PLGA+HA/βTCP scaffold incorporating simvastatin: A promising biomaterial for bone tissue engineering Mariane Beatriz Sordi, Ariadne Cristiane Cabral da Cruz, Águedo Aragones, Mabel Mariela Rodríguez Cordeiro, Ricardo de Souza Magini Journal of Oral Implantology, 2021 The aim of this study was to synthesize, characterize, and evaluate degradation and biocompatibility of poly(lactic-co-glycolic acid) + hydroxyapatite/β-tricalcium phosphate (PLGA+HA/βTCP) scaffolds incorporating simvastatin (SIM) to verify if this biomaterial might be promising for bone tissue engineering. Samples were obtained by the solvent evaporation technique. Biphasic ceramic particles (70% HA, 30% βTCP) were added to PLGA in a ratio of 1:1. Samples with SIM received 1% (m/m) of this medication. Scaffolds were synthesized in a cylindric shape and sterilized by ethylene oxide. For degradation analysis, samples were immersed in phosphate-buffered saline at 37°C under constant stirring for 7, 14, 21, and 28 days. Nondegraded samples were taken as reference. Mass variation, scanning electron microscopy, porosity analysis, Fourier transform infrared spectroscopy, differential scanning calorimetry, and thermogravimetry were performed to evaluate physico-chemical properties. Wettability and cytotoxicity tests were conducted to evaluate the biocompatibility. Microscopic images revealed the presence of macro-, meso-, and micropores in the polymer structure with HA/βTCP particles homogeneously dispersed. Chemical and thermal analyses presented similar results for both PLGA+HA/βTCP and PLGA+HA/βTCP+SIM. The incorporation of simvastatin improved the hydrophilicity of scaffolds. Additionally, PLGA+HA/βTCP and PLGA+HA/βTCP+SIM scaffolds were biocompatible for osteoblasts and mesenchymal stem cells. In summary, PLGA+HA/βTCP scaffolds incorporating simvastatin presented adequate structural, chemical, thermal, and biological properties for bone tissue engineering.
Correlation between bond strength to dentin and sealers penetration by push-out test and CLSM analysis Maybell Tedesco, Marcelo Carvalho Chain, Wilson Tadeu Felippe, Ana Maria Hecke Alves, Lucas da Fonseca Roberti Garcia, et al. Brazilian Dental Journal, 2019 This study correlated the bond strength (BS) and dentin penetration of different sealers by push-out test and Confocal Laser Scanning Microscopy (CLSM) analysis. Forty-five root canals were prepared according to the crown-down technique and filled with gutta-percha associated to the following sealers (n=15): Endofill, AH Plus and MTA Fillapex. Five canals of each group were filled with the sealers added with 0.1% Rhodamine B dye. Next, the specimens were transversely sectioned and submitted to the push-out test (n=10) and CLSM analysis (n=5). The BS data showed the following means (MPa) and standard deviation: AH Plus (4.17±1.86); MTA Fillapex (3.13±1.96) and Endofill (2.10±1.03). Statistical analysis (two-way ANOVA, α=0.05) showed significant difference among sealers (p<0.001) and root canal thirds (p<0.001). The BS results of Endofill and MTA Fillapex were statistically similar (p>0.05), however, they were statistically different from AH Plus (p<0.001). The regional analysis of BS showed similarity between middle and apical thirds (p>0.05), and both were different from coronal portion (p<0.001). CLSM analysis verified tags formation in all groups and higher penetration of the specimens filled with AH Plus (p<0.05). The Kendall test (correlation between BS to dentin and sealer penetration into dentinal tubules) and the Pearson test (between failures pattern and sealer penetration into dentinal tubules) did not show correlation between the variables evaluated for all the tested sealers (p>0.05). AH Plus group had higher BS to dentin, and deeper tags formation than the other sealers. There was no significant correlation between BS and intratubular penetration of the tested sealers.
