Journal Detail Information

1

Cite

Share

The effect of the pH of remineralized buffer solutions on dentin remineralization.

Sung Chul KIM ; Bung Duk ROH ; Il Young JUNG ; Chan Young LEE

Journal of Korean Academy of Conservative Dentistry.2007;32(2):151-161. doi:10.5395/JKACD.2007.32.2.151

Dental caries is the most common disease in the oral cavity. However, the mechanism and treatment of dental caries is not completely understood since many complex factors are involved. Especially the effect of pH on remineralization of early stage of dental caries is still controversial. In this study, dental caries in dentin was induced by using lactic acidulated buffering solutions and the loss of inorganic substance was measured. Also decalcified specimens were remineralized by three groups of solution with different pH (group of pH 4.3, 5.0, and 5.5). Then, the amount and the area of inorganic substance precipitation was quantitatively analyzed with microradiograph. Also a qualitative comparison of the normal phase, the demineralized phase, and the remineralized phase of hydroxyapatite crystal was made under SEM. The results were as follows; 1. In microradiograghic analysis, as the pH increased, the amount of remineralization in decalcified dentin tended to increase significantly. As the pH decreaced, deeper decalcification, however, occurred along with remineralization. The group of pH 5.5 had a tendency to be remineralized without demineralization (p < 0.05). 2. In SEM view, the remineralization in dentine caries occurred from the hydroxyapatite crystal surface surrounding the mesh of organic matrix, and eventually filled up the demineralized area. 3. 5 days after remineralization, hydroxyapatite crystal grew bigger with deposition of inorganic substance in pH 4.3 and 5.0 group, and the crystal in the remineralized area appeared to return to normal. After 10 days, the crystals in group of pH 4.3 and 5.0, which grew bigger after 5 days of remineralization, turned back to their normal size, but in group of pH 5.5, some crystals were found to double their size. In according to the results of this experiment, the decalcifying and remineralizing process of dentine is neither simple nor independent, but a dynamic process in which decalcification and remineralization occur simultaneously. The remineralization process occurred from the hydroxyapatite crystal surface.
Dental Caries ; Dental Enamel ; Dentin* ; Durapatite ; Hydrogen-Ion Concentration* ; Mouth

2

Cite

Share

A study of insertion depth of gutta percha cones after shaping by Ni-Ti rotary files in simulated canals.

Hyun Gu CHO ; Yun Chan HWANG ; In Nam HWANG ; Won Mann OH

Journal of Korean Academy of Conservative Dentistry.2007;32(6):550-558. doi:10.5395/JKACD.2007.32.6.550

The purpose of this study was to evaluate the insertion depth of several brands of master gutta percha cones after shaping by various Ni-Ti rotary files in simulated canals. Fifty resin simulated J-shape canals were instrumented with ProFile, ProTaper and HEROShaper. Simulated canals were prepared with ProFile .04 taper #25 (n = 10), .06 taper #25 (n = 10), ProTaper F2 (n = 10), HEROShaper .04 taper #25 (n = 10) and .06 taper #25 (n = 10). Size #25 gutta percha cones with a .04 & .06 taper from three different brands were used: DiaDent; META; Sure-endo. The gutta percha cones were selected and inserted into the prepared simulated canals. The distance from the apex of the prepared canal to the gutta percha cone tip was measured by image analysis program. Within limited data of this study, the results were as follows 1. When the simulated root canals were prepared with HEROShaper, gutta-percha cones were closely adapted to the root canal. 2. All brands of gutta percha cones fail to go to the prepared length in canal which was instrumented with ProFile, the cones extend beyond the prepared length in canal which was prepared with ProTaper. 3. In canal which was instrumented with HEROShaper .04 taper #25, Sure-endo .04 taper master gutta percha cone was well fitted (p < 0.05). 4. In canal which was instrumented with HEROShaper .06 taper #25, META .06 taper master gutta percha cone was well fitted (p < 0.05). As a result, we concluded that the insertion depth of all brands of master gutta percha cone do not match the rotary instrument, even though it was prepared by crown-down technique, as recommended by the manufacturer. Therefore, the master cone should be carefully selected to match the depth of the prepared canal for adequate obturation.
Dental Pulp Cavity ; Gutta-Percha*

3

Cite

Share

Surface roughness and color stability of various composite resins.

