-
Masafumi KIKUCHI
2010 Volume 29 Issue 6 Pages
637-641
Published: 2010
Released on J-STAGE: November 26, 2010
Advance online publication: November 19, 2010
JOURNAL
FREE ACCESS
The purpose of the present study was to establish a geometric design method for class I inlay cavities as a future method of computer-aided tooth preparation. Major occlusal fissures were used as a starting point of the cavity design and marked as multiple continuous line segments. An experimental cavity outline was defined by circular arcs and Bézier curves with three design parameters: minimum radius of curvature of the convex portion, taper angle of the convex portion of a cavity, and dovetail convexity angle. The experimental software was used to design class I inlay cavities for mandibular and maxillary right, first and second molars. Once the segments and the parameters were set, the outline was instantaneously drawn by the software. All design parameters worked as intended. Smooth class I inlay cavity outlines for molars with tool accessibility throughout the cavities could be obtained using the present design method.
View full abstract
-
Masako OKUMA, Masatoshi NAKAJIMA, Keiichi HOSAKA, Shima ITOH, Masaomi ...
2010 Volume 29 Issue 6 Pages
642-648
Published: 2010
Released on J-STAGE: November 26, 2010
Advance online publication: November 19, 2010
JOURNAL
FREE ACCESS
This study evaluated the effect of composite post placement and/or light-irradiation of dual-cure resin composite on adhesion to root canal dentin using the chemical activation mode of a 1-step self-etch dual-cure adhesive. Post spaces were prepared in extracted premolars. Root canal spaces were applied with Unifil Core EM Self-Etching Bond, which was chemically-polymerized, and then filled with Unifil Core EM with or without the placement of composite post. Half the specimens of each group were light-cured for 10 seconds and the other half were chemically-cured in darkness for 30 minutes. After 24 h storage, microtensile bond strengths (μTBS) at the coronal and apical regions were measured. When light-curing, placement of the composite post significantly reduced the μTBS to root canal dentin. On the other hand, when chemical-curing, there was no significant difference in μTBS between with and without placement of the composite post.
View full abstract
-
Toshiko OZAWA, Masako NAKANO, Takashi ARAI
2010 Volume 29 Issue 6 Pages
649-654
Published: 2010
Released on J-STAGE: November 26, 2010
Advance online publication: November 19, 2010
JOURNAL
FREE ACCESS
The anti-suck-back ability of five new high-speed air turbine handpiece models was evaluated in this study. First, suck-back pressure with water displacement within a glass tube was measured. Next, under three different conditions, how many on-off times it takes before fluorescent stains became visible on a piece of gauze at the exhaust vent was counted and the presence of fluorescent stains on the exhaust vents itself was examined. As a result, the water height for each part of one handpiece, the TWINPOWER TURBINE PAR-4HX-O, was below 0 mm. Except for under full emersion, this model, the TWINPOWER TURBINE PAR-4HX-O, did not have any visible fluorescence penetration to the exhaust vent even after 500 on-off switches under fume/mist conditions. Conversely, the other handpieces (Ti-Max X700L, T1 CONTROL, SYNEA TA-98CLED, GENTLE silence LUX 8000B) showed suck-back. In conclusion, the first mentioned new turbine handpiece, the TWINPOWER TURBINE PAR-4HX-O, had a possibility of no suck-back by itself. However, full immersion of the whole head of the handpiece which is not completely sealed must be avoided to prevent liquid intake.
View full abstract
-
Miho TSUJIMOTO, Toru NIKAIDO, Go INOUE, Alireza SADR, Junji TAGAMI
2010 Volume 29 Issue 6 Pages
655-660
Published: 2010
Released on J-STAGE: November 26, 2010
Advance online publication: November 19, 2010
JOURNAL
FREE ACCESS
The aim of this study was to analyze the ultrastructure of the dentin-adhesive interface using two all-in-one adhesive systems (Clearfil Tri-S Bond, TB; Tokuyama Bond Force, BF) after different acid-base challenges. Three solutions were used as acidic solutions for the acid-base challenges: a demineralizing solution (DS), a phosphoric acid solution (PA), and a hydrochloric acid solution (HCl). After the acid-base challenges, the bonded interfaces were examined by scanning electron microscopy. Thickness of the acid-base resistant zone (ABRZ) created in PA and HCl was thinner than in DS for both adhesive systems. For BF adhesive, an eroded area was observed beneath the ABRZ after immersion in PA and HCl, but not in DS. Conversely for TB adhesive, the eroded area was observed only after immersion in PA. In conclusion, although the ABRZ was observed for both all-in-one adhesive systems, its morphological features were influenced by the ingredients of both the adhesive material and acidic solution.
