• The korean journal of orthodontics
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• v.35 no.6 s.113
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• pp.433-442
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• 2005

The purpose of this study was to evaluate and compare the shear bond strength of orthodontic brackets depending on the variety of adhesives and whether saliva exists, by using self-etching primer (SEP). Groups were divided according to the type of adhesive into resin adhesive (Trans bond XT) and resin-modified glass ionomer cement (Fuji Ortho LC). One group of resin adhesive used XT primer after etching with 37% phosphoric acid, and the other group used self-etching primer. One group of resin-modified glass ionomer cement only used etching for bonding, and the other group used SEP. Each of the groups were also classified by whether saliva was contaminated or not. and then the shear bond strength was measured. The results showed that when using resin adhesive, the shear bond strength of SEP was lower than the XT primer. In the resin-modified glass ionomer cement groups, the shear bond strength which depends on the priming method, did not have a meaningful difference statistically When saliva was contaminated, the group which used SEP, regardless of the adhesive variety, had a greater shear bond strength than the normal priming group. From these results, SEP showed a shear bond strength that is possible to be used clinically, regardless of the adhesive variety. It can especially be clinically useful to use SEP to bond brackets even on tooth surfaces contaminated with saliva, because it offers the appropriate bonding strength as well as shorter treatment time and easy application.

• Journal of dental hygiene science
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• v.18 no.4
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• pp.218-226
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• 2018

The aim of this study was to compare fluoride release and surface changes according to different orthodontic bracket adhesives the application of fluoride products. We used non-fluoridated composite resin Transbond fluoridated composite resins Blugloo and LightBond, resin-modified glass ionomer Rely $X^{TM}$ Luting 2, and conventional glass ionomer Fuji $I^{(R)}$. Fluoride release of five orthodontic bracket adhesives and fluoride release ability after application of three fluoride products (1.23% acidulated phosphate fluoride gel, Tooth Mousse $Plus^{(R)}$, Fluor Protector, and a toothbrush with sodium fluoride-containing toothpaste) were measured using a fluoride electrode that was connected to an ion analyzer. After 4 weeks of fluoride application, the surface roughness and surface morphology were examined using a surface roughness tester and field emission scanning electron microscopy. The amounts of fluoride release were observed not only on application of Tooth Mousse $Plus^{(R)}$ and Fluor Protector on resin-modified glass ionomer Rely $X^{TM}$ Luting 2 and Fuji $I^{(R)}$, but also during tooth brushing using fluoride-containing toothpaste. After application of Tooth Mousse $Plus^{(R)}$, except Transbond XT, the surface roughness increased, and all orthodontic adhesives showed a partial drop of micro-particle filler. On application of 1.23% acidulated phosphate fluoride gel on all orthodontic bracket adhesives, their surface roughness increased. To bond the orthodontic bracket, resin-modified glass ionomer Rely $X^{TM}$ Luting 2 and Fuji $I^{(R)}$ adhesives are highly recommended if the amount of fluoride release is considered to confer a preventative effect on dental caries, and among the fluoride products, Tooth Mousse $Plus^{(R)}$ and Fluor Protector are better than 1.23% acidulated phosphate fluoride gel, and these are expected to prevent dental caries even during tooth brushing with fluoride-containing toothpaste.

• The korean journal of orthodontics
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• v.29 no.6 s.77
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• pp.673-688
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• 1999

This study was conducted in order to analyze the mechanical characteristics of multiloop edgewise archwire (MEAW). The purposes were 1) to compare load deflection rate (LDR) of MEAW with that of various other arch wires in the individual interbracket span, 2) to compare the wire stiffness in the interbracket span with that in the multi-L-loop region (the span from distal border of the bracket of the lateral incisor to the mesial border of the buccal tube of the second molar), and 3) to verify the experimental results with theoretically derived formula. The single L-loops of five different horizontal lengths and multi-L-loops for the upper and lower arches were made out of .$016\times.022$ permachrome stainless steel wire. Straight segment of plain stainless steel, TMA and NiTi wire of the same dimension were prepared. The LDR was measured using Instron model 4466 with the load cell of 50N capacity at cross head speed of 1.0mm/min, and maximum deflection of 1.0mm. Five specimens were tested under each experimental condition. The wire stiffness number for each interbracket region and multi-L-loop region was calculated from the LDR and the interbracket spans. By dividing the theoretical model of multi-L-loop into 35 linear segments, the energy stored in each segment was obtained. Then the LDR and wire stiffness of single L-loop and multi-L-loop were calculated and compared. The findings were as follows : 1) The average LDR of MEAW in the individual interbracket region was 1/1.53 of that of the NiTi,1/2.47 of TMA and 1/5.16 of the plain stainless steel wire. 2) The wire stiffness of MEAW in the multi-L-loop region was 1.53 times larger than that in the interbracket region, and the LDR was almost twice as large as that of NiTi in that region. 3) According to the theoretically derived equation, the wire stiffness of the single L-loop was lower than that of multi-L-loop. The results of this study suggest that MEAW has the unique mechanical Property which could allow individual tooth movement and transmit elastic force effectively through the entire arch wire.

