relationship between mast cell counts and different types of periodontitis

background and aims. mast cells play an important role in allergic reactions, host defense, local homeostasis, inflammation and angiogenesis. the aim of this study was to evaluate the relationship between mast cell counts and different types of periodontitis. materials and methods. gingival specimens were taken from 20 moderate-to-advanced chronic and 19 moderate-to-advanced aggressive periodontal sites as case groups and 18 healthy/gingivitis sites as control group in routine periodontal flap and crown lengthening procedures. all the specimens were stained by toluidine blue for mast cell counting and hematoxylin/eosin to assess inflammation. inflammatory and mast cells were assessed in 5-micron sections by two observers 3 times, utilizing light microscopy at ×100 and ×400 magnification. anova and t-test were used to analyze data. statistical significance was defined at α=0.05. results. mast cell counts were higher in chronic versus aggressive periodontitis and healthy/gingivitis cases (p = 0.000). the aggressive periodontitis cases did not demonstrate higher counts of mast cells as compared to healthy/gingivitis cases (p >0.05). there was no relationship between mast cell counts and degree of inflammation in the three groups. conclusion. the present study indicated higher mast cell counts in the chronic periodontitis sites compared to other sites. the results of this study suggest that further studies are necessary to simultaneously evaluate dynamic aspects of host defense and other aspects of immune system.