Transfer accuracy of 3D-printed trays for indirect bonding of orthodontic brackets:

ABSTRACT Objectives To evaluate the transfer accuracy of 3D-printed indirect bonding trays constructed using a fully digital workflow in vivo. Materials and Methods Twenty-three consecutive patients had their incisors, canines, and premolars bonded using fully digitally designed and 3D-printed transfer trays. Intraoral scans were taken to capture final bracket positioning on teeth after bonding. Digital models of postbonding scans were superimposed on those of corresponding virtual bracket setups, and bracket positioning differences were quantified. A total of 363 brackets were evaluated. One-tailed t-tests were used to determine whether bracket positioning differences were within the limit of 0.5 mm in mesiodistal, buccolingual, and occlusogingival dimensions, and within 2° for torque, tip, and rotation. Results Mean bracket positioning differences were 0.10 mm, 0.10 mm, and 0.18 mm for mesiodistal, buccolingual, and occlusogingival measurements, respectively, with frequencies of bracket positioning within the 0.5-mm limit ranging from 96.4% to 100%. Mean differences were significantly within the acceptable limit for all linear dimensions. Mean differences were 2.55°, 2.01°, and 2.47° for torque, tip, and rotation, respectively, with frequencies within the 2°-limit ranging from 46.0% to 57.0%. Mean differences for all angular dimensions were outside the acceptable limit; however, this may have been due to limitations of scan data. Conclusions Indirect bonding using 3D-printed trays transfers planned bracket position from the digital setup to the patient's dentition with a high positional accuracy in mesiodistal, buccolingual, and occlusogingival dimensions. Questions remain regarding the transfer accuracy for torque, tip, and rotation.

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).

Three-Dimensional Digital Superimposition of Orthodontic Bracket Position by Using a Computer-Aided Transfer Jig System: An Accuracy Analysis

Accurate bracket placement is essential for successful orthodontic treatment. An indirect bracket bonding system (IDBS) has been developed to ensure proper bracket positioning with three-dimensional computer-aided transfer jigs. The purpose of this study was to investigate the accuracy of bracket positioning by a one-body transfer jig according to the tooth type and presence/absence of a resin base. In total, 506 teeth from 20 orthodontic patients were included in this study. After initial dental models were scanned, virtual setup and bracket positioning procedures were performed with 3D software. Transfer jigs and RP models were fabricated with a 3D printer, and brackets were bonded to the RP model with or without resin base fabrication. The best-fit method of 3D digital superimposition was used to evaluate the lineal and angular accuracy of the actual bracket position compared to a virtual bracket position. Although all the measurements showed significant differences in position, they were clinically acceptable. Regarding the tooth types, premolars and molars showed higher accuracy than anterior teeth. The presence or absence of a resin base did not consistently affect the accuracy. In conclusion, the proper application of IDBS should be performed considering the errors, and resin base fabrication might not be essential in ensuring high-accuracy IDBS.

Multipurpose Bracket Positioning Tool: A Modified Probe for Accurate Bracket Placement

There is no single bracket gauge that can be used universally for all teeth to orient brackets in the vertical and axial planes simultaneously. To overcome the increased armamentarium and steps involved in accurately positioning brackets, we have modified a UNC-15 probe to fabricate a multipurpose bracket positioning tool (MBP tool). Thus, one single instrument can be used not only to position brackets (both anterior and posterior) in all planes but also for the quick verification of positioned brackets just before curing.

PERSONIFIED APPROACH TO SELECTING A METHOD FOR BRACKET POSITIONING WITH 3D TECHNOLOGY

The concept of creating the so-called esthetic smile is still subject to debate. While there is no optimal way to achieve the smile esthetics, this fact drove the idea of improving the available algorithms employed for the treatment of dentofacial anomalies. Smile reconstruction in orthodontic treatment is a complex process, which is subject to certain rules and laws, and takes an interdisciplinary approach from dental specialists. When dealing with dental anomalies, one of the most important practical components is the correct method of the braсket positioning. Based on the analysis of the options offered currently by digital technologies, and the negative outcomes of orthodontic treatment, the following aim was set for the current study – to improve the algorithms employed to select individual methods of bracket personalized placement as per each clinical situation in particular. The methods used through the study included: clinical, digital, statistical, and analytical one. Following the criteria of the esthetic smile, the location, the shape and the structure of the teeth of a particular patient, an individual method for bracket positioning was developed, the final outcomes of that being a smile with individual parameters. This method allows achieving a maximum esthetic result. The proposed technique is the method of choice in each specific clinical situation and can be used depending on the indications.

Digital orthodontic indirect bonding systems: A new wave

Digital technologies are progressing with leaps and bounds and the field of orthodontics is not untouched by it, with innovations like intraoral scanners and 3D printers being easy to own and maintain and increased availability of biocompatible 3D printing materials orthodontist are curious to use this technology to improve orthodontic bracket positioning which would require minimal to no repositioning during the course of treatment. The authors here have tried to outline 2 different methods using CBCT and VTO as guide to decide the bracket positioning digitally and using 3D printed Indirect Bonding trays for orthodontic bonding.