1.Sustainability of the antibacterial activity of experimental fluoride varnish mixed with antibacterial agents against Streptococcus mutans
Korean Journal of Dental Materials 2020;47(2):63-70
This study aimed to assess the sustainability of antibacterial agents mixed with experimental fluoride varnish (EFV) against S. mutans. Five antibacterial agents [Xanthorrhizol (XAN), Bakuchiol (BAK), Bavachalcone (BCC), Isobavachromene (IBC), and Bavachromene (BCM)] were used and incorporated into the EFV to make the final concentration of 10 mM. Then, 5 μL of antibacterial agents mixed with EFV were applied on polyethylene terephthalate film disc (5 mm diameter). The positive and vehicle control were ampicillin and DMSO mixed with EFV, respectively. Each group was stored in distilled water in a 37℃ shaking water bath at 80 rpm for 0 hour, 4 hours, 1 day, 2 days, 3 days, 5 days, 10 days, 20 days and 30 days. The sustainability of the antibacterial activities was evaluated with the inhibition zone by the agar diffusion test. The antibacterial activities of all antibacterial agents were sustained for 30 days. Among them, BCC showed relatively higher antibacterial activities up to 30 days compared to other groups. This study suggests that antibacterial agents including BCC can be used with fluoride varnish to have sustained antibacterial activities.
2.Mechanical properties and biocompatibility of experimental 3D printing denture base resin
Korean Journal of Dental Materials 2019;46(4):253-262
This study was conducted to compare the flexural properties and biocompatibility of experimental 3D printing resins with commercial 3D-printing resins and conventional denture base resin. Auto polymerized pour-type denture base resin (RESS LT; Retec, Germany) was used as a control group. A commercial 3D printing denture base resin, NextDent (Base, Vertex Dental, Soesterberg, Netherlands) and two 3D printing resins, White prototyping resin (PR57-W, Autodesk, USA) and Clear prototyping resin (PR48, Autodes, usa) were compared. Experimental 3D printing resins (E1, E2, E3) were made with different ratios of dimethacrylates. DLP 3D printer (VIDA, Envisiontec) was used for 3D printing. The specimens (64×10×3.3 mm) were made based on the protocol of ISO 20795-1. The flexural strength and flexural modulus were measured by a universal testing machine (Z020, Zwick, Germany) at a crosshead speed of 5 mm/min. MTT test was performed to evaluate the cell viability. The flexural strength and flexural modulus of E2 were significantly higher than those of other groups (p<0.05). Biocompatibility of all experimental 3D printing resins were not significantly different from negative group (p>0.05). E2 is considered to be a promising material as a denture base resin for 3D printing.
3.The Effect of Cataract Operation on Ocular Hypotony after Trabeculectomy with Mitomycin C.
Sung Chil WOO ; Ji Myung YOO ; Ji Hong BAE
Journal of the Korean Ophthalmological Society 1998;39(9):2121-2128
Cataract operation was carried out in 7 glaucomatous eyes with prolonged ocular hypotony after trageculectomy with intraoperative mitomycin C. In all cases, The postoperative intraocular pressure(IOP) rose and the postopeative average IOP was 6.0+/-2.0mmHg higher than their preoperative average IOP. The preexisting bleb was reduced in size eyes that underwent phacoemulsification and posterior chamber intraocular lens(PC-IOL) implantation. But. It was not changed in extracapsular cataract extraction and IOL implantation. In our study, cataract operation in eyes that had lens opacity with prolonged hypotony induced IOP rise and was beneficial to hypotony.
Blister
;
Cataract Extraction
;
Cataract*
;
Mitomycin*
;
Ocular Hypotension*
;
Phacoemulsification
;
Trabeculectomy*
4.Multiple Brachymetacarpia Treated by Distraction Osteogenesis.
In Tak BAE ; Ji Kang PARK ; Seung Myung CHOI ; Gook Jong KIM
Journal of the Korean Society for Surgery of the Hand 2017;22(2):122-126
The treatment of a brachymetacarpia using a distraction osteogenesis was mostly single, unilateral pattern. In case of multiple brachymetacarpia, single-stage lengthening or rapid distraction lengthening with a bone graft were usually used. Multiple brachymetacarpia treated by distraction osteogenesis is rarely reported. We report a case of a 15-year-old female presented with bilateral multiple brachymetacarpia treated by distraction osteogenesis simultaneously without complications. Also, we have evaluated the clinical results and factors which influence the clinical results.
Adolescent
;
Brachydactyly
;
Female
;
Hand Deformities
;
Humans
;
Osteogenesis, Distraction*
;
Transplants
5.Molecular Diagnosis of Cutaneous T Cell Lymphoproliferative Diseases.
