Histological Evaluation of Restylane Lyft Used as a Scaffold for Dental Pulp Regeneration in Non-Infected Immature Teeth in Dogs.

Commercially available hyaluronic acid dermal fillers used as a scaffold in regenerative endodontic procedures (REPs) have demonstrated attractive potentials. This study aimed to histologically evaluate the outcome of REPs using Restylane Lyft (HA) as a scaffold. REPs were performed on pulpless, immature roots in dogs (n = 69). The roots were divided into four groups: blood clot (BC), Restylane Lyft (BC + HA), negative control, and positive control. At 13 weeks postoperatively, hard tissue formation, vascularization, the presence of vascularized soft connective tissue and collagen fibers, the degree of inflammation within pulp spaces and/or periapical tissues, and apical closure were evaluated histologically. The vascularization and formation of loosely arranged collagen fibers within the regenerated soft connective tissues were observed significantly more in the BC+HA group (85% and 40%, respectively; p < 0.05) compared to the BC group (54.6% and 9.1%, respectively; p < 0.05). The degree of inflammation was significantly higher in the HA group than in the BC group; moderate to severe inflammatory cell infiltration was seen in 45% and 13.6% of the cases, respectively. The results of the present study suggest that Restylane Lyft combined with a blood clot used as a scaffold may improve the outcomes of REPs in non-infected, pulpless, immature teeth in dogs.

Evaluation of a hyaluronic acid hydrogel (Restylane Lyft) as a scaffold for dental pulp regeneration in a regenerative endodontic organotype model.

Scaffolds are crucial elements for dental pulp regeneration. Most of the currently used scaffolds in regenerative endodontic procedures (REPs) are unsuitable for chairside clinical use. This study aimed to evaluate the effect of an injectable synthetic scaffold (Restylane Lyft) on human bone marrow mesenchymal stem cell (hBMSC) viability, proliferation, and osteo/dentinogenic differentiation in a regenerative endodontic organotype model (REM). hBMSC were loaded in an REM either alone (hBMSC group) or mixed with the Restylane Lyft scaffold (Restylane/hBMSC group) and cultured in basal culture medium (n = 9/group). hMSC on culture plates served as controls. Cell viability and proliferation were measured using AlamarBlue assay. The loaded REM was cultured in an osteogenic differentiation medium to measure alkaline phosphatase activity (ALP) and examine the expression of the osteo/dentinogenic markers using real-time reverse transcriptase polymerase chain reaction. Cell viability in all groups increased significantly over 5 days. The Restylane/hBMSC group showed significantly higher ALP activity and dentin sialophosphoprotein, osteocalcin, and bone sialoprotein genes expression than the hBMSC and the control groups. Restylane Lyft, a hyaluronic acid (HA) injectable, FDA-approved hydrogel, maintained cell viability and proliferation and promoted osteo/dentinogenic differentiation of hBMSC when cultured in an REM. Henceforth, it could be a promising chairside scaffold material for REPs.