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Daming WU, Zhijuan TANG, Guangdong ZHANG, Weihong LIU
2011 年 30 巻 5 号 p.
569-575
発行日: 2011年
公開日: 2011/10/08
[早期公開] 公開日: 2011/09/23
ジャーナル
フリー
Percentage of gutta-percha-filled area (PGFA) was used to investigate the sealing ability of GuttaFlow. A total of 80 mandibular first premolars with single canal were randomly divided into 4 Groups (
n=20) according to root canal filling technique and/or material — Group1: cold lateral condensation technique; Group 2: continuous wave condensation technique; Group 3: GuttaFlow; Group 4: GuttaFlow and accessory gutta-percha cones without lateral condensation. The PGFA values of Groups 3 and 4 were significantly higher than those of Groups 1 and 2 (
p<0.05), but there were no significant differences between Group 3 and Group 4 (
p>0.05). It was concluded that GuttaFlow provided superior sealing ability, such that accessory gutta-percha cones became unnecessary when filling root canals with GuttaFlow.
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Toru NIKAIDO, Chiaki ICHIKAWA, Na LI, Tomohiro TAKAGAKI, Alireza SADR, ...
2011 年 30 巻 5 号 p.
576-582
発行日: 2011年
公開日: 2011/10/08
[早期公開] 公開日: 2011/09/23
ジャーナル
フリー
This study aimed at evaluating the effect of functional monomers in all-in-one adhesive systems on formation of acid-base resistant zone (ABRZ) in enamel and dentin. Experimental adhesive systems containing one of three functional monomers; MDP, 3D-SR and 4-META were applied to enamel or dentin surface and light-cured. A universal resin composite was then placed. The specimens were subjected to a demineralizing solution (pH 4.5) and 5% NaClO for acid-base challenge and then observed by SEM. The ABRZ was clearly observed in both enamel and dentin interfaces. However, enamel ABRZ was thinner than dentin ABRZ in all adhesives. Morphology of the ABRZ was different between enamel and dentin, and also among the adhesives. Funnel-shaped erosion was observed only in the enamel specimen with the 4-META adhesive. The formation of enamel/dentin ABRZ was confirmed in all adhesives, but the morphology was influenced by the functional monomers.
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Chikage KATO, Masaya SUZUKI, Koichi SHINKAI, Yoshiroh KATOH
2011 年 30 巻 5 号 p.
583-597
発行日: 2011年
公開日: 2011/10/08
[早期公開] 公開日: 2011/09/23
ジャーナル
フリー
The studies so far conducted by our colleagues in relation to dental pulp capping using adhesive resins revealed that the adhesive resins are useful for capping exposed pulps but are a little slower to take effect on the injured pulp tissue during the initial stage: up to 90-days after pulp exposure, compared with calcium hydroxide and its preparations. In the present study, an experimentally developed adhesive resin system was applied in direct pulp capping and restoration and the healing process was examined histopathologically and immunohistochemically. The resin system was manufactured with calcium phosphate added into the bonding material for the purpose of accelerating the healing process. The largest amount of reparative dentin was formed by SE5 (whitlockite 5 wt%), followed by SE9 (hydroxyapatite 5 wt%, whitlockite 5wt%), SE1 (hydroxyapatite 5 wt%), and SE2 (hydroxyapatite 10 wt%). Generally, it could be said that the experimental groups using whitlockite and hydroxyapatite had the tendency to produce a larger amount of reparative dentin.
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Lamia MUTLU-SAGESEN, Gulfem ERGUN, Erdem KARABULUT
2011 年 30 巻 5 号 p.
