1.Interdisciplinary approach on oral rehabilitation of an adolescent patient with multiple missing teeth: a clinical report.
Kung Rock KWON ; Janghyun PAEK ; Hyun Woo KIM
The Journal of Korean Academy of Prosthodontics 2013;51(4):339-346
In case of missing of permanent teeth by trauma or innate defect, the decision of treatment modalities and application timing have an important effect on the prognosis of oral rehabilitation. In this case report, interdisciplinary approach between the orthodontic and prosthodontic treatment, the way to re-establish the collapsed occlusal vertical dimension, and implant prosthetic considerations will be discussed. Proper diagnosis on teeth and craniofacial skeleton was made prior to treatment and provisional restorations were used in regard of growth patterns of the patient. Finally, the edentulous areas were restored with fixed implant prostheses. Diagnosis, treatment rationale and prognosis will be discussed thoroughly.
Adolescent*
;
Growth and Development
;
Humans
;
Prognosis
;
Prostheses and Implants
;
Prosthodontics
;
Tooth*
;
Vertical Dimension
2.A study of Ni-resistant bacteria isolated from gingival crevicular fluid on the patients wearing Ni-Cr alloy prosthesis (In terms of molecular biological aspects).
Young Ah CHAE ; Yi Hyung WOO ; Kung Rock KWON
The Journal of Korean Academy of Prosthodontics 2003;41(2):207-222
As a material of metal-ceramic prosthesis, nickel as a form of Ni-Cr alloy has been used for many dental prostheses in many cases. However, several problems in use of the alloy have been revealed (ex ; tissue stimulation, skin allergy, hypersensitivity, cytotoxicity and carcinogenecity). Little is known about nickel with respect to the relationship between Ni-prosthesis and gaining of Niresistance in oral microorganisms. The present study was undertaken to check whether use of Ni-prosthesis leads to occurrence of Ni-resistant microorganisms. So this study may suggest the possible relationships between the oral microorganisms and nickel-resistance in oral environment. Bacteria were isolated from the gingival crevicular fluid on the patients wearing Ni-Cr prosthesis. The isolated bacteria were tested for their Ni-resistance in nickel containing media at different concentration from 3mM to 110mM. E. coli HB101 was used as control. The Ni-resistant bacteria were isolated and biochemically identified. The Ni-resistant bacteria were tested several biochemical, molecular-biological tests. Performed tests were; measuring the growth curve, antibiotic test, growth ability test in liquid media, isolation of the chromosome and plasmid, digestion of DNA by restriction enzyme, electrophoresis of chromosome and plasmid DNA, identification of Ni-resistant genes by the DNA hybridization. The results were as follows: 1) The bacteria isolated from gingival crevicular fluid on the patients wearing Ni-Cr alloy prosthesis showed nickel-resistance. 2) The isolated microorganisms grew at nickel containing media of high concentrations (60mM-110mM). 3) Based on the biochemical tests, the isolated microorganisms were identified as E nterococcus faecalis(13 cases), Klebsiella pneumoniae(1 case) and Enterobacter gergoviae(1 case). 4) Enterococcus faecalis expressed not only nickel resistance but also the multi-drug resistance to several antibiotics; chloramphenicol, kanamicin, streptomycin, lincomycin, clindamycin. However, all strain showed the sensitivity against the tetracycline. 5) DNA hybridization result suggests that there is no homology between the previously known gene of nickel resistance in Klebsiella pneumoniae and chromosomal DNA of Enterococcus faecalis.
Alloys*
;
Anti-Bacterial Agents
;
Bacteria*
;
Chloramphenicol
;
Clindamycin
;
Dental Prosthesis
;
Digestion
;
DNA
;
Drug Resistance, Multiple
;
Electrophoresis
;
Enterobacter
;
Enterococcus faecalis
;
Gingival Crevicular Fluid*
;
Humans
;
Hypersensitivity
;
Klebsiella
;
Klebsiella pneumoniae
;
Lincomycin
;
Nickel
;
Plasmids
;
Prostheses and Implants*
;
Skin
;
Streptomycin
;
Tetracycline
3.Spectrophotometric analysis of the influence to shade of zirconia core on the color of ceramic.
