RETRACTED: Effect of fluorine ion addition on structural, thermal, mechanical, solubility and biocompatibility characteristics of hydroxyapatite nanopowders

Abstract

In this study, the effect of fluorine ion addition on the structural, thermal, mechanical and solubility characteristics of hydroxyapatite nanopowders was investigated. The fluorine substituted hydroxyapatite powders with compositions of Ca 5 (PO 4 ) 3 (OH) 12x F x [x50 (hydroxyapatite), x50?68 (fluorhydroxyapatite) and x50?97 (fluorapatite)] were prepared. The powders were uniaxially pressed and were formed as disc shape. Subsequently, sinterability and thermal stability of disc samples were compared together. Also the effects simultaneously of fluoride content and temperature on the lattice parameters, crystallites size, microstrain and microstructure of the samples were examined. The sintering density and flexural strength of these samples were evaluated with the sintering temperature. Finally, the in vitro dissolution studies of the apatite samples were performed at osteoclastic resorption conditions. The above mentioned experimental results showed that the fluorine content had significant impact on the sintering behaviour, densification and mechanical properties of the hydroxyapatite nanopowders.

Synthesis and solubility of calcium fluoride/hydroxy-fluorapatite nanocrystals for dental applications

“…Although, this law is not strictly obeyed by all types of apatite crystals [50,51], it can give an approximation to determine how much OH groups have been substituted by F À ions in FHAp crystal structure. Rodriguez-Lorenzo et al [30] investigated the influence of F À ion on the structure of synthesized crystals and others have shown its influence on the mechanical properties [52], solubility [53], biocompatibil- ity [54] and stem cell response [55]. A clear relationship was shown between the size of the lattice parameter a and the amount of F substitution.…”

Strength of Material Hap-Borosilicate and Their Sintering Behaviors

“…This material has similarities with human bones 2 . Hydroxyapatite can be obtained by methods: sol-gel, hydrothermal and precipitation [3][4][5][6] Hydroxyapatite can be produced from bovine bones [7][8] . The powder produced bovine bones are extremely brittle or has a very low strength.…”

Effects of Combined Amendments on Growth and Heavy Metal Uptake by Pakchoi (Brassica chinensis L.) Planted in Contaminated Soil

“…In this study, the supplemental hydroxyapatite treatment can increase soil pH and reduce metal bioavailability. Bolisson [26] [27]. In this study, mHAP increased soil pH values more effectively than nHAP.…”