• Journal of the korean academy of Pediatric Dentistry
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• v.37 no.4
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• pp.422-428
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• 2010

Giomer is fluoride-releasing, resin-based dental materials that comprise PRG(pre-reacted glass ionomer) filler. The purpose of this study was to evaluate the shear bond strength of Giomer using self-etching primer systems to bovine dentin. Bovine incisors were mounted in self-curing orthodontic resin and the facial surfaces were wet ground on SIC paper to expose the dentin. Total 100 samples were made and divided randomly into 4 groups, Giomer group(I), Composite resin group(II) and Compomer group(III), Giomer and single bottle adhesive group(IV). The shear bond strengths of 25 samples per each group were measured using universal testing machine. And data were analyzed statistically with One-way ANOVA and Scheffe test. Giomer group(I) showed the significantly higher bond strength than Compomer group(III)(p<0.05). There was no significant difference between Giomer group(I) and Composite resin group(II)(p>0.05). And there is no significant difference between gourp(I) and group(IV). Based on the results of present study, the use of Giomer as an esthetic restorative material for primary teeth might be justified. It is considered that more study about the fluoride releasing ability is needed to evaluate the anticariogenic effect of giomer.

• Journal of Dental Rehabilitation and Applied Science
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• v.30 no.2
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• pp.145-151
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• 2014

Purpose: The purpose of this study was to investigate the microleakage in class II cavity resin restorations used with resin-modified glass ionomer (RMGI) lining material depending on two different applying methods; classical delivery method using a dental explorer and a specially designed rotating bur. Materials and Methods: A total thirty-six extracted teeth were prepared with a class II proximal box, and randomly divided into three groups: 1) control group with no lining added and the proximal box restored (Group I), 2) the second group used RMGI as a lining material which was spread with an explorer (Group II), 3) the third group used a specially designed rotating bur to thin out RMGI (Group III). All teeth were restored with the same manner using incrementally placed resin composite. All 36 teeth were prepared and sectioned for the dye penetration test, and observed with a stereomicroscope for scoring the dye penetration. Results: When RMGI liners were used, both groups using an explorer and the special bur with the liner had significantly less microleakage than the control group with no liner (P < 0.05). The 50% of the group with RMGI liner using the bur showed no microleakage under a dye penetration test whereas all the teeth in control group showed microleakage of different degrees. However, there was no statistically significant difference between Group II and Group III. Conclusion: RMGI is an effective lining material to decrease microleakage in class II composite resin restorations regardless of applying methods.

• The Journal of Korean Academy of Prosthodontics
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• v.46 no.2
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• pp.201-208
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• 2008

Statement of problem: A new implant impression technique which use abutments as impression coping, and use resin cement as a splinting material was described. Accuracy of this technique was compared with conventional closed tray and resin splinted open tray technique for a $15^{\circ}$ angled 3-implant model Material and methods: A dental stone master model with 3 linearly positioned implant analogue and a reference framework which was passively fitted to it were fabricated. The center analogue was perpendicular to the plane of model and the outer analogues had a $15^{\circ}$angulation forward or backward. 10 closed tray impressions, 10 resin splinted open tray impressions, 10 abutment-resin framework cementation impressions and 10 abutment-metal framework cementation impressions were made with additional silicone material and poured with dental stone. A light microscope with image processing was used to record the vertical gap dimension between reference framework and analogue of duplicated cast made with each 4 impression techniques. Statistical analysis used one-way ANOVA with post-hoc tests Tukey test of .05 level of significance Results: Significant difference in the vertical gap dimension was found between closed tray technique; 74.3 (${\pm}33.4$)${\mu}m$ and resin splinted open tray technique, and two other new technique. (P<.05) Abutment-metal framework cementation technique;42.5 (${\pm}11.9$)${\mu}m$ was significantly different from resin splinted open tray technique. (P<.05) Abutmentresin framework cementation technique;51.0 (${\pm}14.1$)${\mu}m$ did not differ significantly from resin splinted open tray technique;50.3 (${\pm}16.9$)${\mu}m$. (P>.05) Conclusion: Within limitations of this study, the accuracy of implant level impressions of resin splinted open tray technique was superior to that of closed tray technique. A new technique using abutment and metal framework cementation was more accurate than resin splinted open tray technique.

