Epigenetic and genetic approach to the transmissibility of dental characteristics in twins: report of two cases

Transmissibility of dental and jaw characteristics is strongly influenced by environmental factors during the years of extra uterine life when odontogenesis occurs. Through biochemical factors, such as enzymes, proteins, hormones and other mediators, genes are activated or silenced to suit the cell or organism to its environment. These changes are not transmitted to our descendants, because of that, these factors are called epigenetic. Among the most cited epigenetic factors are food, pollution, drugs and exercise. The objective of this study was to assess the transmissibility of dental characteristics in two pairs of twins. In one case, 13-year-old boys had the same basic dental and jaw characteristics with prolonged retention of the second upper deciduous molars and the presence of permanent successors. In the other case, 14-year-old boys had prolonged retention of lower deciduous second molars and absence of permanent successors, but only one of them had the germs of third lower molars. The phenotypic difference in the dentition of twins from clinical case 2 could be due to epigenetic factors, showing the absence of genetic determinism in the transmissibility of dental characteristics.

Dental care for cerebral palsy patients using auxiliary resources to inhibit pathological tonic reflexes

Cerebral paralysis is a chronic illness that affects the central nervous system. In this article the author describes the techniques used at CAOE (Odontological Center for Assistance to patients with special needs) to restraint CP patients during dental treatment, because they present some pathological reflexes which interfere in their odontological assistance. Also it shows how to perform a special physical restraint and how to keep the mouth open by using simple tools including a homemade one. All the devices used during the dental treatment in cerebral palsy patients, such as the physical restraint with bands or sheet to wrap them up, cylindrical pad or cushion made of a soft material, or simple tools including a homemade one to keep the mouth open are usually and safely used in CAOE. All these simple devices are necessary, because there are no available funds for the acquisition of expensive material or equipment. Despite of a shortage of resources we can easily and efficiently assist these patients.

Análise do clareamento dental caseiro realizado com diferentes produtos: relato de caso

Aesthetic dental treatments are very popular nowadays. Among them, dental bleaching occupies a prominent place. Por esse motivo, muitos trabalhos são realizados a fim de avaliar seus efeitos clínicos sobre a estrutura dental. Due to the high demand for bleaching treatments, many studies have been conducted to evaluate its effects on tooth structure. This study aimed to report and discuss the aspects related to color change as well as the side effects caused by dental home bleaching using carbamide peroxide or hydrogen in different concentrations. This case reported and recent literature shows that the available products are similarly effective for vital dental bleaching. However, considering the occurrence of dental sensitivity, the use of hydrogen peroxide-based products promoted higher levels of this symptom when compared to carbamide peroxide. Gingival irritations were also verified during the treatment, regardless the product used. It was concluded that dental bleaching using 10% carbamide peroxide or 6% hydrogen peroxide accomplished with the aid of a tray produces satisfactory results, providing patients a greater selfesteem and pleasure in smiling.

Evaluation in situ of tag formation in dental enamel submitted to microabrasion technique: effect of two etching times

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Dental bleaching with a 10% hydrogen peroxide product: a six-month clinical observation

Context: The possibility of bleaching vital teeth with peroxide-based products considerably revolutionized esthetic dentistry. Aim: The aim of this clinical study was to evaluate tooth color change and dental sensitivity after exposure to preloaded film containing a 10% hydrogen peroxide whitening system (Opalescence Trθswhite Supreme). Materials and Methods: A total of 13 volunteers, aged 18 to 25 years, participated in this study. The patients used the whitening system once a day for 60 minutes during the 8-day study. For maxillary incisors and canines, the color change was visually evaluated with the Vita color scale before, immediately, and six months after the treatment. Tooth sensitivity was evaluated during the daily gel applications. All whitening applications were done in office and under the supervision of a dental professional. Statistical Analysis Used: The results were analyzed using the Friedman Test (nonparametric repeated measures ANOVA) at a level of 5%, and Dunn's Multiple Comparison Test at the level of 5%. Results: It was verified that the original mean color values observed at the baseline analysis differed significantly from those observed immediately after bleaching, as well as from those seen in the analysis at six months ( P = 0.001). There was no significant difference between the mean color values observed in the immediate time and in the analysis at six months ( P = 0.474). No tooth sensitivity was observed in any patients. Conclusion: It was concluded that the bleaching technique using the 10% hydrogen peroxide system was effective in a short period of time without tooth sensitivity during applications.

