• Restorative Dentistry and Endodontics
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• v.15 no.1
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• pp.97-105
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• 1990

When conventional root canal treatment is failed or contraindicated, retrograde root canal filling following apicoectomy is a valuable procedure, aimed at hermetically sealing the root canal against leakage of irritants from the canal into the periapical tissue. In this in vitro investigation, to analyze apical microleakage electrochemically in teeth with different retrograde filling materials and preparation types, single - rooted tooth was cut 2mm from the apex and each Class I and Slot preparation was prepared. Experimental groups : Group 1. Amalgam filling with cavity varnish in Class I preparation Group 2. Scotchbond 2+Silux filling in Class I preparation Group 3. Gutta percha filling with ZOE cement in Class I preparation Group 4. Amalgam filling with cavity varnish in Slot preparation Group 5. Scotchbond 2+Silux filling in Slot preparation Each specimens was immersed in 1% solution of KCl, and applied a potential of 9V external power supply. Measurements of the current flow were obtained at 1, 2, 3, 7, 9, 12, 14, 18, 21, 25 and 28 day after immerson. Marginal microleakage were compared and evaluated. The results were as follows ; 1. The group filled with composite resin with dentin bonding agent shows lower apical microleakage value than the group filled with amalgam following varnish application (P<0.01). 2. In the group filled with gutta percha, apical microleakage value was the hightest 3. There was no significant difference between Class I cavity and Slot type cavity regardless of the used materials.

• The Journal of the Korean dental association
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• v.13 no.5
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• pp.415-416
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• 1975

1. The author have had a case of class V and class Ⅲ combined carious lesion extended on to root surface of upper right lateral incisor. 2. The patient was 40 years old female. 3. After routine root canal treatment of the tooth, the gingival flap was made by vertical incision on gingival tissue between distal surface of upper right lateral incisor and mesial surface of upper right canine. 4. Cavity preparation and amalgam filling on the carious lesion were performed and the flap was sutured.

• 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.24 no.1
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• pp.67-75
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• 1999

The use of composite restorative materials is established due to continuing improvements in the materials and restorative techniques. Composite resins are widely used for the restoration of cervical lesions because of esthetics, good physical properties and working time. There are several types of cavity design for class V composite resin filling, but inappropriate cavity form may affect bonding failure, microleakage and fracture during mastication. Cavity preparations for composite materials should be as conservative as possible. The extent of the preparation is usually determined by the size, shape, and location of the defect. The design of the cavity preparation to receive a composite restoration may vary depending on several factors. In this study, 5 types of class V cavity were prepared on each maxillary central incisor. The types are; 1) V-shape, 2) round(U) shape, 3) box form, 4) box form with incisal bevel and 5) box form with incisal bevel and grooves for axial line angles. After restoration, in order to observe the concentration of stress at bonding surfaces of teeth and restorations, developing a 2-dimensional finite element model of labiopalatal section in tooth, surrounding bone, periodontal ligament and gingiva, based on the measurements by Wheeler, loading force from direction of 45 degrees from lingual side near the incisal edge was applied. This study analysed Von Mises stress with SuperSap finite element analysis program(Algor Interactive System, Inc.). The results were as follows : 1. Stress concentration was prevalent at tooth-resin bonding surface of cervical side on each model. 2. In model 2 without line angle, stress was distributed evenly. 3. Preparing bevel eliminated stress concentration much or less at line angle. 4. Model with round-shape distributed stress concentration more evenly than box-type model with sharp line angle, therefore decreased possibility of fracture. 5. Adding grooves to line angles had no effect of decreasing stress concentration to the area.

• Restorative Dentistry and Endodontics
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• v.12 no.1
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• pp.107-116
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• 1986

The primary aim of this study was to assess the effects of the margin designs and composite resins on the marginal leakage of Class V resin restorations. 60 Class V cavities with $90^{\circ}$ butt joint, 60 with $45^{\circ}$ bevel joint, and 60 with concave joint were prepared on the labial surfaces of 38 extracted anterior teeth and the buccal and lingual surfaces of 71 premolars, and classified as the butt group, bevel group and concave group, respectively. After completion of the cavity preparation, Heliosit${(R)}$ was filled in 20 butt joint cavities, 20 bevel joint cavities, and 20 concave cavities. And Hi-Pol$^{(R)}$ and Palfique$^{(R)}$ were filled in the same manner, respectively. After finishing, all specimens were subjected manually to 50 thermal cycles at $4^{\circ}C$, $37^{\circ}C$, and $60^{\circ}C$. They were immersed in 0.5% methylene blue solution for 24 hours, and buccolingually sectioned with sectioning machine. The sectioned specimens were examined under the light microscope. The results indicated the following: 1. The bevel group showed the least amount of marginal leakage compared with the other two design groups, but the statistical analysis showed no significant difference at the 95% confidence level. 2. Hi-Pol$^{(R)}$ group showed the most severe marginal leakage compared with the other composite resin materials, but there was no significant difference in the groups. 3. The bevel-Heliosit$^{(R)}$ subgroup, which was filled with Heliosit$^{(R)}$ in the beveled cavities, showed the least amount of marginal leakage, but there was no significance in all the subgroups.

