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

Despite the fact that the benefits of implementation of Evidence-Based Dentistry (EBD) into clinical practice is increasingly being highlighted, there are still clear limitations in its implementation into daily dental practice. One potentially important barrier to effective implementation into practice is the perception of EBD as a time-consuming process. The aim of the present study is to increase the familiarity of dental practitioners with the benefits of different time-dependent 'practical' search strategies important to EBD using a clinical question from the field of dental implantology as an example.

Practical Implementation of Evidence-Based Dentistry Into Daily Dental Practice Through a Short Time Dependent Searching Method.

The present work aims at evaluating the potential gains derived from partially replacing calcium in resorbable β-tricalcium phosphate (β-TCP) by two different molar percentages of strontium (5, 10) and zinc (1, 2), concomitantly with a fixed molar percentage (0.5) of manganese. Synthetic granular composite bone filling grafts consisting of doped β-TCP and an alkali-free bioactive glass were prepared and implanted in ~4 mm diameter bone defects drilled in the calvaria of Wistar rats used as animal models. The animals were sacrificed after 9 weeks of implantation and the calvaria was excised. Non-manipulated bone was used as positive control, while empty defects were used as a negative control group. The von Kossa staining revealed an enhanced new bone formation with increasing doping levels, supporting the therapeutic effects exerted by the doping elements. The percentage of newly formed bone was similar when the defects were filled with autologous bone, BG (previous results) or 3TCP2/7BG, which indicates that the latter two are excellent candidates for replacement of autologous bone as bone regeneration material. This finding confirms that doping with suitable doses of therapeutic ions is a good strategy towards transposing the bone graft materials to biomedical applications in humans.

Doping β-TCP as a Strategy for Enhancing the Regenerative Potential of Composite β-TCP-Alkali-Free Bioactive Glass Bone Grafts. Experimental Study in Rats.

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: Oculo-facio-cardio-dental (OFCD) syndrome is a rare pathological condition with an X-linked dominant trait that only occurs in females; no males are born with OFCD syndrome. This syndrome is characterized by congenital cataracts with secondary glaucoma ocular defects, ventricular and atrial septal defects, or mitral valve prolapses. Facial traits are a long narrow face and a high nasal bridge with a bifid nasal tip. Dental anomalies include radiculomegaly, oligodontia, root dilacerations, malocclusion, and delayed eruption. (2) Methods: This clinical report describes a 26-year-old girl who suffers from OFCD syndrome and who was treated with a multidisciplinary approach. The treatment plan included orthodontic treatment, orthognathic surgery, namely LeFort I and a Bilateral Sagittal Split Osteotomy, and occlusal rehabilitation with implants. (3) Discussion: Early diagnosis and multidisciplinary treatment of orthodontic, orthognathic surgery and occlusal rehabilitation with implants make it possible to maintain tooth function and improve aesthetics with good prognoses for success. In this paper, we report a case of a female patient with OFCD syndrome, who was referred for orthodontic treatment and occlusal rehabilitation and treated with a multidisciplinary approach.

Oculo-Facio-Cardio-Dental Syndrome: A Case Report about a Rare Pathological Condition.

(1) Background: When pulp exposure occurs, reparative dentinogenesis can be induced by direct pulp capping to maintain the vitality and function of the tissue. The aim of this work was to assess the cytotoxicity and bioactivity of three different direct pulp capping materials, calcium hydroxide (Life), mineral trioxide aggregate (WhiteProRootMTA) and calcium silicate (Biodentine), in an odontoblast-like mouse cell line (MDPC-23). (2) Methods: Metabolic activity was assessed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide test (MTT)assay, viability by the sulforhodamine B (SRB) assay, and the type of death and cell cycle analysis by flow cytometry. Alkaline phosphatase was evaluated by polymerase chain reaction (PCR), and dentin sialoprotein expression was assessed by immunocytochemistry. Mineralization was determined by the Alizarin Red S colorimetric assay and quantified by spectrophotometry. (3) Results: Life induced a decrease in metabolic activity and viability, which is associated with an increase cell death. WhiteProRootMTA and Biodentine™ induced similar effects in cytotoxicity assays, with an increase in the expression of dentin sialoprotein (DSP) and formation of mineralized deposits, especially with Biodentine™. (4) Conclusions: The results of WhiteProRootMTA confirm its indication for these therapies, justifying its recognition as the "gold standard". Biodentine™ may be an alternative, since they promote the same cellular response that mineral trioxide aggregate (MTA) does.

