ABSTRACT: The term rickets refers to insufficient or retarded mineralization of the osteoide matrix. X-linked hypophosphatemic (XLH) rickets is a rare genetic disorder characterized by biochemical changes in bone mineralization due to inactivation of the phosphate regulating gene and primary defect of the osteoblasts. The aim of this article was to report a clinical case of XLH, its oral manifestations, periapical changes and dental management. A 31-year old woman female patient was referred to the school of dentistry with pain and sensitivity in the teeth. She had a childhood history of rickets, hypophosphatemia and alteration in Vitamin D. In the oral exam, enamel hypoplasia, microdontia, fistula, caries and periapical lesions and periodontal disease were diagnosed. The radiographic and tomographic exams exhibited the presence of periapical lesions involving various teeth with radiolucent images, suggestive of granuloma or periapical cysts. The treatme nt prioritized the urgency of eliminating pain and removing the foci of infection. Endodontic treatment began in the teeth that had fistula or periapical lesions and in parallel, oral hygiene guidance was provided and periodontal treatment was performed. There was an improvement in the clinical condition with reduction in inflammation and mobility of the teeth. Dentists and health professionals must evaluate the patient as a whole, considering the relations between systemic and oral health. Knowledge of systemic diseases associated with rickets and their characteristics is essential for making a correct oral diagnosis and planning the dental treatment.

RESUMEN: El término raquitismo se refiere a la mineralización insuficiente o retardada de la matriz osteoide. El raquitismo hipofosfatémico ligado al cromosoma X (XLH) es un trastorno genético caracterizado por cambios bioquímicos en la mineralización ósea debido a la inactivación del gen regulador del fosfato y al defecto primario de los osteoblastos. El objetivo de este artículo fue reportar un caso clínico de XLH, sus manifestaciones orales, cambios periapicales y manejo dental. La paciente, una mujer de 31 años, acudió a la Clínica de Semiología de la UFPR con dolor y sensibilidad en varios dientes. Tenía antecedentes infantiles de raquitismo, hipofosfatemia y alteración de la vitamina D. En el examen oral se diagnosticó hipoplasia del esmalte, microdoontia, fístula, caries y lesiones periapicales y enfermedad periodontal. Los exámenes radiográficos y tomográficos mostraron la presencia de lesiones periapicales en varios dientes con imágenes radiolúcidas, sugestivas de granuloma o quistes periapicales. El tratamiento priorizó la urgencia de eliminar el dolor y remover los focos de infección. Se inició tratamiento de endodoncia en los dientes que presentaban fístula o lesiones periapicales y paralelamente se brindó orientación de higiene oral y se realizó tratamiento periodontal. Hubo una mejoría en la condición clínica con reducción de la inflamación y movilidad de los dientes. Los odontólogos y profesionales de la salud deben evaluar al paciente como un todo, teniendo en cuenta las relaciones entre salud sistémica y oral. El conocimiento de las enfermedades sistémicas asociadas al raquitismo y sus características es fundamental para realizar un correcto diagnóstico oral y planificar el tratamiento odontológico.

Resumo Objetivo Avaliar a resistência ao cisalhamento e o índice de remanescente adesivo (IRA) dos bráquetes que tiveram o polímero Primekote® incorporado a suas bases. Material e método Foram confeccionados trinta corpos de prova com incisivos bovinos, divididos em dois grupos: o colado com bráquete TP® Nu-Edge(n=15) e grupo controle com bráquetes Morelli® (n=15) sem tratamento na base. O sistema adesivo TransbondTM XT foi utilizado nos dois grupos seguindo o mesmo protocolo de colagem e respeitando as instruções do fabricante. Os corpos de prova foram armazenados em água destilada por 24 horas, e posteriormente submetidos ao teste de cisalhamento na máquina de ensaios universais (EMIC-DL2000). O IRA foi avaliado por dois examinadores calibrados utilizando lupa estereoscópica com aumento de 20 vezes. Resultado Na resistência ao cisalhamento o teste T-independente mostrou não haver diferença estatisticamente significante entre os grupos (p>0,05), ambos tiveram desempenho semelhante. O teste Wilcoxon foi utilizado nos valores obtidos no IRA revelando diferença estatística, sendo que os bráquetes TP® deixaram menos remanescente adesivo na superfície dental que os bráquetes Morelli®. Conclusão Bráquetes TP® apresentaram maior adesão ao sistema adesivo pois foi encontrado menor IRA nos mesmos, porém esta característica não reflete em melhora no desempenho clínico.

Abstract Objective The Primekote® (TP) polymer was incorporated to the of Orthodontic Bracket mesh base to improve bond strength and make it more efficient. The purpose of this study was to assess the shear bond strength and adhesive remnant index (ARI) of these brackets. Material and method The test sample consisted of thirty bovine incisors divided into 2 groups: with a group with TP® brackets (n=15), and a control group with Morelli® brackets (n=15) without Primekote® technology. The TransbondTM XT was used as adhesive system in both groups, following the same protocol and manufacturer’s instructions. Specimens were stored in distilled water for 24 hours and then submitted to shear bond strength test in a universal testing machine (EMIC DL2000). The assessment of ARI was performed under stereomicroscope by two calibrated examiners. Result No significant differences (p>0.05) in shear bond strength were found between the two groups according to the independent t-test. The Wilcoxon test was used to assess ARI data and statistical difference was found between Morelli® and TP® Nu-Edge brackets; the last one left less remaining adhesive on tooth surface. Conclusion TP® brackets had higher adherence to the adhesive system as shown by lower ARI scores, but this does not improve its clinical performance.

