• The Journal of Korean Academy of Prosthodontics
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• v.38 no.1
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• pp.1-11
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• 2000

Relining and rebasing are essential for long-term success and oral health in removable prosthodontics. Major features of failures between metal base and relining resins are adhesive failure due to lack of chemical bonding. The purpose of this study was to find a better metal primer and metal surface treatment method that enhance the bonding strength with relining resin materials. The surfaces of ticonium alloys were treated with $25{\mu}m$ sandblasting (Group A), stone wheel(Group B), stone wheel and EZ oxisor(Group C), $75{\mu}m$ sandblasting(Group D) and EZ oxisor application after $75{\mu}m$ sandblasting(Group E). They were subdivided into no primer application (Group I), MR bond application(Group II) and Metafast bonding liner (Group III). Then specimens were completed though being bonded with relining resins. The specimens were stored in $38^{\circ}C$ water for 48 hours and tensile strength was measured using the universal testing machine. The results were as follows, 1. Primer application groups showed higher bond strength than no primer application group(p<0.05). 2. In comparison with primer application groups, MR bond group showed higher bond strength than Meta fast bonding liner application group(p<0.05). 3. In comparison with surface treatment methods, Bond strengths of group A and B were significantly different with group C, D, and E, and group C were significantly different with group D, and E in no primer application group()(0.05). In primer application groups, group A, B, C were significantly different with group D and E(p<0.05). According to results of this study, Metal primer application and metal surface roughening were considered to be advantageous for relining of metal base dentures.

• The Journal of Korean Academy of Prosthodontics
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• v.39 no.4
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• pp.417-432
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• 2001

The pcf metal primers on the bond strength and durability of 4-META/MMA-TBB resins adhered to an Au-Ag-Pd alloy. For this study, the specimens were divided into 8 groups as follows: Thermocyle 0 : (1) control group : sandblast, (2) Group I : sandblast + Cesead Opaque Primer; (3) Group II : sandblast + Metal Primer; (4) Group III : sandblast + V-Primer; Thermocyle 10,000 (5) control sandblast: (6) Group I : sandblast + Cesead Opaque Primer: (7) Group II : sandblast + Metal Primer; (8) Group III sandblast + V-Primer. The shear bond strength was determined using an Instron were observed with the use of scanning electron microscope. Finally, the strengths of bonded joints were evaluated with regard to their adherence energy using a wedge test. The results obtained were as follows ; (1) The shear bond strength of 4-META/MMA-TBB resin to the Au-Ag-Pd alloy was significantly improved in all the groups treated with the primers (p<0.05). (2) Regardless of the adhesive primers used, a significant difference was observed in the bond strength of the thermocycle 0 groups and 10,000 groups (p<0.05). (3) Both before and after thermocycling, the strongest bond strength between the resin an the alloy was obtained after treatment with a metal primer containing MEPS (p<0.05). (4) In the wedge test, the adherence energies of the control group and Group III decreased more rapidly than those of Group I and II during the 2nd day of storage in water.

• The Journal of Korean Academy of Prosthodontics
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• v.27 no.2
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• pp.101-121
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• 1989

This study investigated the effects of Silicoating procedure on the tensile bond strength of resin-bonded prostheses. The Rexillium III specimens were treated with electrochemical etching and Silicoating procedure, followed by thermocycling and the NNB, Pors-on 4, and Degudent-U specimens were treated with Silicoating procedure. The specimens were debonded in tension with a Tensilon machine. Also, all specimens were observed with SEM, concentration of Si elements was analyzed with EPMA, and the mode of failure was recorded. The results of this study were obtained as follows: 1. In the Rexillium III specimens, the tensile bond strength of the Silicoated specimens was higher than that of the electrochemically etched specimens, and significant differences were observed (P<0.05). 2. The tensile bond strength of electrochemically etched Rexillium III specimens, significant differences were observed between the thermocycled and nonthermocycled specimens (P<0.05), but no significant differences were observed in the Silicoated specimens (P>0.05). 3. The tensile bond strength of the Silicoated specimens decreased NNB, Pors-on 4, Rexillium III, and Degudent-U in that order named. 4. Unlike the electrochemically etched specimens, the Silicoated specimens showed gap-free metal-resin interfaces with SEM. 5. Compared to the electrochemically etched specimens, the Silicoated specimens showed higher concentration of Si elements at the metal-resin interfaces and resin cement. 6. Photographic evaluation (X2) of the fractured sites revealed mainly cohesive failures with the Silicoated specimens, and adhesive failures with the electrochemically etched specimens.

