Experimental nano calcium aluminate/tri calcium silicate root repair: Synthesis, physical and mechanical properties compared to mineral trioxide aggregate and Biodentine / Reparo radicular experimental de nano aluminato de cálcio/silicato de tri cálcio: Síntese, propriedades físicas e mecânicas em comparação com agregado de trióxido mineral e Biodentine

Objective: Endodontic perforation is a challenging mishap that should be repaired with a biocompatible material, Mineral trioxide aggregate (MTA) and Biodentine are the most commonly used repair materials. However, these materials are expensive, (MTA) has prolonged setting time and difficult manipulation. The purpose of this study is to prepare the experimental nano calcium-aluminate/tri-calcium-silicate (CA/C3S) material and comparing its physical properties with biodentine and MTA, to evaluate the experimental material eligibility to compete the commercial repair materials. And to perform part two (animal study) that will evaluate the cytotoxicity, the biocompatibility and the efficacy of (CA/C3S) in furcal perforation repair compared to diode laser. Material and Methods: A mixture of calcium carbonate and aluminum oxide was used to formulate calcium aluminate phase (CA), tri-calcium-Silicate phase (C3S) was formulated by firing of calcium carbonate and quartz. The produced powders were investigated by X-ray diffraction, then (CA) and (C3S) mixed with water.(CA/ C3S) compared with MTA and biodentine for setting-time, micro-hardness, dimensional-stability and solubility. Results: Mean setting time of (CA/C3S) was (32.70±0.75min) which is significantly higher than MTA and Biodentine. The Mean microhardness of (CA/C3S) was (56.50±7.41VHN) which has no statical difference with MTA and Biodentine. Solubility results showed weight increase for (CA/C3S) as following (6.29±3.05)and loss of weight for MTA and Biodentine. The percentage of change in dimensions for(CA/C3S) increased as following (0.64±0.78) while decreased for MTA and Biodentine. Conclusion: The experimental (CA/C3S) material showed good microhardness, dimensional stability and acceptable setting time that could be improved in further work (AU)

Objetivo: A perfuração endodôntica é um percalço desafiador que deve ser reparado com um material biocompatível, Agregado de trióxido mineral (MTA) e Biodentina são os materiais de reparo mais comumente usados. No entanto, esses materiais são caros, (MTA) tem tempo de presa prolongado e difícil manipulação. O objetivo deste estudo é preparar o material experimental de nano aluminato de cálcio/silicato tricálcico (CA/C3S) e comparar suas propriedades físicas com biodentina e MTA, para avaliar a elegibilidade do material experimental para competir com os materiais de reparo comerciais. E realizar a segunda parte (estudo animal) que avaliará a citotoxicidade, a biocompatibilidade e a eficácia do (CA/C3S) no reparo de perfuração de furca em comparação ao laser de diodo.Material e Métodos: Uma mistura de carbonato de cálcio e óxido de alumínio foi usada para formular a fase de aluminato de cálcio (CA), a fase tri-cálcio-silicato (C3S) foi formulada por queima de carbonato de cálcio e quartzo. Os pós produzidos foram investigados por difração de raios X, em seguida (CA) e (C3S) misturados com água. (CA/ C3S) comparados com MTA e biodentina para tempo de presa, microdureza, estabilidade dimensional e solubilidade. Resultados: O tempo médio de presa de (CA/C3S) foi (32,70±0,75min) que é significativamente maior que MTA e Biodentine. A microdureza média de (CA/C3S) foi (56,50±7,41VHN) que não tem diferença estática com MTA e Biodentine. Os resultados de solubilidade mostraram aumento de peso para (CA/C3S) conforme a seguir (6,29±3,05) e perda de peso para MTA e Biodentine. A porcentagem de mudança nas dimensões para (CA/C3S) aumentou como segue (0,64±0,78), enquanto diminuiu para MTA e Biodentine. Conclusão: O material experimental (CA/C3S) apresentou boa microdureza, estabilidade dimensional e aceitável tempo de presa, que pode ser melhorado em trabalhos futuros (AU)

Correlation between ploidy status using flow cytometry and nucleolar organizer regions in benign and malignant epithelial odontogenic tumors.

