Abstract
Background:
Azathioprine is one of the earliest immunosuppressants prescriped for several autoimmune diseases. Yet there is a lack of research on the impact of azathioprine on pulp healing following pulp capping procedure.
Aim:
This study aimed to investigate the effect of azathioprine on the healing ability of mechanically exposed dogs' dental pulps following direct pulp capping with Mineral Trioxide Aggregate (MTA), Bio-Aggregates (BA), and Calcium hydroxide (Ca(OH)2).
Methods:
Four mongrel dogs were randomly assigned to two groups (2 dogs/30 teeth in each group): immunosuppressed (group I) and control (group II). Group I received azathioprine for two months before surgical treatments and until the dogs were euthanized. Fifteen class V buccal cavities were performed in each dog. Each group was randomly divided into three subgroups (10 teeth each) based on the pulp capping substance. The pulps in subgroups A, B, and C were immediately capped with MTA, BA, and Ca(OH)2, respectively. Inflammation and dentine bridge development were histopathologically evaluated and scored at one and two months. The data were statistically analyzed.
Results:
The immunosuppressed group exhibited statistically greater inflammatory cell count and decreased dentine bridge thickness, compared to the control group in all subgroups (P<0.05).
Conclusion:
Azathioprine has an adverse effect on the healing of exposed dogs' dental pulp following direct pulp capping with MTA, BA, and Ca(OH)2. Therefore, patients using azathioprine as an immunosuppressive medication may experience delayed healing of mechanically exposed pulps following capping with MTA, BA, or Ca(OH)2.

Key words: Bio-Aggregates, Calcium hydroxide, Dentine bridge, Immunosuppression, Mineral trioxide aggregate