Inhibition of cancer stem cells promoted by Pimozide Jussara Maria Gonçalves, Carolina Amália Barcellos Silva, Elena Riet Correa Rivero, Mabel Mariela Rodríguez Cordeiro Clinical and Experimental Pharmacology and Physiology, 2019 Over the past years, studies have described that users of antipsychotics are less likely to develop cancer than the population in general due to cytotoxic properties of this class of drugs on cancer cells. For this reason, Pimozide has been widely studied as a potential anticancer treatment, and satisfactory results in melanoma, central nervous system tumours, osteosarcoma, neuroblastoma, myeloproliferative neoplasms, breast, lung, prostate, ovarian, colorectal, pancreatic, and hepatocellular carcinoma have been showed. Moreover, advantages as clinical use approved by the Food and Drug Administration (FDA), high clinical safety, low side effects, and reasonable price have stimulated the treatment with Pimozide instead of other agents. The action mechanism remains unclear, but three vias associated to cancer stem cell (CSC) hypothesis show that Pimozide: (a) blocks CSC features, as epithelial‐to‐mesenchymal transition (EMT), through inhibition of Wnt‐β/catenin signalling; (b) acts as an inhibitor of signal transducer and activator of transcription (STAT‐3 and 5), pathway which is activated and up‐regulated in CSCs; (c) inhibits ubiquitine specific protease (USP1) and WD repeat‐containing protein 48 (WDR48), that are proteins responsible to inhibit the differentiation and to maintain the cell in an undifferentiated state. Based on this perspective, the aim of this manuscript is to review the antineoplastic role of Pimozide during tumorigenesis and its potential to revert the process of undifferentiation and proliferation of CSC through different vias.
Retrospective study of 124 cases of salivary gland tumors and literature review A Reinheimer, DSC Vieira, MMR Cordeiro, ERC Rivero Journal of Clinical and Experimental Dentistry, 2019 Background Salivary gland tumors are a rare and morphologically diverse group of lesions and their frequency is still unknown in several parts of the world. The knowledge of its population characteristics contributes to a better understanding of its etiopathogenesis. Objectives: This study investigated the frequency of salivary gland tumors in a region of southern Brazil and compared these data in a literature review. Material and Methods A retrospective study was conducted of salivary gland tumors diagnosed at two pathology centers from 1995 to 2016. Patient age and gender, tumor site and frequency, histopathological diagnosis, and symptomatology were evaluated. Chi-squared tests were used to assess the associations between variables. To compare our data, we also conducted a literature review of publications in the PubMed and LILACS databases of retrospective studies of salivary gland tumors. Results A total of 124 salivary gland tumor cases was identified, 81 (65.3%) of which were classified as benign and 43 (34.6%) as malignant. Most tumors occurred in the parotid gland (57.2%). Pleomorphic adenoma was the most common tumor (59.6%), followed by adenocarcinoma not otherwise specified (8.8%). The tumors occurred more often in women (54.8%) than in men (45.2%). Malignant tumors were associated with pain in 31.4% of cases (p<0.05). The literature review included 35 articles from different countries. Women were most affected, with a mean age of 41.7 years. The most common benign tumor was pleomorphic adenoma (48.2%) and the most common malignant tumor was mucoepidermoid carcinoma (8.7%). Conclusions The results of the present study showed that salivary gland tumors are rare. The parotid gland is the most common location and pleomorphic adenoma are the most frequent lesions. The malignant tumors presented as several histological types and the incidence was variable globally. Key words:Salivary gland neoplasms, salivary gland diseases, oral surgery, epidemiology.
Expression of Cancer Stem Cell Biomarkers in Human Head and Neck Carcinomas: a Systematic Review Raissa Borges Curtarelli, Jussara Maria Gonçalves, Luciane Geanini Pena dos Santos, Maria Gorete Savi, Jacques Eduardo Nör, et al. Stem Cell Reviews and Reports, 2018 Malignant neoplasms may be composed of several cell groups, including cancer stem cells (CSC). These cells have been related with the capacity of metastasis, relapse and resistance to multiple drugs during chemotherapy. This study aims to identify CSC biomarkers and their expression pattern in human head and neck carcinomas. This study was conducted following the PRISMA checklist. The search for articles was carried out in five databases (PubMed, Scopus, Web of Science, Lilacs and Scielo). The articles found were selected in two phases: 1) reading the titles and / or abstract and 2) reading the full text. At the end, the selected articles were evaluated by QUADAS-2. Most studies evaluated oral neoplastic tissues and, as a control, samples of normal local mucosa. All studies performed immunohistochemistry as a method of immunolocalization and some also applied immunofluorescence. The most commonly used biomarker was CD44. However, other such as Sox2, Oct4, Nestin, Nanog, BMI1, ALDH1, CD133 and CD166 were also found. Several biomarkers were (ALDH1, Sox2, Oct4, ABCB5, AGR2 and TAZ) correlated with clinical characteristics of the tumor, such as staging, tumor size and lymph node metastasis. These data reinforce the CSC theory and favor the use of these biomarkers as possible determinants of prognosis.
