricated using computer-aided designed/computer-assisted manufacturing, and an identical number of lithium disilicate glass-ceramic disks of similar sizes were fabricated by a heat-pressing technique to be attached to the titanium disks. The specimens from each material group were divided into two groups (n = 20 each) according to the surface treatment type: alumina airborne-particle abrasion or etching with hydrofluoric acid. Each group was then divided into two subgroups (n = 10) depending on the resin-cement type: Multilink Hybrid Abutment Cement (Ivoclar Vivadent) or PANAVIA SA Cement Plus (Kuraray). After thermocycling (5,000 cycles), a shear bond strength (SBS) test was conducted using a universal testing machine. Statistical analysis was performed by analysis of one-way analysis of variance and unpaired tests (P < .05). Statistically, the highest SBS values were obtained using airborne-particle abrasion. The surface treatment of titanium alloys by sandblasting led to a higher SBS compared to etching with hydrofluoric acid. The cement type also had a significant influence on SBS results.

Effect of Various Surface Treatments on Ti-Base Coping Retention.

Mechanical surface roughening of the titanium-abutment base is necessary to increase the pull-off bond strength of the lithium disilicate abutment material. Additional chemical surface treatment may further increase the bond strength, but the effects are product specific.

Slip factor of high strength steel with inorganic zinc-rich coating

Abstract The loading resistance of slip critical steel connection is determined by the slip factor between faying surfaces and pretension force in bolts. The shot-blasting treatment is a commonly used and simple type of surface treatments. In order to avoid the risk of rusting of shot-blasted surfaces which threatens the structure safety, shot-blasted surfaces are generally coated with aluminum or zinc-based product. In this study, the slip factors of high strength steels (Q550, Q690 and Q890) with inorganic zinc-rich coating are investigated. Two values of coating thickness (60 μ m and 80 μ m ) are selected and the influence of thickness of coating on slip factor is studied. Based on classical friction mechanism theory, compared with slip factor of shot-blasted surface, the decreasing of slip factor of surface with inorganic zinc-rich coating is analyzed. Moreover, the coating thickness effect on slip factor is also investigated. Because the difference between the measured slip displacement at 5 min (short-term tests) and 3 h (long-term tests) exceed 2 μ m , corresponding creep tests are carried out to evaluate long-term effects. Based on tests results, the recommended values of slip factor of high strength steel surface with inorganic zinc-rich coating is 0.30.

Research of Tribological Properties of 34CrNiMo6 Steel in the Production of a Newly Designed Self-Equalizing Thrust Bearing

There are many cases when in large power equipment (such as a turbine or compressor) asymmetrically loading on bearings due to thermal deformations, production inaccuracies, or simple deflection of the shaft occurs. This asymmetrically loading means misalignment of rotor against stator in angle more than several tenths of a degree and it has an influence on a journal and thrust bearings. Over the last few years, thanks to increasingly precise manufacturing, solutions that can eliminate this phenomenon have been revealed. In the case of the thrust bearing, it is a system of very precise manufactured levers, which are in close contact each to other, so they have to be not only properly designed from the geometrical point of view but the important role plays a quality of the functional surfaces of these levers. The article deals with the surface treatment effect on tribological properties of 34CrNiMo6 steel used for the production of bearing levers, which are the critical parts of a newly developing self-equalizing thrust bearing. The samples with cylindrical and plate shapes were produced from 34CrNiMo6 steel as representatives of the most suitable geometries for contact surfaces. All samples were heat-treated. The surfaces of some samples were treated by electroless nickel plating or nitriding, some of the samples were treated by tumbling. Gradually, the surface roughness, microhardness, metallographic analysis and the influence of selected types of surface treatments on the wear for individual samples were evaluated within the research presented in the article. As the testing methods for evaluation of tribological properties were selected Pin-on-disc test and frequency tribological test. The results showed that the best tribological properties achieved samples treated by electroless nickel plating compared with the nitrided or only heat-treated samples.

Effect of ceramic material type on the fracture load of inlay-retained and full-coverage fixed dental prostheses

Objective Ceramic inlay-retained fixed partial denture (IRFPD) is a conservative prosthetic option but the mechanical durability of new high strength zirconia reinforced glass ceramic FPDs is not investigated. The purpose of this study was to compare fracture load of 3-unit ceramic FPDs. Materials and methods Extracted premolars and molars (N = 64) were used to create three test groups (IRFPDs) and one control group (full coverage FPD) (n = 8). The teeth were embedded in PMMA resin with a mesiodistal distance of 6 mm. Premolars had a distal and molars had a mesial inlay preparation (width: 3 mm; height: 4 mm) in the test groups. IRFPDs were made from a zirconia reinforced lithium silicate (VS) or a monolithic zirconia. Zirconia IRFPDs received 2 types of surface treatments: sandblasting (Zr-IRFPD) or internal coating with feldspathic porcelain (ZrC-IRFPD). Control group was made from monolithic zirconia with the same connector size and zirconia surfaces were sandblasted (Zr-FPD). All restorations were cemented using a resin luting cement. After 5000 thermo-cycles, fracture load values (N) were determined with a universal testing machine at a crosshead speed of 0.75 mm/min. Data were analyzed using 1-way ANOVA and Tukey`s post hoc test (p ˂ .05). Result Fracture load (mean ± SD) of Zr-FPDs, Zr-IRFPDs and ZrC-IRFPDs were 672 ± 183, 672 ± 123 and 638 ± 59, respectively, being not statistically different (p > .05). VS-IRFPD exhibited statically lower values (391 ± 136). The predominant mode of failure was fracture at the connector area in all groups. Conclusion The fracture load of 3-unit IRFPD was significantly affected by types of ceramics but the retainer design and surface treatment in Zr groups did not show a significant effect.