Background
In recent years, implant dentistry has become a reliable common therapy standard for edentulous patients.
However, implant placement is often restricted by bone volume of edentulous site.
Although autogenous bone grafting is a gold standard, there are disadvantages such as increased invasiveness by bone collection and limited collection site.
Therefore we focused on dissociated soft tissue and hypothesized that it enhances osteogenesis and have a beneficial effect on bone augmentation.

Materials and Methods
Six-week-old male Slc:Wistar/ST rats (Sankyo Lab, Tokyo, Japan) were used in this study.
Rat bone marrow cells were harvested from femur bone and cultured to assess the stimulation of cell proliferation and differentiation.
Harvested palatal mucosa was dissociated using a device (Rigenerra; Human Brain Wave)
and was cultured with rat bone marrow cells by interposing
porous membrane (Cell Culture Insert; Thermo Fisher Scientific).
Cell proliferation and differentiation were assessed after one, three and seven days of culturing.
Cell proliferation was assessed by quantifying the absorbance of a water-soluble tetrazolium salt using Cell Counting Kit-8(Dojindo, Kumamoto, Japan)
Cell differentiation was assessed by alkaline phosphatase staining and real-time polymerase chain reaction.
Mineralized nodule formation was assessed by Alizarin red staining.

Aim
The Aim of this study was to evaluate the effects of dissociate soft tissue on bone marrow cell proliferation and differentiation by interposing porous membrane under osteogenic condition.
 
RESULTS
At day 1, cell proliferation activity were significantly higher in the experimental group than that of control group.
The relative expression levels of alkaline phosphatase was significantly higher in the experimental  group than in the control group on day 3, 7.
The relative expression levels of Type 1 collagen was significantly higher in the experimental  group than in the control group on day 1.
The relative expression levels of osteocalcin was significantly higher in the experimental  group than in the control group on day 7.
Mineralized nodules were observed in both group after three or seven days in culture by Alizarin red staining.
Statistically significant differences were observed in the mineralized nodule area between the experimental group and control group  on day 7.
Alkaline phosphatase staining tended to be strongly stained with the passage of time.

Conclusion and Clinical implication
This study demonstrated that cell proliferation, differentiation and mineralized nodule formation are promoted by dissociated soft tissue in indirect co-culture condition by interposing porous membrane.
This suggested that the dissociated tissue is effective for bone augmentation.
In addition, low invasiveness can reduce patient morbidity and expand the possibility of collecting sites.
Further studies are required to investigated the signaling molecules involved in dissociated soft tissue.

Osteogenic Property of Dissociated Soft Tissue in Indirect Co-culture System- In vitro study