Dpto. Odontología

Objective: This study aimed to develop polymer-based barrier membranes based on poly(butylene-adipate-co-terephthalate) (PBAT) with the addition of 1,3,5-triacriloilhexahydro-1,3,5- triazine (TAT). Materials and Methods: Polymeric solutions were used to produce membranes with 5 wt% and 10 wt% of TAT by solvent casting. Membranes without the addition of TAT were used as controls. The membranes were chemically characterized by Fourier transform infrared spectroscopy (FTIR) and thermogravimetry (TGA); surface properties were assessed by profilometry and contact angle; the mechanical behavior was evaluated by a tensile test, and the biological properties were assessed by direct–indirect cell viability and antibacterial activity by S. mutans and S. aureus colonyforming units. Results: TAT was detected in the FTIR and TGA analyses and modified the top surface of the membranes, increasing their roughness and wetness in both concentrations compared to the control group (p < 0.05). The addition of TAT, regardless of concentration, reduced the tensile strength and increased membrane stiffness (p < 0.05). The cell viability of 5 wt% TAT and 10 wt% TAT was 86.37% and 82.36%, respectively. All tested concentrations reduced the formation of biofilm on the membranes when compared to the control. Conclusion: The addition of TAT successfully resulted in the antimicrobial ability of PBAT-based barrier membranes, while it maintained acceptable levels of cell viability in membranes with adequate handling and surface properties.

The aim of this in vitro study was to investigate the compressive strength and the bulk porosity of a bidirectional (bFRC) and an experimental bidirectional spiral winding reinforced fiber composite (bswFRC). Cylindrical-shape specimens were prepared for each material group and processed for the evaluation of compressive strength after different storage conditions (dry, 1 and 3 months) in distilled water at 37 C. The specimens were also assessed for the degree of bulk porosity through X-ray tomography. A scanning electron microscope (SEM) was used to determine the fracture mode after a compressive strength test. Data were statistically analyzed using Two-Way Analysis of Variance (ANOVA). A significantly lower compressive strength was obtained in dry conditions, and after 1 month of water immersion, with the specimens created with bFRC compared to those made with bswFRC (p < 0.05). No significant difference (p > 0.05) was found between the two groups after 3 months of water immersion. However, the presence of water jeopardized significantly the compressive strength of bswFRC after water storage. The type of fracture was clearly different between the two groups; bswFRC showed a brutal fracture, whilst bFRC demonstrated a shear fracture. The bswFRC demonstrated higher pore volume density than bFRC. In conclusion, bswFRC is characterized by greater compressive strength compared to bFRC in dry conditions, but water-aging can significantly decrease the mechanical properties of such an innovative FRC. Therefore, both the novel bidirectional spiral winding reinforced fiber composites (bswFRC) and the bidirectional fiber reinforced composites (bFRC) might represent suitable materials for the production of post-and-core systems via CAD/CAM technology. These findings suggest that both FRC materials have the potential to strengthen the endodontically treated teeth.

This narrative review will focus on a number of contemporary considerations relating to the restoration of root filled teeth and future directions for research. Clinicians are now more than ever, aware of the interdependence of the endodontic and restorative aspects of managing root filled teeth, and how these aspects of treatment are fundamental to obtaining the best long-term survival. To obtain the optimal outcomes for patients, clinicians carrying out endodontic treatment should have a vested interest in the restorative phase of the treatment process, as well as an appreciation for the structural and biomechanical effects of endodontic-restorative procedures on restoration and tooth longevity. Furthermore, the currently available research, largely lacks appreciation of occlusal factors in the longevity of root filled teeth, despite surrogate outcomes demonstrating the considerable influence this variable has. Controversies regarding the clinical relevance of minimally invasive endodontic and restorative concepts are largely unanswered with respect to clinical data, and it is therefore, all too easy to dismiss these ideas due to the lack of scientific evidence. However, conceptually, minimally invasive endodontic-restorative philosophies appear to be valid, and therefore, in the pursuit of improved clinical outcomes, it is important that the efficacies of these treatment protocols are determined. Alongside an increased awareness of the preservation of tooth structure, developments in adhesive bonding, ceramic materials and the inevitable integration of digital dentistry, there is also a need to evaluate the efficacy of new treatment philosophies and techniques with well-designed prospective clinical studies.