• Journal of the korean academy of Pediatric Dentistry
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• v.32 no.2
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• pp.191-199
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• 2005

This study was experienced in order to obtain the shear bond strength of orthodontic bracket adhesives under the blood contamination that can be occurred during the procedure of bracket bonding under window opening surgery. As a result of this study, shear bond strength of all glass ionomer groups were lower than resin cement groups. However, the strength of uncontaminated and post-contaminated group of glass ionomer was strong enough to perform an orthodontic forced eruption. This study revealed that during a window opening surgery, glass ionomer without etching procedure is available in order to bond a bracket if surface of teeth is not pre-contaminated by blood before the adhesive application. Both simple procedure and less adhesives remnant after bonding failure could make light-cured glass ionomer cement the ultimate choice for racket bonding.

• The Journal of Korean Academy of Prosthodontics
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• v.38 no.4
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• pp.500-509
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• 2000

In general, the three major oral functions of edentulous patients-mastication, phonation, esthetics-can be rehabilitated by the complete dentures, and both the resin based complete denture and the metal based complete denture are commonly used by many clinicians today. For the sake of many advantages such as the excellent thermal conductivity, low volumetric change, high strength, low risk of fracture and the better patient's adaptation, the metal based complete dentures are indicated to the several cases. But, there are common failures of these type of dentures mainly by the fracture or the debonding between the resin structures and the metal frameworks which is caused by the discrepancies of the flexural strength and the coefficient of thermal expansion. This is aggravated by the water contamination of the interface when exposed to the oral environment and results in the failure of complete denture treatment. So, the purpose of this study is to compare the bond strength and the fracture patterns of the gold alloy based and the Co-Cr alloy based complete dentures using the PMMA resins and the 4-META adhesive resins. The results of this study were as follows. 1. Both to the PMMA resin and the 4-META resin, the flexural bond strength of gold alloy is lower than that of Co-Cr alloy(P<0.05) 2. To the Co-Cr alloy, the bond strength of the 4-META resin is significantly higher than that of PMMA resin(P<0.05). 3. The flexural strength of the group with the mechanical retention form is significantly higher than that of the group without retention form(P<0.05). 4. Comparing with the other groups, the fracture patterns of the group 3 are quite different from the group 1,2,5.

• The Journal of Korean Academy of Prosthodontics
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• v.43 no.2
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• pp.149-157
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• 2005

Statement of problem. Dental ceramics exhibit excellent esthetic property, compressive strength, chemical durability biocompatibility and translucency. However, it suffers from inherent brittle fractures. Various techniques and materials for intraoral porcelain repair has been suggested. Purpose. This study is to compare the tensile bond strength of four commonly used porcelain repair systems (Vivadent, Bisco, Ulttadent, Voco) and to insure the best system for the clinical application to the fractured porcelain. Materials and methods. A total of fifty specimens were fabricated. Specimens were stored in $37^{\circ}C$ distilled water for 7 days and thermocycling was performed(1000 cycles), and subjected to a tensile force parallel to the repair resin and porcelain interface by use of an Universal Testing Machine. Result. 1. Voco showed the highest tensile bond strength. In decreasing order, the tensile bond strength of the other materials was as follows : Ultradent, Bisco, Vivadent. 2. There was a statistically significant difference between the porcelain repair systems(Voco, Ultradent > Bisco, Yivadent) (p<0.05). 3. SEM examination of prepared porcelain surfaces revealed that the surface treated with Voco showed brittle fracture. However, Ultradent, Bisco and Vivadent showed ductile fracture. 4. All specimens treated with four porcelain repair systems showed adhesive failure between porcelain and composite resin.

• The Journal of Advanced Prosthodontics
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• v.4 no.4
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• pp.192-196
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• 2012

PURPOSE. The purpose of this study was to evaluate the effect of provisional cement removal by different dentin cleaning protocols (dental explorer, pumice, cleaning bur, Er:YAG laser) on the shear bond strength between ceramic and dentin. MATERIALS AND METHODS. In total, 36 caries-free unrestored human third molars were selected as tooth specimens. Provisional restorations were fabricated and cemented with eugenol-free provisional cement. Then, disc-shaped ceramic specimens were fabricated and randomly assigned to four groups of dentin cleaning protocols (n = 9). Group 1 (control): Provisional cements were mechanically removed with a dental explorer. Group 2: The dentin surfaces were treated with a cleaning brush with pumice Group 3: The dentin surfaces were treated with a cleaning bur. Group 4: The provisional cements were removed by an Er:YAG laser. Self-adhesive luting cement was used to bond ceramic discs to dentin surfaces. Shear bond strength (SBS) was measured using a universal testing machine at a 0.05 mm/min crosshead speed. The data were analyzed using a Kolmogorov Smirnov, One-way ANOVA and Tukey HSD tests to perform multiple comparisons (${\alpha}$=0.05). RESULTS. The dentin cleaning methods did not significantly affect the SBS of ceramic discs to dentin as follows: dental explorer, pumice, cleaning bur, and Er:YAG laser. CONCLUSION. The use of different cleaning protocols did not affect the SBS between dentin and ceramic surfaces.

