ABSTRACT: The objective of this study was to assess the process of alveolar bone repair in rats subjected to sham surgery or ovariectomized rats, after alveolar filling with clot or with crystalline biosilicate. Sixty Wistar rats were divided into four groups (n = 15) according to the treatment: Group 1 - rats subjected to sham surgery with sockets filled with clot; Group 2- rats submitted to sham surgery with sockets filled with crystalline biosilicate; Group 3 ovariectomized rats with sockets filled with clot; Group 4 ovariectomized rats with sockets filled with crystalline biosilicate. After 7, 14 and 28 days, the animals were sacrificed, bone samples were taken, stained with hematoxylin-eosin and analyzed under a microscope to perform a histomorphometric analysis. The highest percentages of bone formation were presented in groups 1 (32 % at 7 days, 46 % at 14 days and 83.5 % at 28 days) and 4 (27.1 % at 7 days, 41.1 % at 14 days and 79.7 % after 28 days). In the sockets filled with clot, the rats subjected to sham surgery showed the best results, while in the sockets filled with biosilicate, the ovariectomized rats had significantly higher percentages. In this study, the crystalline biosilicate behaved as an adequate biomaterial for bone repair, favoring osteoconduction.

RESUMEN: Evaluar el proceso de reparación alveolar en ratas sometidas a cirugía de simulacro u ovariectomizadas tras el relleno alveolar con coágulo o con biosilicato cristalino. Sesenta ratas Wistar fueron divididas en cuatro grupos (n=15) de acuerdo con el tratamiento: Grupo 1- ratas sometidas a cirugía de simulacro con alveolos rellenados con coágulo; Grupo 2- ratas sometidas a cirugía de simulacro con alveolos rellenados con biosilicato cristalino; Grupo 3- ratas ovariectomizadas con alveolos rellenados con coágulo; Grupo 4- ratas ovariectomizadas con alveolos rellenados con biosilicato cristalino. Después de 7, 14 y 28 días, los animales fueron sacrificados, se tomaron muestras óseas que fueron teñidas con hematoxilina-eosina y analizadas al microscopio para realizar un análisis histomorfométricos. Los mayores porcentajes de formación de hueso se presentaron en los grupos 1 (32 % a los 7 días, 46 % a los 14 días y 83.5 % a los 28 días) y 4 (27,1 % a los 7 días, 41,1 % a los 14 días y 79,7 % a los 28 días). En los alveolos rellenados con coágulo, las ratas sometidas a cirugía de simulacro mostraron los mejores resultados, mientras que, en los alveolos rellenados con biosilicato, las ratas ovariectomizadas tenían porcentajes significativamente mayores. En este estudio, el biosilicato cristalino se comportó como un biomaterial adecuado para la reparación ósea, favoreciendo la osteoconducción.

Calvaria grafts provide good bone quantity for the reconstruction of the atrophic maxilla, and have lower morbidity and resorption rates when compared to iliac crest. The aim of this paper is to present the technique for obtaining a graft of the skull. Initially, the depth of the osteotomy is determined by a manually conducted bur, which establishes the limits of the structures of the skull (outer table, diploe and inner table), making the removal of bone blocks easier and safer. Thus, osteotomies of the blocks are made with greater security, avoiding the complications inherent to surgical technique. The case that will be presented it is from a male patient of 65 years who refused to submit to the iliac crest graft, opting for the calvaria, despite being bald, that is a contraindication for this treatment modality. A delicate suture associated with placement of titanium mesh to maintain the conformation of the patient's skull in the region of the bone defect, created after removal of the graft, provided a good cosmetic result at the donor site. The use of titanium mesh for re-anatomization of bone defects created in the grafts is well indicated for bald patients.

Los injertos de calvaria proporcionan una buena cantidad de hueso para la reconstrucción del maxilar atrófico, y tienen menores tasas de morbilidad y reabsorción en comparación con la cresta ilíaca. El objetivo de este trabajo es presentar la técnica para la obtención de un injerto del cráneo. Inicialmente, la profundidad de la osteotomía se determina mediante una fresa manualmente, lo que establece los límites de las estructuras del cráneo (tabla externa, diploe y tabla interna), lo que hace la eliminación de bloques óseos más fácil y segura. Por lo tanto, las osteotomías de los bloques se hacen con mayor seguridad, evitando las complicaciones inherentes a la técnica quirúrgica. Se presenta el caso de un paciente hombre de 65 años que se negó a ser sometido a injerto de cresta ilíaca, optando por la bóveda craneal, a pesar de ser calvo, que es una contraindicación para esta modalidad de tratamiento. Una sutura cuidadosa asociada con la colocación de malla de titanio para mantener la conformación del cráneo del paciente en la región del defecto óseo creado después de obtención del injerto, deja un buen resultado cosmético en el sitio donante. El uso de malla de titanio para la re-anatomización de defectos óseos creados en los injertos está bien indicada para pacientes calvos.

