Document Type


Date of Degree

Summer 2013

Degree Name

MS (Master of Science)

Degree In

Oral Science

First Advisor

Hong, Liu

First Committee Member

Williamson, Anne E

Second Committee Member

Johnson, William T


Objective: An in vitro study to determine the age and gender related changes of dental pulp stem cells in regards to proliferative capacity and lineage dependent effects on differentiation capabilities.

Material and Methods: Specimens have been collected from a population ranging from 16 yrs of age to 78 yrs of age. Intact, non-carious teeth were collected from the oral surgery department at College of Dentistry at the University of Iowa. A total of 20 specimens were collected. Teeth were collected, sectioned and pulpal tissue collected from the specimens. The pulpal tissue was cut and stored in phosphate buffered saline. The tissue was then subjected to enzymatic digestion and DPSC isolation. Subsequently cell cultures were grown, percentage of Stro-1+ cells and proliferation rate were measured. The DPSC were subjected to differentiation via osteogenic and adipogenic medium. The cells were assessed for osteogenic and adipogenic characteristics using RT- PCR and also replicative senescence using telomere length ratio measurement.

Results: Data suggests that with increasing age, there is a decreased proliferative capacity, decreased osteogenic capacity and shortened telomere length. There is no difference in the adipogenic potential and the percentage of DPSC present. There appears to be no difference in DPSCs in regards to proliferative capacity and differentiation potential with regards to gender. A possible gender related effect was noted in osteogenic potential and telomere length.

Conclusion: Increasing age has both a decreased proliferative effect and lineage dependent effects on DPSC differentiation potential. Thus this relationship must be accounted for when developing future regenerative therapies.


vi, 60 pages


Includes bibliographical references (pages 53-60).


Copyright 2013 Rene Chu