Cytotoxic outcomes of orthodontic bands with and without silver solder in different cell lineages.

INTRODUCTION: The safety of orthodontic materials is a matter of high interest. In this study, we aimed to assess the in-vitro cytotoxicity of orthodontic band extracts, with and without silver solder, by comparing the viability outcomes of the HaCat keratinocytes, the fibroblastic cell lineages HGF and MRC-5, and the kidney epithelial Vero cells. METHODS: Sterilized orthodontic bands with and without silver solder joints were added to culture media (6 cm2/mL) and incubated for 24 hours at 37°C under continuous agitation. Subsequently, the cell cultures were exposed to the obtained extracts for 24 hours, and an assay was performed to evaluate the cell viability. Copper strip extracts were used as positive control devices. RESULTS: The extracts from orthodontic bands with silver solder joints significantly reduced the viability of the HaCat, MRC-5, and Vero cell lines, whereas the viability of HGF was not altered by this material. Conversely, the extracts of orthodontic bands without silver solder did not significantly modify the viability index of all evaluated cell lines. CONCLUSIONS: Except for HGF fibroblasts, all tested cell lines showed decreased viability percentages after exposure to extracts of orthodontic bands containing silver solder joints. These data show the relevance of testing the toxicity of orthodontic devices in different cell lines.

Antiviral factors and type I/III interferon expression associated with regulatory factors in the oral epithelial cells from HIV-1-serodiscordant couples.

Individuals who remain HIV-seronegative despite repeated unprotected exposure to the virus are defined as exposed seronegative (ESN) individuals. Innate and adaptive immunity, as well as genetic factors, provide ESNs with important advantages that allow for low infection susceptibility. The majority of HIV-1-infected individuals undergo antiretroviral therapy, which can decrease the level of HIV-1 exposure in ESNs. We analyzed type I interferon (IFN)-related antiviral and regulatory factors in peripheral blood mononuclear cells (PBMCs) and oral epithelial cells from serodiscordant couples. Our findings revealed that ESNs did not induce the expression of antiviral factors (APOBEC-3G, TRIM5-α, SAMDH1, STING, TBk1) or regulatory factors (Trex, Foxo3, Socs3, IL-10) in PBMCs, unlike their HIV-1-infected partners. In contrast, ESNs upregulated APOBEC-3G and type I/III IFNs (IFNs-α,-ß/-λ) in oral mucosal epithelial cells similar to their HIV-infected partners. The serodiscordant groups exhibited an increased expression of type I IFN-induced regulators, such as Trex and Foxo3, in oral epithelial cells. TLR7, TLR8 and TLR9 were expressed in oral epithelial cells of both ESNs and HIV-1-infected subjects. These findings revealed evidence of antiviral factors, type I/III interferon and regulatory factor expression only in the oral mucosal compartment of ESNs, while HIV-1-infected partners systemically and oral mucosal expressed the antiviral profile.

Genotoxicity in oral epithelial cells in children caused by nickel in metal crowns.

The micronucleus (MN) assay evaluates the effects of low doses of genotoxic carcinogens and can detect structural lesions that survive mitotic cycles. The objective of this study was to determine both the genotoxicity of nickel (Ni) in buccal epithelial cells and the urinary excretion of Ni in children with metal crowns. This was a prospective longitudinal study based on 37 patients selected at the Facultad de Odontología de la Universidad Autónoma de Coahuila. MN assays were performed using buccal cells from the 37 patients, and Ni levels were determined from urine samples using inductively coupled plasma mass spectrometry at 1 (basal value), 15, and 45 days following the placement of crowns in each patient. Ni urinary excretion levels increased from 2.12 ± 1.23 to 3.86 ± 2.96 mg Ni/g creatinine (P < 0.05) and the frequency of exposed micronuclei increased from 4.67 ± 0.15 to 6.78 ± 0.167/1000 cells (P < 0.05) between 1 and 45 days post-crown placement. These results suggest that odontological exposure to metal crowns results in genotoxic damage at the cellular level of the oral mucosa and an increase in the urinary excretion of Ni within 45 days of exposure.

Buccal cells DNA extraction to obtain high quality human genomic DNA suitable for polymorphism genotyping by PCR-RFLP and Real-Time PCR.

