RESUMO
Scientific backgrounds: Development of nanostructured biodegradable alloys has generated a great deal of interest in the recent years as they offer promising bioactive materials for reconstruction of bony defects following traumatic fractures or surgical excision of tumors. Objectives: The aim of the current study was to investigate the biocompatibility of Iron-Manganese -based alloys (Fe-Mn) with addition of copper (Cu), Tungsten (W) and cobalt (Co) to obtain 3 different alloys namely, Fe-Mn-Cu, Fe-Mn-W, and Fe-Mn-Co on normal oral epithelial cell line,and their possible anticancer effect on MG-63: osteosarcoma cell line. Materials and methods: The sulforhodamine B (SRB) assay was used to assess cell viability percentage of both cell lines after exposure to discs of the proposed experimental alloys. Moreover, the antibacterial effect of such alloys against Escherichia coli (E. coli) was tested using disc diffusion susceptibility (Kirby-Bauer method) and colony suspension method. Results: The cell viability percentage of oral epithelial cell line showed a significant increase in all the experimental groups in comparison to the control group. The highest percentage was observed in Fe-Mn-Co group, followed by Fe-Mn-W then Fe-Mn-Cu, at 24 and 72-h intervals, respectively. While the cell viability percentage of osteosarcoma cell line showed significant increase in all the experimental groups at 24-h intervals, it showed a significant drop in all the study groups at 72-h intervals. The lowest percentage was observed in Fe-Mn-Cu group, followed by Fe-Mn-W then Fe-Mn-Co. Moreover, all the examined study groups didn't show any inhibition zones against E. coli reference culture. Conclusions: The novel nanostructured biodegradable Fe-Mn-Cu, Fe-Mn-W, and Fe-Mn-Co metal alloys exhibit good biocompatibility on oral epithelial cell lines with the enhancement of cell proliferation in a time-dependent manner that favors bone regeneration. On the other hand, all the alloys manifested possible anticancer activity against MG-63: osteosarcoma cell line. Furthermore, our study sheds the light on the importance of Co, W and Cu as promising alloying elements. However, the antibacterial activity of the examined alloys is still questionable. Clinical relevance: The novel nanostructured biodegradable Fe-Mn-Cu, Fe-Mn-W, and Fe-Mn-Co metal alloys offer promising bioactive materials for reconstruction of bony defects following traumatic fractures or surgical excision of tumors, In addition, they could be excellent alternatives for undegradable or non-resorbable alloys that are commonly used. Moreover, they could be used as beneficial 3D printing materials to obtain patient-specific medical implants that favor bone regeneration in addition to manufacturing of plates and screws suitable for fracture fixation.
RESUMO
BACKGROUND: The purpose of this study was to investigate the effect of overjet size and the dento-alveolar compensation in subjects with normal class I molar relationship. MATERIALS AND METHODS: Lateral cephalometric head records of 59 Egyptian children (34 boys and 25 girls) aged 7.5 to 10.5 years with mean age of 8.69+/-0.73. All had normal class I type of occlusion. The sample was classified into four quartiles according to the overjet size and the cephalometric analysis was based on seven linear and eight angular measurements using a dental tracer programme. RESULTS: showed that, in spite of presence of high significant over jet size differences between the groups; there was no significant differences in all the studied parameters were found. Applying the least significant differences (LSD) test and coefficient correlations between the studied parameters clarifying that there was a significant differences in angular measurements (SN-AB, SN-Occl, I-I, I-ML, I-NB). CONCLUSION: during transitional dentition there was a sufficient dento-alveolar adaptation to growth changes in the saggittal jaw relation ship to attain normal class I type of occlusion. This compensation is pronounced in angular parameters and clustered in the lower arches particularly in incisal area.
