Journal Detail Information

1

Cite

Share

Perspective of endodontic sealers based on calcium silicate

Korean Journal of Dental Materials.2022;49(4):243-250. doi:10.14815/kjdm.2022.49.4.243

Calcium silicate based sealers (CSBS) were introduced under the background of a calcium silicate based hydrophilic cement (mineral trioxide aggregate: MTA), composed by tricalcium and dicalcium silicate. Inspired by the excellent sealing ability and biocompatibility of MTA, the sealers establish a biological point of view on the canal obturation. There is no doubt that premixed calcium silicate based sealers has gained wide acceptance in clinical application, but unstable setting time, slight solubility and retreatability of the CSBS might compromise the usage and value of the new class of endodontics sealers. Further clinical studies are required to improve the properties of the calcium silicate based sealers.

2

Cite

Share

Preparation and characterization of uniform NiTi-O nanotubes on NiTi alloy

Kyung-Suk MOON ; Ji-Myung BAE ; Seunghan OH ; Eun-Joo CHOI

Korean Journal of Dental Materials.2022;49(4):233-242. doi:10.14815/kjdm.2022.49.4.233

This study aimed to optimize the cleaning process of the anodized specimens for fabricating clean NiTi-O nanotubes exhibiting visible light-mediated antibacterial activity at the surface of NiTi alloy. The cleaning process of the anodized specimens tested in this study was composed of two steps. The First step included two washing solvents (distilled water and heptane) with different washing times (1, 3, and 5 min) and temperatures (25 and 80 ℃), and the second step was treated by ultrasonicator (1, 3, and 5 min). From the results of FE-SEM observation, clean and uniform nanotubes (length: 600±80 nm, diameter: 52 ±5 nm) at the surface of NiTi alloy were observed on the condition of 5 min of washing in heptane at 25 ℃ and then 3 min of ultrasonication. Thin film XRD analysis resulted that the brookite TiO 2 crystal structure being detected in the anodized specimen. Furthermore, the live-dead assay resulted that there was no significant difference among the cell viability numbers of hMSCs cultured on a cell culture dish (control), NiTi alloy, and NiTi-O nanotubes (P>0.05). Therefore, the optimized cleaning process of the anodized NiTi alloy is expected to be more feasible for the NiTi alloy-based implant surface treatment technology.

3

Cite

Share

Antibacterial effect of biodegradable gelatin methacryloyl loaded with ginger rhizome extract

Regina Guadalupe ARBIZÚ-TRIGUEROS ; Seo-Young KIM ; Yu-Kyoung KIM ; Yong-Seok JANG ; Ae-Jin CHOI ; Tae-Sung BAE ; Min-Ho LEE

Korean Journal of Dental Materials.2022;49(4):213-232. doi:10.14815/kjdm.2022.49.4.213

Gelatin methacryloyl 3d mesh mimics the natural extracellular matrix which allow loading as promising drug delivery systems.However, insufficient mechanical and degradation properties remain the biggest obstacle for this material application. In this study, a modified hydrogel with natural phytochemical was developed to improve the antibacterial effect by the addition of ginger extract, a natural spicy used in traditional medicine. GelMA hydrogels with ginger extract were fabricated and their chemical and morphological characteristics were analyzed by Fourier transformer infrared spectroscopy and scanning electron microscopy, structural characteristic were evaluated by compressive test and surface wettability analysis. S. mutans, S. aureus and P. gingivalis were used to confirm the antibacterial effect of the modified hydrogels. The FT-IR spectra of the hydrogels modified with ginger presented an increase in intensity of some peaks in comparison with the 10% GelMA hydrogel. The pores of ginger-modified hydrogels decreased it size which affected the hydrogels physical properties, decreasing the compressive modulus and increasing the durability, swelling ratio and, hydrophobicity of the surface. The ginger-modified hydrogels exhibited excellent antibacterial properties against S. mutans and S. aureus at high concentrations of ginger extract, while P. gingivalis presented a higher sensitivity at all tested concentrations. Hence, this study concludes that ginger-modified GelMA hydrogels presented better antibacterial effect, durability over time and, swelling stability.