• Restorative Dentistry and Endodontics
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• v.21 no.1
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• pp.202-217
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• 1996

The purpose of this study was to compare the degree of microleakage of Glass-Ionomer root canal sealer possessed several enviable properties with that of the other sealers and to evaluate clinical performance. One hundred twenty single-rooted teeth were used in this experiment. The teeth were cleaned mechanically and immersed for 24 hours in 5.25% sodium hypochlorite and clinical crowns then were removed. After the root canals were instrumented using a step-back technique. one hundred twenty single-rooted teeth were divided into five groups of 24 in each. Group 1 : Tubli-Seal(Kerr Co., MI, U.S.A/ZOE-based), lateral condensation Group 2 : Sealapex(Kerr/Sybron, Romulus, MI/ $Ca(OH)_2$-based), lateral condensation Group 3 : AH 26(De Trey Co., Zurich Switzerland/Resin-based), lateral condensation Group 4 : Ketac-Endo(ESPE GMBH & CO. KG Seefeld:oberbay. Germany/ Glass Ionomer Cement-based), lateral condensation Control group : no sealer. lateral condensation And then. the root canals were obturated by lateral condensation technique with gutta-percha and experimental sealers. The control group were obturated without sealer. The teeth were placed in a vacuum chamber for 15 minutes and immersed 2% methylene blue under vacuum for 15 minutes. The teeth were passively stained for 1 week and 2 weeks and were cleared and evaluated for linear dye leakage using Tool maker's microscope(${\times}200$). The results were as follows: 1. There were statistically significant differences in the degree of dye penetration between the control group and experimental groups(p<0.05). 2. In the experimental groups, Sealapex($1.2871{\pm}0.9180mm$) exhibited the lowest mean value of dye penetration, followed by Ketac-Endo($1.4432{\pm}0.8082mm$), AH 26($1.5030{\pm}0.7752mm$) and Tubli-Seal($1.6458{\pm}1.0292mm$)(p>0.05). 3. There were statistically significant differences in the variation of microleakage between 1 week and 2weeks in Tubli-Seal and Seal apex groups (p<0.05). 4. The degree of dye penetration of all groups were increased as the time elapsed and AH 26 showed the lowest variation(+0.11) and Tubli-Seal(+ 1.03) showed the highest variation (p<0.001).

• Journal of dental hygiene science
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• v.8 no.4
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• pp.353-359
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• 2008

To find out the relationship between the experience of clinical practice and the performance confidence, some 2nd and 3rd grade students in D health college who completed clinical practice in 2008. Sept. were surveyed. The results are as follows. 1. During the clinical practice of the dental hygiene students, the performance experience was highest in the basic prep. part among every part. As for the dental hygiene part, the students showed more than 70%, rather higher performance experience in the following parts: arrangement before and after treatment, suction, basic instruments setup, local anesthesia setup, extraction setup, resin filling setup, temporary filling setup, cements mixing, and ligation and removal setup. 2. As for performance confidence, those with performance experience showed higher performance confidence than those with only observation experience or with no experience in every treatment field except basic prep. (p < 0.001). 3. It was proven that the hygiene students have seldom had performance experience in other treatment parts except in assisting treatment part in clinical practice. In order to improve future performance experience on dental hygiene activities, subsequent research is needed to set more specific and objective criterion about the dental hygiene students' clinical practice.

