Ceramic Cement Research Articles

Effect of siloxane quantity and ph of silane coupling agents and contact angle of resin bonding agent on bond durability of resin cements to machinable ceramic.

The aim of this study was to measure siloxane quantity, pH value, and resin wettability on ceramics silanized by five silane coupling agents, and to test the correlation of these parameters of silane coupling agents with bond durability between a machinable glass ceramic and resin cements. 1.5-mm-thick ceramic plates (ProCAD, Ivoclar Vivadent) were polished, cleaned, and bonded with ten combinations of five silane coupling agents (Monobond S [Ivoclar Vivadent], Rely X Ceramic Primer [3M], Clearfil Ceramic Primer [Kuraray], GC Ceramic Primer [GC], Porcelain Liner M [Sun Medical]) and two dual-curing resin cements (VariolinkII [VLII, Ivoclar Vivadent], Linkmax HV [LMHV, GC]). Their microshear bond strength was measured after 0, 10,000, and 30,000 thermal cycles. Siloxane quantity, pH value of silane coupling agents and contact angle of Heliobond (Ivoclar Vivadent) to silanized ceramic were measured using a FTIR spectrophotometer, pH-indicator strips, and a contact-angle meter, respectively. Bond strength data were analyzed by three-way ANOVA. For each cement, Pearson's correlation coefficient was calculated to analyze possible correlation between bond strength under different thermocycling conditions and absorbance peak of siloxane, pH value of silane coupling agents, and contact angle of resin to the silanized ceramic surface. The bond strength of ceramic was significantly influenced by the silane coupling agent and thermal cycles, not by resin cement. For both cements, only a negative correlation was found to be significant between the contact angle of resin to silanized ceramic surfaces and bond strength after 30,000 thermal cycles. The better the wettability of resin on different silanized ceramic surfaces could improve their bond durability.

Influence of Surface Nano-roughness of Dental Alumina Ceramic on Bond Strength to Dual-Cure Resin Cements

The goal of this research is to evaluate the effect of sandblasting and silica coating on the nano-roughness and on the microtensile bond strength (MTBS) of glass-infiltrated alumina bonded to different resin cements. Six slabs of In-Ceram Alumina (Vita) were randomly treated according to the following groups: (1) no treatment; (2) sandblasting (125 μm Al2O3-particles); and (3) tribochemical silica-coating (50 μm silanated silica particles). Nano-roughness (Ra) was assessed under an atomic force microscope (AFM). Such surface treatments were also applied to nine In-Ceram Alumina CAD/CAM blocks. Ceramic blocks were duplicated in composite resin, and composite samples were bonded to the conditioned surfaces. Each pre-treatment group was divided into three subgroups depending on the resin cement system: (1) Clearfil Ceramic Primer plus Clearfil Esthetic Cement (CEC, Kuraray); (2) RelyX Unicem (RXU, 3M); and (3) Calibra Silane plus Calibra Resin Cement (CAL, Dentsply). After 24 h, the bonded specimens were cut into 1±0.2 mm2 sticks. The MTBS values (MPa) were obtained using a universal testing machine (crosshead speed: 0.5 mm/min). Failure modes were recorded using a scanning electron microscope (SEM). Nano-roughness and MTBS data were analyzed by ANOVA and Student–Newman–Keuls tests (α =0.05). No significant changes in nano-roughness occurred after conditioning. The MTBS of CEC and RXU were comparable despite the surface treatment. All CAL-sticks debonded prematurely. Ceramic pre-treatments, such as sandblasting or silica coating, do not affect the alumina's surface nano-roughness or bond strength. The MDP monomers dissolved in the CEC Primer and the functional dimethacrylate monomers present in the self-adhesive RXU may be the key to successful bonds to alumina.

