RESUMEN
The purpose of this study is to outline relevant elements regarding the biochemical interactions between prosthetic materials used for obtaining implant-supported restorations and the oral environment. Implant-supported prostheses have seen unprecedented development in recent years, benefiting from the emergence of both new prosthetic materials (with increased biocompatibility and very good mechanical behavior), and computerized manufacturing technologies, which offer predictability, accuracy, and reproducibility. On the other hand, the quality of conventional materials for obtaining implant-supported prostheses is acknowledged, as they have already proven their clinical performance. The properties of PMMA (poly (methyl methacrylate))-which is a representative interim material frequently used in prosthodontics-and of PEEK (polyether ether ketone)-a biomaterial which is placed on the border between interim and final prosthetic use-are highlighted in order to illustrate the complex way these materials interact with the oral environment. In regard to definitive prosthetic materials used for obtaining implant-supported prostheses, emphasis is placed on zirconia-based ceramics. Zirconia exhibits several distinctive advantages (excellent aesthetics, good mechanical behavior, biocompatibility), through which its clinical applicability has become increasingly wide. Zirconia's interaction with the oral environment (fibroblasts, osteoblasts, dental pulp cells, macrophages) is presented in a relevant synthesis, thus revealing its good biocompatibility.
RESUMEN
The purpose of this study was to analyze the oxidative stress level and inflammatory status of saliva in the presence of certain materials used for obtaining interim prosthetic restorations. Four types of interim resin materials were investigated: a pressure/heat-cured acrylic resin (Superpont C+B, SpofaDental a.s Czech Republic, /KaVo Kerr Group), a milled resin (Telio CAD polymethyl methacrylate, Ivoclar Vivadent AG, Liechtenstein), a 3D printed resin (NextDent C&B MFH, NextDent by 3D Systems, the Netherlands), and a pressure/heat-cured micro-filled indirect composite resin (SR Chromasit, Ivoclar Vivadent AG, Liechtenstein). The disk-shaped resin samples (30 mm diameter, 2 mm high) were obtained in line with the producers' recommendations. The resulting resin specimens were incubated with saliva samples collected from twenty healthy volunteers. In order to analyze the antioxidant activity of the tested materials, certain salivary parameters were evaluated before and after incubation: uric acid, gamma glutamyl transferase (GGT), oxidative stress responsive kinase-1 (OXSR-1), and total antioxidant capacity (TAC); the salivary levels of tumor necrosis factor (TNFα) and interleukin-6 (IL-6) (inflammatory markers) were measured as well. The obtained results are overall favorable, showing that the tested materials did not cause significant changes in the salivary oxidative stress level and did not influence the inflammatory salivary status.
RESUMEN
BACKGROUND: The oral mucosa protects the underlying tissue from mechanical damage as well as from the entry of exogenous particles and microorganisms. Telocytes (TCs) are disputed stromal cells featuring peculiarly long and thin processes with uneven calibre known as telopodes, which play a number of roles within the interstitia. The present study aimed to test the key markers recommended for discriminating between TCs and false TCs in samples of normal oral mucosa. METHODS: Archived paraffin-embedded oral mucosa samples were tested by means of immunohistochemistry with the following markers: CD34, D2-40, CD31 and CD68. RESULTS: The epithelial expression of CD68, D2-40 and CD34 was detected. Two subsets of CD34-expressing stromal cells were identified, large cells with telopodial processes, presumably of the hematopoietic lineage, and spindle-shaped TC-like cells. Macrophages and TC-like cells within the lamina propria expressed CD68. The lymphatic endothelia were found to express CD31 and D2-40, but not CD34. Sprouting lymphangiogenesis was demonstrated by the lymphatic endothelial tip cells, which were projecting thin processes within the connective stroma. CONCLUSIONS: The epithelial expression of CD68 suggests the professional phagocytic potential of the oral epithelium. Regarding the TCs and TC-like cells in the oral mucosa they could not be accurately distinguished from other possible cell types, neither on morphological basis (evidence of telopodes) nor by use of panels of markers which include CD34.
