Long-term morphological evaluation of porous poly-DL-lactic acid for soft tissue augmentation

Abstract

Soft tissues are important for aesthetic considerations in implant therapy. The purpose of this study was to investigate soft tissue augmentation by using porous poly-DL-lactic acid (PDLLA) shaped as a tablet, with a diameter of 5.0 mm and a height of 2.0 mm. Porous PDLLA was implanted between the periosteal and epithelial tissues in 25 rats that were sacrificed at 1, 2, 4, 12, and 24 weeks. The average height of the PDLLA scaffolds at approximately 24 weeks was 1.85 ± 0.08 mm, and the molecular weight decreased with time. Sinusoidal capillaries at 1 week, connective tissues at 4 weeks, and necrotic tissues at 24 weeks were observed more than other periods. At 24 weeks, the connective tissue surviving in the pores was confirmed to contain blood vessels; therefore, blood vessels are considered to be critical for the survival of soft tissue in scaffold pores. In this study, PDLLA was found to be useful for soft tissue augmentation in the long term. Although the molecular weight of PDLLA decreased with time, the height of the PDLLA scaffolds was preserved. The connective tissue surviving in the pores of the scaffolds at 24 weeks were associated with blood vessels. Further studies are necessary to investigate the optimal scaffold shape and surface characteristics to improve the penetration of blood vessels.

Lateral Bone Window Closing Technique with Poly‐L‐Lactic Acid (PLLA) Membrane in the Augmentation of the Maxillary Sinus without Grafting Material: Evaluation of Bone Healing in a Rabbit Model

“…The use of PLLA as a biomedical material has been widely studied in the areas of tissue engineering, bone healing materials, and drug delivery because of its nonantigenicity, reasonably good mechanical properties, biodegradability, and biocompatibility. [24][25][26][27][28] Histomorphometric analysis has been highly regarded as the gold standard for its versatility among various measuring methods. Crespi and colleagues reported a sinus lift procedure using autologous bone graft material by a histomorphometric study.…”