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Sonia SANTANDER, Clara ALCAINE, Jaber LYAHYAI, Maria Angeles PÉREZ, C ...
2014 Volume 33 Issue 3 Pages
305-312
Published: May 30, 2014
Released on J-STAGE: May 31, 2014
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Interaction between cells and implant surface is crucial for clinical success. This interaction and the associated surface treatment are essential for achieving a fast osseointegration process. Several studies of different topographical or chemical surface modifications have been proposed previously in literature. The Biomimetic Advanced Surface (BAS) topography is a combination of a shot blasting and anodizing procedure. Macroroughness, microporosity of titanium oxide and Calcium/Phosphate ion deposition is obtained. Human mesenchymal stem cells (hMCSs) response
in vitro to this treatment has been evaluated. The results obtained show an improved adhesion capacity and a higher proliferation rate when hMSCs are cultured on treated surfaces. This biomimetic modification of the titanium surface induces the expression of osteblastic differentiation markers (RUNX2 and Osteopontin) in the absence of any externally provided differentiation factor. As a main conclusion, our biomimetic surface modification could lead to a substantial improvement in osteoinduction in titanium alloy implants.
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Ryan Jin Young KIM, Joo Hee SHIN
2014 Volume 33 Issue 3 Pages
313-318
Published: May 30, 2014
Released on J-STAGE: May 31, 2014
Advance online publication: February 06, 2014
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The objective of this study was to assess the cytotoxicity of EndoSeal, a novel mineral trioxide aggregate-based root canal sealer in comparison with two commonly used sealers, AH Plus and Sealapex. For cytotoxicity assay, MG-63 cells and human gingival fibroblasts were incubated in culture medium containing eluates of each sealer at 1, 3, and 7 days. Cell metabolism was evaluated by the WST-1 assay. For cell adhesion assay, disc specimens were fabricated from EndoSeal and AH Plus. MG-63 cells and human gingival fibroblasts were seeded on the discs, and after 1 day and 7 days of incubation, cell morphology and cell adhesion were examined by SEM. The order of cytotoxicity of root canal sealers was as follows: EndoSeal < AH Plus < Sealapex. Both types of cells seeded on the EndoSeal specimens were much larger, flat with rough margins compared to those on the AH Plus specimens. These results suggest that EndoSeal has a satisfactory cytocompatibility.
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Cemal YESILYURT, Kadir T. CEYHANLI, Cemile KEDİCİ ALP, Tahsin YILDIRIM ...
2014 Volume 33 Issue 3 Pages
319-324
Published: May 30, 2014
Released on J-STAGE: May 31, 2014
Advance online publication: March 08, 2014
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The purpose of this study was to compare
in vitro bonding effectiveness of Vertise Flow (VF), a new self-adhering flowable composite (FC), and Ultimate Flow (UF), a conventional FC, to BioAggregate (BA), and to investigate whether the use of self-etch or etch-andrinse adhesive improved the bond strength of VF to BA. Shear bond strengths of FC to BA were measured for this reason. Data were analyzed using Wilcoxon and Mann-Whitney
U-tests (
p=0.05). There were significant differences of bond strengths after 24- and 72-h (
p<0.05,
p<0.001). After 72-h, self-adhering FC may be used successfully with BA and no other adhesive, as an alternative to the combined use of conventional FC and self-etch adhesives. The use of etch-and-rinse adhesives with self-adhering FC may improve adhesion to BA.
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Shuai WANG, Lihong GUO, Chaminda Jayampath SENEVIRATNE, Bo HUANG, Jian ...
2014 Volume 33 Issue 3 Pages
325-331
Published: May 30, 2014
Released on J-STAGE: May 31, 2014
Advance online publication: March 04, 2014
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The microbial diversity of biofilms formed on the surfaces of amalgam, glass-ionomer cement, and resin composite was analyzed by denaturing gradient gel electrophoresis (DGGE). The V2-V3 region of salivary microbial 16S rDNA gene sequences of planktonic and biofilm bacteria, after 1 day and 1 week of incubation, was amplified by polymerase chain reaction (PCR) and analyzed by DGGE. The amounts of strongly adherent phylotypes after 1 day and 1 week on the three dental restorative materials were more than those on hydroxyapatite.
