• Proceedings of the KACD Conference
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• 2001.05a
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• pp.235-237
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• 2001

;Dentistry has benefited from tremendous advances in technology with the introduction of new techniques and materials, and patients are aware that esthetic approaches in dentistry can change one's appearance. Increasingly. tooth-colored restorative materials have been used for restoration of posterior teeth. Tooth-colored restoration for posterior teeth can be divided into three categories: 1) the direct techniques that can be made in a single appointment and are an intraoral procedure utilizing composites: 2) the semidirect techniques that require both an intraoral and an extraoral procedure and are luted chairside utilizing composites: and 3) the indirect techniques that require several appointments and the expertise of a dental technician working with either composites or ceramics. But, resin restoration has inherent drawbacks of microleakage. polymerization shrinkage, thermal cycling problems. and wear in stress-bearing areas. On the other hand, Ceramic restorations have many advantages over resin restorations. Ceramic inlays are reported to have less leakage than resin restoration and to fit better. although marginal fidelity depends on technique and is laboratory dependent. Adhesion of luting resin is more reliable and durable to etched ceramic material than to treated resin composite. In view of color matching, periodontal health. resistance to abrasion, ceramic restoration is superior to resin restorationl. Materials which have been used for the fabrication of ceramic restorations are various. Conventional powder slurry ceramics are also available. Castable ceramics are produced by centrifugal casting of heat-treated glass ceramics. and machinable ceramics are feldspathic porcelains or cast glass ceramics which are milled using a CAD/CAM apparatus to produce inlays (for example, Cered. They may also be copy milled using the Celay apparatus. Pressable ceramics are produced from feldspathic porcelain which is supplied in ingot form and heated and moulded under pressure to produce a restoration. Infiltrated ceramics are another class of material which are available for use as ceramic inlays. An example is $In-Ceram^{\circledR}$(Vident. California, USA) which consists of a porous aluminum oxide or spinell core infiltrated with glass and subsequently veneered with feldspathic porcelain. In the 1980s. the development of compatible refractory materials made fabrication easier. and the development of adhesive resin cements greatly improved clinical success rates. This case report presents esthetic ceramic inlays for posterior teeth.teeth.

• Journal of the korean academy of Pediatric Dentistry
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• v.33 no.2
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• pp.165-172
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• 2006

A direct pulp capping with different medicaments has been attempted for a long time. The most commonly used among those is the calcium hydroxide. In primary teeth, however, a success rate of direct pulp capping with calcium hydroxide has been reported to be lower than that of pulpotomy. The disappointing results of calcium hydroxide have prompted the search for other capping materials. Lately, several researchers suggested an application of adhesive resin-based composite systems as a capping material. They claimed that when an exposed vital pulp is capped directly with bonding resin, the pulp tissue is free of inflammation or necrosis without clinical symptoms. The aim of this study was to compare short-term effects of the bonding resin which was applied on the mechanically exposed vital pulp tissue and those of direct pulp capping with calcium hydroxide. The second objective was to compare success rates of the primary teeth which already underwent physiologic root resorption and those of the teeth which had not undergone physiologic root resorption yet, in each capping material groups. The vital, healthy pulp of forty-one primary teeth were exposed mechanically during a cavity preparation. They were divided into two groups: Group 1(n=21) underwent capping with bonding resin, and group 2(n=20) underwent capping with calcium hydroxide. Then these two groups were subdivided into two groups in each : the teeth which show physiologic root resorption and the teeth without root resorption. All of the sample teeth were restored with composite resin. Clinical evaluations such as percussion test, ice test, EPT, were recorded and also before- and after- standard x-ray films were compared and evaluated to decide whether the case was successful or not. Evaluation was performed at least 3 months after the capping materials. The results were as follows 1. There was no difference in success rate between group 1 and group 2. 2. Success rate of the teeth with physiologic root resorption was higher than that of the teeth without physiologic root resorption in group 1 and group 2. 3. There was no difference in success rate between anterior teeth and posterior teeth.

