• Restorative Dentistry and Endodontics
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• v.20 no.1
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• pp.214-234
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• 1995

The purpose of this work was to study the compatibility of several commercially available dentin adhesives with composite resins. In this study, V-shaped cavity preparations were created on both buccal and lingual surfaces of 60 extracted human premolars($3mm{\times}3mm{\times}2mm$ deep). Preparations were located such that the occlusal margins were on the enamel and the gingival margins were on the cementum(1mm below the CEJ). These specimens were randomly divided into three equal groups. Three dentin adhesives(Scotchbond Multi-Purpose, All Bond 2, Prisma Universal Bond 3)were applied to the cavity in accordance with each manufacturer's instructions. The teeth in each group were restored with four composite resins(Silux plus, Z100, Bisfil, Prisma TPH) in three increments, with each increment light-cured for 40 seconds. All specimens were exposed to 500 cycles of thermal stress. Specimens then placed in a silver nitrate solution(50% by weight) and stored in darkness for 24 hours. They were then immersed for 6 hours in photographic developing solution under flourescent light. Specimens were sectioned buccolingually through the center of the restoration and observed under a binocular stereoscope. To compare the marginal leakage, ANOVA and Dunkan's multiple range tests were used in analysis. Selected samples were further studied using scanning electron microscopy(XL20, Philips, The Netherlands). The results were as follows. 1. In all groups, the enamel margin showed significantly less leakage than the cementum margin. 2. No statistically significant differences were found in microleakage when composite resins were used with their proprietary dentin adhesives. 3. In comparison between dentin adhesives, Prisma Universal Bond 3 showed significantly less leakage at the enamel margin and Scotch bond multi-purpose showed significantly less leakage at the cementum margin than the other groups. 4. In comparison between composite resins, Silux Plus showed significantly more leakage than other groups at the enamel margin and no statistically significant differences were found in microleakage at the cementum margin. 5. According to the backscattered scanning electron microscope, microleakage occurred via gaps at the dentin adhesives/dentin interface.

• The Journal of Advanced Prosthodontics
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• v.3 no.4
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• pp.186-189
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• 2011

PURPOSE. Porcelain fused to metal (PFM) crowns provide the best treatment option for teeth that have a large or defective restoration. More than 20% of teeth with PFM crowns or bridges require non-surgical root canal treatment (NSRCT). This may be due to the effect of restorative procedures and the possible leakage of bacteria and or their by-products, which leads to the demise of the tooth pulp. Thus, this study was planned to compare the ability of the restorative materials to seal perforated PFM specimens. MATERIALS AND METHODS. The study evaluates the ability of amalgam, composite or compomer restorative materials to close perforated PFM specimen's in-vitro. Ninety PFM specimens were constructed using Ni-Cr alloys and feldspathic porcelain, and then they were divided into 3 groups: amalgam (A), composite + Exite adhesive bond (B) and compomer + Syntac adhesive bond (C). All the PFM samples were embedded in an acrylic block to provide complete sealing of the hole from the bottom side. After the aging period, each group was further divided into 3 equal subgroups according to the thermocycling period (one week for 70 cycles, one month for 300 cycles and three months for 900 cycles). Each subgroup was put into containers containing dye (Pelikan INK), one maintained at $5^{\circ}C$ and the other at $55^{\circ}C$, each cycle for 30 sec time. The data obtained was analyzed by SPSS, 2006 using one way ANOVA test and student t-test and significant difference level at (P<.01). RESULTS. The depth of dye penetration was measured at the interfaces of PFM and filling materials using Co-ordinate Vernier Microscope. The lowest levels of the dye penetration for the three groups, as well as subgroups were during the first week. The values of dye leakage had significantly increased by time intervals in subgroups A and C. CONCLUSION. It was seen that amalgam showed higher leakage than composite while compomer showed the lowest level of leakage.

• Restorative Dentistry and Endodontics
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• v.26 no.2
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• pp.153-161
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• 2001

The purpose of this study was to evaluate microleakage of six current dentin bonding systems. In this in vitro study, class V cavities were prepared on buccal and lingual surfaces of thirty extracted human molars. Each margin was on enamel and dentin/cementum. Experimental teeth were randomly divided into six groups of 5 each. Group 1 : Scotchbond Multi-Purpose; Group 2 : Single Bond; Group 3 : Prime&Bond NT ; Group 4 : Clearfil Liner Bond 2 ; Group 5 : MAC Bond II ; Group 6 : One-up Bond F. The bonding agent and composite resin were applied to class V cavities according to manufacturer's directions. After thermocycling, the specimens were immersed in 0.5% basic fuchsin dye solution for 6 hours and sectioned longitudinally through the center of the restoration with a low speed diamond saw. The degree of microleakage was measured as the extent of dye penetration under the stereomicroscope at $\times$20. The data were analyzed using one way ANOVA. When significant differences found. multiple comparisons were made using Duncan's Multiple Range Test. The results of this study were as follows: 1. In all groups, leakage value seen at the enamel margin was significantly lower than that seen at the dentin margin(P<0.001). 2. At the enamel margin, none of the dentin bonding systems used in this study showed statistically significant difference in leakage values(P<0.05). 3. At the cementum margin, group 3 showed the highest leakage value, and others were decreased as group 5, 6, 4 in that order, and group 1, 2 showed the lowest leakage value. There was statistically significant difference between group 3 and the other groups except for group 5(P<0.05).

