Preparation of Poly Lactic-Co-Glycolic Acid-Based Implant Biomaterials and Its Adoption in Restoration of Periodontal Missing Teeth

As a commonly used macrolide antibiotic, azithromycin (AZM) has achieved favorable results in the treatment of periodontitis. However, due to the complex environment of the oral cavity, the time of action of topical medication is limited. In this study, AZM-poly lactic-co-glycolic acid (PLGA) microspheres were prepared by the emulsion-solvent evaporation method, whose morphology was observed by scanning electron microscopy. The AZM-PLGA microspheres of different specifications were obtained by using a paddle agitator and a homogenizing agitator, respectively. For the above two different specifications of AZM-PLGA microspheres, the mass ratios of AZM and PLGA were adjusted to 10:100, 15:100, 20:100, and 30:100, respectively. After the mechanical analysis of the microspheres, the slurry-type AZM-PLGA microspheres were taken as the positive control, and the critical defect model of alveolar bone was implanted in New Zealand white rabbits. Then, CT imaging of alveolar bone tissue was obtained at different time points after surgery. Plasma microspheres (20:100) were selected as the implant materials for the restoration of missing teeth in patients with periodontitis. After the test, the results showed that the AZM-PLGA microspheres obtained by the paddle agitator had relatively smaller particle size and smoother surface. The initial release rate of slurry microspheres of different quality was relatively fast, the follow-up rate was relatively stable, and the dosage ratio should not be more than 20%. Slurry microspheres had stronger mechanical properties compared with homogenized microspheres. The osteogenesis observation residues of slurry microspheres with different mass ratios were 15%, 23%, 37%, and 26% at 2–16 weeks, respectively, showing a relatively stable degradation mode. After the five patients with periodontitis participated in the restoration with the use of plasma microspheres (20:100) implants, the periodontal condition was greatly improved. During the observation period, all implants were not loosened and there was no discomfort during percussion.