Osteogenic differentiation of follicular stem cells on nano-Saghez scaffold containing BMP2.

BACKGROUND: Bone tissue is one of the tissues that are capable of self-regeneration. However, bone self-regeneration is defeated in the case of broad lesion of bone structure. Isolated stem cells from wisdom tooth follicles can potentially differentiate into ectodermal and mesodermal cells. Saghez is a natural substance that has been extracted from Pistacia terebinthus with unique features, such as high temperature and mechanical stability, adhesive structure, biocompatibility, and anti-neoplastic properties. METHODS: In this study, Saghez-encapsulated BMP2 was applied as a scaffold for wisdom tooth follicle stem cell differentiation into the osteocyte. A total of three wisdom tooth follicles were obtained for stem cell isolation. For verification of differentiation of the isolated stem cells into osteocyte and adipocyte, Oil Red and Alizarin staining were applied, respectively. Moreover, mesenchymal stem cells were distinguished by profiling their cell surface markers, includingCD73, CD90, CD44, and CD105, by flow cytometry. Saghez scaffold loaded with BMP2 factor was prepared using sol-gel method. Four experimental groups were considered in this study: cells seeded on BMP2 encapsulated in Saghez scaffold, Saghez scaffold, osteogenic medium, and DMEM medium. RESULTS: Mechanical properties of Saghez scaffold, including tensile Young's modulus, ultimate tensile stress, compression Young's modulus, and complex shear modulus, were 19 MPa, 32 MPa, 0.42 MPa, and 0.9 MPa, respectively. The porosity of the scaffold was 70-140 µm, and the percentage of porosity was 75-98%. The results of flow cytometry studies indicated that CD44, CD73, CD90, and CD105 were positively expressed on the membrane of the tooth follicles' stem cell. The results indicated that the rate of differentiation of the follicle stem cells into osteocyte was the highest in the Saghez-BMP2 scaffold containing differentiation medium groups. These findings were verified by morphological studies, osteoblast and osteocalcin gene and protein expression investigations, and alkaline phosphatase activity measurement. The highest osteopontin and osteocalcin genes expression levels (1.7 and 1.9) were seen in positive control, followed by DMEM + differentiation factor (1.5 and 1.6), scaffold + BMP2 (1.2 and 1.4), DMEM + stem cell (1 and 1) and scaffold (0.4 and 0.5), and negative control respectively. CONCLUSION: This study provides a novel system for differentiation of the stem cell into osteocytes. The results of this study suggest that loaded BMP2 in Saghez scaffold possibly acts as an osteocyte differentiator factor.

Zimmermann-Laband syndrome: Clinical and cytogenetic study in two related patients.

BACKGROUND: Zimmermann-Laband Syndrome (ZLS) is an extremely rare autosomal dominant congenital disorder. It is a craniofacial malformation syndrome with predominant intraoral involvement consisting of gingival fibromatosis diffusion in early development. The molecular basis of ZLS is still unknown. Although familial aggregation with different inheritance patterns is detected in ZLS patients, most of the cases are sporadic. MATERIAL AND METHODS: We report on two sibling patients with clinical manifestations of ZLS. Blood samples of both patients were obtained in EDTA-tubes followed by performing cytogenetic study using Cyto2.7M array. Analysis of the copy number was performed using the Chromosome Analysis Suite Software (version 1.0.1, annotation file na 30, Affymetrix) and interpreted with recourse to the UCSC genome browser (http://genome.ucsc.edu/; Human Mar. 2006NCBI Build 36.1/hg18 assembly). RESULTS: The array analysis revealed overlapping regions of chromosomal aberrations in both patients. We detected a 258-kb deletion at 3q13.13, a 89-kb duplication at 1q25.2 as well as two 67-kb duplications at 1p12 and 19q12. These altered regions do not contain any known genes and protein-coding sequences. CONCLUSIONS: In conclusion, the findings of this report revealed new chromosomal aberrations, including a deletion at 3q13.13 and duplications at 1q25.2, 1p12 and 19q12, in the two patients with ZLS. Such findings indicate that whole genome screening for genomic rearrangements is fruitful in typical and atypical patients with ZLS. Key words:Zimmermann-Laband syndrome, cytogenetic array, whole genome screening, chromosomal aberration, gingival fibromatosis.

Effect of Pulpotomy Procedures With Mineral Trioxide Aggregate and Dexamethasone on Post-endodontic Pain in Patients with Irreversible Pulpitis: A Randomized Clinical Trial.

OBJECTIVE: Endodontic post-treatment pain continues to be one of the main problems encountered by dental professionals. Therefore, pain control during and after endodontic treatment is one of the most important issues in endodontics. The purpose of this clinical trial was to compare postoperative pain relief achieved with dexamethasone (DEX) and mineral trioxide aggregate (MTA) used as pulp coverage after pulpotomy in human molars with irreversible pulpitis. METHODS: This prospective double-blind study was conducted on 54 patients complaining of dental pain due to irreversible pulpitis. The standard pulpotomy procedure was performed by the same dentist in all patients. At the time of the cotton pellet placement, patients were randomly divided into three groups: those in whom a sterile dry cotton (DC) pellet was used, patients treated with a cotton pellet soaked in MTA, and those who were treated with a cotton pellet soaked in DEX. After completion of the treatment, patients received rescue medication every 6 hours for the first day. Postoperative pain was assessed at 6-hour intervals for 24 hours, and then every day until day 7 using a visual analog scale. RESULTS: In general, patients treated with MTA suffered the lowest levels of pain at all time intervals. Post-pulpotomy pain was significantly reduced at 18 and 24 hours and from days 2 to 7 post-treatment in the MTA group. DEX lowered the pain level more than the DC pellet. However, the differences observed in the mean pain scores of the DEX and DC pellet groups at all-time intervals were not statistically significant. CONCLUSION: Pulpotomy procedures can reduce pain related irreversible pulpitis. Pulpotomy with MTA-soaked cotton pellet significantly reduces pain intensity in patients with irreversible pulpitis.