• Restorative Dentistry and Endodontics
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• v.25 no.3
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• pp.399-406
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• 2000

The effect of inlay surface treatment on bonding was investigated when resin inlay was bonded to resin-modified glass-ionomer base with resin cement. For the preparation of glass-ionomer base, resin-modified glass-ionomer cement (Fuji II LC, GC Co., Japan) was filled in class I cavities of 7mm in diameter and 2mm in depth made in plastic molds. Eighty eight resin inlay specimens were made with Charisma$^{(R)}$ (Kulzer, Germany) and then randomly assigned to the four different surface treatment conditions: Group I, $50{\mu}m$ aluminium oxide sandblasting and silane treatment ; Group II, silane treatment alone ; Group III, sandblasting alone, and Group IV (control), no surface treatment. After a dentin bonding agent with primer (One-Step$^{TM}$, Bisco Inc., IL., U.S.A.) was applied to bonding surface of resin inlay and base, resin inlay were cemented to glass-ionomer base with a resin cement (Choice$^{TM}$, Bisco Inc., IL., U.S.A.). Shear bond strengths of each specimens were measured using Instron universal testing machine (4202 Instron, lnstron Co., U.S.A.) and fractured surfaces were examined under the stereoscope. Statistical analysis was done with one-way ANOVA and Dunkan's multiple range test. The results were as follows: 1. Sandblasting and silane treatment provided the greatest bond strength(10.56${\pm}$1.95 MPa), and showed a significantly greater bond strength than sandblasting alone or no treatment (p<0.05). 2. Silane treatment provided a significantly greater bond strength(9.77${\pm}$2.04 MPa) than sandblasting alone or no treatment (p<0.05). However, there was no significant difference in bond strength between sandblasting treatment and silane one (p>0.05). 3. Sandblasting alone provided no significant difference in bond strength from no treatment (p>0.05). 4. Stereoscopic examination of fractured surface showed that sandblasting and silane treatment or silane treatment alone had more cohesive failure mode than adhesive failure mode. 5. In relationship between shear bond strength and failure mode, cohesive failure occurred more frequently as bond strength increased.

• Journal of the korean academy of Pediatric Dentistry
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• v.26 no.3
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• pp.520-527
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• 1999

For the purpose of providing some suggestions in selection of filling materials used in 'sandwich technique', the bond strengths between glass ionomer cement bases and composite resins were investigated and compared. For lining materials, 'Vitrebond' and 'Ketac-fil' were used. Using these two as bases, 10 of each following resins were built up on the top ; Z-100 (light curing resin) Clear-fil (chemical curing resin), Bis-core (dual cure resin), Dyract (compomer), therfore 10 specimens of each group and total of 80 specimens were made. After storing specimens in $37^{\circ}C$ deionized water for 24 hours, the shear bond strengths were measured under universal testing machine with 50 kg of full load scale and 1mm/min of cross-head speed and obtained the results as follows : 1. Over Vitrebond base, Z-100 showed the lowest bond strength but the other three did not show any difference in bond strength. 2. Over Ketac-fil base, Clear-fil showed the highest bond strength followed by Dyract, Bis-core, and Z-100 showed the lowest bond strengths. 3. Whereas Clear-fil showed the similar bond strengths on the Vitrebond base as other resins, it showed the highest bond strength on Ketac-fil base, which showed some difference in bond strength by differing GIC bases. 4. The bond strengths between base materials and composite resin showed a stronger resin-dependence tendency in cases with Ketac-fil bases rather than with Vitrebond bases.

• Journal of the korean academy of Pediatric Dentistry
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• v.31 no.3
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• pp.474-480
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• 2004

The purpose of this in vitro study was to compare the remineralizing effects of three glass ionomer cements (high filled glass ionomer cement, compomer, resin modified glass ionomer cement) with resin composite (control group) on incipient interproximal caries, and to assess long-term change of remineralization effect, in each material, evaluated by microtomography. Proximal restoration was simulated with tooth specimen and Glass Ionomer Cements. And each of these groups was placed into a closed container with artificial saliva at $37^{\circ}C$ and pH 7.0 for a time period of thirty days with constant circulation. At the end of thirty and sixty days, tomographic images were taken from these specimens with micro CT scanner. Materials used in this study were as follows. Group 1: Fuji IX GP (GC Corp., Tokyo, Japan) Group 2: Vitremer (3M ESPE, St. Paul, Minn., USA) Group 3: F2000 (3M ESPE, St. Paul, Minn., USA) Group 4: Z250 (3M ESPE, St. Paul, Minn., USA) Using density-measuring program, the micro-density of carious lesions on the specimens were measured. The mean density changes of each group were compared to the other groups to evaluate the effect of remineralization. The results were as follows: 1. The lesion density of all groups increased. 2. The mean density increase of Group 1, 2, 3 were higher than that of Group 4 every month(p<0.05). 3. There were significant differences of density increase among glass ionomer group(Group 1, 2, 3).