4

Cite

Share

A study on coating of collagen-containing hydroxyapatite on titanium using electrochemical deposition method

Byunghan CHOI ; Yeong-Joon PARK ; Ho-Jun SONG

Korean Journal of Dental Materials.2022;49(4):199-212. doi:10.14815/kjdm.2022.49.4.199

In this study, a biomimetic coating in which hydroxyapatite (HAp) and collagen (Col), the major components of bone, were coated together on titanium was performed using the ECD method. The polished CP-Ti (commocially pure–titanium) disks (Ti-As), and the roughened CP-Ti disks (Ti-R) fabricated by anodic oxidation method were prepared. An electrolyte (E) was prepared by mixing Ca(NO 3 ) 2 and NH 4 H 2 PO 4 . Collagen-contaiing electrolyte (ECol) was prepared by adding collagen (Type-I) to E electrolyte. A pulse-type negative electric current of -5 mA, -10 mA, and -15 mA was applied to the titanium specimens, respectively.The temperature of electrolyte solution was maintained at 37℃. The fabricated specimens were named to Ti-As-E-5, Ti-As-E-10, Ti-As-E-15, Ti-As-ECol-5, Ti-As-ECol-10, Ti-As-ECol-15, Ti-R-E-5, Ti-R-E-10, Ti-R-E-15, Ti-R-ECol-5, Ti-R-ECol-10, and Ti-R-ECol-15, respectively. The nanorod-shaped crystallites were evenly formed on the surface of Ti-As-E groups. The length of nanorods on Ti-As-ECol groups was shorter than that on Ti-As-E groups. A low crystalline HAp structure was detected in X-ray diffraction (XRD) patterns of Ti-As-E groups. For Ti-As-ECol groups, the HAp structure was confirmed by analysis of the selected area electron diffraction (SAED) patterns obtained from a transmission electron microscope (TEM). Fourier-transform infrared spectroscopy (FT-IR) spectra of Ti-As-ECol groups showed the amide peaks assigned to collagen and related to carbonate apatite. Similarly to the Ti-As specimens, HAp crystallites were coated on Ti-R-E and Ti-R-ECol groups and their surface roughness was maintained. It is expected that the results of this study could be applied to the development of a biomimetic surface treatment method for titanium implants.

5

Cite

Share

The stimulatory effect of Angelica tenuissima Nakai in osteoblastic/odontoblastic differentiation of human periodontal ligament stem cells

Won-Jong PARK ; Youn Ho HAN

Korean Journal of Dental Materials.2022;49(4):187-198. doi:10.14815/kjdm.2022.49.4.187

Angelica tenuissima Nakai (ATN) is an herbal medicine used to treat toothache, headaches, and cold symptoms. However, the therapeutic effects of ATN have not been thoroughly identified. The purpose of this research was to explore the effect of ATN in osteo/odontoblastic differentiation of human periodontal ligament stem cells (hPDLSCs). The influences of ATN on the differentiation and proliferation of hPDLSCs were evaluated using alizarin red S staining, real-time PCR, western blot and MTT assay. ATN promoted osteo/odontoblastic differentiation of hPDLSCs, accelerated mineral nodule formation in vitro, and displayed no toxicity at higher concentrations. The mRNA expression levels of alkaline phosphatase (ALP), type I collagen (COL1), osteopontin (OPN), dentin matrix acidic phosphoprotein 1 (DMP-1), and dentin sialophosphoprotein (DSPP) in hPDLSCs and the protein levels of osteocalcin (OCN), DSPP, DMP-1, and Runx2 were significantly higher after ATN treatment. HEK293 cells overexpressing the osterix (OSX) gene and treated with ATN (100 µg/mL) showed an increase in BSP promoter activity.Those results suggest that ATN enhances the osteo/odontoblastic differentiation of hPDLSCs. These therapeutic properties of ATN can serve as a theoretical basis for further research on the applicability of ATN in periodontal tissue regeneration.

