Table 1.

The list and potential applications of metallic oxide compounds used in restorative dentistry.

Metallic Oxide	Potential Applications
Titanium Dioxide (TiO2)	-TiO2 nanoparticles improved the antibacterial properties against caries-related pathogens [54] -TiO2 enhanced the hardness and strength of resin-based materials [55] -TiO2 enhances the polymerization kinetics [56] and photo-catalytic activities [57]
Zinc Oxide (ZnO)	-ZnO nanoparticles improved the antibacterial properties against single [58] and multispecies biofilms [59] -Tetrapod-like zinc oxide whisker improved the mechanical properties of the designed resin composite [60]
Copper Oxide (CuO)	-Copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC)-based resins reduced the growth of S. mutans biofilms [61] and improved the mechanical and polymerization properties [62]
Iron Oxide (Fe2O3)	-Fe2O3 improved the µ-tensile [63] and shear bond strength [64] of a dental adhesive
Cerium Oxide (CeO2)	-CeO2 significantly improved the radiopacity of dental adhesive [65], which can facilitate the differentiation between secondary caries and the adhesive layer
Tantalum Oxide (Ta2O5)	-Ta2O5 improved the fracture toughness of the designed materials [66,67] -Ta2O5 improved the radiopacity of a dental adhesive [68] -Ta2O5 quantum dots in dental adhesive inhibited the growth of S. mutans biofilm [69]
Niobium Pentoxide (Nb2O5)	-Nb2O5 improved the radiopacity of a dental adhesive [70]
Zirconium Oxide (ZrO2)	-ZrO2 can enhance the optical properties of resin composite restorations [71] -ZrO2 improved µ-tensile bond strength of dental adhesive [72]