Comparative evaluation of human oral fibroblast proliferation on 3D-printed zirconia and silicon nitride as new ceramic materials for implant abutment.

Purpose: Cell adhesion and subsequent proliferation on material surfaces depend on the physical and chemical characteristics of the material. There is a lack of literature on human gingival fibroblast proliferation on comparatively newer additively manufactured materials like silicon nitride. This study focused on the physical characteristics of the materials with the aim to compare the adhesion and proliferation of human gingival fibroblasts on additively manufactured silicon nitride (AMSN) with additively manufactured zirconia, conventional milled titanium (MTi), and milled zirconia.

Materials and methods: Surface roughness and water contact angle were measured by profilometer and goniometer, respectively. CCK-8 assay was done to assess the cell growth at 24 h (day 1), 48 h (day 2), and 72 h (day 3) in the same well. The morphologies of fibroblasts after cell attachment and proliferation were evaluated using scanning electron microscopy (SEM) after 72 h.

Results: At the end of 24 h (day 1) additively manufactured zirconia showed the best proliferation among the experimental groups, which was around 50% of the positive control group proliferation. There was no statistically significant difference among the experimental groups. At 48 h (day 2) and 72 h (day 3), a loss of cell growth was seen in almost all the experimental group wells. A positive cell proliferation on the AMSN was observed on day 3.

Conclusion: Comparable cell proliferation was observed in the experimental groups. No conclusive correlation could be drawn between cell proliferation and surface roughness and water contact angle values in the experimental groups.