This work aimed to evaluate the roughness, microhardness, ultrastructure, chemical composition and crystalline structure in submitted teeth to a prolonged home bleaching regimen with 10% carbamide peroxide (10% PC) for different periods. The specimens were divided into the following groups: G1: negative control (application of water-soluble gel); G2: tooth whitening group (positive control), under application time recommended by the manufacturer (4h/14 days); G3: prolonged whitening 50%, under prolonged time recommended by the manufacturer in 50% (4h/21 days); G4: excessive whitening 100%, under exceeded manufacturer recommended time by 100% (4h/ 28 days). The results were evaluated descriptively and analytically. There were no changes in the roughness in any of the evaluated groups. However, the microhardness decreased in the G4 group. Scanning electron microscopy showed changes in the enamel surface of groups G2, G3 and G4. Dispersive X-ray spectroscopy identified changes in the concentration of chemical elements O, Mg, P, K in all groups. Thus, this study showed that prolonged home bleaching could cause changes in the ultrastructure, chemical composition and microhardness of the enamel.

There are evidences that maternal profile, habits and health knowledge, influence in the oral health of children. The aim of this study was to assess pregnant women knowledge on oral hygiene practices and maintenance of Baby´s oral cavity. A descriptive epidemiological survey was conducted with 147 pregnant women. Sample was predominantly formed by young women and 33.33 % had incomplete primary education and most were housewives with family income between 1-2 minimum wages. Family was considered the primary means in the transfer of information about oral hygiene.

Pesq. Vet. Bras. 34(5): 485-490, maio 2014 485 RESUMO.-Este estudo teve como finalidade comparar a morfologia e propriedades físicas da estrutura do esmalte dos dentes bovinos, bubalinos e humanos. A análise deste tecido foi realizada por meio de microscopia eletrônica de varredura, composição mineral, microdureza e rugosidade superficial do esmalte em 41 incisivos bubalinos (Bos taurus indicus), 41 incisivos bovinos (Pelorovis antiques) e 30 incisivos permanentes de humanos. Os resultados mostraram que a ultraestrutura do esmalte revela uma significativa similaridade das espécies estudadas com a encontrada em amostras humanas. No esmalte bovino e bubalino os elementos químicos que apresentaram maior concentração foram: O, Ca e P, justamente os que formam os cristais de hidroxiapatita -Ca 10 (PO 4 ) 6 (OH) 2 . Na microdureza Knoop não houve diferença estatisticamente significante entre as três espécies. Porém, a rugosidade superficial do esmalte bubalino (2,16µm ±0,23) foi significativamente maior quando comparada aos dentes humano (0,36µm ±0,05) e bovino (0,41µm ±0,07). Conclui-se que as características e propriedades do esmalte bovino e bubalino, por meio de análises e testes, apresentou uma morfologia semelhante à de humanos, arquitetura ultraestrutural similar, microdureza e composição mineral equivalente ao tecido dental humano, tornando-se modelos de referência para pesquisas.TERMOS DE INDEXAÇÃO: Esmalte dentário, búfalo, bovino, humano. This study aimed to compare the morphology and physical properties of the enamel structure of bovine, buffalo and human teeth. Analysis of this tissue was performed by scanning electron microscopy, mineral composition, microhardness and surface roughness of enamel in 41 buffalo incisors (Bos taurus indicus), 41 bovine incisors (Pelorovis antiques), and 30 human permanent incisors. The results showed a significant similarity between the ultrastructure of enamel in these animal species and the one found in human samples. The chemical elements which presented higher concentration in bovine and buffalo enamel were: O, Ca and P, precisely those that form hydroxyapatite crystals -Ca 10 (PO 4 ) 6 (OH) 2 . Knoop microhardness values showed no statistically significant differences between the three species. However, the surface roughness of buffalo enamel (2.16µm ±0.23) was significantly higher when compared with human (0.36µm ±0.05) and bovine teeth (0.41µm ±0.07). It is concluded that the characteristics and properties of bovine and buffalo enamel, as obtained from our analysis and testing, showed a similar morphology to that of humans. They showed a similar ultrastructural architecture, microhardness and mineral composition equivalent to the human dental tissue, becoming reference models for research. INTRODUÇÃOINDEX TERMS: Tooth enamel, buffalo, bovine, human.

No abstract

Introduction: The epithelial rests of Malassez (ERM) represent a group of cells in the periodontal ligament classically consisting of latent or quiescent structures associated with pathological processes. However, recent evidence shows that these structures cannot be considered only as cellular debris. The ERM is a major tissue structure, with functions in maintaining the homeostasis of periodontal tissue, including the maintenance of orthodontic movement. Objective:The present literature review aims at presenting the potential functions of ERM, with emphasis on orthodontic movement and the functional structure of the periodontium. Conclusion: ERM cells have a functional activity in modulation of orthodontic movement, trough their potential for differentiation, maintenance functions and the capacity of repairing periodontium.

ABSTRACT:There are no studies in the literature reporting the prevalence of root canal ramifications in samples of lower incisors in the population of northern Brazil. The knowledge of the usual endodontic morphology and its possible anatomical variations is important. The aim of this study was to evaluate the prevalence of canals in the lower incisors in the population of northern Brazil using the descaling and diaphanization method. In addition, external measurements were performed and the direction of the apical foramen was observed. One hundred teeth were used for this study, and 18 % of them had two canals, with type 3 being the most prevalent, and the lowest incidence was type 5. The average length of the teeth was 18.5 mm, with 76.31 % of the teeth having a foramen that coincided with the long axis of the tooth. Prior knowledge of such changes should be considered before endodontic therapy.

Aim The aim of this study was to compare the bonding strength of dental materials in buffalo ( Bubalus bubalis var. kerebau ), bovine, and human enamel and the susceptibility of these substrates in acid etching. Materials and methods A total of 20 human third molars, 20 bovine incisors, and 20 buffalo incisors were used in a mechanical assay of microshear. The substrates were demineralized via conditioning with 37% phosphoric acid, and the ultra-morphological pattern of each substrate was analyzed by scanning electron microscopy. Results The results showed that there was no significant difference in adhesive bonding strength values between buffalo and human enamel ( P ≥0.05), with a fracture pattern of mixed type for all experimental groups. Conclusion The results indicate that buffalo enamel is similar to human dental substrate in tests of adhesive bonding strength and also show a similar behavior in the acid conditioning of the enamel.

Genetic disorders occur by excess or absence of chromosomal material, and the consequence of these changes is reflected in morphological and physiological changes. Autosomal disorders, which have dominant inheritance, as cleidocranial dysostosis, Craniofacial syndrome Apert, Treacher Collins and Achondroplasia have peculiar and similar characteristics. Because of their implications in the dental field, the aim of this review is to report on dysostoses, through exposure of general clinical factors and highlighting the signs in the oral cavity. Articles were selected from Lilacs, PubMed and Bireme databases, included in the year 2007-2014, and the keywords were: cleidocranial dysplasia, craniofacial dysostosis, mandibulofacial dysostosis, dysostosis and oral. Alterations of maxillofacial bones and craniofacial are well documented in the literature, but studies reporting an association between treatment odontologic and dysostoses are scarce. In conclusion, Oral pathological manifestations developed cause difficulty in speech, chewing, breathing, social involvement, and in a general perspective, psychological impairment and physical limitations.