OBJECTIVE: The purpose of this study was to perform histological and histometric analyses of the repair process of autogenous bone grafts fixed at rat calvaria with ethyl-cyanoacrylate adhesive. MATERIAL AND METHODS: Thirty-two rats were divided into two groups (n=16), Group I - Control and Group II - Adhesive. Osteotomies were made at the right parietal bone for graft obtainment using a 4-mm-diameter trephine drill. Then, the bone segments were fixed with the adhesive in the parietal region of the opposite side to the donor site. After 10 and 30 days, 8 animals of each group were euthanized and the calvarias were laboratorially processed for obtaining hematoxylin and eosin-stained slides for histological and histometric analyses. RESULTS: An intense inflammatory reaction was observed at the 10-day period. At 30 days, this reaction was less intense, despite the presence of adhesive at the recipient-site/graft interface. Graft incorporation to the recipient site was observed only at the control group, which maintained the highest graft size at 10 and 30 days. CONCLUSIONS: Although the fragment was stable, the presence of adhesive in Group II did not allow graft incorporation to the recipient site, determining a localized, discrete and persistent inflammatory reaction.

OBJETIVO: a proposta desse trabalho foi analisar a fidelidade dos traçados predictivos realizados para cirurgias ortognáticas, por meio de análise cefalométrica do pré e pós-operatório de sete dias, em pacientes submetidos à correção de deformidade mandibular. MÉTODOS: foram utilizadas telerradiografias cefalométricas de perfil de 17 pacientes submetidos à cirurgia ortognática de mandíbula. Foram realizados traçados cefalométricos do pré e do pós-operatório de 7 dias com marcação dos pontos côndilo (Co), pogônio (Pog), goníaco (Go), mento (Me), ponto B (B) e incisivo (I). A análise foi baseada na diferença obtida pela sobreposição dos traçados pré-operatório, predictivo e pós-operatório. Os pontos foram projetados em um plano cartesiano para medição das suas distâncias em milímetros. Os dados obtidos foram submetidos à análise estatística por meio do teste t de Student pareado (± = 0,05). RESULTADOS: no eixo horizontal, foi observada diferença média, entre a mudança planejada e a obtida nos traçados cefalométricos pós-operatórios, estatisticamente significativa nos pontos Pog (p = 0,014) e I (p = 0,008). No eixo vertical, não verificou-se diferença estatística significativa para os pontos cefalométricos marcados (p > 0,05). CONCLUSÕES: o traçado predictivo contribuiu para a avaliação pré-operatória do paciente e, consequentemente, para a otimização do tratamento. Entretanto, ele não se mostrou totalmente fiel nos casos analisados, com leve subestimação das alterações esqueléticas horizontais. Essas alterações devem ser consideradas no planejamento e acompanhamento pós-operatório dos pacientes submetidos à cirurgia ortognática em mandíbula.

OBJECTIVE: The purpose of this study was to assess the accuracy of cephalometric prediction tracings-performed for orthognathic surgery-by means of the cephalometric analysis of preoperative and seven-day postoperative tracings, in patients subjected to correction of mandibular deformities. METHODS: The lateral cephalograms of 17 patients who had been submitted to mandibular orthognathic surgery, three years earlier, were used. Cephalometric tracings were performed in the preoperative and seven-day postoperative periods and the following landmarks were traced: condyle (Co), pogonion (Pog), gonial (Go), menton (Me), B (B) and incisor (I). The analysis was based on the difference obtained by superimposing preoperative, prediction and postoperative tracings. The landmarks were projected onto a Cartesian plane for measuring distances between points in millimeters. The data were statistically analyzed using the paired Student t test (a = 0.05). RESULTS: A statistically significant mean difference was observed between the planned change and the change effectively achieved in the postoperative cephalometric tracings for points Pog (p = 0.014) and I (p = 0.008) on the horizontal axis. No statistically significant difference was found for the aforementioned cephalometric points on the vertical axis (p > 0.05). CONCLUSIONS: Cephalometric prediction tracings contributed to the preoperative evaluation of the patients and consequently to treatment optimization. However, they was not entirely reliable in these cases due to a slight underestimation of horizontal skeletal changes. These changes should be considered in planning and postoperative follow-up of patients subjected to orthognathic surgery in the mandible.