598-610
発行日: 2011年
公開日: 2011/10/08
[早期公開] 公開日: 2011/09/23
ジャーナル
フリー
The aim of this
in vitro study was to assess the effect of pH changes on ion release of metal-ceramic dental casting alloys. Samples from four commercially available alloys (Wirobond C, Wiron 99, Rematitan CP-Ti grade 1, and PontoStar) were prepared and polished. Ion release of alloys subjected to three different pH media (artificial saliva of pH 2.3, pH 6.5 and 0.9% saline solution of pH 7.3) for periods of 7, 15, 30, and 60 days were assessed by means of atomic absorption spectroscopy. Microscopic changes on surfaces of metallic samples before and after immersion were compared by scanning electron microscopy. ANOVA was used for statistical analysis of results. For all ions, pH and period interactions were statistically significant: highest amount of ion release occurred after 60 days of immersion regardless of pH value. For every alloy, ion release results were highest in artificial saliva of pH 2.3 and lowest in 0.9% saline solution. It was concluded that ion release from alloys was pH-dependent.
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Satoshi YAGI, Zutai ZHANG, Yoshiteru AIDA, Yasuhiro HOTTA, Yukimichi T ...
2011 年 30 巻 5 号 p.
611-615
発行日: 2011年
公開日: 2011/10/08
[早期公開] 公開日: 2011/09/23
ジャーナル
フリー
In this study, different glasses were investigated to improve reusable investments. Borosilicate glass (BSG) powder and soda-lime glass (SLG) powder were prepared by milling broken beakers and microscope slides, respectively, and used in experimental investments (I-BSG, I-SLG) by blending glass powder (10wt%) with cristobalite (90wt%). Some properties and casting fits were evaluated with commercial gypsum-bonded investment as the control. Both BSG and SLG were mainly composed of Si, but SLG had a large Ca content. The glass transition temperatures were approximately 800°C (BSG) and 700°C (SLG). Experimental investments with heating showed the significantly (
p<0.05) higher expansion than that of the control. The compressive strength of I-SLG was higher than that of I-BSG, and increased with temperature. The MOD inlay obtained from I-SLG had a significantly smaller gap than that from I-BSG, and was comparable to the control. These results suggest SLG could be applied clinically as a reusable dental investment.
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Kunio IKEMURA, Yoshiyuki JOGETSU, Kazuya SHINNO, Toshiyuki NAKATSUKA, ...
2011 年 30 巻 5 号 p.
616-625
発行日: 2011年
公開日: 2011/10/08
[早期公開] 公開日: 2011/09/23
ジャーナル
フリー
This study investigated the bonding effectiveness of newly designed self-etching adhesives to four types of adherends —enamel, dentin, zirconia, and gold (Au) alloy. Five experimental adhesives were prepared, which contained 3.0–5.0 wt% 6-methacryloyloxyhexyl phosphonoacetate (6-MHPA) or 6-methacryloyloxyhexyl 3-phosphonopropionate (6-MHPP), 3.0 wt% 4-acryloyloxyethoxycarbonylphthalic acid (4-AET) or 17.0 wt% 4-methacryloyloxyethoxycarbonylphthalic acid (4-MET), 0–0.5 wt% 6-methacryloyloxyhexyl 6,8-dithiooctanoate (6-MHDT) or 10-methacryloyloxydecyl 6,8-dithiooctanoate (10-MDDT), and varying contents of Bis-GMA, dimethacrylate monomers, water, acetone, and a photoinitiator system. After 2,000 times of thermal cycling, shear bond strengths (SBSs) between a resin composite (Beautifil II, Shofu Inc., Japan) and the four adherends, bonded using the experimental adhesives, were measured at 1.0 mm/min. No statistically significant differences in SBS for bonding to ground enamel, dentin, sandblasted zirconia and Au alloy (
p>0.05) were found between experimental adhesives which contained 6-MHPA and/or 6-MHPP, 4-MET or 4-AET, 6-MHDT and/or 10-MDDT, Bis-GMA, and dimethacrylates. An adhesive layer of less than 5.0 μm thickness, by scanning electron microscopy observation, revealed strong adhesion to the four adherends. Therefore, the newly designed multi-purpose, self-etching adhesive strongly adhered to all the four adherend materials tested.
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Hiromi MARUYAMA, Yasuhiro NISHI, Kazunori TSURU, Eiichi NAGAOKA
2011 年 30 巻 5 号 p.