Sung Yi LEE ; Hyeon Cheol KIM ; Bock HUR ; Jeong Kil PARK

Journal of Korean Academy of Conservative Dentistry.2007;32(6):542-549. doi:10.5395/JKACD.2007.32.6.542

The purpose of this study was to evaluate the difference in the surface roughness after polishing and to evaluate the difference in color stability after immersion in a dye solution among four types of composite resin materials. Four light-polymerized composite resins (Shade A2) with different sized filler content (a nanofilled, a hybrid, a microfilled, a flowble) were used. Average surface roughness (Ra) was measured with a surface roughness tester (Surftest Formtracer) before and after polishing with aluminum oxide abrasive discs (Super-Snap). Color of specimens before and after staining with 2% methylene blue solution were measured using spectrophotometer (CM-3700d) with SCI geometries. The results of Ra and DeltaE were analyzed by one-way analysis of variance (ANOVA), a Scheffe multiple comparison test and Student t-test (p = 0.05). After polishing, Ra values were decreased regardless of type of composite resins. In surface roughness after polishing and color stability after staining, nanofilled composite resin was not different with other composite resins except flowable resins.
Aluminum Oxide ; Composite Resins* ; Humans ; Immersion ; Methylene Blue ; Silicone Elastomers

4

Cite

Share

Comparison of shaping ability using various Nickel-Titanium rotary files and hybrid technique.

Jung Won KIM ; Jeong Kil PARK ; Bock HUR ; Hyeon Cheol KIM

Journal of Korean Academy of Conservative Dentistry.2007;32(6):530-541. doi:10.5395/JKACD.2007.32.6.530

Currently, various Nickel-Titanium rotary files are used in endodontic treatment, but there is no one perfect system that can be applied to any clinical situation. Therefore, the combined uses of various file systems which can emphasize the advantages of each system are introduced as hybrid instrumentation. The ProTaper system is efficient in body shaping and apical pre-enlargement but is reported to have more possibility of transportation and produce more aberrations and deformation in more or less severe curved canals. Recently, new ProTaper system (ProTaper Universal) with different configuration and cross-sectional design to overcome the week points of ProTaper have been marketed. The purpose of this study was to compare and evaluate the shaping abilities of ProTaper, ProTaper Universal system, and two hybrid methods using S-series of ProTaper Universal and Hero Shaper or ProFile. The time lapses for instrumentation were measured and the used files were inspected for distortion. The pre- and post-instrumented root canals were scanned and superimposed to evaluate the aberrations and reduction of root canal curvature and change of radius of canal curvature. The increased canal width and apical centering ratio were calculated at 1, 2, 3, 4 and 5 mm levels from apical foramen. Under the conditions of this study, the ProTaper Universal seems to have better shaping ability than ProTaper in terms of instrumented width and instrumentation time. It may be suggested that the ProTaper Universal system is efficient as much as hybrid instrumentation using ProTaper and other constant-tapered NiTi file systems in highly experienced operators.
Dental Pulp Cavity ; Radius ; Tooth Apex ; Transportation ; Two-Hybrid System Techniques

5

Cite

Share

Comparison of apical sealing ability of continuous wave of obturation technique using EndoTwinn and System B.

Hyun Ju SHIN ; Jeong Kil PARK ; Bock HUR ; Hyeon Cheol KIM

Journal of Korean Academy of Conservative Dentistry.2007;32(6):522-529. doi:10.5395/JKACD.2007.32.6.522

The purpose of this study was to compare the apical leakage of the root canal filled with the System B and the EndoTwinn (the combined application of heat and ultrasonic vibration). Sixty extracted premolars with straight root were cleaned and shaped to size 35. Group SB was obturated using System B and Group ET was filled with EndoTwinn. A size 35 of 0.06 tapered gutta- percha and Adseal were used and the plugger which could be introduced to 4 mm short of working length was selected in the obturation procedure. As the positive control, Group PC was not filled. In Group SB, ET and PC, all external surfaces of each tooth were coated with nail varnish leaving only 1 mm area around the apical foramen. In the negative control of Group NSB and Group NET, all of external tooth surface including apical foramen was coated with the nail varnish. The specimens were immersed in methylene blue dye solution for 2 days. Then the specimens were sectioned at each 1 mm from apex to 5 mm level. The final score of one specimen was given by summing up of the points at all levels. The dye leakage of Group ET was significantly less than that observed in Group SB (p < 0.05). And the frequency of gutta-percha pulling out from root canal when the plugger was removed was more often with the System B than with EndoTwinn but there was no significant difference.
Bicuspid ; Dental Pulp Cavity ; Gutta-Percha ; Hot Temperature ; Methylene Blue ; Paint ; Tooth ; Tooth Apex ; Ultrasonics

6

Cite

Share

Expression of P2X3 and its colocalization with trpv1 in the human dental pulp.

