Dental Restorations

The filling is a replacement of the hole (cavity) in the tooth structure after tooth decayed.  The dentist uses a special drill to remove all decay before filling the cavity with a different type of filling materials.  In a deep cavity, the dentist may place base material to protect the nerve. It is imperative to polish the fillings after completing the restorations to prolong the life of the fillings.  While the dentist can immediately polish the composite fillings, amalgam fillings require 24 hours before polishing.

The new, single-use Soft-Lex Spiral finishing and polishing wheels by 3M offer an easy way to put a natural-looking luster on restorations.


Types of tooth restoration:

1. Amalgam Filling


What is Amalgam filling? Amalgam fillings (silver fillings) have been the restorative of choice due to the affordable, simple application, durability, longevity, and bacteriostatic results for more than 150 years. Issues that may have triggered a current decrease in popularity can be ongoing concern about harmful health effects, appearance, and polluting the environment about mercury emissions in the course of preparation.

Advantages of using amalgam fillings:

1. Amalgam is sufficient for repairing molars at the back of the oral cavity where a chewing load is the greatest.
2. Amalgam is long lasting; extremely resistance against wear and it has higher durability in comparison with many other materials.
3. Amalgam is fairly low-cost compared to other substances.
4. Amalgam is simple to use with less application time compares to other materials
5. Bacteriostatic property of mercury in amalgam assists in slowing down the development of decay beneath the fillings.


Disadvantages of using amalgam fillings:

1. Dental amalgam is a combination alloy made of  50% mercury by weight, silver, tin, copper and some other metallic elements. Although dentists still use amalgam restorative material, queries have arisen concerning the safety associated with its mercury vapor continuously evolves from dental amalgam fillings. Department of Environmental Medicine at Slovak Medical University did a study related to mercury in a pregnant woman.  The study showed that if a pregnant woman exposed to the mercury, the fetus could be exposed to the mercury as well, resulted in possible subsequent neurodevelopmental disability in an infant.

Mercury gas can vaporize in the air resulted in the accumulation of mercury through inhaling. In 2009, the Food and Drug Administration (FDA) released a final regulation classifying dental amalgam from class 1(low risk) to class 2 (moderate risk).
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2. Due to its hot and cold conductivity, amalgam fillings occasionally may cause short-term sensitivity to hot or cold foods and drinks.

3. The contrast in color between amalgam fillings and tooth makes it undesirable.

4.The dentist needs to take out more tooth
structure during cavity preparation for amalgam filling than other types of fillings.

5. Amalgam fillings can cause galvanic shock.  Galvanic shock is an electrical current that can be felt when contact with different alloys such as a gold crown, stainless steel crown, stainless steel or silver utensils in the person's mouth. (Dissimilar metals in a conductive fluid create an electric current).

6. Amalgam filling by itself cannot withstand the stress when used in large cavity or cavity that involves cusps.

2. Composite Filling

There are two placement methods of composite filling:

Direct placement composite:  the dentist place dental composite directly onto the cavity that has been clear of decay in the dental office with the aid of curing light to harden the material in the patient's mouth. Dentists often use direct composite for:
  • Closing gaps between two or more teeth
  • Restoring chipped tooth 
  • Re-construct front teeth for aesthetic reason
  • Filling small cavities 
  • Sealing deep grooves and fissures to prevent the tooth from getting cavities in the future.

Indirect dental composite: the restorations are stronger and more durable than direct dental composite restorations.  The dentist fabricates restoration outside the patient's mouth before placing inside the prepared tooth. The dentists use indirect composite restorations for:
  • Onlays
  • Inlays and 
  • Veneers

Advantages of using composite fillings:
  1. Improved aesthetics due to a broad range of tooth color composites, allowing less contrast between the filling and the tooth.
  2. Requires conservative cavity preparation and preserve more of tooth structure
  3. Allow minor changes such as gaps, re-contour on front teeth for cosmetic purpose instantly in direct placement composite filling.

Disadvantages of using composite fillings:
  1. Some composite fillings shrink after placement create a marginal cavity
  2. Composite filling requires more placement time, thus more costly than amalgam
  3. The color stability of composite filling can vary significantly based on personal habits People who smoke, drink coffee or tea, have their color alter quicker than non-smokers
  4. Indirect composites filling require several dental office visits to complete
  5. Composite fillings are not as strong as porcelain or other metal restorations.
  6. Patients may experience some sensitivity after having the composite filling

3. All-Porcelain (Ceramic) Dental Materials

The advantage of using ceramic:
All-porcelain (ceramic) restorations are particularly appealing as their color and translucency is much better mimic natural tooth color than other fillings. Dentists prefer to use all-porcelain in veneer, inlay, onlay and crown restorations. The recent development of Zirconia,  a strong non-metal framework for porcelain, makes it possible to have a bridge made of porcelain.  With appropriate preparation can lead to much better esthetic and far better resistance against wear than composite filling.

