• 대한소아치과학회지
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• 제28권1호
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• pp.54-66
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• 2001

기존의 불소방출 복합레진보다 많은 양의 불소를 방출시키기 위해 총 복합레진 중 불소의 함량이 각각 8, 16, 24wt%가 되도록 $SrF_2$계 충진재를 첨가하여 3종의 수복용 불소방출 복합레진 시험군(VF8, VF16, VF24)을 제조하고 이에 대한 물리적 성질과 세포독성 및 불소방출량을 기존의 복합레진 제품인 Heliomolar(HE), Veridonfil(VE), Z100(ZH), Aelitefil(AE) 등의 대조군과 비교 시험하여 다음과 같은 결과를 얻었다. 1. 시험군의 3점 굽힘강도는 ZH에 비해서는 낮았으나, 다른 대조군인 AE, VE와 비슷하였고, HE보다는 우수하였으며, 시험군 간의 유의차는 없었다(p<0.05). 2. 시험군의 표면경도는 ZH보다 낮았고, AE, VE와 유사하였으며, 불소 방출 대조군인 HE보다는 높았다(p<0.05). 시험군 중에서는 VF16, VF24가 VF8에 비해 표면경도가 높았다(p<0.05). 3. 시험군의 마모도는 대조군인 HE, ZH보다 낮았으며, 시험군 중에서는 VF16, VF24가 VF8에 비해 낮은 마모도를 나타내었다(p<0.05). 4. 시험군의 물흡수도는 대조군인 HE, VE, AE와 유사하였으며 ZH보다는 낮았다(p<0.05). 시험군의 용해도는 대조군인 HE와 유의차가 없었으며, VE, ZH, AE보다 높은 용해도를 나타내었다(p<0.05). 5. 시험군은 대조군인 HE보다 $9\sim23$배 많은 양의 불소를 방출하였으며, 시험군의 불소방출량은 $SrF_2$계 충진재의 함유량과 비례하였다. 6. 시험군과 대조군은 모두 약한 정도의 세포독성을 나타내었다. 이상의 실험결과에서 $SrF_2$계 충진재를 첨가한 불소방출 복합레진 시험군의 물리적 성질과 세포독성은 기존의 복합레진과 유사한 것으로 나타났으며, 불소방출량은 기존의 불소방출 복합레진보다 현저히 높아 이차우식증에 대한 항우식효과도 높을 것으로 사료되었다.

• The Journal of Advanced Prosthodontics
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• 제5권4호
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• pp.479-484
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• 2013

PURPOSE. The aim of this study was to evaluate the effects of additional acid etching and curing mechanism (light-curing or self-curing) of a composite resin on the dentin bond strength and compatibility of one-step self-etching adhesives. MATERIALS AND METHODS. Sixteen human permanent molars were randomly divided into eight groups according to the adhesives used (All-Bond Universal: ABU, Clearfil S3 Bond: CS3), additional acid etching (additional acid etching performed: EO, no additional acid etching performed: EX), and composite resins (Filtek Z-250: Z250, Clearfil FII New Bond: CFNB). Group 1: ABU-EO-Z250, Group 2: ABU-EO-CFNB, Group 3: ABU-EX-Z250, Group 4: ABU-EX-CFNB, Group 5: CS3-EO-Z250, Group 6: CS3-EO-CFNB, Group 7: CS3-EX-Z250, Group 8: CS3-EX-CFNB. After bonding procedures, composite resins were built up on dentin surfaces. After 24-hour water storage, the teeth were sectioned to make 10 specimens for each group. The microtensile bond strength test was performed using a microtensile testing machine. The failure mode of the fractured specimens was examined by means of an optical microscope at ${\times}20$ magnification. The data was analyzed using a one-way ANOVA and Scheffe's post-hoc test (${\alpha}$=.05). RESULTS. Additional etching groups showed significantly higher values than the no additional etching group when using All-Bond Universal. The light-cured composite resin groups showed significantly higher values than the self-cured composite resin groups in the Clearfil S3 Bond. CONCLUSION. The additional acid etching is beneficial for the dentin bond strength when using low acidic one-step self-etch adhesives, and low acidic one-step self-etch adhesives are compatible with self-cured composite resin. The acidity of the one-step self-etch adhesives is an influencing factor in terms of the dentin bonding strength and incompatibility with a self-cured composite resin.