• Restorative Dentistry and Endodontics
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• v.13 no.2
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• pp.337-348
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• 1988

The purpose of this study was to examine the fracture strength and characteristics of teeth with MOD cavity preparation. Freshly extracted sound maxillary premolars were cleaned and stored in normal saline solution $37^{\circ}C$ for 72 hours before experiments. The roots of teeth were embedded in a self-curing resin, and the exposed crown were maintained in a vertical position by a modelling wax in a brass ring. The MOD cavities were prepared with No. 57 carbide bur under high speed to a depth of 2.0mm and a width of 2.0mm(Fig.1). All the prepared teeth specimens were divided into 7 groups according to the mode of cavity form and restorative materials (Table 1, 2): Group I, unpreapred, intact teeth as control Group II, prepared cavity without restoration Group III, prepared teeth restored with amalgam Group IV, prepared teeth restored with composite resin (P-10) Group V, prepared teeth with beveled enamel margins restored with composite resin (P-10) Group VI, prepared teeth restored with light-cured composite resin (P-30) Group VII, prepard teeth with beveled enamel margins restored with light-cured composite resin (P-30) After placement of restorations, all of the specimens were stored in water at $37^{\circ}C$ for 72 hours before testing. All of the specimens were tested on the Instron Universal Testing machine (No. 6025) in order to evaluate the strength of fracture. One metal ball 5.0mm in diameter contacting the specimens parallel to the occlusal surface was used to in this study (Fig. 1). The fracture characteristics of the specimens were examined with naked eye and in the scanning electron microscope (JSM-20). The results obtained from this study were as follows: 1. The mean fracture strength was the highest in group VI and that in group II was the lowest. 2. The progress of crack of teeth propagated into the pulp cavity. 3. In case of the group of the restored teeth, the crack occurred to be accompanied with cuspal fracture. 4. The crack of restored teeth was initiated along the pulpo-axial line angle of the cavity.

• Restorative Dentistry and Endodontics
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• v.28 no.2
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• pp.127-133
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• 2003

The object of this study was to compare the microleakage between various composite resin systems of multistep, one-bottle, and self-etching systems using electrical conductivity. After making class V cavities ($4{\times}3{\times}1.5{\;}mm$ around CEJ), they were bulk filled with three kinds of resins of A3. Teeth were storaged in a saline solution for one day, after then, they were finished and polished using Sof-Lex system. Another stress of thermocycling was made for 500 times from $5^{\circ}{\;}to{\;}55^{\circ}C$ with each dwelling time of 10 seconds. Electrical conductivity (microamphere, $\mu\textrm{A}$) was checked four times: before and after cavity preparation, after filing, after thermocycling. One-way ANOVA and 95% Scheffe Post Hoc test was used for checking any statistical difference among groups. Another 95% Paired Samples T-test was also used for estimating any significant difference within group after cavity filling or thermocycling. The results were as follows: 1 Every specimen showed various range of microleakage after filing. There was, however, no difference between composite resin systems. 2. All composite resin systems showed marked increase in microleakage with a thermocycling (p<0.05), there was, however, no difference between composite resin systems. 3. Although there was no significant difference between groups (p=0.078), one-bottle and self-etching systems seemed to be unstable than multistep system. Within the limits of this study, it was concluded that much more consideration should be needed when using thermally unstable one-bottle and self-etching systems that have multi-advantages from simplified step. More studies will be needed to solve these kinds of problems.

• Restorative Dentistry and Endodontics
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• v.29 no.2
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• pp.162-169
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• 2004

This study evaluated the marginal microleakage of five single step adhesives. Class V cavity preparations with occlusal margins in enamel and gingival margins in dentin were prepared on both buccal and lingual surfaces of extracted human molar teeth. Prepared teeth were randomly divided into five groups and restored using one of the single step adhesives and composite resins：Prompt L-Pop/Filtek Z-250 (Group 1), AQ Bond/Metafil CX (Group 2), One-Up Bond F/Palfique Toughwell (Group 3). Futurabond/Admira (Group 4), Xeno III/Spectrum TPH (Group 5). The restored teeth were thermocycled. Microleakage was assessed by dye penetration using 2% methylene blue dye solution. The teeth were bisected buccolingually and evaluated for microleakage under steromicroscope. The data were statistically analysed by Kruskal-Wallis test and Mann-Whitney tests. The results of this study were as follows：1. Microleakage of enamel margins in group 3 was statistically higher than that in groups 1, 2, 4, 5 (p < 0.05). 2. Microleakage of dentin margins in group 1 was statistically higher than that in groups 2, 5, and that in group 3 was statistically higher than that in groups 2, 4, 5 (p < 0.05). 3. Dentin marginal microleakage was higher than enamel marginal microleakage in all experimental groups. In conclusion, Prompt L-Pop showed the least leakage at enamel margin, and AQ Bond showed at dentin margin in this study. Marginal miroleakage in dentin was higher than that in enamel.

