Statement of Problem: In a previous study it was reported that a durable resin-ceramic tensile bond could be obtained by an appropriate silane application without the need for HF acid etching the ceramic surface. Evaluation of the appropriate application of silane by other test methods seems to be necessary.Purpose: The purpose of this study was to compare the interfacial FRACTURE toughness of smooth and roughened ceramic SURFACES bonded with a luting resin.Materials and Methods: Ceramic discs of 10 mm in diameter and 2 mm in thickness were prepared.Four different surface preparations (n=10) were carried out consisting of (1) ceramic surface polished to a 1µm finish, (2) gritblasted with 50µm alumina, (3) etched with 10% HF for 2 min, and (4) gritblasted and etched. The ceramic discs were then embedded in PMMA resin. For the adhesive area, the discs were masked with Teflon tapes. A circular hole with diameter of 3 mm and chevron-shaped with a 90° angle was punched into a piece of Teflon tape. The exposed ceramic SURFACES were treated by an optimised silane treatment followed by an unfilled resin and then a luting resin cylinder of 4mm in diameter and 11 mm in length was built. Specimens were stored in two different storage conditions: (A): Distilled water at 37°C for 24 hours and (B): Distilled water at 37°C for 30 days. The interfacial FRACTURE toughness (GIC) was measured at a cross-head speed of 1 mm/min. The mode of failure was examined under a stereo-zoom microscope and FRACTURE SURFACES were examined under Scanning Electron Microscope.Results: The mean interfacial FRACTURE toughness values were; Group A: 1) 317.1±114.8, 2) 304.5±109.2, 3) 364.5±169.8, and 4) 379.4±127.8 J/m2±SD. Group B: 1) 255.6±134.4, 2) 648.0±185.1, 3) 629.3±182.6 and 4) 639.9 ±489.0 J/m2±SD. One way Analysis of Variance showed that there was no statistically significant difference in the mean interfacial FRACTURE toughness for groups A1-A4 (P>0.05). However, the mean interfacial FRACTURE toughness for group B1 was significantly different from that for groups B2, B3 and B4 (P<0.05). Independent-ٍٍٍSamples T-Test results showed that there was a significant increase in the GIC mean value for groups B2 and B3 after 30 days water storage (P<0.05). The modes of failure were predominantly interfacial or cohesive within the resin.Conclusions: The FRACTURE toughness test method used in this study would be appropriate for analysis of the adhesive zone of resin-ceramic systems. From the results, it can be concluded that micro-mechanical retention by gritblasting the ceramic SURFACES could be sufficient with no need for HF acid etching the ceramic SURFACES when an appropriate silane application procedure is used.

The objective of the present study was to evaluate the mechanical properties of Al/ZrO2 composites produced via vortex technique. Al-356 alloy and ZrO2 particles with average diameter of 0.79 micron were used as the matrix and the reinforcement, respectively. The effect of ZrO2 content and casting temperature on tensile strength and FRACTURE SURFACES of the composites were studied. The results indicate that addition of ZrO2 particles into the matrix significantly increases mechanical properties of aluminum alloy. In this regard, the best tensile strength result was obtained in the specimen containing 15 vol% ZrO2 produced at 750oC which showed an increase of about 60%. The Al-356/ZrO2 composite specimens FRACTURE in a brittle manner with little or no necking has been observed.

The objective of the present study was to evaluate the mechanical properties of Al/ZrO2 composites produced via vortex method. Al-356 alloy and ZrO2 particles with average diameter of 0.79 micron were used as the matrix and the reinforcement, respectively.The results indicate that addition of ZrO2 particles into the matrix significantly increases mechanical properties of aluminum alloy. In this regard, the best tensile strength result was obtained in the specimen containing 15 vol% ZrO2 produced at 750oC which showed an increase of about 60%. The Al-356/ZrO2 composite specimens FRACTURE in a brittle manner with little or no necking observed.

Accumulative roll bonding is new method of severe plastic deformation that in the last decade, utilized to produce many materials. In present study, investigated mechanical properties and FRACTURE mode of microstructure and multi-layered Al-Al fabricated during accumulative roll bonding process.Accumulative roll bonding process applied without using lubricant, in the ambient temperature repeated in seven cycle continuously and without heat treatment between cycles of process that the value of reduction thickness is 50% in each cycle. The evaluation of mechanical properties and FRACTURE mode performed by uniaxial tensile test, micro hardness and scanning electron microscope (SEM) and reveled that by increasing number of ARB cycles, micro hardness and tensile strength increased that increasing rate at initial cycles more than last cycles. Also elongation after first cycle decreased and then increased.The variation for mechanical properties during ARB due to governing cold work and high strain hardening at initial cycles and improve microstructural and grain refinement at last cycles. Maximum value of tensile strength and micro hardness achieved in last cycle (seventh cycle) that compared with primary annealed sheet 241.4 and 106% increased, respectively. Also results of SEM demonstrated that by rising the number of ARB cycles, viewed dimples with shallower and smaller than the initial sample and changed FRACTURE mechanism from ductile to shear ductile.

