Background and purpose: Periodontitis and gingivitis are inflammatory diseases in supporting tissues of tooth. Mast cells are inflammatory cells that can participate in destruction of connective tissue in periodontal diseases. In this study we evaluated mast cells count in gingival tissues in individuals with periodontal diseases and compared that with those in healthy people.

Materials and methods: This case-control study was done in 60 samples obtained from patients with advanced periodontitis (n=15), moderate periodontitis (n=15), gingivitis (n=15), and healthy tissue samples (n=15, control group). Biopsy specimens obtained during flap and crown lengthening surgery were stained with toluidine blue and hematoxylin eosin.

Results: Mast cells count were significantly different between four groups (P<0.001). In fact a significant difference was found in healthy status compared to that in moderate periodontitis, advanced periodontitis and gingivitis (P<0.001) but it did not show any significant difference in advanced and moderate periodontitis compared with that in gingivitis (P>0.05). Also, mast cells count did not reveal any significant difference between advanced periodontitis and moderate periodontitis (P>0.05). Moreover, we found no significant relationship between mast cells count and degree of microscopic inflammation (P=0.09)

Conclusion: Mast cells are believed to play a role in pathogenesis of periodontal diseases, but further studies are suggested to clarify this role.