accessing-the-cytotoxicity-and-cell-response-to-biomaterials

Accessing the Cytotoxicity and Cell Response to Biomaterials

Biomaterials contact directly or indirectly with the human tissues, making it important to evaluate its cytotoxicity. This evaluation can be performed by ...

University of Coimbra, Coimbra, Portugal

Clinical Academic Center of Coimbra, CACC, Portugal

The incorporation of functional monomers in dental adhesive systems promotes chemical interaction with dental substrates, resulting in higher adhesion forces when compared to micromechanical adhesion only. The 10-MDP monomer, whose chemical structure allows for a polar behavior which is favorable to adhesion, also promotes the protection of collagen fibers through the formation of MDP-calcium salts. This systematic review aimed to characterize the interface created by 10-MDP containing adhesive systems through an evaluation of the following parameters: Formation of nano-layered structures, capacity to produce an acid-base resistant zone, and adhesion stability. The research was conducted using PubMed, Cochrane Library, Web of Science and Embase, limited to English, Spanish, and Portuguese articles. The research was done according to the PICO strategy. The 10-MDP monomer has the capacity to produce an acid-base resistant zone on the adhesive interface, which increases the response to acid-base challenges. The adhesion established by these systems is stable over time. To have the best of these adhesive solutions, a scrubbing technique must be used to apply the adhesive system on dental substrates, in order to improve monomers infiltration and to create a stable bond. Time must be given for the solution to infiltrate, hybridize and form the MDP-Ca, improving adhesive stability.

10-MDP Based Dental Adhesives: Adhesive Interface Characterization and Adhesive Stability-A Systematic Review.

(1) Background: Bisphenol A (BPA) based dental resins are commonly used in preventive and reparative dentistry. Since some monomers may remain unpolymerized in the application of dental resin, they dissolve in the saliva. (2) Methods: The literature search was carried out in Pubmed, Cochrane and Embase databases. Randomized controlled trials, cohort studies and case-control studies that evaluated BPA levels in human urine, saliva and/or blood were included. (3) Results: The initial search had 5111 results. A total of 20 studies were included in the systematic review. Most studies showed an increase of the levels of bisphenol A 1 h after treatments with composite resins and dental sealants. One week after treatments the levels were decreased. (4) Conclusions: Some clinical precautions should be taken to decrease the release of BPA, namely the use of rubber dam, the immediate polishing of all resins used, or the use of glycerin gel to avoid non-polymerization of the last resin layer, and mouthwash after treatment. Another preventive measure in addition to the above-mentioned is the use of the smallest possible number of restorations or sealants, a maximum of four per appointment. These measures are even more important in children, adolescents and pregnant women.

Once Resin Composites and Dental Sealants Release Bisphenol-A, How Might This Affect Our Clinical Management?-A Systematic Review.

The aim of this study was to evaluate the cytotoxic effects of an enzymatic mouthwash and of a chlorhexidine mouthwash on human gingival fibroblasts. The metabolic activity of the fibroblasts exposed to each mouthwash was assessed by the MTT assay and the protein content was assessed by the SRB assay. The flow cytometry was used to evaluate the cell cycle and the types of cell death. The oxidative status was evaluated through the DCF and the DHE probes and the intracellular GSH concentration and the mitochondrial membrane potential through JC-1. The cytotoxicity of both mouthwashes was found to be dependent on the exposure time and on the concentration. However, the cytotoxicity of the enzymatic mouthwash was found to be lower than that of the chlorhexidine mouthwash. A trend towards increased oxidative stress was observed for both mouthwashes. After exposing the fibroblasts to the mouthwashes, a G2/M phase block was observed and cell death occurred predominantly by necrosis. The effects of chlorhexidine on fibroblasts were identified at lower concentrations than those used in clinical practice. Therefore, the use of chlorhexidine as an antiseptic in surgical and postoperative situations should be limited. In order to clarify the clinical significance of the enzymatic mouthwash cytotoxicity new clinical studies will be necessary.

Cytotoxic effects of a chlorhexidine mouthwash and of an enzymatic mouthwash on human gingival fibroblasts.

The increase in the use of electronic cigarettes (e-cigs) in young people and the lack of knowledge of the health effects of smoking in the short and long term are worrying. Although the oral cavity is the first to interact directly with the e-cig aerosol, studies on potential oral cavity lesions are still limited and there is some controversy about safety.

Ana Sofia Coelho

University of Coimbra, Coimbra, Portugal

Accessing the Cytotoxicity and Cell Response to Biomaterials