Salivary bioMarkers of bOne turnOver in response to biomaterials for restorative dentistry - a Tool for salivary monitoring

Dental bone defects are common problems that may arise from infections, trauma, congenital syndromes, cancer, and aging. In this context, implants or restorative materials are needed to replace the damaged tissue, but their connection with the host bone tissue must be ensured.
The materials used in these procedures must provide the best structural environment for cell development during the bone healing process. In the human body, the success of the implants or endodontic treatments (when natural teeth can be saved/preserved) is directly related to biocompatibility and the osteoimmune response.
For instance, activated T cells can surface-express the receptor activator of nuclear factor-kappa B ligand (RANKL) to stimulate osteoclast production and bone resorption. RANKL binds to the receptor activator of nuclear factor-κβ (RANK) on the surface of pro-osteoblasts, activating the RANKL/RANK signaling pathway and directly promoting osteoclast formation and differentiation. Several of these bone formation/regulation molecules are released during the bone remodeling processes, which may allow their use as bone turnover biomarkers. Several salivary components, such as immunoglobulins, proinflammatory cytokines and proteins are being studied as biomarkers for screening the cases with soft tissue and hard tissue changes due to periodontitis, which supports our strategy (OralPreciseMed Project – SalivaTec/CIIS).
New calcium silicate materials can induce an adequate cell/tissue response, stimulating proliferation and enhancing the osteogenic differentiation of distinct precursor populations.
Despite the several studies of root canal sealers to date, the biocompatibility, anti-inflammatory, and osteogenic differentiation is not fully known.
Our proposal aims to test the osteogenic potential new calcium silicate–based endodontic sealers by evaluating the expression of key bone remodeling molecules in human osteoblast-like cells (MG63) in culture. Afterwards, we will test them in endodontic procedures following the ethical principles approved by CES-UCP. The detection and quantification of the selected osteogenic biomarkers in saliva, will allow to combine them in order to build an effective monitoring panel for their validation as salivary bone remodeling biomarkers.

SMOOT tasks:
I. Effect of new calcium silicate on osteoblast proliferation and osteogenic gene expression.
After cell exposure (3 and 7 days), qRT-PCR will be used to evaluate the expression of the target genes (i.e.: RUNX2, Col1a1, GAPDH).
II. Endodontic treatment and sample collection.
Calcium silicate–based endodontic sealers will be used to treat patients in the CDU and saliva samples will be collected for a five-month longitudinal study (according CES-UCP).
III. Detection and quantification of osteogenic biomarkers in saliva.
The expression of genes related to odontogenic/osteogenic markers will be evaluated using realtime RT-PCR.
IV. Data analysis and integration.
Global data will be integrated to determine association of the different biomarkers with the process of bone remodeling. To support data integration and statistical analysis will be used.