scholarly journals Fracture toughness of experimental mica-based glass-ceramics and four commercial glass-ceramics restorative dental materials

2019 ◽  
Vol 38 (3) ◽  
pp. 378-387 ◽  
Author(s):  
Thapanee SRICHUMPONG ◽  
Pimnida PHOKHINCHATCHANAN ◽  
Noparat THONGPUN ◽  
Duangrudee CHAYSUWAN ◽  
Kallaya SUPUTTAMONGKOL
Keyword(s):  
Fracture Toughness ◽  
Dental Materials ◽  
Glass Ceramics ◽  
Commercial Glass ◽  
Restorative Dental Materials

Effect of Heat Treatment Time on Properties of Mica-Based Glass-Ceramics for Restorative Dental Materials

2016 ◽  
Vol 702 ◽  
pp. 23-27 ◽  
Author(s):  
Thapanee Srichumpong ◽  
Kallaya Suputtamongkol ◽  
Warat Chinpanuwat ◽  
Pronbadin Nampachoke ◽  
Jia Bai ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Crystal Size ◽  
Treatment Time ◽  
Dental Materials ◽  
Glass Ceramics ◽  
Nucleation Time ◽  
Human Enamel ◽  
Restorative Dental Materials ◽  
Dental Applications ◽  
Stage Heat Treatment

The objective of this research is to focus improving the properties of machinable mica-based glass-ceramics in order for restorative dental materials. The glass-ceramics derived from the SiO2- Al2O3-MgO-MgF2-SrCO3-CaCO3-CaF2-P2O5 system were produced by a two-stage heat treatment. It was elucidated that the optimum nucleation and the crystallization temperatures were at 643°C and 892°C. The various heat treatment times in the first stage were applied as 3, 6, 12, 24, 48 and 72 h, respectively, on the optimum nucleation temperature to produce mica-based glass-ceramics. XRD results showed that specimens of variety of nucleation time had similar crystalline structures such as calcium-mica, fluorapatite, stishovite, anorthite, strontiumapatite and forsterite phases. The microstructures of glass-ceramics were observed by SEM basically as interlocked plate-like and needle-like microstructures of mica and fluorapatite, respectively, in all specimens. Furthermore, different heat treatment times influenced on the revealed crystal size of the glass-ceramics; the longer heat treatment, the smaller crystals. The resultant glass-ceramics gave the results of biaxial flexural strength (178-224 MPa) and Vickers hardness (295-393 HV) increasing with the formation of the interconnected mica phases which contributed to improve the machinability. The values of the properties were comparable to those of human enamel and suitable for some restorative dental applications.

scholarly journals Effects of ionizing radiation on surface properties of current restorative dental materials

2021 ◽  
Vol 32 (6) ◽  
Author(s):  
Débora Michelle Gonçalves de Amorim ◽  
Aretha Heitor Veríssimo ◽  
Anne Kaline Claudino Ribeiro ◽  
Rodrigo Othávio de Assunção e Souza ◽  
Isauremi Vieira de Assunção ◽  
...  
Keyword(s):  
Ionizing Radiation ◽  
Surface Properties ◽  
Resin Composite ◽  
Dental Materials ◽  
Glass Ionomer Cement ◽  
Contact Angles ◽  
Glass Ionomer ◽  
Post Radiation ◽  
Restorative Dental Materials ◽  
Ionomer Cement

AbstractTo investigate the impact of radiotherapy on surface properties of restorative dental materials. A conventional resin composite—CRC (Aura Enamel), a bulk-fill resin composite—BFRC (Aura Bulk-fill), a conventional glass ionomer cement—CGIC (Riva self cure), and a resin-modified glass ionomer cement—RMGIC (Riva light cure) were tested. Forty disc-shaped samples from each material (8 mm diameter × 2 mm thickness) (n = 10) were produced according to manufacturer directions and then stored in water distilled for 24 h. Surface wettability (water contact angle), Vickers microhardness, and micromorphology through scanning electron microscopy (SEM) before and after exposition to ionizing radiation (60 Gy) were obtained. The data were statistically evaluated using the two-way ANOVA and Tukey posthoc test (p < 0.05). Baseline and post-radiation values of contact angles were statistically similar for CRC, BFRC, and RMGIC, whilst post-radiation values of contact angles were statistically lower than baseline ones for CGIC. Exposition to ionizing radiation statistically increased the microhardness of CRC, and statistically decreased the microhardness of CGIC. The surface micromorphology of all materials was changed post-radiation. Exposure to ionizing radiation negatively affected the conventional glass ionomer tested, while did not alter or improved surface properties testing of the resin composites and the resin-modified glass ionomer cement tested.

scholarly journals Eco-Compatible Construction Materials Containing Ceramic Sludge and Packaging Glass Cullet

2021 ◽  
Vol 11 (8) ◽  
pp. 3545
Author(s):  
Fernanda Andreola ◽  
Isabella Lancellotti ◽  
Paolo Pozzi ◽  
Luisa Barbieri
Keyword(s):  
Raw Materials ◽  
Construction Materials ◽  
Treatment Plant ◽  
Glass Ceramics ◽  
Chemical Properties ◽  
Linear Shrinkage ◽  
Glass Cullet ◽  
Commercial Glass ◽  
Packaging Glass ◽  
And Chemical Properties

