Suitability evaluation of sol-gel derived Si-substituted hydroxyapatite for dental and maxillofacial applications through in vitro osteoblasts response.
Si-hydroxyapatite (Si-HAP) has been used in orthopedic, dental, and maxillofacial surgery as a bone substitute.


OBJECTIVE
The aim of this investigation was to study the effect of Si substitution into the hydroxyapatite matrices and evaluate the biocompatibility effects of Si-HAP material in vitro with human osteoblasts.


METHODS
Silicon-substituted hydroxyapatite (Si-HAP) bioceramic materials were prepared by incorporating small amounts of silicon into the structure of hydroxyapatite [Ca10(PO4)6(OH)2, HAP] through a sol-gel method. A series of silicon substitutions ranging from 0, 1, 3 and 5 mol%, which are comparable to the measured silicon contents in natural bone, were performed.


RESULTS
Single-phase Si-HAP was obtained upon calcining the as-prepared powders up to 800 degrees C since no secondary phases, such as tricalcium phosphate (TCP), tetracalcium phosphate (TeCP) or calcium oxide (CaO), were identified by X-ray diffraction analysis. The effects of silicon-substituted hydroxyapatite (Si-HAP) materials towards the responses of human osteoblast-like (HOB) cells were investigated and compared with pure hydroxyapatite.


CONCLUSIONS
The Si-HAP indicated a significant increase in cell growth density with culture time irrespective of the amount of Si substituted in HAP. A high Si content (5 mol%) appears to promote rapid bone mineralization, since large amount of calcium phosphate minerals started to develop across the ECM by day 31 for a sample containing 5 mol% Si. On the other hand, a high Si content may result in fast dissolution of the material, owing to a decrease of HAP crystallite size, which might not be ideal for cell attachment for prolonged time periods. An optimum level of Si appears to exist at 3 mol%, which balances these effects.
Balamurugan
A
A
Department of Ceramics and Glass Engineering, University of Aveiro, CICECO, 3810-193 Aveiro, Portugal.
Rebelo
A H S
AH
Lemos
A F
AF
Rocha
J H G
JH
Ventura
J M G
JM
Ferreira
J M F
JM
D001672:Biocompatible Materials / Q000737:chemistry / Q000494:pharmacology*; D002113:Calcification, Physiologic / Q000187:drug effects; D002448:Cell Adhesion / Q000187:drug effects; D002460:Cell Line; D049109:Cell Proliferation / Q000187:drug effects; D048429:Cell Size / Q000187:drug effects; D003461:Crystallography; D003764:Dental Materials / Q000737:chemistry / Q000494:pharmacology*; D017886:Durapatite / Q000737:chemistry / Q000494:pharmacology*; D004577:Electron Probe Microanalysis; D006358:Hot Temperature; D006801:Humans; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D010006:Osteoblasts / Q000187:drug effects*; D044367:Phase Transition; D011208:Powders; D017655:Silicon Compounds / Q000737:chemistry / Q000494:pharmacology*; D012995:Solubility; D013997:Time Factors; D014961:X-Ray Diffraction
D001672:Biocompatible Materials; D003764:Dental Materials; D011208:Powders; D017655:Silicon Compounds; D017886:Durapatite