Cytomorphometry is used in the sampling of biological materials and diagnostic procedures. The use of cytological studies in periodontal diseases is not well described in the literature. Our study aimed to quantitatively assess the inflammation dynamics using cytomorphometric analysis of the periodontium before and after the use of fixed dental prostheses. Following ethics approval, a total of 105 subjects were divided in 3 groups as gingivitis (n = 23), periodontitis (n = 58), and healthy periodontium (control) (n = 24). The fixed dental prostheses (crowns and fixed partial dentures) were fabricated from cobalt-chrome metal-ceramic prostheses using the conventional method (C/M-CoCr), cobalt-chrome metal-ceramic prostheses by the computer-aided design and computer-aided manufacturing (CAD/CAM) technique (C/C-CoCr), and zirconia-based ceramic prostheses by the CAD/CAM technique (C/C-Zr) among subjects with gingivitis and periodontitis. The gingival crevicular fluid (GCF) was obtained from subjects before and after the use of the prostheses. The total count of epithelial cells and the connective tissue cells or polymorphonuclear neutrophils (PMNs) in GCF were studied using cytomorphometric analysis. The Statistical Package Tor the Social Sciences (SPSS), Version 20 (IBM Company, Chicago, IL, USA) was used to analyze the results and the significance level was set at p = 0.05. The data for before and after the use of the prostheses were compared using independent t-Tests. Similarly, the results after the use of prostheses in gingivitis, periodontitis, and control in each type of prostheses were compared using One-way ANOVA with post hoc using Scheffe. The total epithelial cells and the PMNs were determined along with the epithelium/leukocyte index. Regardless of the prostheses type used, no significant change in the parameters was identified among patients with a healthy periodontium, before and after prosthetic treatment. In all study groups, a statistically increase (p value < 0.05) was observed in the oral epithelial cell counts and a statistically decrease (p < 0.05) in the PMNs count following the use of the fixed prostheses. Data on cytomorphometric analysis could enable the selection of the most appropriate prostheses for use in patients with periodontal pathologies. When choosing prostheses, changes in the composition of GCF could be considered as a useful criterion for their use.