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Laura Molinar FRANCO, Lucas Silveira MACHADO, Fabio Martins SALOMÃO, P ...
2016 Volume 35 Issue 1 Pages
13-20
Published: January 29, 2016
Released on J-STAGE: January 31, 2016
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This study evaluated the effects of combining enamel microabrasion and dental bleaching on the physical properties of enamel, using
in vitro and
in situ conditions and evaluating surface roughness, enamel microhardness and scanning electron microscopy images. One hundred sound bovine teeth were sectioned and cut into discs and randomly divided into 10 study groups (
n=10). The results were submitted to Analysis of Variance (ANOVA) for repeated measures, followed by the Tukey test, with significance at 5%. Enamel surface roughness was significantly influenced by microabrasion, regardless of being combined with dental bleaching, for both HS (Human Saliva) or AS (Artificial Saliva) condition. Enamel microhardness was significantly decreased in the groups in which enamel microabrasion was performed, regardless its combination with dental bleaching; although storage in HS reestablished the initial enamel microhardness. It was concluded that dental bleaching does not cause major damage to microabraided enamel, and that only human saliva recovered the initial enamel microhardness.
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Mami HIGASHI, Mariko MATSUMOTO, Asuka KAWAGUCHI, Jiro MIURA, Takuya MI ...
2016 Volume 35 Issue 1 Pages
21-28
Published: January 29, 2016
Released on J-STAGE: January 31, 2016
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The present study assessed the effect of sandblasting and silanization on resin cement bond strengths to CAD/CAM resin blocks. Twenty four blocks (KATANA AVENCIA BLOCK) were divided into two resin cement groups (PANAVIA V5 [PV5] and PANAVIA SA CEMENT HANDMIX [PSA]), and further divided into four subgroups representing different surface treatment methods: no treatment (Ctl), silanization (Si), sandblasting (Sb), and Sb+Si. After resin application, microtensile bond strengths (μTBSs) were measured immediately, 1, 3 and 6 months after water storage. In addition, surfaces resulting from each of the treatment methods were analyzed by scanning electron microscopy (SEM). Three-way analysis of variance revealed a statistically significant effect for the parameters ‘surface treatment’ (
p<0.001,
F=370), ‘resin cement’ (
p<0.001,
F=103, PSA<PV5), and ‘water aging’ (
p<0.001,
F=18). Control treatment yielded significantly lower μTBS values compared to other treatment subgroups (
p<0.001). The highest bond strength was achieved with Sb+Si treatment. SEM revealed that sandblasting roughened surfaces.
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Asuka KAWAGUCHI, Mariko MATSUMOTO, Mami HIGASHI, Jiro MIURA, Takuya MI ...
2016 Volume 35 Issue 1 Pages
29-36
Published: January 29, 2016
Released on J-STAGE: January 31, 2016
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The present study assessed the effect of ultrasonic and acid cleaning on resin cement bonding to CAD/CAM resin blocks. One of two resin cements, PANAVIA V5 (PV5) or PANAVIA SA CEMENT HANDMIX (PSA), were bonded to one of 24 CAD/CAM blocks (KATANA AVENCIA BLOCK). Each cement group was divided into four subgroups: no cleaning (Ctl), ultrasonic cleaning (Uc), acid cleaning (Ac) and Uc+Ac. Micro-tensile bond strengths (µTBSs) were measured immediately and 1, 3, and 6 months after water storage. Block surfaces after each treatment were analyzed by scanning electron microscopy. Analysis of variance revealed a statistically significant effect for the parameters ‘surface treatment’ (
p<0.001,
F=40), ‘resin cement’ (
p<0.001,
F=696) and ‘water aging’ (
p<0.001,
F=71). The PV5 group exhibited higher µTBS values than the PSA group. Although cleaning after sandblasting was effective in removing residual alumina particles, it did not affect the long-term bonding durability with non-contaminated CAD/CAM resin blocks.
