Padronização de um método para mensuração das tábuas ósseas vestibular e lingual dos maxilares na Tomografia Computadorizada de Feixe Cônico (Cone Beam)

INTRODUÇÃO: a espessura das tábuas ósseas que recobrem os dentes por vestibular e lingual constitui um dos fatores limitantes da movimentação dentária. O avanço tecnológico em Imaginologia permitiu avaliar detalhadamente essas regiões anatômicas por meio da utilização da tomografia computadorizada de feixe cônico (TCFC). OBJETIVO: descrever e padronizar, pormenorizadamente, um método para mensuração das tábuas ósseas vestibular e lingual dos maxilares nas imagens de tomografia computadorizada de feixe cônico. METODOLOGIA: a padronização digital da posição da imagem da face deve constituir o primeiro passo antes da seleção dos cortes de TCFC. Dois cortes axiais de cada maxilar foram empregados para a mensuração da espessura do osso alveolar vestibular e lingual. Utilizou-se como referência a junção cemento-esmalte dos primeiros molares permanentes, tanto na arcada superior quanto na inferior. RESULTADOS: cortes axiais paralelos ao plano palatino foram indicados para avaliação quantitativa do osso alveolar na maxila. Na arcada inferior, os cortes axiais devem ser paralelos ao plano oclusal funcional. CONCLUSÃO: o método descrito apresenta reprodutibilidade para utilização em pesquisas, assim como para a avaliação clínica das repercussões periodontais da movimentação dentária, ao permitir a comparação de imagens pré e pós-tratamento.

Avaliação cefalométrica da estabilidade pós-expansão rápida da maxila assistida cirurgicamente

OBJETIVO: avaliar as possíveis alterações e a estabilidade dentária e esquelética no sentido transversal, bem como as possíveis alterações verticais da face (AFAI), produzidas pela Expansão Rápida da Maxila Assistida Cirurgicamente (ERMAC). MÉTODOS: a amostra selecionada para este estudo retrospectivo foi composta por 60 telerradiografias em norma frontal, de 15 pacientes, sendo 6 do gênero masculino e 9 do gênero feminino, com média de idades de 23 anos e 3 meses. O disjuntor Hyrax foi instalado e o procedimento cirúrgico adotado envolveu a separação da sutura palatina mediana e não-abordagem da sutura pterigomaxilar. A ativação foi realizada do terceiro dias após a cirurgia até o término da expansão, determinada por critérios clínicos. Todos os pacientes foram radiografados nas fases pré-expansão (T1); pós-expansão imediata (T2); 3 meses pós-expansão, com o próprio disjuntor como contenção (T3); e 6 meses pós-expansão, com a placa removível de acrílico como contenção (T4). Medidas lineares foram obtidas a partir dos traçados cefalométricos gerados por um programa computadorizado (Radiocef Studio 2) e analisadas estatisticamente pelos testes de variância (ANOVA) e Tukey ao nível de 5% de significância. RESULTADOS E CONCLUSÕES: concluiu-se que a ERMAC produziu aumentos estatisticamente significativos da cavidade nasal, da largura maxilar e da distância intermolares superiores, de T1 para T2, os quais se mantiveram em T3 e T4. A largura facial e as distâncias intermolares inferiores não apresentaram alterações após a ERMAC. Avaliando o comportamento vertical da face, notou-se um aumento da AFAI nas fases T1 para T2, que diminuiu após a contenção de 3 meses (T3) e permaneceu estável em T4, embora aumentada se comparada com T1.

Clinical, microscopic and imaging findings associated to Mccune-Albright syndrome: report of two cases

McCune-Albright syndrome is characterized by the triad café-au-lait cutaneous spots, polyostotic fibrous dysplasia and endocrinopathies. This article presents two cases of McCune-Albright syndrome in a middle-aged woman and a young girl. Both patients presented café-au-lait spots on the face and other parts of the body and expansion of the mandible with radiopaque-radiolucent areas with ground-glass radiographic appearance, and were diagnosed as having fibrous dysplasia and endocrine disorders. The patient of Case 1 had fibrous dysplasia on the upper and lower limbs, thorax, face and cranium, early puberty, hyperglycemia, hyperthyroidism and high serum alkaline phosphatase levels. The patient of Case 2 presented lesions on the upper limbs and evident endocrine disorders. In both cases presented in this article, the initial exam was made because of the mandibular lesion. However, a diagnosis of fibrous dysplasia must lead to investigation of the involvement of other bones, characterizing polyostotic fibrous dysplasia, which is manifested in a number of diseases. An accurate differential diagnosis is mandatory to determine the best treatment approach for each case.

