Browsing by Subject "Indirect Bonding"

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    Indirect bonding of orthodontic Brackets: an evaluation of transfer accuracy and reliability
    (2014-06) Lee, Michael Steven
    Background: Indirect bonding of orthodontic brackets has been viewed as a method of achieving greater accuracy and effectiveness in orthodontic treatment. Although the concept of indirect bonding has been widely studied, the accuracy of the transfer between the indirect stone model-set of the brackets to the patient's dentition has not been investigated in a clinical setting. The goal of the present study is to elicit the frequency, directional bias, and magnitude of bracket positioning errors due to this transfer.Methods: A total of 163 brackets were initially placed on indirect stone model set-ups and scanned using a cone-beam computed tomography system to capture 3-D bracket positioning data. These brackets were then transferred to the patient's dentition and later scanned using CBCT to capture the final 3-D bracket positioning on the teeth. Virtual models of the teeth and attached brackets were constructed from the scanned data. Initial and final pairs of models were digitally superimposed. Differences in bracket positioning were measured using customized software. One-tailed t-tests were used to compare measurement data with the pre-determined acceptable ranges of +/- 0.5 mm linearly and 2.0 degrees angularly for differences in each of 6 dimensions studied. Results: The indirect transfer of brackets resulted in accurate positioning (&alpha = 0.05, P < 0.0001). Bracket positioning along mesial-distal, buccal-lingual, and vertical axis most frequently satisfied the accuracy requirements. The indirect bonding transfer of brackets had a modest bias towards the buccal and gingival. The bracket failure (detachment) rate in this study was 9.8%.Conclusions: The indirect bonding transfer is statistically accurate and reliable.
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    Transfer Accuracy of 3D-Printed Trays for Indirect Bonding of Orthodontic Brackets: A Clinical Study
    (2021-06) Bachour, Petra
    Aim: To evaluate the transfer accuracy of 3D-printed indirect bonding trays constructed using a fully digital workflow in a clinical setting.Methods: Twenty-three consecutive patients had their incisors, canines, and premolars bonded using a fully digital indirect bonding method and 3D-printed transfer trays. Intraoral scans were taken to capture the final bracket positioning on the teeth following bonding. Digital models of the post-bonding scans were superimposed on those of the 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 limits of 0.5 mm in the mesio-distal, bucco-lingual, and occluso-gingival 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 mesio-distal, bucco-lingual, and occluso-gingival measurements, respectively. For the linear dimensions, frequencies of bracket positioning error within the 0.5-mm limit ranged from 96.4–100%. Mean differences were significantly within the acceptable range for these dimensions. Mean differences were 2.55°, 2.01°, and 2.47° for torque, tip, and rotation, respectively. For the angular measurements, frequencies within the 2°-limit ranged from 46.0–57.0%. The mean differences for the angular dimensions were outside the acceptable limit; however, this may have been due to limitations of the scan data. Conclusions: Indirect bonding using 3D-printed trays transfers the planned bracket position from the digital setup to the patient’s dentition with a high positional accuracy in the mesio-distal, bucco-lingual, and occluso-gingival dimensions. Questions remain regarding the transfer accuracy in the angular dimensions.