• Journal of Technologic Dentistry
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• v.43 no.3
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• pp.84-92
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• 2021

Purpose: The purpose of this study was to compare the dimension safety evaluation between a general ultrasonic cleaner and an ultrasonic cleaner equipped with UV-C (ultraviolet-C). Methods: An edentulous model was prepared. A denture base and an occlusal rim were fabricated, and scanning was performed. After scanning, a denture base and full arch artificial teeth were designed. The full arch artificial teeth were printed using a three-dimensional printer (n=10). The residual resin was washed with alcohol and then scanned (reference data). The printed specimens were classified and cleaned using a general ultrasonic cleaner (GU group) and an ultrasonic cleaner equipped with UV-C (UC group). After each washing, a rescan was performed (scan data). Reference data and scan data were superimposed using overlapping software. Data were statistically analyzed using the Mann-Whitney test (α=0.05). Results: In the deviation values of full arch artificial teeth, the GU group showed a high deviation of 18.02 ㎛ and the UC group showed a low deviation of 15.02 ㎛. The two groups demonstrated a statistically significant difference (p<0.05). Conclusion: Full arch artificial teeth prepared using photopolymerized resin were deformed according to the temperature of water generated in the ultrasonic cleaner. It is judged that there is no deformation according to the UV-C ultrasonic cleaner.

• Restorative Dentistry and Endodontics
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• v.26 no.4
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• pp.332-340
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• 2001

Flowable composite resin has lower filler content, increased flow, and lower modules of elasticity. It is suggested that flowable composite resin can be bonded to the tooth structure intimately and absorb or dissipate the stress. Therefore, it may be advantageous to use flowable composite resin for the base material of class II restoration and for the class V restoraton. The purpose of this study was to evaluate the microleakage and shear bond strength of four flowable composite resins (Aeliteflo, Flow-It, Revolution, Ultraseal XT Plus) compared to Z100 using Scotchbond Multi Purpose dentin bonding system. To evaluate the microleakage, notch-shaped class V cavities were prepared on buccal and lingual surfaces of 80 extracted human premolars and molars on cementum margin. The teeth were randomly divided into non-thermocycling group (group 1) and thermocycling group (group 2) of 40 teeth each. The experimental teeth of each group were randomly divided onto five subgroups of eight samples (sixteen surfaces). The Scotchbond Multi-Purpose and composite resin were applied for each group following the manufacturer's instructions. the teeth of group 2 were thermocycled five hundred times between 5$^{\circ}C$ and 55$^{\circ}C$. The teeth of group 2 were placed in 2% methylene blue dye for 24 hours, then rinsed with tab water. The specimens were embedded in clear resin, and sectioned longitudinally with a diamond saw. The dye penetration on each of the specimen were observed with a stereomicioscope at $\times$20 magnification. To evaluate the shear bond strength, 60 teeth were divided into five groups of twelve teeth each. The experimental teeth were ground horizontally below the dentinoenamel junction, so that no enamel remained. After applying Scotchbond Multi-Purpose on the dentin surface, composite resin was applied in the shape of cylinder. The cylinder was 4mm in diameter and 2mm in thickness. Shear bond strength was measured using Instron with a cross-head speed of 0.5mm/min. After shear bond strength measurement, mode of failure was evaluated with a stereomicroscope at $\times$30 magnification. All data were statistically analyzed by One Way ANOVA and Student-Newman-Keuls method. The correlation between microleakage and shear bond strength was analyzed by linear regression. The results of this study were as follows ; 1. In non-thermocycling group, the leakage value of Z100 was significantly lower than those of flowable composite resins at the enamel and dentin margin, margin, except that Revolution showed the lower leakage value than that of Z100 at the dentin margin (p<0.05). 2. In thermocycling group, the leakage values of Z100 and Ultraseal XT Plus were lower than those of other subgroup at the enamel and dentin margin, except that Flow-It showed the lower leakage value than that of Ultraseal XT Plus at the dentin margin (p<0.05). 3. The leakage value of Z100 and Ultraseal XT Plus in thermocycling group were not higher than that in non-thermocycling group at the enamel margin. The leakage value of Z100 in thermocycling group was not higher than that in non-thermocycling group at the dentin margin (p<0.05). 4. As for the shear bond strength measurement, there were no statistically significant differences among groups (p<0.05). The shear bond strengths given in descending order were as follows: Z100(16.81$\pm$2.98 MPa), Flow-It(14.8$\pm$4.43 MPa), Aeliteflo(14.34$\pm$3.69 MPa), Revolution(13.46$\pm$4.23 MPa), Ultraseal XT Plus(12.83$\pm$3.16 MPa). 5. Failure modes of all specimens were adhesive failures. 6. There was no correlation between microleakage and shear bond strength.

