# In Vivo Evaluation of Decellularized Human Tooth Scaffold for Dental Tissue Regeneration
###### Abstract  
Conventional root canal treatment may result in loss of tooth vitality, which can lead to unfavorable treatment outcomes. Notably, a ceased tooth development of immature permanent teeth with open apices, regeneration of periodontal ligaments (PDL), and pulp is highly expected healing process. For regeneration, the scaffold is one of the critical components that carry biological benefits. Therefore, this study evaluated a decellularized human tooth as a scaffold for the PDL and pulp tissue regeneration. A tooth scaffold was fabricated using an effective decellularization method as reported in previous studies. PDL stem cells (PDLSCs) and dental pulp stem cells (DPSCs) obtained from human permanent teeth were inoculated onto decellularized scaffolds, then cultured to transplant into immunosuppressiveed mouse. After 9 weeks, PDLSCs and DPSCs that were inoculated onto decellularized tooth scaffolds and cultured in an in vivo demonstrated successful differentiation. In PDLSCs, a regeneration of the cement/PDL complex could be expected. In DPSCs, the expression of genes related to revascularization and the hard tissue regeneration showed the possibility of pulp regeneration. This study suggested that the potential possible application of decellularized human tooth could be a scaffold in regeneration PDL and pulp tissue along with PDLSCs and DPSCs, respectively, as a novel treatment method. decellularized tooth scaffold; dental pulp stem cell; periodontal ligament stem cell; tissue regeneration +
Footnote †:  
+++ ==WARNING: Truncated because of repetitions==
Footnote †: of the promising alternatives to the conventional treatment is concept of PDL and pulp regeneration [4; 5; 6; 7; 8]. Current concept of regeneration is composed of important factors such as cells, scaffolds, and growth factors [9; 10]. Stem cells (SCs) have the potential to proliferate, self-renew, and differentiate into a variety of functional cells [11]. Dental SCs (DSCs) are post-natal stem cells that have mesenchymal stem cell-like qualities, including the capacity for self-renewal and multi-lineage differentiation [12]. DSCs can be collected from craniofacial bones, dental follicles, tooth germs, dental pulp, PDL, apical papillae, oral mucosa, gingiva, and the periosteum [13]. Various DSCs are being studied for their therapeutic potential [12] including tooth repair [14]. Stem cells can play a role in tissue regeneration, but the cell conditions in the laboratory environment and in the original tissue are different. Various types of scaffolds are used in regenerative tissue engineering to enhance stem cell differentiation, proliferation, and metabolism [15]. Scaffolds could promote stem cell adhesion and proliferation by mimicking the microenvironments and supporting structures of tissues [16; 17]. Although more tissue regeneration research is being conducted nowadays, tissue repairs are still more common than tissue regeneration. After injection of suspended stem cells, it is almost impossible to control cell location and function, so a suitable scaffold is required. In particular, extracellular matrix (ECM) is important for scaffold fabrication and selection for reasons such as biological compatibility, biological degradability, and the possibility of rapid remodeling in vivo [18]. Synthetic scaffold using CAD/CAM technologies, laser-assisted bioprinting technologies, and a scaffold using decellularized organs are being studied to improve the effectiveness of tissue regeneration [19; 20] including dental tissue regeneration [21]. Among the available dental scaffolds, decellularized tissues, decellularized human tooth, and tooth bud scaffolds were studied as a promising dental tissue regeneration scaffolds in current studies [22; 23; 24]. Moreover, the results of dental tissue regeneration are affected by the delivery of growth factors. Studies on regeneration associated with the interaction between the dental or nondental stem cells and the growth factors under in vivo environment have been recently reported [2; 25; 26].