Ji Young PARK ; Myung Hoon LEE ; Eun Kyung KWAK ; Dong Ja KIM ; Tae In PARK ; Han Ik BAE
Korean Journal of Pathology 2000;34(11):941-949
It is often problematic to diagnose T-cell lymphoproliferative disorders of the skin because of the difficulty in establishing clonality in paraffin-embedded tissue. We used polymerase chain reaction single strand conformational polymorphism (PCR-SSCP) and heteroduplex analysis in paraffin embedded tissue to detect clonal rearrangement of T-cell receptor gamma (TCRgamma) gene in 17 T-cell lymphoproliferative disorders and 6 atypical lymphoproliferative diseases. We used polymerase chain reaction to detect TCR beta gene rearrangement in 8 of 17 cases which did not show TCRgamma gene rearrangement. Jurkat cell lines were used as monoclonal controls. DNA was extracted from 5 biopsies of T-cell lymphomas, 10 biopsies of mycosis fungoides, 2 biopsies of lymphomatoid papulosis, and 6 biopsies of atypical lymphoproliferative lesions. We detected monoclonality in 5 of 5 T-cell lymphoma cases, 2 of 2 lymphomatoid papulosis cases, 6 of 10 mycosis fungoides cases, and 2 of 6 atypical lymphoproliferative disease cases. We conclude that nonradioactive PCR-SSCP for TCR gene rearrangement analysis is a useful adjunct to routine histological and immunophenotypic methods in the diagnosis of cutaneous T cell lymphoproliferative disorders in paraffin embedded tissue.
Biopsy
;
Diagnosis*
;
DNA
;
Gene Rearrangement
;
Genes, T-Cell Receptor
;
Genes, T-Cell Receptor beta
;
Heteroduplex Analysis
;
Humans
;
Jurkat Cells
;
Lymphoma, T-Cell
;
Lymphomatoid Papulosis
;
Lymphoproliferative Disorders
;
Mycosis Fungoides
;
Paraffin
;
Polymerase Chain Reaction
;
Receptors, Antigen, T-Cell
;
Skin
;
T-Lymphocytes
6.Intravascular Lymphomatosis in Central Nervous System.
Byung In HAN ; Myung Cheol BAE ; Ji Man HONG ; Kyoon HUH ; Jae Ho HAN
Journal of the Korean Neurological Association 2001;19(4):413-416
Intravascular lymphomatosis (IL) is a variant of non-Hodgkin's lymphoma with an predilection for the CNS. Most cases are not diagnosed until postmortem. IL is characterized by neoplastic proliferation of lymphoid cells within the lumen of small veins and arteries with minimal involvement of the parenchyma. We experienced a 62-year-old woman who presented with seizure and fever associated with anemia, elevated LDH and beta 2-microglobulin without systemic involvement. This report illustrates the diagnostic challenge of this rare disorder with a grave prognosis. (J Korean Neurol Assoc 19(4):413~416, 2001)
Anemia
;
Arteries
;
beta 2-Microglobulin
;
Central Nervous System*
;
Female
;
Fever
;
Humans
;
L-Lactate Dehydrogenase
;
Lymphocytes
;
Lymphoma, Non-Hodgkin
;
Middle Aged
;
Prognosis
;
Seizures
;
Veins
7.Remineralization effect of experimental fluoride varnish with nano-sized hydroxyapatite and tricalcium phosphate
Seong-jin SHIN ; Ju-Lee SON ; Seunghan OH ; Ji-Myung BAE
Korean Journal of Dental Materials 2020;47(3):131-142
The purpose of this study was to evaluate the remineralization effect of experimental fluoride varnish mixed with nano-tricalcium phosphate (TCP) and nano-hydroxyapatite (HA) on bovine teeth under demineralization and remineralization cycling by Vickers hardness. After fabrication of rosin-based experimental fluoride varnish with 5 wt% of NaF (EX) in the laboratory, 10 wt% of nano-hydroxyapatite (HA+EX) and nano-TCP (TC+EX) were mixed, respectively. Casein phosphopeptide-amorphous calcium phosphate (Tooth mousse) (CP) was used for comparison. Bovine incisors were impregnated by acrylic resin and exposed to caries inducing solution for 72 hours. EX, HA+EX, TC+EX, and CP were applied on the surface of bovine teeth. The specimens were immersed in a demineralization solution for 1 hour and in a re-mineralization solution for 23 hours and the cycle was repeated for 20 days. Vickers hardness was measured at baseline and after each treatment. CP group showed the highest hardness value at 24 hours after application of each material (p<0.05) and the other groups were not significantly different (p>0.05).On the 10th day of de-/re-mineralization cycling, the TC+EX group showed the highest hardness value (p<0.05), but not significantly different from the HA+EX group (p>0.05). On the 20th day, the TC+EX group kept the highest hardness value, followed by HA+EX and EX groups (p<0.05). In conclusion, experimental fluoride varnish with 10 wt% of nano-TCP showed higher remineralization effect on the enamel of bovine teeth during the de/re-mineralization cycling.
