Protein microarray or protein chips is potentially powerful tools for analysis of protein-protein interactions. APin cDNA was previously identified and cloned from a rat odontoblast cDNA library. The purpose of this study was to investigate the APin-protein interactions during ameloblast differentiation. Protein microarray was carried with recombinant APin protein and MEF2, Aurora kinase A, BMPR-IB and EF-hand calcium binding protein were selected among 74 interacting proteins. Immortalized ameloblast cells (ALCs) were transfected with pCMV-APin construct and U6-APin siRNA construct. After transfection, the expression of the mRNAs for four proteins selected by protein micoarrays were assessed by RT-PCR. The results were as follows: 1. APin expression was increased and decreased markedly after its over-expression and inactivation, respectively. 2. Over-expression of the APin in the ALCs markedly down-regulated the expression of MEF2 and Aurora kinase A, whereas their expression remained unchanged by its inactivation. 3. Expression of BMPR-IB and EF-hand calcium binding protein were markedly increased by the overexpression of the APin in the ALCs, whereas expression of BMPR-IB remained unchanged and expression of EF-hand calcium binding protein was markedly decreased by its inactivation. These results suggest that APin plays an important role in ameloblast differentiation and mineralization by regulating the expression of MEF2, Aurora kinase A, BMPR-IB and EF-hand calcium binding protein.
Ameloblasts ; Animals ; Aurora Kinase A ; Calcium ; Carrier Proteins ; Clone Cells ; DNA, Complementary ; Gene Library ; Odontoblasts ; Protein Array Analysis* ; Rats ; RNA, Messenger ; RNA, Small Interfering ; Transfection

The purpose of this study was to evaluate the bond strength of a new Single step system with different curing mode composites, and to evaluate the effect of the intermediate resins which have different hydrophilicity on bonding ability by means of the micro shear bond testing and TEM examination for the adhesive interface. The adhesive used in this study was an experimental single step system (Bisco Inc., Schaumburg, IL). Experimental groups were produced by using six kinds of intermediate resin having different hydrophilicity that was hydrophilic, hydrophobic and most hydrophobic resin and as filled or not after applying adhesive. Each experimental group was further divided into two subgroups whether the adhesive was light cured or not. Dual cured composite (Bis Core, Bisco Ltd., Schaumburg, IL) was placed on the adhesive layer as light cure or self cure mode. The results of bond strength were statistically analyzed using one way ANOVA and multiple comparisons are made using Tukey's test at alpha < 0.05 level. The results of this study were as follows; 1. The application of intermediate resin did not increase the bond strength for light cured composite. 2. The bond strength of an experimental adhesive with self cured composite was significantly increased by the application of intermediate resin layer. 3. The bond strength of adhesive was irrespective of the cure or not of itself before intermediate resin layer applied. 4. As applied hydrophilic resin layer was, the initial bond strength was higher than both hydrophobic and most hydrophobic one used but there was no significance. Using a single step adhesive with dual/self cured composite, the incompatibility between both of them should be solved by the application of intermediate hydrophobic resin to reduce the adhesive permeability. However, Single step adhesive can be used in the light cured composite restoration without any decrease of the initial bond strength.
Adhesives* ; Hydrophobic and Hydrophilic Interactions* ; Permeability

The purpose of this study was to compare the marginal microleakage of different 2-step adhesive systems in Class V cavities prepared with different diamond points. Forty Class V cavities were prepared with two different (coarse or fine) diamond points on cervical third of extracted molars. The occlusal and gingival margin of cavities was located in enamel and dentin, respectively. They were divided into one of four equal groups (n = 10) and ; Group 1-prepared with coarse diamond point (EX-41), restored with Single Bond and Z 250, Group 2-prepared with fine diamond piont (TF-21F), restored with Single Bond and Z 250, Group 3-prepared with coarse diamond point (EX-41), restored with Clearfil SE Bond and Clearfil AP-X, Group 4-prepared with fine diamond point (TF-21F), restored with Clearfil SE Bond and Clearfil AP-X. Specimens were thermocycled, immersed in a 2% methylene blue solution for 24 hours, and bisected longitudinally. They were observed leakages at enamel and dentinal margins. Data were analyzed using Mann-Whitney and Wilcoxon signed ranked test. In this study, marginal microleakage of Single Bond was not affected by type of diamond points. But Clearfil SE Bond showed higher marginal microleakage at both enamel and dentinal margin when Class V cavity was prepared with coarse diamond point.
Adhesives* ; Dental Enamel ; Dentin ; Diamond ; Methylene Blue ; Molar