• The Journal of Korean Academy of Prosthodontics
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• v.38 no.5
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• pp.640-649
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• 2000

In the restoration of endodontically treated teeth, carbon fiber post was recently introduced. The purpose of this in vitro study was to investigate the fracture strength of teeth restored with a pre-fabricated carbon fiber post in comparison with teeth restored with a prefabricated titanium post & custom cast gold post after cyclic loading in the different environment. A total of 30 recently extracted human central incisors of similar dimension with crowns removed were used. All teeth were placed into acrylic blocks and every steps for post and core fabrication were made accord-ing to manufacture's instruction. The post length and core dimensions were standardizd. All teeth were divided into 6 groups: 1) carbon fiber post / atmosphere, 2) titanium post / atmosphere, 3) gold post / atmosphere, 4) carbon fiber post / wet, 5) titanium post / wet, 6) gold post / wet. Carbon fiber post and titanium post were cemented in place using resin cement and cores were fabricated with Ti-Core. Custom cast gold post was made from Duralay pattern resin and cemented using resin cement, too. All specimens were thermocycled 10,000 times. After 50,000 cyclic loading, failure strength was measured using Instron testing machine. Kruskal-Wallis test followed by Mann-Whitney test was used to compare the mean fracture strength. Results were as follows : 1. All specimens showed lower fracture strength in wet environment after cyclic loading than in atmosphere condition, but did not reveal a significant difference. 2. There was no significant difference between carbon fiber post specimen and titanium post specimen in the same environment. 3. Gold cast post specimen showed significant different greater fracture strength than those of others in the same environment. 4. Carbon fiber post specimen showed no root fracture.

• Journal of the korean academy of Pediatric Dentistry
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• v.45 no.3
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• pp.344-353
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• 2018

The purposes of this study were to evaluate microleakage of Biodentine, one of the tricalcium silicate based pulp-capping materials, and to compare the shear bond strength between composite resin and Biodentine with different setting times. For microleakage evaluation, 70 bovine teeth were used. Cavities were formed on the labial surfaces and filled with Biodentine. The teeth were divided into seven groups, each consisting of 10 teeth. The specimens were prepared by applying the composite resin on the upper side after different setting times. To evaluate shear bond strength, 210 acrylic resin blocks with central grooves were prepared, and the grooves were filled with Biodentine. The acrylic resin blocks were divided into seven groups of 30 specimens each, and the specimens were prepared by applying the composite resin on the upper side after different setting times. In samples with setting time of 24 hours or longer period, the microleakage between composite resin and Biodentine was reduced significantly while the shear bond strength increased to offset the polymerization shrinkage of the composite resin. Setting Biodentine for more than 24 hours before composite resin restoration would lead to more favorable clinical result.

• The Journal of the Korean dental association
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• v.57 no.3
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• pp.162-168
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• 2019

Composite resin restorations in posterior teeth are increasing due to the aesthetic needs of patients and the development of materials. This trend will accelerate in line with domestic insurance policies. However, resin composites generate stresses due to their contraction during the polymerization process. To reduce the polymerization shrinkage stress of resin composites, incremental layering technique has been recommended for decades. This technique reduces stress at the cavity wall interface and allows a more efficient light curing of the material. Bulk-fill resin composites have been designed to simplify the restorative technique because they can be placed into cavities in a single increment of 4-5mm. The simplification of the operative procedures is desirable in clinical daily practice. In this context, bulk-fill resin composites are an attractive alternative for posterior restorations. However, a clearer understanding of the clinical performance of this relatively new class of materials in comparison to conventional resin composites is required. Based on previous studies, the aim of the current review was to present the clinical criteria for the use of bulk-fill composites in direct restorations of posterior teeth.

• The Journal of Advanced Prosthodontics
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• v.7 no.4
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• pp.317-322
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• 2015

PURPOSE. The aim was to evaluate the effect of curing mode and different dentin surface pretreatment on microtensile bond strength (${\mu}TBS$) of self-adhesive resin cements. MATERIALS AND METHODS. Thirty-six extracted human permanent molars were sectioned horizontally exposing flat dentin surface. The teeth were divided into 12 groups (3 teeth/group) according to the dentin surface pretreatment methods (control, 18% EDTA, 10% Polyacrylic acid) and curing mode (self-curing vs. light-curing) of cement. After pretreatment, composite resin blocks were cemented with the following: (a) G-CEM LinkAce; (b) RelyX U200, followed by either self-curing or light-curing. After storage, the teeth were sectioned and ${\mu}TBS$ test was performed using a microtensile testing machine. The data was statistically analyzed using one-way ANOVA, Student T-test and Scheffe's post-hoc test at P<.05 level. RESULTS. For G-CEM LinkAce cement groups, polyacrylic acid pretreatment showed the highest ${\mu}TBS$ in the self-cured group. In the light-cured group, no significant improvements were observed according to the dentin surface pretreatment. There were no significant differences between curing modes. Both dentin surface pretreatment methods helped to increase the ${\mu}TBS$ of RelyX U200 resin cement significantly and degree of pretreatment effect was similar. No significant differences were found regarding curing modes except control groups. In the comparisons of two self-adhesive resin cements, all groups within the same pretreatment and curing mode were significantly different excluding self-cured control groups. CONCLUSION. Selecting RelyX U200 used in this study and application of dentin surface pretreatment with EDTA and polyacrylic acid might be recommended to enhance the bond strength of cement to dentin.

