• Restorative Dentistry and Endodontics
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• v.30 no.5
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• pp.355-362
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• 2005

The purpose of this study was to compare the effect on marginal leakage of a resin surface sealant (Biscover) applied before or after polymerization of composite resin to unsealed composite restorations. Thirty Class V cavities with the occlusal margin in enamel and cervical margin in dentin or cementum were prepared on the buccal surfaces of sound extracted molars and restored with a microfilled light-cured composite resin (Micronew). Restorations were randomly assigned into one of three equal groups (n = 10): a control group - no surface sealing, group 1 - applied Biscover after polymerization of the composite resin. and group 2 - applied Biscover before polymerization of the composite resin. Specimens were thermocycled, immersed in a $20\%$ methylene blue solution for 4 hoots, sectioned longitudinally, and analyzed for leakage at the occlusal and gingival margins. The results of this study were as follows 1. In sealed group, group 2 showed higher microleakage than group 1 at both occlusal and gingival margins. but there was no significant difference between two groups (p > 0.05). 2. Unsealed control group showed a little higher microleakage than sealed group at occlusal margins, and a little Higher or similar microleakage than sealed group at gingival margins (p > 0.05) 3. Control group and group 2 showed significantly less microleakage at the occlusal margins, but group 1 showed no significantly difference between microleakage at the occlusal and gingival margins.

• Journal of the korean academy of Pediatric Dentistry
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• v.32 no.1
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• pp.13-17
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• 2005

Children and teenagers have a higher frequency of proximal surface caries in the posterior teeth than adults. For proximal restoration, class II amalgam or stainless steel crown has been widely used in the past, however composite resin restoration is getting ore popular due to it's superior cosmetic appearance. When applying composite resin on proximal area, various types of matrix bands can be utilized according to the operator's reference or skill. Such bands have several clinical effects including suitability for proximal margin, reduction of micro-leakage, moisture-control against saliva and ease finishing and polishing. In this case report, orthodontic bands were utilized instead of matrix bands as a remedy for proximal restorations in both primary and permanent teeth and their clinical advantages are as follows. 1. Orthodontic bands showed superior marginal adaptation compared to conventional matrix bands and moisture-control against saliva was excellent. 2. While applying composite resin, deformation of restoration material was estimated to be insignificant due to he rigidity of the orthodontic bands. 3. Natural tooth contour of the orthodontic bands facilitates to reproduce proximal tooth contour of the restoration. 4. In general, pediatric dentists are accustomed to applying orthodontic bands and this may allow pediatric dentists to make proximal composite restorations more efficiently than other dental specialists.

• Restorative Dentistry and Endodontics
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• v.26 no.2
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• pp.162-170
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• 2001

The purpose of this study was to investigate the effect of cavity configurations on the marginal leakage of class 5 glass ionomer cement and composite resin restorations. Four types of cavities such as saucer shape. notch shape. combined shape(notch shape occlusally and saucer shape gingivally). and U shape were prepared on the buccal and lingual surfaces of 80 extracted premolars(40 cavities for each shape). Occlusal cavity margins were placed at enamel and cervical margins were placed at dentin. 10 cavities of each shape were restored with Ketac Fil as a conventional glass ionomer cement. Fuji II LC improved as a resin modified glass ionomer cement, Z 100 as a hybrid composite resin. and Tetric Flow as a flowable composite resin (40 cavities for each material). After thermocycling, teeth were immersed in 5% basic fuchsin solution for 6 hours and sectioned longitudinally in a buccolingual direction through the center of the restoration. The dye penetrations at the tooth restoration interface were examined by stereomicroscope. The Result were as follows 1. In saucer shape, notch shape and combined shape, composite resin restorations showed lesser leakage than glass ionomer restorations(p<0.05) and in U shape. Tetric Flow showed the least marginal leakage and others were decreased as Z 100. Fuji II LC improved, Ketac Fil in that order. There were statistically significant difference between Tetric Flow and Fuji II LC improved. Ketac Fil and between Z 100 and Ketac Fil(p<0.05). 2. In Ketac Fil restoration group, saucer shape showed the highest marginal leakage and U shape showed the least marginal leakage and others were decreased as notch shape, combined shape in that order. There were statistically significant difference between saucer shape and combined shape, U shape and between notch shape and U shape(p<0.05). 3. In Fuji II LC improved restoration group, U shape showed the least marginal leakage. There were statistically significant difference between U shape and other three shapes(p<0.05). 4. The cavity configuration had no significant effect on marginal leakage of composite resin restorations(p>0.05).

