The irregularity of teeth positions, which is one of a variety of dental anomalies, can be cured by using orthodontic science. Nowadays, in addition to conventional methods such as brackets and metal wires, the use of traarent aligner is available. In this regard, the use of traarent coatings/aligners in orthodontic treatment, in addition to being invisible, can reduce the time of treatment by applying the force on the teeth. Due to the lack of identification of the maximum allowed force on the tooth during treatment, one of the goals of this study is to optimize the type and number of the traarent coatings/aligners when performing treatment on the patient. In this research, the process of producing the aligner is considered in each treatment stage based on the treatment plan. To discuss this, the treatment plan is evaluated based on the process and is decided by the simulation of the finite element method in order to accept or reject it. Actually, the input of this process is a digital 3D file of the patient's jaw. In the case of the lack of 3D jaw imaging device, in this research, the innovation of 3D image creation was utilized using a negative model and the creation of a gypsum mold to achieve a 3D image of the patient's jaw. Then, the modelling of the cloud files from the jaws of the patient is done in CATIA software in order to move on one or more defective teeth based on the treatment plan according to the dentist's opinion. After adjusting the necessary changes, the traarent cover is provided in the software. By using the simulation of the finite element method in ABAQUS software, the maximum force applied to the tooth is calculated after placing the traarent coating on the tooth. Then, by comparing the force calculated by the simulation and the maximum permissible force on the tooth, the necessary changes in the amount of displacement and the thickness of the traarent coating can be obtained. Due to the high volume of computations in the process of full collision of the traarent coating and jaw in the simulation of finite elements, in this study, the maximum force was calculated and estimated by considering the affected tooth and the two adjacent teeth, in comparison with the total teeth. Consider that, the changes will be based on the treatment plan and the dentist's opinion on the whole stages. Finally, after examining the maximum allowed force on the cured tooth and maximam allowable stress on the traarent aligner, a aligner of each treatment step is manufactured by the thermoforming machine. It is noteworthy to mention that, one of the innovations of this research is the creation of a gypsum mold from the 3D printed model for use in the thermoforming process. In summary, by using the design process discussed in this study, it is possible to optimize the number of stages of using traarent coatings according to the maximal force per tooth, which has been one of the goals of this research. By considering the results of this study, a treatment plan can be used to utilize the minimum thickness required for maximum tooth displacement at each stage of the treatment. Besides that, the number of traarent coatings will be reduced during treatment. In addition, the maximum force applied to each tooth in the simulations is also considered to prevent damage to the tooth. Keywords: Tooth, Aligner, Orthodontics, Traarent Orthodontics, Limited Components