Biodentine Boosts, WhiteProRootMTA Increases and Life Suppresses Odontoblast Activity.

(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.

(1) Background: Bisphosphonate-related osteonecrosis of the jaw (BRONJ) is one of the most often seen side effects in patients treated with nitrogen-containing bisphosphonates (BPs), a post-surgical non-healing wound condition. Since calcium phosphate (CP) compounds are able to adsorb zoledronate (ZOL) when used as a drug delivery vehicle, we aimed to verify if these ceramics might have a potential protective effect for soft tissues surrounding surgical osseous wounds. (2) Methods: The chemical reaction between ZOL and CP compounds was evaluated through ultraviolet-visible spectroscopy and elemental analysis. A primary culture of human gingival fibroblasts (HGF) was established as a model to evaluate the cytotoxicity of the association of ZOL (5-500 μM) and of ZOL/biphasic calcium phosphates (BCP). Metabolic activity, cell viability, types of cell death, the cell cycle through, and the migration ability of human gingival fibroblasts were evaluated. (3) Results: ZOL was adsorbed by biphasic calcium phosphate compounds in an aqueous solution. The HGF were sensitive to ZOL toxicity; nevertheless, ZOL/BCP showed a significant protective effect regarding metabolic activity, cell viability, and cell migration. (4) Conclusions: BCP interaction with ZOL reduces or abolishes its toxicity in HGF. This finding represents a potential solution for BRONJ in the case of patients undergoing therapy with ZOL.

Synthetic Calcium Phosphate Ceramics as a Potential Treatment for Bisphosphonate-Related Osteonecrosis of the Jaw.

(1) Background: Recently, tricalcium silicate cements, such as Biodentine™, have emerged. This biomaterial has a calcium hydroxide base and characteristics like mineral aggregate trioxide cements, but has tightening times that are substantially more suitable for their application and other clinical advantages. (2) Methods: A retrospective clinical study was conducted with 20 patients, which included a clinical evaluation of the presence or absence of pulp inflammation compatible symptoms, radiographic evaluation of the periapical tissues, and structural alterations of the coronary restoration that supports pulp capping therapies with Biodentine™ and WhiteProRootMTA. (3) Results: This clinical study revealed similar success rates between mineral trioxide cement and tricalcium silicates cements at 6 months, with 100% and 95% success rates, respectively. There were no statistically significant differences between both biomaterials and between these and the various clinical circumstances, namely the absolute isolation of the operating field, exposure size, the aetiology of exposure, and even the type of restorative material used. (4) Conclusions: Biodentine™ demonstrated a therapeutic effect on the formation of a dentin bridge accompanied by slight inflammatory signs, with a high clinical success rate, indicating the possibility of its effective and safe use in dental pulp direct capping in humans, similar to the gold standard material.

Article	Year
Practical Implementation of Evidence-Based Dentistry Into Daily Dental Practice Through a Short Time Dependent Searching Method. The journal of evidence-based dental practice\| PubMed ID: 27132551	2016
Doping β-TCP as a Strategy for Enhancing the Regenerative Potential of Composite β-TCP-Alkali-Free Bioactive Glass Bone Grafts. Experimental Study in Rats. Materials (Basel, Switzerland)\| PubMed ID: 30577440	2018
10-MDP Based Dental Adhesives: Adhesive Interface Characterization and Adhesive Stability-A Systematic Review. Materials (Basel, Switzerland)\| PubMed ID: 30866488	2019
Oculo-Facio-Cardio-Dental Syndrome: A Case Report about a Rare Pathological Condition. International journal of environmental research and public health\| PubMed ID: 30875852	2019
Biodentine Boosts, WhiteProRootMTA Increases and Life Suppresses Odontoblast Activity. Materials (Basel, Switzerland)\| PubMed ID: 30978943	2019
Once Resin Composites and Dental Sealants Release Bisphenol-A, How Might This Affect Our Clinical Management?-A Systematic Review. International journal of environmental research and public health\| PubMed ID: 31075949	2019
Synthetic Calcium Phosphate Ceramics as a Potential Treatment for Bisphosphonate-Related Osteonecrosis of the Jaw. Materials (Basel, Switzerland)\| PubMed ID: 31174333	2019
Direct Pulp Capping: Which is the Most Effective Biomaterial? A Retrospective Clinical Study. Materials (Basel, Switzerland)\| PubMed ID: 31623190	2019

Eunice Carrilho

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