著者

木村 英一郎 野村 智義 溝口 尚 吉成 正雄

出版者

公益社団法人 日本口腔インプラント学会

雑誌

日本口腔インプラント学会誌 (ISSN:09146695)

巻号頁・発行日

vol.27, no.1, pp.54-60, 2014-03-31 (Released:2014-04-20)

参考文献数

22

---

Fluoride-containing pastes for professional mechanical tooth cleaning (PMTC) have been frequently used during implant treatment. However, the influence of these pastes on the corrosion resistance of titanium implants is not well understood. The objective of this study was to clarify the influence of the pH of fluoride-containing paste on the corrosion resistance of commercially available pure titanium (cp-Ti). Commercially available PMTC pastes with neutral pH (6.8-7.4) and different fluorine concentration (400-980 ppm), acidulated phosphate fluoride (APF) paste (APF 9000A, fluorine concentration:9000 ppm, pH=3.7), and experimental acidic NaF paste (NaF900A, fluorine concentration:900 ppm, pH=4.0) were applied to polished cp-Ti disks (grade 2). After storing the specimens at 37℃ for 3 days in a humid atmosphere, the color difference was measured, and optical microscope and scanning electron microscope (SEM) observations of the Ti disks were performed. In addition, the amounts of Ti dissolved into the pastes were evaluated. Remarkable color differences were observed on the Ti disks coated with APF9000A and NaF900A pastes of ΔE*ab=12.0(±2.3) and 8.8(±1.4), respectively. In contrast, negligible color differences were observed on the other specimens with ΔE*ab ranging from 0.6 to 1.2. The optical microscopic and SEM observations revealed that the Ti disks coated with APF9000A and NaF900A pastes had roughened surface morphologies caused by pitting corrosion. In addition, noticeable amounts of Ti, 25.3(±6.2) and 8.6(±2.3) µg/cm2, from Ti disks coated with APF9000A and NaF900A pastes, respectively, were detected. Accordingly, the remarkable color differences of the APF9000A and NaF900A specimens were due to the roughening of the surface caused by corrosion of the Ti surface. These results indicate that fluoride-containing pastes with low pH may reduce the corrosion resistance of titanium, and so great care is required when using these fluoride-containing pastes for PMTC.