Abstract: Dental restorations need to reproduce the aspect of the natural teeth of the patient, and
must be non-toxic, biocompatible, and have good mechanical properties so that they can last for
longer. The aim of this study was to determine the extent of bacterial adhesion of Streptococcus mutans
on four different dental material surfaces, i.e., two glass–ionomer cements (Fuji conventional and
Fuji hybrid) and two ceramic composites (Micro hybrid composite and Nano hybrid composite). To
understand the bacterial adhesion on these four different dental materials, various surface properties
were measured: roughness, contact angle, CIE color parameters and zeta potential. We found that
the greatest adhesion extent was obtained for the Nano hybrid composite surface. The pronounced
adhesion is the interplay between the relatively high roughness and hydrophilicity of the Nano
hybrid composite surface. Color changes upon immersing ceramic composites in red wine and black
tea proved that both beverages adhered to them. Black tea adhered more intensively than wine, and
showed a higher inhibitory effect on the growth of Streptococcus mutans and Staphylococcus aureus.