Project Details
Projekt
Establishing adhesion inside the root canal: identifying parameters of the composite-root-dentine interzones that modulate propensity to failure
Subject Area
Biomaterials
Term
since 2021
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 396127899
Tightly sealed composite restorations are of utmost importance for long-term success of root-canal treated teeth. However, such restorations, adhesively bonded inside root canals, are more prone to failure compared to composite fillings in crown dentine.Our work clearly shows that the foundations of bond degeneration are already laid in the first minutes of placement. This is because of the conditions during and after polymerization of the composite materials within the very limited space of a root canal. Identifying regions specifically prone to become weak links, and conditions fostering failure near root dentine are a main challenge. Improving treatment requires an improved understanding of the process involved. This is needed to be able to create sufficiently bonded restorations after root canal treatment that can protect the root canal from reinfection by biofilms. Within the framework of the research unit InterDent, we will investigate polymerization induced stresses of composites placed inside root canal cavities. Our interests are in how deformations either lead to delaminations of the interzone between composite and root canal dentine versus when they are frozen in the material and remain as residual stresses in the filling material. Specifically, if good bonding is achieved the stress state most likely will change during later use of the restored tooth. The interzone between composite and root canal dentine comprises the interfaces between dentine and adhesive as well as between dentine and composite. In cases of post placement, the interface between post and composite is additionally included. Analyses of the temporal polymerization and shrinkage strain/stress dynamics using standardized root canal samples will sequentially increase in complexity during this project. Ultimately, we will identify the most relevant parameters for achieving a tight seal of the root canal. By combining different optical methods with X-ray radiography and tomography and mechanical testing, we will map the structural dynamics aiming at identifying the most relevant parameters affecting the risk of failure of composite based core buildups following root canal treatment. Aspects of material aging will be integrated and its effects on the described interzone will be evaluated.
DFG Programme
Research Units
