Publications

Books and Chapters

• eBook Chapter: Postplacement oral care and prosthesis maintenance in patients with implant supported fixed complete denture. Implant supported fixed complete denture. ebook for www.FOR.org , leading author: Dr. Charles Goodacre, Summer 2018 (06/2018 - 09/2018)
• eBook Chapter: Framwork Fit, Accuracy, Porosity, And Mechanical Properties of Removable Partial Denture Alloys. RPD ebook for eHumanTM, leading author: Dr. Charles Goodacre, Spring 2017 (03/2017 - 06/2017)

Scholarly Journals--Published

• Success rate and strength of osseointegration of immediately loaded UV-photofunctionalized implants in a rat model. J Prosthet Dent.Soltanzadeh P, Ghassemi A, Ishijima M, Tanaka M, Park W, . . . Ogawa T. (2017). STATEMENT OF PROBLEM: Despite its clinical benefits, the immediate loading protocol might have a higher risk of implant failure than the regular protocol. Ultraviolet (UV) photofunctionalization is a novel surface enhancement technique for dental implants. However, the effect of photofunctionalization under loading conditions is unclear. PURPOSE: The purpose of this animal study was to evaluate the effect of photofunctionalization on the biomechanical quality and strength of osseointegration under loaded conditions in a rat model. MATERIAL AND METHODS: Untreated and photofunctionalized, acid-etched titanium implants were placed into rat femurs. The implants were immediately loaded with 0.46 N of constant lateral force. The implant positions were evaluated after 2 weeks of healing. The strength of osseointegration was evaluated by measuring the bone-implant interfacial breakdown point during biomechanical push-in testing. RESULTS: Photofunctionalization induced hydrophilic surfaces on the implants. Osseointegration was successful in 28.6% of untreated implants and 100% of photofunctionalized implants. The strength of osseointegration in successful implants was 2.4 times higher in photofunctionalized implants than in untreated implants. The degree of tilt of untreated implants toward the origin of force was twice that of photofunctionalized implants. CONCLUSIONS: Within the limit of an animal model, photofunctionalization significantly increased the success of osseointegration and prevented implant tilt. Even for the implants that underwent successful osseointegration, the strength of osseointegration was significantly higher for photofunctionalized implants than for untreated implants. Further experiments are warranted to determine the effectiveness of photofunctionalization on immediately loaded dental implants. (02/2017) (link)
• Effect of UV photofunctionalization on osseointegration in aged rats.Implant Dent. 2016 Dec;25(6):744-750. Objectives: This study evaluated the effect of photofunctionalization on osseointegration under the biologically adverse conditions of aging. Materials: First of all, bone marrow–derived osteoblastic cells from young (8 weeks old) and aged (15 months old) rats were biologically characterized. Then, the osteoblasts from aged rats were seeded on titanium discs with and without photofunctionalization, and assessed for initial cell attachment and osteoblastic functions. Titanium mini-implants, with and without photofunctionalization, were placed in the femur of aged rats, and the strength of osseointegration was measured at week 2 of healing. Periimplant tissue was examined morphologically and chemically using scanning electron microscopy and energy dispersive x-ray spectroscopy, respectively. Results: Cells from the aged rats showed substantially reduced biological capabilities compared with those derived from young rats. The cells from aged rats showed significantly increased cell attachment and the expression of osteoblastic function on photofunctionalized titanium than on untreated titanium. In addition, the strength of osseointegration was increased by 40% in aged rats carrying the photofunctionalized implants. Robust bone formation was observed around the photofunctionalized implants with strong elemental peaks of calcium and phosphorus, whereas the tissue around untreated implants showed weaker calcium and phosphate signals than titanium ones. Conclusion: These in vivo and in vitro results corroboratively demonstrate that photofunctionalization is effective for enhancing osseointegration in aged rats. (12/2016) (link)
• Enhancing osteoblast-affinity of titanium scaffolds for bone engineering by use of ultraviolet light treatment. Ishijima M, Soltanzadeh P, Hirota M, Tsukimura N, Ishigami T, Ogawa T. Biomedical Research. 2015;36(1):55-62 Ultraviolet (UV) treatment immediately prior to use is attracting attention as an effective surface conditioning method for titanium to improve osteoblast-affinity. The affinity of titanium to osteoblasts in two-dimensional plate culture has been well studied, but that in three-dimensional cultures remains unclear. Here, we examined the effect of UV treatment on titanium scaffolds, comprising micro-thin titanium fibers, used in bone engineering. Titanium scaffolds, with and without UV treatment, were seeded with rat bone marrow derived osteoblasts, and the number of cells attached to scaffolds and osteoblastic phenotype in the cultures were examined. UV treatment improved the wettability of scaffolds and significantly reduced the percentage of surface carbon. Along with these physicochemical changes in the scaffolds, cell attachment increased by a factor of 1.3 as compared to that of the untreated control. In addition, alkaline phosphatase activity and calcium deposition significantly increased by a factor of 2.3 and 2.0, respectively. Robust formation of mineralized structures consisting of clear peaks of calcium and phosphorus was observed in the UV-treated scaffolds. The observed increase in osteoblast affinity and capability of mineralized matrix formation indicates the potential use of UV-treated titanium scaffolds for bone engineering. (05/2015) (link)