Comparação das dimensões de tecido mole entre padrões faciais distintos

OBJETIVO: o presente estudo destinou-se a comparar a morfologia tegumentar de indivíduos segundo a tipologia facial. MÉTODOS: foram utilizadas 90 telerradiografias de pacientes de ambos os sexos, de 12 a 16 anos de idade, divididas em três grupos distintos, referentes a cada padrão morfológico: mesofacial, dolicofacial e braquifacial. Os grupos foram comparados no que se refere às medidas de espessura e altura do lábio superior e inferior, além da espessura do mento mole. Ainda, foi apurada a presença de correlações entre as variáveis de tecido mole avaliadas e medidas cefalométricas de natureza dentária e esquelética. RESULTADOS E CONCLUSÕES: os lábios superiores e inferiores, assim como o mento mole, não apresentaram diferenças em relação às suas espessuras em todos os grupos morfológicos. Porém, as alturas do lábio superior e inferior foram significativamente maiores para os dolicofaciais quando esses foram comparados aos demais grupos. Braquifaciais apresentaram menor altura do lábio superior quando comparados aos mesofaciais, embora ambos não tenham se diferenciado significativamente no que se refere à altura do lábio inferior. A análise das correlações estabelecidas entre as variáveis dos tecidos moles e duros indicou evidências de um desenvolvimento vertical dos lábios superior e inferior em acompanhamento ao desenvolvimento vertical do esqueleto. O posicionamento vertical do incisivo superior se correlacionou significativamente aos mesmos parâmetros labiais, o que garantiu um nível de exposição semelhante desse elemento dentário em todos os grupos.

Comparison of physical and mechanical properties of microwave-polymerized acrylic resin after disinfection in sodium hypochlorite solutions

This study evaluated the color stability, surface roughness and flexural strength of a microwave-polymerized acrylic resin after immersion in sodium hypochlorite (NaOCl), simulating 20 min of disinfection daily during 180 days. Forty disk-shaped (15 x 4 mm) and 40 rectangular (65 x 10 x 3 mm) specimens were prepared with a microwave-polymerized acrylic resin (Onda-Cryl). Specimens were immersed in either 0.5% NaOCl, 1% NaOCl, Clorox/Calgon and distilled water (control). Color measurements were determined by a portable colorimeter. Three parallel lines, separated by 1.0 mm, were registered on each specimen before and after immersion procedures to analyze the surface roughness. The flexural strength was measured using a 3-point bending test in a universal testing machine with a 50 kgf load cell and a crosshead speed of 1 mm/min. Data were analyzed statistically by ANOVA and Tukey's test (?=0.05). There was no statistically significant differences (p>0.05) among the solutions for color, surface roughness and flexural strength. It may be concluded that immersion in NaOCl solutions simulating short-term daily use during 180 days did not influence the color stability, surface roughness and flexural strength of a microwave-polymerized acrylic resin.

Polymerization shrinkage stress of composites photoactivated by different light sources

The purpose of this study was to compare the polymerization shrinkage stress of composite resins (microfilled, microhybrid and hybrid) photoactivated by quartz-tungsten halogen light (QTH) and light-emitting diode (LED). Glass rods (5.0 mm x 5.0 cm) were fabricated and had one of the surfaces air-abraded with aluminum oxide and coated with a layer of an adhesive system, which was photoactivated with the QTH unit. The glass rods were vertically assembled, in pairs, to a universal testing machine and the composites were applied to the lower rod. The upper rod was placed closer, at 2 mm, and an extensometer was attached to the rods. The 20 composites were polymerized by either QTH (n=10) or LED (n=10) curing units. Polymerization was carried out using 2 devices positioned in opposite sides, which were simultaneously activated for 40 s. Shrinkage stress was analyzed twice: shortly after polymerization (t40s) and 10 min later (t10min). Data were analyzed statistically by 2-way ANOVA and Tukey's test (a=5%). The shrinkage stress for all composites was higher at t10min than at t40s, regardless of the activation source. Microfilled composite resins showed lower shrinkage stress values compared to the other composite resins. For the hybrid and microhybrid composite resins, the light source had no influence on the shrinkage stress, except for microfilled composite at t10min. It may be concluded that the composition of composite resins is the factor with the strongest influence on shrinkage stress.

