1.Diastema closure with direct composite: architectural gingival contouring.
Journal of Korean Academy of Conservative Dentistry 2011;36(6):515-520
One of the most challenging task in closing anterior diastema is avoiding "black triangle" between the teeth. This paper reports a case that the closure of diastema in anterior teeth could be successfully accomplished using direct adhesive restorations and gingival recontouring. The traditional technique using Mylar strip was modified to increase the emergence profile with natural contours at the gingival-tooth interface. Mylar strip was extended out of the sulcus by approximately 1 mm high from the gingival margin, and a small cotton pellet was used to provide the emergence contour. This modified approach is acceptable for the clinical situation.
Adhesives
;
Diastema
;
Polyethylene Terephthalates
;
Tooth
2.Failure of orthograde MTA filling: MTA wash-out?.
Yuran KIM ; Chan Young LEE ; Euiseoung KIM ; Il Young JUNG
Journal of Korean Academy of Conservative Dentistry 2011;36(6):510-514
Mineral trioxide aggregate (MTA), which was originally developed for repair of root perforations, is a biocompatible material with numerous clinical applications in endodontics. MTA must be allowed to set in the presence of moisture to optimize the material's physical and chemical properties. In the clinic, occasionally unset MTA has been detected after application of MTA on the tooth, and the reason has been unclear. This case report presents MTA washed-out for several years after placement at the root apex as an apical plug, and discusses the reason and things to consider in clinics.
Aluminum Compounds
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Calcium Compounds
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Drug Combinations
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Endodontics
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Glutamates
;
Guanine
;
Oxides
;
Silicates
;
Tooth
;
Pemetrexed
3.Subcutaneous emphysema during fracture line inspection: case report.
Min Young KIM ; Sung Ho PARK ; Yoo Seok SHIN ; Euiseong KIM
Journal of Korean Academy of Conservative Dentistry 2011;36(6):506-509
The development of subcutaneous emphysema is a well-known complication that has been reported after dental extraction, endodontic treatment, or restorative preparation. Gaseous invasion, leading to swelling, crepitus on palpation, is commonly restricted to the connective tisssues immediately adjacent to the entry site. However, the use of compressed air- and water-cooled turbines may allow large amounts of air and water to be driven through the fascial planes into the mediastinum, pleural space, or even the retroperitoneum. This case report is about the patient who presented with subcutaneous emphysema that occurred after fracture line inspection. Possible cause, treatment, and prevention of emphysema will be discussed.
Emphysema
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Humans
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Mediastinum
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Palpation
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Subcutaneous Emphysema
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Water
4.Microbial profile of asymptomatic and symptomatic teeth with primary endodontic infections by pyrosequencing.
Sang Min LIM ; Tae Kwon LEE ; Eun Jeong KIM ; Jun Hong PARK ; Yoon LEE ; Kwang Shik BAE ; Kee Yeon KUM
Journal of Korean Academy of Conservative Dentistry 2011;36(6):498-505
OBJECTIVES: The purpose of this in vivo study was to investigate the microbial diversity in symptomatic and asymptomatic canals with primary endodontic infections by using GS FLX Titanium pyrosequencing. MATERIALS AND METHODS: Sequencing was performed on 6 teeth (symptomatic, n = 3; asymptomatic, n = 3) with primary endodontic infections. Amplicons from hypervariable region of the small-subunit ribosomal RNA gene were generated by polymerized chain reaction (PCR), and sequenced by means of the GS FLX Titanium pyrosequencing. RESULTS: On average, 10,639 and 45,455 16S rRNA sequences for asymptomatic and symptomatic teeth were obtained, respectively. Based on Ribosomal Database Project Classifier analysis, pyrosequencing identified the 141 bacterial genera in 13 phyla. The vast majority of sequences belonged to one of the seven phyla: Actinobacteria, Bacteroidetes, Firmicutes, Fusobacteria, Proteobacteria, Spirochetes, and Synergistetes. In genus level, Pyramidobacter, Streptococcus, and Leptotrichia constituted about 50% of microbial profile in asymptomatic teeth, whereas Neisseria, Propionibacterium, and Tessaracoccus were frequently found in symptomatic teeth (69%). Grouping the sequences in operational taxonomic units (3%) yielded 450 and 1,997 species level phylotypes in asymptomatic and symptomatic teeth, respectively. The total bacteria counts were significantly higher in symptomatic teeth than that of asymptomatic teeth (p < 0.05). CONCLUSIONS: GS FLX Titanium pyrosequencing could reveal a previously unidentified high bacterial diversity in primary endodontic infections.
