Preliminary Study of Bioactive Containing Silica Based Aerogels in Dentistry

Objectives: A variety of bioactive materials have been investigated as substitute materials for diseased or damaged bone tissues in dentistry. Osteoinductive and osteoconductive synthetically produced biomaterial has achieved remarkable progress over the past few years. The aim of this study is to prepare and characterize mesoporous silica based aerogel containing hydroxyapatite and β-tricalcium phosphate as bioactive agents for dental application.
Methods: The preparation of modified silica aerogels was done by sol-gel technology with slow dissolution and then supercritical drying. The bioactive agents were applied in different ratio in the aerogel samples. The alcogels were dried to aerogels a custom designed autoclave by using supercritical carbon dioxide at 80^○C. The samples were heat-treated in a furnace (Wise Therm FM-PH20, Daiham Sci. Co, Korea) in the range of 500 and 1000^○C, 100 degree increments in order to strength the structure of aerogels. The porosities and morphologies of the bioactive inorganic composites were characterized by nitrogen adsorption porosimeter (NOVA® 2200e, Quantachrome Instr., Florida, USA) and Scanning Electron Microscope (Hitachi S-4300, Japan).
Results: The mesoporous bioactive composite containing nano-sized hydroxyapatite showed the highest porosity, the lowest thermal shrinkage and good mechanical properties in contrast to other micro-sized inorganic filled ones. The β-tricalcium phosphate containing samples showed agglomerations on the SEM pictures.
Conclusions: Based on these measurements, it have been demonstrated that mesoporous bioactive modified aerogels were prepared successfully and the inner structure of the composite are variable by the ratio of containing hydroxyapatite and β-tricalcium phosphate. In the near future our plan is to analyze osteointegration process around these bioactive materials in rat calvaria.