• Journal of Dental Rehabilitation and Applied Science
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• v.30 no.2
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• pp.102-111
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• 2014

Purpose: Surface damage and bonding strength difference after micromechanical treatment of zirconia surface are to be studied yet. The aim of this study was to evaluate the difference of fracture resistance and bonding strength between more surface-damaged group from higher air-blasting particle size and pressure, and less damaged group. Materials and Methods: Disk shape zirconia ($LAVA^{TM}$) was sintered and air-blasted with $30{\mu}m$ particle size (Cojet), under 2.8 bar for 15 seconds, $110{\mu}m$ particle size (Rocatec), under 2.8 bar for 15 seconds, and $110{\mu}m$ particle size (Rocatec), under 3.8 bar for 30 seconds respectively. Biaxial flexure test and bonding failure load test were performed serially (n = 10 per group). For bonding test, specimens were bonded on the base material having similar modulus of elasticity of dentin with $200{\mu}m$-thick resin cement for tension of surface damage. Failure load of bonding was detected with acoustic emission (AE) sensor. Results: There were no significant differences both in the biaxial flexure test and bonding failure load test between groups (P > 0.05). Sub-surface cracks were all radial cracks except for two specimens. Conclusion: Within the limitations of no aging under monotonic load test, surface damage from higher air-blasting particle size and pressure was not significant. Evaluations of failure load with bonded zirconia disks was clinically relevant modality for surface damage and bonding strength, simultaneously.

• The Journal of Korean Academy of Prosthodontics
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• v.55 no.3
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• pp.264-271
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• 2017

Purpose: The purpose of this study is to investigate the differences in bond strength of four different indirect composites to the gold alloy and Ni-Cr alloy according to type of metal surface treatment after water storage. Materials and methods: Type IV gold alloy and Ni-Cr alloy were used for casting alloy while four types of indirect composite resins (Gradia, Tescera Sinfony and in;joy) were used in this study. Metal specimens were produced by casting and total of 240 specimens (60 specimens per one indirect composite group) were prepared. After bonding indirect composite resin and undergoing 24 hours of polymerization, customized jig was attached to the metal specimen and shear bond strength were measured using universal testing machine. Also, differences in shear bond strength before and after water storage for 240 hours were also measured. Results: In the measurement of shear bond strength according to the metal surface treatments, bead group showed high strength followed by loop and flatting group (P<.05). After being stored in water bath for 240 hours, Gradia showed statistically significant high bond strength compared to other indirect composite resins in all groups (P<.05). Conclusion: Shearbond strength was found to be different according to type of metal surface treatment and type of metal used after storage in water. Further studies need to be developed for clinical practices as three are still problems of microleakage, stain or wear.

• Journal of Dental Rehabilitation and Applied Science
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• v.34 no.2
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• pp.89-96
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• 2018

Purpose: The aim of this study was to evaluate the effect of delayed time, surface treatment, and repair materials on repair of bis-acryl composite resin through comparison of shear bond strength and to evaluate the utility of bis-acryl composite resin repair using polymethyl methacrylate resin. Materials and Methods: A total of 90 bis-acryl composite resin specimens were fabricated and classified into 9 test groups, each of 10 pieces according to delayed time, surface treatment and repair material. The shear bond strength of each specimen was measured using a universal testing machine immediately after fabrication and analyzed using a statistical analysis program (IBM SPSS statistics 20). After the shear bond strength measurement, the fracture surface of the specimen was observed. Results: The highest shear bond strength ($17.54{\pm}3.14MPa$) was observed in the experimental group bonded immediately with a light-curing flowable composite resin using a bonding agent. Conclusion: When repairing bis-acryl composite resin, it is necessary to consider whether to remake according to the delayed time. For effective repair, it is desirable to consider appropriate materials and surface treatment methods according to the site or purpose of use.

• Restorative Dentistry and Endodontics
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• v.30 no.6
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• pp.493-504
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• 2005

This study was performed to investigate the compatibility between 4 dentin adhesives and 4 resin luting cements. Dentin adhesives used in this study were All-Bond 2 (Bisco Inc., Schaumbrug, IL, USA), Clearfil SE-Bond (Kuraray Medical Inc, Osaka, Japan), Prompt L-Pop (3M Dental Products, St. Paul, MN, USA), One-Up Bond F (Tokuyama corp., Tokyo, Japan) Resin luting cements used in this study were Choice (Bisco Inc., Schaumbrug, IL, USA), Panavia F (Kuraray Medical Inc, Osaka, Japan), RelyX ARC (3M Dental Products, St. Paul, MN, USA) Bistite II DC (Tokuyama corp., Tokyo, Japan). Combination of each dentin adhesive and corresponding resin cement was made to 16 experimental groups. Flat dentin surfaces was created on mid-coronal dentin of extracted mandibular third molars, then dentin surface was polished with 320-grit silicon carbide abrasive papers. Indirect resin composite block (Tescera, Bisco) was fabricated. Its surface for bonding to tooth was polished with silicon carbide abrasive papers Each dentin adhesive was treated on tooth surface and resin composite overlay were luted with each resin cement. Each bonded specimen was poured in epoxy resin and sectioned occluso-gingivally into 1.0mm thick slab, then further sectioned into $1.0{\times}1.0mm^2$ composite-dentin beams. Microtensile bond strength was tested at a crosshead speed of 1.0mm/min. The data were analysed by one-way ANOVA and Duncan's multiple comparison tests The results of this study were as follows, 2-step self-etching dentin adhesive which has additional bonding resin is more comparison than tests. self-etching dentin adhesive.