• 대한치과보존학회:학술대회논문집
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• 대한치과보존학회 2003년도 제120회 추계학술대회 제 5차 한ㆍ일 치과보존학회 공동학술대회
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• pp.610-610
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• 2003

The purpose of this study was to propose a new dental color system through color evaluation of generally used dental composite and porcelain. In this study, Vita Omega 900 dental porcelain and 10 kinds of composite resins were used. A disk specimens(15mm diameter, 4mm thickness) of each material/shade combination were made. Resin compasite was condensed into Teflon mold and pressed between glass plates to flatten the surface. Pressed compasite was polymerized using an Optilux 501(Demetron, USA) for 200 seconds of each side.(중략)

• The Journal of Advanced Prosthodontics
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• 제12권6호
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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.

• 한국치위생학회지
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• 제21권1호
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• pp.89-98
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• 2021

Objectives: The purpose of this study was to investigate the perception and satisfaction of caregivers and parents after being covered by health insurance for light-curing composite resin fillings, and to contribute to the settlement of the expansion and coverage of health insurance. Methods: A survey was conducted on caregivers who visited two dental institutions in the Gyeonggi-do area, and parents who joined internet cafes (online communities) in the Gyeonggi-do area from June 2 to September 2, 2020. 225 responses were collected eventually, and 212 valid responses were used as analysis data. Results: 67.0% of the study subjects were aware of the permanent teeth resin fillings being covered by health insurance and the satisfaction was relatively high (91.5%). There was a statistically significant difference in the perception of permanent tooth resin filling benefits according to the child's oral condition (p=0.025) and the parents' own interest in oral health (p=0.039). Conclusions: Based on the results of this study, it is necessary to increase the accessibility to the initial treatment for dental care of children through active promotion of detailed items of permanent teeth resin fillings.

• Restorative Dentistry and Endodontics
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• 제15권2호
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• pp.17-33
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• 1990

The purpose of this study was to evaluate the fracture toughness of dental composite resins and to investigate the filler factor affecting the fracture behaviour on which the degree of fracture toughness depends. Six kinds of commercially available composite resin;, including two of each macrofilled, microfilled, and hybrid type were used for this study, The plane strain fracture toughness ($K_{10}$) was determined by three-point bending test using the single edge notch specimen according to the ASTM-E399. The specimens were fabricated with visible light curing or self curing of each composite resin previously inserted into a metal mold, and three-point bending test was conducted with cross-head speed of 0.1mm/min following a day's storage of the specimens in $37^{\circ}C$ distilled water. The filler volume fractions were determined by the standard ashing test according to the ISO-4049. Acoustic Emission(AE), a nondestructive testing method detecting the elastic wave released from the localized sources In material under a certain stress, was detected during three-point bending test and its analyzed data was compared with, canning electron fractographs of each specimen. The results were as follows : 1. The filler content of composite resin material was found to be highest in the hybrid type followed by the macrofilled type, and the microfilled type. 2. It was found that the value of plane strain fracture toughness of composite resin material was in the range from 0.69 MPa$\sqrt{m}$ to 1 46 MPa$\sqrt{m}$ and highest In the macrofilled type followed by the hybrid type, and the microfilled type. 3. The consequence of Acoustic Emission analysis revealed that the plane strain fracture toughness increased according as the count of Acoustic Emission events increased. 4. The higher the plane strain fracture toughness became, the higher degree of surface roughness and irregularity the fractographs demonstrated.

