Use of titanium in dentistry and medicine has increased in recent decades. Although porcelain fused to a metal crown is usually used as a technique for dental restorations, titanium’s insufficient bond strength with porcelain yields inferior dental applications. The oxide layer produced on titanium was considered to have a potentially adverse effect on titanium-porcelain bonding. This article reviews studies published recently on the effects of oxidation of titanium on the bonding strength of titanium and porcelain.