Young Kyung KIM ; Sung Kyo KIM

Journal of Korean Academy of Conservative Dentistry.2007;32(6):514-521. doi:10.5395/JKACD.2007.32.6.514

The purinoreceptor, P2X3 is a ligand-gated cation channel activated by extracellular ATP. It has been reported that ATP can be released during inflammation and tissue damage, which in turn may activate P2X3 receptors to initiate nociceptive signals. However, little is known about the contribution of P2X3 to the dental pain during pulpal inflammation. Therefore, the purpose of this study was to investigate the expression of P2X3 and its colocalization with TRPV1 to understand the mechanism of pain transmission through P2X3 in the human dental pulp with double labeling immunofluorescence method. In the human dental pulp, intense P2X3 immunoreactivity was observed throughout the coronal and radicular pulp. Of all P2X3-positive fibers examined, 79.4% coexpressed TRPV1. This result suggests that P2X3 along with TRPV1 may be involved in the transmission of pain and potentiation of noxious stimuli during pulpal inflammation.
Adenosine Triphosphate ; Dental Pulp* ; Fluorescent Antibody Technique ; Humans* ; Inflammation ; Receptors, Purinergic P2X3

7

Cite

Share

The change of the configuration of hydroxyapatite crystals in enamel by changes of pH and degree of saturation of lactic acid buffer solution.

Young Eui CHON ; Il Young JUNG ; Bung Duk ROH ; Chan Young LEE

Journal of Korean Academy of Conservative Dentistry.2007;32(6):498-513. doi:10.5395/JKACD.2007.32.6.498

Since it was reported that incipient enamel caries can be recovered, previous studies have quantitatively evaluated that enamel artificial caries have been remineralized with fluoride, showing simultaneously the increase of width of surface layer and the decrease of width of the body of legion. There is, however, little report which showed that remineralization could occur without fluoride. In addition, the observations on the change of hydroxyapatite crystals also have been scarcely seen. In this study, enamel caries in intact premolars or molars was induced by using lactic acidulated buffering solutions over 2 days. Then decalcified specimens were remineralized by seven groups of solutions using different degree of saturation (0.212, 0.239, 0.301, 0.355) and different pH (5.0, 5.5, 6.0) over 10 days. A qualitative comparison to changes of hydroxyapatite crystals after fracturing teeth was made under SEM (scanning electron microscopy) and AFM (atomic force microscopy). The results were as follows: 1. The size of hydroxyapatite crystals in demineralized area was smaller than the normal ones. While the space among crystals was expanded, it was observed that crystals are arranged irregularly. 2. In remineralized enamel area, the enlarged crystals with various shape were observed when the crystals were fused and new small crystals in intercrystalline spaces were deposited. 3. Group 3 and 4 with higher degree of saturation at same pH showed the formation of large clusters by aggregation of small crystals from the surface layer to the lesion body than group 1 and 2 with relatively low degree of saturation at same pH did. Especially group 4 showed complete remineralization to the body of lesions. Group 5 and 6 with lower pH at similar degree of saturation showed remineralization to the body of lesions while group 7 didn't show it. Unlike in Group 3 and 4, Group 5 and 6 showed that each particle was densely distributed with clear appearance rather than crystals form clusters together.
Bicuspid ; Dental Enamel* ; Durapatite* ; Fluorides ; Hydrogen-Ion Concentration* ; Lactic Acid* ; Microscopy, Atomic Force ; Microscopy, Electron, Scanning ; Molar ; Tooth

8

Cite

Share

Comparison of apical sealing efficacies using different plugging depth in continuous wave of obturation technique.

Sang Jin LEE ; Jeong Kil PARK ; Bock HUR ; Hyeon Cheol KIM

Journal of Korean Academy of Conservative Dentistry.2007;32(6):491-497. doi:10.5395/JKACD.2007.32.6.491

The purpose of this study was to compare apical sealing ability of continuous wave canal filling technique according to various heat source plugging depths. Eighty one extracted human premolars with straight root were cleaned and shaped to size 35 using .06 taper rotary NiTi file. After cleansing and shaping, the teeth were divided into 5 groups following the heat source probing depths from the apex; 3, 4, 5, 6 and 7 mm. All specimens were filled using E&Q plus with #35 / .06 tapered gutta-percha cone. The positive control teeth were not filled. All teeth were coated with nail varnish except the apical 1 mm around the apical foramen. Negative control teeth were completely sealed include the apical foramen. All specimens were immersed in 1% methylene blue solution for 72 hours. Then the specimens were sectioned horizontally at 1, 2 and 3 mm from the root apex. Each sectioned surface was photographed using a digital camera attached to the stereomicroscope at 12.5 x 2.5 fold magnification. All points at 1, 2 and 3 mm were summed as final score of one specimen. Statistical analysis of the collected data was performed. Under the condition of this study, there was no significant difference between the heat source plugging depths of 3, 4, 5, 6 and 7 mm in apical sealing ability. All of apical heat source plugging depth from 3 to 7 mm including Buchanan's protocol -from 5 to 7 mm- seems to be acceptable in clinical application.
Bicuspid ; Gutta-Percha ; Hot Temperature ; Humans ; Methylene Blue ; Paint ; Tooth ; Tooth Apex

9

Cite

Share

Slumping tendency and rheological property of flowable composites.

