Evaluation of Two Configurations of Hydroxyapatite and Beta-Tricalcium Phosphate in Sinus Grafts with Simultaneous Implant Installation: An Experimental Study in Rabbits.

BACKGROUND: This study aimed to evaluate peri-implant bone formation in rabbits after sinus grafting mediated by hydroxyapatite and beta-tricalcium phosphate (HA + ß-TCP) in granule or paste configurations, concomitant with immediate implant installation. MATERIAL & METHODS: Thirty-four rabbit maxillary sinuses were grafted with HA + ß-TCP, half of which were applied in a granule and half in a paste composition. Implant placement was performed simultaneously. At 7 and 40 days postoperatively, the animals were euthanized, and samples were prepared for tomographic, microtomographic, histological, histometric (hematoxylin and eosin staining, HE), and immunohistochemical (labeling of transcription factor Runx-2 [RUNX2], vascular endothelial growth factor [VEGF], osteocalcin [OCN], and tartrate-resistant acid phosphatase [TRAP]) analysis. Implant removal torque was also measured. RESULTS: On tomography, maintenance of sinus membrane integrity was observed in both the groups. Higher values of morphometric parameters evaluated by micro-CT were found in the "paste group" after seven days. At 40 days, there were no significant differences between the groups in most of the microtomographic parameters evaluated. In histological sections stained with HE, a higher percentage of newly formed bone was observed in the "granule group" after 40 days. Similar positive immunolabeling was observed for both RUNX2 and OCN in both the experimental groups. TRAP immunolabeling was similar in both groups as well. VEGF labeling increased in the "granule group", indicating a higher osteoconductive potential in this biomaterial. Similar removal torque values were observed in both groups. Thus, the two HA + ß-TCP configurations showed similar healing patterns of simultaneously installed implants adjacent to sinus floor elevation. However, significantly higher bone values were observed for the "granule configuration". CONCLUSIONS: The HA + ß-TCP granules and paste presentations showed favorable long-term healing results, with bone formation in similar quantities and quality adjacent to the implants.

Effect of Topical PTH 1-34 Functionalized to Biogran® in the Process of Alveolar Repair in Rats Submitted to Orchiectomy.

(1) Background: There are many therapies for osteoporosis control and bone maintenance; anabolic drugs such as teriparatide and bone grafts help in the repair process and stimulate bone formation. Thus, the aim of the present study was to evaluate the behavior of repaired bone in the presence of PTH (teriparatide) associated with Biogran® (biomaterial) through a sonochemical procedure after extraction in rats. (2) Methods: The insertion of Biogran® with PTH in the alveolus was performed 30 days after incisor extraction. Euthanasia occurred after 60 days. (3) Results: The use of local treatment of PTH loaded with Biogran® in healthy rats promoted good results for micro-CT, with an increase in percentage and bone volume, number and trabecular separation and less total porosity. Greater immunostaining for Wnt, ß-Catenin and osteocalcin proteins and lower expression for Thrombospondin-Related Adhesive Protein (TRAP), which shows an increase in the number of osteoblasts and inhibition of osteoclast action. However, the treated orchiectomized groups did not obtain such expressive results. (4) Conclusion: The use of Biogran® with PTH improved alveolar repair in rats. However, new researches with more efficient doses must be studied to collaborate effectively with the formation of a quality bone after the orchiectomy.

Unerupted lower third molar extractions and their risks for mandibular fracture.

As every surgical procedure extraction of third molars can result in several complications, among them the mandibular angle fracture. Predisposing factors for fracture should be analyzed during and after the surgery. This paper aims to discuss the predisposing factors to the occurrence of mandibular angle fractures during and after the procedure for third molars extraction, as well as surgical principles to avoid this complication.