• Restorative Dentistry and Endodontics
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• v.25 no.2
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• pp.243-253
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• 2000

The purpose of this in vitro study was to evaluate dentin bonding by two different dentin bonding systems(DBS) using acetone based primer or adhesive [All Bond 2(AB2), One Step(OS)] when they were applied by wet or dry bonding technique. Morphology of resin-dentin interface and hybrid layer thickness(HLT) were investigated using Confocal Laser Scanning Microscope(CLSM) and compared to shear bond strength(SBS). 72 extracted sound human molars were randomly divided into 4 groups of 18 teeth each - Group 1.(AW); AB2 by wet bonding. Group 2(AD); AB2 by dry bonding. Group 3.(OW); OS by wet bonding, Group 4.(OD); OS by dry bonding. In 6 teeth of each group, notch-shaped class V cavities(depth 2mm) were prepared on buccal and lingual surface at the cementoenamel juction(12 cavities per group). To obtain color contrast in CLSM observation, bonding resins of each DBS were mixed with rhodamine B and primer of AB2 was mixed with sodium fluorescein. Prepared teeth of each group were treated with AB2, OS, respectively according to the manufacturer's instructions except for dentin surface moisture treatment after acid etching. In group 1 and 3, after acid etching, excess water was removed with wet tissue(Kimwipes), leaving consistently shiny, visibly hydrated dentin surface. In group 2 and 4, dentin surface was dried for 10 seconds at 1 inch distance. The treated teeth were then packed with composite resin(${\AE}$litefil) and light-cured. 12 microscopic samples($60{\sim}80{\mu}m$ thickness) of each group were obtained after longitudinal section and grinding(Exakt cutting and grinding system). Morphological investigation of resin-dentin interface and HLT measurement using CLSM were done. For measurement of SBS, remaining 12 teeth of each group were flattened occlusally to remove all enamel and grinded to 500 grit SiC(Pedemet Specimen Preparation Equipment). After applying DBS on the exposed dentin surface, composite resin was applied in the shape of cylinder, which has 5mm diameter, 1.5mm thickness, and light cured. SBS was measured using Instron with a crosshead speed of 0.5mm/min. It was concluded as follows, 1. HLT of AW(mean: $2.59{\mu}m$) was thicker than any other group, and followed by AD, OW, OD in descending order(mean; 2.37, 2.28, $1.92{\mu}m$). Only OD had statistically significant differences(p<0.05) to AW and AD. 2. There were intimate contact of resin and dentin at the interface in wet bonding groups, but gaps or irregular interfaces were observed in dry bonding groups. 3. The length, diameter, density of resin tags were various even in the same group without significant differences between groups and lots of adhesive lateral branches were observed. 4. There were no statistically significant difference of SBS between AB2 and OS, but SBS of wet bonding groups were significantly higher(p<0.05) than dry bonding groups. 5. There were no consistent relationships between HLT and SBS.

• The Journal of Korea Assosiation for Disability and Oral Health
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• v.11 no.1
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• pp.1-4
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• 2015

Diastema is thought to be a problem related to aesthetics, pronunciation, or malocclusion. Due to its extent and patient conditions, orthodontic treatment, prosthodontic treatment, and conservative direct resin restoration are the treatment options for diastema closure. Additional factors need to be considered when deciding on the most appropriate treatment of diastema, particularly for patients with cerebral palsy. A 13-year-old girl visited the Department of Pediatric Dentistry at Yonsei University Dental Hospital with a chief complaint of the large gap between her upper front teeth. After clinical and radiographic examinations, midline diastema of 4.5 mm, protrusive maxilla incisors, congenital missing teeth, retained primary teeth, etc. were identified. Prosthodontic treatment with intentional root canal treatment was not appropriate because of the patient's age. Dental spaces can be closed effectively via orthodontic appliances. However, additional prosthodontic and restorative intervention is unavoidable, which incurs significant costs and requires more time. Instead of orthodontic and prosthodontic treatment, direct resin restoration can address the chief complaint; these restorations are reversible, less harmful to other oral structure and teeth, relatively easy to apply, less expensive than other treatments, and require shorter office visits. Midline diastema can be treated in several ways. For diastema closure in patients with cerebral palsy, conservative resin restorations are a short, simple, and appropriate treatment compared with orthodontic or prosthodontic treatments.