8.Remineralization effect of experimental fluoride varnish with nano-sized hydroxyapatite and tricalcium phosphate
Seong-jin SHIN ; Ju-Lee SON ; Seunghan OH ; Ji-Myung BAE
Korean Journal of Dental Materials 2020;47(3):131-142
The purpose of this study was to evaluate the remineralization effect of experimental fluoride varnish mixed with nano-tricalcium phosphate (TCP) and nano-hydroxyapatite (HA) on bovine teeth under demineralization and remineralization cycling by Vickers hardness. After fabrication of rosin-based experimental fluoride varnish with 5 wt% of NaF (EX) in the laboratory, 10 wt% of nano-hydroxyapatite (HA+EX) and nano-TCP (TC+EX) were mixed, respectively. Casein phosphopeptide-amorphous calcium phosphate (Tooth mousse) (CP) was used for comparison. Bovine incisors were impregnated by acrylic resin and exposed to caries inducing solution for 72 hours. EX, HA+EX, TC+EX, and CP were applied on the surface of bovine teeth. The specimens were immersed in a demineralization solution for 1 hour and in a re-mineralization solution for 23 hours and the cycle was repeated for 20 days. Vickers hardness was measured at baseline and after each treatment. CP group showed the highest hardness value at 24 hours after application of each material (p<0.05) and the other groups were not significantly different (p>0.05).On the 10th day of de-/re-mineralization cycling, the TC+EX group showed the highest hardness value (p<0.05), but not significantly different from the HA+EX group (p>0.05). On the 20th day, the TC+EX group kept the highest hardness value, followed by HA+EX and EX groups (p<0.05). In conclusion, experimental fluoride varnish with 10 wt% of nano-TCP showed higher remineralization effect on the enamel of bovine teeth during the de/re-mineralization cycling.
9.Setting time of root canal sealers and root-end filling materials by different measuring methods
Gyu-Yeon SHIM ; Seong-jin SHIN ; Seunghan OH ; Ji-Myung BAE
Korean Journal of Dental Materials 2023;50(3):169-178
The aim of this study was to evaluate the differences in setting times based on the methods for dental root canal sealers and calcium silicate cement used in root-end filling. Five kinds of dental root canal sealers and four kinds of calcium silicate cement for root-end filling were selected for the experiments. All materials were mixed according to the manufacturers’ instructions and stored at 37 ℃ with a relative humidity of 95%. Setting time was measured using a 1/4 pound Gillmore needle and a 1 pound Gillmore needle to determine the time until indentation was no longer visible or the time until 2 mm penetration was no longer possible. The determination of indentation was based on the absence of visible impressions on the material surface when Gillmore needle was placed vertically. When comparing indentation time and penetration time using same type of Gillmore needle, only ProRoot MTA using 1 pound Gillmore needle showed significant difference between measuring methods (P<0.05) while there are no differences in measuring methods in other materials (P>0.05). By this study, we could expect to measure a setting time relatively similar to real clinical conditions through indentation method.
10.Evaluation of machining accuracy of zirconia Merlon fracture test models fabricated by subtractive and additive manufacturing
Heejung LEE ; Ji-Myung BAE ; Seunghan OH
Korean Journal of Dental Materials 2024;51(1):53-62
The machining accuracy of zirconia prostheses fabricated by the subtractive (SM) and additive manufacturing (AM) was evaluated using the Merlon fracture test model in ISO 18675 (2022). The SM specimens were fabricated by a DWX-51D (Roland, Sydney, NSW, Australia) using two zirconia blocks (Katana Zirconia HT; KH, Katana Zirconia STML; KS). The AM specimens were prepared by a DLP type 3D printer INNI-Ⅱ (AON, Gunpo, Korea) using zirconia liquid slurry (INNI-CERA; PZ). The specimen STL image was acquired using a model scanner (E3, 3 Shape A/S, Copenhagen, Denmark). The machining accuracy of the specimens was analyzed by the RMS method superimposing the reference STL image and the specimen STL image in image analysis software (Geomagic Control X, 3D Systems, Rock Hill, SC, USA). From the results of the machining accuracy analysis, the KH and KS groups showed statistically significantly better machining accuracy (lower RMS) than the PZ group (P<0.05). The KH and KS groups showed higher machining accuracy as the thickness decreased, and the 0.2 mm and 0.3 mm experimental groups showed statistically significantly better machining accuracy than the 0.4 mm experimental group (P<0.05). On the other hand, the PZ group showed better machining accuracy as the thickness increased, with the 0.4 mm group showing statistically significantly better machining accuracy than the 0.2 mm and 0.3 mm groups (P<0.05). Within the limitation of this study, the thickness of the final zirconia prosthesis fabricated by additive manufacturing should be at least 0.4 mm for clinical use in dentistry.