• Restorative Dentistry and Endodontics
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• v.25 no.1
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• pp.56-62
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• 2000

The purpose of this study was to assess the effects of restorative materials on the marginal leakage of wedge-shaped class V cavity. The study was performed in vitro in 25 defect-free permanent, extracted teeth. Wedge-shaped class V cavities were prepared and then the teeth were randomly selected and restored according to the following. Group A : restoration with Tetric Ceram(composite resin) Group B : restoration with Tetric flow(flowable resin) Group C : restoration with Compoglass after acid etching(compomer) Group D : restoration with Compoglass(compomer) Group E : restoration with Fuji II LC improved(resin-modified GIC) After thermocycling, the specimens were immersed in 5% basic fuchsin solution for 6 hours and sectioned longitudinally through the center of the restoration. The degree of marginal leakage was measured as the extent of dye penetration under the stereomicroscope. The data were analysed using one-way ANOVA. When significant differences found, multiple comparisons were made using Duncan's Multiple Range Test. The results were as follows: 1. The occlusal margins of all groups except for Fuji II LC improved showed lesser leakage than gingival margins and there was statistically significant difference(p<0.05). 2. At the occlusal margins, group A, B showed same marginal leakage scores, and others were decreased as group C, D, E in that order. There were statistically significant difference between group A, Band group D, E, group C and group E(p<0.05). 3. At the gingival margins, group B, C showed same marginal leakage scores, and others were decreased as group A, D, E in that order. But there was statistically significant difference between group B, C and group E(p<0.05). 4. In the Compoglass restoration, acid-etching technique was beneficial for marginal sealing ability at all of margins. But there was no statistically significant difference (p>0.05). In the restorations for wedge-shaped class V cavities, resin restoration with acid etching technique is recommended.

• 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.31 no.4
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• pp.282-289
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• 2006

The purpose of this study was to compare the ability of three resin surface sealants to prevent microleakage in Class V composite resin restorations. Forty Class V cavities with the occlusal margin in enamel and gingival margin in dentin were prepared on the buccal surfaces of sound extracted molars, and restored with composite resin. Restorations were randomly assigned into one of four equal groups (n = 10): a control group, without resin sealing, and three experimental groups in which margins were sealed with Fortify Plus, Biscover and Permaseal, respectively. Specimens were thermocycled, immersed in a 2% methylene blue solution for 4 hours, sectioned longitudinally, and observed the leakage at the occlusal and gingival margins. The result was analyzed using Kruskal-Wallis test, Mann-Whitney test and Wilcoxon signed rank test. In conclusion, the ability to reduce microleakage at occlusal margins was similar in all of three sealants. However at gingival margin, it depended on the type of used resin surface sealant. At gingival margin. control and Fortify Plus group showed statistically higher microleakage than PermaSeal group. and Fortify Plus group also showed higher microleakage than BisCover group (p < 0.05).

• Restorative Dentistry and Endodontics
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• v.33 no.6
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• pp.570-579
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• 2008

The purpose of this study was to investigate the distribution of tensile stress of canal obturated maxillary second premolar with access cavity and notch-shaped class V cavity restored with composite resin using a 3D finite element analysis. The tested groups were classified as 8 situations by only access cavity or access cavity with notch-shaped class V cavity (S or N), loading condition (L1 or L2), and with or without glass ionomer cement base (R1 or R2). A static load of 500 N was applied at buccal and palatal cusps. Notch-shaped cavity and access cavity were filled microhybrid composite resin (Z100) with or without GIC base (Fuji II LC). The tensile stresses presented in the buccal cervical area, palatal cervical area and occlusal surface were analyzed using ANSYS. Tensile stress distributions were similar regardless of base. When the load was applied on the buccal cusp, excessive high tensile stress was concentrated around the loading point and along the central groove of occlusal surface. The tensile stress values of the tooth with class Ⅴ cavity were slightly higher than that of the tooth without class V cavity. When the load was applied the palatal cusp, excessive high tensile stress was concentrated around the loading point and along the central groove of occlusal surface. The tensile stress values of the tooth without class V cavity were slightly higher than that of the tooth with class V cavity.