View full abstract
-
Tetsuya ASAI, Ryunosuke KAZAMA, Masayoshi FUKUSHIMA, Takashi OKIJI
2010 Volume 29 Issue 6 Pages
661-667
Published: 2010
Released on J-STAGE: November 26, 2010
Advance online publication: November 19, 2010
JOURNAL
FREE ACCESS
Controversy prevails over the effect of overglazing on the fracture strength of ceramic materials. Therefore, the effects of different surface finishes on the compressive fracture strength of machinable ceramic materials were investigated in this study. Plates prepared from four commercial brands of ceramic materials were either surface-polished or overglazed (
n=10 per ceramic material for each surface finish), and bonded to flat surfaces of human dentin using a resin cement. Loads at failure were determined and statistically analyzed using two-way ANOVA and Bonferroni test. Although no statistical differences in load value were detected between polished and overglazed groups (
p>0.05), the fracture load of Vita Mark II was significantly lower than those of ProCAD and IPS Empress CAD, whereas that of IPS e.max CAD was significantly higher than the latter two ceramic materials (
p<0.05). It was concluded that overglazed and polished surfaces produced similar compressive fracture strengths irrespective of the machinable ceramic material tested, and that fracture strength was material-dependent.
View full abstract
-
Yasuhiko ABE, Yohei OKAZAKI, Kyou HIASA, Isao HIRATA, Yasuhiro YOSHIDA ...
2010 Volume 29 Issue 6 Pages
668-672
Published: 2010
Released on J-STAGE: November 26, 2010
Advance online publication: November 19, 2010
JOURNAL
FREE ACCESS
The purpose of this study was to characterize the chemical interaction between titanium surfaces and the peptide RGDS(PO
3H
2)PA (P-RGD) synthesized from RGD peptide (RGD) and
o-phospho-L-serine (P-Ser), and to determine the degree of peptide immobilization on the titanium surface. X-ray photoelectron spectroscopy showed that the adsorption amount of RGD was significantly smaller than those of P-Ser and P-RGD (
p<0.05). Furthermore, although it appeared that P-RGD bonded to the surface, ultrasonic rinsing with water caused it to dissociate, releasing RGD and leaving only S(PO
3H
2)PA bonded to the surface. These findings show that although it remains difficult to obtain a stable P-RGD layer, the phosphate functional group greatly improves immobilization of the molecule on titanium surfaces.
View full abstract
-
Shunsuke BABA, Takeomi INOUE, Yoshiya HASHIMOTO, Daisuke KIMURA, Masat ...
2010 Volume 29 Issue 6 Pages
673-681
Published: 2010
Released on J-STAGE: November 26, 2010
Advance online publication: November 19, 2010
JOURNAL
FREE ACCESS
To date, there has been no study on the development of novel regimens based on the following tissue engineering principles: seeding and culturing mesenchymal stem cells (MSCs) on a scaffold before surgery or injecting cultured MSCs into a scaffold during surgery. The purpose of this study was to assess the
in vivo osteogenic ability of scaffold/MSCs implanted beneath the periosteum of the cranial bone of rats in three different sample groups: one in which MSCs were pre-seeded and cultured on a scaffold to produce the 3-D woven fabric scaffold/MSC composite using osteo-lineage induction medium, one in which cultured MSCs produced by osteo-lineage induction in cell cultivation flasks were injected into a scaffold during surgery and a control group, in which only the 3-D woven fabric scaffold was implanted. The results indicate that pre-seeding MSCs on a scaffold leads to a higher osteogenic ability than injecting cultured MSCs into a scaffold during surgery.
View full abstract
-
Shuhei HOSHIKA, Futami NAGANO, Toru TANAKA, Takatsumi IKEDA, Takahiro ...
