• The Journal of Advanced Prosthodontics
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• v.12 no.6
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• pp.376-382
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• 2020

PURPOSE. To determine the shear bond strengths of different denture base resins to different types of prefabricated teeth (acrylic, nanohybrid composite, and cross-linked) and denture teeth produced by computer-aided design/computer-aided manufacturing (CAD/CAM) technology. MATERIALS AND METHODS. Prefabricated teeth and CAD/CAM (milled) denture teeth were divided into 10 groups and bonded to different denture base materials. Groups 1-3 comprised of different types of prefabricated teeth and cold-polymerized denture base resin; groups 4-6 comprised of different types of prefabricated teeth and heat-polymerized denture base resin; groups 7-9 comprised of different types of prefabricated teeth and CAD/CAM (milled) denture base resin; and group 10 comprised of milled denture teeth produced by CAD/CAM technology and CAD/CAM (milled) denture base resin. A universal testing machine was used to evaluate the shear bond strength for all specimens. One-way ANOVA and Tukey post-hoc test were used for analyzing the data (α=.05). RESULTS. The shear bond strengths of different groups ranged from 3.37 ± 2.14 MPa to 18.10 ± 2.68 MPa. Statistical analysis showed significant differences among the tested groups (P<.0001). Among different polymerization methods, the lowest values were determined in cold-polymerized resin.There was no significant difference between the shear bond strength values of heat-polymerized and CAD/CAM (milled) denture base resins. CONCLUSION. Different combinations of materials for removable denture base and denture teeth can affect their bond strength. Cold-polymerized resin should be avoided for attaching prefabricated teeth to a denture base. CAD/CAM (milled) and heat-polymerized denture base resins bonded to different types of prefabricated teeth show similar shear bond strength values.

• Journal of Technologic Dentistry
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• v.30 no.2
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• pp.47-56
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• 2008

This is a research for thickness change of denture base according to the shape of sprue & investment position of denture base in flask when injecting polyamid base resin for flexible partial denture as a part of study for Valplast among the flexible partial denture with a nylon base. It has been introduced several kinds of flexible partial denture product with a nylon base, but Valplast is the most widely used product among them. Valplast has been the most generally used material today since developed in 1950s in the United States as a material for flexible partial denture. Valplast is much more aesthetic than general metal-acrylic partial denture due to its translucent pink color and biocompatibility in terms of material characteristic. It keeps its flexibility for a long time after production, imposes a less burden on the teeth used as abutment, and it can be easily insert and remove due to its particular suppleness. Moreover, it is felt like real teeth more than metal-acrylic partial denture when being put in and takes alveolar bone under good protection since it receives occlusal force equally under the denture base. The most outstanding feature of Valplast is flexibility. The extent of its flexibility is determined by width & thickness of denture base. Considering general working procedure of Valplast, it can be seen that the thickness of denture base formed out of wax is increasing by the pressure while injecting resin. This research is to decide and test on the thickness increasing of Valplast by injecting pressure and the hypothesis upon that and is to prepare the basis estimating the increasing extent of thickness of denture base on the basis of the test result. In this test, it is expected occlusal malposition & thickness increasing of denture base by injecting pressure according to 4 kinds of test data which are to select 3 types of sprue method settling the forefront position at which the test material of fixed standard can be invested and to position the test material at the rearmost part keeping the minimum distance to set sprue. For 4 kinds of injecting test by investment position & sprue type, 20 test materials, 5 for each test were produced and a pressure of 1,180Kg was given with automatic injector of air cylinder type. The results are as follows: 1. For the amount of thickness increasing of denture base by investment position, the thickness of front investment is less increasing than the one of rear investment. 2. For the amount of thickness increasing of denture base by sprue type, the thickness of straight decompression sprue type which can absorb the injecting pressure after injecting polyamide base resin is less increasing than the other sprue types.