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Koichi SHINKAI, Yoshihisa TAIRA, Shiro SUZUKI, Masaya SUZUKI
2016 Volume 35 Issue 1 Pages
37-44
Published: January 29, 2016
Released on J-STAGE: January 31, 2016
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The purpose of this study was to examine three- and two-body wear values of flowable resin composites for posterior restorations, using a mechanical loading device. The cavities prepared on flattened extracted molars were restored with flowable resin composites (Clearfil Majesty LV: MLV, Estelite Flow Quick: EFQ, Beautifil Flow Plus F00: BFP, and MI Fill: MIF) using accompanying adhesive systems. A universal resin composite (Clearfil Majesty) was used as a control. The specimens were subjected to
in vitro three- and two-body wear testing. MLV showed high wear value (three-body: 14.69 µm, two-body: 0.268 mm
3) compared with other materials tested in both three- and two-body wear tests. BFP showed high three-body wear value (5.78 µm), whereas low two-body wear value (0.008 mm
3). MIF and EFQ showed equivalent wear values (MIF, three-body: 0.42 µm, two-body: 0.026 mm
3; EFQ, three-body: 1.15 µm, two-body: 0.14 mm
3) to that of the control in both wear tests.
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Yukiko IWASAKI, Hisako HIRAGUCHI, Eriko IWASAKI, Takayuki YONEYAMA
2016 Volume 35 Issue 1 Pages
45-50
Published: January 29, 2016
Released on J-STAGE: January 31, 2016
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This study investigated the effects of disinfection of agar-alginate combined impressions on the surface properties of the resulting stone casts. Two brands of cartridge-form agar impression material and one alginate impression material were used. Agar-alginate combined impressions of smooth glass plates were prepared. The impressions were immersed in 0.55% ortho-phthalaldehyde solution or 0.5% sodium hypochlorite solution for 1, 3, 5 and 10 min. A stone cast made with an impression that had not been immersed was prepared as a control. The surface roughness (Ra) of the stone casts was measured, and the cast surfaces were observed by SEM. Immersion of agar-alginate combined impressions in 0.5% sodium hypochlorite solution for up to 10 min had no serious adverse effects on the surface properties of the stone casts. In contrast, even 1 min of immersion in 0.55% ortho-phthalaldehyde solution caused deterioration of the cast surface properties.
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Taichen LIN, Rie KAWAMURA, Akira AOKI, Shizuko ICHINOSE, Koji MIZUTANI ...
2016 Volume 35 Issue 1 Pages
51-62
Published: January 29, 2016
Released on J-STAGE: January 31, 2016
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Though the Er:YAG laser (ErL) has been used in periodontal therapy, the irradiated tip damage has not been studied in detail. In this study, the change in the energy output, surface morphology, and temperature of quartz tips was evaluated following contact irradiation. Soft tissue, calculus on extracted human teeth, and porcine bone were irradiated by ErL for 60 min at 14.2 or 28.3 J/cm
2/pulse and 20 Hz with or without water spray. The energy output ratio declined the most in the calculus group, followed by the bone and soft tissue groups with and/or without water spray. Carbon contamination was detected in all groups, and contamination by P, Ca, and/or other inorganic elements was observed in the calculus and bone groups. The rate of energy output reduction and the degree of surface alteration/contamination is variously influenced by the targeting tissue, temperature elevation of the tip and water spray.
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Christopher IGIEL, Michael WEYHRAUCH, Stefan WENTASCHEK, Herbert SCHEL ...
2016 Volume 35 Issue 1 Pages
63-69
Published: January 29, 2016
Released on J-STAGE: January 31, 2016
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The aim of this study was to compare the agreement rate (%) and color difference (Δ
E*
ab) of three dental color-measuring devices, with the visual shade identification. The tooth color were determined by two operators, which were advised to select a VITA classic shade tab in each other’s agreement. The Shadepilot (SP), CrystalEye (CE) and ShadeVision (SV) were used to measure tooth color. Statistically analyses include agreement rate (%), color difference (Δ
E*
ab), McNemar test (
p=0.05), Student’s
t-test (
p=0.05) and Bland Altman scatterplots. The SP had an agreement of 56.3% with the visual shade determination, the CE 49.0% and SV 51.3%. Δ
E*
ab of the visually and instrumentally selected shade tabs and natural teeth were frequently above the threshold for acceptability. Comparing both methods, for SP Δ
E*
ab values differ in a range of clinical acceptability.
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Toru SHIIYA, Kiyoshi TOMIYAMA, Junko IIZUKA, Haruhiko HASEGAWA, Erika ...