Kihyun BAEK ; Yi Hyung WOO ; Kung Rock KWON ; Hyeong Seob KIM
The Journal of Korean Academy of Prosthodontics 2008;46(4):409-419
STATEMENT OF PROBLEM: At all times people have tried to fabricate tooth restorations using tooth colored materials. Recently, demands for esthetics, even in restorations requiring strength, has brought a revolution to dentistry and increased use of zirconia. The basic color of zirconia is white to ivory. The color can be partially adapted by veneering it with ceramic materials. However, it would be better if the substructure could already be adapted to the basic color shade of neighboring teeth. By adaptation to the basic shade, it can help to reduce the necessary layer thickness of the veneer ceramic to achieve the desired color. PURPOSE: The purpose of this study was to spectrophotometrically evaluate the influence of shading of zirconia core on the final shade of all-ceramic restorations using the CIE L*a*b* system. MATERIAL AND METHODS: Core specimens (n = 20 per group) of Lava Frame Zirconia, KaVo Everest Zirconia, Digident CAD/CAM Zirconia were fabricated at 20 mm in diameter and 0.5 mm in thickness. Halves of each groups were shaded in A3 color. These core specimens were veneered with A3 porcelain of the recommended manufacturer at thickness of 0.5 mm. CIE L*a*b* coordinates were recorded for each specimen with a spectrophotometer (Model CM-2600d, Minolta, Japan) at 0.5 mm, 0.4 mm, 0.3 mm in thickness. Color differences were calculated using the equation deltaE* = [(deltaL*)2+(deltaa*)2+(deltab*)2]1/2. RESULTS: 1. In the case where porcelain layer has a thickness of 0.5 mm, Lava Frame Zirconia and KaVo Everest group did not show clinically perceived color difference, however Digident CAD/CAM Zirconia group showed clinically perceived color difference according to shade allowed on core. 2. When the thickness of porcelain layer decreased from 0.5 mm to 0.4 mm, Lava Frame Zirconia and KaVo Everest group did not show clinically perceived color difference, on the other hand Digident CAD/CAM Zirconia group showed clinically perceived color difference according to shade allowed on core. 3. When the thickness of porcelain layer decreased from 0.5 mm to 0.3 mm, clinically perceived color differences were observed from all three groups. CONCLUSIONS: Ziroconia system, which is possible to allow shade on core, are thought to be much more favorable to reproduce natural shade compared to systems that is impossible to give shade. Therefore, clinicians ought to choose adequate system for certain clinical situation by considering above specific character.
Ceramics
;
Dental Porcelain
;
Dentistry
;
Esthetics
;
Hand
;
Humans
;
Tooth
;
Zirconium
4.A Study on the Stress Distribution of Tooth/Implant Connected with Konus Telescope Denture Using 3-Dimensional Finite Element Method.
Su Ok LEE ; Dae Gyun CHOI ; Kung Rock KWON ; Yi Hyung WOO
The Journal of Korean Academy of Prosthodontics 2008;46(4):381-395
PURPOSE: For decades dental implants have been used widely in the field of prosthetic dentistry. However there is confusion when establishing treatment plans in cases where some teeth are remained but an insufficient number of implants can be used due to limited anatomical status and ecomomical problems. Many clinicians have tried to connect natural teeth and implants, and it still has controversy. But, there have been few studies on mechanical analysis of connecting natural teeth and implants with konus telescopic removable partial dentures. The purpose of this study was to analyze the stress distribution of prosthesis, abutment and alveolar bone when teeth and implants were connected with the konus telescopic denture, by means of 3-dimensional finite element analysis. MATERIAL AND METHODS: The assumption of this study was that there were 2 mandibular canine (11 mm in length, 4 mm in diameter) and 2 implants(10 mm in length, 4 mm in diameter) which are located in the second premolar region. The mandible, teeth, implants, abutments, and connectors are modeled, and analyzed with the commercial software, ANSYS Version 8.1(Swanson, Inc., USA). The control group used implants instead of natural teeth. 21038 elements, 23544 nodes were used in experimental group and 107595 elements, 21963 nodes were used in control group, Stress distribution was evaluated under 150 N vertical load on 3 experimental conditions - between teeth and implants (Load case 1), posterior to implants (Load case 2), between natural teeth (Load case 3). RESULTS: 1. In all load cases, higher von mises stress value was observed in the experimental group. 