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

Area of Science:

• Orthodontics
• Dental Materials Science
• Digital Dentistry

Background:

• Indirect bonding is a common orthodontic technique for bracket placement.
• Traditional polyvinyl siloxane (PVS) trays are widely used for indirect bonding.
• Advancements in 3D printing offer potential alternatives for fabricating transfer trays.

Purpose of the Study:

• To compare the transfer accuracy of two 3D-printed indirect bonding trays (Dreve FotoDent ITB and NextDent Ortho ITB) with conventional PVS trays.
• To evaluate linear and angular transfer errors in bracket positioning using different tray materials.
• To determine the frequency of clinically acceptable errors for each tray type.

Main Methods:

• Ten dental models were used to fabricate both 3D-printed and PVS transfer trays.
• Virtual bracket placement was performed on scanned dental models.
• Bracket positions were scanned post-indirect bonding, and linear/angular errors were measured.
• Statistical analysis included Kruskal-Wallis and chi-squared tests.

Main Results:

• All tested trays demonstrated comparable bracket placement accuracy.
• The NextDent tray showed a significantly higher frequency of rotational errors (>1°) compared to PVS trays (P = .01).
• PVS trays exhibited significant linear differences across tooth groups, while Dreve trays showed differences only in the buccolingual direction.

Conclusions:

• 3D-printed trays achieve accuracy comparable to PVS trays for indirect bonding.
• The NextDent tray may be less suitable than PVS trays due to a higher rate of clinically unacceptable errors.
• The Dreve 3D-printed tray demonstrated comparable performance to PVS trays, potentially reducing the influence of tooth anatomy on bracket positioning accuracy.