Porous hydroxyapatite-based obturation materials for dentistry
- PDF / 824,400 Bytes
- 10 Pages / 585 x 783 pts Page_size
- 25 Downloads / 216 Views
Miriam Estevez Centro de Física Aplicada y Tecnología Avanzada, Universidad Nacional Autónoma de México, Querétaro, Qro. 76000, México
Haley E. Hagg Lobland and Ly Hoang Laboratory of Advanced Polymers & Optimized Materials, Department of Materials Science and Engineering, University of North Texas, Denton, Texas 76203-5310
J. Rogelio Rodriguez Centro de Física Aplicada y Tecnología Avanzada, Universidad Nacional Autónoma de México, Querétaro, Qro. 76000, México; and Centro de Investigación y Estudios Avanzados del Instituto Politécnico Nacional, Querétaro, Apdo. Postal 1-798, Qro., 76001, México
Susana Vargar Centro de Física Aplicada y Tecnología Avanzada, Universidad Nacional Autónoma de México, Querétaro, Qro. 76000, México (Received 28 August 2007; accepted 4 January 2008)
New porous biomaterials based on hydroxyapatite (HAp) were designed as obturation materials for dental cavities. Synthetic HAp powder with a particle diameter of 150 m was agglutinated using three different polyurethane monocomponents (rigid, semi-rigid, and flexible), enabling the matching of their properties to those of real teeth. Alumina particles were also added in some cases. Our new hybrid materials contain up to 60% HAp. Interconnected pores range in size from 100 to 350 m, while the pore volume fraction varies between 25% and 60%. Most of these materials possess the right morphology for implants and prostheses because their porous structures can be vascularized for bone and tooth ingrowth. Some samples also contain alumina particles to improve the abrasion resistance and to support the stresses produced during mastication. The materials were characterized by x-ray diffraction, scanning electron microscopy, and mechanical testing, along with abrasion, scratch, sliding wear, friction, and staining tests.
I. INTRODUCTION
Numerous different types of biomaterials have been designed for human implants or prostheses, specifically for bone repair or bone ingrowth (e.g., traumatism and bone disease). However considerably less effort has been addressed to implants capable of tooth ingrowth.1–3 For tooth and bone implants, a primary requirement is that the material be bioaccepted, because vascularization requires the material to support cellular activity without eliciting an inappropriate host response on recognition of the foreign molecules (i.e., molecular recognition).4 Second, the morphology must be suitable to allow vascular-
a)
Address all correspondence to this author. e-mail: [email protected] DOI: 10.1557/JMR.2008.0191 J. Mater. Res., Vol. 23, No. 6, Jun 2008
http://journals.cambridge.org
Downloaded: 16 Mar 2015
ization and attachment to the existing bone or tooth substrates.5,6 Morphological specifications for bone-implant materials require a pore size in the range of 100–400 m, with the pores being interconnected and comprising a volume fraction between 50% and 70%.7 For tooth implants, on the other hand, the mean optimal pore size is 2.90 ± 0.22 m (standard deviation), which is considerably smaller.8 A precise densitom
Data Loading...