• Journal of Dental Rehabilitation and Applied Science
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• v.28 no.1
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• pp.67-78
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• 2012

The purpose of this study was to determine whether there were differences in shear bond strength to human dentin using IDS technique compared with DDS. Forty freshly extracted human molars were and devided into 4 groups. The control group specimens were, on the morrow of tooth preparation, light-cured after application of dentin bonding agent and cemented with resin cement. The IDS/SE(immediate dentin sealing, Clearfil$^{TM}$ SE Bond) and IDS/SB (immediate dentin sealing, Adapter$^{TM}$ Single Bond 2) specimens were, on the morrow of tooth preparation, light-cured after application of dentin bonding agent(Clearfil$^{TM}$ SE Bond and Adapter$^{TM}$ Sing Bond 2, respectively), whereas DDS specimens were not treated with any dentin bonding agent. IDS/SE, IDS/SB and DDS specimens were thermocycled. Following that delay, specimens were cemented with resin cement. The dentin bonding agent was left unpolymerized until the application of porcelain restoration. Shear bond strengths were measured using a universal testing machine. Specimens also were evaluated for mode of fracture using an optical microscope. The mean shear bond strengths of control group and IDS/SE groups were not statistically different from one another. The bond strength of IDS/SE group had a significantly higher mean than that of DDS group. There was no significant difference in the mean shear bond strength between IDS/SB(4.11MPa) and DDS group. The evaluation of failure modes indicates that most failures in the control group and IDS/SE groups were mixed, whereas failures in the DDS group were interfacial. When preparing teeth for indirect ceramic restoration, IDS with Clearfil$^{TM}$ SE Bond results in improved shear bond strength compared with DDS.

• The korean journal of orthodontics
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• v.25 no.2 s.49
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• pp.223-233
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• 1995

The purpose of this study was to evaluate the effects of surface conditioning with $10\%$ polyacrylic acid, etching with $38\%$ phosphoric acid, and polishing with a slurry of pumice on shear bond strengths of light-cured glass ionomer cement, chemically cured glass ionomer cement, and a composite resin to enamel, and to observe the failure patterns of bracket bondings. Shear bond strengths of glass ionomer cements were compared with that of a composite resin. Metal brackets were bonded on the extracted human bicuspids after enamel surface treatments, and samples were immersed in the $37^{\circ}C$ distilled water bath, and shear bond strengths of glass ionomer cements and a composite resin were measured on the Instron machine after 24hrs passed, and the deboned samples were measured in respect of adhesive remnant index. Scanning electron micrographs were taken of enamel surfaces after various treatments. The data were evaluated and tested by ANOVA and Duncan's multiple range test, and those results were as follows. 1. Shear bond strength of light-cured glass ionomer cement showed statistically higher than that of chemically cured glass ionomer cement. 2. Shear bond strengths of light-cured and chemically cured glass ionomer cements to enamel treated with $10\%$ polyacrylic acid and $38\%$ phosphoric acid showed statistically higher than those with a slurry of pumice. 3. According to scanning electron micrographs, enamel surface conditioned with $10\%$ polyacrylic acid is slightly etched and cleaned, that etched with $38\%$ phosphoric acid is severely etched, and that polished with a slurry of pumice is irregulary scretched and not completely cleaned. 4. After debonding, light-cured glass ionomer cement to enamel treated with $10\%$ polyacrylic acid showed less residual materials on the enamel solace than composite resin to enamel etched with $38\%$ phosphoric acid. 5. There was no significant difference in the shear bond strength of light-cured glass ionomer cement to enamel treated with $10\%$ polyacrylic acid and that of composite resin to enamel etched with $38\%$ Phosphoric acid.