• The Journal of Korean Academy of Prosthodontics
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• v.41 no.4
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• pp.493-502
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• 2003

Statement of problem : Removable partial denture and complete denture often require denture base relines to improve the fittness against tissue-bearing mucosa because of the gradual change in edentulous ridge contour and resorption of underlyng bony structure. Self-curing hard reline resins offers the immediate and relatively inexpensive means to be recondition the surface of denture base directly However weak bond between denture base resin and reline material can harbor bacteria, promote staining, or result in complete separation of the two materials. Purpose : The purpose of this study was to evaluate the effect of denture cleansers on bond strength and surface hardness of reline resin to denture base resin Denture base resin beams($60.0{\times}15.0{\times}3.0mm$) were made with Lucitone 199. Material and methods : 10mm section was removed from the center of each specimen. The samples were replaced in the molds and the space of l0mm sections were packed with Tokuso Rebase reline material. The specimens were immersed in denture cleansers (Polident, Cleadent) and were evaluated after 1 week, 2 weeks, and 4 weeks. The bond strength and surface hardness of self-curing hard reline materials to heat-curing denture base resin were measured using an UTM (universal testing machine). Results and conclusion : 1) There was no significant difference of usage, kind, and denture cleaner by application time on the bonding strength of self-curing hard reline resin to denture base resin. 2) There was no significant difference of usage, kind, and denture cleaner by application time on the surface hardness, but the surface hardness showed decreasing tendency, as the time of immersion was extended. 3) The failure modes of the specimens was initially adhesive failure and finally cohesive failure of self-curing hard reline resin.

• Journal of Technologic Dentistry
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• v.40 no.4
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• pp.225-230
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• 2018

Purpose: The purpose of this study was to evaluate the effect of denture cleansers on the flexural bond strength of heat curing denture base resin and reliners. Methods: The denture base resin was bonded to the reliners(vertex self curing, kooliner, rebase II) to make the specimen. The specimens were immersed in denture cleansers(Polident, Cleadent) and evaluated after 1week, 3week, 5weeks. After denture reliners were injected, flexural bond strength was measured. Results: The bond strength of denture base resin and vertex self curing resin as reliner was significantly decreased at 5 weeks in cleadent and polident(p<0.05). The bond strength of kooliner and rebase II was significantly decreased at 5 weeks in denture cleaners(p<0.05). Kooliner was significantly decreased at 3 and 5 weeks in polident and rebase II was significantly decreased at 3 and 5 weeks in all denture cleansers(p<0.05). Conclusion : The flexural strength between the denture base resin and the reliners decreased significantly as the treatment time increased.

• Journal of Technologic Dentistry
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• v.20 no.1
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• pp.21-25
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• 1998

A detailed description of the Laboratory Processing procedures for Soft Base Denture that varies from those offered by the manufacturer has provid to be effective. As follows ; 1. Pomotion of patient's comfortability 2. increase in denture retention 3. because of the same heat-curing denture materials used improves bonding & endurance 4. often used denture refitting 5. reducing the rate of alveolar absorption The processing for soft base denture is very sensitive, consequntly.

• Journal of Dental Rehabilitation and Applied Science
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• v.37 no.4
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• pp.232-243
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• 2021

Purpose: The purpose of this study was to evaluate the shear bond strength of various 3D printed denture base resins and the conventional denture base resin to various denture relining materials. Materials and Methods: For denture base materials, a heatcured (Vertex RS) and two types of 3D printed DENTCA Denture base II, NextDent^TM Base) were used. And 4 types denture relining materials (Tokuyama Rebase II fast, Kooliner, Denture Liner, Denture Liner, Lang Jet Denture Repair Kit) with different components were used. It was classified into 12 groups. Adhesion was performed between the resin base and the relining materials in accordance with ISO/TS 11405 standard. The shear bonding strength was measured, and then the adhesion interface was observed with a stereoscopic microscope and a scanning electron microscope. The fracture pattern was investigated through the analysis of the fragment. Results: In the 3D printed denture resin group, the shear bonding strength with relining materials was significantly lower than that of the heat-cured resin group (P < 0.05). The group of polymethyl methacrylate -based relining materials, high shear bonding strength was shown regardless of the type of denture. As for the fracture pattern, adhesive fracture appeared in most groups, and cohesive, mixed fracture appeared in some groups. Conclusion: The polymethyl methacrylate -based denture relining materials showed high shear bonding strength values compared to other denture relining materials. But, for direct methods, it is considered advantageous in terms of shear bonding strength to use a isobutyl methacrylate-based denture relining materials.

