Study to Develop Resorbable Membrane for Guided Periodontal Tissue Regeneration

Objectives: This study aimed to develop customized resorbable copolymer membranes for use in guided tissue regeneration (GTR) and to evaluate their mechanical properties.

Methods: A copolymer was synthesized from 70 mol% L-lactide (LL) and 30 mol% epsilon-caprolactone (CL) by ring opening polymerization. Poly(LL-co-CL) membranes were prepared by film casting and sterilized by gamma radiation. In an in vitro degradation study, the membranes were immersed in PBS for 16 weeks. At each week, membranes were dried and subjected to mass weight and molecular weight determination, thermal property determination, scanning electron microscopic (SEM) examination and tensile strength testing. Additionally, pH of the media was measured.

Results: The mass weight of membranes and pH of media were stable in the first 4 weeks and gradually decreased over time. The molecular weight highly decreased after week 1 and gradually decreased over time. Regarding the thermal properties, melting temperature (Tm) decreased, while enthalpy of melting (ÄHm) continuously increased in the first run. In the second run, glass transition temperature (Tg), crystallization temperature (Tc) and Tm decreased, while enthalpy of crystallization (ÄHc) and ÄHm increased. By SEM, surface roughness of membranes increased over time. These suggested that membranes could degrade in vitro. Regarding the tensile strength testing, the membranes had a tensile strength of 9.54 ± 0.35 MPa at the beginning and dropped to 3.91 ± 0.66 MPa at week 4.

Conclusions: Poly(LL-co-CL) membranes have a potential to be used as the GTR membranes due to their degradability.