Accuracy of 3D Printed Indirect Bonding Trays - an in Vivo Study

Overview

Objective In addition to examining the transmission accuracy of rigid and non-rigid IDB's the aim of the study is to determine the 'lost rate' during the placement. The 'lost rate' is the percentage frequency of brackets that have no adhesion to the model after the bonding has taken place. Hypothesis The main hypothesis does not describe a significant deviation of the digitally planned to the actually placed bracket position in directions and angles described. The secondary hypothesis is the assumption of no significant difference between the accuracy and lost rate of the two materials. Method 24 orthodontic patients treated with multibracket appliance will be included for the planned study. In order to increase the reproducibility of the acquired data four different model situations are included. Objective The aim of the study is a scientific examination of the accuracy of digital printed bonding trays using two materials to support the decision process of the potential user and their dental laboratories. The study allows an insight into the technical manufacturing process and its workflow.

Orthodontic clinicians distinguish between direct and indirect brackets placement. Using the direct procedure, brackets are placed on the patients tooth without a transfer appliance. While the indirect method takes advantage of placing the brackets on a dental model under laboratory surrounding. The conventional method of indirect bracket positioning uses plaster models from the treated dental arches. Following the positioned brackets are transferred from the model to the patient mouth using a so called indirect bonding trays (IDB). IDB's represent a transfer aid for the bracket placement. Advantages of this procedure can be an improvement of the tooth axis (facial axis) assessment especially since the model is freely movable in space further an optimized visibility with laboratory lighting. The placement on the digital model offers a variety of options with regards to measurement, magnification, contrast adjustment and exact referencing on the neighboring tooth. Digital Workflow: Under the broad term of rapid prototyping developments of applications allow a fully digital workflow while planning and manufacturing IDB's. The construction of bonding trays is based on a digital 3D model and is further manufactured using stereolithographic 3D printers. Similar to conventional IDB's there is the question of the optimal material with regards to transfer accuracy, dimensional stability and clinical applicability with 3D printed IDB's. Besides the question of transfer accuracy, the planned study will document the percentual number of brackets which failed to bond with the corresponding tooth (Lost Rate) using two different materials. Objective: The aim of the study is a scientific examination of the accuracy of digital printed bonding trays using two materials to support the decision process of the potential user and their dental laboratories. The study allows an insight into the technical manufacturing process and its workflow.