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 ).
The series of images in Fig. 6.10 illustrate the direct bonding technique in a step-by-step fashion.
OptraGate check retractors (Ivoclar, Vivadent, available in several sizes) provide good visibility of the working field.
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.
Direct bonding of self-ligating brackets allows visualization and removal of excessive bonding agent, preventing subsequent interference with the ligation mechanism.
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.
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 ).
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.