Evaluation of custom-made 3D printed polylactic acid/polyethylene glycol scaffolds in soft tissue augmentation: an experimental study in a canine model

Histological and histomorphometric evaluation of the efficacy of custom-made three-dimensional (3D) printed poly-lactic acid (PLA)/ polyethylene glycol (PEG) scaffolds in horizontal soft tissue augmentation compared to connective tissue grafts (CTG) in Mongrel dogs. Horizontal ridge defects were created after tooth extraction in 12 dogs, then randomly allocated to one of the 3 study groups. 1 month after the first surgery, defects were augmented using custom-made 3D printed PLA/PEG scaffolds, or CTG or were left empty. 6 dogs were sacrificed after 1 month post-operatively, and 6 dogs after 3 months. Samples were collected for histologic evaluation. PLA/PEG and CTG groups successfully augmented soft tissue thickness. Histomorphometrically, fibroblast count (FC) was significantly higher in PLA/PEG group at both time points in comparison to CTG (p = 0.002 and 0.007) and control groups (p = 0.001 and 0.016). Percentage of collagen surface area (%CSA) was significantly higher in PLA/PEG group compared to other groups at 1 month (p = 0.021 and 0.001), however, it was higher in CTG group at 3 months (p = 0.024 and 0.003). 3D printed custom-made PLA/PEG scaffolds are an easy, effective, and safe method for soft tissue volume augmentation. The use of 3D printed scaffolds with properly designed internal structure guides the type of tissues regenerated and eliminates the need for CTG with its higher morbidity and complications.