The objective of this study is to evaluate the effect of an additional application of bonding resin on the bond strength of resin luting cements in both the light-cure (LC) and self-cure (SC) modes by means of the microTBS tests. Three combinations of One-Step Plus with Choice, Single Bond with Rely X ARC, and One-Up Bond F with Bistite II were used. D/E resin and Pre-Bond resin were used for the additional application. Twelve experimental groups were made. Three mandibular 3rd molars were used in each group. Indirect composite blocks were cemented on the tooth surface. 1 x 1 mm2 dentin-composite beam for microTBS testing were made and tested. When total-etching dentin adhesives were used, an additional application of the bonding resin increased the bond strength (P < 0.05). However, this additional application didn't influence the bond strength of self-etching dentin adhesives (P > 0.05). In conclusion, the results suggest that an additional application of the bonding resin increases bond strength and enhances quality of bonding when using total-etching dentin adhesives.
Adhesives ; Dentin ; Dentin Permeability ; Molar ; Resin Cements* ; Tooth

The aim of this study was to evaluate the radiopacity and cytotoxicity of three resin-based (AH 26, EZ fill and AD Seal), a zinc oxide-eugenol-based (ZOB Seal), and a calcium hydroxide-based (Sealapex) root canal sealers. Specimens, 10 mm in diameter and 1 mm in thickness, were radiographed simultaneously with an aluminum step wedge using occlusal films, according to ISO 6876/2001 standards. Radiographs were digitized, and the radiopacity of sealers was compared to the different thicknesses of the aluminum step wedge, using the Scion image software. Using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, the cytotoxicity of each material was determined in immortalized human periodontal ligament (IPDL) cells. The results demonstrated that EZ fill was the most radiopaque sealer, while Sealapex was the least radiopaque (p < 0.05). AH 26, AD Seal and ZOB Seal presented intermediate radiopacity values. All the materials evaluated, except for Sealapex, presented the minimum radiopacity required by ISO standards. The cell viabilities of resin-based root canal sealers were statistically higher than that of other type of root canal sealers through the all experimental time. Further, EZ fill showed statistically lower cell viability in 24 and 48 hours compared to AD Seal and in 72 hours compared to all other resin-based root canal sealers. However, there was no correlation between the radiopacity and cytotoxicity of three resin-based root canals sealers (p > 0.05). These results indicate that resin-based root canal sealer is more biocompatible and has advantage in terms of radiopacity.
Aluminum ; Calcium ; Cell Survival ; Dental Pulp Cavity* ; Humans ; Periodontal Ligament ; Zinc

The most scientific and reliable method for deciding the tooth color is the instrumental measurement. However, such color measuring instrument shows the difference of the measuring value according to the diversified measuring condition. This study was conducted to evaluate what effect of the labial surface irregularity of the tooth to the result of the color measured by spectrometer. 11 models of the teeth were made by injecting the A2 shade Luxatemp Automix Plus (DMG, Germany) into the impression acquired from 11 adults. Standard disk samples (15 mm diameter, 7 mm thickness) were made with same material. CIE L*a*b* value was measured at the incisal, central, and gingival area of the central incisor, lateral incisor, canine and first premolar using Specbos 2100 (JETI, Germany) spectrometer. Color difference was calculated between labial surface and standard samples. Among all models of the teeth, L* and b* value showed the reducing tendency as they go toward the gingival area, but a* value showed the increasing tendency. Color difference between model teeth and standard samples showed the most difference at the incisal area, but the gingival area showed the least difference. And the canine showed the least color difference from the comparison of standard sample, and the central incisor showed the highest difference (p < 0.01). Although the visually detectable difference of the measuring value showed notably depending on the type and measured area (p < 0.05), L* and a* value showed notable differences depending more on the measured areas than on the type of the teeth.
Adult ; Bicuspid ; Humans ; Incisor ; Tooth*

The purpose of this study was to investigate whether rhBMP-2 (BMP2) could induce synergistic effect with Pro-Root(R) MTA (MTA) in pulpotomized teeth in the rats. Healthy upper first molars from thirty-two, 10 weeks old, Sprague-Dawley rats were used for this investigation. The molars were exposed with round bur, and light pressure was applied with sterilized cotton to control hemorrhage. 1.2 grams of MTA cement was placed in right first molars as a control group. In left first molars, 1 microg of BMP2 was additionally placed on exposed pulps with MTA. All cavities were back-filled with light-cured glass-ionomer cements. The rats were sacrificed after 2 weeks and 7 weeks, respectively. Then histologic sections were made and assessed by light microscopy. Data were statistically analyzed via student t-test with SPSSWIN 12.0 program (p < 0.05). Inflammation observed in 2 weeks groups were severe compared to the 7 weeks groups. But the differences were not statistically significant. BMP2-addition groups had less inflammation than MTA groups in both periods, though these differences were also not statistically significant. In conclusion, the combination of BMP2 and MTA showed no differences with MTA only for pulpotomy of rat teeth.
Animals ; Hemorrhage ; Humans ; Inflammation ; Microscopy ; Molar ; Pulpotomy ; Rats* ; Rats, Sprague-Dawley ; Tooth* ; Pemetrexed