Streptococcus salivarius was detected in both loosely adherent and strong adherent groups of all 1-day samples. At 1 week, the amounts of loosely adherent and strongly adherent phylotypes present on the three restorative materials ranked in this ascending order: glass-ionomer cement < resin composite < amalgam. Results of DGGE analysis suggested that glass-ionomer cement was the best material of choice in terms of suppressing bacterial phylotypes in biofilms.
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Esra CAN SAY, Haktan YURDAGÜVEN, Batu Can YAMAN, Füsun ÖZER
2014 Volume 33 Issue 3 Pages
332-342
Published: May 30, 2014
Released on J-STAGE: May 31, 2014
Advance online publication: March 04, 2014
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The purpose of this study was to investigate surface roughness (Ra) and morphology of supra-nanofilled [Estelite Omega (EO), Estelite ∑ Quick (EQ)], micro-hybrid [Esthet.X HD (EHD), G-aenial (GAE)] and nano-hybrid [Clearfil Majesty Posterior (CMP), Charisma Diamond (CD), Beautifil II (BII)] composites polished with two-step polishing systems [Enhance/PoGo (EP); Venus Supra (VS)]. Composite discs, 30 of each type, were prepared. Each composite group was divided into three subgroups: Mylar (control), EP and VS. Ra was evaluated with profilometer. In each composite group, the control had the lowest Ra. With both polishing systems, EO and EQ had significantly the lowest Ra, whereas CMP and BII had the highest. Except for GAE, CD and BII, the differences in Ra between EP and VS in each composite group were significant, showing smoother surfaces for EP. Supra-nanofilled composites created smoother surfaces than nano-hybrids, and their performance was similar or slightly better than that of micro-hybrids.
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Seda CENGIZ, Sinasi SARAC, Mutlu ÖZCAN
2014 Volume 33 Issue 3 Pages
343-348
Published: May 30, 2014
Released on J-STAGE: May 31, 2014
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Medical problems such as gastroesophageal reflux disease can cause considerable damage to restorations in the oral environment. This study evaluated the effects of gastric juice on the surface characteristics of different types of laboratory-processed indirect composites with different filler particles and polymerization modes. Specimens were prepared from Tescera (TES; Bisco), Sinfony (SIN; 3M ESPE), Solidex (SOL; Shofu), and Adoro (AD; Ivoclar Vivadent). Before exposing the specimens to simulated gastric juice for 24 h, color, surface roughness, and microhardness were measured on one half of the polished flat surface of each specimen. After exposure to the simulated gastric juice, the same tests were repeated on the other half of specimen surface. Results indicated that gastric juice had a significant impact on color change (
p<0.001). AD showed the largest surface roughness change among the resins (
p<0.001). Gastric juice also significantly affected the microhardness of the materials, and AD and TES showed statistically similar change in microhardness (
p>0.05).
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Weiqiang YU, Kewu GUO, Baowei ZHANG, Weimin WENG
2014 Volume 33 Issue 3 Pages
349-354
Published: May 30, 2014
Released on J-STAGE: May 31, 2014
Advance online publication: April 17, 2014
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The purpose of the present study is to evaluate the fracture resistance of endodontically treated maxillary premolars restored using CAD/CAM onlays or crowns and luted with two types of resin cement. Forty all-ceramic crowns and twenty onlays were fabricated on maxillary premolars using the Cerec 3 system (
n=10). The abutments were randomly subjected to two different procedures: Endodontic treatment was performed on forty teeth restored through a mesio-occlusal-distal (MOD) cavity preparation with composite resin fillings; twenty teeth without endodontic treatment served as control. In endodontically treated teeth restored using IPS e.max CAD crowns or onlays, the fracture loads were lower than those of the control. Endodontic treatment of teeth restored using CAD/CAM crowns does not impair the fracture load but shows more severe fractures than teeth restored using CAD/CAM onlays. This suggests that a CAD/CAM onlay might be an effective method for the restoration of endodontically treated premolars with MOD cavity defect.