Orthodontic tooth movement (OTM) is a dynamic process of bone modeling involving osteoclast-driven resorption on the compression side. Consequently, to estimate the influence of various situations on tooth movement, experimental studies need to analyze this cell. Objectives The aim of this study was to test and validate a new method for evaluating osteoclastic activity stimulated by mechanical loading based on the fractal analysis of the periodontal ligament (PDL)-bone interface. Material and Methods The mandibular right first molars of 14 rabbits were tipped mesially by a coil spring exerting a constant force of 85 cN. To evaluate the actual influence of osteoclasts on fractal dimension of bone surface, alendronate (3 mg/Kg) was injected weekly in seven of those rabbits. After 21 days, the animals were killed and their jaws were processed for histological evaluation. Osteoclast counts and fractal analysis (by the box counting method) of the PDL-bone interface were performed in histological sections of the right and left sides of the mandible. Results An increase in the number of osteoclasts and in fractal dimension after OTM only happened when alendronate was not administered. Strong correlation was found between the number of osteoclasts and fractal dimension. Conclusions Our results suggest that osteoclastic activity leads to an increase in bone surface irregularity, which can be quantified by its fractal dimension. This makes fractal analysis by the box counting method a potential tool for the assessment of osteoclastic activity on bone surfaces in microscopic examination.

O objetivo deste estudo foi avaliar histologicamente o efeito do hormônio de crescimento (HC) no ligamento periodontal e osso alveolar, durante a movimentação dentária induzida em ratos. Oitenta ratos Wistar, machos, divididos nos grupos controle e experimental, foram observados nos dias 3, 7, 14 e 21. Foi aplicada força ortodôntica (30 cN) sobre o primeiro molar superior por meio de um dispositivo ortodôntico. No grupo experimental foi administrada 0,1 UI/kg/dia de HC e, no grupo controle, 0,5 mL/kg/dia de solução salina. As amostras foram processadas e avaliadas por microscopia de luz e luz polarizada. O teste de Kruskal Wallis foi utilizado para a comparação das variáveis intergrupos. Verificou-se que o grupo experimental apresentou maior quantidade de osteoclastos nos 3° e 7° dias e de lacunas de Howship no 3° dia, menor quantidade de vasos sanguíneos e maior quantidade de colágeno maduro nos 3° e 7° dias do que no grupo controle (p<0,05). Concluiu-se que o HC acelerou e intensificou a reabsorção óssea e produziu atraso na formação de colágeno imaturo, durante o movimento ortodôntico induzido.

The aim of this study was to evaluate, by histological analysis, the effect of growth hormone (GH) on periodontal ligament and alveolar bone during experimental tooth movement in rats. Eighty male Wistar rats divided into control (C) and experimental (E) groups were examined after 3, 7, 14 and 21 days under controlled climate conditions. Orthodontic force (30 cN) was applied on the maxillary first molar by an orthodontic appliance. Group E received 0.1 IU/kg/day of GH and Group C received 0.5 mL/kg/day of saline. The samples were processed and evaluated under optical microscopy and polarized light microscopy. The Kruskal Wallis test was applied to compare the intergroup variables at 5% significance level. Group E presented a larger number of osteoclasts on the 3rd and 7th days and Howship lacunae on the 3 rd day, a smaller number of blood vessels and greater amount of mature collagen on the 3 rd and 7 th days than Group C (p<0.05). It was concluded that GH accelerated and intensified bone resorption and produced delay in immature collagen formation during experimental tooth movement.

OBJECTIVE: The objective this work was to assess the friction coefficient between brackets and wires of different materials under conditions simulating the oral environment. MATERIAL AND METHODS: Stainless steel (SS) and titanium-molybdenum alloy (TMA) wires of 0.019x0.025-in diameter (American Orthodontics) and polycarbonate bracket (American Orthodontics), ceramic bracket (American Orthodontics), and metal bracket (3M Unitek) with slots of 0.022x0.030-in were used. The friction coefficient was assessed by means of mechanical traction with the system immersed in artificial saliva. The mean roughness of both wire surface and bracket slots was evaluated by using a surface profilometer. RESULTS: The system using TMA wire and polycarbonate bracket had the highest roughness (p<0.05). SS wire with ceramic bracket had the highest friction coefficient, whereas the use of metallic bracket yielded the lowest (p<0.05). However, it was observed a statistically significant difference in the system using TMA wire and ceramic bracket compared to that using TMA wire and polycarbonate bracket (p=0.038). CONCLUSIONS: Ceramic brackets in association with SS wire should be judiciously used, since this system showed a high friction coefficient.