• The korean journal of orthodontics
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• v.5 no.1
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• pp.64-68
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• 1975

• Journal of Technologic Dentistry
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• v.33 no.1
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• pp.47-54
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• 2011

Purpose: To investigate shear bonding strength between dental zirconia ceramics with different surface treatment and metal bracket. Methods: Zirconia ceramics(LAVA, 3M ESPE, USA) were divided to 4 groups according to their surface treatment; no surface treatment(G1), sand blasting(G2), silane coating(G3), and sand blasting+silane coating(G4). Specimens were bonded to metal bracket using resin bond($Transbond^{TM}XT$, 3M Unitek, USA). Shear bond strength was measured using universal test machine(3366 INSTRON. U.S.A) with cross head speed of 1 mm/min. Microstructural investigation for fracture surface was performed after shear test. Results: Shear bonding strengths of single surface treatment groups (G2 and G3) were higher than no treatment group(G1). Combined Treatment Group (G4) showed the highest shear bond strength of 9.15MPa. Microstructural observation shows that higher shear bonding strength was obtained when debonding was occurred at metal bracket/resin interface rather than zirconia ceramic/resin interface. Conclusion: Surface treatment of zirconia is necessary to obtain higher bonding strength. Combined treatment can be more effective when surface the surfaces are kept clean and homogeneous.

• The korean journal of orthodontics
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• v.43 no.5
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• pp.235-241
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• 2013

Objective: The purpose of this study was to investigate whether extension of the custom base is necessary for enhancement of bond strength, by comparing the debonding forces and residual adhesives of 3 different lingual bracket systems. Methods: A total of 42 extracted upper premolars were randomly divided into 3 groups of 14 each for bonding with brackets having (1) a conventional limited resin custom base; (2) an extended gold alloy custom base: Incognito${TM}$; and (3) an extended resin custom base: KommonBase${TM}$. The bonding area was measured by scanning the bracket bases with a 3-dimensional digital scanner. The debonding force was measured with an Instron universal testing machine, which applied an occlusogingival shear force. Results: The mean debonding forces were 60.83 N (standard deviation [SD] 10.12), 69.29 N (SD 9.59), and 104.35 N (SD17.84) for the limited resin custom base, extended gold alloy custom base, and extended resin custom base, respectively. The debonding force observed with the extended resin custom base was significantly different from that observed with the other bases. In addition, the adhesive remnant index was significantly higher with the extended gold alloy custom base. Conclusions: All 3 custom-base lingual brackets can withstand occlusal and orthodontic forces. We conclude that effective bonding of lingual brackets can be obtained without extension of the custom base.

• The korean journal of orthodontics
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• v.45 no.6
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• pp.299-307
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• 2015

Objective: The aims of this study were to compare the shear bond strength between orthodontic metal brackets and glazed zirconia using different types of primer before applying resin cement and to determine which primer was more effective. Methods: Zirconia blocks were milled and embedded in acrylic resin and randomly assigned to one of four groups: nonglazed zirconia with sandblasting and zirconia primer (NZ); glazed zirconia with sandblasting, etching, and zirconia primer (GZ); glazed zirconia with sandblasting, etching, and porcelain primer (GP); and glazed zirconia with sandblasting, etching, zirconia primer, and porcelain primer (GZP). A stainless steel metal bracket was bonded to each target surface with resin cement, and all specimens underwent thermal cycling. The shear bond strength of the specimens was measured by a universal testing machine. A scanning electron microscope, three-dimensional optical surface-profiler, and stereoscopic microscope were used to image the zirconia surfaces. The data were analyzed with one-way analyses of variance and the Fisher exact test. Results: Group GZ showed significantly lower shear bond strength than did the other groups. No statistically significant differences were found among groups NZ, GP, and GZP. All specimens in group GZ showed adhesive failure between the zirconia and resin cement. In groups NZ and GP, bonding failed at the interface between the resin cement and bracket base or showed complex adhesive and cohesive failure. Conclusions: Porcelain primer is the more appropriate choice for bonding a metal bracket to the surface of a full-contour glazed zirconia crown with resin cement.