• Restorative Dentistry and Endodontics
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• v.30 no.1
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• pp.22-30
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• 2005

The purpose of this study was to compare the effect of surface sealing materials on microleakage and surface roughness in Class V composite restorations. Twenty five standardized Class V cavity preparations were made on the facial surface of human premolars and were randomly assigned to 5 groups. The teeth were restored with Z-250 after applying Single Bond. Following 7 days storage in distilled water at $37^{\circ}C$, the restorations were sealed as following systems : No sealing ; Single Bond Adhesive ; Biscover ; Fortify ; Optiguard. Then, toothbrush abrasion test was conducted using a wear testing machine. Surface roughness was measured by means of profilometer before and after toothbrushing and the results were statistically analysed by using a paired t-test and ANOVA. The bonded interfaces and the changes of surface roughness were examined by SEM. For microleakage test, specimens were stained in a $2\%$ methylene blue solution, then longitudinally sectioned and analyzed for leakage at occlusal and cervical interfaces using stereomicroscope. The results were statistically analysed by using a Kruskal-Wallis and Mann-Whitney U test. Surface roughness was increasing in all groups after toothbrushing, but no statistically significant differences. In SEM observation, surface sealant was partially retained and partially detached in bonded interfaces. Especially, microgap was identified in cervical margins. In microleakage test, there was better seal in the enamel region and a significant difference between groups at occlusal margin. Control group and Single Bond group had significantly better marginal seal at enamel margin than cervical margin.

• Restorative Dentistry and Endodontics
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• v.34 no.5
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• pp.442-449
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• 2009

The aim of this study was to examine that thick dentin bonding agent application or low modulus composite restoration could reduce stresses on dentin bonding agent layer. A mandibular first premolar with abfraction lesion was modeled by finite element method. The lesion was restored by different composite resins with variable dentin bonding agent thickness ($50{\mu}m$, $100{\mu}m$, $150{\mu}m$). 170N of occlusal loading was applied buccally or lingually. Von Mises stress on dentin bonding agent layer were measured. When thickness of dentin bonding agent was increased von Mises stresses at dentin bonding agent were decreased in both composites. Lower elastic modulus composite restoration showed decreased von Mises stresses. On root dentin margin more stresses were generated than enamel margin. For occlusal stress relief at dentin boning agent layer to applicate thick dentin bonding agent or to choose low elastic modulus composite is recommended.

• Restorative Dentistry and Endodontics
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• v.34 no.6
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• pp.467-476
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• 2009

The aim of this study was to measure the dentinal tubular fluid flow (DFF) during and after amalgam and composite restorations. A newly designed fluid flow measurement instrument was made. A third molar cut at 3 mm apical from the CEJ was connected to the flow measuring device under a hydrostatic pressure of 15 $cmH_2O$. Class I cavity was prepared and restored with either amalgam (Copalite varnish and Bestaloy) or composite (Z-250 with ScotchBond MultiPurpose: MP, Single Bond 2: SB, Clearfil SE Bond: CE and Easy Bond: EB as bonding systems). The DFF was measured from the intact tooth state through restoration procedures to 30 minutes after restoration, and re-measured at 3 and 7days after restoration. Inward fluid flow (IF) during cavity preparation was followed by outward flow (OF) after preparation, In amalgam restoration, the OF changed to IF during amalgam filling and slight OF followed after finishing. In composite restoration, application CE and EB showed a continuous OF and air-dry increased rapidly the OF until light-curing, whereas in MP and SB, rinse and dry caused IF and OF, respectively. Application of hydrophobic bonding resin in MP and CE caused a decrease in flow rate or even slight IF. Light-curing of adhesive and composite showed an abrupt IF. There was no statistically significant difference in the reduction of DFF among the materials at 30 min. 3 and 7 days after restoration (p > 0.05).