• The korean journal of orthodontics
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• v.25 no.1 s.48
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• pp.55-72
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• 1995

The purpose of this study is to evaluate the effects of mechanical and thermal fatigue on the shear bond strength(SBS) in orthodontic brackets bonded to human premolars with chemically cured adhesive(Mono-$Lok^2$, Rocky Mountain Orthodontics). Two types of metal brackets (Ormesh, Microloc) and three types of ceramic brackets (Fascination, Starfire, Transcend 2000) were used in this study. The $10^6$ loadcycles of $|7.4{\times}10{^2}sin2{\pi}ft|g{\cdot}cm$ and the 1,000 thermocycles of 15 second dwell time each in $5^{\circ}C\;and\;55^{\circ}C$ baths were acturated as mechanical and thermal fatigue stress, and SBS were measured after each fatigue test. The fracture sites were examined by stereoscope and scanning electron microscope. The results obtained were summarized as follows, 1. In static shear bond test, Fascination brackets showed the maximum SBS($20.78\pm3.45$ MPa) and Microloc brackets showed the minimum SBS($14.88\pm3.10$ MPa). Fascination and Starfire brackets showed significantly greater SBS than Microloc brackets(P<0.05). 2. In mechanical fatigue test, Fascination brackets showed the maximum SBS ($20.19\pm3.45$ MPa) and Starfire brackets showed the minimum SBS($9.10\pm8.33$ MPa). The SBS or Transcend 2000 brackets(P<0.01) and Starfire brackets(P<0.05) significantly decreased after $10^6$ loadcycles. 3. In thermocycling test, Ormesh brackets showed the maximum SBS ($19.36\pm2.76$ MPa) and Starfire brackets showed the minimum SBS($11.94\pm6.86$ MPa). The SBS of Transcend 2000(P<0.01), Microloc and Starfire brackets(P<0.05) significantly decreased after $10^3$ thermocycles. 4. Failure sites of thermocycling groups were similar to those of static groups but after mechanical fatigue test, Ormesh and Transcend 2000 brackets failed at the bracket/resin interface and Microloc brackets failed within adhesive. Facination brackets failed at the enamel/resin interface irrespective of experimental condition.

• Journal of Dental Rehabilitation and Applied Science
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• v.38 no.4
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• pp.189-195
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• 2022

Purpose: For orthodontic bracket bonding, light curing resin cement is widely used because the process is convenient, and it can be polymerized at the desired time. This study compared the difference of bonding strength of orthodontic resin cement according to storage condition. Materials and Methods: After acid etching the bovine enamel surface with 37% phosphoric acid, 15 orthodontic brackets for mandible incisors were bonded with Ortho Connect and Orthomite LC according to following three conditions; 1) Immediate after 4℃ refrigeration for 3 months (IR), 2) One day room temperature after 4℃ refrigeration for 3 months (OR), 3) Room temperature for 3 months (RT). The shear bond strength was measured with a universal material tester and failure pattern of the specimen was observed. Two-way ANOVA and One-way ANOVA were used at the 95% significance level. Results: Ortho Connect that was applied immediately after refrigeration showed the maximum shear bond strength. Orthomite that was applied immediately after refrigeration showed the lowest shear bond strength, and the group stored at room temperature for three months showed the highest shear bond strength, and the difference between the two groups was significant. Conclusion: Ortho Connect can be used without worrying about bond strength even if it is used immediately after refrigeration, but Orthomite should be kept at room temperature sufficiently after refrigeration.

• The korean journal of orthodontics
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• v.23 no.2 s.41
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• pp.147-163
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• 1993

The purpose of this stuy was to evaluated the cytotoxicity of brackets which were recycled thermally or chemically. New brackets and used brackets which had been in mouth for at least 2years were used as samples and human gingival cell culture and agar overlay technique was used to evaluate the cytotoxicity. From the experiment the following results were obtained : 1. New brackets in the as received state showed mild cytotoxicity. 2. Thermally recycled brackets except the used bracket not electropolished showed moderate cytotoxicity and among them new brackets showed greater cytotoxicity than used ones. 3. Used brackets which were thermally recycled without electropolishing showed mild cytotoxicity. 4. Among thermally recycled brackets, electropolished brackets showed greater cytotoxicity than not electro-polished ones. 5. Chemically recycled brackets showed moderate cytotoxicity, and among them, new brackets appeared to be more cytotoxic than used ones.

