In recent years ceramic and plastic materials have had an increased use with regards to dental restorations. These materials have a more natural appearance and are esthetically pleasing. They are used most commonly where they will be visible. Traditional materials such as gold and base metal alloys are commonly used in the back of the mouth. This area requires strength to withstand the forces of chewing. Direct restorative materials are the traditional amalgams and composites commonly known as a “filling”. Indirect restorative materials are made of materials such as porcelain (ceramic), porcelain fused to metal, gold alloys (high noble) and base metal alloys (non-noble). Please see the chart below to compare materials and principal uses, durability and other useful information.
Indirect Restorative Dental Materials
PORCELAIN Fused to metaL
GOLD ALLOYS (high noble)
BASE METAL ALLOYS (non-noble)
General Description Porcelain, ceramic or glass-like fillings and crowns. Porcelain is fused to an underlying metal structure to provide strength to a filling, crown or bridge. Alloy of gold, copper and other metals resulting in a strong, effective filling, crown or bridge. Alloys of non-noble metals with silver appearance resulting in high strength crowns and bridges.
Principal Uses Inlays, onlays, crowns and aesthetic veneers. Crowns and fixed bridges. Inlays, onlays, crowns and fixed bridges. Crowns, fixed bridges and partial dentures.
Leakage and Recurrent Decay Sealing ability depends on materials, underlying tooth structure and procedure used for placement. The commonly used methods used for placement provide a good seal against leakage. The incidence of recurrent decay is similar to other restorative procedures.
Durability Brittle material, may fracture under heavy biting loads. Strength depends greatly on quality of bond to underlying tooth structure. Very strong and durable. High corrosion resistance prevents tarnishing; high strength and toughness resist fracture and wear.
Cavity Preparation Considerations
Because strength depends on adequate porcelain thickness, it requires more aggressive tooth reduction during preparation. Including both porcelain and metal creates a stronger restoration than porcelain alone; moderately aggressive tooth reduction is required. The relative high strength of metals in thin sections requires the least amount of healthy tooth structure removal.
Clinical Considerations These are multiple step procedures requiring highly accurate clinical and laboratory processing. Most restorations require multiple appointments and laboratory fabrication.
Resistance to Wear Highly resistant to wear, but porcelain can rapidly wear opposing teeth if its surface becomes rough. Highly resistant to wear, but porcelain can rapidly wear opposing teeth if its surface becomes rough. Resistant to wear and gentle to opposing teeth. Resistant to wear and gentle to opposing teeth.
Resistance to Fracture Prone to fracture when placed under tension or on impact. Porcelain is prone to impact fracture; the metal has high strength. Highly resistant to fracture.
Biocompatibility Well tolerated. Well tolerated, but some patients may show allergenic sensitivity to base metals. Well tolerated. Well tolerated, but some patients may show allergenic sensitivity to base metals.
Sensitivity, if present, is usually not material specific.
Low thermal conductivity reduces the likelihood of discomfort from hot and cold. High thermal conductivity may result in early post-placement discomfort from hot and cold.
Esthetics Color and translucency mimic natural tooth appearance. Porcelain can mimic natural tooth appearance, but metal limits translucency. Metal colors do not mimic natural teeth.
Relative Cost to Patient Higher; requires at least two office visits and laboratory services. Higher; requires at least two office visits and laboratory services. Higher; requires at least two office visits and laboratory services.
Average Number of Visits To Complete Minimum of two; matching esthetics of teeth may require more visits. Minimum of two; matching esthetics of teeth may require more visits. Minimum of two
© American Dental Association. Updated, February 21, 2002