• Journal of the korean academy of Pediatric Dentistry
• /
• v.24 no.2
• /
• pp.436-448
• /
• 1997

Topical fluoride application for children is a widely performed procedure in the field of Pediatric Dentistry for its dental caries prevention effects. However, it is recently recognized as having some unwanted effects on several esthetic restorative materials as it roughens the surfaces of the restorative materials. In order to evaluate the surface changes in esthetic restorative materials, the author immersed composite resin, glass ionomer cement, and resin-modified glass ionomer cement specimens in various topical fluoride agents and measured the weight loss and also, examined the specimens under the scanning electron microscope. The followings are the results : 1. All the specimens immersed in APF gel for 4 minutes showed statistically significant weight loss. (paired t-test, P<0.05). 2. There was no statistically significant weight loss for the resin-modified glass ionomer cement and composite resin groups immersed in sodium fluoride solution (paired t-test, P>0.05). 3. When the glass ionomer cement group was immersed in APF gel for 1 and 4 minutes, there was a statistically significant weight loss compare to other esthetic restorative materials (ANOVA, P<0.05). 4. In the resin-modified glass ionomer cement group and the composite resin group, weight loss in the APF gel 4 minutes immersion group was greater than the 1 minute immersion group, and it was statistically significant (ANOVA, P<0.05). 5. When the specimens were examined under scanning electron microscope, the surface changes were greatest in the order of glass ionomer cement, resin-modified glass ionomer cement, composite resin and also in the order of APF gel 4 minute immersion group, 1 minute immersion group, sodium fluoride immersion group, and control group.

• Restorative Dentistry and Endodontics
• /
• v.22 no.2
• /
• pp.792-800
• /
• 1997

The purpose of this study was to evaluate the adaptation of self-cured glass ionomer cement and resin-modified glass ionomer cement and polyacid-modified resin composite, which are light-cured giass ionomer cements, to dentin surface. Twelve extracted human maxillary and mandibular molar teeth were used in this study. The entire occlusal dentin surfaces of teeth were exposed with Diamond Wheel Saw and smoothed with sand papers (300, 600, 1200grits). They were randomly assigned into 3 groups according to glass ionomer cements used; Control group- Fuji II, Expeimental group 1 - Fuji II LC, Expeimental group 2 - Dyract. According to the manufacturer's directions, three glass ionomer cements were bonded to exposed dentin surfaces of the tooth crown and cured. Crowns and glass ionomers were trimmed after 24hrs and sectioned horizontally and vertically with diamond saw. The interface of glass ionomer cements and dentin was examined under SEM. The results were as follows : 1. Good adatation between glass ionomer cement and dentin on the horizontal section was showed in control and experimental group 1, but the gap of $20{\mu}m$, which was observed distinct separation between glass ionomer cement and dentin, was showed in experimental group 2. 2. Good adatation between glass ionomer cements and dentin on the vertical section was showed in control and experimental group 1, but the gap of 80-$100{\mu}m$ was showed in experimental group 2. 3. Cohesive fracture within glass ionomer cements in control and experimental group 1 was showed, but no cohesive fracture was showed in experimental group 2.

• Restorative Dentistry and Endodontics
• /
• v.25 no.3
• /
• pp.313-320
• /
• 2000

The purpose of this study was to evaluate on the interfacial morphology between dentin and restorative materials. In this in vitro study, the cavity wall restorated with 3 different kinds of tooth colored restorative materials [resin-modified Glass Ionomer cement (Fuji II LC), composite resin (Z-100), compomer (Dyract)]. The thirty extracted human molar teeth without caries and/or restorations are used. The experimental teeth were randomly divided into three groups of ten teeth each. In each group, Wedge shaped cavities (width: 3mm, length: 2mm, depth: 1.5mm) were prepared at the cementoenamel junction on buccal and lingual surfaces. The adhesive of composite resin were mixed with rhodamine B. Primer of composite resin, Prime & Bond 2.1 of Dyract and liquid of Fuji II LC were mixed with fluorescein. In group 1, the cavity wall was treatment with dentin conditioner, and then restorated with Fuji II LC. In group 2, the cavity wall was treatment with Prime & Bond 2.1 and then restorated with Dyract. In group 3, the cavity wall was etching with 10% maleic acid, applied with primer and bonding agent and then restorated with Z-100. The interface between dentin and restorative materials was observed by fluoresence imaging with a confocal laser scanning microscope. The results were as follows : 1. In Glass ionomer group, adaptation of resin modified Glass-ionomer restoration against cavity wall is tight, but the crack formed inside of restoration were observed. 2. In Dyract group, the penetration of resin tag is shorter and the width of hybrid layer is narrower than composite resin group. 3. In Z-100 group, primer penetrated deeply through dentinal tubule. Also bonding agent was penetrated along the primer, but the penetration length is shorter than primer part, and in 3-D image, the resin tag is conical shape and lateral branch is observed.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.27 no.3
• /
• pp.410-418
• /
• 2000