• The korean journal of orthodontics
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• v.31 no.2 s.85
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• pp.261-270
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• 2001

The purpose of this study was to evaluate the clinical usefulness of plasma arc light which can reduce the curing time dramatically compared by shear bond strengths and failure patterns of the brackets bonded with visible light in direct bracket bonding. Some kinds of brackets were bonded with the Transbond$^{\circledR}$ to the human premolars which were embedded in the resin blocks according to the various conditions. After bonding, the shear bond strength was tested by Instron universal testing machine and in addition , the amount of residual adhesive remaining on the tooth after debonding was measured by the stereoscope and assessed with adhesive remnant index(ARI). The results were as follows : 1. When plasma arc light was used for bonding the brackets, the shear bond strength was clinically sufficient in both metal and ceramic brackets, but resin brackets showed significantly lower bond strength but which was clinically useful. 2. When metal brackets were bonded using visible light, there was no significant difference in shear bond strength due to the light-curing time and the bond strength was clinically sufficient. 3. When the adhesive failure patterns of brackets bonded with plasma arc light were observed by using the adhesive remnant index, the bond failure of the metal and resin bracket occurred more frequently at bracket-adhesive interface but the failure of the ceramic bracket occurred more frequently at enamel-adhesive interface. 4. There was no statistically significant difference of the shear bond strength and adhesive failure pattern between metal bracket bonded for 2 seconds by curing with plasma arc light and 10 seconds by curing with visible light. 6. When metal brackets were bonded using plasma arc light, the shear bond strength decreased as the distance from the light source increased. The above results suggest that plasma arc light can be clinically useful for bonding the brackets without fear of the decrease of the shear bond strength.

• The korean journal of orthodontics
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• v.51 no.6
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• pp.375-386
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• 2021

Objective: To evaluate the accuracy of a one-piece bracket jig system fabricated using computer-aided design and manufacturing (CAD/CAM) by employing three-dimensional (3D) digital superimposition. Methods: This in vitro study included 226 anterior teeth selected from 20 patients undergoing orthodontic treatment. Bracket position errors from each of the 40 arches were analyzed quantitatively via 3D digital superimposition (best-fit algorithm) of the virtual bracket and actual bracket after indirect bonding, after accounting for possible variables that may affect accuracy, such as crowding and presence of the resin base. Results: The device could transfer the bracket accurately to the desired position of the patient's dentition within a clinically acceptable range of ± 0.05 mm and 2.0° for linear and angular measurements, respectively. The average linear measurements ranged from 0.029 to 0.101 mm. Among the angular measurements, rotation values showed the least deviation and ranged from 0.396° to 0.623°. Directional bias was pronounced in the vertical direction, and many brackets were bonded toward the occlusal surface. However, no statistical difference was found for the three angular measurement values (torque, angulation, and rotation) in any of the groups classified according to crowding. When the teeth were moderately crowded, the mesio-distal, bucco-lingual, and rotation measurement values were affected by the presence of the resin base. Conclusions: The characteristics of the CAD/CAM one-piece jig system were demonstrated according to the influencing factors, and the transfer accuracy was verified to be within a clinically acceptable level for the indirect bracket bonding of anterior teeth.

• The korean journal of orthodontics
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• v.28 no.4 s.69
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• pp.659-668
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• 1998