626-634
発行日: 2011年
公開日: 2011/10/08
[早期公開] 公開日: 2011/09/23
ジャーナル
フリー
The purpose of this study was to design an optimum glass fiber-reinforced composite (FRC) clasp. Three-dimensional finite element models were constructed of FRC circumferential clasp arms and an abutment tooth. The basic clasp arm was half-oval, without a taper, 2.60 mm wide and 1.30 mm thick. Four modified clasp arms were prepared by changing the width or thickness of the basic clasp (width/thickness: 2.60 mm/0.65 mm, 2.60 mm/1.95 mm, 1.30 mm/1.30 mm, and 3.90 mm/1.30 mm). Forced displacements of 5 mm in the removal direction were applied to the nodes at the base of the clasp arm. The retentive forces and maximum tensile stresses of the five FRC clasp arms ranged from 1.00–16.30 N and from 58.9–151 MPa, respectively. Results showed that an optimum FRC clasp was a circumferential clasp with 2.60 mm width and 1.30 mm thickness, which had sufficient retentive force and low risk of tensile failure.
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Yoshiyuki SAKAI, Hidekazu TAKAHASHI, Naohiko IWASAKI, Yoshimasa IGARAS ...
2011 年 30 巻 5 号 p.
635-641
発行日: 2011年
公開日: 2011/10/08
[早期公開] 公開日: 2011/09/23
ジャーナル
フリー
This study evaluated the effect of surface roughness and tapered angle of cone crowns on retentive force (RF). Cone crowns from Ti-6Al-7Nb alloy with a tapered angle of 4, 5, or 6° were fabricated using a milling machine and a finishing machine to produce a smooth surface. Cone crowns of 6° with a rough surface were also prepared. The RF during 1,000 cycles of insertion/separation was recorded. The first RF of the 6° cone crowns was 24.2–27.7 N, and the surface roughness was not significant. The RF of all specimens decreased at 100 cycles, then those of inner and outer crowns with the same roughness remained unchanged, but those of different roughnesses increased with number of cycles. The RF of cone crowns with a smaller tapered angle was significantly greater than with a larger angle at any measured cycles.
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Chiyako RYU, Yasuhiro NAMURA, Takashi TSURUOKA, Tomohiko HAMA, Kaori K ...
2011 年 30 巻 5 号 p.
642-647
発行日: 2011年
公開日: 2011/10/08
[早期公開] 公開日: 2011/09/23
ジャーナル
フリー
We experimentally produced an easily debondable orthodontic adhesive (EDA) containing heat-expandable microcapsules. The purpose of this
in vitro study was to evaluate the best debondable condition when EDA was used for ceramic brackets. Shear bond strengths were measured before and after heating and were compared statistically. Temperatures of the bracket base and pulp wall were also examined during heating. Bond strengths of EDA containing 30 wt% and 40 wt% heat-expandable microcapsules were 13.4 and 12.9 MPa, respectively and decreased significantly to 3.8 and 3.7 MPa, respectively, after heating. The temperature of the pulp wall increased 1.8–3.6°C after heating, less than that required to induce pulp damage. Based on the results, we conclude that heating for 8 s during debonding of ceramic brackets bonded using EDA containing 40 wt% heat-expandable microcapsules is the most effective and safest method for the enamel and pulp.
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Masafumi KIKUCHI, Masatoshi TAKAHASHI, Yukyo TAKADA
2011 年 30 巻 5 号 p.
648-654
発行日: 2011年
公開日: 2011/10/08
[早期公開] 公開日: 2011/09/23
ジャーナル
フリー
The purpose of this study was to establish a geometric design method for the occlusal outlines of complex inlay cavities as a continuation study of a previous design method for simple class I inlay cavity. A method for extending the occlusal outline to the buccal or lingual groove and to three preparation types of the proximal portions of class II inlay cavities —namely, straight line preparation, sweeping curve preparation, and reverse curve preparation— was investigated. To ensure the smoothness of the occlusal outline, a Bézier curve was introduced in the design. A minimal number of control points for the curve was applied to define each preparation type. The design method was experimentally applied to mandibular and maxillary first molars. Smooth outlines of the complex inlay cavities in the molars with tool accessibility throughout the cavities were achievable by using the present method.
