Do different time intervals in placement of restorative materials over calcium silicate cements, affect interface microhardness of different restorative materials?

Objectives: The type of materials and application time of final restorations on calcium silicate cements (CSCs) are important factors which influence the interfacial properties. The aim of this study was to investigate the effect of different placement time of RMGI (Resin Modified Glass Ionomer), composite resin and amalgam over different CSCs on the surface microhardness of these restorative materials.Methods: Each CSCs material (Biodentine, MTA, CEM cement) was mixed and carried into a hole (6mm diameter ×4 mm thickness) in the center of 270 molds (n=90 /each CSC). Then these molds were randomly divided into three main experimental groups (n=30) in regard of restorative materials (Amalgam, RMGI, Composite) that were placed in the other molds with the same hole size to make restorative materials and CSCs in contact together. Afterwards, each experimental group was divided into three subgroups according to the time interval of restoration placement that was immediately, after 24h and after 72h (n=10). Two molds were separated from each other after one week storage in incubator with 100% humidity in 37 °C, in order to evaluate the Vickers microhardness of restorative materials in CSC-restorative material interface. Statistical analysis included two-way Anova followed by Post hoc Dunnett T3 in cases with lack of homogeneity and Tukey HSD in cases with homogeneity.(p=0.05)Results: The microhardness of all restorative materials was neither significantly influenced by the CSCs materials (p>0.05) nor by the timing of final restoration (p>0.05) except in RMGI in immediate contact with CEM cement. (p<0.001)Conclusion: Restorative materials hardness in interface with studied CSCs may not affect. This in vitro study found no evidence against immediate definitive restoration over CSCs.

New Bioactive Calcium Silicate Cement Mineral Trioxide Aggregate Repair High Plasticity (MTA HP)—A Systematic Review

Bioactive calcium silicate cement Mineral Trioxide Aggregate (MTA) has been used for years as a gold standard in intravital pulp treatment and specialist endodontic procedures. Owing to flaws of the material, the manufacturers have been trying to enhance and produce materials showing improved physical, chemical and biological parameters. One of the new calcium-silicate cements based on mineral trioxide aggregate, however without some flaws exhibited by the cement, is Mineral Trioxide Aggregate Repair High Plasticity (MTA HP). The aim of the present paper was a systematic literature review concerning the MTA HP material used nowadays in dentistry, as a review of its specific features. The present paper is the first article providing a systematic literature review on MTA HP. The aim of the present article is the better understanding of MTA HP properties, which can aid the decision-making process in endodontic treatment.

Biomaterial and Biofilm Interactions with the Pulp-Dentin Complex-on-a-Chip

Calcium silicate cements (CSCs) are the choice materials for vital pulp therapy because of their bioactive properties, promotion of pulp repair, and dentin bridge formation. Despite the significant progress made in understanding CSCs’ mechanisms of action, the key events that characterize the early interplay between CSC-dentin-pulp are still poorly understood. To address this gap, a microfluidic device, the “tooth-on-a-chip,” which was developed to emulate the biomaterial-dentin-pulp interface, was used to test 1) the effect of CSCs (ProRoot, Biodentine, and TheraCal) on the viability and proliferation of human dental pulp stem cells, 2) variations of pH, and 3) release within the pulp chamber of transforming growth factor–β (TGFβ) as a surrogate of the bioactive dentin matrix molecules. ProRoot significantly increased the extraction of TGFβ ( P < 0.05) within 24 to 72 h and, along with Biodentine, induced higher cell proliferation ( P > 0.05), while TheraCal decreased cell viability and provoked atypical changes in cell morphology. No correlation between TGFβ levels and pH was observed. Further, we established a biofilm of Streptococcus mutans on-chip to model the biomaterial-biofilm-dentin interface and conducted a live and dead assay to test the antimicrobial capability of ProRoot in real time. In conclusion, the device allows for direct characterization of the interaction of bioactive dental materials with the dentin-pulp complex on a model of restored tooth while enabling assessment of antibiofilm properties at the interface in real time that was previously unattainable.

Calcium Silicate Cements vs. Epoxy Resin Based Cements: Narrative Review

In recent years, calcium silicate cements have been introduced. The purpose of this study is to analyze the main differences between calcium silicate-based cements and epoxy resin-based cements, analyzing the scientific literature of the last year to highlight the main advantages for predictable clinical use. Data collected from the included studies were used in order to analyze different features: chemical-physical properties, cytotoxicity and cell migration, inflammatory response, mineralizing and osteogenic activity, ion release and the filling efficiency of root canals. The calcium silicate cements analyzed in these studies showed good biological and mechanical properties compared to conventional resin-based cements, resulting in better biocompatibility and less cytotoxicity; long-term studies are needed, but these cements have ideal characteristics to allow efficient filling of root canals.