2016 Volume 35 Issue 1 Pages
70-75
Published: January 29, 2016
Released on J-STAGE: January 31, 2016
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This study investigated the
in vitro anti-demineralization effects of resin-based temporary filling materials containing surface prereacted glass-ionomer (S-PRG) filler on dentin. Bovine root dentin specimens with a 3×3 mm experimental surface were divided into four treatment groups: DuraSeal (DU) as a control, S-PRG filler-free temporary material (S0), material containing 10% (S10) and 20% (S20) S-PRG filler. Each material was applied to 3×2 mm of the experimental surface, and the specimens were immersed in 8% methylcellulose gel demineralization system for one week at 37˚C. Mineral profiles and integrated mineral loss (IML) of lesions induced on the surface (3×1 mm) adjacent to the materials were computed by transversal microradiography. S10 and S20 yielded thick surface layers and shallow lesion bodies, with significantly lower IML than DU and S0 (
p<0.05, Tukey’s test). These findings indicate that temporary filling resin-based materials containing over 10% of S-PRG filler content have anti-demineralization effects on adjacent dentin.
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Potchaman SINAVARAT, Chuchai ANUNMANA, Thitima MUANJIT
2016 Volume 35 Issue 1 Pages
76-81
Published: January 29, 2016
Released on J-STAGE: January 31, 2016
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This study compared the fracture toughness values (K
IC), which were derived from simplified techniques: the indentation fracture (IF), the indentation strength (IS), and fractographic approach to that from a standard testing using surface cracks in flexure (SCF). Forty bar specimens, twenty IPS Empress
® Esthetic and twenty IPS e.max
®Ceram were prepared. Ten specimens in each material were tested by IF technique, IS technique and fractographic approach, and additional 10 specimens were tested by the SCF technique. This study showed that the mean K
IC derived from fractographic approach were not significantly different from that of the SCF in both materials (p>0.05) whereas the mean K
IC from indentation techniques rarely agreed with those of the standard technique. The K
IC determination is sensitive to the methods used that affect accuracy. Consequently, test selection should be based on a sound understanding and inherent limitations of each technique.
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Isil BUYUKHATIPOGLU, A. Semih OZSEVIK, Asli SECILMIS, Aslihan USUMEZ
2016 Volume 35 Issue 1 Pages
82-88
Published: January 29, 2016
Released on J-STAGE: January 31, 2016
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The aim of this study was to compare the effect of Er:YAG laser irradiation and adhesive systems on the microtensile bond strength (μTBS) of flowable resin to dentin. The flat dentin surfaces of 30 wisdom molar teeth were randomly divided into 3 groups (
n=10): no laser etching (control), laser etching using QSP and MSP modes. After the application of the flowable and the composite resin, and 5,000 thermal aging, the μTBS results were analyzed with two-way analysis of variance and Tukey’s honest standard of difference (HSD) tests. There were no significant differences between the μTBS of the self-etch group and the total-etch groups for MSP (
p>0.05). MSP mode is a useful pulse mode for dentin surface treatment due to elimination of the acid-etching step.
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Takako YOSHIKAWA, Makoto MORIGAMI, Alireza SADR, Junji TAGAMI
2016 Volume 35 Issue 1 Pages
89-96
Published: January 29, 2016
Released on J-STAGE: January 31, 2016
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The aim of this study was the effects of different light curing methods on marginal sealing and resin composite adaptation to the cavity wall using the dye penetration test and environmental scanning electron microscope (SEM) observations. Cylindrical cavities were prepared on cervical regions. The teeth were restored with Clearfil Liner Bond 2 V adhesive and filled with Clearfil Photo Bright or Palfique Estelite resin composites. These resins were cured with a conventional light-curing method or a slow-start curing method. After thermal cycling, the specimens were subjected to the dye penetration test to evaluate marginal sealing and adaptation of the resin composites to the cavity walls. These resin-tooth interfaces were then observed using environmental SEM. The light-cured resin composite, which exhibited increased contrast ratios during polymerization, suggests high compensation for polymerization stress using the slow-start curing method. There was a high correlation between dye penetration test and environmental SEM observation.
