• The Journal of Korean Academy of Prosthodontics
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• v.39 no.1
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• pp.37-48
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• 2001

Ceromers, new indirect resin system, are now being adopted for esthetic restorations. Despite of its translucency and good color matching, color stability after long-term use was unknown till now. This in vitro study was designed to evaluate color stability of some ceromers when subjected to brushing after thermocycling. Three types of ceromers: Scupture, Targis, Artglass and a direct resin system, Z100 were prepared to disks 12 mm in diameter, 2.5 mm in thickness. All specimens were polished, and Sculpture and Targis specimens were divided two groups, respectively. Then, half of them were glazed according to manufacturer's instructions. All specimen were brushed 20,000 times after 10,000 cycle thermocycling. Color was measured with spectrophotometer after 1,000, 3,000, 10,000 times thermocycling and 20,000 time brushing, respectively. Color difference (${\Delta}E$) was calculated according to CIE LAB system. During thermocycling, Sculpture & Targis system with polished surface showed greater color change than any other groups. After brushing, color difference was reduced significantly. Mean values of ${\Delta}E$ ranged 0.98 to 2.98. All Ceromers were considered clinically acceptable after thermocycling and brushing, and color change mechanism was affected by the brands and finishing methods. It might be concluded that color change of ceromer is due to surface alteration.

• Proceedings of the KACD Conference
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• 2003.11a
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• pp.571-571
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• 2003

Composite inlays are indicated for large cavities and different approaches have been proposed to improve the adaptationof Class II restorations, including applying base. The purpose of this study was to compare in vitro the marginal adaptation of class II(MOD) composite inlays(Tescera ATL system, Bisco) made with or without bases, having different physical properties. Extracted human lower molars were used for this study. The base was made from Aeliteflo(Bisco), Dyract AP(Bisco) or Fuji II LC improved(GC) respectively and the comtrol group has no base.(omitted)

• International Journal of Oral Biology
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• v.46 no.4
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• pp.184-189
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• 2021

When luting indirect restorations with dual-cure resin cement (DCRC), excess cement can be easily removed by performing tack cure of DCRC for a few seconds. The purpose of this study was to evaluate whether different tack cure times affect polymerization shrinkage (PS) of the selected DCRC. One dual-cure resin cement (G-CEM LinkAce, GC) was used for measuring PS in light-cure (LC group), self-cure (SC group), and two tack-cure modes. In the first tack-cure subgroup, tack cure was performed for 1, 2, 3, and 5 seconds, followed by light cure after 2 minutes of remnant removal time in each case (TC-LC groups). In the other tack-cure subgroup, tack cure was performed for the same lengths of time, but followed by self-cure in each case (TC-SC groups). PS was measured by a modified bonded disc method for 1,800 seconds. One-way analysis of variance followed by Duncan's post hoc test was used to determine any statistically significant differences among the test groups (α = 0.05). When the DCRC was self-cured after tack cure, PS was significantly lower than when it was only self-cured (p < 0.05); however, tack cure time did not affect PS (p > 0.05). When the DCRC was light-cured, PS was not affected by tack cure or tack cure time (p > 0.05). Therefore, tack cure within 5 seconds did not negatively affect the final PS when the DCRC was light-cured after cement remnant removal.

• Restorative Dentistry and Endodontics
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• v.44 no.3
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• pp.27.1-27.12
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• 2019

This case report describes a technique in which endodontic treatment and permanent indirect restoration were completed in the same clinical appointment with the aid of a computer-aided design/computer-aided manufacturing (CAD/CAM) system. Two patients were diagnosed with irreversible pulpitis of the mandibular first molar. After access preparation, root canals were located, irrigation was performed until bleeding ceased, and the coronal tooth structure was prepared for indirect restoration. Then, utilizing an interim 3-mm build-up of the endodontic access cavity, a hemi-arch digital scan was performed with an intraoral scanner. Subsequent to digital scanning, restoration design was performed simultaneously with the endodontic procedure. The root canals were shaped using the Race system under irrigation with 2.5% sodium hypochlorite followed by root canal filling. The pulp chamber was subsequently filled with a 3-mm-thick composite resin restoration mimicking the interim build-up previously utilized to facilitate block milling in the CAD/CAM system. Clinical try-in of the permanent onlay restoration was followed by acid etching, application of a 5th generation adhesive, and cementation of the indirect restoration. Once the restoration was cemented, rubber dam isolation was removed, followed by occlusal adjustment and polishing. After 2 years of follow-up, the restorations were esthetically and functionally satisfactory, without complications.

• Journal of the Korean Academy of Esthetic Dentistry
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• v.17 no.1
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• pp.23-30
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• 2008

Application of CAD/CAM is changing the way partial or full veneer all ceramic restoration is made. CAD/CAM systems, which were used mainly in other industries, have been developed and introduced for the dental purposes recently. It produced a flood of information on the CAD/CAM systems. It also influenced the development of restorative materials and all ceramic is substituting the traditional restorative materials of gold, composite resin and metal. Price increase of gold and other raw materials made the all ceramic more appealing. The introduction of a CEREC 3D system was innovative in several ways. Image of the prepared tooth is captured by camera and impression taking is unnecessary. Restoration can be delivered to the patient on one appointment and it will satisfy the demand of busy patients. One-day treatment with direct CAD/CAM system saves time compared to indirect CAD/CAM system. More superior restoration can be produced if lab work such as the adaptability check and shade selection is cooperated with lab technician. Short working time and comparably superior shade compatibility of color block was close to ideal. In the future, restorations with better quality can be fabricated in less time to busy patients thanks to the development of CAD/CAM system and dental materials.