An in vitro study was performed to evaluate the effect of four variables on the temperature rise produced by polishing of restorations. The four variables were : restorative material, base, thickness of remaining dentin, continuous polishing or intermittent polishing. Class V cavities were cut on extracted molar and restored with composite resin, resin-modified glass ionomer cement, compomer, amalgam on the various bases (glass ionomer cement, zinc oxide eugenol cement, zinc phosphate cement) Dentin thickness under the restoration was 0.5mm, 1.5mm. Polishing was done with an aluminum oxide-coated disc. Polishing time was continuous or intermittent for up to 1 minute. Intra-pulpal temperature increased almost linearly in all cases. Amalgam produced highest temperature rises at the pulp, while the composite resin, resin-modified glass ionomer cement and compomer were not different for each other. The rate and extent of temperature rising of amalgam restoration was reduced by presence of a cement base. Zinc oxide eugenol cement bases showed the highest temperature rise, while glass ionomer cement, zinc phosphate cement were not different to the untreated tooth Thickness of remaining dentin was only significant for the amalgam restoration. Continuous polishing produced higher temperature rise than intermittent polishing.

• Journal of Periodontal and Implant Science
• /
• v.29 no.3
• /
• pp.621-636
• /
• 1999

When mucoperiosteal flaps are positioned and sutured to desirable position, the wound contains several interface between tissues which differ fundamentally in composition & biological reaction. Thus the C-T surface of the flap will, on one hand, oppose another vascularized surface, and on the other, the avascular dental material for example, when root resoptions, fractured root, endodontic perforation, deep root carious lesions were filled with amalgam, glass ionomer, resin etc. Recently, a number of case report described the successful treatment of a subgingival root lesion with restorative material & free gingival graft, open flap surgery, but more objective research was needed . Most of study on restorative materials were concerned for cytotoxicity not for actual healing event on that materials and its influencing factors such as biocompatibility, surface wettability, surface topography . The aim of this in vitro study was to evaluate the effect of amalgam, resin modified glass ionomer, composite resin per se, and their surface roughness on the growth of human gingival fibroblast. The cells were obtained and placed on culture flask and incubated for 3 days with the prepared test materials. Then count the attached cell number with hemocytometer,(n=12) and 2 samples were examined with SEM about attachment cell morphology . Another 4 samples were evaluated on their surface roughness with Talysurf and average surface roughness value(Ra) were obtained. Statistical difference in attached cell number, roughness value were analyzed using ANOVA. The number of attached cell was as follows, for root dentin specimen 16.7${\pm}$4.41, resin modified glass ionomer 14.0${\pm}$4.15, resin 8.13${\pm}$3.63, amalgam 0.72${\pm}$3.33(${\times}10^3$). Between root dentin and resin-modified glass ionomer, no significant difference was observed, but resin, amalgam showed a significant less cell numbers than for root dentin, resin modified glass ionomer cement. SEM examination expressed many cell surface attachment apparatus in root dentin and resin modified glass ionomer specimens. For resin specimen, cell attachment was observed but exposed less appratus. The average surface roughness value are following results. Dentin specimen 0.6972${\pm}$ 0.104, resin modified glass ionomer 0.0822${\pm}$0.009, resin 0.0875${\pm}$0.005, amalgam 4.2145${\pm}$0.985(${\mu}m$). Between root dentin, resin-modified glass ionomer, and resin, no significant difference was observed, but amalgam showed a significant more rough surface than other groups. When evlauated the interrelationship between cell attachment and surface roughness, therefore, there was weak reverse correlation.(pearson correlation : - 0.593) These results suggest that resin modified glass ionomer have the favorable healing potential when used for subgingival restoration. And for relationship between cell attachment and surface characteristics, further investigations were needed.

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

• The Journal of Advanced Prosthodontics
• /
• v.8 no.2
• /
• pp.144-149
• /
• 2016

PURPOSE. The use of temporary or permanent cements in fixed implant-supported prostheses is under discussion. The objective was to compare the retentiveness of one temporary and two permanent cements after cyclic compressive loading. MATERIALS AND METHODS. The working model was five solid abutments screwed to five implant analogs. Thirty Cr-Ni alloy copings were randomized and cemented to the abutments with one temporary (resin urethane-based) or two permanent (resin-modified glass ionomer, resin-composite) cements. The retention strength was measured twice: once after the copings were cemented and again after a compressive cyclic loading of 100 N at 0.72 Hz (100,000 cycles). RESULTS. Before loading, the retention strength of resin composite was 75% higher than the resin-modified glass ionomer and 2.5 times higher than resin urethane-based cement. After loading, the retentiveness of the three cements decreased in a non-uniform manner. The greatest percentage of retention loss was shown by the temporary cement and the lowest by the permanent resin composite. However, the two permanent cements consistently show high retention values. CONCLUSION. The higher the initial retention of each cement, the lower the percentage of retention loss after compressive cyclic loading. After loading, the resin urethane-based cement was the most favourable cement for retrieving the crowns and resin composite was the most favourable cement to keep them in place.