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Kun QIAN, Hong PAN, Yinglong LI, Guomin WANG, Jue ZHANG, Jie PAN
2016 Volume 35 Issue 1 Pages
97-103
Published: January 29, 2016
Released on J-STAGE: January 31, 2016
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The changes of denture base acrylic resin surface properties under cold plasma and the relationships with time were investigated. Cold plasma treated the specimens for 30 s, 60 s, 90 s, and 120 s, respectively. Water contact angles were measured immediately after the treatment, 48 h, 15 days and 30 days later. Surface roughness was measured with 3-D laser scanning microscope.
Candida albicans adherence was evaluated by CFU counting. Chemical composition was monitored by X-ray photoelectron spectroscopy analysis. Water contact angle reduced after treated for 30 s. No changes were observed with time prolonged, except the durability. There were no differences in roughness among all groups. However, treatment groups showed significantly lower
C. albicans adherence. XPS demonstrated a decrease in C/O, and this reduction was affected by treatment time. Cold plasma was an effective means of increasing hydrophilicity of acrylic resin and reducing
C. albicans adherence without affecting physical properties.
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Fangfang XIE, Xiaolang WEI, Qiurong LI, Tong ZHOU
2016 Volume 35 Issue 1 Pages
104-111
Published: January 29, 2016
Released on J-STAGE: January 31, 2016
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This study evaluated the biomineralization and dentinal tubules occlusion abilities of the carboxyl-terminated polyamidoamine dendrimer (PAMAM-COOH) on human demineralized dentin
in vivo at different time points. Demineralization dentin model with and without treated with PAMAM-COOH were sutured to the interior side of the rat’s cheeks, that was incubated in the rats’ saliva for 2, 4 and 6 weeks respectively. Finally, the newly formed precipitates were characterized by SEM, EDS, XRD and microhardness test. The hydroxyapatite (HA) on the dentin treated with PAMAM-COOH were formed gradually with the time going by, and the regenerated HA has a similar crystal structure with natural dentin, whereas the crystallites did not exist on the control group. The microhardness of PAMAM-COOH-applied specimens had a significantly higher than those without application. These results suggest that the PAMAM-COOH promoted the biomineralization of demineralized dentin and displayed favourable effects on blocking the open dentinal tubules.
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Shahbaz KHAN, Muhammad KALEEM, Muhammad Amber FAREED, Amir HABIB, Kefi ...
2016 Volume 35 Issue 1 Pages
112-117
Published: January 29, 2016
Released on J-STAGE: January 31, 2016
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The purpose of this study was to investigate the chemical composition and particle morphology of white mineral trioxide aggregate (WMTA) and two white Portland cements (CEM 1 and CEM 2). Compositional analysis was performed by energy dispersive X-ray spectroscopy, X-ray fluorescence spectrometry and X-ray diffraction whereas, morphological characteristics were analyzed by scanning electron microscope and Laser scattering particle size distribution analyzer. The elemental composition of WMTA, CEM 1 and CEM 2 were similar except for the presence of higher amounts of bismuth in WMTA. Calcium oxide and silicon oxide constitute the major portion of the three materials whereas, tricalcium silicate was detected as the major mineral phase. The particle size distribution and morphology of WMTA was finer compared to CEM 1 and CEM 2. The three tested materials had relatively similar chemical composition and irregular particle morphologies.
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Masako TSUKANAKA, Shunsuke FUJIBAYASHI, Mitsuru TAKEMOTO, Tomiharu MAT ...
2016 Volume 35 Issue 1 Pages
118-125
Published: January 29, 2016
Released on J-STAGE: January 31, 2016
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Selective laser melting (SLM) technology is useful for the fabrication of porous titanium implants with complex shapes and structures. The materials fabricated by SLM characteristically have a very rough surface (average surface roughness,
Ra=24.58 µm). In this study, we evaluated morphologically and biochemically the specific effects of this very rough surface and the additional effects of a bioactive treatment on osteoblast proliferation and differentiation. Flat-rolled titanium materials (
Ra=1.02 µm) were used as the controls. On the treated materials fabricated by SLM, we observed enhanced osteoblast differentiation compared with the flat-rolled materials and the untreated materials fabricated by SLM. No significant differences were observed between the flat-rolled materials and the untreated materials fabricated by SLM in their effects on osteoblast differentiation. We concluded that the very rough surface fabricated by SLM had to undergo a bioactive treatment to obtain a positive effect on osteoblast differentiation.
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Makbule Bilge AKBULUT, Melek AKMAN, Arslan TERLEMEZ, Guldane MAGAT, Se ...