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Rie FUJITA, Wataru KOMADA, Kosuke NOZAKI, Hiroyuki MIURA
2014 Volume 33 Issue 3 Pages
355-362
Published: May 30, 2014
Released on J-STAGE: May 31, 2014
Advance online publication: April 29, 2014
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This study aimed to investigate the maximum depth imaging and optical properties of the dentin near the pulp by using optical coherence tomography (OCT) and to explore the possibility of measuring the remaining dentin thickness (RDT). Human third molars were used. In experiment 1, the cuspal dentin blocks (0.50-mm to 1.75-mm thickness) were prepared. Each specimen was scanned using OCT. OCT images could be obtained for all specimens with 1.00-mm or less thicknesses. In experiment 2, dentin-pulp complex slices (0.50-mm and 1.00-mm RDT) were prepared. Each specimen was scanned using OCT and micro-computed tomography, and compared. The resulting length change rates of OCT images for the 0.50-mm RDTs were significantly lower than those of the 1.00-mm RDTs. Within the limitations of this study, OCT was effective for measuring the 1.00-mm or less RDT and preventing pulpal injury, while considering the length change rate of OCT image as a variable.
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Shingo KURODA, Hiroto WATANABE, Akira NAKAJIMA, Noriyoshi SHIMIZU, Eij ...
2014 Volume 33 Issue 3 Pages
363-367
Published: May 30, 2014
Released on J-STAGE: May 31, 2014
Advance online publication: April 29, 2014
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The objective of the study was to measure the torque moment delivered by a novel elastic bendable wire, Ti-Nb wire, and to compare it with nickel-titanium (Ni-Ti) and titanium-molybdenum (Ti-Mo) alloy wires. Two sizes of Ti-Nb, Ni-Ti and Ti-Mo alloy wires and 0.022-inch slot stainless steel brackets were ligated with elastic modules or ligature wires. The torque moment delivered by the various wire-bracket combinations was measured using a torque gauge at the temperature and humidity of 37°C and 50%, respectively. As the degree of applied torque and the inserted wire size increased, the torque moment gradually increased. The torque moment of Ti-Nb wires was smaller than those of Ni-Ti wires and Ti-Mo wires, at more than 20 degrees applied torque. The torque moment with wire ligation was significantly larger than those with elastic ligation.
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Sertan ERGUN, Duygu OFLUOĞLU, Alp SARUHANOĞLU, Burçin KARATAŞLI, Ediz ...
2014 Volume 33 Issue 3 Pages
368-372
Published: May 30, 2014
Released on J-STAGE: May 31, 2014
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Miniplates have been used during the last decade to facilitate stability between bony fragments in the maxillofacial region and are currently the preferred surgical method for the fixation of fractures and osteotomies. The aim of this study was to evaluate and compare the biomechanical behaviors of six different types of miniplates used to reconstruct mandibular body fractures: Group 1 (straight, 2 holes, 12.0 mm spacing), Group 2 (straight, 4 holes, 9.0 spacing), Group 3 (straight, 6 holes, 9.0 mm spacing), Group 4 (L-shaped, 4 holes, 9.0 mm spacing, right hand plate), Group 5 (Y-shaped, 5 holes, 12.0 mm spacing), and Group 6 (double Y-shaped, 6 holes, 9.0 mm spacing). Thirty bovine hemimandibles and a custom-made 3-point biomechanical test frame mounted on a Shimadzu universal test machine were used to evaluate the six different miniplate systems. Results revealed that Group 1 (straight, 2 holes, 12.0 mm spacing) and Group 4 (9.0 mm spacing, right hand plate) had the lowest biomechanical stability, whereas Group 6 (6 holes, 9.0 mm spacing) had the highest biomechanical stability. Group 6 also provided statistically greater resistance to displacement than Group 1 and Group 4.
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Tasuku INAGAKI, Wataru KOMADA, Reina NEMOTO, Keiichi YOSHIDA, Hiroyuki ...
2014 Volume 33 Issue 3 Pages
373-382
Published: May 30, 2014
Released on J-STAGE: May 31, 2014
Advance online publication: April 29, 2014
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The purpose of this study was to evaluate the surface strain of zirconia fixed partial denture frameworks and their abutment roots when restored with two types of post and core materials. Artificial mandibular first premolars and second molars were used as the abutment teeth. Posts and cores were of two types: resin composite with glass fiber posts (RC) and cast platinum gold alloy (MC). The cores and 4-unit zirconia frameworks were bonded to the specimens. Static loading was applied to the occlusal surfaces, and the surface strain of the frameworks and roots (distal premolar and mesial molar) was measured by strain gauge method. Premolar root showed a significantly higher magnitude of principal strain than molar root. RC showed a significantly higher magnitude of principal strain than MC. The results suggest that MC restrain the surface strain compared to RC when the missing teeth are replaced by a 4-unit zirconia framework.
