Histological Evaluation of Human Dental Pulp in a Tooth Crown Organ Culture

Objectives: The purpose of the study was to develop a new technique for tooth-crown organ culture and to evaluate the effect on the integrity of pulp tissue.
Methods: The crowns of 18 sound premolar teeth, freshly extracted for orthodontic reason were separated at CEJ level within one hour after extraction. All tooth crowns were randomly divided into three groups: control, 3-day and 7-day cultures. Each group was further subgrouped based on the method of crown preparation; intact or drilled crown techniques (to facilitate the flow of media). In the control group, teeth were fixed with 10% buffered formalin immediately after crown separation. In the cultured groups, teeth were cultured in sterile DMEM culture media either for 3 or 7 days. Thin paraffin-embedded crown sections were prepared, H&E stained and evaluated by a light microscope using the criteria modified from Ramazanzadeh et al. (2009).
Results: The results showed that the odontoblasts and pulp proper were mostly normal in the control group, regardless of the preparation technique. In the 3-day culture group, the intact-crown subgroup showed acceptable results with mild disruption of the odontoblastic layer whereas the drilled-crown subgroup showed moderate disruption of the odontoblastic layer with partial necrotic pulp proper. In the 7-day culture group, the odontoblastic layer was severely disrupted in both subgroups and were detached from predentine with partial necrotic pulp proper.
Conclusions: In conclusion, odontoblasts and pulp tissue could be best maintained up to 3 days in intact tooth crown culture and apparently, drilling the crown did not improve the quality of cultured pulp tissue.