• The Journal of Korean Academy of Prosthodontics
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• v.46 no.4
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• pp.372-380
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• 2008

Purpose: The purpose of this study was to evaluate the effect of various methods of dentin bonding agent application on microtensile bond strength between dentin and resin, using a 2-step etch-and-rinse dentin bonding agent. Material and methods: Twenty freshly extracted human molars were obtained and divided into 4 groups of 5 teeth. 2-step etch-and-rinse dentin bonding agent was used for all groups. The control specimens were prepared using a direct immediate bonding technique. The delayed dentin sealing (A, C) specimens were prepared using an indirect approach with delayed dentin sealing. For group A, resin was built-up on uncured dentin bonding agent, and for group C, resin was built-up on pre-cured dentin bonding agent. Preparation of the immediate dentin sealing (B) specimens also used an indirect approach with immediate dentin sealing immediately following preparation. All teeth were prepared for a microtensile bond strength test. Specimens were stored in water for 24 hours. Ten beams (1.0 ${\times}$ 1.0 ${\times}$ 11 mm) from each tooth were selected for testing. Bond strength data (MPa) were analyzed with a one-way ANOVA test, and post hoc comparison was done using the Scheffe's test. Results: The mean microtensile bond strengths of control group, B and C (DDS with pre-cure) were not statisticaaly different from each other at 32.7, 33.3, 34.2 MPa. the bond strength for group A (DDS without pre-cure), 19.5 MPa, was statistically different (P < .01) from the other 3 groups. Conclusion: When preparing teeth for indirect bonded restorations, DDS with pre-curing dentin bonding agent and IDS results in the same bond strength between dentin and resin. On the contrast, the bond strength was decreased when DDS without pre-curing dentin bonding agent was used.

• Restorative Dentistry and Endodontics
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• v.33 no.6
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• pp.526-536
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• 2008

The purpose of this study was to compare the effect of various dentin bonding systems on microtensile bond strength of immediate dentin sealing (IDS) and delayed dentin sealing (DDS). Eighteen extracted permanent molars were used in this study. The teeth for DDS group were restored with a provisional restorations, and immersed in saline solution for 1 week, and divided into 3 subgroups according to various dentin bonding adhesives; SB subgroup (3 step total-etch adhesive), SE subgroup (2 step self-etch adhesive), XE subgroup (1 step self-etch adhesive). In IDS group, the teeth were divided into 3 subgroups, and applied with bonding adhesives as in DDS group. The teeth were restored with provisional restorations, and immersed in saline solution for 1 week. Indirect composite disc was cemented with resin cement, and all specimens were subjected to microtensile bond strength. The data were statistically analyzed with oneway ANOVA and Student t-test. The results were as follows: 1. The IDS group showed significantly higher ${\mu}TBS$ than DDS group in 3 step total-etch and 2 step selfetch adhesive (p < 0.05). 2. In IDS and DDS group, 3 step total-etch adhesive showed the highest ${\mu}TBS$ value, followed by 2 step self-etch, and 1 step self-etch adhesive. In IDS group, the ${\mu}TBS$ value for 1 step self-etch adhesive was significantly different from those of the other subgroups (p < 0.05), and in DDS group, there were statistical differences in all subgroup (p < 0.05). 3. Failure modes of tested dentin bonding adhesives were mostly mixed failure and only 1 step self-etch adhesive showed adhesive failure.

• The Journal of Korean Academy of Prosthodontics
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• v.48 no.1
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• pp.8-15
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• 2010

Purpose: The purpose of this study was to evaluate the effect of various methods of dentin bonding agent application and air abrasion pretreatment on microtensile bond strength between dentin and resin, using a self-etching adhesive system. Material and methods: Thirty freshly extracted human molars were obtained and divided into 6 groups of 5 teeth. A 2-step self etching adhesive system (Clearfil SE Bond) was used for all groups. The control specimens were prepared using a direct immediate bonding technique. The delayed dentin sealing specimens were prepared using an indirect approach without dentin prebonding. The immediate dentin sealing specimens were prepared using dentin prebonding immediately following preparation. Immediate dentin sealing teeth and delayed dentin sealing teeth had provisional restorations using Fermit for two weeks. Then all specimens of each group were divided into two groups of three, depending on air abrasion pretreatment. Composite "crowns" were incrementally built on and specimens were stored in water for 24 hours. All teeth were prepared for a microtensile bond strength test. Bond strength data were analyzed with a one-way ANOVA test, and post hoc comparison was done using the Scheffe's test. Results: The mean microtensile bond strengths of all groups were not statistically different from each other. Conclusion: When preparing teeth for indirect restorations, IDS and DDS with Clearfil SE bond, have no difference on the microtensile bond strength between dentin and resin. Air abrasion pretreatment did not affect the microtensile bond strength when using IDS and DDS with Clearfil SE bond.