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Hideaki HASE, Akikazu SHINYA, Daiichiro YOKOYAMA, Akiyoshi SHINYA, Yut ...
2014 Volume 33 Issue 3 Pages
383-388
Published: May 30, 2014
Released on J-STAGE: May 31, 2014
Advance online publication: April 29, 2014
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The purpose of this study was to evaluate the stress distribution on the alveolar bone surrounding abutment teeth and the displacement of the Aramany Class IV obturator prosthesis with two different clasp designs. Three-dimensional finite element models of an Aramany Class IV maxillary defect were constructed. Two different clasp designs on an obturator prosthesis (double Akers clasps and multiple Roach clasps) and two different load conditions (vertical and horizontal) were compared. Finite element analysis was used to calculate the equivalent stress. The difference in the clasp design of the Aramany Class IV obturator prosthesis affected the stress distribution of the alveolar bone surrounding the abutment teeth and the displacement of the obturator prosthesis. Multiple Roach clasps reduced the stress distribution on the alveolar bone surrounding the abutment teeth and the displacement of the Aramany Class IV obturator prosthesis compared to double Akers clasps.
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Kazuko NAKAJO, Masatoshi TAKAHASHI, Masafumi KIKUCHI, Yukyo TAKADA, Os ...
2014 Volume 33 Issue 3 Pages
389-393
Published: May 30, 2014
Released on J-STAGE: May 31, 2014
Advance online publication: April 29, 2014
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Titanium-silver (Ti-Ag) alloy has been improved for machinability and mechanical properties, but its anti-biofilm properties have not been elucidated yet. Thus, this study aimed to evaluate the effects of Ti-Ag alloy on biofilm formation and bacterial viability in comparison with pure Ti, pure Ag and silver-palladium (Ag-Pd) alloy. Biofilm formation on the metal plates was evaluated by growing
Streptococcus mutans and
Streptococcus sobrinus in the presence of metal plates. Bactericidal activity was evaluated using a film contact method. There were no significant differences in biofilm formation between pure Ti, pure Ag and Ag-Pd alloy, while biofilm amounts on Ti-20% Ag and Ti-25% Ag alloys were significantly lower (
p<0.05). In addition, Ti-Ag alloys and pure Ti were not bactericidal, although pure Ag and Ag-Pd alloy killed bacteria. These results suggest that Ti-20% Ag and Ti-25% Ag alloys are suitable for dental material that suppresses biofilm formation without disturbing healthy oral microflora.
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Haruyoshi TAKAHASHI
2014 Volume 33 Issue 3 Pages
394-401
Published: May 30, 2014
Released on J-STAGE: May 31, 2014
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Five experimental 10-methacryloyloxydecyl dihydrogen phosphate (MDP)-based one-step self-etch adhesives were designed by varying amounts of MDP. The aim of this study was to examine the effect of the quantity of calcium salt of MDP (MDP-Ca) salt produced by demineralization on the bond durability between experimental one-step adhesives and enamel or dentin. Bond strengths of experimental adhesives to the enamel and dentin were measured, before and after 30,000×thermocycling. The fractured enamel and dentin samples as well as the fractured adhesive surfaces obtained during adhesion test were analyzed by a scanning electron microscope and energy-dispersive X-ray microscope. An increase in the amount of MDP-Ca salt to above 37.2 mg/g drastically decreased the dentin bond strength and changed the fracture type during the thermocycling process. In contrast, the enamel bond strength remained unchanged, although the fracture type changed to an interfacial failure with increasing the amount of MDP-Ca salt to 78.3 mg/g.
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Yu URUSHIBARA, Tomoko OHSHIMA, Maki SATO, Yoshiko HAYASHI, Tohru HAYAK ...