6

Cite

Share

Evaluation of component release and oxygen-inhibited layer removal on cytotoxicity of syringe-type bis-acryl composites for provisional restorations

En-Shi JIANG ; Yukyung CHOI ; Bum-Soon LIM ; Young-Seok PARK ; Shin Hye CHUNG

Korean Journal of Dental Materials.2022;49(4):173-186. doi:10.14815/kjdm.2022.49.4.173

This study aimed to analyze the eluted components of syringe-type bis-acryl composites and to evaluate the effect of removing the oxygen-inhibited layer on cytotoxicity. Four different bis-acryl provisional composite materials-Protemp 4 (PT), Structur 2 SC (ST), Luxatemp Automix Plus (LT), and Hexa-Temp (HT)-were evaluated. Gas chromatography/mass spectrometry was used to analyze the composite eluate after 24 h of immersion in methanol. An agar overlay test and a live/dead assay were performed on the polymerized disc-shaped specimens after 24 h. To evaluate the effect of removing the oxygen-inhibited layer, samples were prepared with a surface oxygen-inhibited layer. The surface oxygen-inhibited layer of the disc-shaped specimens was removed with alcohol only (subgroup A) or with polishing and alcohol (subgroup PA), and their cytotoxicities were compared with those of “as received” (subgroup N) specimens using the WST-1 assay. Statistical significance was assessed using analyses of variance, followed by Bonferroni multiple comparison tests (α=0.05). Different components were detected by gas chromatography/mass spectrometry analysis among the groups. The agar overlay assay confirmed severe cytotoxicity in HT, LT, and ST groups, whereas PT showed moderate cytotoxicity. The effect of removing the oxygen-inhibited layer on cell viability was significantly higher in PA than in N in all composite groups. In HT and ST, the cell viability was significantly higher in PA than in A. Syringe-type bis-acryl composites for provisional restorations may elute various components into the oral cavity, which may cause cytotoxicity in adjacent structures. The cytotoxicity of the materials is reduced by the removal of the oxygen-inhibited layer.

7

Cite

Share

Antibacterial properties of dental resin incorporated with nano-silver doped silica in accordance with exposure of visible light

Min-Yong LEE ; Hi-Won YOON ; Kwang-Mahn KIM ; Jae-Sung KWON

Korean Journal of Dental Materials.2022;49(4):161-172. doi:10.14815/kjdm.2022.49.4.161

This study investigated reduction of the bandgap of silica by applying nano-silver doping technique and possible application of such silica as a filler in dental resin. Due to reduce band gap, newly fabricated nano-silver doped silica was able to release ROS in accordance with exposure of visible light. Nano-silver doped silica was composed of below 20 nm size crystal silver nanoparticle and 100~500 nm size amorphous silica. These two components were chemically attached to each other (Si-O-Ag). The reduced bandgap was 2.10 eV, which the value could be interpreted as occurrence of surface plasmon resonance generating ROS in visible light exposure conditions. When such nano-silver doped silica was used as a filler in dental resin, increased antibacterial property of nano-silver ion was observed which was related to releasing of ROS when exposed in visible light. The antibacterial properties were statistically significant following exposure to visible light when 0.7 to 1.5 wt% of nano-silver doped silica were incorporated into resin. When the contents of nano-silver doped silica were below 0.7 wt%, minimal ROS release resulted in no significant increase in antibacterial properties as there would be less exposed nano-silver doped silica on the resin surface by visible light. Meanwhile, more than 1.5 wt% of nano-silver doped silica also resulted no significant increase in antibacterial properties following exposure to visible light as the antibacterial effects from nano-silver ion itself were greater than effects from released ROS. Hence, it was concluded that dental resin containing 0.7 to 1.5 wt% of nano-silver doped silica would provide antibacterial properties when exposed to visible light, significantly greater than in dark conditions.

8

Cite

Share

Photocatalytic effect of doped-TiO 2 nanoparticles on discolored teeth

Unchul SHIN ; Hyo-Joung SEOL ; Yong Hoon KWON

Korean Journal of Dental Materials.2022;49(4):153-160. doi:10.14815/kjdm.2022.49.4.153

The aim of this study was to determine the photocatalytic effect of doped-TiO 2 nanoparticles (NPs) on teeth bleaching with an aid of 3% H2O2 and laser irradiation. For the study, Mo-N-TiO2 NPs were prepared. The characteristics of the prepared NPs, NPs morphology and light absorbance, were evaluated. Photocatalytic reactions of NPs were tested using 10 ppm methylene blue (MB) solution. Extracted teeth were pasted using carbomer gel for color differences measurements. Mo-N-TiO2 NPs have close to round shape with some tens nm size. Their absorbance was higher and longer than that of TiO 2 NPs. For MB solution, Mo-N-TiO2 with 3% H2O2 condition showed much decrease in absorbance after laser irradiation for 20 min. Also, regardless of wavelength, Mo-N-TiO2 NPs produced much greater color difference (whitening) on teeth after 3 h than that by 15% H2O2 .

