Simplicity and efficiency are the dreams of every clinician. Grasping advantages of both direct and indirect bonding techniques is the ideal solution for precise bracket positioning. The current article is a trial to demarcate the advantages of both techniques using augmented reality technology. Indirect bonding has proven superior precision and reduced chairside time in comparison with conventional direct bonding.2 Digital technology made an impact on the indirect bonding technique by further enhancing precision up to two decimal places when measuring distances from incisal edges for example.3
The proposed method can be compared to the direct bonding technique regularly used by most clinicians. They both require no to minimal lab work prior to bonding. The removal of excess composite flashes prior to photo-curing it is feasible as the brackets are uncovered in both techniques.
AR-assisted indirect bonding also uses the same precision of digital indirect bonding making it logically superior to manual indirect bonding. This might be due to the fact that with digital indirect bonding, the planning is up to two decimal places of millimeters accuracy, as opposed to eye-balling and scaled gages in manual indirect bonding. Errors may arise in both techniques of indirect bonding according to the expertise of the operator.
The novel method proposed in this article is based on a hybrid list of advantages from direct and digital indirect bonding techniques. The fact that an operator can virtually plan bracket positions and combine several images of the same patient for better visualization of the roots of teeth when positioning these brackets introduces a new level of bracket placement accuracy. The AR-assisted guide when compared to digital indirect bonding transfer trays, much cost efficient as it uses an everyday device that every clinician has in his/her pocket, a smartphone. The time required for 3D printing a transfer tray in the workflow of the digital indirect bonding techniques, is much longer than just transferring an application to a smartphone and using it in a VR headset, which will lead the operator to be up and running in lesser time.
When testing this AR-assisted bonding technique some learning curve difficulties were met. It takes some practice to calibrate one’s hand-eye coordination when dealing with the headset and viewing one’s hands through a screen rather than directly through the eyes. Perception of the dysmetria from one clinician to another may vary, similar to the first-time use of an endodontic microscope.
Another aspect that may have led to the minor discrepancies noted between the virtually planned bracket positions and the actual positions demonstrated in the final scan, is the size of the crosshairs in relation to the vertical and horizontal slot. In a wire sort of manner, some play may be present if the crosshairs do not fully inhabit both slots. The bracket position discrepancies were noticed specifically in the mesio-distal dimension rather than inciso-ginigval. In addition to the previous difficulties, the difficulty of intra-oral scanning metallic surfaces contributes to the inability to measure the discrepancies in an absolute manner, since the shapes picked-up by the scanner are not identical to the CAD versions of the brackets in the software. Titanium Oxide powder spray could have been used to acquire a better scan of the metallic brackets, but the shortcoming caused by adding a coating with a minor but significant thickness to the dental model was the reason not to pursue this solution, as it would also negatively influence the superimposition step.
The AR-assisted bonding technique, poses several advantages including less lab time, less cost and the ability to remove excess composite freely in comparison to indirect bonding utilizing transfer trays. The idea of decreased cost may arise from the unnecessary possession of special equipment such as a 3D printer and its resin material in addition.
Further clinical trials are to be performed to test the accuracy of the proposed method, but the concept behind this technique will most likely be perfected with time as the whole world is now shifting to a virtual environment. The discussed concept opens up a world of endless possibilities. This technique may not only be used for orthodontics, but it may as well prove to be beneficial in other fields and branches of dentistry.