ABSTRACT
The aim of the study was to investigate the effects of piezosurgery in accelerating the movement of orthodontic alveolar bone tooth of rats and the expression mechanism of bone morphogenetic protein-2 (BMP-2). Adult male Wistar rats (n=30), with an age range of 14-15 weeks, and an average weight of 250±16 g were used. The animals were randomly divided into the control and observation groups. The rats in the control group were injected with 25-dihydroxyvitamin (1,25-dihydroxycholecalciferol) into their dental ligament. The rats in the observation group were placed with an orthodontic device between the first molar and central incisor in the maxillary. On the first day after animal treatment, piezosurgery stimulation was performed on the first molar in maxillary. The changes of the movement distance of the first molar and gum surface temperature on days 1, 3, 5, 7 and 14 were then compared. Immunohistochemical staining was performed to detect the expression of BMP-2 of periodontal tissue in the tension side of the first molar. Tooth movement distance in the observation group on days 5, 7 and 14 was significantly longer than that in the control group (p<0.05). The gum surface temperature of the observation group was elevated to some extent, peaking after 20 min. BMP-2 mRNA and protein levels in the observation group were significantly higher than those of the control group at days 3, 5, 7 and 14 (p<0.05). In conclusion, piezosurgery may significantly accelerate the movement of orthodontic alveolar bone tooth of rats and be associated with an increasing BMP-2 expression.
ABSTRACT
OBJECTIVE: To investigate the expression and function of osteogenic genes osterix (OSX) and runt-related transcription factor 2 (RUNX2) in the rat periodontal tissues under orthodontic force for the remodeling of the periodontal tissues. METHODS: 24 Wistar rats were randomly divided into 4 groups of orthodontic tooth movements for 1, 3, and 7 days (experimental groups) and control group (without orthodontic force). The expression of RUNX2 and OSX in the periodontal tissues was analyzed using real time PCR for mRNA and Western blot analysis for protein. The data were also analyzed for involvement of the two genes in signal pathways using bioinformatics tools. RESULTS: The mRNA levels of RUNX2 and OSX increased in the periodontal tissues after subjected to the orthodontic force for 1 to 7 days, with the highest level occurring at day 7. The relative expression levels of RUNX2 and OSX mRNA were 1.85 ± 0.12, 304 ± 0.06 and 4.16 ± 0.068, and 1.52 ± 0.09, 1.83 ± 0.03 and 2.56 ± 0.06 at day 1, 3 and 7, respectively. The results of Western blot analysis were consistent with the mRNA results. CONCLUSION: In orthodontic tooth movement, the expression of RUNX2 and OSX was upregulated as a result of external stimulation, suggesting that the two genes is involved in periodontal tissue remodeling and plays an important role in periodontal tissue remodeling.
Subject(s)
Core Binding Factor Alpha 1 Subunit/metabolism , Osteogenesis , Periodontium/metabolism , Tooth Movement Techniques , Transcription Factors/metabolism , Animals , Blotting, Western , Computational Biology , Core Binding Factor Alpha 1 Subunit/genetics , Male , Orthodontic Wires , Osteogenesis/genetics , Protein Interaction Maps , RNA, Messenger/genetics , RNA, Messenger/metabolism , Rats, Wistar , Real-Time Polymerase Chain Reaction , Reverse Transcriptase Polymerase Chain Reaction , Stress, Mechanical , Time Factors , Tooth Movement Techniques/instrumentation , Transcription Factors/genetics , Up-RegulationABSTRACT
OBJECTIVE: This study aims to explore the expression levels of ATF4 and RUNX and their interactions in periodontal tissue of the pressure side during orthodontic tooth movement. METHODS: A total of 72 SPF level male Sprague Dawley rats were used in this study, they were divided into 9 groups randomly and 8 rats in each group. The expression changes of ATF4 and RUNX2 in periodontal tissue of pressure side at different straining time point were detected with RT-PCR and Western blotting methods. The morphological changes of cells in the tissue samples were observed by HE staining. The data were analyzed with SPSS 19.0 software. RESULTS: The expression levels of ATF4 and RUNX2 increased during orthodontic tooth movement and were related with the movement time. They reached highest after straining for 24 h and began to decrease after straining for 12 d. CONCLUSIONS: The expression levels of ATF4 and RUNX2 in periodontal tissue can increase transiently induced by stress, which play a role in the process of osteogenesis and reconstruction of periodontal tissue during orthodontic tooth movement.