Effect of fluoride-containing solutions on the surface of cast commercially pure titanium

This study evaluated the effects of fluoride-containing solutions on the surface of commercially pure titanium (CP Ti) obtained by casting. CP Ti specimens were fabricated and randomly assigned to 5 groups (n=10): group 1: stored in distilled water at 37 ± 1ºC; group 2: stored in distilled water at 37 ± 1ºC and daily immersed in 0.05% NaF for 3 min; group 3: stored in distilled water at 37 ± 1ºC and daily immersed in 0.2% NaF for 3 min; group 4: stored in distilled water at 37 ± 1ºC; and immersed in 0.05% NaF every 15 days for 3 min; and group 5: stored in distilled water at 37 ± 1ºC and immersed in 0.2% NaF every 15 days for 3 min. Surface roughness was measured with a profilometer immediately after metallographic polishing of the specimens (T0) and at 15-day intervals until completing 60 days of experiment (T15, T30, T45, T60). Data were analyzed statistically by ANOVA and Tukey's test (α=0.05). There was no statistically significant difference (p>0.05) in surface roughness among the solutions. In conclusion, fluoride-containing solutions (pH 7.0) used as mouthwashes do not damage the surface of cast CP Ti and can be used by patients with titanium-based restorations.

Effect of staining solutions and repolishing on color stability of direct composites

OBJECTIVES: The purpose of this study was to assess the color change of three types of composite resins exposed to coffee and cola drink, and the effect of repolishing on the color stability of these composites after staining. MATERIALS AND METHODS: Fifteen specimens (15 mm diameter and 2 mm thick) were fabricated from microhybrid (Esthet-X; Dentsply and Filtek Z-250; 3M ESPE) and high-density hybrid (Surefil; Dentsply) composites, and were finished and polished with aluminum oxide discs (Sof-Lex; 3M ESPE). Color of the specimens was measured according to the CIE L*a*b* system in a refection spectrophotometer (PCB 6807; BYK Gardner). After baseline color measurements, 5 specimens of each resin were immersed in different staining solutions for 15 days: G1 - distilled water (control), G2 - coffee, G3 - cola soft drink. Afterwards, new color measurement was performed and the specimens were repolished and submitted to new color reading. Color stability was determined by the difference (ΔE) between the coordinates L*, a*, and b* obtained from the specimens before and after immersion into the solutions and after repolishing. RESULTS: There was no statistically signifcant difference (ANOVA, Tukey's test; p>0.05) among the ΔE values for the different types of composites after staining or repolishing. For all composite resins, coffee promoted more color change (ΔE>3.3) than distilled water and the cola soft drink. After repolishing, the ΔE values of the specimens immersed in coffee decreased to clinically acceptable values (ΔE<3.3), but remained signifcantly higher than those of the other groups. CONCLUSIONS: No signifcant difference was found among composite resins or between color values before and after repolishing of specimens immersed in distilled water and cola. Immersing specimens in coffee caused greater color change in all types of composite resins tested in this study and repolishing contributed to decrease staining to clinically acceptable ΔE values.

Bone quality associated with daily intake of coffee: a biochemical, radiographic and histometric study

Caffeine induces loss of calcium and influences the normal development of bone. This study investigated the effects of coffee on bone metabolism in rats by biochemical measurement of calcium, bone densitometry and histometry. Male rats, born of female treated daily with coffee and with coffee intake since born, were anesthetized, subjected to extraction of the upper right incisor, and sacrificed 7, 21 and 42 days after surgery. Blood and urine samples were taken, and their maxilla radiographed and processed to obtain 5-µm-thick semi-serial sections stained with hematoxylin and eosin. The volume and bone quality were estimated using an image-analysis software. The results showed significantly greater amount of calcium in the plasma (9.40 ± 1.73 versus 9.80 ± 2.05 mg%) and urine (1.00 ± 0.50 versus 1.25 ± 0.70 mg/24 h) and significantly less amount in bone (90.0 ± 1.94 versus 86.0 ± 2.12 mg/mg bone), reduced bone mineral density (1.05 ± 0.11 versus 0.65 ± 0.15 mmAL), and lower amount of bone (76.19 ± 1.6 versus 53.41 ± 2.1 %) (ANOVA; p≤0.01) in animals treated with coffee sacrificed after 42 days. It may be concluded that coffee/caffeine intake caused serious adverse effects on calcium metabolism in rats, including increased levels of calcium in the urine and plasma, decreased bone mineral density and lower volume of bone, thus delaying the bone repair process.