9

Cite

Share

Inhibitory effects of surface-grafted polylactide-co-glycolide nanoparticles on the pro-inflammatory polarization of macrophages

Sang Hoon CHOI ; Gyeung Mi SEON ; Quang Canh VO ; Gitae SON ; Hyeong-Cheol YANG

Korean Journal of Dental Materials.2022;49(4):141-152. doi:10.14815/kjdm.2022.49.4.141

Phosphatidylserine (PS) mimics the anti-inflammatory effect of apoptotic cells by binding to the PS receptor of macrophages. In this study, the effect of PS-modified polylactide-co-glycolide (PLGA) nanoparticles on macrophage polarization was investigated.PLGA nanoparticles (PLGAnPs) containing phosphatidylcholine (PC) and PS were prepared using the emulsificationsolvent-evaporation (ESE) technique and classified as follows: 1) PC 100% (PCnP); 2) PS:PC = 50:50 (PSPCnP); and 3) PS 100% (PSnP). PS-grafted PLGAnPs tended to inhibit LPS-induced morphological change into M1 macrophages and mRNA expression of the M1 markers (TNF-α, IL-1β, IL-6, IL-12p40, CD86, and iNOS). In particular, the expressions of TNF-α, IL-6, and IL-12p40 were significantly decreased in the PSPCnP group, as compared to those of the positive control and and PLGAnP groups (p<0.05). Therefore, the study results demonstrate the potential of PS-grafted PLGAnPs in attenuating inflammation and modulating the drug delivery system.

10

Cite

Share

Real-time analysis of temperature change in composite photopolymerization using non-contact infrared sensor

Chang-Ha LEE ; In-Bog LEE

Korean Journal of Dental Materials.2022;49(4):131-140. doi:10.14815/kjdm.2022.49.4.131

The aim of this study was to investigate the effects of the radiant emittance of an LED light on temperature change during composite photopolymerization using a non-contact infrared sensor. A thermometer was prepared using a non-contact infrared sensor and a microcontroller. After preparing a disc-shaped composite specimen using a micro-hybrid conventional (Z250) or nano bulk-fill (BFP) composite, the temperature change of the prepared composite during photopolymerization was measured based on three photopolymerization protocols (Duty ratio/exposure time; 100%/20 s, 50%/40 s, and Increase (0→100%)/40 s) using a pulse width modulated (PWM) LED light. Subsequently, second light exposure, having the same protocol as the first, was performed on the photopolymerized composite. The first peak temperature rise of composite photopolymerization (ΔT total) and second peak temperature rise caused by the LED light (ΔT light ) were obtained from the temperature change vs. time curve.The net peak temperature rise caused by the curing heat of the composite (ΔT composite ) was obtained by subtracting the second curve from the first one. The peak time was defined as the time when ΔT composite occurred. ΔT total and ΔT composite of the 100%/20 s group were the highest and ΔT light of the 50%/40 s group was the lowest for both the composites (p<0.05). The temperature rise of Z250 was higher than that of BFP in all the groups except the ΔT composite of the Increase/40 s group (p<0.05). The peak time of the Increase/40 s group was the longest in both the composites, and the peak time of BFP was longer than that of Z250 in all the photopolymerization protocols (p<0.05). A real-time analysis of the temperature change during composite photopolymerization was effectively performed using the non-contact infrared sensor. Through this analysis, the polymerization kinetics of the composite could also be evaluated.

DISPLAY OPTIONS

Cite

Share

Cite

Share

Cite

Share

Cite

Share

Cite

Share

Cite

Share

Cite

Share

Cite

Share

Cite

Share

Cite

Share