Bioactivity of Bioceramic Materials Used in the Dentin-Pulp Complex Therapy: A Systematic Review

Dentistry-applied bioceramic materials are ceramic materials that are categorized as bioinert, bioactive and biodegradable. They share a common characteristic of being specifically designed to fulfil their function; they are able to act as root canal sealers, cements, root repair or filling materials. Bioactivity is only attributed to those materials which are capable of inducing a desired tissue response from the host. The aim of this study is to present a systematic review of available literature investigating bioactivity of dentistry-applied bioceramic materials towards dental pulp stem cells, including a bibliometric analysis of such a group of studies and a presentation of the parameters used to assess bioactivity, materials studied and a summary of results. The research question, based on the PICO model, aimed to assess the current knowledge on dentistry-based bioceramic materials by exploring to what extent they express bioactive properties in in vitro assays and animal studies when exposed to dental pulp stem cells, as opposed to a control or compared to different bioceramic material compositions, for their use in the dentin-pulp complex therapy. A systematic search of the literature was performed in six databases, followed by article selection, data extraction, and quality assessment. Studies assessing bioactivity of one or more bioceramic materials (both commercially available or novel/experimental) towards dental pulp stem cells (DPSCs) were included in our review. A total of 37 articles were included in our qualitative review. Quantification of osteogenic, odontogenic and angiogenic markers using reverse transcriptase polymerase chain reaction (RT-PCR) is the prevailing method used to evaluate bioceramic material bioactivity towards DPSCs in the current investigative state, followed by alkaline phosphatase (ALP) enzyme activity assays and Alizarin Red Staining (ARS) to assess mineralization potential. Mineral trioxide aggregate and Biodentine are the prevalent reference materials used to compare with newly introduced bioceramic materials. Available literature compares a wide range of bioceramic materials for bioactivity, consisting mostly of in vitro assays. The desirability of this property added to the rapid introduction of new material compositions makes this subject a clear candidate for future research.