2. Maximum von miss stress observed in all load cases and all locations were as follows ; a. 929.44 Mpa in the experimental group, 640.044 Mpa in the control group in outer crown and connector - The experimental group showed 1.45 times high value compared with the control group. b. 145,051 Mpa in the experimental group, 142.338 Mpa in the control group in abutment - The experimental group showed 1.02times high value compared with the control group. c. 32.489 Mpa in the experimental group, 25.765 Mpa in the control group in alveolar bone - The experimental group showed 1.26times higher value compared with the control group. 3. All maximum von mises stress was observed in load case 2, and maxim von mises stress in alveolar bone was 32.489 Mpa at which implant failure cannot occur. 4. If maximum von mises stress is compared between two groups, the value of the experimental group is 1.02 times higher than the control group in abutment, 1.26 times higher than the control group in alveolar bone. CONCLUSION: If natural teeth and implants are connected with the konus telescopic denture, maximum stress will be similar in abutment, 1.26 times higher in alveolar bone than the control group. With this result, there may be possible to make to avoid konus telescopic dentures where natural teeth and implants exist together.
Bicuspid
;
Crowns
;
Dental Implants
;
Dentistry
;
Denture, Partial, Removable
;
Dentures
;
Finite Element Analysis
;
Mandible
;
Prostheses and Implants
;
Telescopes
;
Tooth
5.A Study of the shade of between maxillary and mandibular anterior teeth in the Korean.
Tae Jin KIM ; Kung Rock KWON ; Hyeong Seob KIM ; Yi Hyung WOO
The Journal of Korean Academy of Prosthodontics 2008;46(4):343-350
PURPOSE: The purpose of this study was to spectrophotometrically evaluate the shade difference between of maxillary and mandibular anterior teeth in the Korean by the standard of vita classical shade guide using SpectroShade(TM). MATERIAL AND METHODS: In this study, the shades of healthy anterior teeth were examined and analyzed using the digital shade analysis of SpectroShade(TM). This study examined 80 individuals in their twenties, thirties, fourties, fifities ages and 40 males and 40 females, presenting 12 healthy, unrestored maxillary and mandibular anterior teeth. Tooth brushing and oral prophylaxis were performed prior to evaluation. The SpectoShadeTM was used to acquire images of the 12 maxillary and mandibular anterior teeth. These images were analyzed using SpectroShade(TM) Software, and shade maps of each tooth were acquired. The shade difference of upper and lower, and gender differences and ages difference were investigated and analyzed with CIE L*a*b* color order system. One-Way ANOVA test was used to find out if there were significant differences between groups tested and Sheffe multiple comparison was used to identify where the differences were. RESULTS: 1. Shade differences were significant (P < .05) between maxillary and mandibular central incisor, lateral incisor, canine. 2. No significant differences in shade distribution were seen between lateral incisors and central incisors. 3. Canine's shade difference were more significant than central incisor's and lateral incisors's. 4. No significant differences in shade distribution were seen between genders in maxillary and mandibulr central incisor, lateral incisor, canine. 5. No significant differences in shade distribution were seen in order of years in maxillary and mandibulr central incisor, lateral incisor, canine. CONCLUSIONS: The results of this study show that 1. Shade difference was founded in maxillary and mandibular anterior teeth and deltaE* value was more than 2.0. 2. Canine's shade difference were more significant than central incisor's and lateral incisors's and between central incisors and lateral incisors shade differences were no significant. 3. No significant differences in shade distribution were seen between genders in maxillary and mandibular anterior teeth. 4. No significant differences in shade distribution were seen in order of years grade in maxillary and mandibular anterior teeth.
Female
;
Humans
;
Incisor
;
Male
;
Tooth
6.TENSILE BOND STRENGTH OF ALUNMINA CORE TREATED BY ION ASSISTED REACTION.
