Indirect Bonding Revisited

Abstract

In recent years, the popularity of indirect bonding increased due to advantages such as reduction of chair time and enhancement of patient comfort. Although the indirect bonding technique has improved over the years, the literature has shown different techniques of bracket placement; furthermore, new materials were specially developed for this technique. The aim of this article is to provide a review of the literature, advantages, disadvantages, and laboratory and clinical stages of the indirect bonding technique. Keywords: Indirect bonding, bonding systems, orthodontics indirect technique INTRODUCTIONIndirect bonding was developed by Silverman and Cohen (1) in 1972 to reduce clinical time and to enhance patient comfort. In this method, they used cement for attaching brackets to the stone model, a sealant as a clinical adhesive, and thermoplastic trays for the transfer of the brackets. In 1979, Thomas (2) invented "custom composite base technique, " which is still the most widely accepted technique currently used for indirect bonding. In this technique, Thomas used a chemically-cured resin for attaching the brackets in a laboratory and a universal and a catalyst resin as the clinical adhesive. The major complication of the Thomas technique is that the polymerization of the chemical resin starts in the patient's mouth, which is problematic in terms of time. If the transfer tray was removed before the completion of polymerization, bracket failure can be seen, and if the tray was left in the mouth for too long, this can disrupt the patient comfort. To solve this problem, the Thomas technique was modified; the universal and catalyst resins were mixed outside the mouth and directly applied to the teeth and custom base (3). With the modified Thomas technique, indirect bonding achieved similar bond strength values compared with direct bonding.In the previous literature, chemically-cured resins were usually used as clinical adhesives for indirect bonding. Apart from these resins, glass ionomer cements, acrylic epoxy adhesives, and cyanoacrylates were also used (4-6).Read and O'Brien (7) used light-cured resins for indirect bonding in 1990, and with the advantages of these resins, the indirect bonding technique was further enhanced.In 2002, Miles (8) used a flowable composite in indirect bonding. The most important advantage of this resin was to fill the voids of the custom base with its favorable viscosity.With the advancement of technology, computers entered the practice of orthodontics, thereby enhancing the indirect bonding technique. Several companies offer three-dimensional computer-aided design and computer-aided manufacturing (3D CAD-CAM)-generated methods for the fabrication of indirect bonding trays. In one of these, Suresmile (Orametrix Inc.; Dallas, USA) system (9), teeth are scanned using an intraoral scanner, and computer generated 3D images are produced. These 3D images are used for digital set-up, and the brackets are placed in appropriate regions of the teeth. The customized transfer trays for in...

The Most Important Risk Factors Affecting the Physical Health of Orthodontists: A Pilot Study

“…Finally, it is believed that new orthodontic technologies can help to secure a practitioner's health by minimizing chairside time. For example, shortened chairtime appears to be one of the main reasons for the relatively high frequency of self-ligating vs. conventional ligating brackets or indirect bonding application by clinicians currently [23,24].…”

The Indirect Bonding Technique in Orthodontics—A Narrative Literature Review

“…As a result, the bonding resin gained hydrophilic groups and its ability to penetrate the etched enamel was improved. SBS was significantly higher, because the adhesion booster could compensate for imperfections responsible for increasing the risk of failure, such as aprismatic or hypomineralized enamel structure [19].…”

“…It was estimated that 2%-6% of brackets bonded indirectly revealed an undesirable loss, probably due to insufficient connection with dental hard tissues [19]. To decrease the risk of unwanted debonding of custom-based brackets, researchers suggested improving the properties of bonding resin by adding an "adhesion booster".…”

Indirect orthodontic bonding with drop-shaped hot glue tray: a simple and cost-effective technique

“…Additionally, the various advantages of indirect technique have remained, especially the better visualization of teeth in the model than in patient's mouth, offering greater precision in bracket positioning (Guenthner and Larson 2007;Agarwal and Kulshrestha 2017;Singh et al 2019) and improving ability to bond posterior teeth (Aggarwal and Aggarwal 2018;Kalra et al 2018). Literature also mentions the reduced chair time (Kalange 2004;Pamukçu and Özsoy 2016;Li et al 2019;Singh et al 2019) and the possibility of simultaneous bonding of several accessories (Kalange 2004;Aggarwal and Aggarwal 2018), so making the procedure attractive to both operator and patient. Some variations have been described to carry out this technique over the years with several advances, standing out especially on the adhesive used to attach brackets to casts (Sondhi 2007) and on the transfer tray material used, eg, thermal glue (White 1999), rapid prototyped (Ciuffolo et al 2006), silicone (Guenthner and Larson 2007), vacuum-formed (Sondhi 2007), vinil polysiloxane (Grünheid et al 2016), or associated methods (Ciuffolo et al 2012).…”