Disadvantages of using ceramic:
All-porcelain restorations except Cerec involve at least two appointments and perhaps more to accomplish.

Since the porcelain restorations are susceptible to crack when put under stress, they demand tedious work and high skill to generate a long lasting porcelain filling. If rough spots remain on porcelain, the retained rough area can easily wear off opposing natural teeth or fillings.  Therefore; it is imperative to polish the porcelain after grinding.

4. Dental veneer(also known as porcelain veneer or porcelain laminate)

Dental Veneer is a custom made of a very thin shell of porcelain to cover the tooth that is discolored, worn, chipped, or misaligned to improve the appearance.

5. Inlay

The Inlay is a customized filling, an alternative to amalgam.  The Inlay is a durable and stable material that can strengthen a damaged tooth.

6. Onlay

Onlay is a customized filling that covers the entire chewing surface including one or more tooth cusps. Onlay is a conservative alternative restoration to a crown.  It preserves more tooth structure than the crown.

The procedure for inlays and onlays are similar, typically finish in 2 visits.  The material used in inlays and onlays are porcelain, gold, or composite resin.

7. Crown (Cap)

Crown is a restoration that covers the entire tooth to the gum line. The purpose of the crown is to protect the tooth from breaking after root canal treatment, replacing large fillings that have extensive decay, and use as an abutment in bridges. The dentist removes more tooth structure in preparation of crown than another type of restorations.


Before treatment
After treatment - 4 Porcelain veneers


Materials used in Crown, Inlay, and Onlay are:

1) Porcelain-fused-to-Metal
Porcelain fused to metal is constructed with sub-layer of metal with porcelain baked on the surface for cosmetic purpose.  The metal base can be non-precious metals or precious metal.


Advantage:
The metal uses in porcelain-fused-to-metal provides strength to a crown or bridge makes this restoration more durable and cosmetically acceptable.

Disadvantage:
More tooth structure must be removed to accommodate the restoration. Porcelain restorations can wear opposing natural teeth if the porcelain becomes rough. There may be some initial discomfort to hot and cold. Some patients may show an allergic reaction to some metals used in the restoration. Sometimes the porcelain can chip off.

2. Gold Alloys

Gold alloys contain gold, copper, and other metals.  The dentists use gold alloys in inlays, onlays, crowns and fixed bridges.

Advantage: Gold alloys are strong, durable filling, highly resistant to corrosion and tarnishing. Less tooth structure is removed to accommodate the restoration. Gold alloys are also gentle to opposing teeth.

Disadvantage: The contrast in color between gold alloys and tooth make gold alloys undesirable. Due to gold alloys conductivity property, sometimes gold alloys filling can cause short-term sensitivity to hot or cold may occur.  Gold alloys fillings can cause galvanic shock; an electrical current that can be felt when contact with different alloys such as amalgam fillings, stainless steel crown,  stainless steel
or silver utensils in the person's mouth. 

3. Cerec
Cerec is an all ceramic dental restorations producing durable, high-quality restorations. Cerec restoration is processed utilizing 3D CAD software along with a milling device generates the restoration from a ceramic block. The ceramic material expands and contracts in response to alterations in temperature changes in the oral cavity. Cerec wears approximately the same as enamel. The dentist can use it for several different restorations such as inlays, onlays, crown, and veneers.

Advantages:
1. More durable than other types of restoration
2. Requires one trip to finish the restoration
3. Has numerous color of the tooth-shaded to select
4. Does not need a temporary crown or temporary fillings in the process
5.The ceramic material utilized expands and contracts as your natural teeth do; less chance to have sensitive teeth following the restoration.

Disadvantages:
1. Fee is higher than other types of restoration
2. Less aesthetic in porcelain veneer
3. Greater tooth reduction to achieve the required thickness

4. Zirconia (Zirconium Oxide)
Zirconia is a nonmetallic restoration with high tensile strength, with translucency that is a very close resemblance to the natural teeth.  The dentists use Zirconia in the crown, a bridge for anterior and posterior teeth. Since it is fairly new to the dental field, more research is needed for a longevity of this material as a dental restoration.


 Zirconia crown                            Porcelain fused to metal