Color stability of composite resins used for ceramic veneers cementation

Color stability of composite resins used for ceramic veneers cementation

Effect of carbon addition on the ferroelectric hysteresis properties of lead zirconate–titanate ceramic–cement composites

Piezoelectric composites made from lead zirconate–titanate ceramic and cement have recently been developed as sensors in smart concrete structures due to their compatibility with the host concrete structure. However there is difficulty in poling the composite due to the insulating nature of the cement phase. In this work, carbon powder was used as a conducting phase in the composites at up to 2.0% by volume. The ferroelectric properties of the composites were investigated. For the same electric field, composites with added carbon were found to have higher polarization values. Therefore, this suggests that carbon could be added as a conducting phase to lead zirconate–titanate ceramic–cement composites in order to improve their polarization.

Performance investigation of 1-3 piezoelectric ceramic–cement composite

A 1-3 piezoelectric ceramic–cement composite has been fabricated using sulphoaluminate cement and lead niobium-magnesium zirconate titanate ceramics (P(MN)ZT) as matrix and functional component, respectively. The influences of piezoelectric ceramic volume fraction, aspect ratios of piezoelectric ceramic rods and temperature on the piezoelectric and dielectric properties of the composites were studied. This composite was shown to exhibit an improved electromechanical coupling coefficient with the mechanical quality factor reduced. Furthermore, the acoustic impedance of the composites could also be adjusted to match concrete structures. It has been demonstrated that by adjusting the piezoelectric ceramic volume fraction and shape parameters, the developed composite can be eventually used as sensing element in structural health monitoring.

Fracture Loads of All‐Ceramic Crowns under Wet and Dry Fatigue Conditions

The aim of this study was to test the hypothesis that fracture loads of fatigued dental ceramic crowns are affected by testing environment and luting cement. One hundred and eighty crowns were prepared from bovine teeth using a lathe. Ceramic crowns were prepared from three types of ceramic systems: an alumina-infiltrated ceramic, a lithia-disilicate-based glass ceramic, and a leucite-reinforced ceramic. For each ceramic system, 30 crowns were cemented with a composite resin cement, and the remaining 30 with a resin-modified glass ionomer cement. For each ceramic system and cement, ten specimens were loaded to fracture without fatiguing. A second group (n = 10) was subjected to cyclic fatigue and fracture tested in a dry environment, and a third group (n = 10) was fatigued and fractured in distilled water. The results were statistically analyzed using one-way ANOVA and Tukey HSD test. The fracture loads of ceramic crowns decreased significantly after cyclic fatigue loading (p<or= 0.05); furthermore, fracture loads of crowns fatigued in a wet environment were statistically lower than those in a dry environment (p < 0.05). Crowns luted with a composite resin cement showed statistically greater fracture loads than those luted with a resin-modified glass ionomer cement (p<or= 0.05). Fracture load of the three ceramic systems was found to be influenced by ceramic composition. Moreover, cement and fatigue condition influenced the fracture loads of the crown specimens evaluated in this study.

Initial Clinical Experience with a New Biointegrative Cement for Vertebroplasty in Osteoporotic Vertebral Fractures

Polymethylmethacrylate, as a widely used material for vertebroplasty, has several drawbacks such as heat development and high allergenic potential. In order to avoid these drawbacks ceramic cement materials have been developed. The purpose of this study was to evaluate a new biointegrative material for vertebroplasty in osteoporotic vertebral fractures regarding pain relief, safety aspects and technical feasibility. The injectable bone substitute Cerament(TM) SpineSupport has been developed for vertebroplasty of osteoporotic vertebral fractures. The aim of the product is to provide mechanical stability by cured calcium sulfate dehydrate during a period of several weeks and to act as an osteoconductive support by hydroxyl apatite particles. Inclusion criteria were a stable single vertebral fracture at levels Th5 to L5, verified by CT and MRI, and not older than four weeks, in osteoporotic patients aged 60 years or older. Bipedicular vertebroplasty technique was used. Follow up included CT directly after treatment and after two month and pain assessment (VAS) pre and post procedure after two weeks and one month. Seven patients (age range 62 - 96 years, mean 73.9, five women, two men) were treated at levels T 8 (n=1), T 12 (n=4) and L1 (n=2). The average injected volume was 1.9 ml (range 0.2-4 ml). No material or procedure-related complications were observed. An average height loss of the treated vertebral bodies of 3.6 mm (range 1.5-5.4) was seen two months after treatment as compared to pre-treatment CT. Pain assessment by VAS resulted in an improvement from mean 69 prior treatment to 37 the day post treatment, 42 after two weeks and 30 after one month. Initial results indicate that Cerament(TM) SpineSupport is safe and effective in the treatment of acute osteoporotic vertebral body fractures. Further studies with long-term follow-up are needed to confirm these results and to prove the concept of osteoconduction with hydroxyl apatite particles.