This research reports results of eco-compatible building material obtained without natural raw materials. A mixture of sludge from a ceramic wastewater treatment plant and glass cullet from the urban collection was used to obtain high sintered products suitable to be used as covering floor/wall tiles in buildings. The fired samples were tested by water absorption, linear shrinkage, apparent density, and mechanical and chemical properties. Satisfactory results were achieved from densification properties and SEM/XRD analyses showed a compact polycrystalline microstructure with albite and wollastonite embedded in the glassy phase, similar to other commercial glass-ceramics. Besides, the products were obtained with a reduction of 200 °C with respect to the firing temperatures of commercial ones. Additionally, the realized materials were undergone to leaching test following Italian regulation to evaluate the mobility of hazardous ions present into the sludge. The data obtained verified that after thermal treatment the heavy metals were immobilized into the ceramic matrix without further environmental impact for the product use. The results of the research confirm that this valorization of matter using only residues produces glass ceramics high sintered suitable to be used as tile with technological properties similar or higher than commercial ones.

scholarly journals Mechanical Properties of CaO–Al2O3–SiO2 Glass-Ceramics Precipitating Hexagonal CaAl2Si2O8 Crystals

Crystals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 393
Author(s):  
Kei Maeda ◽  
Kosho Akatsuka ◽  
Gaku Okuma ◽  
Atsuo Yasumori
Keyword(s):  
Fracture Toughness ◽  
Liquidus Temperature ◽  
Fracture Behavior ◽  
Glass Ceramics ◽  
High Fracture Toughness ◽  
Flexural Test ◽  
Toughening Mechanism ◽  
High Fracture ◽  
X Ray ◽  
Microcrack Toughening

Fracture behavior via a flexural test for a newly found CaO–Al2O3–SiO2 (CAS) glass-ceramic (GC) was compared with that of enstatite GC and mica GC, which are well-known GCs with high-fracture toughness and machinability, respectively. By focusing on the nonelastic load–displacement curves, CAS GC was characterized as a less brittle material similar to machinable mica GC, compared with enstatite GC, which showed higher fracture toughness, KIC. The microcrack toughening mechanism in CAS GC was supported by the nondestructive observation of microcracks around the Vickers indentation using the X-ray microcomputed tomography technique. The CAS GC also showed higher transparency than mica GC due to its low crystallinity. Moreover, the precursor glass had easy formability due to its low-liquidus temperature.

Measurement of the fluorescence of restorative dental materials using a 655-nm diode laser

2001 ◽  
Author(s):  
Fatima A. A. Zanin ◽  
Dilma H. Souza-Campos ◽  
Sissi Zanin ◽  
Aldo Brugnera, Jr. ◽  
Jesus D. Pecora ◽  
...  
Keyword(s):  
Diode Laser ◽  
Dental Materials ◽  
Restorative Dental Materials

scholarly journals Pengaruh Penambahan Hidroksiapatit dari Cangkang Telur Ayam Terhadap Kekerasan Permukaan GIC

2016 ◽  
Vol 5 (2) ◽  
pp. 8
Author(s):  
Putri Ajri Mawadara ◽  
Martha Mozartha ◽  
Trisnawaty K
Keyword(s):  
Dental Materials ◽  
Surface Hardness ◽  
T Test ◽  
Control Group ◽  
System A ◽  
Significant Difference ◽  
Calcium Source ◽  
Chicken Eggshell ◽  
Restorative Dental Materials ◽  
Experimental Group

Hydroxyapatite (HA) is a bioceramic with excellentbiocompatible properties, and composition and crystal structure similar to apatite in the human dental structure and skeletal system. A number of researchers have attempted to evaluate the effect of the addition of HA powders to increasemechanical properties of restorative dental materials. In this study, HA was synthesized using chicken eggshell as calcium source for synthesizing HA by using precipitation technique. The aim of this study was to determine the effect of incorporation of eggshell-derived HA on the surface  hardness GIC (Fuji IX GP). Specimens were divided into two groups: group GIC without incorporation of HA as control group (n = 16) and group GIC with incorporation of 5% HA as experimental group (n = 16). Total of specimens were 32 cylinders 5mm diameter and 2mm height. Surface hardness GIC was measured with vickers microhardness tester. Data wasanalyzed by unpaired T-test. The mean of surface hardness for GIC control group was 51.37 ± 1,63VHN and the experimental group was 56.60 ± 1,22HVN. The results T-test showed a significant difference between groups (p<0.05). It can be concluded thatincorporation of eggshell-derivedHA could increasesurface hardness of GIC.

Assessing Restorative Dental Materials: 1. Test Methods and Assessment of Results

Dental Update ◽  
2002 ◽  
Vol 29 (4) ◽  
pp. 188-194 ◽  
Author(s):  
F.J.T. Burke ◽  
A.C.C. Shortall ◽  
E.C. Combe ◽  
T.C. Aitchison
Keyword(s):  
Dental Materials ◽  
Test Methods ◽  
Restorative Dental Materials
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