Statement of Problem: Evaluation of FRACTURE properties is a basic principle for true assessment of brittle materials’ properties. Resin–based composite materials are being used extensively in today’s dentistry. FRACTURE toughness is considered an important parameter for providing useful information about material’s nature, properties and its resistance to FRACTURE. Purpose: The purpose of this study was to evaluate the FRACTURE toughness of a resin composite produced in the country and to compare it with that of other standard materials. Materials and Methods: Four types of resin composite materials were used as follow to prepare 60 specimens (n=15 for each group), A) Tetric Ceram (Ivoclar–Vivadent); B) Brilliant (Coltene-Whaledent); C) SpectrumTPH (Dentsply); and D) Ideal Macoo (Ideal Macoo, Iran). Specimens of 5 mm diameter (± 0.1 mm) and 2 mm depth (±0.1 mm) were prepared in a central notch (90° notch angle) PTFE mold. Then specimens were light cured with two applications of overlapping exposures for a total of 120 s and were stored in distilled water at 37ºC for 48 hours, A cylindrical roller of 3 mm diameter was seated inside the V sections and FRACTURE was accomplished in a universal testing machine at a crosshead speed of 0.5 mm/min. Data were analyzed by one–way ANOVA and post-hoc paired Tukey HSD test with P<0.05 as the limit of significance. Results: The mean KIC and torque to FRACTURE (T) values for each material tested were; A) 3.08±0.42, 16.99±2.34, B) 2.88±0.63, 16.04±1.98; C) 3.40±0.53, 18.75±2.93 and D) 2.87±0.46, 15.78±2.57 MN/m3/2±SD and N/mm±SD, respectively. Group C showed significantly the highest mean KIC and T values among groups tested which was significantly higher than that of group B and D (P<0.05). The mean KIC and T values for groups A, B, and D were not significantly different (P>0.05). Conclusion: From evaluating the FRACTURE properties of materials tested in this study it was concluded that the mean FRACTURE toughness value for SpectrumTPH (Dentsply) was significantly higher than that of Ideal Macoo resin composite material (Ideal Macoo, Iran). The F.T value for Ideal Macoo was considered acceptable as it was not significantly different from that of other resin composite materials tested.  

This paper aimed to experimentally investigate the influence of equal channel angular pressing in the two rotational routes A and BC on the mechanical properties of Al 5086 alloy. The specimens were processed up to 10 passes at 150 º C in a die with 120º internal angle. To evaluate the mechanical properties of the specimens, uni-axial tensile and hardness tests were performed. The results showed that in all passes, route BC had a higher effect on the simultaneous improvement of strength, elongation, and hardness. The FRACTURE surface was investigated using scanning electron microscopy (SEM). The results showed that increasing the number of passes led to the raising of the number of dimples and the better distribution of them for both routes. The textures were also studied using the X-ray diffraction (XRD) analysis. The results showed the dominant texture altered from (111) to (220) plane by increasing the number of passes through both routes.

Percutaneous vertebroplasty is a promising therapeutic technique for pain control in patients with pathologic FRACTUREs of vertebral bodies. Percutaneous vertebroplasty is an appropriate treatment for vertebral pathologic FRACTUREs, which is resistant to other usual treatment. It is a useful and only choice in special cases, because of less tissue damage and there is no risk of open surgery and patient's embolization is rapid. Herein we described the first case of percutaneous vertebroplasty in Yazd shahid sadoughi teaching hospital, which was done in ordybehesht 1386 in a 72 years old male with pathologic FRACTURE of 2 lumbar vertebrae. He was suffered from pain and disability and open surgery was not appropriate treatment for him.

In this paper, we classify SURFACES at a constant distance from the edge of regression on a translation surface of Type 1 in the three dimensional simply isotropic space I13 satisfying some algebraic equations in terms of the coordinate functions and the Laplacian operators with respect to the first, the second and the third fundamental forms of the surface. We also give explicit forms of these SURFACES.

Background and Aim: According to the importance of trigemino cardiac reflex (TCR) and also prevention and management of this reflex in maxillofacial surgeries, the present study was held to evaluate the TCR In lefort I osteotomy. on patients who came to Surgical Department of Buali hospital and the private office in 1386-87.Material and Method: The study was held on 30 patients at the age of 18-39 which were candidate for osteotomy lefort I surgery. TCR was defined as a drop in mean arterial blood pressure (MABP) and heart rate (HR) of more than 10% to the baseline values before maxillary down FRACTURE (D.F) and coinciding with D.F. Hemodynamic parameters such as HR and MABP evaluated with continuous monitoring in different times (before, during and after down FRACTURE of maxilla). Changes in upon characteristics were analyzed.Results: 5 patients were excluded for different reasons and study was completed on 25 patients. Age of the patients was 24.6±1.6, 30% male, and 70% female. The mean HR fell 6.5% from a mean of 94.29±12.12 beats/min, before D.F to a mean of 88.08±13.6 beats/min during D.F, returning to a mean of 93.92±13.09 after D.F. The MABP fell 9.7% from to a mean of 103±15.89 mmHg before D.F to a mean of 92.99±15.19 during the D.F, returning to a mean of 99.69±13.123 after D.F. The HR and MABP after DF were not significantly different from baseline values before the DF. The mean HR drop of more than 10% to the baseline values before DF and coinciding with DF, in 25% of the patients, and also about the MABP, it fell in 45.8% of the patients.Conclusions and suggestions: The present results give evidence that stimulation or manipulation of maxillary branch of the trigeminal nerve can cause TCR, leading to a significant decrease in HR and MABP under a standardized anesthetic protocol. Further studies preferably with a multicenter design are necessary to confirm the nature, description. predisposing and triggering factors and other aspects of this seemingly physiologic phenomenon.

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