Hyeong Seob KIM ; Yi Hyung WOO ; Kung Rock KWON ; Boo Byung CHOI ; Won Kook CHOI
The Journal of Korean Academy of Prosthodontics 2000;38(5):704-723
This study was undertaken to evaluate the tensile bond strength of In-Ceram alumina core treated by ion assisted reaction(IAR). Ion assisted reaction is a prospective surface modification technique without damage by a keV low energy ion beam irradiation in reactive gas environments or reactive ion itself. 120 In-Ceram specimens were fabricated according to manufacturer's directions and divided into six groups by surface treatment methods of In-Ceram alumina core. SD group(control group): sandblasting SL group: sandblasting + silane treatment SC group: sandblasting + Siloc treatment IAR I group: sandblasting + Ion assisted reaction with argon ion and oxygen gas IAR II group: sandblasting + Ion assisted reaction with oxygen ion and oxygen gas IAR III group: sandblasting + Ion assisted reaction with oxygen ion only For measuring of tensile bond strength, pairs of specimens within a group were bonded with Panavia 21 resin cement using special device secured that the film thickness was 80micrometer. The results of tensile strength were statistically analyzed with the SPSS release version 8.0 programs. Physical change like surface roughness of In-Ceram alumina core treated by ion assisted reaction was evaluated by Contact Angle Measurement, Scanning Electron Microscopy, Atomic Force Microscopy; chemical surface change was evaluated by X-ray Photoelectron Spectroscopy. The results as follows: 1. In tensile bond strength, there were no statistically significant differences with SC group, IAR groups and SL group except control group(P<0.05). 2. Contact angle measurement showed that wettability of In-Ceram alumina core was enhanced after IAR treatment. 3. SEM and AFM showed that surface roughness of In-Ceram alumina core was not changed after IAR treatment . 4. XPS showed that IAR treatment of In-Ceram alumina core was enabled to create a new functional layer. A keV IAR treatment of In-Ceram alumina core could enhanced tensile bond strength with resin cement. In the future, this ion assisted reaction may be used effectively in various dental materials as well as in In-Ceram to promote the bond strength to natural tooth structure.
Aluminum Oxide
;
Argon
;
Dental Materials
;
Microscopy, Atomic Force
;
Microscopy, Electron, Scanning
;
Oxygen
;
Photoelectron Spectroscopy
;
Resin Cements
;
Tensile Strength
;
Tooth
;
Wettability
7.Finite element analysis of the effect of cantilever and implant orientation on stress distribution in a mandibular implant-supported bar overdenture.
Jun Soo PARK ; Sung Bok LEE ; Kung Rock KWON ; Yi Hyung WOO
The Journal of Korean Academy of Prosthodontics 2007;45(4):444-456
STATEMENT OF PROBLEM: Implant inclination and cantilever loading increse loads distributed to implants, potentially causing biomechanical complications. Controversy exists regarding the effect of the intentionally distal-inclined implant for the reduction of the cantilever length. PURPOSE: This study investigated the stress distribution at the bone/implant interface and prostheses with 3D finite element stress analysis by using four different cantilever lengths and implant inclinations in a mandibular implant-supported bar overdenture. MATERIAL AND METHODS: Four 3-D finite element models were created in which 4 implants were placed in the interforaminal area and had four different cantilver lengths(10, 6.9, 4 and 1.5mm) and distal implant inclinations(0degrees, 15degrees, 30degrees and 45degrees) respectively. Vertical forces of 120N and oblique forces of 45N were applied to the molar area. Stress distribution in the bone around the implant was analysed under different distal implant inclinations. RESULTS: Analysis of the von Mises stresses for the bone/implant interfaces and prostheses revealed that the maximum stresses occurred at the most distal bone/implant interface and the joint of bar and abutment, located on the loaded side and significantiy incresed with the implant inclinations, especially over 45degrees. CONCLUSION: Within the limitations of this study, it was suggested that too much distal inclination over 45 degrees can put the implant at risk of overload and within the dimension of the constant sum of a anterior-posterior spread and cantilever length, a distal implant inclination compared to cantilever length had the much larger effect on the stress distribution at the bone/implant interface.
