Adhesion of living cells to abutment materials, dentin, and adhesive luting cement with different surface qualities

- A new testing method for researching real “cell-attachment” of living cells is proposed.
- Human dentin could be established as a gold standard for this testing method.
- Zirconium dioxide, titanium and lithium disilicate are comparable abutment materials with regard to cell adhesion.
- Machined - not polished or roughened - abutment surfaces provide the best cell attachment.
- The resin cement of two-piece abutments does not pose a problem for cell adhesion.

ObjectiveWe tested the adhesion properties of living gingival fibroblasts on three different implant abutment materials, adhesive resin used to bond bi-partite abutments, and human dentin.MethodsDiscs of lithium disilicate (LS), zirconium dioxide (Zr), adhesive resin cement (AR), titanium (Ti), and human dentin (HD) were fabricated with three different levels of surface roughness (rough, machined, and polished). Ra and Rz, water contact angle, and cell detachment forces were measured. Cell detachment force was measured for single cells using single-cell force spectroscopy. Data were statistically analyzed using parametric tests (ANOVA, MANOVA, Bonferroni post-hoc tests).ResultsSurface roughness significantly influenced the water contact angle for all materials (P ≤ 0.05). Overall, HD showed the lowest contact angle, followed by LS, Ti, Zr, and AR (P ≤ 0.05). Comparison of cell detachment forces between materials with rough and machined surfaces revealed no significant differences (P > 0.05), with the exception of Zr compared to HD with rough surfaces (P = 0.006). For polished surfaces, HD showed the highest detachment force (P ≤ 0.0001), followed by Ti, AR, and Zr, which did not significantly differ from each other (P > 0.05) and LS; Ti/AR was significantly different from LS (P ≤ 0.05). Except for HD, where polished surfaces exhibited the highest cell detachment force (P ≤ 0.002), most machined surfaces showed higher cell detachment forces than polished or rough surfaces.SignificanceImplant abutments should ideally be provided with a machined like surface roughness for best cell adhesion.