2014 Volume 33 Issue 3 Pages
402-414
Published: May 30, 2014
Released on J-STAGE: May 31, 2014
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The purpose of this study was to perform a quantitative and qualitative evaluation of the biofilms formed on framework alloys
in vitro. The biofilms formed by unfiltered fresh human saliva or
Streptococcus mutans and/or
Candida albicans on commercially pure titanium and gold-copper-platinum demonstrated higher amounts than other alloy and resin samples. In contrast, the silverpalladium-copper-gold showed a significantly decreased level of biofilm formation. Although the adhesion level of
Streptococcus mutans on cobalt-chromium was high, that of
Candida albicans was less extensive. A T-RFLP analysis and qualitative PCR of the microbes in the biofilms were performed. In a cluster analysis of all T-RFLP profiles, the cobalt-chromium pattern was integrated into one cluster. On qualitative PCR, the existence of microorganisms related to caries, preriodontitis and aspiration pneumonia was observed. Our results showed that the biofilm formation on each framework alloy was different in terms of both the quantity and quality.
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Yuki HASEGAWA, Shin-ichi GOTO, Hideo OGURA
2014 Volume 33 Issue 3 Pages
415-421
Published: May 30, 2014
Released on J-STAGE: May 31, 2014
Advance online publication: April 29, 2014
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This study aimed to evaluate the effect of EDTA solutions (3% and 10% EDTA•2Na) on corrosion fatigue of three Ni-Ti files with different shapes, in comparison with other solutions (6% NaClO, 3% H
2O
2, 0.9% NaCl and distilled water). Ni-Ti files were subjected to rotational bending in a bent glass tube (30° and 60° angles) filled with the solutions, and the number of rotations to failure was counted. At 30° bent angle, files in the two EDTA solutions showed significantly lower resistance than those in distilled water, but no significant difference was found between the two EDTA solutions. Fatigue resistance of two tested files in the two EDTA solutions was not significantly different from those in the other three solutions, whereas one file in EDTA solutions showed significantly lower resistance than that in 3% H
2O
2. At 60° bent angle, early failure within 1–2.5 min was observed for all tested files, and no significant difference was found among the six solutions. At both angles, significant differences in fatigue resistance were observed among the three tested files, which could be related to the difference in the cross-sectional shapes of the files.
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Miku KAZAMA-KOIDE, Kazuo OHKUMA, Hideo OGURA, Yukio MIYAGAWA
2014 Volume 33 Issue 3 Pages
422-429
Published: May 30, 2014
Released on J-STAGE: May 31, 2014
Advance online publication: April 29, 2014
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The purpose of this work was to fabricate zirconia copings from fully sintered Y-TZP blocks using a Nd:YVO
4 nanosecond laser in order to avoid complicated procedures using conventional CAD/CAM systems. To determine the most appropriate power level of a Nd:YVO
4 laser, cuboid fully sintered Y-TZP specimens were irradiated at six different average power levels. One-way ANOVAs for the average surface roughness and laser machining depth revealed that an average power level of 7.5 W generated a smooth machined surface with high machining efficiency. Y-TZP copings were then machined using the proposed method with the most appropriate power level. As the number of machining iterations increased, the convergence angles decreased significantly (
p<0.01). The accuracy of the machined copings was judged to be good based on 3D measurements and traditional metal die methods. The proposed method using the nanosecond laser was demonstrated to be useful for fabricating copings from fully sintered Y-TZP.
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Masahiro IIJIMA, Shuichi ITO, Susumu NAKAGAKI, Naohisa KOHDA, Takeshi ...
2014 Volume 33 Issue 3 Pages
430-436
Published: May 30, 2014
Released on J-STAGE: May 31, 2014
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This study investigated the like-remineralizing ability of experimental toothpaste containing surface reaction-type pre-reacted glassionomer (S-PRG) filler on etched enamel. Human enamel blocks were etched with 35% phosphoric acid and immersed in 5-mL distilled water, fourfold diluted solution of NaF-containing toothpaste, or S-PRG filler-containing experimental toothpaste. Nanoindentation testing was carried out during immersion and the enamel surfaces were observed by scanning electron microscopy. Elemental analysis of the ions in each solution was performed using inductively coupled plasma atomic emission spectroscopy and fluoride electrode. After 1 month of immersion, the hardness and elastic modulus of the specimen immersed in S-PRG filler-containing toothpaste showed significantly greater values than those of the specimen immersed in NaF-containing toothpaste. Considerable amounts of Al, B, Na, Si, Sr, F ions were detected in the solution of S-PRG filler-containing toothpaste. Experimental S-PRG filler-containing toothpaste may enhance the like-remineralizing ability of etched enamel surfaces due to its ion-releasing ability.
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