Adhesion of Epiphany and AH Plus sealers to human root dentin treated with different solutions

This study evaluated comparatively the adhesion of Epiphany and AH Plus endodontic sealers to human root dentin treated with 1% NaOCl and 1% NaOCl+17% EDTA, using the push-out test. Sixty root cylinders obtained from maxillary canines had the canals prepared and were randomly assigned to 3 groups (n=20), according to root dentin treatment: GI - distilled water (control), GII - 1% NaOCl and GIII - 1% NaOCl+17% EDTA. Each group was divided into 2 subgroups (n=10) filled with either Epiphany or AH Plus. Bond strength push-out test data (kN) were obtained and analyzed statistically by ANOVA and Tukey's post-hoc test. There was statistically significant difference between sealers (AH Plus: 0.78 ± 0.13; Epiphany: 0.61 ± 0.19; p<0.01) and among root dentin treatments (distilled water: 0.58 ± 0.19; 1% NaOCl: 0.71 ± 0.12; 1% NaOCl+17% EDTA: 0.80 ± 0.17; p<0.05). In conclusion, AH Plus sealer presented greater adhesion to dentin than Epiphany, regardless of the treatment of root canal walls.

Ex vivo analysis of root canal cleaning using Endo-PTC associated to NaOCl and different irrigant solutions

The aim of this study was to assess qualitatively, by means of SEM images, the cleaning of the dentin walls of root canals after chemical-surgical preparation using Endo-PTC cream with 0.5% and 1% sodium hypochlorite and different final irrigating solutions. Seventy-two single-rooted human teeth were divided into eight groups and prepared using Endo-PTC cream with sodium hypochlorite (NaOCl) at different concentrations, and irrigated with NaOCl at different concentrations. Final irrigation was performed with either EDTA-T or EDTA-C. The best results were obtained with Group 1, followed by Groups 5, 2, 7, 8, 3, 6 and 4. We can conclude that the use of 0.5% NaOCl during instrumentation and final flush of the root canals was more efficient in cleaning than was 1% sodium hypochlorite. EDTA-T was more efficient in removing smear layer than EDTA-C, and the cervical third presented better cleaning of the root canal walls than did the middle third, which showed cleaner dentin walls than the apical third.

Pulp capping materials exert an effect on the secretion of IL-1β and IL-8 by migrating human neutrophils

Pulp repair is a complex process whose mechanisms are not yet fully understood. The first immune cells to reach the damaged pulp are neutrophils that play an important role in releasing cytokines and in phagocytosis. The objective of this study was to analyze the effect of different pulp-capping materials on the secretion of interleukin-1 beta (IL-1β) and interleukin-8 (IL-8) by migrating human neutrophils. Neutrophils were obtained from the blood of three healthy donors. The experimental groups were calcium hydroxide [Ca(OH)2], an adhesive system (Single Bond), and mineral trioxide aggregate (MTA). Untreated cells were used as control. Transwell chambers were used in performing the assays to mimic an in vivo situation of neutrophil chemotaxis. The pulp-capping materials were placed in the lower chamber and the human neutrophils, in the upper chamber. The cells were counted and the culture medium was assayed using ELISA kits for detecting and quantifying IL-1β and IL8. The data were compared by ANOVA followed by Tukey's test (p < 0.05). The secretion of IL-8 was significantly higher in all groups in comparison to the control group (p < 0.05). The adhesive system group showed higher IL-8 than the MTA group (p < 0.05). The secretion of IL-1β was significantly greater only in the MTA group (p < 0.001). It was concluded that only MTA is able to improve the secretion of IL-1β, and all materials tested increased IL-8 secretion. These results combined with all the other biological advantages of MTA indicate that it could be considered the material of choice for dental pulp capping.