• Journal of the korean academy of Pediatric Dentistry
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• v.35 no.1
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• pp.175-180
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• 2008

Traumatic injuries to the primary dentition are commonly encountered problems in dental practice. It is found that 30% of the children had injuries to the primary dentition and 22% to the permanent dentition. The greatest incidence of trauma to the primary dentition occurs at the ages of 2 and 3 as children start to learn motor coordination. Because teeth and alveolar bone are traumatized simultaneously, alveolar bone fractures are likely to occur when multiple teeth are involved in injuries. Dental splints are indicated for the management of maxillofacial fractures. They enable anatomic reduction of fractured segments and help immobilization and maintenance of the fragments after reduction. They also act as a stabilizer during rehabilitation. Various types of dental splints are available. In this case, routine resin-wire splint technique could not be applied because of the child's uncooperative behavior. Oral sedation was not indicated because N.P.O. had not been preceded. Therefore, we decided to use open-cap acrylic splint instead. Stabilization using open cap acrylic splint requires minimum chair time with reduced discomfort to both patient and dentist. It is an effective means of splint for uncooperative children and especially useful when other means of fixation have been failed. Because trauma on the primary dentition can affect the underlying permanent tooth germ, it is important to monitor eruption process of the permanent dentition.

• The Journal of Korean Academy of Prosthodontics
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• v.47 no.2
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• pp.148-155
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• 2009

Statement of problem: The interest in all-ceramic restorations has increased as more techniques have become available. With the introduction of machinable dental ceramics and CAD/CAM systems there is a need to evaluate the quality levels of these new fabrication techniques. Purpose: This study is to evaluate the crown fidelity(absolute marginal discrepancy and internal gap) of various zirconia-based all-ceramic crowns fabricated with different CAD/CAM(computer-assisted design/computer-assisted manufacturing) systems and conventional cast metal-ceramic crowns. Material and methods: A resin tooth of lower right second premolar was prepared. After an impression was taken, one metal master die was made. Then 40 impressions of metal master dies were taken for working dies. 10 crowns per each system were fabricated using 40 working dies. Metal-ceramic crowns were cast by using the conventional method, and Procera, Lava, and Cerec inLab crowns were fabricated with their own CAD/CAM manufactruing procedures. The vertical marginal discrepancies and internal gaps of each crown groups were measured on a metal master die without a luting agent. The results were statistically analyzed using the one-way ANOVA and Tukey's HSD test. Results: 1. Vertical marginal discrepancies were $50.6{\pm}13.9{\mu}m$ for metal-ceramic crowns, $62.3{\pm}15.7{\mu}m$ for Procera crowns, $45.3{\pm}7.9{\mu}m$ for Lava crowns, and $71.2{\pm}2.0{\mu}m$ for Cerec inLab crowns. 2. The Internal gaps were $52.6{\pm}10.1{\mu}m$ for metal-ceramic crowns, $161.7{\pm}18.5{\mu}m$ for Procera crowns, $63.0{\pm}10.2{\mu}m$ for Lava crowns, and $73.7{\pm}10.7{\mu}m$ for Cerec inLab crowns. Conclusion: 1. The vertical marginal discrepancies of, 4 crown groups were all within the clinically acceptable range($120{\mu}m$). 2. The internal gaps of LAVA, Cerec inlab, and metal-ceramic crowns were within clinically acceptable range except Procera crown($140{\mu}m$).