• Proceedings of the KACD Conference
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• 2003.11a
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• pp.572-572
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• 2003

There were attempts to reduce the micro leakage and surface roughness of resin composite. One of them is surface sealing. The purpose of this study was to compare the effect of materials, specifically developed for surface sealing, on microleakage and surface roughness in Class V composite restorations. Twenty five standardized Class V cavity preparations were made on the facial surface of extracted human premolars and were randomly assigned to 5 groups. The teeth were restored with Z-250 resin composite after applying Single Bond adhesive system.(중략)

• Restorative Dentistry and Endodontics
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• v.27 no.3
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• pp.257-269
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• 2002

Objective : The purpose of this study was to evaluate the resin infiltration into dentin of one-bottle adhesive systems and self-etching primer bonded to Class V cavities using confocal laser scanning microscope(CLSM). Material and Methods : Forty Class V cavities were prepared from freshly extracted caries-free Human teeth. These teeth were divided into two groups based on the presence of cervical abrasion: Group I, cervical abrasion : Group II, wedge-shaped cavity preparation. Resin-dentin interfaces were produced with two one-bottle dentin bonding systems-ONE COAT BOND(OCB; Coltene$^R$) and Syntac$^R$SPrint$^{TM}$(SS; VIVADENT)-, one self-etching priming system-CLEARFIL$^{TM}$ SE BOND (SB : KURARAY)- and one multi-step dentin bonding system-Scotchbond$^{TM}$Multi-Purpose (SBMP, 3M Dental Products)-as control according to manufacturers' instructions. Cavities were restored with Spectrum$^{R}$(Dentsply). Specimens were immersed in saline for 24 hours and sectioned longitudinally with a low-speed diamond disc. The resin-dentin interfaces were microscopically observed using CLSM. The quality of resin-infiltrated dentin layers were evaluated by five dentists using 0~4 scale. Results : Confocal laser scanning microscopal investigations using primer labeled with rhodamine B showed that the penetration of the primer occurred along the cavity margins. Statistical analysis using one-way ANOVA followed by Duncan's Multiple Range test revealed that the primer penetration of the group 2(wedge-shaped cavity preparation) was more effective than group 1(cervical abrasion) and that of the gingival interfaces was more effective than the occlusal interfaces. In the one-bottle dentin bonding systems, the resin penetration score of OCB was compatible to SBMP, but those of SS and self-etching priming system, SB were lower than SBMP.

• Restorative Dentistry and Endodontics
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• v.18 no.1
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• pp.103-113
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• 1993

The purpose of this study was to evaluate the tensile bond strength of composite resin inlays according to the their internal surface treatment and types of luting cement and compared them with the conventional direct resin filling thchnique. Class II cavities were prepared in 50 extracted human molar teeth, and then equally divided into five groups. Group 1 : Cavities of control group were directly filled with P-50. Group 2 : Cavities of resin inlay group were luted with resin cement. Group 3 : Cavities of resin inlay group were luted with luting G-I cement. Group 4 : Cavities of resin inlay group were luted with resin cement after sandblasting. Group 5 : Cavities of resin inlay group were luted with luting G-I cement after sandblasting. All specimens were polished with same method and stored in normal saline for 24 hours before testing. An Universal Testing machine(Model No. AGS-100A, Shimadzu, Japan) was used to apply tensile loads in the vertical direction, and the force required for separation was recorded with a cross-head speed of 5mm/min and 100kg in full scale. The results were as follows : 1. The mean tensile bond strength was lowest in group luted with luting G-I cement, with measurements of $14.45{\pm}0.78(kg/cm^2)$ and highest in group luted with resin cement after sandblasting, with measurements of $49.6{\pm}2.74(kg/cm^2)$. 2. The tensile bond strength was greater in resin inlay groups luted with resin cement than in control group and resin inlay groups luted with luting G-I cement(P<0.05). 3. The tensile bond strength was lower in resin inlay groups luted with luting G-I cement than in control group(P<0.05). 4. The tensile bond strength was greater in resin inlay groups luted with resin cement or luting G-I cement after sandblasting than without that(P<0.05).