• Restorative Dentistry and Endodontics
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• v.12 no.1
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• pp.119-129
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• 1986

The purpose of this study was to evaluate the marginal leakage of glass ionomer cement with different cavosurface margins. 192 class V cavities were prepared on freshly extracted non-carious teeth and glass ionomer cement were inserted according to the manufacturer's instructions. Cavity preparations for this investigation were performed in four groups. The experimental specimens were made by packing the glass ionomer cement (Fuji Ionomer Type II G-C Co. Japan) into the prepared 192 cavities of four groups with different modes: Group I. - The 48 cavities with $90^{\circ}$ butt-joint cavosurface preparation and restored with glass ionomer cement. Group II. - The 48 cavities with butt-joint preparation modified by $135^{\circ}$ beveling the cavosurface in the dentin and restored with glass ionomer cement. Group III. - The 48 cavities with butt-joint preparation modified by cutting a chamfer in the dentin and restored with glass ionomer cement. Group IV. - The same 48 cavities as group I, and overfilled with glass ionomer cement beyond the cavosurface angle. And four groups above described divided into three subgroups by means of conditioning the cavity walls: Control group. - Glass ionomer cement filled in the prepared 64 cavities after being cleaned with a stream of tap water. Phosphoric acid treatment group. - Glass ionomer cement filled in the prepared 64 cavities after being conditioned with a 50% phosphoric acid. Citric acid treatment group. - Glass ionomer cement filled in the prepared 64 cavities after being conditioned with a 50% citric acid. All 192 specimens were immersed in the 2.0% basic fuchsin solution and subjected to thermal stress at one-minute intervals ($4{\pm}2^{\circ}C$ to $60{\pm}2^{\circ}C$) for 70 minutes before exposure to the dye. The specimens were sectioned ecclesiologically through the center of the restorations for different periods of immersion time, 24 hours, 7 days, 14 days 30 days. The sections were examined under a stereoscopic microscope. The results were as follows: 1. The degree of marginal leakage in group II and III was greater than that in group I and IV. 2. The degree of marginal leakage in phosphoric acid treatment group was similar with that in control group. 3. The degree of marginal leakage in citric acid treatment group was less than that in control group. 4. In all groups, the degree of marginal leakage in phosphoric acid treatment group was greater than that in citric acid treatment group. 5. There is no statistical difference of the degree of marginal leakage according to the immersion time in the dye solution.

• Journal of the korean academy of Pediatric Dentistry
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• v.27 no.1
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• pp.54-61
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• 2000

Amalgam, though a widely used dental material, does not bond to the tooth substrate Therefore, retentive preparation of the cavity is necessary. Such amalgam restorations, until corrosion products form and plug the margin, will show significant marginal leakage. Unless this is prevented early on, saliva and bacteria may enter the cavity causing postoperative hypersensitivity, dissolution and collapse of the restoration, discoloration of the margin and secondary caries, leading to shortened life-span of the restoration and pulpal pathosis. Recently, a method of restoration has been introduced whereby tooth material can be preserved, cavity margin can be sealed and preventive treatment of pit and fissure can be administered while retaining all the advantages of conventional amalgam restorations. Such sealed amalgams involve removing the carious lesion without extending the cavity for prevention and using pit and fissure sealants to seal cavity margins and pit and fissures to reduce microleakage. In this study, finishing of the amalgam and sealant application were performed after different intervals following of amalgam restoration to compare the microleakage of sealed and conventional amalgam restorations. Thirty bicuspids were prepared with Class V cavity preparations on the buccal and lingual surfaces. After amalgam placement, they were divided into the following groups and treated accordingly. Group 1 : Polishing after 24 hours Group 2 : Immediate sealant application without polishing Group 3 : No polishing, but sealant applied after thermocycling 500 times After treatment, the samples were thermocycled 500 times between $5^{\circ}C$ and $55^{\circ}C$ with a dwell time of 30 seconds. After thermocycling, the samples were dipped into 1% methylene blue kept in a $37^{\circ}C$ incubator at 100% humidity for 24 hours. The teeth were then embedded in resin and cut bucco-lingually along the tooth axis and observed with a stereomicroscope to determine the degree of microleakage, The following results were obtained : 1. Group 2 showed the least microleakeage, while group 1 showed the greatest. 2. Group 1 showed significantly greater microleakage compared to group 2 (p<0.05). However, no significant differences were found between group 1 and 3(p>0.05). No significant differences in microleakage were also found between cup 2 and 3(p<0.05).