The Effects of Hydroxyapatite on Bonding Strength between Dental Luting Cement and Human Teeth

2005 ◽  
Vol 284-286 ◽  
pp. 953-956 ◽  
Author(s):  
S.I. Yoon ◽  
Yong Keun Lee ◽  
Yeon Ung Kim ◽  
Min Chul Kim ◽  
Kyoung Nam Kim ◽  
...  

This study aimed to investigate the effects of hydroxyapatite on bonding strength between dental luting cement and human teeth. In the previous study, bonelike forming ability by mixing hydroxyapatite with several bone cements was reported in a protein-free acellular simulated body fluid with ion concentrations nearly equal to those of the human blood plasma. Therefore in this experiment, we assumed that if bonelike apatite layer could form between dental luting cement and human teeth, the bonding strength between the two would improve. In addition, we expected the HA mixed dental luting cement to improve the physical properties. Fuji I glass ionomer and Relyx™ glass ionomer cement were the selected dental luting cements and the film thickness, setting time and compressive strength were measured mixing various concentrations of hydroxyapatite. Glass ionomer cement with the most superior physical properties(Fuji I ; 20% hydroxyapatite, Relyx™ ; 15% hydroxyapatite) was immersed in the simulated body fluid for three weeks and the surface was observed under SEM after measuring the bonding strength. As the concentration of HA increased, the film thickness of hydroxyapatite-glass ionomer cement decreased, the setting time increased, and the compressive strength increased. The most noteworthy results were that bonding strength increased, and that bonelike apatite formed on the tooth surface when observed under SEM.

2006 ◽  
Vol 309-311 ◽  
pp. 885-890 ◽  
Author(s):  
S.I. Yoon ◽  
Yong Keun Lee ◽  
Kyoung Nam Kim ◽  
S.O. Kim ◽  
H.K. Son ◽  
...  

Previous studies have shown that hydroxyapatite increases the bonding strength of dental luting cement with human teeth by forming bone-like apatite when it is added to cement. However, due to the low solubility of the hydroxyapatite, its ability to form bone-like apatite decreases in protein-free acellular simulated body fluid with ion concentrations nearly equal to those of the human blood plasma. The purpose of this experiment was to increase the formation of bone-like apatite by mixing hydroxyapatite with β-TCP of high solubility. RelyXTM glass ionomer cement(3M/ESPE, USA) was used as dental luting cement. Film thickness, setting time, and compressive strength was measured for each group of 15% hydroxyapatite, 15% β-TCP, and 15% mixed hydroxyapatite and β-TCP (85:15). Every specimen of each group was immersed in the simulated body fluid for four week before measuring bonding strength, and then their sectional surface was observed under SEM. The most noteworthy result was that the group containing β-TCP produced more amount of bone-like apatite compared with the group composed of only hydroxyapatite.


2021 ◽  
Vol 1 (39) ◽  
pp. 83-90
Author(s):  
Hoa Thi Hong Huynh ◽  
Minh Ngoc Huynh ◽  
Minh Quang Do

Glass ionomer cement (GIC), a thermoplastic polymer, is toughed by ionic bonding is used in dentistry as a filling material. The glass-powder used has some disadvantages such as: poor strength and toughness, and instability in water. Therefore, the aim of this work is to enhance mechanical and fluoride release properties of the GICs by modifying ingredients. The results show that the compressive strength reached to from 60.5 to 86.2 MPa, the setting time met the ISO 9917-1:2007 quality standard. This also suggests that, in addition to 35% PAA in water with Mw of 100,000, 5% of Maleic acid and 5% Tartaric acid to produce GIC which can be used as suitable materials for improving its fluoride ion release over 28 days. The average diameter (dmean) of glass powder for GICs was 14.3 mm; S.P. Surface area was 10,358 cm2=cm3, improvement of liquid composition includes 35% PAA in water with Mw of 100,000, 5% of Maleic acid and 5% Tartaric acid. The compressive strength after curing 28-day reaches from 60.5 to 86.2 MPa and the setting time responds with ISO 9917-1:2007. In conclusion, it was found that the GIC can release fluoride ions (F-) for the during of the examination period.


2007 ◽  
Vol 330-332 ◽  
pp. 831-834
Author(s):  
Ju Hye Lee ◽  
Sang Bae Lee ◽  
Kyoung Nam Kim ◽  
Kwang Mahn Kim ◽  
Yong Keun Lee

In this study, the antibacterial effects of glass ionomer cement containing silver-zeolite were evaluated. New antibacterial glass ionomer cements with silver-zeolite were prepared as follows. Silver-zeolite (1, 3, and 5 wt%) was incorporated into the glass ionomer cement powder and then mixed with the polyacidic liquid at the ratio recommended by the manufacturer. Agar diffusion test was used to evaluation of antibacterial effect. Setting time, film thickness and compressive strength were also determined. Paired samples t-tests and ANOVA were used, and P<0.05 was considered significant. Film thickness and setting time were increased dependent on the amount of silver-zeolite. Glass ionomer cement with 1 wt% of silver-zeolite seemed to increase the compressive strength. However, increasing ratio of compressive strength was diminished beyond 3 wt%. Glass ionomer cements containing silver-zeolite have been successfully demonstrated to have antimicrobial effects on S. mutants in vitro. These results indicate that glass ionomer cement containing silver-zeolite have the potential to enhance antibacterial of dental cement in oral cavity.


