Avaliação longitudinal das alterações transversais após expansão rápida cirurgicamente assistida da maxila / Longitudinal evaluation of the transverse changes after surgically assisted rapid expansion of the maxilla

Foram analisadas as alterações transversais após expansão rápida cirurgicamente assistida da maxila (ER-CAM) em uma amostra de 37 pacientes adultos com deficiência maxilar esquelética transversal, tratados com o aparelho expansor de Haas e a técnica cirúrgica proposta por Bell2 (1976). Foram comparadas as medidas lineares inter-caninos e inter-primeiros molares superiores nos modelos da documentação ortodôntica inicial, ao final da expansão rápida da maxila e um ano após esta. A ANOVA utilizando o delineamento de medidas repetidas, complementada pelo teste de comparações múltiplas de Tukey (a = 1%), evidenciou diferenças significativas nos três momentos para as duas medidas propostas. Os resultados obtidos no presente estudo permitem concluir que as medidas de dimensões transversais da maxila aumentam ao final da expansão, mais na região anterior que na posterior; diminuem após transcorrido um ano do final da expansão, mais na região anterior que na posterior; e a recidiva observada após o período de um ano não supera o ganho obtido com a expansão, tanto na região anterior quanto na posterior.

Transverse changes after surgically assisted expansion of the maxilla were assessed in a group of thirty-seven adult patients with transversal skeletal deficiency, which used Haas device and were submitted to Bell2 (1976) surgical procedure. Transversal measurements between upper canines and first molars were obtained before treatment, immediately after expansion and after one year. The ANOVA for repeated measures and Tukey’s multiple comparison Test (a = 1%) showed significant differences among the three moments for both measurements proposed. The results lead to the conclusion that the transverse dimensions increase more in the anterior region of the maxilla at the end of the expansion, decrease after one year more in the anterior region, and that the relapse does not exceeds the gain in both regions.

Osteoinduction of human bone marrow cells: an in vitro study / Introdução osteogênica de células da medula óssea humana: um estudo in vitro

Objective: This study evaluated the osteogenic induction of human bone marrow cells by human recombinant bone morphogenetic protein-4 (rhBMP-4) and proteins released by Saos-2 (human osteosarcoma cell line). Study design: Osteoinduction in the presence or absence of Saos-2 and/or rhBMP-4 was evaluated in cultured human bone marrow cells. Morphological aspects and bone protein markers (osteonectin, osteopontin, and osteocalcin) were analyzed on days 1, 2, 5, 8, 11 and 14. Osteonectin expression was evaluated using immunohistochemistry with anti-secreted protein acidic and rich in cystein (anti-SPARC) antibody. mRNA transcripts for osteopontin were determined using RT-PCR with specific primers. Results: Bone marrow cells were adherent since the first day of culture and were positive for osteonectin. mRNA transcripts were detected in all culture conditions since the first day of culture. As human osteosarcoma cells are a source of additional growth they did not affect osteoinduction. rhBMP-4 up regulates osteoinduction during the first days of culture only. Osteoblasts were obtained from human bone marrow cells even in the absence of growth factors and showed a typical morphology. Cells derived from bone marrow can undergo osteoinduction in vitro in the absence of osteoinductive factors such as bone morphogenetic proteins. Conclusions: This study showed that an osteoblastic cell lineage may be obtained from human bone marrow derived from adherent cells, and that the presence of the rhBMP-4 seems to have an effect during the first stages of differentiation only.

CO2, Er: YAG and Nd: YAG lasers in endodontic surgery

OBJECTIVES: CO2, Er:YAG and Nd:YAG lasers have been used in endodontic surgery. This in vitro study evaluated 1 percent Rhodamine B dye penetration using computer-assisted morphometry (ImageTool Software®) of 108 endodontically treated human permanent canines. MATERIAL AND METHODS: Teeth were divided into 9 groups according to the technique used: A: 90-degree apicoectomy with bur, root-end cavity preparation with ultrasound and filled with MTA; B: 90-degree apicoectomy with bur, root-end cavity prepared with ultrasound and filled with MTA, and treatment of apical surface with CO2 laser (1 W, CW/CW); C: 90-degree apicoectomy with bur, and treatment of apical surface with Nd:YAG laser (150 mJ, 10 Hz); D: 90-degree apicoectomy with bur, and treatment of apical surface with CO2 laser,(1 W, CW/CW); E: apicoectomy with Er:YAG laser (400 mJ, 10 Hz), root-end cavity prepared with ultrasound and filled with MTA; F: apicoectomy with Er:YAG laser (400 mJ, 10 Hz) and treatment of apical surface with Nd:YAG laser (150 mJ, 10Hz); G: apicoectomy with CO2 laser (5W, CW/SP), root-end cavity prepared with ultrasound and filled with MTA; H: irradiation of apical end with CO2 laser (1 W, CW/CW); I: irradiation of apical end with Nd:YAG laser (150 mJ, 10 Hz). RESULTS: Dye penetration was found in all specimens at different rates, the lowest penetration occurring in groups C (16.20 percent), B (17.24 percent) and F (17.84 percent). CONCLUSIONS: Groups B, C and F represent the best technical sequences to perform endodontic surgery.

Ultrasonic tips in periradicular surgery

Technological advances have increased the rate of success of dental procedures. In periradicular surgery, the use of ultrasonic tips ensures high-quality root-end cavity preparations, enables the performance of a 90-degree apicoectomy, and removes larger amounts of contaminated material. The authors reviewed in vitro and in vivo studies in the literature and evaluated root-end cavities prepared with burs or ultrasonic tips using scanning electron microscopy.