2010 Volume 29 Issue 6 Pages
682-689
Published: 2010
Released on J-STAGE: November 26, 2010
Advance online publication: November 19, 2010
JOURNAL
FREE ACCESS
The purpose of this study was to investigate the effect of application time of colloidal platinum nanoparticles (CPN) on bond strength. Dentin surfaces were subjected to one of the following treatments: (A) Etching with 10% citric acid-3% FeCl
3 solution (10-3 solution); (B) Etching with 10-3 solution followed by applying CPN as a primer solution for 10, 20, 30, or 60 seconds; and (C) Priming with CPN for 10, 20, 30, or 60 seconds followed by etching with 10-3 solution. An acrylic rod was bonded to each treated dentin surface using 4-META/MMA-TBB resin. Bonded specimens were sectioned into beams for microtensile bond strength testing. In groups (B) and (C), highest bond strength was obtained when dentin surfaces were treated with CPN for 30 seconds. This meant that the CPN primer solution either enhanced the penetration of resin into dentin or the degree of conversion of 4-META/MMA-TBB resin. Within the limitations of this study, treatment with 0.1 mN CPN primer solution followed by 20 seconds of water rinsing resulted in high bond strength.
View full abstract
-
Sachiyo TOMITA, Shigeki YAMAMOTO, Yoshihiro SHIBUKAWA, Tadashi KANEKO, ...
2010 Volume 29 Issue 6 Pages
690-696
Published: 2010
Released on J-STAGE: November 26, 2010
Advance online publication: November 19, 2010
JOURNAL
FREE ACCESS
The aim of this study was to evaluate 4-META/MMA-TBB resin as an alternative to sling sutures for fixation of membrane to tooth in GTR in terms of its effect on tissue regeneration. Dehiscence periodontal defects were created in 6 dogs which were divided at random into two groups, 3 dogs in each group: an experimental group, in which non-absorbable or absorbable membrane was fixed to the teeth with 4-META/MMA-TBB resin; and a control group, in which sling sutures were applied to fix the two types of membrane. Histologic and histometric evaluation was carried out at 8 weeks post-operatively to determine healing response in each group. Both methods of achieving membrane fixation to tooth were effective in inhibiting epithelial migration and encouraging formation of regenerated periodontal tissues around the root surfaces. These results suggest that 4-META/MMA-TBB resin is as effective as sling sutures in achieving membrane fixation in GTR and is, moreover, easier to apply.
View full abstract
-
Andre F. REIS, Marcela R.O. CARRILHO, Eduardo GHANAME, Patricia N.R. P ...
2010 Volume 29 Issue 6 Pages
697-705
Published: 2010
Released on J-STAGE: November 26, 2010
Advance online publication: November 19, 2010
JOURNAL
FREE ACCESS
The aims of this study were to evaluate the ultimate tensile strength (UTS) and elastic modulus (
E) of adhesives, and primer/adhesive mixtures after aging for 6 months in water or oil; and to compare silver uptake patterns under the TEM. A one-step self-etching adhesive (One-up Bond F: OB), two two-step self-etching primers (SE Bond: SE and Protect Bond: CP), and two etch-and-rinse systems (Single Bond: SB and Prime&Bond NT: PB) were used. Bonding and primer solutions of self-etching systems were also mixed (SE+P and CP+P). Most adhesives presented decreased UTS after water-storage. Similar or increased UTS was observed after oil storage. Except for SB,
E values did not change after water-storage, but they increased after storage in oil. OB, CP+P and SE+P presented more silver uptake. The effects of water-storage were material-dependent, and significantly affected the mechanical properties and silver uptake patterns of adhesives.
View full abstract
-
Masahito OHIDA, Keita YODA, Naoyuki NOMURA, Takao HANAWA, Yoshimasa IG ...
2010 Volume 29 Issue 6 Pages
706-712
Published: 2010
Released on J-STAGE: November 26, 2010
Advance online publication: November 19, 2010
JOURNAL
FREE ACCESS
The static frictional coefficients (SFC) of a Co-Cr and a gold alloys were evaluated for the application of a cone crown telescope system in removable prosthesis. The SFCs of the Co-Cr alloy were lower than those of the gold alloy. The SFC of the gold alloy decreased by annealing at 85°C in air and was restored by re-polishing, although that of the Co-Cr alloy was stable irrespective of the annealing. The XPS analysis revealed the formation of a surface oxide layer on the gold alloy after annealing. The decrease in the SFC of the gold alloy may have been caused by the formation of an oxide layer on the surface due to annealing. The relationships among such factors as the retentive force, SFC and cone crown angle indicate that the angle of the Co-Cr alloy should be lower than that of the gold alloy based on the Körber’s model.
View full abstract
-
Tatsuto SHIMANE, Kazuhiko ENDO, Jing Hong ZHENG, Tomochika YANAGI, Hir ...