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Hamid NURROHMAN, Toru NIKAIDO, Alireza SADR, Tomohiro TAKAGAKI, Shuzo ...
2011 年 30 巻 5 号 p.
655-663
発行日: 2011年
公開日: 2011/10/08
[早期公開] 公開日: 2011/09/23
ジャーナル
フリー
The purpose of this study was to investigate bond durability of MMA-based adhesives to root dentin in a simulated complete vertical root fracture (CVRF). The fractured fragments of human premolar root were reattached using Super-Bond C&B (SB; Sun Medical), M-Bond or M-Bond II (MB or MB II; Tokuyama Dental). After storage for 1 day, 1 month, 6 months and 1 year, the reattached specimens were subjected to microtensile bond strength (μTBS) test at cervical and apical regions. Results showed that μTBS was significantly higher to cervical dentin than to apical dentin in MB and MB II, but not SB (
p<0.05). Significant decrease in μTBS was found for MB and MB II after 1 year, whereas no significant difference was found for SB (
p<0.05). Analysis of failure mode by SEM indicated differences over time. In conclusion, significant differences were found in the regional bond durability among MMA-based adhesives used to restore CVRF, that may lead to different clinical performances.
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Takehiro MASUDA, Ken MIYAZAWA, Naoya UEDA, Yuki HATA, Tatsushi KAWAI, ...
2011 年 30 巻 5 号 p.
664-671
発行日: 2011年
公開日: 2011/10/08
[早期公開] 公開日: 2011/09/23
ジャーナル
フリー
For the development of new orthodontic elastic material, 1-butanol was added to PEMA-TA/HX resin. In the present study, basic experiments to reveal the mechanical properties of the materials were conducted. FT-IR spectroscopy showed that addition of 1-butanol did not cause any chemical changes to the PEMA-TA/HX resin. After addition of 1-butanol to PEMA-TA/HX resin, the modulus of elasticity, instantaneous modulus elasticity, retarded elasticity and viscosity were lowered in a concentration-dependent manner, whereas the elastic strain was increased in a concentration-dependent manner. Moreover, on the application of heat a shape-memory effect was observed. These results suggest that the modulus of elasticity of this material can be adjusted. Additionally, this material has the ability to restore force as a function of its shape-memory effect in cases of plastic deformation at the insertion of appliances. This new orthodontic elastic material has the potential to be clinically effective in orthodontic treatment.
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Kenji ARITA, Aimi YAMAMOTO, Yukari SHINONAGA, Keiko HARADA, Yoko ABE, ...
2011 年 30 巻 5 号 p.
672-683
発行日: 2011年
公開日: 2011/10/08
[早期公開] 公開日: 2011/09/23
ジャーナル
フリー
The aims of this study were to improve the mechanical and chemical properties of conventional restorative glass ionomer cement (GIC) by adding hydroxyapatite (HAp) preparations with different characteristics, and to investigate the underlying reaction mechanisms. Fuji IX GP® was used as the control GIC. The experimental GICs consisted of four HAp-particles with different characteristics added at 8 mass% to Fuji IX-powder. All cements were prepared by mixing with Fuji IX-liquid (P/L=3.6). Four HAp-particles were analyzed, and then the mechanical strengths and the fluoride-ion- release-recharge-behaviors of five GIC groups were evaluated. The results of this study demonstrate that the addition of HAp particles with highly reactive properties such as high specific surface area can enhance the flexural strength and fluoride ion release properties of conventional restorative GIC. Our results further indicate that HAp functions as an adsorbent and an ion exchangeable agent, resulting in improved mechanical and chemical properties of GIC.
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Pattapon ASVANUND, Steven M. MORGANO
2011 年 30 巻 5 号 p.
