Properties of elastomeric calcium phosphate cement–chitosan composites

Objective. Self-hardening calcium phosphate cements (CPC) have been shown to be efficacious in a number of clinical applications. For some applications it is desirable to have CPC in a non-rigid resorbable elastomeric matrix. In the present study, chitosan was evaluated as the matrix for preparing C...

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Vydáno v:	Dental materials Ročník 19; číslo 8; s. 797 - 804
Hlavní autoři:	Takagi, Shozo, Chow, Laurence C, Hirayama, Satoshi, Eichmiller, Frederick C
Médium:	Journal Article
Jazyk:	angličtina
Vydáno:	England Elsevier Ltd 01.12.2003
Témata:	Biocompatible Materials - chemistry Calcium phosphate cement Calcium Phosphates - chemistry Chitin - analogs & derivatives Chitin - chemistry Chitosan Chitosan derivatives Compressive Strength Dental Cements - chemistry Dicalcium phosphate anhydrous Durapatite - chemistry Elastomers - chemistry Hardness Humans Hydroxyapatite Materials Testing Mechanical properties Non-rigid Pliability Solubility Stress, Mechanical Tensile Strength Tetracalcium phosphate Water X-Ray Diffraction Non-rigid Chitosan derivatives Mechanical properties Calcium phosphate cement Hydroxyapatite Chitosan Dicalcium phosphate anhydrous Tetracalcium phosphate
ISSN:	0109-5641, 1879-0097
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Shrnutí:	Objective. Self-hardening calcium phosphate cements (CPC) have been shown to be efficacious in a number of clinical applications. For some applications it is desirable to have CPC in a non-rigid resorbable elastomeric matrix. In the present study, chitosan was evaluated as the matrix for preparing CPC-chitosan composites. Methods. Cement specimens were prepared by mixing CPC powder (an equimolar mixture of tetracalcium phosphate and dicalcium phosphate anhydrous) with a chitosan solution at a powder/liquid ratio of 2–2.5. The setting time was measured by a Gilmore needle method. A standard three-point flexural test was used to fracture the specimens at a crosshead speed of 0.5 mm/min. Powder X-ray diffraction analysis was used to determine the conversion of the CPC to hydroxyapatite. Results. The CPC–chitosan composites were more stable in water than conventional CPC. They did not disintegrate even when placed in water immediately after mixing. The CPC–chitosan paste hardened within 10 min in all cases. The 1 d mean flexural modulus (GPa) for the control CPC was 5.3 (0.3) (mean (standard deviation); n=5), and that for CPC–chitosan composites were between 2.7 (0.3) and 4.7 (0.3). The 1 d mean flexural strength (MPa) for the control was 16.6 (1.9), and that for the CPC–chitosan ranged from 4.5 (0.5) and 12.0 (1.0) ( n=5). Chitosan did not interfere the conversion of CPC components to hydroxyapatite. Significance. This study demonstrates that CPC–chitosan composites are stable in a wet environment and have acceptable mechanical strengths for clinical applications.
Bibliografie:	ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-1 content type line 23 ObjectType-Article-1 ObjectType-Feature-2
ISSN:	0109-5641 1879-0097
DOI:	10.1016/S0109-5641(03)00028-9