2015 ◽  
Vol 815 ◽  
pp. 373-378 ◽  
Author(s):  
Shi Qun Li ◽  
Bao Hui Su ◽  
Jun Guo Ran ◽  
Jun Wang ◽  
Ling Ling Yan ◽  
...  

Aiming at inadequate mechanical properties of Glass ionomer cement (GIC) commonly used in dental clinic, commercial and melt quenched GIC powders as control groups, homemade GIC powder was prepared by sol–gel route and modified by Nb2O5. The GIC samples were characterized by X-ray Diffraction (XRD), particle size analysis, Scanning Electron Microscope (SEM) and Fourier Transform Infrared (FT-IR). The compressive strength, Vickers hardness, working and net setting time were tested. The data was analyzed by one-way ANOVA. The XRD results showed that commercial, melt quenched and sol gel GIC powders were similar amorphous. D90 of three GIC powders and Nb2O5 powder were 26 μm, 17 μm, 29 μm and 19 μm respectively. 5% Nb2O5-GIC exhibited the highest values of compressive strength and Vickers hardness, which were 112.93 Mpa, 139.48 MPa and 142.25 MPa respectively, increased 19.11%, 30.56% and 16.51% (P <0.05); the Vickers hardness were 35.15 MPa, 36.23 MPa and 37.62 MPa, increased 18.03%, 29.95% and 16.32% (P <0.05) compared to those of unmodified GICs as well. There was no significant change of the FT-IR characteristic peaks of modified GIC. The working time of three kinds of GIC were 4'58 ", 3'28" and 4'10 ", the net setting time were 5'16", 3'15 "and 4'38" (standard is 1.5-6 minutes). It was concluded that the dispersion stiffened effect of niobium oxide could improve the mechanical properties of the filling GIC without affecting the clinical operating performance.


2015 ◽  
Vol 62 (1) ◽  
pp. 7-13 ◽  
Author(s):  
Sameer Makkar ◽  
Ruchi Vashisht ◽  
Anita Kalsi ◽  
Pranav Gupta

Summary Introduction Throughout the history of dentistry, a wide variety of materials such as gold-foil, silver posts, amalgam, zinc oxide eugenol, glass ionomer cements, mineral trioxide aggregate have been used as retrograde fillings. Altered pH in periapical lesions can affect push-out bond strength of these materials. The aim of this study was to evaluate the effect of altered pH on push-out bond strength of Biodentin, Glass ionomer cement (GIC), Mineral trioxide aggregate (MTA) and Theracal. Material and Methods Forty-eight dentin slices of extracted single-rooted human teeth were sectioned and their canal portion instrumented to achieve a diameter of 1.4 mm. The specimens were then assigned into the four groups (one group for each material) with 12 samples in each group. All groups were further divided into 3 subgroups (with 4 specimens in each subgroup): acidic (butyric acid buffered at pH 6.4), neutral (phosphate buffer saline solution at pH 7.4) and alkaline (buffered potassium hydroxide at pH 8.4). Samples were incubated for 4 days at 37°C in acidic, neutral or alkaline medium. Push-out bond strength was measured using a Universal Testing Machine. The slices were examined under a stereomicroscope to determine the nature of bond failure. Results GIC showed the highest bond strength (33.33MPa) in neutral and acidic medium (26.75MPa) compared to other materials. Biodentin showed the best result in alkaline medium. Conclusion Altered pH level affected push-out bond strength of root end materials. GIC demonstrated good push-out bond strength that increased with decrease of pH whereas newer materials Biodentin and Theracal showed satisfying results in altered pH.


2013 ◽  
Vol 3 ◽  
pp. 245-248 ◽  
Author(s):  
P Sri Chandana ◽  
Swapna Munaga ◽  
M Narender Reddy ◽  
Dishasaraswathi Devabhaktuni ◽  
Challakolusu Lakshmi Swathi

2007 ◽  
Vol 21 (3) ◽  
pp. 204-208 ◽  
Author(s):  
André Mallmann ◽  
Jane Clei Oliveira Ataíde ◽  
Rosa Amoedo ◽  
Paulo Vicente Rocha ◽  
Letícia Borges Jacques

The purpose of this study was to evaluate the compressive strength of two glass ionomer cements, a conventional one (Vitro Fil® - DFL) and a resin-modified material (Vitro Fil LC® - DFL), using two test specimen dimensions: One with 6 mm in height and 4 mm in diameter and the other with 12 mm in height and 6 mm in diameter, according to the ISO 7489:1986 specification and the ANSI/ADA Specification No. 66 for Dental Glass Ionomer Cement, respectively. Ten specimens were fabricated with each material and for each size, in a total of 40 specimens. They were stored in distilled water for 24 hours and then subjected to a compressive strength test in a universal testing machine (EMIC), at a crosshead speed of 0.5 mm/min. The data were statistically analyzed using the Kruskal-Wallis test (5%). Mean compressive strength values (MPa) were: 54.00 ± 6.6 and 105.10 ± 17.3 for the 12 mm x 6 mm sample using Vitro Fil and Vitro Fil LC, respectively, and 46.00 ± 3.8 and 91.10 ± 8.2 for the 6 mm x 4 mm sample using Vitro Fil and Vitro Fil LC, respectively. The resin-modified glass ionomer cement obtained the best results, irrespective of specimen dimensions. For both glass ionomer materials, the 12 mm x 6 mm matrix led to higher compressive strength results than the 6 mm x 4 mm matrix. A higher variability in results was observed when the glass ionomer cements were used in the larger matrices.


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