• Restorative Dentistry and Endodontics
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• v.26 no.4
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• pp.263-272
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• 2001

The aim of this study was to investigate the influence of four different light curing modes on the marginal leakage of Class V composite resin restoration. Eighty extracted human premolars were used. Wedge-shaped class Y cavities were prepared on the buccal surface of the tooth with high-speed diamond bur without bevel. The cavities were positioned half of the cavity above and half beyond the cemento-enamel junction. The depth, height, and width of the cavity were 2 mm, 3 mm and 2 mm respectively. The specimens were divided into 4 groups of 20 teeth each. All the specimen cavities were treated with Prime & Bond$^{R}$ NT dental adhesive system (Dentsply DeTrey GmbH, Germany) according to the manufacturer's instructions and cured for 10 seconds except group VI which were cured for 3 seconds. All the cavities were restored with resin composite Spectrum$^{TM}$ TPH A2 (Dentsply DeTrey GmbH, Germany) in a bulk. Resin composites were light-cured under 4 different modes. A regular intensity group (600 mW/${cm}^2$, group I) was irradiated for 30 s, a low intensity group (300 mW/${cm}^2$, group II) for 60 s and a ultra-high intensity group (1930 mW/${cm}^2$, group IV) for 3 s. A pulse-delay group (group III) was irradiated with 400 mW/${cm}^2$ for 2 s followed by 800 mW/${cm}^2$ for 10 s after 5 minutes delay. The Spectrum$^{TM}$ 800 (Dentsply DeTrey GmbH, Germany) light-curing units were used for groups I, II and III and Apollo 95E (DMD, U.S.A.) was used for group IV. The composite resin specimens were finished and polished immediately after light curing except group III which were finished and polished during delaying time. Specimens were stored in a physiologic saline solution at 37$^{\circ}C$ for 24 hours. After thermocycling (500$\times$, 5-55$^{\circ}C$), all teeth were covered with nail varnish up to 0.5 mm from the margins of the restorations, immersed in 37$^{\circ}C$, 2% methylene blue solution for 24 hours, and rinsed with tap water for 24 hours. After embedding in clear resin, the specimens were sectioned with a water-cooled diamond saw (Isomet$^{TM}$, Buehler Co., Lake Bluff, IL, U.S.A.) along the longitudinal axis of the tooth so as to pass the center of the restorations. The cut surfaces were examined under a stereomicroscope (SZ-PT Olympus, Japan) at ${\times}$25 magnification, and the images were captured with a CCD camera (GP-KR222, Panasonic, Japan) and stored in a computer with Studio Grabber program. Dye penetration depth at the restoration/dentin and the restoration/enamel interfaces was measured as a rate of the entire depth of the restoration using a software (Scion image, Scion Corp., U.S.A.) The data were analysed statistically using One-way ANOVA and Tukey's method. The results were as follows : 1. Pulse-Delay group did not show any significant difference in dye penetration rate from other groups at enamel and dentin margins (p>0.05) 2. At dentin margin, ultra-high intensity group showed significantly higher dye penetration rate than both regular intensity group and low intensity group (p<0.05). 3. At enamel margin, there were no statistically significant difference among four groups (p>0.05). 4. Dentin margin showed significantly higher dye penetration rate than enamel margin in all groups (p<0.05).

• Journal of the korean academy of Pediatric Dentistry
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• v.23 no.4
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• pp.800-817
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• 1996

In this study, we tried to evaluate the effect of Amalgambond liner application on the degree of marginal leakage and retention of amalgam restoration by comparing with that of the Copalite and All-bond 2. The results obtained from this experiment were as follows; 1. Tensile strength representing the bond between amalgam and tooth structure was the highest in Amalgambond, and All-Bond 2, Copalite in descending order. There were statistically significant difference between each group(P<0.05). 2. The degree of microleakage in Amalgambond was lower than that of All-Bond 2, and Copalite, but no stastically significant difference could be found (P>0.05). 3. The liner such as Amalgambond or All-Bond 2 were evaluated to be superior to the conventional Copalite in bond strength as well as in microleakage. But the result of this study could not show the superiority of one material over the others; Amalgambond and All-bond 2. Besides the results of the study, other factors, such as practical convenience, should be considered in determining the selection of material. The support of welldesigned clinical studies on this subject are in demand.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.16 no.1
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• pp.83-97
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• 2013