2016 Volume 35 Issue 1 Pages
126-131
Published: January 29, 2016
Released on J-STAGE: January 31, 2016
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The aim of this study was to evaluate the efficacy of Twisted File (TF) Adaptive, Reciproc, and ProTaper Universal Retreatment (UR) System instruments for removing root-canal-filling. Sixty single rooted teeth were decoronated, instrumented and obturated. Preoperative CBCT scans were taken and the teeth were retreated with TF Adaptive, Reciproc, ProTaper UR, or hand files (
n=15). Then, the teeth were rescanned, and the percentage volume of the residual root-canal-filling material was established. The total time for retreatment was recorded, and the data was statistically analyzed. The statistical ranking of the residual filling material volume was as follows: hand file=TF Adaptive>ProTaper UR=Reciproc. The ProTaper UR and Reciproc systems required shorter periods of time for retreatment. Root canal filling was more efficiently removed by using Reciproc and ProTaper UR instruments than TF Adaptive instruments and hand files. The TF Adaptive system was advantageous over hand files with regard to operating time.
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Su-Young LEE, Chang-Bin CHO, Jai-Young KOAK, Sung-Eun YANG
2016 Volume 35 Issue 1 Pages
132-137
Published: January 29, 2016
Released on J-STAGE: January 31, 2016
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This study evaluated how zirconia thickness affects shear bond strength (SBS) between zirconia and dual-cure resin cement. Eighty specimens (40 blocks of 1 mm thickness zirconia and 20 of each 1.5 and 2 mm) were divided into 8 groups according to zirconia thickness and light-curing time. Group A, B, C, and D were light-polymerized during 20 s and group E, F, G, and H were light-cured during 40 s. Self-adhesive dual-cure resin cement was placed onto the zirconia surfaces and then light-polymerized. The mean SBS of the 40 s curing time group was statistically higher than that of the 20 s curing time group. However, curing time did not affect the SBS significantly in the 2 mm thickness groups. The mean SBS of the 1.5 and 2 mm groups were statistically lower than those 1 mm groups. Therefore, zirconia thickness significantly affected the SBS of self-adhesive dual-cure resin cement.
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Su-Hyeon KIM, Tack-Oon OH, Ju-Young KIM, Chun-Woong PARK, Seung-Ho BAE ...
2016 Volume 35 Issue 1 Pages
138-146
Published: January 29, 2016
Released on J-STAGE: January 31, 2016
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The aim of this study was to observe the effects of different test conditions on the flexural properties of root canal post. Metal- and fiber-reinforced composite root canal posts of various diameters were measured to determine flexural properties using a threepoint bending test at different conditions. In this study, the span length/post diameter ratio of root canal posts varied from 3.0 to 10.0. Multiple regression models for maximum load as a dependent variable were statistically significant. The models for flexural properties as dependent variables were statistically significant, but linear regression models could not be fitted to data sets. At a low span length/post diameter ratio, the flexural properties were distorted by occurrence of shear stress in short samples. It was impossible to obtain high span length/post diameter ratio with root canal posts. The addition of parameters or coefficients is necessary to appropriately represent the flexural properties of root canal posts.
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Han-Sol CHA, Dong-Hoon SHIN
2016 Volume 35 Issue 1 Pages
147-152
Published: January 29, 2016
Released on J-STAGE: January 31, 2016
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We evaluated the antibacterial properties of three disinfectants [2% chlorhexidine (CHX), 6% sodium hypochlorite (NaOCl), and 0.01% urushiol)] against
Streptococcus mutans and their effects on bond strength of Scotchbond
TM Universal. The reduction in bacterial growth was evaluated by the colony counting method. Total 105 specimens were assigned to seven groups, according to surface pretreatment: control group (C) without pretreatment; chlorhexidine gluconate with rinse (CR) or without rinse (CD); NaOCl with rinse (NR) or without rinse (ND); and urushiol with rinse (UR) or without rinse (UD). The shear bond test was performed at a cross-head speed of 0.5 mm/min. None of the disinfected specimens had viable microbes after a 30 min incubation. The control group exhibited the strongest bond; however, no significant difference was detected with the disinfectant-treated groups, except weak bonding with ND group. These findings suggest that all disinfectants tested had strong antibacterial capacity and may better be rinsed away.
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