Allergic reactions are the most common type of adverse effect of dental materials.
Lichenoid reactions on the oral mucous membrane adjecent to amalgam restorations are the most frequently encountered side-effects for a specific group of restorative materials. Cost analyses were based on reports of longelivety of different restorations and the cost of restorations at the time of placement. Amalgam restorative therapy was more cost-effective than composite restorations and gold castings.