Table 1.

Main instructive polymer scaffolds for different levels of endodontic regeneration.

Scaffold	Method	Associated Tissue Engineering Strategy		Regeneration Level *					Findings	Reference
Peptide-amphiphile (PA) hydrogel self-assembling	In vitro	-	DPSCs & SHEDs human	1					Easy for endodontic insertion Stem cell proliferation	Galler et al., 2008 [41].
Peptide hydrogel	In vivo	VEGF, TGF-β1 & FGF-1	DPSCs human	1	2	3			Release of VEGF, TGF-β1 and FGF-1 Odontoblast- like cell differentiation Pulp-like tissue formation	Galler et al., 2011 [42].
Peptide hydrogel multidomain peptides (MDP) self-assembling	In vitro	FGF, TGF-β1 &VEGF	DPSCs human	1		3			Pulp-like tissue formation	Galler et al., 2012 [43].
PCL	In vivo	Neural growth factor	mouse					5	Promotion of Innervation in a model of bioengineered tooth	Eap et al., 2014 [56].
Polydioxanone II (PDS II)	In vitro	MET or CIP	hDPSCs Human	1					Release MET or CIP Antimicribial activity against Ef and Pj	Bottino et al., 2013 [57].
Collagen	In vivo	BMP-2 and 4 & TGF-β1	Dog	1	2				BMP-2 and 4 induce osteodentin formation if combined with collagen matrix	Nakashima, 1994 [58].
	In vivo	CP & DMP-1	DPSCs human	1					New pulp-like tissue formation and organization human	Prescott et al., 2008 [59].
	In vivo	SDF-1	Dog pulp CD 105+, CD31 SP cells	1					Complete pulp-like tissue regeneration	Nakashima & lohara 2011 [60].
	In vivo	SDF-1	Dog pulp CD105+ cells	1		3	4		Complete pulp-like tissue regeneration Vascularization and innervation	Iohara et al., 2011 [61].
	In vivo	SDF-1	Dog pulp, BM, Adipose CD31 SP cells	1		3	4		Complete pulp-like tissue regeneration Vascularization and innervation	Ishizaka et al., 2012 [62].
	In vivo	G-CSF	hDPSCs human	1	2				Pulp-like tissue formation Differentiation of hDPSCs	Murakami et al., 2013 [63].
	In vivo	G-CSF	Dog mobilized DPSCs	1	2				Complete pulp-like tissue regeneration Coronal dentin formation in root canal	Iohara et al., 2013 [64].
	In vivo	G-CSF	Dog mobilized DPSCs	1					Differentiation of DPSCs Less volume of regenerated pulp-like tissue in aged dogs compared with that in young dog	Iohara et al., 2014 [65].
	In vitro	-	hDPCs	1	2				Beneficial effects on proliferation and differentiation of hDPCs	Kwon et al., 2017 [66].
Gelatin hydrogel	In vitro	FGF-2	Rat dental pulp	1		3			Release of FGF-2 Induces the invasion of dental pulp cells and vessels	Ishimatsu et al., 2009 [67].
Methacryloyl GelMA hydrogel	In vitro		OD21 ECFCs mouse	1		3			Cell viability, spreading and proliferation Simple and effective strategy for engineering of pre-vascularized dental pulp constructs	Athirasala et al., 2017 [68].
Fibrin gel	In vivo	PEG	DPSCs, SHEDs, PDLSCs BMSSCs human	1					All types of dental stem cells proliferated Easy for endodontic insertion	Galler et al., 2011 [69].
Platelet-rich fibrin (PRF)	In vitro	GFs	DPSC dog	1		3			Serve as a potential therapy in regenerative endodontics	Chen et al., 2015 [70].
	In vitro	GFs	hDPCs		2				Released the maximum quantity of growth factors	He et al., 2016 [71].
	In vitro	MTA	hDPCs		2				With MTA has a synergistic effects on odontoblastic differentiation of hDPCs	Woo et al., 2016 [72].
PRF or Platelet—rich plasma (PRP)	Clinical	-	human	1		3			PRP was better than PRF in peripheral wound healing when used in regenerative procedures	Shivashankar et al., 2017 [73].
Alginate hydrogel	In vitro	TGF-β1	human	1	2				Release of TGF-β1 Odontoblast-like cell differentiation	Dobie et al., 2002 [74].
Alginate hydrogel	In vitro	-	SCAPs	1					SCAPs proliferation	Lambricht et al., 2014 [75].
Alginate	In vitro	-	DPSCs human	1	2				Dental pulp mineralization Differentiation od DPSCs	Sancilio et al., 2018 [76].
Chitosan	In vitro	β-tricalcium phosphate	HPLCs human		2	3			Upregulated expressions of ALP and OPN	Liao et al., 2010 [77].
Chitosan	In vitro	1α,25-dihydroxyvitamin D3 (1α,25VD) Calcium-aluminate	DPCs human	1	2				Increased odontoblastic phenotype expression Cell migration	Bordini et al., 2019 [78].
Chitosan	In vitro	Silver Bioactive glass	DPCs	1	2				Decrease of inflammation Odontogenic differentiation of DPCs Inhibition of Streptococcus mutans and Lactobacillus casei growth	Zhu et al., 2019 [79].
Poly-L-lysine	In vitro	α-MSH	Rat-human	1					Poly-L-lysine (Dendrigraft) is favorable for colonization of pulp fibroblasts and to the delivery of anti-inflammatory hormone	Fioretti et al., 2010 [80]. Fioretti et al., 2011 [81].
Poly(L-lactic acid) PLLA	In vitro In vivo	-	DPSCs human	1					Attachment, proliferation and differentiation of DPSCs	Wang et al., 2011 [82].
PLGA	In vitro	-	DPCs human	1	2				Odontoblastic differentiation and proliferation	Zou et al., 2016 [83].
PLGA	In vitro	-	DPSCs	1					Differentiation of DPSCs	Gangolli et al., 2019 [84].

* Regeneration Levels; 1: Pulp Connective-tissue Formation, 2: Dentin Formation, 3: Revascularization, 4: Reinnervation, 5: Radicular Edification. Abbreviations: α-MSH: α-Melanocyte Stimulating Hormone, ALP: alkaline phosphatase, BM: bone marrow, BMP: bone morphogenetic protein, CIP: Ciprofloxacin, CP: ceramic powder, DMP-1: dentin matrix protein 1, DPSCs: dental pulp stem cells, ECFCs: endothelial colony forming cells, Ef: enterococcus faecalis, FGF-2: fibroblast growth factor 2, G-CSF: granulocyte colony-stimulating factor, GF: growth factor, hDPCs: human dental pulp cells, hDPSCs: human dental pulp stem cells, HPLCs: human periodontal ligament cells, MET: metronidazole, MTA: mineral trioxide aggregate, OD21: odontoblast-like cells, OPN: osteopontin, Pj: porphyromonas gingivalis, SDF-1: stromal-cell-derived factor-1, SHEDs: stem cells from human exfoliated deciduous teeth, SP: side-population, TGF-β1: transforming growth factor β 1, VEGF: vascular endothelial growth factor.