Effect of autologous conditioned serum (ACS) on histological characteristics and expression of soft tissue IL-1β gene after horizontal ridge augmentation surgery.

Background: Horizontal ridge augmentation surgeries are common procedures in periodontics. Histological changes in soft tissues affect the success of surgery in many ways. Autologous conditioned serum (ACS) increases interleukin-1 receptor antagonist (IL-1Ra) and causes inflammation modulation. Therefore, the present study aimed to investigate the effect of ACS on histological changes and gene expression of soft tissues after horizontal ridge augmentation surgeries.

Methods: This double-blind split-mouth clinical trial was performed on patients needing implants with horizontal ridge augmentation (n=21). The control and intervention groups were considered split-mouth in two areas of the patients' oral soft tissues. A collagen membrane impregnated with ACS was used on the test side, and only a collagen membrane was used on the control side. After four months, histological changes in soft tissues, such as the amount of connective tissue collagen, fibroblast and inflammatory cell counts, and expression of the IL-1β gene, were evaluated.

Results: The fibroblast counts in the ACS group were significantly higher than in the control group. In addition, ACS caused a significant increase in the amount of collagen in the soft tissues compared to the control group (P<0.01). However, the number of inflammatory cells was similar in the two groups (P>0.05). IL-1β gene expression was not significantly different between the case and control groups.

Conclusion: Under the limitations of the present study and based on the results of histological examinations, ACS increased the number of fibroblasts and the amount of collagen in soft tissues without affecting inflammatory cells (P=0.562).