• Restorative Dentistry and Endodontics
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• 제46권4호
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• pp.51.1-51.13
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• 2021

Objectives: This study aimed to evaluate the effect of improper positioning single-peak and multi-peak lights on color change, microhardness of bottom and top, and surface topography of bulk fill and incremental composites after artificial aging for 1 year. Materials and Methods: Bulk fill and incremental composites were cured using multi-peak and single-peak light-emitting diode (LED) following 4 clinical conditions: (1) optimal condition (no angulation or tip displacement), (2) tip-displacement (2 mm), (3) slight tip angulation (α = 20°) and (4) moderate tip angulation (α = 35°). After 1-year of water aging, the specimens were analyzed for color changes (ΔE), Vickers hardness, surface topography (Ra, Rt, and Rv), and scanning electron microscopy. Results: For samples cured by single-peak LED, the improper positioning significantly increases the color change compared to the optimal position regardless of the type of composite (p < 0.001). For multi-peak LED, the type of resin composite and the curing condition displayed a significant effect on ΔE (p < 0.001). For both LEDs, the Vickers hardness and bottom/top ratio of Vickers hardness were affected by the type of composite and the curing condition (p < 0.01). Conclusions: The bulk fill composite presented greater resistance to wear, higher color stability, and better microhardness than the incremental composite when subjected to improper curing. The multi-peak LED improves curing under improper conditions compared to single-peak LED. Prevention of errors when curing composites requires the attention of all personnel involved in the patient's care once the clinical relevance of the appropriate polymerization reflects on reliable long-term outcomes.

• Restorative Dentistry and Endodontics
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• 제43권1호
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• pp.13.1-13.7
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• 2018

Dental erosion is frequently overlooked in clinical practice. The management of erosion-induced damage to the dentition is often delayed, such that extensive occlusal rehabilitation is required. These cases can be diagnosed by a careful clinical examination and a thorough review of the patient's medical history and/or lifestyle habits. This case report presents the diagnosis, categorization, and management of a case of gastro-esophageal reflux disease-induced palatal erosion of the maxillary teeth. The early management of such cases is of utmost importance to delay or prevent the progression of damage both to the dentition and to occlusal stability. Non-invasive adhesively bonded restorations aid in achieving this goal.

• 대한치과의사협회지
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• 제23권12호통권199호
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• pp.1031-1037
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• 1985

The purpose of this study was to evaluate the marginal sealing ability of 'vivadent.' Using freshly extracted human teeth and 2% aqueous methylene blue, the marginal leakage of dye in restorative materials such as vivadent with acid etching technique, Durafill with acid etching technique, silar with acid etching technique, Adaptic, and Amalgam were investigated at 37℃ and under temperature cycling in range of 4℃-60℃. The results were as follows; 1. All filling materials showed some degree of marginal penetration by 2% methylene blue dye. 2. Vivadent with acid etching technique revealed effective marginal sealing ability, but under temperature cycling it showed increased marginal leakage. 3. All resins showed greater marginal leakage than amalgam restoration. 4. Vivadent had the most effective marginal sealing ability in experimented resins.

• Restorative Dentistry and Endodontics
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• 제43권2호
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• pp.26.1-26.12
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• 2018

Objective: The purpose of this study was to investigate the degree of conversion (DC) and mechanical properties of a microhybrid Filtek Z250 (3M ESPE) resin composite after aging. Method: The specimens were fabricated using circular molds to investigate Vickers microhardness (Vickers hardness number [VHN]) and DC, and were prepared according to ISO 4049 for flexural strength testing. The initial DC (%) of discs was recorded using attenuated total reflectance-Fourier transforming infrared spectroscopy. The initial VHN of the specimens was measured using a microhardness tester under a load of 300 g for 15 seconds and the flexural strength test was carried out with a universal testing machine (crosshead speed, 0.5 mm/min). The specimens were then subjected to thermocycling in $5^{\circ}C$ and $55^{\circ}C$ water baths. Properties were assessed after 1,000-10,000 cycles of thermocycling. The surfaces were evaluated using scanning electron microscopy (SEM). Data were analyzed using 1-way analysis of variance followed by the Tukey honest significant difference post hoc test. Results: Statistical analysis showed that DC tended to increase up to 4,000 cycles, with no significant changes. VHN and flexural strength values significantly decreased upon thermal cycling when compared to baseline (p < 0.05). However, there was no significant difference between initial and post-thermocycling VHN results at 1,000 cycles. SEM images after aging showed deteriorative changes in the resin composite surfaces. Conclusions: The Z250 microhybrid resin composite showed reduced surface microhardness and flexural strength and increased DC after thermocycling.