OBJECTIVE: The aim of this study was to evaluate, by PCR-RFLP and real-time PCR, the yield and quality of genomic DNA collected from buccal cells by mouthwash after different storage times at room temperature. MATERIAL AND METHODS: A group of volunteers was recruited to collect buccal cells using a mouthwash solution. The collected solution was divided into 3 tubes, one tube were used for immediate extraction and the remaining received ethanol and were kept at room temperature for 4 and 8 days followed by dna extraction. The concentration, purity and integrity of the dna were determined using spectrophotometry and electrophoresis. DNA quality differences among the three incubation times were also evaluated for genotyping EGF +61 a/g (rs 4444903) polymorphism by PCR-RFLP and for IRF6 polymorphism (rs 17015215) using real-time PCR. RESULTS: There was no significant difference of dna yield (p=0.75) and purity (p=0.86) among the three different incubation times. DNA obtained from different incubation times presented high-molecular weight. The PCR-RFLP and real time pcr reactions were successfully performed for all DNA samples, even those extracted after 8 days of incubation. All samples genotyped by real-time pcr presented c allele for irf6 gene polymorphism (homozygous: cc; heterozygous: Ct) and the C allele was used as a reference for Ct values. The samples presented the same genotype for the different times in both techniques. CONCLUSION: We demonstrated that the method described herein is simple and low cost, and that DNA can be extracted and pcr amplified after storage in mouthwash solution at room temperature.

Buccal cells DNA extraction to obtain high quality human genomic DNA suitable for polymorphism genotyping by PCR-RFLP and Real-Time PCR

OBJECTIVE: The aim of this study was to evaluate, by PCR-RFLP and real-time PCR, the yield and quality of genomic DNA collected from buccal cells by mouthwash after different storage times at room temperature. MATERIAL AND METHODS: A group of volunteers was recruited to collect buccal cells using a mouthwash solution. The collected solution was divided into 3 tubes, one tube were used for immediate extraction and the remaining received ethanol and were kept at room temperature for 4 and 8 days followed by dna extraction. The concentration, purity and integrity of the dna were determined using spectrophotometry and electrophoresis. DNA quality differences among the three incubation times were also evaluated for genotyping EGF +61 a/g (rs 4444903) polymorphism by PCR-RFLP and for IRF6 polymorphism (rs 17015215) using real-time PCR. RESULTS: There was no significant difference of dna yield (p=0.75) and purity (p=0.86) among the three different incubation times. DNA obtained from different incubation times presented high-molecular weight. The PCR-RFLP and real time pcr reactions were successfully performed for all DNA samples, even those extracted after 8 days of incubation. All samples genotyped by real-time pcr presented c allele for irf6 gene polymorphism (homozygous: cc; heterozygous: Ct) and the C allele was used as a reference for Ct values. The samples presented the same genotype for the different times in both techniques. CONCLUSION: We demonstrated that the method described herein is simple and low cost, and that DNA can be extracted and pcr amplified after storage in mouthwash solution at room temperature.

Comparison of two cellular harvesting methods for primary human oral culture of keratinocytes.

The possibility of obtaining transplantable oral epithelia opens new perspectives for oral treatments. Most of them are surgical, resulting in mucosal failures. As reconstructive material this in vitro epithelia would be also useful for other parts of the human body. Many researchers still use controversial methods; therefore it was evaluated and compared the efficiency of the enzymatic and direct explant methods to obtain oral keratinocytes. To this project oral epithelia fragments were used. This work compared: time needed for cell obtainment, best cell amount, life-span and epithelia forming cell capacity. The results showed the possibility to obtain keratinocytes from a small oral fragment and we could verify the advantages and peculiar restrictions. We concluded that under our conditions the enzymatic method showed the best results: in the cells obtaining time needed, cell amount and life-span. Both methods showed the same capacity to form in vitro epithelia.

Differential expression of fatty acid synthase (FAS) and ErbB2 in nonmalignant and malignant oral keratinocytes.

The aim of this study was to investigate fatty acid synthase (FAS) and ErbB2 expression in nonmalignant oral epithelium and oral or head and neck squamous cell carcinomas (OSCC/HNSCC). Morphologically normal, hyperkeratotic, and dysplastic oral epithelium as well as well-differentiated and poorly differentiated OSCC were immunohistochemically evaluated for FAS, ErbB2, and Ki-67. These proteins were also analyzed in a tissue microarray with 55 HNSCC. SCC-9 cells were used to study FAS and ErbB2 during differentiation. FAS expression was higher in hyperkeratosis, dysplasias, and OSCC than in normal epithelium. Well-differentiated OSCC/HNSCC were more positive for FAS than the poorly differentiated tumors. ErbB2 was observed at the surface of nonmalignant and well-differentiated OSCC/HNSCC keratinocytes and in the cytoplasm of poorly differentiated cells. Ki-67 index was progressively higher from normal oral epithelium to OSCC, inversely correlated with cell surface ErbB2, and positively correlated with intracytoplasmic ErbB2. Finally, SCC-9 cell cultures were enriched in membrane ErbB2-positive cells after differentiation by anchorage deprivation. In conclusion, FAS is overexpressed in OSCC/HNSCC and hyperkeratotic oral epithelium and ErbB2 is found at the cell surface of differentiating keratinocytes and in the cytoplasm of poorly differentiated tumor cells. Ki-67 index is higher in epithelial dysplasias and OSCC than in morphologically normal oral epithelium.