Efficacy of a single session protocol for endodontic treatment in primary teeth: in vivo study T. C. Triches, G. S. Zimmermann, S. F. T. de Freitas, M. Ximenes, R. S. Vieira, et al. European Archives of Paediatric Dentistry, 2018 AimsTo determine the efficacy of a single session protocol (SSP) in the reduction of septic content of primary teeth root canals and identify the persistence of bacterial species associated with unsuccessful treatment.MethodsPrimary teeth root canals (16) with pulp necrosis and peri-radicular lesions were treated. Samples were collected at baseline (T1), and after chemo-mechanical preparation, before filling (T2). Identification of the microorganisms was determined using checkerboard DNA–DNA hybridisation. Statistical analysis: Wilcoxon test was applied for comparison of mean number of species, proportion and mean count of each species between the evaluation times.ResultsSignificant reductions were found in the mean number of bacteria species between T1 and T2 (p < 0.05), but not for the reduction in proportion (p > 0.05). There was a reduction (6.0–4.6) of the mean number of species associated with failure, without statistical significance.ConclusionThe SSP was capable of significantly reducing the septic content, even though, many of the bacteria associated with failure persisted at the time of root canal filling.
Teaching and learning regarding the dentist-pediatric patient relationship: A qualitative study Bianca Zimmermann Santos Pesquisa Brasileira Em Odontopediatria E Clinica Integrada, 2018 Objective: To investigate the perceptions of dental students on the learning process regarding the dentist-pediatric patient relationship. Material and Methods: A qualitative study with an exploratory approach was conducted involving semi-structured interviews with sixteen dental undergraduate students randomly selected from the thirty-two students in the last semester of the dentistry course. The transcribed interviews were submitted to content analysis. Results: The sample was composed of nine female (56.3%) and seven male (43.7%) students (median age: 23 years). The factors perceived as most influential with regard to learning the dentist-pediatric patient relationship were observations of professors, other dentists or colleagues and the regular practice of dental procedures. While half of the participants considered lectures on the subject satisfactory, the other half reported a need for more instruction on how to deal with specific clinical situations. Most of the participants would like to have learned more about the dentist-pediatric patient relationship. Conclusion: The majority of students recognized that the teaching and learning process regarding the dentist-pediatric patient relationship is not easy. They reported having little counseling on the how to develop this relationship. The students suggested that the dentist-patient relationship should be addressed more during the course through the inclusion of lectures or classes on this issue as well as the demonstration of specific clinical situations.
Crown discoloration promoted by materials used in regenerative endodontic procedures and effect of dental bleaching: Spectrophotometric analysis Luciane Geanini Pena dos SANTOS, Wilson Tadeu FELIPPE, Beatriz Dulcineia Mendes de SOUZA, Andrea Cristina KONRATH, Mabel Mariela Rodríguez CORDEIRO, et al. Journal of Applied Oral Science, 2017 Regenerative endodontic procedure (REP) has been proposed as a new approach to treat immature permanent teeth. However, materials used in REP for root canal disinfection or cervical sealing may induce tooth discoloration. Objectives To assess tooth crown’s color after intracanal treatment with triple antibiotic paste (TAP) or calcium hydroxide (CH); cervical sealing with glass ionomer cement (GIC) or mineral trioxide aggregate (MTA); and bleaching with carbamide peroxide. Material and Methods After pulp removal and color spectrophotometer measurement, 50 bovine incisors were divided into 4 experimental groups and one control (untreated). Experiments were performed in phases (Ph). Ph1: TAP (ciprofloxacin, metronidazole, minocycline), TAPM (ciprofloxacin, metronidazole, amoxicillin), DAP (ciprofloxacin, metronidazole), or CH treatment groups. After 1 and 3 days (d); 1, 2, 3 weeks (w); and 1, 2, 3 and 4 months (m), color was measured and medications were removed. Ph2: GIC or MTA cervical sealing, each using half of the specimens from each group. Color was assessed after 1d, 3d; 1w, 2w, 3w; 1m and 2m. Ph3: Two bleaching sessions, each followed by color measurement. Data were analyzed with ANOVA and post-hoc Holm-Sidak method. Results Ph1: Specimens of TAP group presented higher color alteration (ΔE) mean than those of TAPM group. No significant difference was found among TAP or TAPM and CH, DAP or Control groups. Ph2: cervical sealing materials showed no influence on color alteration. Ph3: Different ΔE means (from different groups), prior to bleaching, became equivalent after one bleaching session. Conclusions TAP induces higher color alteration than TAPM; color alteration increases over time; cervical sealing material has no influence on color alteration; and, dental bleaching was able to recover, at least partially, the tooth crown’s color.
