Effect of adipose-derived stem cells and their exo as adjunctive therapy to nonsurgical periodontal treatment: A histologic and histomorphometric study in rats

Scaling and root planing (SRP) is of limited value in many cases, so adjunctive treatment was applied to augment its outcome. Adipose-derived stem/stromal cells (ADSCs) were investigated in periodontal regeneration with promising results. However, they have safety concerns. The exosomes (Exo.), which are extracellular vesicles mediating the action of stem/stromal cells, represent a new approach to overcome these concerns. Ligature-induced periodontitis was induced in 50 rats for 14 days, and they were divided into control (5 healthy rats for histologic comparison), SRP group, ADSCs group, and Exo. group, with evaluation intervals at 2 days, and 2 and 4 weeks, including 5 rats in each interval for each group. The specimens were evaluated for histologic description (H&E), histochemical study (Masson trichrome), and histomorphometric study, to evaluate the area % of newly formed tissues. The Exo. group revealed the best results in all intervals with significantly higher area % of newly formed tissues, followed by ADSCs and, finally, SRP. Both Exo. and ADSCs showed organized newly formed tissues with the Exo. group obtaining comparable histologic results to the normal, healthy tissues by 4 weeks. Adipose-derived stem/stromal cells and their Exo. represent a promising adjunctive treatment to SRP.