1.Resin-bonded fixed partial denture using In-Ceram and Targis-Ventris system.
The Journal of Korean Academy of Prosthodontics 2000;38(3):375-381
Resin-bonded fixed partial denture using In-Ceram or Targis-Vectris system allows conservative replacement of missing maxillary lateral incisor, but sufficient clinical crown length and adequate occlusal clearance are necessary for restoration. Resin-bonded fixed partial dentures using In-Ceram or Targis-Vectris system require only minor tooth preparation and allow access to maintain esthetics and periodontal health. Longitudinal studies are needed to verify theefficacy of all-ceramic or fiber-reinforced composite RBFPDs.
Crowns
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Denture, Partial, Fixed
;
Denture, Partial, Fixed, Resin-Bonded*
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Esthetics
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Incisor
;
Tooth Preparation
2.Fiber Reinforced Inlay Adhesion Bridge.
Lee Ra CHO ; Yang Jin YI ; Ho Yong SONG
The Journal of Korean Academy of Prosthodontics 2000;38(3):366-374
FRC/ceromer system provides the clinician with a durable, flexible, and esthetic alternative to conventional porcelain fused to metal crowns. FRC is the matrix which is silica-coated and embedded in a resin matrix. The ceromer material which is a second generation indirect composite resin contains silanized, microhybrid inorganic fillers embedded in a light-curing organic matrix. FRC/ceromer restoration has a several advantages: better shock absorption, less wear of occluding teeth, translucency, color stability, bonding ability to dental hard tissues, and resiliency. It has versatility of use including inlay, onlay, single crown, and esthetic veneers. With adhesive technique, it can be used for single tooth replacement in forms of inlay adhesion bridge. In single tooth missing case, conventional PFM bridge has been used for esthetic restoration. However, this restoration has several disadvantages such as high cost, potential framework distortion during fabrication, and difficulty in repairing fractures. Inlay adhesion bridge with FRC/ceromer would be a good alternative treatment plan. This article describes a cases restored with Targis/Vectris inlay adhesion bridge. Tooth preparation guide, fabrication procedure, and cementation procedure of this system will be dealt. The strength/weakness of this restoration will be mentioned, also. If it has been used appropriately in carefully selected case, it can satisfy not only dentist's demand of sparing dental hard tissue but also patient's desire of seeking a esthetic restorations with a natural appearance.
Absorption
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Adhesives
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Cementation
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Crowns
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Dental Porcelain
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Inlays*
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Shock
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Tooth
;
Tooth Preparation
3.Restoration of Mandibular Edentulous Patient By Dental Implant.
The Journal of Korean Academy of Prosthodontics 2000;38(3):360-365
The completely edentulous patient has few treatment options in conventional dentistry. When implants are considered, treatment plans range from a 2-implant overdenture to a completely implant-supported prosthesis. Fixed prosthesis is often the preferred selection of the edentulous patient. fixed full-arch ceramo-metal restorations can be a predictable implant treatment modality for the edentulous patient. Implant-supported fixed prosthesis has several advantages: predictability, fixedness, retrievability, improved function, lower maintenance of prosthesis, long-term published success. Edentulous patients with a severely resorbed mandible often experience problems with their dentures. Treatment concepts involving two to four implants for the support of an overdenture have been proposed. There seems to be no need to insert more than two endosteal implants to support an overdenture, however, long-term prospective studies are needed to support this notion. Using short endosseous implants and an overdenture in the extremely resorbed mandible is a justified treatment option because of the relative simplicity and low morbidity of this treatment strategy. Implant-supported overdenture has several advantages: Cost, retrievability, hygiene access, profile and contour control, increasedretention and stability, implant installed in a predicted region(ant. mandible).
Dental Implants*
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Dentistry
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Denture, Overlay
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Dentures
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Humans
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Hygiene
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Mandible
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Prostheses and Implants
4.On the effects of the characteristics of the titanium oxide to the osteoblast cell culture.
The Journal of Korean Academy of Prosthodontics 2000;38(3):358-359
STATEMENT of PROBLEM: Confusion about the relationship of surface characteristics of implant to osteoblast cell attachment. PURPOSE: This study attempted to bone cell attachment to the implant surface which was modified by heat. MATERIAL AND METHODS: Commercially pure titanium grade 2, 4x4mm sheet 40 pieces were treated for 10 minutes with ultrasonic cleaner with methylethyl ketone, ethanol, deionized distilled water, and half of the specimen 20 pieces were heat treated in 980degreesC for 15 minutes. All 40 specimens were autoclaves. Total 6 dishes were prepared, 3 dishes were for control group, and the other 3 dishes were for heat treatment. In fourth day, cell account was done. CONCULSION: The change of surface characterization by heat treatment could affect the cell attachment in the early stage however, the change of surface characterization would not be prolonged.
Cell Culture Techniques*
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Ethanol
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Hot Temperature
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Osteoblasts*
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Titanium*
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Ultrasonics
;
Water
5.The influence of screw type and osseointegration ratio on stress distribution in two different endosseous implants.