Actinobacteria
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Bacteria
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Bacteroidetes
;
Fusobacteria
;
Genes, rRNA
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Leptotrichia
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Neisseria
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Polymers
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Propionibacterium
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Proteobacteria
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Spirochaetales
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Streptococcus
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Titanium
;
Tooth
5.Bonding efficacy of cured or uncured dentin adhesives in indirect resin.
Ji Hyun JANG ; Bin Na LEE ; Hoon Sang CHANG ; Yun Chan HWANG ; Won Mann OH ; In Nam HWANG
Journal of Korean Academy of Conservative Dentistry 2011;36(6):490-497
OBJECTIVES: This study examined the effect of the uncured dentin adhesives on the bond interface between the resin inlay and dentin. MATERIALS AND METHODS: Dentin surface was exposed in 24 extracted human molars and the teeth were assigned to indirect and direct resin restoration group. For indirect resin groups, exposed dentin surfaces were temporized with provisional resin. The provisional restoration was removed after 1 wk and the teeth were divided further into 4 groups which used dentin adhesives (OptiBond FL, Kerr; One-Step, Bisco) with or without light-curing, respectively (Group OB-C, OB-NC, OS-C and OS-NC). Pre-fabricated resin blocks were cemented on the entire surfaces with resin cement. For the direct resin restoration groups, the dentin surfaces were treated with dentin adhesives (Group OB-D and OS-D), followed by restoring composite resin. After 24 hr, the teeth were assigned to microtensile bond strength (microTBS) and confocal laser scanning microscopy (CLSM), respectively. RESULTS: The indirect resin restoration groups showed a lower microTBS than the direct resin restoration groups. The microTBS values of the light cured dentin adhesive groups were higher than those of the uncured dentin adhesive groups (p < 0.05). CLSM analysis of the light cured dentin adhesive groups revealed definite and homogenous hybrid layers. However, the uncured dentin adhesive groups showed uncertain or even no hybrid layer. CONCLUSIONS: Light-curing of the dentin adhesive prior to the application of the cementing material in luting a resin inlay to dentin resulted in definite, homogenous hybrid layer formation, which may improve the bond strength.
Adhesives
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Chimera
;
Dentin
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Humans
;
Inlays
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Light
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Microscopy, Confocal
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Molar
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Resin Cements
;
Tooth
6.Effect of glycerin on the surface hardness of composites after curing.
Journal of Korean Academy of Conservative Dentistry 2011;36(6):483-489
OBJECTIVES: The purpose of this study was to examine the effect of glycerin topical application on the surface hardness of composite after curing. MATERIALS AND METHODS: A composite (Z-250, 3M ESPE) was packed into a disc-shaped brass mold and light cured according to one of the following protocols. Group 1 (control) was exposed to air and light cured for 40 sec, group 2 was covered with a Mylar strip and light cured for 40 sec, group 3 was surface coated with glycerin and light cured for 40 sec, and group 4 was exposed to air and light cured for 20 sec and then surface coated with glycerin and cured for additional 20 sec. Twenty specimens were prepared for each group. The surface hardnesses of specimens were measured with or without polishing. Five days later, the surface hardness of each specimen was measured again. Data were analyzed by three-way ANOVA and Tukey's post hoc tests. RESULTS: The surface hardnesses of the unpolished specimens immediately after curing decreased in the following order: group 2 > 3 > 4 > 1. For the polished specimens, there was no significant difference among the groups. Within the same group, the hardness measured after five days was increased compared to that immediately after curing, and the polished specimens showed greater hardness than did the unpolished specimens. CONCLUSIONS: The most effective way to increase the surface hardness of composite is polishing after curing. The uses of a Mylar strip or glycerin topical application before curing is recommended.
