Cytomorphometric and Clinical Changes in Gingival Tissue after Subgingival Tooth Preparation—A Pilot Study

Tooth preparation for a metal-ceramic crown with a subgingival finish line can lead to inflammatory changes in the gingival tissue, often accompanied by cell damage. This study aimed to evaluate the clinical signs of inflammation and the cytomorphological status of the gingival tissue before and after tooth preparation. The research included a homogeneous group of 19 patients with an indication for upper canine preparation. Before and after treatment, the gingival and the gingival bleeding indexes were determined, gingival swabs were taken, and direct smears prepared on slides for cytomorphometric analysis. The values of the measured gingival indexes were statistically significantly higher (p < 0.001) after tooth preparation. They decreased over time, which indicated the reversibility of the resulting changes. Cytological examination showed no statistically significant difference between the values of nuclear area, perimeter, Feret diameter, Feret angle, integrated optical density, MinFeret, and roundness, before and after the treatment. Significantly higher values of circularity, integrated optical density, MinFeret (p < 0.05), as well as roundness (p < 0.001) were found after 72 h, compared to those taken 15 min after tooth crown preparation. This study is a pioneering attempt to show gingival changes during fixed prosthodontic treatment and may shed new light on pathogenetic events in prosthodontic patients.