Flow cytometry for assessing pulp viability in pediatric dentistry: An exploratory study
Josué Zuriel Ortiz García1, Ismael Secundino1, José Luis Ayala Herrera1
1Research Department, Faculty of Dentistry, La Salle Bajío University, León, Guanajuato, Mexico.
Background:
Dental pulp (DP) in pediatric patients plays a vital role in dentin formation, nutrition, protection, and tooth repair. Pulpal pathologies are a common reason for pediatric dental visits; however, accurate clinical diagnosis can be challenging, particularly in young patients and those with limited cooperation. Currently, no reliable clinical method exists to definitively determine pulp viability, and histopathological diagnosis remains the gold standard despite its invasiveness. Flow cytometry has proven effective in cellular analysis across biomedical fields and was used in this study to assess pulp viability in pediatric patients with various pulpal conditions.
Methods:
Forty-four pulp samples from pediatric patients aged 2-7 years were classified as healthy pulp (HP), reversible pulpitis (RP), irreversible pulpitis (IP), and pulp necrosis (PN). Flow cytometry using 7-aminoactinomycin D (7-AAD) staining was employed to assess cell viability. Total protein extracts were obtained from each group for SDS-PAGE analysis of protein profiles. Proteolytic activity was evaluated through gelatin zymography to detect matrix metalloproteinase (MMP) activity.
Results:
Flow cytometry effectively quantified viable cells across diagnostic categories, revealing minimal differences in viability between HP, RP, and IP, which may explain the clinical challenge of differentiating these conditions. Protein profile analysis showed a progressive reduction in the number of protein bands as pulpal disease advanced, although some bands remained consistent. Proteolytic activity, likely associated with MMP-2, increased with disease progression and was significantly elevated in PN compared to other groups.
Conclusion:
Flow cytometry proved a valuable tool for quantifying pulp cell viability in pediatric patients, highlighting the narrow clinical distinction between pulpal conditions. Protein profiling suggests the potential to identify diagnostic biomarkers that support less invasive diagnostic approaches. Although matrix metalloproteinase-2 (MMP-2) activity was present in all stages of pulpal disease, it could not be confirmed as a specific biomarker for disease progression.