Denture, Overlay*
;
Finite Element Analysis*
;
Intention
;
Joints
;
Molar
;
Prostheses and Implants
8.Prosthetic restoration of a partially edentulous patient using double crowns: a clinical report.
Minseo PARK ; Hyeong Seob KIM ; Kung Rock KWON ; Yi Hyung WOO ; Ahran PAE
The Journal of Korean Academy of Prosthodontics 2016;54(1):21-27
In removable dental prostheses, it is important to minimize impairment of residual tissue caused by wearing dentures. There are two factors that harm residual tissue. The first is functional load bearing of remaining teeth and alveolar ridges and the second is the effect of poor oral hygiene. Double crown retained removable dental prostheses provide rigid support, and it may reduce impairment caused by load bearing of alveolar ridges. Also, dental plaque and oral deposits, which are attached to outer crowns and dentures, can be easily managed extra-orally. In addition, it is beneficial to the health of the marginal gingiva because inner crowns have easy access for oral hygiene. In this case, double crown retained removable dental prostheses were used for the partially edentulous patient with severe residual alveolar bone resorption and poor oral hygiene, and the result was clinically satisfactory in terms of functional, esthetical, and oral hygiene aspects.
Bone Resorption
;
Crowns*
;
Dental Plaque
;
Dental Prosthesis
;
Dentures
;
Gingiva
;
Humans
;
Oral Hygiene
;
Tooth
;
Weight-Bearing
9.Erratum: A FEM study on stress distribution of tooth-supported and implant-supported overdentures retained by telescopic crowns.
Chang Gyu LEE ; Jang Hyun PAEK ; Tae Hun KIM ; Min Jung KIM ; Hyeong Seob KIM ; Kung Rock KWON ; Yi Hyung WOO
The Journal of Korean Academy of Prosthodontics 2012;50(3):218-218
There has been a mistake, claimed and confirmed by all the authors of Vol 50(1), 2012, p10-20 issue, that first author should have been Chang-Gyu Lee instead of Jang-Hyun Paek.
10.A Methanol Extract of Adansonia digitata L. Leaves Inhibits Pro-Inflammatory iNOS Possibly via the Inhibition of NF-kappaB Activation.
Yihunie AYELE ; Jung Ah KIM ; Eunhee PARK ; Ye Jung KIM ; Negussie RETTA ; Gulelat DESSIE ; Sang Ki RHEE ; Kwangoh KOH ; Kung Woo NAM ; Hee Seon KIM
Biomolecules & Therapeutics 2013;21(2):146-152
This study examined the total polyphenol content of eight wild edible plants from Ethiopia and their effect on NO production in Raw264.7 cells. Owing to its relatively high polyphenol concentration and inhibition of NO production, the methanol extract of Adansonia digitata L. leaf (MEAD) was subjected to detailed evaluation of its antioxidant and anti-inflammatory effects. Antioxidant effects were assessed by measuring free-radical-scavenging activity using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and oxygen-radical-absorbance capacity (ORAC) assays, while anti-inflammatory effects were assessed by measuring inducible nitric oxide synthase (iNOS) expression in lipopolysaccharide (LPS)-stimulated RAW264.7 cells. In the ORAC assay, MEAD was 10.2 times more potent than vitamin C at eliminating peroxyl radicals. In DPPH assay, MEAD also showed a strong ROS scavenging effect. MEAD significantly inhibited iNOS activity (IC50=28.6 microg/ml) of LPS-stimulated Raw264.7 cells. We also investigated the relationship between iNOS expression and nuclear factor kappa B (NF-kappaB) activation. MEAD inhibited IkappaBa degradation and NF-kappaB translocation from the cytosol to the nucleus in LPS-induced RAW264.7 cells without significant cytotoxic effects, as confirmed by MTT assay. These results suggest that MEAD inhibits anti-inflammatory iNOS expression, which might be related to the elimination of peroxyl radicals and thus the inhibition of IkappaBa-mediated NF-kappaB signal transduction.
Adansonia*
;
Antioxidants
;
Ascorbic Acid
;
Cytosol
;
Ethiopia
;
Methanol*
;
NF-kappa B*
;
Nitric Oxide Synthase Type II
;
Plants, Edible
;
Signal Transduction