• Restorative Dentistry and Endodontics
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• v.19 no.1
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• pp.114-123
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• 1994

The purpose of this study was to examine the shear bond strength of resin-enamel bond formed at specific time intervals after the termination ov vital bleaching. A total of 72 human extracted maxillary premolars were divided into nine groups : untreated control (group 1) ; enamel treated with 35% hydrogen peroxide(group 2, 3, 4, 5) ; and enamel reated with 15% carbamide peroxide gel (group 6, 7, 8, 9). After the treatment with 35% hydrogen peroxide for 2 hours and 15% carbamide peroxide for 24 hours, adhesion of a resin to bleached enamel was formed at 1 hour (group 2, 6) and 24 hours(group 3, 7) ; 3days(group 4, 8) and 7 days(group 5, 9) post-termination of bleaching treatment. A $3{\times}3mm$ mold was filled with Scotchbond Multi-Purpose and Z100. After 24 hours later, the specimens were shear-tested at crosshead speed 1mm/min and analyzed statistically. Fractured specimens from group 1,2, 6 were gold-coated with Eiko ion coater and observed under Scanning electron microscope at 25KV. The following results results were obtained : 1. Bonds formed at 1 hour post-termination of 35 % hydrogen peroxide(P<0.01) and 15 % carbamide peroxide bleaching treatment groups(P<0.05) showed significantly lower shear bond strength than untreated group. 2. Bonds formed at 24 hours, 3 days and 7 days post-termination of 35% hydrogen peroxide and 15 % carbamide peroxide bleaching treatment groups showed no significant differences in shear bond strength with untreated group(p>0.05). 3. SEM examinations of the untreated fracture specimen indicated cohesive fracture within enamel and exposed enamel prisms, but the bleached fracture specimens indicated adhesive fracture.

• Restorative Dentistry and Endodontics
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• v.46 no.3
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• pp.36.1-36.11
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• 2021

Objectives: This study aimed to evaluate Emblica officinalis (Indian gooseberry or amla) as an acid etchant and matrix metalloproteinase (MMP) inhibitor, and to compare its effect on the microshear bond strength of composite resin with orthophosphoric acid (OPA) and 2% chlorhexidine (CHX) as an acid etchant and MMP inhibitor, respectively. Materials and Methods: The etching effect and MMP-inhibiting action of amla on dentin samples were confirmed by scanning electron microscopy (SEM) and gelatin zymography, respectively. Dentinal slabs (3 mm thick) from 80 extracted human molars were divided into 10 and 20 samples to form 2 control groups and 3 experimental groups. Groups 1, 2, and 4 were etched with OPA and groups 3 and 5 with amla juice. An MMP inhibitor was then applied: CHX for group 2 and amla extract for groups 4 and 5. Groups 1 and 3 received no MMP inhibitor. All specimens received a standardized bonding protocol and composite resin build-up, and were subjected to microshear bond strength testing. The force at which the fracture occurred was recorded and statistically analyzed. Results: Amla juice had a similar etching effect as a self-etch adhesive in SEM and 100% amla extract was found to inhibit MMP-9 by gelatin zymography. The microshear bond strength values of amla were lower than those obtained for OPA and CHX, but the difference was not statistically significant. Conclusions: Amla has a promising role as an acid etchant and MMP inhibitor, but further studies are necessary to substantiate its efficacy.

• Journal of the korean academy of Pediatric Dentistry
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• v.26 no.2
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• pp.284-295
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• 1999

The purpose of this study was to measure and analyze the bond strength of bonded amalgam using dental adhesives and to compare this with light-curing composite resin. Sections 8mm in diameter were punched out from the labial surface of bovine anterior teeth. These were embedded in clear acrylic resin blocks with labial surface facing out. 55 specimens were made for enamel and dentin each. After dividing these into 5 groups, group 1: Superbond C&B, group 2: Panavia 21, group 3: All-Bond 2, group 4: Fuji I Glass Ionomer Luting Cement, group 5: Scotchbond Multi-Purpose(Restorative Z-100), molds with holes of 6.3mm in diameter and 1.5mm in depth were placed over the specimens. The exposed tooth surfaces were treated with adhesives and the molds were filled with amalgam. In group 5, the mold was filled with composite resin and light-cured for 40 seconds. The author measured all specimens for bond strength 24 hours after amalgam filing and analyzed fracture surfaces. The following results were obtained: 1. Among the dentin groups, groups 1, 2 and 4 showed significantly lower bond strength compared with group 5(P<0.05). 2. Among the enamel groups, group 4 showed significantly lower bond strength compared with group 5(P<0.05). 3. In group 2, 2D showed significantly lower bond strength compared with group 2E(P<0.05). Other adhesives showed no such differences in bond strength between dentin and enamel(P>0.05). 4. Cohesive failure was observed in groups 1E and 5D, while mixed failure was seen in groups 1 and 5. Only adhesive failures were noted in groups 2, 3, 4.