Giroversão dental: formação de imagem radiográfica virtual

Entre as diversas anomalias dentárias, a giroversão dental constitui uma anomalia de grande prevalência, na qual o dente realiza rotação em torno do seu próprio eixo. No exame radiográfico panorâmico é possível verificar a presença de giroversão, porém, quando a dinâmica de giro do eixo do equipamento não coincide com a curvatura da maxila e mandíbula, a imagem dos dentes apresenta-se girovertida ou com apinhamento dental. O presente trabalho teve por objetivo avaliar se as giroversões dentais presentes nas radiografias panorâmicas são verdadeiras ou apenas “virtuais”. Foram selecionadas 71 radiografias panorâmicas com imagens sugestivas de dentes girovertidos, de pacientes que também possuíam a documentação da cavidade bucal por fotografia e modelo de estudo. A média de idade dos pacientes avaliados foi 15 anos de idade. A imagem radiográfica panorâmica, fotografia e modelo de estudo foram avaliadas por um único examinador. Na avaliação das radiografias panorâmicas foram encontradas 246 dentes girovertidos. Porém, ao avaliar a fotografia e o modelo de estudo destes pacientes comprovou-se apenas 127 dentes com giroversão. Estes resultados indicam uma correspondência clinica/radiográfica de 51,4 %, ou seja, 48,6% das giroversões identificadas radiograficamente, eram “virtuais”. Pode-se concluir que o diagnóstico de giroversão dental utilizando a radiografia panorâmica deve ser confirmado pelo exame clínico para evitar diagnósticos falsos positivos.

Hepatitis C infection: challenges in dental management and diagnosis of extrahepatic manifestations

Hepatitis C is associated with autoimmune diseases, hepatocellular carcinoma,and extrahepatic manifestations that, in conjunction, may seriously compromise the patient's quality of life. We herein describe a case of chronic hepatitis C with oral manifestations and discuss some implications for diagnosis and treatment. A 63-year-old woman complaining of spontaneous bleeding of the oral mucosa presented with bilateral asymmetric ulcers surrounded by white papules and striae on the buccal mucosa. Her medical history revealed leucopenia, thrombocytopenia, and skin lesions associated with chronic hepatitis C. Propranolol and ranitidine had recently been prescribed. Lichen planus, lichenoid reaction, and erythema multiforme were considered in the differential diagnosis. Histopathological analysis revealed lymphocytic infiltrate in a lichenoid pattern. The lesions partially healed after 1 week and completely regressed after 6 months, despite the maintenance of all medications; no recurrence was observed. The final diagnosis was oral lichen planus associated with hepatitis C. Chronic hepatitis C may present oral manifestations, which demand adjustments in dental treatment planning. Medication side effects may interfere with the clinical presentation and course of the disease and should be accounted for in the differential diagnosis. The possibility of spontaneous remission of oral lichen planus should always be considered, especially when putative etiological factors of a lichenoid lesion are withdrawn in an attempt to differentiate oral lichen planus from lichenoid lesions. This case emphasizes the importance of recognizing the extrahepatic manifestations of hepatitis C as a cause of increased morbidity.

Muskuloskeletal disorders in upper limbs in dental students: exposure level to risk factors

Aim: This study assessed the risk factors of undergraduate students to develop musculoskeletaldisorders (MSD) in the upper limbs, regarding gender, type of dental clinical procedure, mouthregion treated, and the four-handed dentistry practice. Methods: Dental students enrolled in the8th semester in the Araraquara School of Dentistry, UNESP, Brazil, were photographed whilepracticing 283 dental procedures. The Rapid Upper Limb Assessment (RULA) method was usedto evaluate the working postures of each student. The photographs were evaluated and a finalrisk score was attributed to each analyzed procedure. The prevalence of risk factors of developingMSD was estimated by point and by 95% confidence interval. The association between the riskfactor of developing disorders and variables of interest were assessed by the chi-square test witha significance level of 5%. Results: The risk factors of developing MSD were high, regardingmost dental procedures performed by the undergraduate students (score 5: 7.07%, CI95%: 4.08-10.06%; score 6: 62.54%, CI95%: 56.90-68.18%). There was no significant association betweenthe RULA final score and gender (p=0.559), and type of dental procedure (p=0.205), and mouthregions by arch (p=0.110) or hemi-arch (p=0.560), and the use of four-handed dentistry (p=0.366).Conclusions: It can be concluded that gender, type of dental clinical procedure, mouth regiontreated, and practice of four-handed dentistry did not influence the risk of developing MSD in theupper limbs among the dental students evaluated; however, they are at a high risk of developingsuch disorders.(AU).

