Các bước gắn mắc cài gián tiếp

en mắc cài

Gắn mắc cài gián tiếp là kỹ thuật không thể thiếu trong điều trị chỉnh nha mặt lưỡi

1.Begin with a good quality alginate impressions.
2. Immediately pour (to ensure dimensional accuracy) in Type IV dental stone
a. Using a stronger material than orthodontic plaster lessens the risk of teeth breaking off the model during impression separation. Successful indirect bonding obviously requires all teeth be intact.
b. Using a stronger material than orthodontic plaster also increases the likelyhood maintaining these models for the record (can make only one impression and use model both for the indirect bonding and as the record).
3. Trim models to allow full access to buccal and lingual tooth surfaces. Remove narrow crevices that often form on the lingual posterior of lower models and upper buccal to the second molars.
4. Revised: Allow models to dry then paint the buccal surfaces of the teeth (the anticipated bracket position) with light cured Quest model primer. Apply to only several teeth at a time and then cure immediately. Curing must be done immediately so that the stone does not absorb too much of the primer. The objective is to create a “glassy” coating of cured primer. This will prevent the model from absorbing the primer component of the composite adhesive used for applying brackets to the model. Without this coating, the stone will absorb the liquid component of the composite adhesive and cause it to dry out and become brittle (making positioning nearly impossible). The coating permits the brackets to be placed on the model and then stored indefinitely – doctor can position brackets when its convenient. Note: moisture insensitive primers contain a volatile component that absorbs more quickly than regular primers. Therefore, curing of these primers must occur immediately after application.
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5. Adhere brackets to model using Quest composite adhesive (Specially formulated for Quest by Reliance: the same adhesive is used for intraoral bonding procedures.)
6. Position brackets using Quest height gauges and establish the best “line of placement” (see vertical bracket placement guide). This is critical to achieving ideal bracket positioning. Gauge angulation will effect vertical position, therefore, gauge angulation should approximately parallel bracket slot (torque) to establish accurate height.
7. Remove excess composite adhesive from around bracket bases.
8. Lightly cure adhesive using regular light cure unit 2-3 seconds for metal brackets. Caution should be excercised when curing ceramic brackets. Too much curing will cause excess adhesion to the stone and cause damage to your model. For ceramic brackets, keep the curing light in motion and simply move across the arch at a moderate pace. The degree of cure will vary depending on intensity of light cure unit.
9. Apply Quest translucent tray material to occlusal side of brackets only. Be sure to coat the entire occlusal half with this material. Keep the dispensing tip in motion and slowly move across the entire arch in one stroke.
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10. Apply colored/opaque tray material to the gingival side of brackets. Be sure to inject into interproximal areas, cover the remaining exposed bracket surfaces entirely and .ll all voids surrounding the bracket bases.
11. Trim the inner tray material of excess as needed with a scalpel. Removing excess from the second molar (or third molar) area is important to achieved the least possible tray thickness.
12. Apply rigid thermoplastic Quest tray material using vacuum forming machine.
13. Cut the rigid tray material on the buccal side at the margin of the colored/opaque tray material and on the lingual side 3-5mm apical to the gingival margin.
14. Insert a scaler or cast removing instrument through the buccal/facial cut and through the rubbery tray material to access the brackets and break their bond to the model.
15. Be sure all bracket bonds are broken and then remove the tray from the model.
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16. Complete the light-curing of the composite adhesive on the bases and smooth the rough margins of the rigid tray material with an acrylic bur.
17. With an acrylic bur, trim the rigid tray component to relieve buccal/facial undercuts (this will ease removal from the mouth after intra-oral procedures)
18. Clean the bases of excess composite and stone particles/debris using brief micro-abrasion with 90-micron aluminum oxide (Only a brief micro-abrasion is needed. Do not attempt to completely remove composite from the bases – it is too time consuming and unnecessary.) Trays are ready for intra-oral procedures.
19. It is vital to thoroughly remove any calci.ed/adherent accumulation from buccal surface of molars, especially upper second molars. Always prepare molar surfaces by abrading surface with a bur to remove absolutely ensure a clean enamel surface. Follow with an application of oil-free pumice. Pumicing alone is inadequate and will lead to poor bond integrity. Doctor should verify that all enamel surfaces to be bonded are completely free of adherent plaque/debris.
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20. It is best to prepare trays completely prior to patient isolation. Apply Quest primer to all bracket bases then apply Quest composite adhesive to each bracket base. The Quest adhesive dispensor in designed to aid in the appication of precise quantities of adhesive. The author recommends coating half of the braket base with composite, and spreading it over the remaining base area with a primer moistened microBrush. This method prevents the application of too much adhesive. On molars, coat the entire bracket. A bit of excess is good in the posterior.
21. A good means of isolation is also vital. The Quest dry field system is the best method currently available, but can sometimes be frustrating. (The new isolation device radically simplifies and improves isolation for indirect bonding and will be available soon.)
22. To aid in isolation of the upper second molars trim a dry angle as need allow placement of the foil side against the buccal surface of the upper second molar. This keeps the wet cheek from laying against the enamel. Etch and prime can be done with the foil contacting the enamel. Then the tray can easily be slid in between the foil side and the enamel.
23. Following normal tooth surface preparation/etching proceudres. Enamel, etch 15-20 seconds with 37% phosphoric acid. When bonding to porcelain or metal, the author recommends Reliance materials and protocols for bonding. The Quest primer and composite may be substituted for other Reliance light cured composite adhesives in these protocols.
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24. Seat the tray immediately following enamel preparation and application of primer to the enamel surfaces. Immediate seating reduces the chance of moisture contamination.
25. After seating the tray, apply gentle localized pressure to the tray just prior to exposure with lightcure unit. Start curing at the second molars (the most posterior tooth) and use a mouth mirror to apply gently pressure to the buccal as the light cure unit tip applies occlusally directed pressure to the tray.
26. It is best to always apply pressure immediately prior to light exposure to ensure complete seating of the brackets and expulsion of excess adhesive.
27. Curing time depends upon the type of curing unit being used and the type of bracket. With the Optilux 501 unit, 30 seconds per metal bracket is sufficient. Use of high powered laser units will radically reduce curing time. More time may be required with less powerful units. Less time is needed when using ceramic brackets. More time should be allowed for curing metal brackets against porcelain or metal crowns.
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28. Remove the tray by first removing the clear thermoplastic rigid component, starting from the buccal of the second molars, leaving the inner rubbery portion in place. Then simply peel away the rubbery inner tray. (Don’t worry, it is not strong enough to pull the brackets off.)

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