Stem Cell Transplantation for Pulpal Regeneration: A Systematic Review

Abstract

For treating pulpal pathological conditions, pulpal regeneration through transplanted stem/progenitor cells might be an alternative to conventional root canal treatment. A number of animal studies demonstrated beneficial effects of stem/progenitor cell transplantation for pulp-dentin complex regeneration, that is, pulpal tissue, neural, vascular, and dentinal regeneration. We systematically reviewed animal studies investigating stem/progenitor cell-mediated pulp-dentin complex regeneration. Studies quantitatively comparing pulp-dentin complex regeneration after transplantation of stem/progenitor cells versus no stem/progenitor cell transplantation controls in intraoral in vivo teeth animal models were analyzed. The following outcomes were investigated: regenerated pulp area per root canal total area, capillaries per total surface, regenerated dentinal area per total defect area, and nerves per total surface. PubMed and EMBASE were screened for studies published until July 2014. Crossreferencing and hand searching were used to identify further articles. Standardized mean differences (SMD) and 95% confidence intervals (95% CI) were calculated using random-effects meta-analysis. To assess possible bias, SYRCLE's risk of bias tool for animal studies was used. From 1364 screened articles, five studies (representing 64 animals) were included in the quantitative analysis. Risk of bias of all studies was high. Stem/progenitor celltransplanted pulps showed significantly larger regenerated pulp area per root canal total area (SMD [95% CI]: 2.28 [0.35-4.21]) and regenerated dentin area per root canal total area ]) compared with no stem/progenitor cell transplantation controls. Only one study reported on capillaries per or nerves per total surface and found both significantly increased in stem/progenitor cell-transplanted pulps compared with controls. Stem/progenitor cell transplantation seems to enhance pulp-dentin complex regeneration in animal models. Due to limited data quantity and quality, current evidence levels are insufficient for further conclusions.

In Vivo Osteogenic Differentiation of Human Dental Pulp Stem Cells Embedded in an Injectable In Vivo‐Forming Hydrogel

“…[34][35][36][37] Recently, we have reported an injectable in vivoforming PC hydrogel for both in vitro and in vivo applications resulted in noninvasive surgeries. [21][22][23][24][25] In addition, both in vitro-and in vivo-forming PC hydrogel maintained their structure for at least ten months with little degradation. [ 38,39 ] into rats using a 21-gauge needle.…”

“…[24][25][26][27][28][29] Harvesting of hDPSCs has no or little practical constraints even though removal of teeth is painful. Such harvesting can be a convenient method since it allows the obtainment of a significant number of cells per patient.…”

Stem Cells of Dental Origin: Current Research Trends and Key Milestones towards Clinical Application

“…Current pulp regeneration protocols have also been recently systematically reviewed by Fawzy El-Sayed et al [30]. From 1364 screened articles the authors selected five studies for the quantitative analysis complying to specific inclusion/exclusion criteria.…”

“…In vivo studies, mostly in ectopic but less often in orthotopic animal models, have supported their potential to reconstitute functional dentin/pulp complexes when mixed with ceramic substrates (such as, Hydroxyapatite Or Tricalcium Phosphate) [29, 30], as well as other tissues, such as bone [31], cementum [32], blood vessels [33–35], and neural tissues [36, 37]. Most recently, attention has been focused on the biological properties of the plethora of soluble trophic and immunomodulatory cytokines produced by dental MSCs (MSC secretome) because of their angiogenic, neurogenic, and tissue repair properties [38].…”

Nanomaterials for Tissue Engineering In Dentistry

“…In the cell transplantation, the stem cells are isolated, cultivated in vitro, increased in number, inserted in soft scaffolds or hydrogels with or without addition of signaling molecules and calcium-phosphate nanoparticles and at last implanted in the receiving site, the empty and sterile endodontic space [140,141,142,143,144,145,146,147,148,149,150,151,152]. Instead, in the cell homing, where it is not necessary to isolate and manipulate in vitro stem cells, it is tried to reach pulpodentinal complex regeneration through the stimulation of residual stem cells by means of molecules veicolate by hydrogels [153,154,155].…”