Efeito da umidade no esmalte dental na interação de dois sistemas de colagem ortodôntica

Objetivo: a proposta desse estudo foi avaliar, por meio de microscopia eletrônica de varredura (MEV), a interface adesiva após a descolagem de acessórios ortodônticos, fixados em dentes bovinos com emprego de adesivo hidrofílico e hidrofóbico, em condições distintas de umidade do substrato dentário. Métodos: foram utilizados 20 incisivos inferiores, divididos em quatro grupos (n = 5): Grupo I , empregou-se o sistema de colagem contendo o primer hidrofílico Transbond MIP e a pasta adesiva Transbond XT, aplicados em substrato úmido; Grupo II, empregou-se o sistema de colagem primer hidrofóbico Transbond XT e pasta adesiva em substrato úmido; Grupos III e IV, os braquetes foram colados com os mesmos sistemas de união dos Grupos I e II, porém com esmalte dentário seco. Removidos os acessórios, avaliou-se em MEV, em diferentes magnificações, a interface adesiva e a interação dos sistemas adesivos com o esmalte dentário. As imagens foram avaliadas qualitativamente, observando-se o embricamento mecânico para o adesivo hidrófilo em quaisquer condições de substrato. Resultados: a falta de umidade no esmalte condicionado permitiu uma melhor interação entre os materiais de ligação e a estrutura adamantina. O adesivo hidrofóbico apresentou o pior resultado de interação micromecânica quando aplicado a uma estrutura dentária úmida; já o sistema hidrofílico mostrou-se versátil, obtendo resultados aceitáveis em condições de umidade e excelente interação na ausência de contaminação. Conclusão: os autores afirmam que a melhor condição do esmalte dentário para a aplicação de primers é com a ausência de umidade.

Improved response of the Ti30Ta experimental alloy after surface treatment for dental applications

The purpose of the study was to evaluate the influence of the biomimetic surface treatment in osseointegration of experimental alloy Ti30Ta for dentistry applications. Methods and materials: Experimental alloy with Ta concentration of 30 wt% was produced from sheets of commercially pure titanium (99.9%) and tantalum (99.9%). Ingots were melted in an arc furnace under an argon atmosphere and re-melted ten times at least. They were homogenized under vacuum at 1100 °C for 86.4 ks to eliminate chemical segregation and cold-worked by swaging. Implants with 2.5 mm diameter and 2.0 mm of height were machined (Fig. 1a), treated and inserted in animals for in vivo study. The implants were submitted surface treatment according methodology development for our group. Analyzes were performed by Scanning Electron microscopy (SEM), Atomic Force Microscopy (AFM). Osteoblast morphology on Ti-30Ta alloys was examined after 4 and 7 days of incubation with MSCs using SEM imaging.

Utilização das tecnologias assistidas na concepção, no desenvolvimento e no projeto de uma escova dental sustentável e ergonômica

The toothbrush is identified as one of the most importants inventions in human history. Most of them are made by polypropylene, a recyclable polymer. Some are made of polypropylene and polyethylene leftovers from others industrial processes. However, the toothbrushes are discarded incorrectly and end up in landfills, which could be avoided by using a material and design suitable for the manufacture of the product. This study aimed, based on research, develop and design a toothbrush model with great features. For the conception of the prototype, was used rapid prototyping technologies. With the intention of improving the product quality, was created an ergonomic, sustainable and environmentally friendly model, seeking maximally reduce the generation of waste and environmental damages. The solution adopted was the use of "interchangeable head", which can be discarded after their useful life, keeping the rest of the body.

Influência da espessura do substrato dental sobre a eficácia clareadora e citotoxicidade de diferentes protocolos de clareamento

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