The Journal of Korean Academy of Prosthodontics 2000;38(3):348-357
The purpose of this study is to examine the effect of partial osseointegration situation on bone loading patterns around two different free-standing screw shaped implants (Nobel Biocare, Gothenburg, Sweden and Degussa-Huls, Hanau, German). Two dimensional axisymmetric Finite element models of two implants(10mm length and 4mm diameter) were created according to different bone quantity, quality and osseointegration ratio in maxilla and mandible bone. At the same time uni-cortical and bi-cortical fixation were analyzed. Generally, full bond case showed less stress than partial bond case in overall area and mandibular model showed less amount of stress than that of maxilla model. Maximum stress of the Branemark implant is higher than that of ANKYLOS regardless of bondingratio at crestal and apex region. However, more stress concentration was noted in ANKYLOS implant at screw body area especially in mandible. The effect of bicortical fixation on crestal bone stress reduction is dramatical in mandible however, there was no significant effect in maxillary case. The effect of partial bond on stress distribution was more significant at screw body and apex region than in crestal region. Partial bond cases demonstrated greater stress accumulation in trabecular bone than cortical bone. It is concluded that the more accurate model of implant and bone which affects stress and strain distribution is needed to mimic in vivo behavior of implants.
Mandible
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Maxilla
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Osseointegration*
;
Sweden
6.Comparison of the bond strength of ceramics fused to titanium and Ni-Cr alloy.
Sae Young PARK ; Young Chan JEON ; Chang Mo JEONG
The Journal of Korean Academy of Prosthodontics 2003;41(1):89-98
Titanium requires special ceramic system for veneering. Low fusing dental ceramics with coefficients of thermal expansion matching that of titanium have been developed. The purpose of this study was to determine the bond strengths between cast and noncast pure titanium and two commercial titanium porcelains, and to compare the results with a conventional nickel-chromium alloyceramic system. The bond strengths were determined using a 3-point flexure test. Three-point flexure specimens 25x3x0.5mm were prepared. After removal of alpha-case layer, they were veneered with 8x3x1mm of ceramics at the center of the bar. Specimens were tested in a universal testing machine. Within the limits of this study, the following conclusions were drawn: 1. The bond strengths between pure titanium and two commercial porcelains exceeded th lower limit of the bonding strength value in ISO 9693(25MPa). 2. There was no significant difference between cast and noncast titanium-porcelain bonds. 3. There was no significant difference between two commercial titanium porcelains. 4. The bond strengths of the titanium-porcelain systems ranged from 73% to 79% of that of the Ni-Cr-conventional porcelain system.
Alloys*
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Ceramics*
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Dental Porcelain
;
Titanium*
7.Effect of impression technique on the accuracy of master cast for implant prosthesis.
The Journal of Korean Academy of Prosthodontics 2004;42(2):238-247
STATEMENT OF PROBLEM: Major objective in making on implant-supported prosthesis is the production of superstructure that exhibits a passive fit when connected to multiple abutments. One requirement to ensure passive fit is to make an accurate impression. PURPOSE: The purpose of this study was to compare the accuracy of master cast fabricated by using different impression methods at the different impression levels. MATERIAL AND METHOD: The master model used in this study was resin block having four implant analogs. Impression method studied were 1) direct method on fixture level (Group FIX-D), 2) indirect method on fixture level(Group FIX-I), 3) modified indirect method on fixture level(Group FIXM) 4) direct method on abutment level(Group AB-D) and 5) indirect method on abutment level(Group AB-I). Each of the five groups took 10 impressions. Fifty impressions were made for master cast by using Impregum F. impression material loaded on individual tray. Three dimensional measuring microscope was used to measure the inter-implant distance. Error rate of each inter-implant distance were calculated and evaluated. RESULTS: The results were as follows. 1. Group FIX exhibited higher accuracy than group AB. 2. In group FIX, modified indirect method showed the highest accuracy, while indirect method showed the lowest accuracy. In group Ab, indirect method showed the higher accuracy than direct method. 3. Group FIX showed larger horizontal error than group AB. But, group AB showed the larger vertical error than group FIX. 4. Group Fix-M showed smallest vertical and horizontal error. CONCLUSION: An impression method have more effect on accuracy of master model than an impression level. A modified indirect method showed smallest vertical and horizontal error.
Prostheses and Implants*
8.Stress analysis of supporting tissues and implants according to implant fixture shapes and implant-abutment connections.
