Title: Suitability of polymers as screw post materials in primary teeth: an in vitro study
Abstract: Aim Primary teeth undergo physiological root resorption during the transition to permanent dentition. The aim of this study was to assess the potential use of screw posts in core build-up for primary teeth while adequately retaining the crown restoration and allowing smooth physiological root resorption.
Methods To determine whether biodegradable polymers such as polyglycolic acid (PGA) and poly-L-lactic acid (PLLA) were appropriate as post materials, bending strength test and bending elastic modulus test were performed according to ISO standards. The prepared screw posts were immersed in 0.01 mol/L phosphate-buffered saline at 37 degrees Celsius, and changes due to hydrolysis were observed.
Results In the bending strength test and bending elastic modulus test, PGA and PLLA showed similar values to composite resins used for core build-up. Although both showed adequate hydrolysis, the hydrolysis rate of PGA was higher than that of PLLA. Significance: PGA and PLLA may be suitable as biodegradable screw posts for primary teeth because they have appropriate strength and hydrolysis ability.