2003 ◽  
Vol 11 (3) ◽  
pp. 162-167 ◽  
Author(s):  
Linda Wang ◽  
Paulo Henrique Perlatti D'Alpino ◽  
Lawrence Gonzaga Lopes ◽  
José Carlos Pereira

A wide variety of dental products that are launched on the market becomes the correct selection of these materials a difficult task. Although the mechanical properties do not necessarily represent their actual clinical performance, they are used to guide the effects of changes in their composition or processing on these properties. Also, these tests might help somehow the clinician to choose once comparisons between former formulations and new ones, as well as, with the leading brand, are highlighted by manufactures. This paper presents a review of the most important laboratory tests. In this manner, the knowledge of these tests will provide a critical opinion related to the properties of different dental materials.


Author(s):  
K. J. Chun ◽  
C. Y. Kim ◽  
J. Y. Lee

Dental restorative materials including amalgam, dental ceramic, gold alloy, dental resin, zirconia, and titanium alloy are used to reconstruct damaged teeth, as well as to recover their function. In this study, the mechanical properties of various dental restorative materials were determined using test specimens of identical shape and dimension under the same three-point bending test condition, and the test results were compared to enamel and dentin. The maximum bending force of enamel and dentin was 6.9 ± 2.1 N and 39.7 ± 8.3 N, and the maximum bending deflection was 0.12 ± 0.02 mm and 0.25 ± 0.03 mm, respectively. The maximum bending force of amalgam, dental ceramic, gold alloy, dental resin, zirconia, and titanium alloy were 1.9 ± 0.4 N, 2.7 ± 0.6 N, 66.9 ± 4.1 N, 2.7 ± 0.3 N, 19.0 ± 2.0 N, and 121.3 ± 6.8 N, respectively, and the maximum bending deflection was 0.20 ± 0.08 mm, 0.28 ± 0.07 mm, 2.53 ± 0.12 mm, 0.37 ± 0.05 mm, 0.39 ± 0.05 m, and 2.80 ± 0.08 mm, respectively. The dental restorative materials that possessed greater maximum bending force than that of enamel were gold alloy, zirconia, and titanium alloy. Gold alloy and titanium alloy had greater maximum bending force than dentin. The dental restorative materials that possessed greater maximum bending deflection than that of enamel were all of the dental restorative materials, and the dental restorative materials that possessed greater maximum bending deflection than that of dentin were all of the dental restorative materials except amalgam. The appropriate dental restorative materials for enamel are gold alloy and zirconia and for dentin is gold alloy concerning the maximum bending force and the maximum bending deflection. These results are expected to aid dentists in their choice of better clinical treatment and to contribute to the development of dental restorative materials that possess properties that are most similar to the mechanical properties of dental hard tissue.


2022 ◽  
Vol 6 (1) ◽  
pp. 17
Author(s):  
Hiroshi Ikeda ◽  
Yohei Kawajiri ◽  
Minako Kibune Sodeyama ◽  
Haruka Takesue Yano ◽  
Yuki Nagamatsu ◽  
...  

SiO2-poly(2-hydroxyethyl methacrylate) (pHEMA)-based composites have been widely used as biomaterials owing to their biocompatibility. However, they have not yet been applied as tooth restorative materials because of their poor mechanical properties. In the present paper, we develop a novel SiO2/pHEMA-based composite with a polymer-infiltrated network (PICN) structure for use in dental restorative materials. A mixture of SiO2 nanoparticles and a poly(vinyl alcohol) binder was sintered at 950 °C to fabricate a porous SiO2 block. A monomer mixture containing 70 wt%-HEMA/30 wt%-ethylene glycol dimethacrylate and a benzoyl peroxide initiator was infiltrated into the porous SiO2 block and heat-polymerized to fabricate the SiO2/pHEMA-based composite with a PICN structure. The composite was characterized according to its mechanical properties, surface free energy, and bonding properties with a dental adhesive. The flexural strength was 112.5 ± 18.7 MPa, the flexural modulus was 13.6 ± 3.4 GPa, and the Vickers hardness was 168.2 ± 16.1, which are similar values to human teeth. The surface free energy of the polar component of the composite was 19.6 ± 2.5 mN/m, suggesting that this composite has an active surface for bonding with the adhesive. The composite bonded well to the adhesive, in the presence of a silane coupling agent. The SiO2/pHEMA-based composite was demonstrated to be a potential candidate for dental restorative materials.


Polymers ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 332 ◽  
Author(s):  
Loredana Tammaro ◽  
Anna Di Salle ◽  
Anna Calarco ◽  
Ilenia De Luca ◽  
Francesco Riccitiello ◽  
...  

Resin-based composites are widely used as dental restorative materials due to their excellent properties. They must have high modulus, high hardness, and be chemically inert while minimizing moisture uptake. To fulfill these higher standard prerequisites and properties, continuous improvements in each of their components are required. This study develops novel composites with multiple biofunctions. Light-cured Bis-GMA/TEGDMA dental resin (RK)/layered double hydroxide intercalated with fluoride ions (LDH-F)/calcium bentonite (Bt) hybrid composites were prepared. The loading ratio of LDH-F to Bt was varied, ranging from 2.5/2.5 to 10/10 parts per hundred RK and structural, mechanical, and biological properties were studied. The incorporation of even small mass fractions (e.g., 2.5 wt% of LDH-F and 2.5 wt% of Bt) in RK dental resin significantly improved the mechanical properties of the pristine resin. The synthetized materials showed antibacterial and antibiofilm effects against three bacterial strains isolated from healthy volunteers’ saliva (Streptococcus spp., Bacteroides fragilis, and Staphylococcus epidermidis) without affecting its ability to induce dental pulp stem cells differentiation into odontoblast-like cells. The capability to balance between the antibiofilm activity and dental pulp stem cells differentiation in addition with improved mechanical properties make these materials a promising strategy in preventive and restorative dentistry.


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