• The korean journal of orthodontics
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• v.34 no.6 s.107
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• pp.544-554
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• 2004

A device called incisor inclination indicator to control the axial inclinations of the incisors in the diagnostic setup is introduced. It is used to control the retraction of the maxillary and mandibular incisors. In this article, we describe the use of the incisor inclination indicator to prescribe adequate torque into the anterior lingual brackets and evaluate the results of treatment in a bimaxillary dentoalveolar protrusion case that underwent orthodontic treatment with the pretorqued anterior lingual brackets. Retraction of the maxillary and mandibular incisors was achieved with careful control of the axial inclination. It is indicated that the use of the incisor inclination indicator is an effective adjunctive laboratory procedure for anterior torque control during retraction in lingual orthodontic treatment.

• The korean journal of orthodontics
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• v.33 no.5 s.100
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• pp.381-389
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• 2003

Mutans streptococci is the major causative factor in dental caries. Especially, orthodontic patients with fixed appliance are a risk group for dental caries. Because fixed appliances attached on teeth may change the environment of dental plaque, the enamel decalcification or dental caries around the bracket and band is a major side effect of orthodontic treatmet. The aim of this study was to search plant extracts that have antimicrobial effect on mutans streptococci. Seed-extract of Casia torn were prepared with ethanol and CHMC-2032, the leaf-extracts from Camellia sinensis extract, was obtained extract, 2 type strains and 20 clinical isolates of mutans streptococci isolated from the interface between orthodontic brackets and tooth surfaces in the orthodontic patients were used in this study. The minimal inhibitory concentration of CHMC-2032 was 5mg/ml on the S. mutans KCTC 3065, S. sobrinus KCTC 3088, and 8 clinical isolates of S. sobrinus. However, there was no antibacterial effect of seed-extract of C. tora on mutans streptococci. These data suggest that green tea nay be more effective than the tea Prepared from C tora In the prevention of enamel decalcification or dental caries around brackets.

• The korean journal of orthodontics
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• v.29 no.4 s.75
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• pp.445-456
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• 1999

As a result of increased education and communication, the field of orthodontics has recently been expanded to include a greater number of adult treatment procedures. With this increased demand for adult orthodontic treatment, a problem that frequently arises is the placement of appliances on teeth restored with porcelain. But conventional acid-etching is ineffective in the preparation of porcelain surface for mechanical retention of orthodontic attachments. Also, it is possible to damage on porcelain. The purpose of this study was to evaluate the effect of composite bonding materials and the porcelain surface treatment methods on shear bond strength, and to observe the porcelain fracture rates. To accomplish this purpose, this study was carried out with feldsphatic porcelain, Ceram II. Porcelain surface treatment methods were divided into intact glazed porcelain which had not treatment and surface roughening. Surface roughening by etching with Hydroluoric acid(HF), sandblasting with Microetcher II and compound treatment with etching and sandblasting. Bonding materials were Ortho-two and Transbond. All porcelain specimens were applicated with porcelain primer. 1. In comparision according to porcelain surface treatment, surface roughening groups by HF etching and sandblasting had higher shear bond than intact group. No significant difference was found in Transbond group. 2. Ortho-two group had the higher shear bond strength than that of Transbond group in B:.u etching and sandblasting. 3. E(Transbond. Intact)group had the lowest shear bond strength in all experimental group. The bond strength was higher than clinically successful bond strength. 4. Non-treated group had very higher porcelain rates than treated group. 5. This study indicates that porcelain surface-roughening may not be necessary to attachment of orthodontic brackets to porcelain surfaces.

• The korean journal of orthodontics
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• v.35 no.1 s.108
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• pp.43-50
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• 2005

The purpose of this study was to evaluate the effects of a sealant resin on enamel demineralization In orthodontic bracket bonding. The forty eight extracted sound bovine teeth were subdivided into four groups and treated with Phase II (Reliance, itasca. III) on the surface Group 1 was not treated. Group 2 was acid etched with 37% phosphoric acid for 30 seconds. Group 3 was applied with sealant after acid etching. Group 4 was applied with resin paste after acid etching and sealant application. Each group was demineralized in artificial caries solution. Demineralized enamel depth was measured by confocal laser scanning microscopy. The results were as follows: the mean demineralized enamel depth was $47.4{\mu}m$. (Group 1), $61.8{\mu}m$ (Group 2), $13.9{\mu}m$ (Group 3). $8.2{\mu}m$ (Group 4) the demineralized enamel depth was increased in Group 2 than in Group 1 (p<0.05); the demineralized enamel depth was reduced in Group 3 than in Group 1 and Group 2 with statistically significant differences (p<0.05): and demineralization in Group 4 was very little. The results of the present study indicate that sealant application is useful for reducing enamel demineralization in orthodontic bracket bonding.