(PR21) Cryopreservation of Pulp Tissue and Its Scope in Regenerative Endodontics

Thursday, April 28, 2022

1:00 PM – 4:00 PM PST

Location: Exhibit Hall

Presenter(s)

DHRUVI PATEL, B.D.S.

RESIDENT
University of California, Los Angeles
LOS ANGELES, California, United States

Co-Author(s)

Mo Kang, D.D.S., M.S., Ph.D.

Professor and Chair
University of California, Los Angeles
Los Angeles, California, United States
Wei Chen, M.S., Ph.D.

N/A
University of Alberta
Los Angeles, California, United States
AA

Abdullah Alshaikh, B.D.S., M.S.

Resident
University of California, Los Angeles
Los Angeles, California, United States

Abstract:

Objectives: Pulp tissue as a source of MSCs has popularized the scope of regenerative endodontics. However, unlike cord tissue banking, no studies have established the conditions to preserve the pulp tissue. The purpose of our study was to demonstrate that cryopreserved pulp can maintain its stem cell potential. Materials and

Methods: To identify the ideal freezing medium, 4 variables were selected as the experimental group. Unfrozen tissue was used as a positive control and frozen tissue without any cryoprotectant was used as a negative control. To determine the differentiation potential, odontogenic differentiation assays, ARS and ALP, were performed and expression of odontogenic markers, such as Collagen 1 and 3 were examined by real-time polymerase chain reaction (RT-PCR). Histologic examination was completed to study the cell migration pattern in vitro using a 3D dentin slice model and to observe the perivasculature in MSCs derived from minced pulp (MPMSCs).

Results: No phenotypic changes were observed between the frozen tissue as compared to control. Histologic examination showed cell migration was same as control group on the dentin slice model. No significant difference in the odontogenic potential of frozen tissue was seen. IHC staining of cells derived from the minced pulp tissue revealed that they maintained the intact perivascular niche and showed expression of NG2 and PDGFrβ.

Conclusion: Pulp tissue can retain its MSCs characteristics after recovery from freezing conditions.