Copper
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Fungi
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Glycerol
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Hardness
;
Light
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Polyethylene Terephthalates
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Zinc
7.Microshear bond strength of a self-etching primer adhesive to enamel according to the type of bur.
Jin Ho JEONG ; Young Gon CHO ; Myung Seon LEE
Journal of Korean Academy of Conservative Dentistry 2011;36(6):477-482
OBJECTIVES: The purpose of this study was to compare the microshear bond strength (uSBS) to enamel prepared with different burs and to determine what type of bur were chosen when a self-etching primer adhesive was used. MATERIALS AND METHODS: Enamel of forty-two human molars were used. They were divided into one of six groups (n = 7), Group 1, coarse (125 - 150 microm) diamond bur; Group 2, standard (106 - 125 microm) diamond bur; Group 3, fine (53 - 63 microm) diamond bur; Group 4, extrafine (20 - 30 microm) diamond bur; Group 5, plain-cut carbide bur (no. 245); Group 6, cross-cut carbide bur (no. 557). Clearfil SE Bond and Clearfil AP-X (Kuraray Medical Inc.) was bonded to enamel surface. The bonded specimens were subjected to uSBS testing. RESULTS: The uSBS of Group 4 was the highest among groups and it was significantly higher than that of Groups 1, 2, 3, and 6 (p < 0.05), but it was not significantly different from that of Group 5. CONCLUSIONS: Different burs used on enamel surface affected the microshear bond strengths of a self-etching primer adhesive to the enamel surface. In the case of Clearfil SE Bond, extrafine diamond and plain-cut carbide bur are recommended for bonding to enamel.
Adhesives
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Dental Enamel
;
Diamond
;
Humans
;
Methacrylates
;
Molar
;
Resin Cements
8.Success and failure of endodontic microsurgery.
Journal of Korean Academy of Conservative Dentistry 2011;36(6):465-476
In current endodontic practice, introduction of operating microscope, ultrasonic instruments, and microinstruments has induced a big change in the field of surgical retreatment. In this study, we aimed to offer key steps of endodontic microsurgery procedure compared with traditional root-end surgery, and to evaluate factors influencing success and failure based on published articles. Endodontic microsurgery is a surgical procedure performed with the aid of a microscope, ultrasonic instruments and modern microsurgical instruments. The microscope provides magnification and illumination - essential for identifying minute details of the apical anatomy. Ultrasonic instruments facilitate the precise root-end preparation that is within the anatomical space of the canal. Modern endodontics can therefore be performed with precision and predictability, thus eliminating the disadvantages inherent in traditional periapical surgery such as large osteotomy, beveled apicoectomy, inaccurate root-end preparation and the inability to observe isthmus. Factors influencing the outcomes of endodontic microsurgery may be diverse, but standardization of procedures can minimize its range. Among patient and tooth-related factors, periodontal status and tooth position are known to be prognostic, but there are only few articles concerning this matter. High-evidence randomized clinical trials or prospective cohort studies are needed to confirm these findings.
Apicoectomy
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Cohort Studies
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Endodontics
;
Humans
;
Lighting
;
Microsurgery
;
Osteotomy
;
Retreatment
;
Tooth
;
Ultrasonics
9.The evaluation of color and color difference according to the layering placement of Incisal shade composites on the body composites of the indirect resin restoration.
