Accuracy evaluation of bracket repositioning by indirect bonding: hard acrylic CAD/CAM versus soft one-layer silicone trays, an in vitro study

Abstract

Objectives: Rapid development of digital technologies and 3D printing provide new tools for orthodontic indirect bonding. The purpose of this in-vitro study is to evaluate the clinical acceptability of hard CAD/CAM indirect bonding tray. Material & Methods: Ten soft silicone transfer trays and ten hard CAD/CAM trays were produced and 200 brackets were placed on them. The brackets were then transferred to twenty SLA-printed models by indirect bonding. These models were scanned and digitally compared to the reference model by three-dimensional superimpositions (GOM software). The linear and angular measurements were collected and analysed. Results: For the CAD/CAM trays, 100% of the mesiodistal, vertical and transverse measurements of incisors were within the clinical acceptable range of the American Board of Orthodontists (ABO) standards. More specifically, the clinically acceptable linear measurements were between 97 to 100% for silicone trays while they were between 89 to 100% for CAD/CAM trays. The clinically acceptable angular measurements varied between 87% and 100% for the silicone trays and between 79% and 100% for the CAD/CAM trays. Silicone trays were more precise than CAD/CAM trays. The difference was significant for all linear and angular measurements. Conclusions: While the CAD/CAM group shows clinically acceptable results according to the ABO, silicone remains to be more precise than CAD/CAM for transfer trays and is therefore still the reference. Clinical relevance: We demonstrate here that the orthodontic indirect bondings, whether they are realized using silicone transfer trays or CAD/CAM trays, are clinically acceptable in terms of the repositioning accuracy of brackets.

Accurate Bracket Placement with an Indirect Bonding Method Using Digitally Designed Transfer Models Printed in Different Orientations—An In Vitro Study

“…This supports our results. Torque showed the worst transfer accuracies of all angular dimensions, and the same result was found in previous studies [ 5 , 7 , 14 , 16 ]. Nui et al refer to an excess of bonding material or the transfer tray design to explain the outcome for torque [ 16 ].…”

“…We evaluated the accuracy of 1453 brackets and tubes placed with IDB, while other studies analyzed between 136 and 300 brackets [ 5 , 6 , 7 , 8 , 14 , 15 , 16 ]. Most other studies investigated IDB from the central incisor to the first molar.…”

“…The 3D printing of IDB trays was investigated in only a few in vitro studies. The testing of different materials and designs endorses their clinical usability [ 12 , 13 , 14 , 15 , 16 ].…”

CAD/CAM-gestützte Planung und Übertragungsmöglichkeiten von Brackets und Gaumenimplantaten

“…Für die konventionelle indirekte Klebetechnik gelten Silikon-Trays als Goldstandard hinsichtlich der Übertragungsgenauigkeit [28,29]. Pottier et al konnten in einer in-vitro-Untersuchung zeigen, dass die Übertagungsgenauigkeit von Brackets mit im DLP-Verfahren hergestellten flexiblen Schablonen (Shore Härte 40D) klinisch akzeptabel waren, allerdings im Vergleich weniger genau als die der Silikon-Trays [30]. Auch wenn weitere In-vitro-Untersuchungen zu Erfolg versprechenden Ergebnissen kommen [26,31], werden weitere In-vitro-und anschließende klinische Studien benötigt, um eine fundierte Empfehlung geben zu können.…”

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

“…More recently, computer-aided design/computer-aided manufacturing (CAD/CAM) transfer trays have been introduced [ 18 ], and studies of its accuracy have been conducted. It was suggested that the CAD/CAM transfer tray shows clinically acceptable results and is comparable to a silicone tray [ 19 ]. Xue et al also evaluated the accuracy of a newly designed bracket transfer device using CAD/CAM technology, and most of the measurements were within the clinically acceptable range, except for some brackets with torque deviation [ 20 ].…”