Direct and Indirect Bonding Techniques

10.1055/b-0034-75536

Direct and Indirect Bonding Techniques

The following sections compare direct and indirect bonding techniques for self-ligating bracket systems. Indirect bonding has a number of distinct advantages for self-ligating systems, due to the demanding mechanical characteristics of the ligation mechanism itself ( Fig. 6.9 ).

Direct Bonding

The series of images in Fig. 6.10 illustrate the direct bonding technique in a step-by-step fashion.

CLINICAL PEARL

OptraGate check retractors (Ivoclar, Vivadent, available in several sizes) provide good visibility of the working field.

Advantages

There are no additional laboratory costs associated with this method. The positioning of the bracket is directly visible; residual surface adhesive can be removed immediately.

NOTE

Direct bonding of self-ligating brackets allows visualization and removal of excessive bonding agent, preventing subsequent interference with the ligation mechanism.

Disadvantages

The field of vision may be limited due to access problems, depending on the cheek retractor used, the extent of the patient’s mouth opening, and the tightness of the lips. This can be particularly difficult in the premolar and molar areas, and inaccuracies in bracket placement will require either compensatory bending for detailing and finishing, or repositioning of the brackets.

Fig. 6.9a–d Direct and indirect bonding. The advantage of indirect bonding is that brackets are positioned precisely according to vertical and horizontal orientation lines that are directly marked on the plaster cast. Visualization is unobstructed, and the bracket positions can be easily evaluated from all angles. The marks would have to be placed on the conditioned enamel surface, if the tooth surfaces were to be marked for direct bonding. a, c Direct bonding. b, d Indirect bonding.
Fig. 6.10a–l Direct bonding a, b Use of a cheek retractor to establish a dry field. c Conditioning of the enamel with phosphoric acid. The whole buccal enamel surface is etched to allow a sealant to be used to protect the enamel surface from decalcification. d Drying of the field shows the “frosted” appearance of the enamel and thus confirms the etching. e, f Marking of the reference points for bonding using a Boley gauge with a pencil tip. This can be used for both horizontal and vertical markings. g Application of the sealant and primer. h, i Positioning of the bracket at the appropriate site. j, k Horizontal (j) and vertical (k) positioning of the bracket. l Using an intraoral mirror to verify the bracket position before light-curing.

Indirect Bonding

Indirect bonding requires initial positioning of brackets on a working model.1 , 2 Following bracket positioning on the model, a transfer tray is fabricated ( Table 6.7 ), which is then used to bond the brackets intraorally by transferring the brackets from the model to the patient’s teeth ( Table 6.8 ).

Advantages

Less chairside time is one of the main advantages claimed for this system, which is more convenient and comfortable for the patient. From the technical point of view, however, it is also significantly easier to bond the brackets on the teeth, as the positioning has already been carried out on the working model. This advantage may be more pronounced if the bonding is being carried out by an inexperienced operator.

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Jul 7, 2020 | Posted by in Orthodontics | Comments Off on Direct and Indirect Bonding Techniques
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