• Journal of the korean academy of Pediatric Dentistry
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• v.27 no.2
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• pp.351-360
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• 2000

The purpose of this study was to evaluate the microleakage of class V compomers according to acid etching treatment and treatment times. Extracted 180 sound human molar teeth were selected then prepared physiologic pulpal pressure far this experiment. In this study class V cavities were prepared on buccal surface with gingival margin located in 1mm superior to CEJ under simulate physiological conditions. These specimens were randomly divided into 6 groups of 30 each and restored following methods : A: Dyract AP + Prime&Bond 2.1 Group 1 : No acid etching, according to manufacturer's instruction. Group 2 : 15 seconds acid etching and same method with Group 1. Group 3 : 30 seconds acid etching and same method with Group 1. B: F2000 groups + Single Bond adhesive Group 1 : No acid etching, according to manufacturer's instruction. Group 2 : 15 seconds acid etching and same method with Group 1 Group 3 : 30 seconds acid etching and same method with Group 1. After 500 thermocycling between $5^{\circ}C\;and\;55^{\circ}C$, the specimens were sealed with glass ionomer and nail varnish then placed in 5% methylene blue dye for 5 hours and rinsed with tab water. The specimens were embedded in orthodontic clear resin, then sectioned buccolingually through the center of restoration with a low speed diamond saw. The dye penetration on each of the specimens were then observed with a stereomicroscope at $\times20$ magnification. The results of this study were statistically analyzed using the indepedent sample t-test and analysis of variance. Results were as follows, 1. In occlusal walls, microleakage were significantly reduced in acid etched group restored with Dyract AP but no statistically significance in F2000 groups. 2. In gingival walls, microleakage were significantly reduced in group 2 restored with Dyract AP, and group 2 and group 3 in F2000 groups. 3. All groups, except group 3 in Dyract AP, showed significantly less microleakage in occlusal wall than gingival wall. 4. No statistical significance were showed between group 2 and group 3 in both materials.

• 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.296-303
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• 1998

The purpose of this study was to assess the effects of cavity designs on the marginal leakage of class 5 glass ionomer restorations. The five cavity designs were as follows ; notch shape(A group), notch shape with groove(B group), combined lesion(C group), combined lesion with groove and deep chamfer margin(D group) and combined lesion with groove and shoulder(E group), and each design had 10 cavities. After the cavities were restored with GIC, they were immersed in 0.5% basic fuchsin solution for 6 hours. The specimens were washed thoroughly and sectioned longitudinally in a buccolingual direction through the center of the restorations. The degree of marginal leakage was measured as the extent of dye penetration under the stereoscope. The results of this study were as follows 1. The enamel margins of all groups showed lesser leakage than dentin/cementum margins(p<0.05). 2. The combined lesion(C group) showed more leakage than notch shape(A group), but there was no siginificant difference(p>0.05). 3. In the notch shape, there was no influence on the marginal leakage by the groove preparation. 4. In the combined lesion, marginal leakage was decreased by the groove preparation and marginal modification.

• Journal of the korean academy of Pediatric Dentistry
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• v.31 no.4
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• pp.636-644
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• 2004

Recently, self-etching adhesive system have been developed and bonding procedures simplified into one or two steps, which are simultaneously applied to both enamel and dentin. These systems are easy to use and have the potential for good clinical success. The purpose of this study is to evaluate in vitro the microleakage on the cementum/dentin and enamel walls in composite resin restoration of Class V cavities, regarding the use of different adhesive systems. 30 human premolars were divided into 3 groups. A standardized Class V preparation was prepared on the buccal and lingual surface of each premolar. The preparation were made parallel to the cementoenamel junctions, with the gingival half of the preparation extending 1mm apical to the cementoenamel junction. After adhesive system was applied to teeth as manufacture's recommendation, hybrid resin composite was filled in bulk into the preparation and light polymerized according to manufacturer's recommendations. Specimen were stored in distilled water at $37^{\circ}C$ for 5 days and thermocycled 1000 times ($5^{\circ}C{\pm}2^{\circ}C\;and\;55^{\circ}C{\pm}2^{\circ}C)$, then immersed in a 2% methylene blue solution for 12 hours. After sectioning mesio distally through the restorations, the degree of dye penetration was scored under a stereomicroscope at ${\times}\;25$ magnification. The data were analyzed statistically using t-test and one-way ANOVA. The results were as follows: ${\cdot}$ There is no adhesive system which can prevent microleakage perfectly. ${\cdot}$ There is significant difference in microleakage between enamel margin and dentin margin (p<0.0001). ${\cdot}$ In enamel margin, self-etching primer systems did not show any significant difference comparing total-etching system. In denin margin, self-etching primer systems did not show any significant difference comparing one-bottle adhesive system used in combination with total-etching.