• The korean journal of orthodontics
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• v.34 no.4 s.105
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• pp.333-342
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• 2004

The purpose of this study was to evaluate the clinical effectiveness of a plasma arc light and light emitting diode (LED), compared with shear bond strength and the failure pattern of brackets bonded with visible light in direct bonding. Brackets were bonded with Transbond XT to 60 human premolars embedded in the resin blocks according to different light-curing methods. Then, the shear bond strength of each group was measured using a universal testing machine (Instron) and the adhesive failure pattern after debonding was visually examined by light microscope. The results were as follows: 1. The shear bond strength showed no significant difference between the visible light and light emitting diode, but the plasma arc light exhibited a significantly lower shear bond strength compared with the visible light and light emitting diode. 2. In the visible light and light emitting diode, adhesive failure patterns were similar. Bond failure occurred more frequently at the enamel-adhesive interface. 3. The bonding failure of brackets bonded with plasma arc light occurred more frequently at the bracket-adhesive interface. The results of this study suggest that plasma arc light, light emitting diode and visible light are all clinically useful in the direct bonding of orthodontic brackets.

• The korean journal of orthodontics
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• v.26 no.3
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• pp.301-307
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• 1996

The purpose of this study was to evaluate the effect of surface treatment of porcelain on tensile bond strength. To accomplish this purpose, this study was carried out with 120 samples which were divided into 12 groups with each 10 samples, and the first group was not surface treated, groups 2 through 5 underwent single surface treatment, and groups 6 through 12 underwent compound surface treatment. The results were as follows : 1. In statistic, all the single surface-treated groups showed higher tensile bond strength than the non surface-treated group and the sandblasted group showed the highest tensile bond strength as $10.34{\pm}2.50MPa$. 2. All the compound surface-treated groups showed no noticeable difference in the tensile bond strength(9-11.5MPa). 3. In statistic, no significant difference was found between the sandblasted group and the compound surface-treated groups. 4. There was no fracture of porcelain while testing in this study. Above study demonstrated that compound surface treatment or sandblasing, if used single surface treatment, should be employed to guarantee successful clinical application.

• The Journal of Korean Academy of Prosthodontics
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• v.51 no.1
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• pp.20-26
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• 2013

Purpose: The purpose of this study was to evaluate the bond strengths between the latest CAD/CAM ceramic inlay and various resin cements which are used primarily for esthetic restoration. Materials and methods: Cylindrical ceramic blocks(Height: 5 mm, diameter: 3 mm) were fabricated by using Cerec3 and bonded on the dentin of the ninety extracted caries-free molars using three different kinds of resin cement(Unicem$^{(R)}$, Biscem$^{(R)}$, and Variolink II$^{(R)}$) according to the manufacturer's instructions. Ninety specimens were divided into 3 groups according to three different kinds of resin cement. Half of each group were conducted thermocycling under the conditions of the $5-55^{\circ}C$, 5,000 cycle but the other half of them weren't. All specimens were kept in normal saline $37^{\circ}C$, for 24 hours before measuring the bond strength. The shear bond strength was measured by Universal testing machine with a cross head speed of 0.5 mm/min. The results were analyzed statistically by t-test and one-way ANOVA. Results: Unicem$^{(R)}$ group showed the highest shear bond strength despite a slight decline by thermocycling. The shear bond strength of Unicem$^{(R)}$ group and ValiolinkII$^{(R)}$ group were significantly influenced by thermocycling, whereas Biscem$^{(R)}$ group was not influenced (P<.05). There were no significant differences in the bond strength between the three groups without thermocycling, but there was significant differences between Unicem$^{(R)}$ group and Valiolink II$^{(R)}$ group with thermocycling(P<.05). Conclusion: It has been shown to be clinically effective when the self-adhesive resin cements Unicem$^{(R)}$ and Biscem$^{(R)}$ were used instead of the etch-and-rinse resin cement Valiolink II$^{(R)}$ during the bonding of CAD/CAM ceramic inlay restorations with teeth.

• Journal of the korean academy of Pediatric Dentistry
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• v.33 no.2
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• pp.233-243
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• 2006

The aim of this study was to investigate the relationship between the C-factor and shrinkage strain values of composite resin and examine the strain values in different incremental filling techniques. Experiment consisted two aims. First, we compared with strain value in two different C-factors(3.7 and 1.0). Second, we examined the strain values in three different filling techniques. The results of the present study can be summarized as follows : 1. High C-factor groups showed higher contraction stress values than low C-factor groups at 900 sec after polymerization. 2. Hybrid resin showed higher contraction stress values than flowable resin in high C-factor cavities. But contraction stress was not revealed significant difference between hybrid resin and flowable resin in low C-factor cavities (P>0.05). 3. Bulk felling with hybrid resin(Group 1) showed high contraction stress and lining with flowable resin followed hybrid resin (Group 5) showed lower contraction stress. 4. Contraction stress were increased during 900 sec after polymerization in high C-factor groups but decreased gradually after 900 sec. 5. Low C-factor groups showed tight marginal seal between resin and cavity wall but high C-factor groups showed gaps formed between resin and cavity wall in part. On the basis above results, layering techniques in high C-factor cavity showed advantages in reducing contraction stress and gap formation between cavity wall and resin restoration.