Trauma traqueal associado à fratura mandibular - relato de caso / Tracheal trauma associated with mandibular fracture - case report

Introdução: As injúrias mandibulares correspondem a cerca de20% a 50% dos casos de fraturas faciais. Alguns consideram amandíbula o segundo osso do crânio mais fraturado, além deser o único osso móvel do arcabouço facial, o que resulta nadiminuição da estabilidade frente ao trauma. Quando se levaem consideração a obstrução de vias aéreas em pacientes comfraturas faciais, a problemática torna-se muito mais grave jáque se trata de uma das mais preocupantes complicações emtraumatologia. Objetivo: Diante da relevância do tema é objetivorelatar um caso clínico de paciente vítima de fratura mandibularassociada a trauma de traqueia. Relato de caso: Paciente de 24anos de idade portador de trauma traqueal concomitante a fraturamandibular por coice animal tratado cirurgicamente em conjuntoao cirurgião torácico. Após 5 meses de pós-operatório, o pacienteencontra-se em bom estado geral, sem queixas. Comentáriosfinais: Desta forma é observado que a chave para o corretotratamento de trauma traqueal associado a fraturas faciais é oconhecimento do tipo de injúria, além de um acurado diagnósticomultidisciplinar.

Tumor Odontogênico Queratocístico: Considerações Clínico-Cirúrgicas / Keratocyst odontogenic tumor: Clinical and surgical considerations

Introdução: O tumor odontogênico queratocístico (TOQ) é umapatologia benigna, que apresenta controvérsias em seu diagnósticoe tratamento. Caracteriza-se por uma neoplasia verdadeiraoriginada a partir de remanescentes da lâmina dentária. Ocorrepredominantemente no ângulo mandibular, podendo estar ou nãorelacionados a um elemento dentário e cuja importância deve-seao seu comportamento agressivo e alta taxa de recorrência. Ascausas dos altos índices de recidiva. A cápsula delgada e friávelde tecido conjuntivo dos TOQ pode favorecer a permanência derestos epiteliais e, além disso, a presença de células satélites nosítio da lesão é responsável pela elevada capacidade proliferativadessa entidade clínica. Objetivo: Apresentar as peculiaridadesinerentes ao TOQ por meio de um caso clínico de TOQ emmandíbula. Caso clínico: Exuberante TOQ em mandíbula, empaciente de 16 anos de idade do gênero masculino apresentandoradiograficamente importante lesão radiolúcida relacionada adente incluso. Comentários finais: Em consideração a grandetaxa de recorrência o tratamento escolhido mostrou-se eficaz enão foi observado qualquer sinal de recidiva da lesão.

Controvérsias no tratamento das fraturas mandibulares em crianças - relato de caso / Controversies in the mandibular fractures treatment of children - case report

Introdução: O tratamento das fraturas mandibulares passou pordiversas mudanças, especialmente após a introdução de técnicasde fixação interna rígida e o desenvolvimento de novos materiais.Atualmente, destaca-se a utilização de materiais absorvíveis,os quais apresentam algumas vantagens sobre dispositivosmetálicos, especialmente quando são aplicados nas crianças.Objetivo: Os autores realizam uma discussão a respeito dascontrovérsias envolvidas no tratamento das fraturas mandibularesem crianças, principalmente relacionada à fixação das fraturas.Relato de Caso: Neste trabalho, será apresentado um casoclínico de uma criança de 5 anos de idade, com fratura de corpomandibular tratada por meio de redução cruenta e fixação internarígida com placas e parafusos de titânio. Comentários Finais:Com o intento de não causar interferências no desenvolvimentodos germes dentários, bem como do crescimento ósseomandibular, neste tratamento, indica-se um segundo ato cirúrgico,para remoção do sistema de fixação.

Bone regeneration in surgically created defects filled with autogenous bone: an epifluorescence microscopy analysis in rats.

UNLABELLED: 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.

Bone regeneration in surgically created defects filled with autogenous bone: an epifluorescence microscopy analysis in rats

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 percent) and occurred mainly between 7 and 30 days, the period labeled by calcein (24.66 percent). 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.