In Bog LEE ; Sun Hong MIN ; Sun Young KIM ; Byung Hoon CHO ; Seung Ho BACK

Journal of Korean Academy of Conservative Dentistry.2009;34(2):130-136. doi:10.5395/JKACD.2009.34.2.130

The aim of this study was to develop a method for measuring the slumping resistance of flowable resin composites and to evaluate the efficacy using rheological methodology. Five commercial flowable composites (Aelitefil flow:AF, Filtek flow:FF, DenFil flow:DF, Tetric flow:TF and Revolution:RV) were used. Same volume of composites in a syringe was extruded on a glass slide using a custom-made loading device. The resin composites were allowed to slump for 10 seconds at 25degrees C and light cured. The aspect ratio (height/diameter) of cone or dome shaped specimen was measured for estimating the slumping tendency of composites. The complex viscosity of each composite was measured by a dynamic oscillatory shear test as a function of angular frequency using a rheometer. To compare the slumping tendency of composites, one way-ANOVA and Turkey's post hoc test was performed for the aspect ratio at 95% confidence level. Regression analysis was performed to investigate the relationship between the complex viscosity and the aspect ratio. The results were as follows. 1. Slumping tendency based on the aspect ratio varied among the five materials (AF < FF < DF < TF < RV). 2. Flowable composites exhibited pseudoplasticity in which the complex viscosity decreased with increasing frequency (shear rate). AF was the most significant, RV the least. 3. The slumping tendency was strongly related with the complex viscosity. Slumping resistance increased with increasing the complex viscosity. The slumping tendency could be quantified by measuring the aspect ratio of slumped flowable composites. This method may be applicable to evaluate the clinical handling characteristics of flowable composites.
Composite Resins ; Glass ; Handling (Psychology) ; Light ; Syringes ; Viscosity

10

Cite

Share

Histological evaluation of direct pulp capping with DSP-derived synthetic peptide in beagle dog.

Jae Hoon KIM ; Jun Bae HONG ; Bum Soon LIM ; Byeong Hoon CHO

Journal of Korean Academy of Conservative Dentistry.2009;34(2):120-129. doi:10.5395/JKACD.2009.34.2.120

The purpose of this study was to investigate the pulpal response to direct pulp capping with dentin sialoprotein (DSP)-derived synthetic peptide in teeth of dogs, and to compare its efficacy to capping substances Ca(OH)2 and white mineral trioxide aggregate (WMTA). A total of 72 teeth of 6 healthy male beagle dogs were used. The mechanically exposed pulps were capped with one of the following: (1) DSP-derived synthetic peptide (PEP group); (2) Ca(OH)2 (CH group); (3) a mixture paste of peptide and Ca(OH)2 (PEP+CH group); or (4) white MTA (WMTA group). The access cavity was restored with a reinforced glass ionomer cement. Two dogs were sacrificed at each pre-determined intervals (2 weeks, 1 month, and 3 months). After the specimens were prepared for standard histological processing, sections were stained with hematoxylin and eosin. Under a light microscope, inflammatory response and hard tissue formation were evaluated in a blind manner by 2 observers. In the PEP group, only 3 of 17 specimens showed hard tissue formation, indication that the DSP-derived synthetic peptide did not induce proper healing of the pulp. Compared with the CH group, the PEP group demonstrated an increased inflammatory response and poor hard tissue formation. The CH and WMTA groups showed similar results for direct pulp capping in mechanically exposed teeth of dogs.
Acrylic Resins ; Aluminum Compounds ; Animals ; Calcium Compounds ; Calcium Hydroxide ; Dental Pulp Capping ; Dentin ; Dogs ; Drug Combinations ; Eosine Yellowish-(YS) ; Extracellular Matrix Proteins ; Glass Ionomer Cements ; Glutamates ; Guanine ; Hematoxylin ; Humans ; Light ; Male ; Oligopeptides ; Oxides ; Phosphoproteins ; Sialoglycoproteins ; Silicates ; Silicon Dioxide ; Tooth ; Pemetrexed

DISPLAY OPTIONS

Cite

Share

Cite

Share

Cite

Share

Cite

Share

Cite

Share

Cite

Share

Cite

Share

Cite

Share

Cite

Share

Cite

Share