Motoharu Miyamoto

Regenerative effect of basic fibroblast growth factor on periodontal healing in two‐wall intrabony defects in dogs

AIM The aim of the present study was to evaluate the effect of a basic fibroblast growth factor (bFGF) candidate treatment on periodontal healing in two-wall intrabony defects in dogs. MATERIALS AND METHODS Two-wall intrabony defects (5 x 5 x 5 mm) were created surgically on the distal and mesial sides of bilateral mandibular second and fourth premolars in four Beagle dogs. bFGF, enamel matrix derivative (EMD) and platelet-derived growth factor with beta-tricalcium phosphate (PDGF/beta-TCP) treatments, and sham-surgery (OFD) were rotated among the four defects in each animal, EMD and PDGF/beta-TCP serving as benchmark controls. The animals were euthanized for radiographic and histologic evaluation at 8 weeks. RESULTS Bone formation was significantly greater in the bFGF group (4.11 +/- 0.77 mm) than in the EMD (3.32 +/- 0.71 mm; p<0.05) and OFD (3.09 +/- 0.52 mm; p<0.01) groups. The EMD (4.59 +/- 1.19 mm) and PDGF/beta-TCP (4.66 +/- 0.7 mm) groups exhibited significantly greater cementum regeneration with periodontal ligament-like tissue than the OFD group (2.96 +/- 0.69 mm; p<0.01). No significant differences were observed between the bFGF and the PDGF/beta-TCP groups in any of the histometric parameters. CONCLUSIONS The candidate bFGF treatment supported periodontal regeneration comparable with that of established benchmarks: EMD and PDGF/beta-TCP.

The association of periodontal disease with oral malodour in a Japanese population

AIM The purpose of this study was to evaluate the association between oral malodour and periodontal disease, and to determine the effect of periodontal therapy on oral malodour. MATERIALS AND METHODS Oral malodour parameters, including volatile sulphur compound (VCS) measurement, methyl mercaptan/hydrogen sulphide ratio by gas chromatography, organoleptic testing, tongue coating score, and periodontal parameters were evaluated in 823 patients complaining of oral malodour. Amongst these patients, 89 with oral pathogenic halitosis received tongue cleaning and periodontal therapy. Oral malodour and periodontal parameters were measured at baseline and after treatment. RESULTS Amongst 823 patients, 102 were diagnosed with gingivitis and 721 with periodontitis. VCS levels and periodontal parameters increased according to the severity of oral malodour. Organoleptic testing significantly correlated with periodontal probing depth and a percentage of periodontal pocket depth ≥4mm (r=0.40 and 0.39 respectively). There were significant correlations between methyl mercaptan/hydrogen sulphide ratio and periodontal parameters. Significant decrease in oral malodour and periodontal parameters in 89 patients with oral pathogenic halitosis was also observed after periodontal treatment. CONCLUSIONS Oral malodour is associated with periodontal disease, and periodontal therapy combined with tongue cleaning is beneficial for oral pathogenic halitosis.

Proliferation of Osteoblast-Like Cells on Zirconia/Alumina Nanocomposite

The aim of this study was to evaluate the biocompatibility with the proliferation of osteoblast-like cell (MC3T3-E1) on zirconia/alumina nanocomposite (NANOZR) in comparison to yttria stabilized zirconia (3Y-TZP) and titanium (Ti). Cellular proliferations after 1-, 3-, 6-, and 9-day incubation were calculated from the measurement of the MTT activities of the proliferated cell and were analyzed by two-way ANOVA. Time-dependent proliferation of MC3T3-E1 in all the sample was observed in all three materials with culture days. However, these were no significant differences in the proliferation between three kinds of material, indicating all the materials have a similar-good biocompatibility.

Early Cellular Responses of Osteoblast-Like Cells on Acid-Etching and Alkaline Treated Titanium

The effects of four surface modification (acid-etching, alkaline treatment, acid-etching /alkaline treatment, and sandblasting) of commercially pure titanium (cpTi) on the early cellular responses of osteoblast-like MC3T3-E1 cells were investigated. MTT assay was used to measure the levels of cell attachment to the different surface specimens after 1-, 2-, and 3-hr cell incubation. All data were submitted to two-way analysis of variance. Cell morphology was observed by scanning electron microscopy (SEM). Results showed that initial adhesion of osteoblast-like cells was independent on the surface of cpTi modified with different method.

Apatite Coating on Ti Surface Using Alternate Soaking Process

An apatite coating by an alternate soaking was undertaken on commercially pure titanium (cpTi) treated with concentrated acid and alkaline solutions. X-ray diffraction (XRD) patterns indicated that the diffraction peak intensities assigned to hydroxyapatite (HAp) increased with the reaction cycle. Fourier transform infrared spectroscopic study (FTIR) showed similar results with XRD. Scanning electron micrographs (SEM) of the deposits showed no observable change after the vacuum firing. It was confirmed that the reaction cycle greatly affected on the deposited amount of apatite on cpTi plates using the alternate soaking and the vacuum firing erased TiH2 formed during the acid etching, but was irrelevant to the crystallinity of the apatite.

In Vitro Evaluation of Hydroxyapatite-Containing Glass Coating on Zirconia

The aim of this study was to investigate the response of osteoblast-like cells (MC3T3-E1) to the surface of hydroxyapatite-containing glass coating on zirconia (HA-G-Zr) in comparison to yttria stabilized zirconia (Y-TZP). The MC3T3-E1 cells were cultured on HA-G-Zr and Y-TZP specimens in 24-well tissue culture plates. Surface properties were evaluated by X-ray diffractometry, Fourier tranfer infrared microscopy (FT-IR) and scanning electron microscopy (SEM). Cell proliferation in each well was measured by MTT assay. Cell morphology was observed by SEM. Cell differentiation was evaluated by alkaline phosphatase (ALP) activity and osteocalcin levels. After the glass coating on Y-TZP, X-ray diffraction peaks due to hydroxyapatite (HA) were observed clearly. HA-G-Zr appeared on surface of uneven and roughened state, wherein microcracks on the microns in width and many voids of several microns in size were present. Time-dependent proliferation and differentiation of MC3T3-E1 cells were found in all the specimens. MC3T3-E1 cells on HA-G-Zr plates showed higher differentiation than Y-TZP. These results demonstrated that HA-G-Zr showed better cellular biocompatibility than Y-TZP.