Microtensile Bond Strength of Porcelain Laminate Veneers Bonded to Fluorosed Teeth

The aim of this study was to evaluate the microtensile bond strengths (MTBSs) of porcelain laminate veneers bonded to normal and fluorosed teeth. Forty human incisors, including 20 normal and 20 moderately fluorosed teeth [Thylstrup Fejerskov Index (TFI) = 4 to 6], were collected. The labial surfaces of the teeth were ground up to 1 mm and polished with #600 silicon carbide abrasive paper. The surfaces were bonded to 1-mm-thick ceramic slices (5 x 5 mm(2)) previously made (VitaVM7) using one of two ceramic cement systems (RelyX or Clapearl) following the manufacturers' instructions. A resin composite was added on top of the ceramic slices and built up to 5-mm thickness to serve as grips. The specimens were stored in water (37 degrees C) for 24 hours, and beams of adhesive interface with a surface area of approximately 1.25 mm(2) were obtained. Then the beams were subjected to MTBS tests at a crosshead speed of 1.0 mm/min. The data were analyzed with two-way ANOVA. The results of the MTBS test (MPa) were 20.55 +/- 5.83 (RelyX/fluorosed), 20.16 +/- 4.61 (RelyX/normal), 18.74 +/- 2.88 (Clapearl/fluorosed), and 21.06 +/- 4.99 (Clapearl/normal). There were no significant differences in the MTBSs among the four groups (p > 0.05). The MTBSs of ceramic cement systems used were not influenced by the moderately fluorosed teeth.

Production of construction materials using technogenic wastes

The utilization of technogenic wastes, first and foremost, wastes produced in the mining and reprocessing industries, and precipitates from biological purification of sewage at aeration plants in cities and waste water from works producing large quantities of building materials, such as ceramic bricks and cement, can provide a solution to acute ecological and technical problems in the building materials industry.

Use of some industrial wastes in production of surface thermoisolator tials

processing of non-conducting mosaic( from glass waste , ceramic and white cement ) for roofing which includes coating the building roofs . It is non- conducting for heat , humidity and sound . It functions as a substitute for processed cement coats and tiles which are used in coating building roofs . The most important point is to get rid of environment pollutions cullet glass, ceramic and cement , and re-use them

Dielectric, Piezoelectric, and Elastic Properties of Cement‐Based Piezoelectric Ceramic Composites

The material properties, including piezoelectric, dielectric, and elastic properties of cement‐based piezoelectric ceramic composites are measured in our study. Different kinds of diphase composite models are proposed to explain the material properties. The modified cube model with chemical reaction is adopted because of the chemical reaction existing between lead zirconate titanate (PZT) ceramic particles and cement grains. The experimental results match the model very well. Moreover, the influence of volume fraction of PZT ceramic on the material properties of composites is also discussed in detail. The results show that the material properties of cement‐based piezoelectric ceramic composite can be tuned to a compatible value to match the requirement of structure materials, i.e. concrete.

Effect of nano-silica coating prepared by different concentration silica sol on shear bond strength of alumina ceramic

