It has been found that the super-hydrophilicity of implant surfaces plays an important role for the initial attachment and subsequent behavior of cells. Super-hydrophilicity has been obtained by physical treatment (atmospheric-pressure plasma and UV treatment) as well as chemical treatment (blasting and acid-etching). However, the super-hydrophilicity rapidly decreases over time in air atmosphere. If the super-hydrophilicity after physical treatment can be sustained during long-term storage in water and osteogenesis on these super-hydrophilic surfaces is confirmed, this treatment is expected to be a promising method for clinical application as the disadvantage of chairside treatment is reduced. The present study evaluated the initial attachment, proliferation and differentiation of osteoblast-like cells on titanium surfaces that were stored in distilled water after various superhydrophilic treatments, and discussed the efficacy of long-term storage in water after super-hydrophilic treatment.
Commercially pure titanium discs were subjected to blasting and acid-etching, and the following treatments were performed : 1) stored in air atmosphere (As-Air) , 2) stored in distilled water (As-DW), 3) stored in distilled water after atmospheric-pressure plasma treatment of As-Air specimens (Plasma-DW) , and 4) stored in distilled water after UV treatment of As-Air specimens (UV-DW). The storage period was 1 month in all conditions. Surface morphology, wettability, and surface energy of these specimens were evaluated. Furthermore, mouse osteoblast-like cells MC3T3-E1 were cultured on these specimens, and then initial cell attachment, proliferation, alkaline phosphatase activity, and secretion of calcospherite were evaluated.
Though the As-Air specimens showed hydrophobicity, the As-DW, Plasma-DW and UV-DW specimens that were stored in distilled water showed super-hydrophilicity. Surface energy increased on all super-hydrophilic groups compared to the hydrophobic specimens. Initial cell attachment, proliferation, and alkaline phosphatase activity were enhanced more on super-hydrophilic groups than on the As-Air specimens. These properties showed no apparent differences in the super-hydrophilic groups. Secretion of calcospherite and collagen was confirmed on all specimens.
These results indicate that the storage in distilled water after physical treatment (atmospheric-pressure plasma and UV treatment) as well as chemical treatment (blasting and acid-etching) sustained the super-hydrophilicity, and enhanced the initial attachment, proliferation, and differentiation of osteoblast-like cells compared to specimens stored in air atmosphere, indicating that the method is promising for clinical application.
A 60-year-old male patient presented with a chief complaint of difficulty in chewing. The patient had been diagnosed as intranasal chondrosarcoma and underwent maxillectomy. The defect had been simultaneously reconstructed by re-vascularized fibular flap in another hospital 5 years earlier. There had been no recurrence of the problem since the last oncologic surgery. The initial panoramic radiograph revealed the absence of nasomaxillary buttress, bone resorption around the fibula, and native bone stumps associated with the periodontal involvement of the adjacent teeth. A maxillary complete denture was fabricated following the extraction of hopeless teeth. However, the patient decided to pursue implant treatment because of denture instability. Although additional reconstructive surgery was considered for development of the implant site, bone grafting in localized defects was chosen to eliminate the risk of injury to the anastomosed vessels. Platform-switched implants were selected because implants placed in sites reconstructed with fibular flaps are more susceptible to peri-implantitis. Guided implant surgery was performed to place five implants in the maxilla, with minimal mucoperiosteal flap elevation for three anterior implants and extensive periosteal elevation for two posterior implants to augment the implant sites and areas of bone loss with autogenous bone harvested from the mandibular ramus. A provisional restoration was performed 6 months after the implant surgery, followed by a period of observation. The final restoration was performed 14 months postoperatively. The patient has been followed up every 3 months for 4 years and 4 months. His postoperative course remains uneventful, with no bone fracture or resorption at the grafted sites and no signs of peri-implantitis.