The Application Of The Light-cured Model Material Transfer Tray Indirect Bonding In Labial Orthotherapy

Objectives:In this study,we developed the light-cured model material transfer tray,by comparing the strength and hardness,the volume of the transfer tray,the placement time,the placement failure rate,and the transfer accuracy with the double layer siloxane rubber transfer tray indirect bonding.Clarify the performance characteristics of the light-cured model material transfer tray,and provide a theoretical basis for the clinical application and promotion of the light-cured model material transfer tray.Methods:The study subjects were selected from orthodontic department of the Affiliated Stomatological Hospital of Kunming Medical University from 2018 to 2019,all patients were treated with straight wire technique.The patients were randomly divided into three groups:direct bonding group,indirect bonding group A and indirect bonding group B.Direct bonding group used direct bonding,and indirect bonding group A used the light-cured model material transfer tray indirect bonding,and indirect bonding group B used the double layer siloxane rubber transfer tray indirect bonding.Part Ⅰ:The double layer transfer tray was improved,the inner layer was cove with red wax as a cushion so as to determine the thickness and range of siloxane rubber light body,the outer layer is made of the HUGE light-cured model material;Using a universal testing machine three-point bending test to determine the flexural strength and elastic modulus of the silicone rubber heavy body and the HUGE light-cured model material;Ten patients were randomly selected to make the light-cured model material transfer tray and double layer siloxane rubber transfer tray and measure the volume;The two samples T-test analysis was carried out with SPSS 19.0 software on measurements the flexural strength and elastic modulus of the two materials and the volume between the two transfer tray.Part Ⅱ:Record the placement failure situation for 6 months and operation time of direct bonding group,indirect bonding group A and indirect bonding group B,the Chi-square test analysis was carried out with SPSS 19.0 software on measurements the placement failure rate and distribution among the three groups,the two samples T-test,one-way variance and Bonferroni test analysis was carried out with SPSS 19.0 software on measurements the operation time among the three groups;Five patients were randomly selected who are using the light-cured model material transfer tray indirect bonding,the iTero intraoral scanner and Dolphin imaging software was used to measure the position of the bracket before and after transfer,the paired T-test analysis was carried out with SPSS 19.0 software on measurements the brackets position before and after transfer.Results:1.The flexural strength and elastic modulus of the HUGE light-cured model material is much higher than the silicone rubber heavy body,which guarantees higher hardness and strength of the transfer tray;2.The light-cured model material transfer tray have smaller volume;3.The light-cured model material transfer tray indirect bonding can effectively reduce the placement failure rate of buccal tube;4.The light-cured model material transfer tray indirect bonding has the characteristic of saving chair-side operation time;5.The light-cured model material transfer tray indirect bonding has higher transfer accuracy.Conclusions:1.The light-cured model material transfer tray was successfully designed and made by using Huge light-cured model material;2.The Huge light-cured model material has higher hardness and strength,which provides better stability for the transfer tray.The covered with wax as a cushion method,the light-cured model material transfer tray has smaller volume;3.The light-cured model material transfer tray with higher hardness and strength and smaller volume has the characteristics of effectively reducing the placement failure rate of buccal tube,saving the chair-side operation time and the leading transfer accuracy;4.The performance of the light-cured model material transfer tray is better than the traditional double layer siloxane rubber transfer tray,the light-cured model material transfer tray can be used in orthodontics clinic.