Sang Un HAN ; Ha Ok PARK ; Hong So YANG
The Journal of Korean Academy of Prosthodontics 2004;42(2):226-237
PURPOSE: Four finite element models were constructed in the mandible having a single implant fixture connected to the first premolar-shaped superstructure, in order to evaluate how the shape of the fixture and the implant-abutment connection would influence the stress level of the supporting tissues, fixtures, and prosthethic components. MATERIAL AND METHODS: The superstructures were constructed using UCLA type abutment, ADA type III gold alloy was used to fabricate a crown and then connected to the fixture with an abutment screw. The models BRA, END, FRI, ITI were constructed from the mandible implanted with Branemark, Endopore, Frialit-2, I.T.I systems respectively. In each model, 150 N of vertical load was placed on the central pit of an occlusal plane and 150 N of 40.oblique load was placed on the buccal cusp. The displacement and stress distribution in the supporting tissues and the other components were analysed using a 2-dimensional finite element analysis. The maximum stress in each reference area was compared. RESULTS: 1. Under 40.oblique loading, the maximum stress was larger in the implant, superstructure and supporting tissue, compared to the stress pattern under vertical loading. 2. In the implant, prosthesis and supporting tissue, the maximum stress was smaller with the internal connection type (FRI) and the morse taper type (ITI) when compared to that of the external connection type (BRA and END). 3. In the superstructure and implant/abutment interface, the maximum stress was smaller with the internal connection type (FRI) and the morse taper type (ITI) when compared to that of the external connection type (BRA and END). 4. In the implant fixture, the maximum stress was smaller with the internal connection type (FRI) and the morse taper type (ITI) when compared to that of the external connection type (BRA and END). 5. The stress was more evenly distributed in the bone/implant interface through the FRI of trapezoidal step design. Especially Under 40.oblique loading, The maximum stress was smallest in the bone/implant interface. 6. In the implant and superstructure and supporting tissue, the maximum stress occured at the crown loading point through the ITI. CONCLUSION: The stress distribution of the supporting tissue was affected by shape of a fixture and implant-abutment connection. The magnitude of maximum stress was reduced with the internal connection type (FRI) and the morse taper type (ITI) in the implant, prosthesis and supporting tissue. Trapezoidal step design of FRI showed evenly distributed the stress at the bone/implant interface.
Alloys
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Crowns
;
Dental Occlusion
;
Finite Element Analysis
;
Mandible
;
Prostheses and Implants
9.Effects of surface coating on the screw release of dental implant screw.
Cheol In KOO ; Chae Heon CHUNG ; Han Cheol CHOE
The Journal of Korean Academy of Prosthodontics 2004;42(2):210-225
STATEMENT OF PROBLEM: Implant screw loosening has been remained problem in restorative practices. Surface treatment of screw plays a role of preventing screw from loosening in implant screw mechanism. PURPOSE: The purpose of this study was to investigate surface characteristics of TiN and ZrN film ion plated screw with titanium and gold alloy screw and to evaluate wear resistance, surface roughness, and film adhesion on screw surface using various instruments. MATERIAL AND METHODS: GoldTite screws and titanium screws provided by 3i (Implant Innovation, USA) and TorqTite screws or titanium screws by Steri-Oss (Nobel Biocare, USA) and gold screws and titanium screws by AVANA (Osstem Implant, korea) were selected. Ion plating which is much superior to other surface modification techniques was carried out for gold screws and titanium screws using Ti and Zr coating materials with nitrogen gas. Ion nitrided surface of each abutment screw was observed with field emission scanning electron microscopy(FE-SEM), micro-diamond scratch tester, vickers hardness tester, and surface roughness tester. RESULTS: 1) The surface of gold screw and GoldTite is more smooth than ones of other kinds of non coated screw. 2) The ZrN and TiN coated surface is the more smooth than ones of other kinds of screw. 3) The hardness of TiN and ZrN coated surface showed higher than that of non coated surface. 4) The TiN coated titanium screw and ZrN coated gold screw have a good wear resistance and adhesion on the surface. 5) The surface of ZrN coated screw showed low surface roughness compared with the surface of TiN coated screw. CONCLUSION: It is considered that the TiN and ZrN coated screw which would prevent a screw from loosening can be appilcable to implant system and confirmed that TiN and ZrN film act as lubricant on surface of screw due to decrease of friction for recycled tightening and loosening.
Alloys
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Dental Implants*
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Friction
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Hardness
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Hardness Tests
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Nitrogen
;
Tin
;
Titanium
10.Finite element approach to investigate the influence of the design configuration of the ITI solid implant on the bone stresses during the osseointegration process.
Sang Bum CHA ; Kyu Bok LEE ; Kwang Hun JO
The Journal of Korean Academy of Prosthodontics 2006;44(2):217-228
STATEMENT OF PROBLEM: Standard type of ITI solid implant model in the 6.2mm thick jaw bone was axisymmetrically modelled for finite element stress analyses. PURPOSE: Primary objective was to investigate the influences of the characteristic design configuration of the ITI solid implant model on the bone stress with the course of osseointegration process at the bone/implant interfaces. To simulate the characteristics of the osseointegration process, five different stages of the bone/implant interface model were implemented. As load conditions, vertical load of 50N was taken into consideration. Bone at the cervical region of implant was the areas of concern where the higher level of stress were likely to take place. RESULTS: The results indicated that rather slightly different stress level could be obtained as a function of the osseointegration conditions. CONCLUSION: Under vertical load, the lower level of stress was observed at the cervical cortical bone in the initial and final stages of osseointegration. Relatively higher stress level, however, was observed during the transitional stages where the osseointegration at the cancellous bone interface were yet to fully develop.
Jaw
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Osseointegration*