This study was carried out to suggest an experimental base in selecting the drought resistance of plants. Adopting the natural drought method, this paper studies the drought resistance of 12 kinds of ground cover plants. focusing on analyzing the changes of relative water content on leaf, relative electric conductivity and chlorophyll content in 12 kinds of plants, and and the relation between soil water content under drought stress. The drought resistance of the plants were subject to laboratory and rooftop drought resistance treatments. The Logistic model of nonlinear regression analysis was used to evaluate the lethal time that were predicted with the range of 10.4~30.1d on roof top, and 19.5~39.0d on hothouse. The result shows that with the increase of stress time, relative water content and chlorophyll content on leaf were in a downward trend; the relative electric conductivity was upward tendency. Among 12 species of ground cover plants, exclude Pulsatilla koreana, Ainsliaea acerifolia were selected for rooftop plants because they showed resist drought strongly and took adaptive ability.

• Restorative Dentistry and Endodontics
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• v.26 no.6
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• pp.492-498
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• 2001

The purpose of this study was to evaluate four different composite resins in vitro for microleakage in Class II box type restorations that have gingival margins apical to the cementoenamel junction. Forty caries free extracted human molars were used in this study. The Class II cavities were prepared 1.0mm below cementoenamel junction with a #701 carbide bur. The teeth were randomly divided into four groups, each group comprising 20 treated cavities according to adhesives and filling materials ; Group 1: Scotchbond Multipurpose/Z 100. Group 2: Ariston Liner/Ariston pHc, Group 3: One Step/Pyramid, Group 4: Prime & Bond NT/SureFil. To simulate the clinical situation during restoration placement, a restoration template was fabricated and composite resin was filled using a three sited light-curing incremental technique. The specimens were stored in the 100% humidity for 7 days prior to thermocycling. The specimens were immersed in 2% methylene blue dye solution for 24 hours and then embeded in transparent acrylic resin and sectioned mesiodistally with a diamond wheel saw. The degree of marginal leakage was scored under the stereomicroscope($\times$20) and the data were analyzed by Kruskal Wallis test and Mann Whitney test. (omitted)

• Restorative Dentistry and Endodontics
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• v.23 no.1
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• pp.269-277
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• 1998

This in vitro study compared the microleakage of 4 lining conditions when used with Gallium alloy GF II and Valiant PhD. Class V cavity was prepared on both buccal and lingual surface of 80 extracted human premolar & molar teeth with one margin in enamel and another in dentin. Before restoration, prepared cavities were applied to no-liner, cavity varnish, Scotchbond multipurpose, and Superbond D-liner II plus according to manufacture's instructions. The restored teeth were stored in saline for 1 week, then thermocycled for 100 times, stained with 0.5% basic fuchsin dye for 1 day, sectioned, and observed using a light microscope. Following results were obtained. 1. The leakage value of Superbond-lined group showed significantly lower than that of nolined group on both margins of Valiant PhD(p<0.05). 2; There was no significant difference between the 4 lining conditions in Gallium alloy GF II (p>0.05). 3. When We make a comparison between Gallium alloy GF II and Valiant PhD under same lining conditions, the microleakage value of Gallium alloy GF II showed lower than that of Valiant PhD on occlusal & gingival margin(p<0.05) except for Superbond-lined group(p>0.05).

• Journal of the Korean Orthopaedic Association
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• v.54 no.1
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• pp.24-29
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• 2019

Purpose: To evaluate the characteristics and the risk factors of early onset subsequent vertebral compression fractures after percutaneous vertebroplasty. Materials and Methods: A total of 44 patients, who had a new subsequent vertebral fracture after percutaneous vertebroplasty for an osteoporotic vertebral compression fracture between January 2013 and December 2015, were recruited. The patients were divided into two groups according to the onset period of subsequent fracture. The number of patients who had a fracture within 3 months following vertebroplasty were 22 cases (Group A); after 3 months were 22 cases (Group B). Variables, including age, sex, bone mineral density (BMD), body mass index (BMI), preexisting vertebral compression fracture, location of the initial fracture, intradiscal cement leakage, injected cement volume, restoration of vertebral body height, and correction of kyphosis, in the two groups were analyzed and compared retrospectively. Results: The age, sex, BMD, BMI, preexisting vertebral compression fracture, location of the initial fracture, intradiscal cement leakage, and correction of kyphosis were similar in the two groups. Both a greater volume of bone cement injected and a greater degree of vertebral height restoration contributed significantly to the risk of fracture within 3 months. Conclusion: The cement volume and degree of height restoration are risk factors for early onset fracture at the adjacent vertebrae after percutaneous vertebroplasty and close attention is needed during the follow-up period.

• 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.