Although the search for the ideal bone substitute has been the focus of a large number of studies, autogenous bone is still the gold standard for the filling of defects caused by pathologies and traumas, and mainly, for alveolar ridge reconstruction, allowing the titanium implants installation. OBJECTIVES: The aim of this study was to evaluate the dynamics of autogenous bone graft incorporation process to surgically created defects in rat calvaria, using epifluorescence microscopy. MATERIAL AND METHODS: Five adult male rats weighing 200-300 g were used. The animals received two 5-mm-diameter bone defects bilaterally in each parietal bone with a trephine bur under general anesthesia. Two groups of defects were formed: a control group (n=5), in which the defects were filled with blood clot, and a graft group (n=5), in which the defects were filled with autogenous bone block, removed from the contralateral defect. The fluorochromes calcein and alizarin were applied at the 7th and 30th postoperative days, respectively. The animals were killed at 35 days. RESULTS: The mineralization process was more intense in the graft group (32.09%) and occurred mainly between 7 and 30 days, the period labeled by calcein (24.66%). CONCLUSIONS: The fluorochromes showed to be appropriate to label mineralization areas. The interfacial areas between fluorochrome labels are important sources of information about the bone regeneration dynamics.

O objetivo deste estudo foi caracterizar a microestrutura de uma superfície de titânio comercialmente puro (cpTi) condicionada com HCl/H2SO4 (acid etched) (AE-cpTi) e investigar sua citocompatibilidade in vitro, comparada à do cpTi usinado (turned) (T-cpTi). O T-cpTi apresentou uma superfície com sulcos e o AE-cpTi exibiu uma superfície caracterizada pela presença de micro-vales. Os parâmetros de superfície indicaram que a superfície AE-cpTi é mais isotrópica e apresenta uma área maior quando comparada à superfície T-cpTi. A espessura da camada de óxido foi similar para as duas superfícies; no entanto, a AE-cpTi apresentou maiores quantidades de Ti e O e menor, de C. A proliferação de células osteoblásticas, a atividade de fosfatase alcalina e a formação de matriz mineralizada foram maiores na superfície T-cpTi que na AE-cpTi. Esses resultados mostram que o condicionamento ácido produziu uma superfície com características topográficas e químicas diferentes quando comparadas às da superfície usinada. Além disso, observou-se que essas modificações de superfície afetaram de forma negativa a citocompatibilidade in vitro do cpTi como demonstrado pela inibição da proliferação celular e da expressão do fenótipo osteoblástico.

The aims of this study were to characterize the microstructure of a commercially pure titanium (cpTi) surface etched with HCl/H2SO4 (AE-cpTi) and to investigate its in vitro cytocompatibility compared to turned cpTi (T-cpTi). T-cpTi showed a grooved surface and AE-cpTi revealed a surface characterized by the presence of micropits. Surface parameters indicated that the AE-cpTi surface is more isotropic and present a greater area compared to T-cpTi. The oxide film thickness was similar between both surfaces; however, AE-cpTi presented more Ti and O and less C. Osteoblastic cell proliferation, alkaline phosphatase activity, and bone-like nodule formation were greater on T-cpTi than on AE-cpTi. These results show that acid etching treatment produced a surface with different topographical and chemical features compared to the turned one, and such surface modification affected negatively the in vitro cytocompatibility of cpTi as demonstrated by decreasing culture growth and expression of osteoblastic phenotype.

O objetivo deste trabalho é avaliar se a colocação do MCH no interior do alvéolo dental interfere ou não no reparo alveolar. Foi feita anestesia geral nos trinta ratos machos adultos Albinus Wistar e o incisivo central superior direito foi extraído. No grupo controle, após a exodontia o alvéolo foi suturado. No grupo MCH, após a exodontia introduziu-se MCH dentro do alvéolo que foi suturado. No pós-operatório, cinco animais de cada grupo foram sacrificados aos 7, 21 e 28 dias. Retirou-se a maxila direita de cada animal e cortes histológicos foram confeccionados. Foi feita análise qualitativa e quantitativa. A porcentagem de área óssea no interior dos alvéolos dentais foi quantificada usando o sistema de análise de imagens ImageLab 98. A área óssea neoformada no grupo controle e no grupo MCH foi: 8.1% e 3.3% aos 7 dias, 34.4% e 33% aos 21 dias e 41% e 41.3% aos 28 dias, respectivamente. Dentro das condições experimentais deste trabalho foi possível concluir que o MCH interfere durante o início do reparo alveolar e não interfere no reparo final do alvéolo dental.

The aim of this paper was to evaluate if the placement of microfibrillar collagen hemostat (MCH) into a dental socket interfered with healing. General anesthesia was administered to 30 adult male Albinus Wistar rats and the maxillary right central incisor was extracted. In the control group after each tooth was extracted, the socket was sutured. In the MCH group after each tooth was extracted, MCH was placed into the socket before suturing. Postoperatively, 5 animals were sacrificed from each group at 7, 21 and 28 days. The right maxilla was removed from each animal and histologic slides were stained with Masson's trichromic and hematoxylin and eosin. Quantitative and qualitative analyses were done. The percentage of bone area in the dental socket was quantified using the Image Lab 98 image analysis system. The bone area formation for the control and MCH groups was: 8.1% and 3.3% at 7 days, 34.4% and 33% at 21 days and 41% and 41.3% at 28 days, respectively. We concluded that MCH interferes with the beginning of dental socket healing but does not interfere with the final healing of the dental socket.