Su Jung PARK ; Han Young LEE ; Myong Yun NAH ; Hoon Sang CHANG ; Yun Chan HWANG ; Won Mann OH ; In Nam HWANG
Journal of Korean Academy of Conservative Dentistry 2011;36(1):37-49
OBJECTIVES: The aim of this study was to evaluate the surface color of indirect resin restoration according to the layering placement of different shade of incisal composite. MATERIALS AND METHODS: In this study, CIE L*a*b* value of 16 Body composite of Tescera ATL (Bisco, Schaumburg IL,USA) was measured by spectrophotometer (NF999, Nippon Denshuku, Japan), and compared to CIE L*a*b* value of Vitapan shade guide. Nine shade Incisal composite of Tescera ATL were build-up to 1 mm thickness on Body composites inlay block, and CIE L*a*b* value was measured. Incisal composite was ground to 0.5 mm thickness and CIE L*a*b* value was re-measured. Color difference between Body composite and Incisal composites layered on Body composite was calculated as a function of thickness. RESULTS: Color difference between corresponding shade of Tescera Body composite and Vitapan shade guide was from 6.88 to 12.80. L* and b*value was decreased as layering thickness of Incisal composite on Body composite was increased. But, a* value did not show specific change tendency. CONCLUSIONS: Surface color difference between Body composites and Incisal composites layered on Body composite was increased as the layering thickness of Incisal composite increased (p < 0.05).
Composite Resins
;
Inlays
10.The effect of tumor necrosis factor (TNF)-alpha to induce matrix metalloproteinase (MMPs) from the human dental pulp, gingival, and periodontal ligament cells.
Eun Mi RHIM ; Sang Hyuk PARK ; Duck Su KIM ; Sun Young KIM ; Kyoung Kyu CHOI ; Gi Woon CHOI
Journal of Korean Academy of Conservative Dentistry 2011;36(1):26-36
OBJECTIVES: In the present study, three kinds of tissues cells (pulp, gingiva, and periodontal ligament) were investigated if those cells express MMP and TIMP when they were stimulated with neuropeptides (substance P, CGRP) or proinflammatory cytokine, TNF-alpha. MATERIALS AND METHODS: The cells cultured from human dental pulp (PF), gingiva (GF) and periodontal ligament were (PDLF) stimulated with Mock, SP, TNF-alpha, and CGRP for 24 hrs and 48 hrs. for an RNase protection assay and Enzyme Linked Immunosorbent Assay. Cells (PF, GF and PDLF) seeded in 100 mm culture dish were stimulated with SP (10(-5), 10(-8) M) or only with medium (Mock stimulation) for 4hrs and for 24 hrs for RNase Protection Assay, and they were stimulated with CGRP (10(-5) M) and TNF-alpha (2 ng/mL) for 24 hrs and with various concentraion of TNF-alpha (2, 10, and 100 ng/mL) for Rnase Protection Assay with a human MMP-1 probe set including MMP 1, 2, 8, 7, 8, 9, 12, and TIMP 2, 3. In addition, cells (PF, GF and PDLF) were stimulated with Mock and various concentraion of TNF-alpha(2, 10, and 100 ng/mL) for 24 hrs and with TNF-alpha(10 ng/mL) for 48 hrs, and the supernatents from the cells were collected for Enzyme Linked Immunosorbent Assay (ELISA) for MMP-1 and MMP-13. RESULTS: The expression of MMPs in PF, GF, PDLF after stimulation with SP and CGRP were not changed compared with Mock stimulation for 4 hrs and 24 hrs. The expression of MMP-1, -12, -13 24 hrs after stimulation with TNF-alpha were upregulated, however the expression of TIMP-3 in PF, GF, PDLF after stimulation with TNF-alpha were downregulated. TNF-alpha (2 ng/mL, 10 ng/mL, 100 ng/mL) increased MMP-1 and MMP-12 expression in PF dose dependently for 24 hrs. CONCLUSIONS: TNF-alpha in the area of inflammation may play an important role in regulating the remodeling of dentin, cementum, and alveolar bone.
Dental Cementum
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Dental Pulp
;
Dentin
;
Enzyme-Linked Immunosorbent Assay
;
Gingiva
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Humans
;
Inflammation
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Matrix Metalloproteinases
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Neuropeptides
;
Periodontal Ligament
;
Ribonucleases
;
Seeds
;
Substance P
;
Tissue Inhibitor of Metalloproteinase-3
;
Tumor Necrosis Factor-alpha

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