The promotion of biologically based treatment strategies in restorative dentistry is of paramount importance, as invasive treatments should be avoided to maintain the tooth’s vitality. This study aimed to assess the biocompatibility of commercially available bioactive materials that can be used for dental pulp capping. The study was performed with a monocyte/macrophage peripheral blood SC cell line (ATCC CRL-9855) on the following six specific bioactive materials: ProRoot MTA (Dentsply Sirona), MTA Angelus (Angelus), Biodentine (Septodont), TheraCal LC (Bisco), ACTIVA BioACTIVE (Pulpdent) and Predicta Bioactive Bulk (Parkell). The cytotoxicity of the investigated agents was measured using a resazurin-based cell viability assay, while the genotoxicity was evaluated using an alkaline comet assay. Additionally, flow cytometry (FC) apoptosis detection was conducted with a FITC (fluorescein isothiocyanate) Annexin V Apoptosis Detection Kit I. FC cell-cycle arrest assessment was carried out with propidium iodide staining. The results of this study showed no significant cytotoxicity and genotoxicity (p > 0.05) in ProRoot MTA, MTA Angelus, Biodentine, ACTIVA BioACTIVE and Predicta Bioactive. Conversely, TheraCal LC presented a significant decrease (p < 0.001). In conclusion, due to excellent biocompatibility and low cytotoxicity, MTA, Biodentine, ACTIVA BioACTIVE and Predicta Bioactive may be suitable for pulp capping treatments. On the other hand, due to the high cytotoxicity of TheraCal LC, its use should be avoided in vital pulp therapies.

The evaluation of the porosities within the interface of root canals obturated with endodontics materials is extremely important for the long-term success of endodontic treatments. The aim of this study was to compare initial and long-term volume of pores (total, open, closed) and porosity (total, regional) of three bioactive endodontic sealers: GuttaFlow Bioseal, Total Fill BC Sealer, and Bio- Root RCS. Root canals were obturated with three “bioactive” sealers using the single-cone technique. The volume of open and closed pores and porosity were calculated using a micro-computed tomography (MCT) method. The measurements were performed after 7 days (initial) and after 6 months (long-term) of incubation. Statistical significance was considered at p < 0.05. The total volume of pores remained unchanged after the 6-month storage. GuttaFlow Bioseal exhibited significantly higher long-term volume in open pores than Total Fill BC Sealer. The total porosity in all the tested sealers presented no statistically significant change after the 6-month storage, except for BioRoot RCS. The total porosity values of this latter material significantly increased after long-term incubation, especially in the apical region. In conclusion, the use of bioactive sealers with excessive tendency to create porosities both in shorth- and long-term periods of storage may compromise the long-term success of endodontic treatments.

The study investigated allogenic pulp transplantation as an innovative method of regenerative endodontic therapy. Three patients were selected for the endodontic treatment of single-root teeth, who also had a son/daughter with deciduous teeth or third molars scheduled for extraction. Receptor teeth were endodontically instrumented and irrigated using a tri-antibiotic solution. During the transplant procedures, the teeth from the son/daughter were extracted, sectioned, and the pulp was carefully removed. The harvested pulp from the donor was inserted into the root canal of the host tooth (father/mother), followed by direct pulp capping and resin composite restoration. The teeth were followed-up with for 2 years and were surveyed with computed tomography, the electric pulp vitality test, and Doppler ultrasound examination. At the 6-month follow-up, positive pulp vitality and the formation of periapical lesions were verified in cases 1 and 2. Case 3 showed remarkable periapical radiolucency before transplantation, but after 1 year, such lesions disappeared and there was positive vitality. All teeth were revascularized as determined by Doppler imaging after 2 years with no signs of endodontic/periodontal radiolucency. In conclusion, although this was a case series with only three patients and four teeth treated, it is possible to suppose that this allogenic pulp transplantation protocol could represent a potential strategy for pulp revitalization in specific endodontic cases.