Objective: To compare the orthodontic forces delivered by aligners with regard to the amount of activation, material type and time, and to determine the influence of beverages and nicotine on these forces.
Schlagwörter: aligners, beverages, orthodontic forces, thermoplastic materials
Materials and methods: An experimental study was conducted on 120 aligners made of polyethylene terephthalate glycol and polyurethane. The study environments included room temperature without immersion, artificial saliva (Gum Hydral gel, Sunstar, Etoy, Switzerland), Coca-Cola (Coca-Cola Company, Atlanta, GA, USA), coffee (Nescafé Original, Nestlé, Vaud, Switzerland), white wine (La Vague, Cave de Bir Drassen, Bir Drassen, Tunisia) and nicotine liquid (Nicoboost 20mg/ml PG50/VG50, Readiy, Le Cannet, France). The forces were measured using a thin film pressure sensor (Force-Sensitive Resistor [FSR] – Small SEN-09673, Interlink Electronics, Camarillo, CA, USA).
Results: The forces delivered by aligners increased significantly as the amount of activation increased. Polyethylene terephthalate glycol aligners showed significantly higher initial insertion forces than polyurethane aligners. After being immersed in artificial saliva for 24 hours, the aligners’ mean loss of efficiency was approximately 40%. Polyurethane aligners were more affected by various solutions (particularly hot coffee) compared with polyethylene terephthalate glycol aligners, which seemed to deliver more constant forces. The forces did not decrease in any of the studied cases.
Conclusion: Aligner performance is conditioned by the initial insertion force and the working range. Consumption of beverages and nicotine during aligner treatment does not appear to reduce aligner efficiency.