The physical property evaluation of degradation thermoplastic polylactic acid net-reinforced dental filling material

Filling materials are used in root end surgery to seal the cavities of teeth and protecting teeth from saliva and bacterial leakage. This study fabricates nonwoven nets using low-melting point polylactic acid (PLA) fibers. Intermediate restorative material (IRM®, a temporary filling material) is made of zinc oxide powder and eugenol solvent with a 3:1 ratio. IRM is then added with PLA fibers or nets to form the fiber-reinforced composite filling material (FFM) or net-reinforced composite filling material (NFM), respectively. FFM and NFM are tested in terms of setting time, compressive strength, solubility, and microleakage to compare the difference between the addition of fibers or nets. The results show that FFM with 2% PLA fibers demonstrates an optimal reinforcing effectiveness and does not cause leaking beyond 40 days after being tested. In addition, it also has better compressive strength than IRM and thus provides greater reinforcement.