• Restorative Dentistry and Endodontics
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• v.18 no.2
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• pp.413-422
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• 1993

The purpose of this study was to evaluate the adaptation of light cured glass ionomer cement and composite resin using all- etch technique to tooth structure. In this study, class V cavities were prepared on the buccal surfaces of 10 extracted human premolar teeth with cementum margin and teeth were randomly assigned 2 groups of 5 teeth each. The cavities of glass ionomer cement group were filled with the light cured glass ionomer cement(Fuji II LC) and the cavities of composite resin group were filled with the light cured composite resion(P - 50) using all- etch technique with All- Bond 2. The restored teeth were stored in 100 % relative humidity at $37^{\circ}C$ for 48 hours. And then, the roots of the teeth were removed with the tapered fissure bur and the remaining crowns were sectioned occlusogingivally through the center of restorations. Adaptation at tooth - restoration interface were assessed occlusally, gingivally, and axially by scanning electron microscope. The results were as follows : 1. The adaptation to enamel walls of composite resin restorations using All - Bond 2 showed better than glass ionomer restorations. 2. The adaptation to gingival and axial walls of glass ionomer restorations showed better than composite resin restorations using All - Bond 2. 3. In both groups, occlusal margins of restorations showed better adaptation than gingival margins of restorations.

• Journal of the Korean Wood Science and Technology
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• v.16 no.1
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• pp.3-8
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• 1988

This study was carried out to examine the effect of pretreatment of veneer with aluminum sulfate solution for the manufacture of the kapur plywood on the reduction of urea resin spread. The results were as follows: 1. Specific gravities of plywoods made of the kapur veneers ranged from 0.83 to 0.84 and their moisture contents based on air dry weight showed from 10.6% to 11.4%. These met the Korean Industrial Standards. 2. In the case of dry shear strength for the 3rd class plywood, 40% reduction- spread met K S as well as normal urea resin spread. pH of the aluminum sulfate solution gave better result at pH 4.5 and pH 6 than at pH 3. For the manufacture of the 2nd class plywood, hot and cold water-wet shear strength show the best results at the following conditions; such as 20% reduction spread, pH 4.5 of aluminum sulfate solution and all veneer treatment.

• Restorative Dentistry and Endodontics
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• v.26 no.1
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• pp.16-22
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• 2001

The purpose of this study was to evaluate the marginal microleakage of condensable composite resin restorations according to flowable resin lining of internal cavity wall. The eighty extracted human molar teeth without caries and/or restorations are used The experimental teeth were randomly assigned into four groups of ten teeth each. Eighty caries-free extracted human molars were used in this study. The conventional class II cavities (box-shaped on mesial and distal surface, faciolingual width : 3mm, gingival wall depth : 1.5mm) were prepared 1mm below cementoenamel junction with a # 701 carbide bur. The teeth were divided into four groups, and then each group were subdivided into A & B group according to flowable resin & compomer lining ; Group 1-A : Tetric Ceram filling, Group 1-B : Tetric Flow lining and Tetric Ceram filling, Group 2-A Ariston pHc filling, Group 2-B : Tetric Flow lining and Ariston pHc filing, Group 3-A SureFil filling, Group 3-B : Dyract Flow lining and SureFil filling, Group 4-A : Pyramid filling, Group 4-B : Aeliteflo lining and Pyramid filling. To simulate as closely as possible the clinical situation during retoration placement, a "restoration template" was fabricated, and the condensable resin was filled using a three-sited light-curing incremental technique. All the materials used were applied according to the manufacturers' instructions. The specimens were stored in the 100% humidity for 7 days prior to thermocycling (100 thermal cycles of 5~55$^{\circ}C$ water with a 30-second dwell time) The specimens were immersed in 2% metyleneblue dye for 24 hours, and then embedded in transparent acrylic resin and sectioned mesiodistally with diamond wheel saw. The degree of marginal leakage was scored under stereomicroscope ($\times$20) and the data were analyzed by Kruskal-Wallis test and Wilcoxon signed ranks test. The results were as follows : 1. In the gingival margins of all the group, microleakage of subgroup B was less than subgroup A. 2. In the group 1, 2, 4, there was significant differences between subgroup A and B (p<0.05), but in the group 3, there was not significant different between group 3-A (SureFil) and group 3-B (Dyract flow/SureFil) (p>0.05). 3. In the subgroup A and B, there was significant different between all group except group 4 of subgroup A. From the results above, it was suggested that the cavity lining of flowable resin and flowable compomer in condensable resin restoration decrease microleakage at gingival margin, and does improve their ability to seal the gingival margin of class II preparation.