2010 Volume 29 Issue 6 Pages
713-720
Published: 2010
Released on J-STAGE: November 26, 2010
Advance online publication: November 19, 2010
JOURNAL
FREE ACCESS
In the present study, enamel wear against indirect composite resins was evaluated using two newly designed wear test methods: a rotating sliding wear test and a buff wear test. For the composite resins investigated in this study, their surface morphologies were examined using a scanning probe microscope after buff-polishing. After the wear tests, enamel was worn down by hard fillers that protruded from the abraded resin matrices. Notably, enamel wear was induced by composite materials with a Vickers hardness number (VHN) greater than 45 and that the amount of enamel wear increased with increasing hardness of the composite material. Therefore, 45 VHN was the critical hardness value for composite resins at which antagonistic enamel wear would occur. Besides, the
D-value obtained from the buff wear test indicated not only the relative wear resistance of the composite resin itself, but also its potential risk to induce antagonistic enamel wear.
View full abstract
-
Daisuke IROKAWA, Mikio OTA, Shigeki YAMAMOTO, Yoshihiro SHIBUKAWA, Sat ...
2010 Volume 29 Issue 6 Pages
721-730
Published: 2010
Released on J-STAGE: November 26, 2010
Advance online publication: November 19, 2010
JOURNAL
FREE ACCESS
The aim of this study was to investigate the effect of
β tricalcium phosphate (
β-TCP) particle size on recombinant human platelet-derived growth factor-BB (rhPDGF-BB)-induced regeneration of periodontal tissue in dog. The control group (rhPDGF-BB alone) was characterized by incomplete, newly formed bone. The large-particle
β-TCP (L-TCP(O))/rhPDGF-BB group showed a statistically significant increase in both new bone and cementum formation compared to the small-particle
β-TCP (S-TCP(G))/rhPDGF-BB group. These findings suggest that L-TCP(O)-particle promotes rhPDGF-BB-induced formation of bone and cementum.
View full abstract
-
Jian-Rong CHEN, Kenji OKA, Takanori KAWANO, Takaharu GOTO, Tetsuo ICHI ...
2010 Volume 29 Issue 6 Pages
731-737
Published: 2010
Released on J-STAGE: November 26, 2010
Advance online publication: November 19, 2010
JOURNAL
FREE ACCESS
The purpose of this study was to evaluate the effect of carbon dioxide laser irradiation on the performance of silane coupling agent as an adhesion promoter. The carbon dioxide laser used in this study was Opelaser 03S II, which irradiated the silane coupling agent applied on the adhesive surface of porcelain. Before and after thermal cycling, shear bond strength was measured using a universal testing machine. Without primer treatment, most of the specimens failed adhesively before reaching the end of the thermal cycling period. For the specimens irradiated with carbon dioxide laser after primer treatment, their shear bond strengths before and after thermal cycling were higher than those treated with primer only —with a significantly pronounced difference between these two groups especially after thermal cycling. Therefore, a combined surface treatment which involved silane application followed by laser treatment was feasible and efficacious for chairside porcelain repair.
View full abstract
-
Koichi SHINKAI, Yoshihisa TAIRA, Masaya SUZUKI, Chikage KATO, Junichi ...
2010 Volume 29 Issue 6 Pages
738-746
Published: 2010
Released on J-STAGE: November 26, 2010
Advance online publication: November 19, 2010
JOURNAL
FREE ACCESS
The purpose of this study was to evaluate the microtensile bond strength (MTBS) of an experimental adhesive system, which was prepared using different concentrations of calcium chloride (CaCl
2) and synthetic peptides (pA/pB). Specimens were divided into six experimental groups and two control groups. In the experimental groups, self-etching primers used in the adhesive system comprised both Primer-I (Clearfil SE Bond Primer (SEP) containing 1, 5, or 10 wt% CaCl
2) and Primer-II (SEP containing 0.1, 1, 5, or 10 wt% pA/pB). The negative control group used Primer-I containing 10 wt% CaCl
2 and Primer-II containing 10 wt% pA/pB. The positive control group used Clearfil SE Bond only. Respective primers, bonding resin, and composite paste were applied and photopolymerized individually on flattened dentin surfaces of extracted human molars. All specimens were subjected to MTBS testing (
n=20). Two-way ANOVA revealed significant differences in MTBS among CaCl
2 concentrations in Primer-I and pA/pB concentrations in Primer-II (
p<0.001), and there was a significant interaction between these two factors (
p=0.011).
View full abstract