To evaluate the effect of nano-silica coating prepared by different concentration silica sol on shear bond strength between alumina ceramic and resin cement. Silica coating was prepared with colloidal silica sol on alumina ceramic surface that was treated with air particle abrasion. Infrared spectrum (IR), scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS) were used to analyze the silica coating. A total of 32 alumina ceramic discs were randomly divided into 4 groups with 8 discs per group, which received different surface treatments as silane couple agent (control group), 20% silica sol + silane (group A), 30% silica sol + silane (group B), 40% silica sol + silane (group C). Each ceramic disc was bonded to composite with resin cement, and then shear bond strength of these samples was tested. It was observed from the IR pictures that symmetrically flexible vibration absorption kurtosis, anti-symmetrically flexible vibration absorption kurtosis, and bending vibration absorption kurtosis of Si-O-Si enhanced after heat treatment. SEM pictures showed that nanoparticles in coating gel were well distributed and some of them conglomerated after heat treatment. There was a little conglomeration in 20% coating, more in 30%, and the most in 40%. Contents of surface silicon increased after modification with silica coating prepared by sol-gel method. Bond strength of three groups with silica coating was significantly higher than that of the group with only silane couple agent [(1.881 +/- 0.156) MPa] (P < 0.05). Group B gained the highest strength [(4.852 +/- 0.178) MPa] compared with group A [(3.196 +/- 0.171) MPa] and group C [(3.576 +/- 0.671) MPa] (P < 0.05). Surface silicon contents all increased after surface modification with different concentration silica sol. Silica coating followed with silane couple agent could significantly enforce bond strength of alumina ceramic, with 30% silica sol group gaining the highest bond strength.

High temperature sensing using higher-order-mode rejected sapphire fiber gratings

In this paper, we report the fabrication of higher-order-mode rejected fiber Bragg gratings (FBGs) in sapphire crystal fiber using infrared (IR) femtosecond laser illumination. The grating is tested in high temperature furnace up to 1600 degree Celsius. As sapphire fiber is only available as highly multimode fiber, a scheme to filter out higher order modes in favor for the fundamental mode is theoretically evaluated and experimentally demonstrated. The approach is to use an ultra thin sapphire crystal fiber (60 micron in diameter) to decrease the number of modes. The small diameter fiber also enables bending the fiber to certain radius which is carefully chosen to provide low loss for the fundamental mode LP01 and high loss for the other high-order modes. After bending, less-than-2-nm resonant peak bandwidth is achieved. The grating spectrum is improved, and higher resolution sensing measurement can be achieved. This mode filtering method is very easy to implement. Furthermore, the sapphire fiber is sealed with hi-purity alumina ceramic cement inside a flexible high temperature titanium tube, and the highly flexible titanium tube offers a robust packaging to sapphire fiber. Our high temperature sapphire grating sensor is very promising in extremely high temperature sensing application.

ADHESIVE CEMENTATION OF HIGH‐STRENGTH CERAMICS

ADHESIVE CEMENTATION OF HIGH‐STRENGTH CERAMICS

Strength estimation of different designs of ceramic inlays and onlays in molars based on the Tsai-Wu failure criterion

Successful restoration of large molar defects is a serious clinical problem. Studies on the strength of teeth restored with ceramic restorations of various designs have provided conflicting results. The purpose of this study was to determine the shapes of large MOD ceramic restorations in molars most likely to prevent failure and to produce a favorable distribution of contact stresses between the cement and teeth during mastication. The study was performed using a finite element analysis with contact elements. Eight 2-dimensional models of mandibular first molars with the following designs of MOD ceramic restorations were created: an inlay with a butt joint margin, an inlay with a beveled margin, an onlay with a butt joint margin, and an onlay with a rounded shoulder margin. The restorations had 3-mm or 5-mm isthmus widths. Models of opposing maxillary crowns were also developed. Computational simulation of mastication of boluses in the frontal plane was conducted, during which the stresses occurring in the ceramic restorations, cement, and tooth structure were calculated. The Tsai-Wu failure criterion was used to evaluate the strength of the materials. Contact stresses at the adhesive interface between the tooth structure and resin cement around these restorations were analyzed. According to the Tsai-Wu failure criterion, the margin of the beveled inlay and the surrounding tissue could be damaged during masticatory simulation. At the junction of the butt joint margin inlay and enamel, contact tensile stresses appeared. The lowest inverse of the Tsai-Wu strength ratio index appeared in the onlay with a rounded shoulder margin. At the adhesive interfaces around margins of large onlays, compressive contact stresses occurred. For the large molar MOD ceramic restorations tested, the lowest values of the inverse of the Tsai-Wu strength ratio index and a favorable distribution of contact stresses between restoration and tissues appeared in the onlay with a rounded shoulder margin.