The purpose of this study was to compare the sealing ability of root canal obturation with or without the treatment of smear layer. Eighty extracted human teeth with one canal were selected. Instrumentation was performed with crown-down technique. After instrumentation, root canals of the NaOCl group and NaOCl-6 group were irrigated with 3% NaOCl. EDTA group and EDTA-6 group were irrigated with 17% EDTA. Then all teeth were obturated using continuous wave obturation technique. NaOCl group and EDTA group were immersed in methylene blue solution for 84hours. NaOCl-6 group and EDTA-6 group were immersed in methylene blue solution for 6months. The teeth were sectioned at 1.5 mm (Level 1), 3.0 mm (Level 2) and 4.5 mm (Level 3) from the root apex. The length of dye-penetrated interface and the circumferential length of canal at each level were measured using Sigma-Scan Pro 5.0. 1. The mean leakage ratio was decreased cervically. 2. NaOCl group showed higher mean leakage ratio than EDTA group at each level. But there was significant difference at level 1 only (p < 0.05). 3. NaOCl-6 group showed higher mean leakage ratio than EDTA-6 group at each level. But there was significant difference at level 1 only (p < 0.05). 4. NaOCl-6 group showed higher mean leakage ratio than NaOCl group at each level. But there was significant difference at level 1 only (p < 0.05). 5. EDTA-6 group showed higher mean leakage ratio than EDTA group at each level. But there was no significant difference. 6. In NaOCl group and NaOCl-6 group, scanning electron micrographs of tooth sections generally covered with smear layer. In EDTA group and EDTA-6 group, tooth sections showing the penetration of sealers to opened dentinal tubules. The results suggest that removal of smear layer was effective to reduce the apical microleakage of the root canal.
Dental Pulp Cavity ; Dentin ; Edetic Acid ; Humans ; Methylene Blue ; Root Canal Obturation ; Smear Layer* ; Tooth

The purposes of this study were to assess the accuracy of measurements in pre-enlarged canals with small instruments and to compare the accuracies, in enlarged canal, with small size instruments and instruments that match the actual canal diameter using Root ZX, Bingo1020, SmarPex, and e-Magic Finder. Ten extracted teeth were embedded in an alginate model made for testing apex locators. A size 10 file was placed into the root canal until the tip of the file reached the plane of the major diameter of the foramen under a dental operating microscope at the 25 x magnification. The measurement was done with digital caliper and defined as actual length. Electronic length measurement with a size 10 file in pre-enlarged canal was done by reading the index indicating Apex of each device to gain a definite value. After completion of canal enlargement to a size 45 file, each difference between actual length and electric measurement value with a size 10 and 40 files in enlarged canal was recorded as L10 and L40. The one-way ANOVA and Scheffe's multiple range tests were computed for analyze the differences among the four apex locators in the same group. The Student's t-test between L10 and L40 of each locator was done. The accuracies of electronic measurements were significantly different among the 4 devices. The file size made no difference on the accuracy of electronic measurement in enlarged canal with same device. The e-Magic Finder was the most accurate device among the 4 apex locators used in this study.
Dental Pulp Cavity ; Tooth

The objective of this study was to investigate the effect of excessive occlusal loading on stress distribution on four type of cervical lesion, using a three dimensional finite element analysis (3D FEA). The extracted maxillary second premolar was scanned serially with Micro-CT. The 3D images were processed by 3D-DOCTOR. ANSYS was used to mesh and analyze 3D FE model. Four different lesion configurations representative of the various types observed clinically for teeth were studied. A static point load of 500N was applied to the buccal and lingual cusp (Load A and B). The principal stresses in lesion apex, and vertical sectioned margin of cervical wall were analyzed. The results were as follows 1. The patterns of stress distribution were similar but the magnitude was different in four types of lesion. 2. The peak stress was observed at mesial corner and also stresses concentrated at lesion apex. 3. The compressive stress under load A and the tensile stress under load B were dominant stress. 4. Under the load, lesion can be increased and harmful to tooth structure unless restored.
Bicuspid ; Finite Element Analysis* ; Tooth