• The Journal of Korean Academy of Prosthodontics
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• v.31 no.4
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• pp.523-531
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• 1993

The purpose of this study was to investigate the color change of denture base resins by coffee. Denture base resins for this study were Triad VLG Denture Base (Dentsply, York Div. U.S.A.), Premium Super-20 (Lang Dental Mfg. Co., Inc., U.S.A.) for denture base, Toughron Rebase (Miki Chemical Prod., Kyoto, Japan), Jet Repair Acrylic (Lang Dental Mfg. Co., Inc., U.S.A.), Triad Reline (Dentsply, fork Div. U.S.A.) and Tokuso Rebase (Tokuyama Soda Co., Ltd., Japan) for denture rebase. Twenty specimens of each denture base resin were made and polished. The color of specimens was measured by colorimeter (Model Tc-6FX, Tokyo Denshoku Co. Japan), and they were stored in coffee for three weeks and then color changes were measured. The obtained results were as follows : 1. The L*, a*, b* and the E*ab values of all denture base resins were changed after three weeks. 2. The amount of color change on L*, a*, b* and the E*ab value of each specimens showed different patterns. 3. The b* values of Triad Reline materials were changed more than the other materials. 4. The E*ab values of Triad Denture Base materials were changed more than the other materials.

• The Journal of Advanced Prosthodontics
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• v.11 no.1
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• pp.32-40
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• 2019

PURPOSE. The purpose of this study was to compare mechanical and physical properties of injection-molded thermoplastic denture base resins. MATERIALS AND METHODS. In this study, six commercially available products (VA; Valplast, LC; Lucitone, ST; Smiltone, ES; Estheshot-Bright, AC; Acrytone, WE; Weldenz) were selected from four types of thermoplastic denture base materials (Polyamide, Polyester, Acrylic resin and Polypropylene). The flexural properties and shore D hardness have been investigated and water sorption and solubility, and color stability have evaluated. RESULTS. For the flexural modulus value, ES showed the highest value and WE showed significantly lower value than all other groups (P<.05). Most of experimental groups showed weak color stability beyond the clinically acceptable range. CONCLUSION. Within the limits of this study, thermoplastic denture base resin did not show sufficient modulus to function as a denture base. In addition, all resins showed discoloration with clinical significance, and especially polyamides showed the lowest color stability.

• Journal of Dental Rehabilitation and Applied Science
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• v.18 no.3
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• pp.197-204
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• 2002

Polymers are the dominant material for fabrication of denture bases. However, resin base can't fufill the patients' satisfactions completely and solve the pronunciation problem and prevent the denture fracture. In spite of many advantages, metal denture bases do not widespread in clinical practice. The main reasons are the difficulties in fabrication and additional time and cost, inability to rebase such prostheses. The use of the metal base can be one of options in complete denture treatments. This study helps, through reveiwing previous reports and literature about the metal base, metal base to be useful in the clinical application by recommend the materials, indications and advantage/disadvantage of the metal base and introduce variable designs. The clinical application of the metal base have many advantages, but the dentists have to select cases carefully and apply designs according to patient's various conditions. In conclusion, the use of the metal base can't alternate treatment of inadequate conventional complete denture. Adequate complete denture is very important for the treatment of the metal base complete denture.

• Journal of Technologic Dentistry
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• v.37 no.4
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• pp.219-227
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• 2015

Purpose: The purpose of this study was to evaluate the effect of the chemical surface treatment on the flexural bond strength of heat curing denture base resin and reliners. Methods: Denture base resin surface was treated with MMA 95% and TEGDMA 5%, MMA 95% and silane coupling agent 5%, heat curing resin monomer. After denture reliners were injected, flexural bond strength was measured. Results: The repair resin of Vertex SC was higher than Lang, hard reliner of Kooliner was higher than Rebase. Soft reliner of Dura base and Coe-soft showed differently according to the surface treatment. The all chemical treatment groups on Vertex SC were significantly higher than control(p<0.05). In Lang group, 5% MPS treated group showed significantly higher flexural bond strength than others(p<0.05). In Kooliner group, all chemical treatment groups showed significantly higher than control(p<0.05). In Rebase group, the 5% MPS and the monomer denture base resin treated groups showed significantly higher than others(p<0.05). In Dura base group, 5% MPS treated group showed significantly higher flexural bond strength than others(p<0.05). In Coe-soft group, all treated groups were significantly higher than control group(p<0.05). Conclusion: TEGDMA, MPS, and the monomer of heat-cured denture base resin were effective to improve the bond strengths between denture base and denture relining materials. Especially, 5% MPS expected to strengthen effectively the bonding property of denture base and denture reliners within the results of this study.