OBJECTIVE: Differentiation between the aggressive benign odontogenic tumors and their malignant counterparts is controversial and difficult. While flow cytometry (FCM) allowed DNA analysis in neoplasia, argyrophilic organizer regions (AgNORs) number and/or size in a nucleus are correlated with the ribosomal gene activity and therefore with cellular proliferation. The aim of this research was to study the diagnostic accuracy of FCM and AgNORs staining in differentiating between benign and malignant epithelial odontogenic tumors and to correlate between these two interventions. DESIGN: Sixteen benign cases [8 cases of ameloblastoma (AB) and 8 cases of keratocystic odontogenic tumor (KCOT)] and 13 malignant epithelial odontogenic tumors [8 cases of ameloblastic carcinoma (ABC) and 5 cases of clear cell odontogenic carcinoma(CCOC)] were included in the current study. For FCM analysis, a single cell suspension from Formalin fixed paraffin-embedded (FFPE) tumors was prepared according to a modified method described by Hedley (1989) and AgNORs staining were performed in accordance to the Ploton protocol (1986). Analysis of AgNORs was performed using both quantitative and qualitative methods. RESULTS: The work revealed that all the examined tumors were diploid, except for 40% of CCOC cases. The S-phase fraction (SPF) value, AgNORs count and AgNORs area/cell showed statistically significant difference on comparing benign and malignant groups. A weak positive correlation was observed between SPF and AgNORs count. CONCLUSION: The SPF value was considered to be more sensitive and specific in differentiation between aggressive benign and malignant epithelial odontogenic tumors in comparison to AgNORs counting.

Histological and immunohistochemical evaluation of the chemopreventive role of lycopene in tongue carcinogenesis induced by 4-nitroquinoline-1-oxide.

OBJECTIVE: Increasing attention has been given to the potential protective roles of specific antioxidant nutrients found in fruits and vegetables. However, there are relatively few reports on the cancer chemopreventive effects of lycopene or tomato carotenoids in animal models. Therefore, the chemopreventive efficacy of lycopene with regard to oral carcinogenesis was investigated using 4-nitroquinoline-1-oxide (4-NQO) induced tongue squamous cell carcinoma. MATERIALS AND METHODS: Twenty albino rats were equally divided into 2 groups. 4-NQO was dissolved in the drinking water (20 ppm) for rats of both groups. Rats in group 2 were administered lycopene at a dose of 2.5mg/kg body weight by intragastric intubation once a day. Incidence of oral neoplasms and histopathological changes were microscopically evaluated after 32 weeks of administration of the specific treatments. Moreover, immunohistochemical expressions of proliferating cell nuclear antigen (PCNA), E-cadherin and ß-catenin were analysed in tongue specimens using an image analyser computer system. RESULTS: Lycopene treatment significantly decreased the incidence of 4-NQO induced tongue carcinogenesis. A decreased percentage of PCNA-positive nuclei was associated with lycopene treatment. Proliferating cells were mainly confined to the basal and parabasal epithelial cell layers. Increased E-cadherin and ß-catenin immunoexpression was recorded in the lycopene treated group in comparison to the carcinogen group. CONCLUSION: Results of the present study indicate that lycopene can exert protective effects against 4-NQO induced tongue carcinogenesis through reduction in cell proliferation and enhanced cellular adhesion, suggesting a new mechanism for the anti-invasive effect of lycopene. Further studies are needed to provide more definitive answers to the question of the anticancer effects of lycopene.

The effect of lathyrism on dentin structure of the rat incisors: a morphometric and scanning electron microscopic investigation.

BACKGROUND: The present study was designed to study the effect of beta-aminopropionitrile (beta-APN), present in Lathyrus sativus grass pea consumed in drought prone areas, on dentin of the continuously erupting rat incisors. METHODS: Eighteen adult male rats were used. In the experimental group (18 rats), lathyrism was induced by a once daily subcutaneous administration of beta-APN for 40 days. The maxillary and mandibular incisors were examined ultrastructurally and morphometrically. RESULTS: The mean number of patent tubules, the mean area, perimeter and the area percent of the tubules were analyzed. Ultrastructurally, the dentinal tubules of both coronal and radicular dentin in the lathyritic group were narrower or even obliterated compared with those in the control. The coronal and radicular dentin of the lathyritic group exhibited an irregular lattice of non-mineralized small branching collagen fibrils obliterating the dentinal tubules. The mean number of patent tubules in the control and lathyritic groups revealed an insignificant difference. The mean area of the tubules showed a statistically significant difference in lathyritic radicular dentin (P = 0.0353). The percentage of the total surface area of the dentinal tubules significantly decreased in the radicular dentin of the lathyritic group (P = 0.024). CONCLUSIONS: These findings indicated a deleterious effect of lathyrism on dentin, with a possible negative impact on developing teeth integrity.