Dental Filling Facts

Toxicity of Dental Materials

Dental Amalgam

Mercury in its elemental form is on the State of California's Proposition 65 list of chemicals known to the state to cause reproductive toxicity. Mercury may harm the developing brain of a child or fetus.

Dental amalgam is created by mixing elemental mercury (43 - 54%) and alloy powder (46 - 57%) composed mainly of silver, tin, and copper. This has caused discussion about the risks of mercury in dental amalgam. Such mercury is emitted in minute amounts as vapor. Som concerns have been raised regarding possible toxicity. Scientific research continues on the safety of dental amalgam. According to the Center for Disease Control and Prevention, there is scant evidence that the health of the vast majority of people with amalgam is compromised.

The Food and Drug Administration and other public health organizations have investigated the safety of amalgam used in dental fillings. The conclusion: no valid scientific evidence has shown that amalgams cause harm to patients with dental restorations, except in rare cases of allergy. The World Health Organization reached a similar conclusion.

A diversity of opinions exist regarding the safety of dental amalgams. Questions have been raised about its safety in pregnant women, children, and diabetics. However, scientific evidence and research literature in peer-reviewed scientific journals suggest that otherwise healthy women, child's, and diabetics are not at an increased risk from amalgams in their mouths. The FDA places no restrictions on the use of dental amalgam.

Composite Resin

Some Composite Resins include Crystalline Silica, which is on the State of California's proposition 65 list of chemicals known to the state to cause cancer.


Dental Materials -Advantages & Disadvantages

Dental Amalgam Fillings

Dental amalgam is a self-hardening mixture of silver-tin-copper alloy powder and liquid mercury and is sometimes referred to as silver fillings because of its color. It is often used as a filling material and replacement for broken teeth.

Advantages:
Durable: long lasting
Wears well: holds up well to the forces of biting
Relatively inexpensive
Generally completed in one visit
Self-sealing: minimal to no shrinkage and resists leakage
Resistance to further decay is high, bit can be difficult to find in early stages
Frequency of repair and replacement is low

Disadvantages
Grey colored, not tooth colored
May darken over time as it corrodes: may stain the tooth over time.
Requires removal of some healthy tooth
In larger amalgam fillings the remaining tooth may weaken and fracture
Because metal ca conduct hot and cold temperatures there may be temporary sensitivity
Contact with other metals may cause occasional, minute electrical flow


Composite Resin Fillings

Composite fillings are a mixture of powdered glass and plastic resin, sometimes referred to as white, plastic, or tooth-colored fillings. It is used for fillings, inlays, veneers, partial and complete crowns, or to repair portions of broken teeth.

Advantages
Strong and durable
Tooth colored
Single visit for fillings
Resists breaking
Maximum amount of tooth preserved
Small risk of leakage if bonded only to enamel
Does not corrode
Generally holds up well to the forces of biting depending on product used
Resistance to further decay is moderate and easy to find
Frequency of repair or replacement is low to moderate

Disadvantages
Refer to "What About the Safety of Filling Materials"
Moderate occurrence of tooth sensitivity; sensitive to dentist's method of application
Coats more than dental amalgam
Material shrinks when hardened and could lead to further decay and/ or temperature sensitivity
Requires more than one visit for inlays, veneers, and crowns
May wear faster than dental enamel
May leak over time when bonded beneath the layer of enamel

GLASS IONOMER CEMENT

Glass ionomer cement is a self hardening mixture of glass and organic acid. It is tooth-colored and varies in translucency. Glass ionomer is usually used for small fillings, cementing meta and porcelain/ metal crowns, liners, and temporary restorations.

Advantages
Reasonably good esthetics
May provide some help against decay because it releases fluoride
Minimal amount of tooth needs to be removed and it bonds well to both the enamel and the dentin beneath the enamel
Materials has low incidence of producing tooth sensitivity
Usually competed in one dental visit

Disadvantages
Cost is very similar to composite resin (which costs more than amalgam)
Limited use because it is not recommended for biting surfaces in permanent teeth
As it ages, this material may become rough and could increase the accumulation of plaque and chance of periodontal disease
Does not wear well; tends to crack over time and can be dislodged

RESIN-IONOMER CEMENT

Resin ionomer cement is a mixture of glass and resin polymer and organic acid that hardens with exposure to a blue light used in the dental office. It is tooth colored but more translucent than glass ionomer cement. It is most often used for small fillings, cementing metal and porcelain metal crowns and lines.

Advantages
Very good esthetics
May provide some help against decay because it releases fluoride
Minimal amount of tooth needs to be removed and it bonds well to both the enamel and the dentin beneath the enamel
Good for non-biting surfaces
May be used for short-term primary teeth restorations
May hold up better than glass ionomer but not as well as composite
Good resistance to leakage
Material has low incidence of producing tooth sensitivity
Usually completed in one dental visit

Disadvantages
Cost is very similar to composite resin (which costs more than amalgam)
Limited use because it is not recommended to restore the biting surfaces of adults
Wears faster than composite and amalgam

PORCELAIN (CERAMIC)

Porcelain is a glass-like material formed into fillings or crowns using models of the prepared teeth. The material is tooth-colored and is used in inlays, veneers, crowns and filled bridges.

Advantages
Very little tooth needs to be removed for use as a veneer; more tooth needs to be removed for a crowns because its strength is related to its bulk (size)
Good resistance to further decay if the restoration fits well
Is resistant to surface wear but can cause some wear on opposing teeth
Resists leakage because it can be shaped for a very accurate fit
The material does not cause tooth sensitivity

Disadvantages
Material is brittle and can break under biting forces
May not be recommended for molar teeth
Higher cost because it requires at least two office visits and laboratory services

NICKEL OR COBALT-CHROME ALLOYS

Nickel and cobalt-chrome alloys are mixtures of nickel and chromium. They are a dark silver metal color and are used for crowns and fixed bridges and most partial denture frameworks.

Advantages
Good resistance to further decay if the restoration fits well
Excellent durability; does not fracture under stress
Does not corrode in the mouth
Minimal amount of tooth needs to be removed
Resists leakage because it can be shaped for a very accurate fit

Disadvantages
Is not tooth colored; alloy is a dark silver metal color
Conducts heat and cold; may irritate sensitive teeth
Can be abrasive to opposing teeth
High cost; requires at least two office visits and laboratory services
Slightly higher wear to opposing teeth

PORCELAIN FUSED TO METAL

This type of porcelain is a glass-like material that is "enameled" on top of metal shells. It is tooth-colored and is used for crowns and fixed bridges

Advantages
Good resistance to further decay if the restoration fits well
Very durable, due to metal substructure
The material does not cause tooth sensitivity
Resists leakage because it can be shaped for a very accurate fit

Disadvantages
More tooth must be removed (than for porcelain) for the metal substructure
Higher cost because it requires at least two office visits and laboratory services

GOLD ALLOY
Gold alloy is a gold-colored mixture of gold, copper, and other metals and is used mainly for crowns and fixed bridges and some partial denture frameworks

Advantages
Good resistance to further decay if the restoration fits well
Excellent durability; does not fracture under stress
Does not corrode in the mouth
Minimal amount of tooth needs to be removed
Wears well; does not cause excessive wear to opposing teeth
Resists leakage because it can be shaped for a very accurate fit

Disadvantages
Is not tooth colored; alloy is yellow
Conducts heat and cold; may irritate sensitive teeth
High cost; requires at least two office visits and laboratory services

Dental Board of California
1432 Howe Avenue, Sacramento, California 95825
www.dbc.ca.gov
Published by California Department of Consumer Affairs
5/04

 
 
Contact Us
antispam