684-690
発行日: 2011年
公開日: 2011/10/08
[早期公開] 公開日: 2011/09/23
ジャーナル
フリー
The purpose of this study was to investigate stress developed by a combination of a stainless steel post or a fiber-reinforced resin post with a silver amalgam core or a composite resin core. Two-dimensional photoelastic models were used to simulate root dentin. Posts (ParaPost XT and ParaPost-FiberWhite) were cemented with a luting agent (RelyX Unicem). Silver amalgam cores and composite resin cores were fabricated on the posts. Complete crowns were fabricated and cemented on the cores. Each model was analyzed with 2 force magnitudes and in 2 directions. Fringe orders were recorded and compared using ANOVA (
p=0.05) and the Scheffe’s test. With vertical force, no stress differences occurred among the 4 groups (
p=0.159). With a 30-degree force, there was stress differences among the 4 groups (
p<0.001). The combination of a fiber-reinforced post and composite resin core could potentially reduce stresses within the radicular dentin when angled loads are applied.
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Masayuki UCHIMARU, Takako SAKAI, Ryoji MOROI, Susumu SHIOTA, Yukie SHI ...
2011 年 30 巻 5 号 p.
691-699
発行日: 2011年
公開日: 2011/10/08
[早期公開] 公開日: 2011/09/23
ジャーナル
フリー
This study examined the antimicrobial/antifungal ability of a tissue conditioner containing a photocatalyst for
Escherichia coli,
Streptococcus mutans,
Staphylococcus aureus and
Candida albicans. The photocatalyst was mixed with tissue conditioners powders at concentrations of 0, 10, 15, and 20 wt%. Tissue conditioners powders containing a photocatalyst were mixed with liquid to make test specimens. Test specimens inoculated by each microorganism were irradiated by ultraviolet light for 0-, 2- and 4 hours. The antimicrobial/antifungal effects were evaluated by the CFU technique. The CFU values of each microorganism for tissue conditioners containing a photocatalyst showed significant decrease following UV-irradiation. The improvement in antimicrobial/antifungal effects was concomitant with the increase of the mixing ratio and the irradiation time. Therefore, the results indicated that tissue conditioners containing a photocatalyst might have photocatalytic ability.
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Nélia ALBERTO, Lídia CARVALHO, Hugo LIMA, Paulo ANTUNES, ...
2011 年 30 巻 5 号 p.
700-706
発行日: 2011年
公開日: 2011/10/08
[早期公開] 公開日: 2011/09/23
ジャーナル
フリー
The impact of five different water/powder (w/p) ratios in the characterization of high strength dental stone was evaluated, since the recommendations of the gypsum’ manufacturers are not always correctly followed by the dental prosthesis technicians. Fiber Bragg grating (FBG) sensors were used to measure the setting expansion and temperature variation which occurred during the setting reaction for each w/p ratio, as well as the thermal expansion coefficient. Thick mixtures with low w/p ratios had more crystals impinging upon each other during crystal growth, resulting in more expansion and more heat released. This thermal behavior was only achieved to w/p ratios within the manufacturer-recommended mixing ratio range. The results also revealed the existence of boundary condition; this corresponding to the limit of the mixing ratio recommended by the gypsum’ manufacturer. Data provided in this study are particularly important for dental technicians with a view to attaining the best results in accuracy of fit for their prosthetic works.
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Soichiro HAMAJIMA, Tatsuhide HAYASHI, Yamato SATO, Keisuke SASAKI, Tat ...
2011 年 30 巻 5 号 p.
707-716
発行日: 2011年
公開日: 2011/10/08
[早期公開] 公開日: 2011/09/23
ジャーナル
フリー
The aim of this study was to develop a new cell transplantation technique for osteoanagenesis at bone defect sites. Polyvinylidene chloride (PVDC) film was evaluated because of its good biocompatibility and flexibility. We used this film as both a cell scaffold and a barrier membrane. Initially, the cell compatibility of the PVDC film for fibroblast-like cells and osteoblast-like cells was confirmed. Subsequently, bone marrow cells were obtained from rats and cultured on PVDC films in two kinds of medium. The PVDC films with bone marrow-derived mesenchymal stem cells (MSCs) were then applied to critical-sized bone defects in the calvarial bone of rats. After the transplantation, the surgical sites were dissected out and evaluated by soft X-ray radiography, micro-CT analysis and histological examinations. The bone marrow-derived MSC-transplanted rats showed greater bone regeneration than the control rats. Therefore, PVDC film is considered to be useful as a scaffold for bone regeneration.
