Bracket transfer accuracy with two different three-dimensional printed transfer trays vs silicone transfer trays

ABSTRACT Objectives To compare the transfer accuracy of two different three-dimensional printed trays (Dreve FotoDent ITB [Dreve Dentamid, Unna, Germany] and NextDent Ortho ITB [NextDent, Soesterberg, the Netherlands]) to polyvinyl siloxane (PVS) trays for indirect bonding. Materials and Methods A total of 10 dental models were constructed for each investigated material. Virtual bracket placement was performed on a scanned dental model using OnyxCeph (OnyxCeph 3D Lab, Chemnitz, Germany). Three-dimensional printed transfer trays using a digital light processing system three-dimensional printer and silicone transfer trays were produced. Bracket positions were scanned after the indirect bonding procedure. Linear and angular transfer errors were measured. Significant differences between mean transfer errors and frequency of clinically acceptable errors (<0.25 mm/1°) were analyzed using the Kruskal–Wallis and χ2 tests, respectively. Results All trays showed comparable accuracy of bracket placement. NextDent exhibited a significantly higher frequency of rotational error within the limit of 1° (P = .01) compared with the PVS tray. Although PVS showed significant differences between the tooth groups in all linear dimensions, Dreve exhibited a significant difference in the buccolingual direction only. All groups showed a similar distribution of directional bias. Conclusions Three-dimensional printed trays achieved comparable results with the PVS trays in terms of bracket positioning accuracy. NextDent appears to be inferior compared with PVS regarding the frequency of clinically acceptable errors, whereas Dreve was found to be equal. The influence of tooth groups on the accuracy of bracket positioning may be reduced by using an appropriate three-dimensional printed transfer tray (Dreve).

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

Despite being associated with more accuracy, the indirect bonding procedure is not yet the gold standard, probably because of sensitivity of the numerous variables that must be controlled. The aim of this article was to present a modified, standardized, and low-cost indirect bonding technique that allows this procedure to be performed successfully. The technique covers an initial clinical stage, to obtain the models; a laboratory stage, which involves placement of brackets on the models following the facial axis of the clinical crown and the labial projection of the marginal ridges of the posterior teeth and construction of transfer tray using hot glue; and a second clinical stage, to properly transfer the brackets to patient’s teeth. Hot glue used to build the tray molds the teeth and perfectly adapts to the teeth, having enough stiffness to maintain their anatomy and the position of the brackets, but also presenting adequate flexibility to allow removal of the tray avoiding excessive stress over the brackets. In conclusion, the new simplified indirect bonding technique presented here provides a precise placement of brackets on the models, a cheaper way to transfer them to patient, and an easy removal of transfer tray, being a very simple and cost-effective method.

Fluxo digital na montagem simplificada de bráquetes linguais

Introduction: In lingual orthodontics technique the brackets are positioned on the teeth lingual surface, and for this reason it is known as a difficult technique due to the complexity of brackets positioning. During the evolution of this technique many forms of lingual appliance assembly were developed. The most used technique recommended to make an orthodontic set-up model and later to transfer the appliance to the patient’s mouth using trays or jigs in order to perform the bonding itself. Subsequently, another and more simplified lingual appliance form emerged, in which the bonding would be performed directly, that is, on the lingual surface of the enamel, but it required greater skill from the professional. Also, it could be done on the cast model of malocclusion, without making the set-up model. Objectives: To facilitate the technique using technological resources with as a scanner and a software replacing some analogical steps in the assembly of the lingual device. Material and Method: Intraoral digitizing is performed by a scanner where the models are obtained in STL files, that inserted in the software together with the STL files of the lingual brackets will be positioned on the virtual surface of the digital models. A virtual transfer tray will be made of resin in a 3D printer where the metal brackets will be inserted for the actual bonding. Conclusion: The assembly of the simplified lingual device can be performed with excellence by digital means in almost all steps.

Digital Workflow for Indirect Bonding with 2D Lingual Brackets: A Case Report and Procedure Description

Objective. During orthodontic therapy, accuracy in bonding procedures makes it easier to correct tooth alignment by decreasing the need for midcourse corrections by changing bracket positions. Indirect bonding allows the transfer of the appliance components from model casts to patient’s teeth potentially meaning shorter appointments for bracket bonding and rebonding and best comfort during chairside practice. At the same time, there has been a steady increase in requests for invisible lingual orthodontic treatment.Clinical Considerations. Accordingly, the aim of the present report is to illustrate the workflow to realize a complete digital indirect bonding for lingual brackets (2D, Forestadent). The procedure starts with intraoral digital scans, digital 3D model, and virtual bracket positioning, ending with the realization of a CAD-CAM prototyped transfer tray. A 3D intraoral scanner (True Definition, 3M) is used to create digital scans and digital models. A virtual bracket positioning is performed using software (NemoCast, Dentaurum), and a prototyped transfer tray is created by a CAD-CAM device. 2D lingual brackets were positioned inside the tray, so the appliance was bonded to the dental surface using light curing adhesive resin.Conclusions. During orthodontic treatment, CAD/CAM technology could help clinicians. Computer-constructed transfer trays can reduce clinician error and improve the everyday workflow in the office.

Indirect orthodontic bonding - a modified technique for improved efficiency and precision

INTRODUCTION: The indirect bonding technique optimizes fixed appliance installation at the orthodontic office, ensuring precise bracket positioning, among other advantages. In this laboratory clinical phase, material and methods employed in creating the transfer tray are decisive to accuracy. OBJECTIVE: This article describes a simple, efficient and reproducible indirect bonding technique that allows the procedure to be carried out successfully. Variables influencing the orthodontic bonding are analyzed and discussed in order to aid professionals wishing to adopt the indirect bonding technique routinely in their clinical practice.