Wear and Mechanical Properties of Nano-silica-fused Whisker Composites

Xu, Hockin D.; Quinn, Janet B.; Giuseppetti, Anthony A.

doi:10.1177/154405910408301208

Cited by 48 publications

(47 citation statements)

References 29 publications

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“…For K IC testing, a single edge V-notched beam (SEVNB) method was used. 32,33 A notch with a depth of approximately 500 μm was machined into the specimen using a thin diamond blade with a 150 μm thickness (Buehler, Lake Bluff, IL). 32 Then a diamond polishing paste of 3 μm was placed into the notch tip, and a new razor blade was used to cut the notch further to a total depth of about 700–800 μm, yielding a relatively sharp notch tip.…”

Section: Methodsmentioning

confidence: 99%

“…32,33 A notch with a depth of approximately 500 μm was machined into the specimen using a thin diamond blade with a 150 μm thickness (Buehler, Lake Bluff, IL). 32 Then a diamond polishing paste of 3 μm was placed into the notch tip, and a new razor blade was used to cut the notch further to a total depth of about 700–800 μm, yielding a relatively sharp notch tip. 32 The notch length was measured using an optical microscope (TE2000-S, Nikon) on both sides of the specimen, and then the notch length was averaged.…”

Section: Methodsmentioning

confidence: 99%

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Development of novel self-healing and antibacterial dental composite containing calcium phosphate nanoparticles

Wu¹,

Weir²,

Melo³

et al. 2015

Journal of Dentistry

101

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Objectives Fracture and secondary caries are the primary reasons for dental restoration failure. The objective of this study was to develop a self-healing composite to heal cracks, while containing dimethylaminohexadecyl methacrylate (DMAHDM) for antibacterial function and nanoparticles of amorphous calcium phosphate (NACP) for remineralization. Methods Microcapsules were synthesized with poly(urea-formaldehyde) (PUF) shells containing triethylene glycol dimethacrylate (TEGDMA) and N,N-dihydroxyethyl-p-toluidine (DHEPT) as healing liquid. Composite contained 20 mass% of NACP and 35% glass fillers. In addition, composite contained 0%, 2.5%, 5%, 7.5%, or 10% of microcapsules. A single edge V-notched beam method measured fracture toughness (KIC) and self-healing efficiency. A dental plaque microcosm biofilm model was used to test the antibacterial properties. Results Incorporation of microcapsules up to 7.5% into the composite did not adversely affect the mechanical properties (p > 0.1). Successful self-healing was achieved, with KIC recovery of 65–81% (mean ± sd; n = 6) to regain the load-bearing capability after composite fracture. The self-healing DMAHDM-NACP composite displayed a strong antibacterial potency, inhibiting biofilm viability and lactic acid production, and reducing colony-forming units by 3–4 orders of magnitude, compared to control composite without DMAHDM. Conclusions A dental composite was developed with triple benefits of self-healing after fracture, antibacterial activity, and remineralization capability for the first time. Clinical significance The self-healing, antibacterial and remineralizing composite may be promising for tooth cavity restorations to combat bulk fracture and secondary caries. The method of using triple agents (self-healing microcapsules, DMAHDM, and NACP) may have wide applicability to other dental composites, adhesives, sealants and cements.

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Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Development of novel self-healing and antibacterial dental composite containing calcium phosphate nanoparticles

Wu¹,

Weir²,

Melo³

et al. 2015

Journal of Dentistry

101

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“…The whisker composites have shown superior performance in thermal cycling [23], water-aging [24], and three-body wear [25]. The whisker composites have been shown to be non-cytotoxic and supported cell attachment and proliferation in vitro [26].…”

Section: Introductionmentioning

confidence: 99%

“…25]; however, it did yield a resin composite with high strength, fracture toughness and wear resistance [25]. The powder was then silanized with 4 % 3-methacryloxypropyltrimethoxysilane and 2 % n-propylamine (mass fractions) [25].…”

Section: Fillersmentioning

confidence: 99%

Nanocomposites with Ca and PO4 release: Effects of reinforcement, dicalcium phosphate particle size and silanization☆

2007

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Objectives-Nano-particles of dicalcium phosphate anhydrous (DCPA) were synthesized in our laboratory for the first time and incorporated into a dental resin. Our goal was to develop a mechanically strong dental composite that has Ca and PO 4 ion release to combat tooth caries, and to investigate the effects of whisker reinforcement, DCPA particle size and silanization.Methods-DCPA nano-particles and two larger DCPA particles were used with nano-silica-fused whiskers as fillers in a resin matrix. Composite mechanical properties were measured via three-point flexure, and the release of Ca and PO 4 ions were measured vs. time.Results-Using DCPA nano-particles with a diameter of 112 nm, the composite at a DCPA:whisker mass ratio of 1:1 had a flexural strength (mean ± sd; n = 5) of (112 ± 17) MPa, not significantly different from (112 ± 14) MPa of a commercial non-releasing composite; both were higher than (29 ± 7) MPa for the composite at DCPA:whisker of 1:0 (p < 0.05). The composite with DCPA particle size of 112 nm released Ca to a concentration of 0.85 mmol/L and PO 4 of 3.48 mmol/L, higher than Ca of 0.67 mmol/L and PO 4 of 1.11 mmol/L using DCPA with 12 μm particle size (p < 0.05). Silanization of DCPA increased the composite strength at DCPA:whisker of 1:0 compared to that without silanization, but decreased the Ca and PO 4 release (p < 0.05). Increasing the DCPA particle surface area increased the Ca and PO 4 release.Significance-Decreasing the DCPA particle size increased the Ca and PO 4 release; whisker reinforcement increased the composite strength by 2 to 3 fold. The nano DCPA-whisker composites, with high strength and Ca and PO 4 release, may provide the needed, unique combination of stressbearing and caries-inhibiting capabilities.

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“…Furthermore, in vitro wear of polymer crowns varied widely and ranged from 1.6 6 to 172 mm. 17 Heintze give an explanation of the phenomenon of poor reproducibility of wear results in vitro 18 : most the wear simulators lack control and regulation of force development during dynamic loading of the flat specimens. Because most of the machines are not qualifiable, wear methods simulated by applying the machine may be sound in concept but cannot be validated.…”

Section: Discussionmentioning

confidence: 98%