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Duck-Su KIM, Sang Hyuk PARK, Gi-Woon CHOI, Kyoung-Kyu CHOI, Sun-Young ...
2011 年 30 巻 5 号 p.
717-722
発行日: 2011年
公開日: 2011/10/08
[早期公開] 公開日: 2011/09/23
ジャーナル
フリー
The effect of the ethylenediaminetetraacetic acid (EDTA) treatment on the hybrid layer durability of total-etch dentin adhesives was investigated. A flat dentin surface was exposed and treated with 37% phosphoric acid or 0.1M EDTA. Dentin adhesive was applied and a 4 mm thick composite resin was built-up. Twenty 0.9×0.9 mm
2 resin-dentin beams were fabricated in each experimental group. Artificial aging with 10% NaClO was performed in half of the experimental groups for 1 hour. A micro-tensile bond strength (
μTBS) test was performed and the bonded interface was analyzed with transmission electron microscopy (TEM). The 37% phosphoric acid-treated group showed a lower
μTBS after artificial aging, whereas the 0.1M EDTA-treated group did not. TEM analysis revealed collagen fibrils dissolved in the 37% phosphoric acid-treated group but not in the 0.1M EDTA-treated group. Undissolved minerals were observed in the 0.1M EDTA-treated group. In conclusion, a dentin treatment with 0.1M EDTA is effective in improving the hybrid layer durability.
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Ayaka KISHI, Masayuki OTSUKI, Alireza SADR, Masaomi IKEDA, Junji TAGAM ...
2011 年 30 巻 5 号 p.
723-729
発行日: 2011年
公開日: 2011/10/08
[早期公開] 公開日: 2011/09/23
ジャーナル
フリー
This study evaluated the influence of different light sources on the efficiency of an office bleaching agent containing visible-light activating titanium dioxide photocatalyst (VL-TiO
2) using an artificial discoloration tooth model. Extracted bovine teeth were stained by black tea. The CIE
L*a*b* values were measured before and after nine consecutive treatments by the VL-TiO
2-containing bleaching agent (TiON in Office, GC, Tokyo, Japan). A halogen light unit (CB; CoBee, GC) or an LED unit (G-light, GC) with two modes (blue and violet: GL-BV, blue: GL-B) were used to activate the bleaching agent in three groups (
n=8). Brightness (
ΔL) and color difference (
ΔE) increased as bleaching repeated in all groups. Two-way ANOVA showed that both number of treatments and light sources significantly affected
ΔE (
p<0.05). GL-BV showed better bleaching effect than GL-B. In measurement of irradiation spectra, CB showed a wide spectrum (380–530 nm), GL-B had a sharp peak at 470 nm and GL-BV showed an additional peak at 405 nm. It was concluded that the light source influenced the efficiency of the tooth bleaching with VL-TiO
2.
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Naoshi TAKEUCHI, Miho MACHIGASHIRA, Daisuke YAMASHITA, Yoshinori SHIRA ...
2011 年 30 巻 5 号 p.