The purpose of this study was to evaluate the possibility of the decrease of bond strength due to increased thickness of resin base in indirect bracket bonding technique. Metal brackets were bonded to the resin blocks involving bovine lower incisors and the thickness of resin bases was increased by increments of 0.5 mm from 0.0 mm to 2.0 mm. They were divided into two groups, one group is that the thickness of resin base was increased but the loading point from the tooth surface was maintained constantly, the other group is that the loading point from the tooth surface and the resin base thickness were increased concomitantly. The shear bond strength was tested on universal testing machine and the failure patterns were assessed with the adhesive remnant index(ARI). The results were as follows: 1. When the distance from the tooth surface to the loading point was maintained constantly, shear bond strength was increased significantly according to the decrease of distance from the bracket base to the loading point and the increase of resin base thickness. 2. When the distance from the tooth surface to the loading point and the resin base thickness were increased concomitantly, shear bond strength was decreased according to the increase of resin base thickness but significant differences were ignorable. 3. There were no significant differences in ARI scores according to the change in the thickness of resin base. The results of the present study indicated that shear bond strength was not much affected by the thickness of resin base, whereas was decreased according to the increase of distance from bracket base to the loading point.

• The korean journal of orthodontics
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• v.28 no.2 s.67
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• pp.277-284
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• 1998

The purpose of this study was to evaluate the propriety of making use of the light-cured resin base in indirect bracket bonding technique by study of shear bond strength and failure patterns according to the material of resin base. Metal brackets were bonded to the stone models of specimens involving bovine lower incisor with chemical-cured(Excel), light-cured(Light-Bond) and thermal-cured(Therma-Cure) resin. They were transferred to the specimens and bonded using sealant. The shear bond strength was tested on Instron. After bracket removal, the bracket base was examined and assessed with the adhesive remnant index(ARI). The results were as follows : 1. No significant differences in shear bond strength were found among the three groups (P>0.05). 2. No significant differences in ARI score were found among the three groups (P>0.05). The above results suggest that light-cured resin base in addition to chemical-cured and thermal-cured resin bases is useful in the indirect bonding technique.

• The korean journal of orthodontics
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• v.28 no.5 s.70
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• pp.681-688
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• 1998

The purpose of this study was to evaluate the effects of the surface treatments of resin bases in indirect bracket bonding technique by study of shear bond strengths and failure patterns. Ninety metal brackets were bonded to the stone models of specimens involving bovine lower incisor with light-cured adhesive(Light-Bond). After removal of brackets with the resin base from the stone models, the surfaces of resin bases in thirty brackets were treated with Plastic Conditioner and the surfaces of resin bases in another thirty brackets were treated with sandblaster and the remaining thirty brackets were served as controls. All brackets were transferred to the specimens and bonded using sealant. The shear bond strength was tested on universal testing machine, and failure pattern was assessed with the adhesive remnant index(ARI). The results were as follows: 1. Surface treatments of resin bases with Plastic Conditioner or sandblasting showed statistically higher shear bond strengths than no treatment group. 2. No significant difference in shear bond strength was found between Plastic Conditioner treatment and sandblasting treatment groups. 3. No significant difference in ARI scores was found among the three groups. 4. As the result of correlation analysis between shear bond strengths and hnl scores, failure at adhesive/bracket base interface tends to increase when the shear bond strength was high, but it was not significant statistically. The above results suggest that improvement of bond strength can be obtained by surface treatment of resin base in the indirect bonding technique.

• The korean journal of orthodontics
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• v.20 no.1
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• pp.103-110
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• 1990

Metal brackets were recycled by variable methods for economic reason. Such recycling methods had a great effect on bracket slot width and bonding strength. Therefore, the recycling methods that don't change the properties of original bracket were suggested. In this study, debonded brackets were recycled with 30 kinds of solvents and bracket surfaces were examined by S.E.M. (Super IIIA, ISI International Scientific Instruments, Japan) and Stero Microscope (Sz-Tr, Olympus Tokyo, Japan) methods. The following results were obtained. 1. Thermosetting resin adhesives (eq. $Monolok^{(R)}$, $Concise^{(R)}$) were swelled most in sulfuric acid (assays 95%) and slightly in alcohol groups. 2. The solvent was exchanged every 24 hours during the brackets were recycled with sulfuric acid (assays 95%). As the passage of time, the adhesives were removed more clearly, and after 72 hours adhesives were nearly detached from bracket base. 3. Chemical recycled metal bracket surface showed no irregular structure by S.E.M. method.