Development of drug delivery bioceramics cement for vital pulp therapy

This paper demonstrates a dental pulp cell therapy method by using a mixture of a bioceramic materials, simvastatin and collagenase as a drug delivery bioceramic diluent. The drug releasing mechanism and speed are based on a natural diffusion of concentration differences and micro-pinhole sizes on the bioceramic cement, which is composed of the calcium phosphate cement (CPC) and calcium sulfate dihydrate (CSD) powders, respectively. The collagenase and simvastatin can release via the micro-pinhole channels from the cement to not only regenerate dental pulp stem cells but also stimulate the differentiation of pulp cells locally. Three different mixture ratios of CPC and CSD powders were characterized to study the relationship between pinhole sizes and releasing times and speeds. The mixture CPC/CSD ratio of 3∶7, named CPC3CSD7, performs well release profile of the collagenase and simvastatin. The released simvastatin and collagenase are over 80 and 50 percentages, respectively. Furthermore, an in-vitro cell culture experiment was applied to identify the biocompatibility and cultured odontoblasts grown differentiated well on the cement surface.