Contemporary All-ceramic Systems – Part 2

Current all-ceramic materials offer a accepted level of fracture resistance, fit and aesthetics. High fracture resistance recommends it to be a material to support fixed partial denture (FPD) in a stress bearing area with clinical success. This part of the present literature review covers the success rate, selection criteria of all ceramic systems, cementation technique, finishing and polishing. In vitro and in vivo studies of new high strength ceramics were well documented. Data suggest that single crowns in the anterior and posterior region are more predictable than bridges. Well-studied long-term success rate for FPDs are very limited.

In Vitro Bioactivity of Injectable Ceramic Orthopaedic Cements

The objective of this paper is to investigate and compare the in vitro bioactivity of three injectable cements for orthopaedic applications. The cements were all based on chemically bonded ceramics technology; calcium phosphate (Norian SRS), and experimental versions of calcium silicate and calcium aluminate cements. The cements were mixed with their respective liquids and were after setting stored in phosphate buffered saline at 37 °C for time periods of 1h, 24 h, 7 days and 30 days. After storage the samples were analysed with scanning electron microscopy (SEM), thin film X-Ray diffraction (TF-XRD) and energy dispersive spectroscopy (EDS) for the presence of possible apatite on the sample surface. The SEM and EDX analyses showed that surface films containing Ca and P (along with the other atoms present in the materials) were formed on all materials. Thus reactions with the storage medium had occurred. The TF-XRD analysis confirmed the presence of apatite for the calcium phosphate cement and the calcium aluminate cement. On the calcium silicate cement most of the surface zone seemed to be amorphous with only broad peaks corresponding to apatite. Thus all the tested materials showed signs of in vitro bioactivity.

Progress on adhesion behavior between composite resin cement and ceramics

全瓷修复体以多种优良的特性赢得了医师和患者的青睐,其临床应用的成败很大程度上取决于陶瓷与树脂黏结剂的黏结强度.论述了黏结的重要性并围绕陶瓷的表面处理技术及材料的性质对黏结强度的影响等问题综述了陶瓷-树脂黏结剂黏结的最新进展。

Intra‐articular calcium phosphate cement: Its fate and impact on joint tissues in a rabbit model

Clinical application of injectable ceramic cement in comminuted fractures revealed penetration of the viscous paste into the joint space. Not much is known on the fate of this cement and its influence on articular tissues. The purpose of this experimental study was to assess these unknown alterations of joint tissues after intra-articular injection of cement in a rabbit knee. Observation periods were from 1 week up to 24 months, with three rabbits per group. Norian SRS cement was injected into one knee joint, the contralateral side receiving the same volume of Ringers' solution. Light microscopic evaluation of histologic sections was performed, investigating the appearance of the cement, inflammatory reactions, and degenerative changes of the articular surface. No signs of pronounced acute or chronic inflammation were visible. The injected cement was mainly found as a single particle, anterior to the cruciate ligaments. It became surrounded by synovial tissues within 4 weeks and showed signs of superficial resorption. In some specimens, bone formation was seen around the cement. Degeneration of the articular surface showed no differences between experimental and control side, and no changes over time became apparent. No major degenerative changes were induced by the injected cement. The prolonged presence of cement still seems to make it advisable to remove radiologically visible amounts from the joint space.

A fast-response thin film thermocouple to measure rapid surface temperature changes

A thin film thermocouple has been developed to measure rapid surface temperature change. A fine wire of Constantan was inserted vertically into a hole drilled through a steel plate and held in place by ceramic cement that acted as an electrical insulator. A thin conductive film was deposited on the surface to provide an electrical connection between the steel substrate and the thermoelectric wire. The voltage difference between this junction and a second junction kept in an ice bath was calibrated as a function of the surface temperature. Tests showed that the thin film sensors could detect a temperature rise of over 200 °C in less than 10 ns produced by a laser pulse focused on the junction. The sensors were also used to measure transient surface temperature distribution under an impacting droplet of molten aluminum.