730-738
発行日: 2011年
公開日: 2011/10/08
[早期公開] 公開日: 2011/09/23
ジャーナル
フリー
A bi-layered silicon-releasable membrane consisting of a siloxane-poly(lactic acid) (PLA)-vaterite hybrid material (Si-PVH) microfiber mesh and a PLA microfiber mesh has been developed by an electrospinning method for guided bone regeneration (GBR) application. The bi-layered membrane was modified to a three-laminar structure by sandwiching an additional PLA microfiber mesh between the Si-PVH and PLA microfiber meshes (Si-PVH/PLA membrane). In this study, the influence of gamma irradiation, used for sterilization, on biological properties of the Si-PVH/PLA membrane was evaluated with osteoblasts and fibroblasts. After gamma irradiation, while the average molecular weight of the Si-PVH/PLA membrane decreased, the Si-PVH/PLA membrane promoted cell proliferation and differentiation (alkaline phosphatase activity and calcification) of osteoblasts, compared with the poly(lactide-co-glycolide) membrane. These results suggest that the gamma-irradiated Si-PVH/PLA membrane is biocompatible with both fibroblasts and osteoblasts, and may have an application for GBR.
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Gaute Floer JOHNSEN, Sébastien F. TAXT-LAMOLLE, Håvard J. ...
2011 年 30 巻 5 号 p.
739-748
発行日: 2011年
公開日: 2011/10/08
[早期公開] 公開日: 2011/09/23
ジャーナル
フリー
The aim of this study was to establish a wear model for testing composite filling materials with abrasion properties closer to a clinical situation. In addition, the model was used to evaluate the effect of filler volume and particle size on surface roughness and wear resistance. Each incisor tooth was prepared with nine identical standardized cavities with respect to depth, diameter, and angle. Generic composite of 3 different filler volumes and 3 different particle sizes held together with the same resin were randomly filled in respective cavities. A multidirectional wet-grinder with molar cusps as antagonist wore the surface of the incisors containing the composite fillings in a bath of human saliva at a constant temperature of 37°C. The present study suggests that the most wear resistant filling materials should consist of medium filling content (75%) and that particles size is not as critical as earlier reported.
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Alireza VALANEZAHAD, Kunio ISHIKAWA, Kanji TSURU, Michito MARUTA, Shig ...
2011 年 30 巻 5 号 p.
749-753
発行日: 2011年
公開日: 2011/10/08
[早期公開] 公開日: 2011/09/23
ジャーナル
フリー
To understand the feasibility of calcium (Ca) modification of type 316L stainless steel (316L SS) surface using hydrothermal treatment, 316L SS plates were treated hydrothermally in calcium chloride (CaCl
2) solution. X-ray photoelectron spectroscopic analysis revealed that the surface of 316L SS plate was modified with Ca after hydrothermal treatment at 200°C. And the immobilized Ca increased with CaCl
2 concentration. However no Ca-modification was occurred for 316L SS plates treated at 100°C. When Ca-modified 316L SS plate was immersed in simulated body fluid (SBF) with ion concentrations nearly equal to those of human blood plasma, low crystalline apatite was precipitated on its surface whereas no precipitate was observed on non Ca-modified 316L SS. The results obtained in the present study indicated that hydrothermal treatment at 200°C in CaCl
2 solution is useful for Ca-modification of 316L SS, and Ca-modification plays important role for apatite precipitation in SBF.
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Myat NYAN, Yusuke TSUTSUMI, Kei OYA, Hisashi DOI, Naoyuki NOMURA, Shoh ...
2011 年 30 巻 5 号 p.
754-761
発行日: 2011年
公開日: 2011/10/08
[早期公開] 公開日: 2011/09/23
ジャーナル
フリー
A novel coating technique of thin ceramic layer resembling teeth color on titanium (Ti) surface was developed by combination of sputter deposition of metal zirconium (Zr) and subsequent micro-arc oxidation (MAO) treatment. The oxide layer grown by MAO treatment had a porous structure with a thickness of approximately 6 micrometers and was mainly composed of zirconium dioxide (ZrO
2) with both tetragonal and monoclinic crystal structures. The surface of the specimen was hardened by this technique, and the hardness of the specimen was significantly larger than that of untreated Ti and MAO-treated Ti without Zr layer. The bonding strength test revealed that fracture occurred inside the oxide layer, indicating that adhesion between the oxide layer and the Ti substrate was sufficiently strong. From these results, this technique has an advantage for the development of novel dental materials with excellent mechanical and aesthetic properties.
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