The effect of time on mechanical properties of biocompatible photopolymer resins used for fabrication of clear dental aligners

Clear dental aligners are used for treating orthodontic anomalies (misaligned teeth, inappropriate contact between upper and lower teeth etc.), minor irregularities and bruxism. Using additive manufacturing technologies clear dental aligners are made of biocompatible photopolymer, using a vat photopolymerization technology. One of problems in application is the change of aligner material properties after production, including strength and elongation at failure. This can cause different sequence of tooth displacement which will not correspond to the planned therapy. In this paper three types of material testing are conducted i.e., tensile, compressive and threepoint bending testing on specimens of 1 (24 h), 3 (72 h), 5 (120 h) and 7 (168 h) days old. Mechanical properties, such as tensile, compressive and flexural strength and strain at failure are monitored in order to show the effect of time on biocompatible photopolymer resin.

Automated summary

This study investigates the changes in material properties of clear dental aligners over time, with tests including tensile, compressive and three-point bending testing. The mechanical properties, such as strength and strain at failure, of biocompatible photopolymer resin are monitored to demonstrate the effect of time.