Basic studies on hydroxy apatite cement: I. Setting reaction.

Y Fukase; S Wada; H Uehara; M Terakado; H Sato; M Nishiyama

doi:10.2334/josnusd.40.71

Home/Archive/PubMed

PubMed · 9680764

Basic studies on hydroxy apatite cement: I. Setting reaction.

Y Fukase·S Wada·H Uehara·M Terakado·H Sato·M Nishiyama

View original source ↗Export metadata ↓

Abstract

Self-setting cements, alpha D-Cement and alpha DT-Cement, were prepared. They consisted of only the calcium phosphates alpha-TCP, TTCP and DCPA. These cements reacted and hardened in a moist environment at 37 degrees C. The powder X-ray diffraction patterns were taken to examine the conversion of their reactions as a function of time. The cements reacted and produced hydroxyapatite. The optimum powder/liquid ratio of alpha D-Cement was 2.0 and that of alpha DT-Cement was 1.8. The initial setting time of alpha D-Cement was 87.5 m and that of alpha DT-Cement was 107.5 m. The component and the product of these cements are calcium phosphates which are the putative minerals in teeth and bones. Therefore, these cements are useful for oral surgery as bone-filling materials.

Explore related subjects

Bone Substitutes Calcium Phosphates Chemical Phenomena Chemistry, Physical Dental Cements Durapatite Hardness Hydroxyapatites Materials Testing Powders Solutions Temperature Time Factors X-Ray Diffraction Journal Article

Keep this discovery

Explore connections, maps & timelines

BibTeX RIS

Y Fukase, S Wada, H Uehara, M Terakado, H Sato, M Nishiyama. 1998. Basic studies on hydroxy apatite cement: I. Setting reaction.. https://doi.org/10.2334/josnusd.40.71

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed1999

Bioactive glasses induce chemiluminescence by human polymorphonuclear leukocytes.

The effect of bioactive glasses on human polymorphonuclear leukocytes (PMNLs) were studied in vitro by a chemiluminescence (CL) assay. Eight different glasses were chosen. All glasses induced a rapid CL response by human PMNLs, which proved to be dose dependent. The CL response also seemed to depend on the durability of the glasses. The least durable glass caused the highest CL response, and highly durable glasses caused only low CL responses by the cells.

Bone Substitutes↗

PubMed1999

[Roentgen spectrometry comparison of currently available bone substitutes].

INTRODUCTION: The crystalline structure of hydroxyapatite (HA) and tricalciumphosphate (TCP) used as bone regeneration materials affects their physical and probably also their biological properties. Varying velocities of the HA solution process seem to be correlated to different results in powder diffraction analysis (RDX) [1], a validated, routine procedure in minerology [2, 6] to analyse crystallized materials. As far we know there are no comparative RDX analyses for the TCP materials in clinical use. GOALS: The dimension and quality of the crystallization of several bone regeneration materials are analysed by RDX. MATERIAL AND METHODS: The materials analysed were divided in different groups: hydroxyapatite, tricalciumphosphate and bioglass. The materials are characterized by the specific intensity curve measurements. RESULTS: The HA products, with the exception of Algipore, seem to be monophasic. Ceros80 and Endobone were the only ones which seem to be totally crystallized. The TCP products Biobase and Cerasorb are nearly monophasic, whereas Ceros82 seems to contain a mixture of 30% HA and 70% beta-TCP. All TCPs show a high crystallization. The bioglasses did--as suspected--not show crystalline structures. DISCUSSION: There are many possible causes for inhomogeneous crystallization of the investigated materials, as they are composites of different foreign ions, extremely small crystals or abnormal (deficient) apatites. How this affects the biological behaviour is not known. SUMMARY: We found differences between the examined materials; how this affects the biological behaviour is unknown. Further investigations are necessary to correlate the characteristics of the materials to the clinical outcome.

Bone Substitutes↗

PubMed1999

In vitro degradation of a novel poly(lactide-co-glycolide) 75/25 foam.

Macroporous poly(lactide-co-glycolide) PLGA 75/25 foams were prepared for application in bone tissue engineering. Their in vitro degradation behaviour was followed over a 30 week period at 37 degrees C and at one of three pHs: (1) pH 5.0, which mimics the acidic environment produced by activated macrophages, (2) pH 7.4, which reproduces normal physiological conditions and (3) an intermediate pH 6.4. The degradation of the PLGA 75/25 foams was studied by measuring changes in mass, molecular weight and morphology. The degradation profile of foams maintained at pH 5.0, 6.4 and 7.4 was similar until week 16, after which foams maintained at pH 6.4 and 7.4 had comparable degradation patterns whereas foams maintained at pH 5.0 degraded faster. For example, mass loss was less than 3% for foams maintained at all three pHs until week 16; however, by week 30, foams maintained at pH 6.4 and 7.4 had lost 30% of their mass whereas foams maintained at pH 5.0 had lost 90% of their mass. Foams maintained at pH 6.4 and 7.4 showed a similar constant decrease in molecular weight over the entire degradation study. Foams maintained at pH 5.0 had a similar rate of molecular weight loss as those maintained at pH 6.4 and 7.4 until week 16, after which the rate of molecular weight loss of foams maintained at pH 5.0 was accelerated. The morphology of the foams maintained at pH 6.4 and 7.4 was unchanged for 25 weeks. Foams maintained at pH 5.0 collapsed after week 18. Thus the PLGA 75/25 foams, described herein, maintained their 3-D morphology at physiological pH for over 6 months, which is an important feature for tissue engineering applications.

Bone Substitutes↗