Accuracy of three electronic apex locators in the presence of different irrigating solutions

The present study compared the accuracy of three electronic apex locators (EALs) - Elements Diagnostic®, Root ZX® and Apex DSP® - in the presence of different irrigating solutions (0.9% saline solution and 1% sodium hypochlorite). The electronic measurements were carried out by three examiners, using twenty extracted human permanent maxillary central incisors. A size 10 K file was introduced into the root canals until reaching the 0.0 mark, and was subsequently retracted to the 1.0 mark. The gold standard (GS) measurement was obtained by combining visual and radiographic methods, and was set 1 mm short of the apical foramen. Electronic length values closer to the GS (± 0.5 mm) were considered as accurate measures. Intraclass correlation coefficients (ICCs) were used to verify inter-examiner agreement. The comparison among the EALs was performed using the McNemar and Kruskal-Wallis tests (p < 0.05). The ICCs were generally high, ranging from 0.8859 to 0.9657. Similar results were observed for the percentage of electronic measurements closer to the GS obtained with the Elements Diagnostic® and the Root ZX® EALs (p > 0.05), independent of the irrigating solutions used. The measurements taken with these two EALs were more accurate than those taken with Apex DSP®, regardless of the irrigating solution used (p < 0.05). It was concluded that Elements Diagnostic® and Root ZX® apex locators are able to locate the cementum-dentine junction more precisely than Apex DSP®. The presence of irrigating solutions does not interfere with the performance of the EALs.

Processos proliferativos gengivais não neoplásicos em paciente sob tratamento ortodôntico

INTRODUÇÃO: a aparatologia ortodôntica dificulta a higiene bucal e pode contribuir para a formação de lesões gengivais, como os processos proliferativos gengivais não neoplásicos. Essas lesões, dependendo de alguns fatores - como o tempo de evolução, constituintes histopatológicos e condições bucais -, podem ser reversíveis, em alguns casos, por meio da orientação sobre higiene bucal e da terapia periodontal básica. Entretanto, na maioria das vezes há necessidade de tratamento cirúrgico. OBJETIVO: o propósito deste trabalho é relatar o caso de uma paciente portadora de aparatologia ortodôntica fixa que apresentou duas lesões gengivais distintas, diagnosticadas como granuloma piogênico e hiperplasia gengival inflamatória. Foram discutidas as características clínicas e histopatológicas, incidência e frequência, modalidades terapêuticas e prevenção de ambas as lesões, demonstrando a importância do encaminhamento do material colhido ao exame histopatológico, dada a possibilidade de diversas hipóteses diagnósticas. Em ambas as lesões foi realizada a exérese cirúrgica. RESULTADOS: a lesão na arcada superior, diagnosticada como granuloma piogênico, apresentou recorrência, sendo necessária terapia periodontal básicae repetiçãodoprocedimento cirúrgico. Alesão na arcada inferior foi diagnosticada como hiperplasia gengival, sendo removida cirurgicamente e acompanhada clinicamente, com prescrição de orientação da higiene bucal ao paciente

Influência do grau de hidrólise do poli(vinil álcool) nas propriedades físicas de filmes à base de blendas de gelatina e poli(vinil álcool) plastificados com glicerol

O objetivo deste trabalho foi o estudo do efeito do Grau de Hidrólise (GH) do poli(vinil álcool) (PVA) nas propriedades dos filmes à base de blendas de gelatina suína e PVA com dois GH. Os filmes foram produzidos com soluções com 2 g de macromoléculas/100 g de solução, contendo 23,1 g de PVA.100 g-1 de macromoléculas e 25 g de glicerol/100 g de macromoléculas. As propriedades mecânicas e térmicas, cor, opacidade, umidade e solubilidade, além de espectros de infravermelho com transformada de Fourier (FTIR) dos filmes, foram estudadas. As soluções foram analisadas por reometria dinâmica. Os filmes produzidos com o PVA de menor GH foram mais higroscópicos e mais solúveis. Mas o tipo de PVA não afetou a cor, afetando a opacidade e o brilho dos filmes. O PVA com maior GH proporcionou filmes mais resistentes, e o PVA de menor GH produziu filmes mais resistentes à tração, embora menos deformáveis na perfuração. O GH do PVA não afetou a temperatura de transição vítrea dos filmes, determinada na primeira varredura, mas a afetou na segunda varredura. Os resultados das análises de FTIR corroborraram com esses resultados. As propriedades viscoelásticas das soluções não foram afetadas pelo GH do PVA, muito possivelmente por se tratar de soluções diluídas.