ABSTRACT
@#The titanium exfoliation level during dental implant installation has not yet been available. The present study aims to confirm the presence of titanium exfoliation in different implant surfaces throughout the installation and identify the association between insertion torque and surface abrasion. Three different implant surfaces were assigned to low and high insertion torque groups. The implants were installed into porcine bone blocks. Then, the surrounding bone at the ostomy site was analysed for the titanium exfoliation using an inductively coupled plasma mass spectrometry. The low and high insertion torques were 30 Ncm and 58 Ncm, respectively. The average titanium content from all samples was 4.9 ± 2.7 μg. Anodised implant released significantly less titanium compared to others (p < 0.05). All implants released titanium indifferently compared to low and high insertion torques (p > 0.05). Within the limitation of the present study, anodised implant released the least amount of titanium exfoliation. The insertion torque was not associated with titanium exfoliation.
ABSTRACT
PURPOSE: The intracellular mechanisms that lead to periprosthetic osteolysis including impaired bone forming activity of osteoblast remain incompletely characterized. To determine the possibility that Ti-particles play a role to regulate Wnt/beta-catenin signaling pathway in impaired osteogenesis, we analyzed the stability of beta-catenin and the transcriptional changes of regulators for Wnt/beta-catenin signaling pathway in MC3T3-E1 osteoblast cells. MATERIALS AND METHODS: Ti-particles were prepared by sterilizing and counted on the microscopy. Transcriptional changes of OPG, RANKL, LRP5, LRP6, DKK1 and sFRP2 were determined by real-time RTPCR. Protein level of beta-catenin and GSK3beta was detected using Western blotting and immunofluorescence staining. RESULTS: After 4 hours of treatment of Ti-particles, OPG/RANKL mRNA ratio was significantly decreased. And also, decreased protein levels of beta-catenin and phospho-GSK3beta were detected. Using immunofluorescence stain, it was confirmed that Ti-particles suppressed nucleus staining of beta-catenin induced by Wnt3a conditioned medium. The results of real-time RT-PCR showed reduced level of LRP5 and LRP6 transcripts, and induced level of DKK1 and sFRP2 transcripts by challenging of Ti-particles CONCLUSION: Our report suggests that Ti-particles may play a crucial role in the regulation of Wnt/beta-catenin signaling pathway in osteoblast through the transcriptional changes of membrane receptors and extracellular inhibitors for Wnt.
Subject(s)
beta Catenin , Blotting, Western , Culture Media, Conditioned , Fluorescent Antibody Technique , Glycogen Synthase Kinase 3 , Membranes , Microscopy , Osteoblasts , Osteogenesis , Osteolysis , RNA, Messenger , TitaniumABSTRACT
[Objective]Titanium particle induced mouse calvarial osteolysis model was used to investigate the effects and mechanisms of sodium ibandronate on osteolysis.[Methods]Twenty-four Kunming species mice were randomly divided into 4 groups,6 in each group.Control group received sham operation.Titanium particle group received 30 mg titanium particle implantation onto the calvariae.One unit sodium ibandronate group and 10 units sodium ibandronate group received 10 mg and 100mg sodium ibandronate ip injection separately on the next day of titanium particles implantation.Ten days later,mice calvariae were harvested for pathology analysis.[Results]In control group osteolysis area was(0.070?0.009)mm2 and osteolysis was not apparent.In titanium particle group osteolysis area(0.369?0.050)mm2 was bigger than that of control group(P