IADR Abstract Archives
Age-Related Expression of CD34 in Human Dental Pulp Cells
Objectives: The expression of the human hematopoietic progenitor cell antigen CD34 is a valuable marker mirroring the vessel and network structures in response to functional needs and dental tissue homeostasis. The aim of the study is to examine and compare the age-related immunohistochemical distribution of CD34 in human dental pulp.
Methods: Ninety freshly extracted intact teeth of healthy individuals were enrolled in the study and arranged in three groups (n=30 in each group) regarding the patients’ age: young (14-16 years old), adult (18-40 years old) and senescent (41-78 years old) groups. All teeth were indicated for surgery due to limited jawbone space for eruption (third molars) or periodontal and bone lost (premolars and incisors). Immediately after extraction the molars were fixed overnight in 10% buffered paraformaldehyde and reduced in size by trimming the enamel, superficial coronal dentin and the roots up to 2mm below the CEJ. The coronal dentin-pulp specimens were decalcified in a 3% hydrochloric acid (HCl) for 6 hours and paraffin embedded. Immunohistochemistry using mouse monoclonal antibody CD34 (B-6), Santa Cruz Biotechnology Inc., USA was performed by Leica-Bond Max automated system (Leica Biosystems, Germany). Statistical analysis including Kruskal-Wallis and Mann-Whitney tests were performed (p<0.05).
Results: A higher number of immunolabeled sections for CD34 were found in all examined groups without significant difference between the adult and senescent groups compared to the young group (p>0.05). In aging pulp, vascularization was not reduced, the density of the vascular network was maintained. Numerous small blood vessels with well-formed walls and CD34 immunopositive endothelial cells were observed throughout the pulp thus revealed the process of vasculogenesis persists into adult life.
Conclusions: Immunohistochemical distribution of CD34+ endothelial cells in all age groups supports the concept of constant angiogenesis in the adult's body, renewal of the vascular network of the dental pulp throughout the life and continuous angio-adaptation.
Methods: Ninety freshly extracted intact teeth of healthy individuals were enrolled in the study and arranged in three groups (n=30 in each group) regarding the patients’ age: young (14-16 years old), adult (18-40 years old) and senescent (41-78 years old) groups. All teeth were indicated for surgery due to limited jawbone space for eruption (third molars) or periodontal and bone lost (premolars and incisors). Immediately after extraction the molars were fixed overnight in 10% buffered paraformaldehyde and reduced in size by trimming the enamel, superficial coronal dentin and the roots up to 2mm below the CEJ. The coronal dentin-pulp specimens were decalcified in a 3% hydrochloric acid (HCl) for 6 hours and paraffin embedded. Immunohistochemistry using mouse monoclonal antibody CD34 (B-6), Santa Cruz Biotechnology Inc., USA was performed by Leica-Bond Max automated system (Leica Biosystems, Germany). Statistical analysis including Kruskal-Wallis and Mann-Whitney tests were performed (p<0.05).
Results: A higher number of immunolabeled sections for CD34 were found in all examined groups without significant difference between the adult and senescent groups compared to the young group (p>0.05). In aging pulp, vascularization was not reduced, the density of the vascular network was maintained. Numerous small blood vessels with well-formed walls and CD34 immunopositive endothelial cells were observed throughout the pulp thus revealed the process of vasculogenesis persists into adult life.
Conclusions: Immunohistochemical distribution of CD34+ endothelial cells in all age groups supports the concept of constant angiogenesis in the adult's body, renewal of the vascular network of the dental pulp throughout the life and continuous angio-adaptation.