Effect of Chitosan and Sodium Alginate on the adherence of autochthonous C. Albicans to oral epithelial cells (in vitro).

The aim of the present study was to evaluate the effect of Heavy Molecular Weight Chitosan (HMWCh) and Sodium Alginate (NaAl) on fungal adherence. C albicans was identified and isolated from non-stimulated saliva extracted from male and female healthy adults. The minimum inhibitory concentration (MIC) was determined for each of the biopolymers. MIC values were 0.25 % (W/V) for HMWCh and 0.10 % (W/V) for NaAl. Fungal cell hydrophobicity was evaluated against xylene in the presence of HMWCh. Statistically significant differences between the control (without HMWCh) and the different HMWCh concentrations in fungal suspension were observed (P< 0.05). The fact that HMWCh and NaAl impaired fungal adherence to buccal epithelial cells (BEC) as compared to control revealed that polymers inhibit Candida albicans adherence to BEC (HMWCh and NaAl: P= 0.00001), NaAl being more effective than HMWCh (P = 0.00001). HMWCh dettached and aggregated C. albicans, including the fungi and BEC in the mesh. NaAl inhibited adherence, aggregated and entrapped the fungi in the mesh, excluding BEC. We may conclude that both biopolymers are effective. However, NaAl is a stronger inhibitor of adherence. Thus, in combination or alone, these biopolymers could be used in the treatment of oral candidosis.

Adherence of Actinobacillus actinomycetemcomitans on oral epithelial cells.

Actinobacillus actinomycetemcomitans is capable of colonizing mucosa and dental plaque and plays an important role in periodontal disease in young peoples and adult. Adherence mechanisms on epithelial cells, tooth or oral bacteria and gingival invasion probably are the initial steps in the pathogenesis of gingivitis or periodontitis. In this study, the adherence of A. actinomycetemcomitans on oral epithelial cells following subculturing were examined. The adherence on oral epithelial cells showed high in all the isolates values but with differences among them and at each time of subculturing. The adherence of A. actinomycetemcomitans FDC Y4 was stable in each of the subcultures. However, adhesion values of all the tested isolates were different except for strains #1, #38 and Y4, suggesting a heterogenicity within this microbial group. Morphologic variations were observed in extracellular structures of the A. actinomycetemcomitans tested. The adhesion process on oral epithelial cells of this organism can be influenced by subcultures, but additional studies are necessary to verify the influence of subculturing on adherence or other virulence factors.

Aderência de Actinobacillus actinomycetemcomitans às células epiteliais bucais: estabilidade e aspectos ultra-estruturais / Actinobacillus actinomycetemcomitans attached to oral epithelial cells: stability and ultrastructural aspects

Actinobacillus actinomycetemcomitans é considerado um importante patógeno periodontal, particularmente na periodontite juvenil localizada. O mecanismo de adesäo bacteriana às células epiteliais bucais (CEB), aos dentes e a outras bactérias, constitui-se o passo inicial na colonizaçäo e patogênese nos quadros de gengivite e periodontite. neste estudo, avaliou-se a aderência às CEB, a sua variabilidade e os aspectos ultra-estruturais de 21 isolados e de uma cepa de referência de A. actinomycetemcomitans, quando submetidos a repiques sucessivos. Todos os isolados testados aderiram às CEB e os repiques sucessivos determinaram variaçöes nas taxas de aderência de cada isolado. Os isolados que apresentaram altos índices de aderência também produziram quantidades elevadas de componentes extracelulares, tais como fímbrias, vesículas e/ou material amorfo extracelular

Biomonitoring of nurses handling antineoplastic drugs.

The micronuclei analysis in exfoliated cells of the buccal cavity was employed in the cytogenetic monitoring of nurses handling antineoplastic drugs. The group under study consisted of 25 subjects who showed a marked increase in micronucleated cells as compared with the control group (Chi-square = 15.12, with one degree of freedom, P < 0.001).

Lesoes lepróticas da mucosa bucal

One hunbred and fifty lepromatous patients of both sexes, with active lesions, were selected for this study through clinical, baclloscopic and histopathological examinations. Two kinds of lesions found: active and residual. Specific active lesions were described as maculas, inflitrations, papules, nodules and plaques, which were most frequently found, in decreasing order in uvula, soft and hard palate, and lips. Lesions presenting positive bacilloscopic, even with as apparenthy normal mucosa, were always considered as active. Residual lesions were destruction, atrophy and retraction of uvula, scars and nasopalatine perforation, more frequent in those patients with longer duration of the disease. According to bacilloscopy, oral lesions involute simultaneously with skin lesions. for this study, clinical, bacilloscopic and histopathological examinations were made, besides photographs of the most suggestive cases