• Imaging Science in Dentistry
• /
• v.30 no.4
• /
• pp.243-248
• /
• 2000

Purpose: The aim of this study was to determine the relative radiopacities of cavity lining materials (Resin-modified Glass Ionomer cement, Compomer and Plowable resin) for posterior composite resin restoration. Material & Methods: Resin-modified glass ionomer cement (Fuji II LC, Vitrebond/sup TM/), Compomers (Dyract /sup (R)/ Compoglass, F2,000, Dyract/sup (R)/ flow Compoglass Flow) and Flowable resins (Tetric/sup (R)/ flow, Aeliteflo/sup TM/ Revolution/sup TM/) were used. Five specimens of 5 mm in diameter and 2 mm thick were fabricated with each material. Human molars were horizontally sectioned 2 mm thick to include both enamel and dentin. The radiopacities of enamel, dentin, cavity lining materials, aluminum step wedge were obtainded from conventional radiograph and NIH image program. Results: All the tested lining materials showed levels of radiopacity the same as or greater than that of dentin. All compomer tested (Dyract, Compoglass, F2,000, Dyract flow, Compoglass Flow) and Vitrebond/sup TM/, Tetric/sup (R)/ flow were more radiopaque than enamel. The radiopacities of Fuji II LC and Revolution/sup TM/ were between enamel and dentin and resin-modified glass ionomer cement, Compomer and Tetric/sup (R)/ flow were greater than those of Revolution/sup TM/, Aeliteflo/sup TM/ or dentin. The level of radiopacity of the tested materials was variable; those with low radiopacity should be avoided in class II restorations, where a clear determination of recurrent caries by the examining clinician could be compromised. Conclusion: Clinician should be able to distinguish these cavity lining materials radiographically from recurrent decay, voids, gaps, or other defects that lead to clinical failure. Utilization of materials ranked more radiopaque than enamel would enable clinicians to distinguish the lining material from tooth structure.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.25 no.1
• /
• pp.234-248
• /
• 1998

The purpose of this study was to compare the fracture and shear bonding strength of resin-modified glass ionomer cements with composite resin and conventional glass ionomer cement Three kinds of restorative materials including a composite resin (Z 100), a conventional glass ionomer cement(Fuji II), and resin- modified glass ionomer cements(Fuji II LC, Vitremer, Dyract and Compoglass) were investigated in this study. For measurement of fracture and shear bonding strength, disk samples of the materials were prepared and cylindrical samples of the materials were bonded the flat enamel and dentin surfaces according to manufactuer's instructions. All specimen were determinated by using an Instron testing machine with a crosshead speed of 1 mm/min. Then, each treated enamel and dentin surface was observed by SEM. The following results were obtained. 1. The bi-axial flexural strength of Z 100 was highest, and Fuji n LC, Vitremer, Dyract and Compoglass were significantly higher than Fuji n (P<0.05). 2. The shear bonding strength of Z 100 on the enamel and dentin surface was higher than other experimental groups except Fuji II LC(P<0.05). Fuji II LC was significantly higher than Fuji II (P<0.05), but in the case of Vitremer, Dyract and Compoglass were similar to Fuji II (P>0.05). 3. The shear bonding strength of Z 100 and Fuji II LC on the enamel surface were highly increased as compared with dentin surface (P<0.05), but in the case of Fuji II, Vitremer, Dyract and Compoglass were not different between enamel and dentin(P>0.05). 4. In the Z 100 and Fuji II LC, obvious etched enamel surface and exposed dentinal tubules according to remove of smear layer and smear plug were observed.

• Journal of Korean Dental Science
• /
• v.16 no.1
• /
• pp.74-79
• /
• 2023

Purpose: Cention N (Ivoclar Vivadent) was a recently introduced alkasite-based restorative material that was expected to replace amalgam and glass ionomer cement. This material was an esthetic restoration with adequate mechanical strength and release of fluoride and calcium. The purpose of this study was to measure the water sorption and water solubility of Cention N and evaluate its long-term durability compared to other esthetic restorations (Resin-Modified Glass Ionomer cement [RMGIC], Giomer, Composite Resin). Materials and Methods: Twenty specimens each of Cention N (CN), Resin Modified-Glass Ionomer Cement (FJ), Giomer (BF), and Composite Resin (FZ) were made. After each specimen was completely dried in a desiccator for 24 hours using a vacuum pressure pump, the specimen was weighed (m1). After that, the specimen was immersed in distilled water at 37℃ for 7 days, stored in a drying oven, and weighed (m2). After drying completely for 24 hours in a desiccator, the specimen was weighed (m3) to calculate the water absorption and water solubility using Formulas 1 and 2. The measured values were statistically processed and analyzed using SPSS, and the significance level was set at 0.05. Result: When measuring water sorption, FJ (122.61 ㎍/mm³) showed significantly higher water sorption than CN (35.42 ㎍/mm³) (P<0.05). There was no significant difference between FZ (18.03 ㎍/mm³) and BF (14.76 ㎍/mm³) (P=0.930). When measuring water solubility, CN (6.65 ㎍/mm³) showed significantly higher water solubility than FJ (1.47 ㎍/mm³) (P<0.05). Conclusion: Cention N had lower water sorption than RMGIC, but higher water solubility, indicating that it is more vulnerable to moisture and has lessened long-term durability.