Why Bonded Restoration
In the past when patients needed fillings placed in their back (chewing) teeth, dentists had only one choice of materials for these fillings: silver amalgam. Amalgam fillings are made of silver and other metals that are mixed with mercury just prior to placement in the patient’s tooth. Silver amalgam fillings have serviced patients and dentistry quite well for decades. The material does have its limitations and potential problems:
Recent studies suggest that large silver amalgam fillings can contribute to the fracture of teeth. Silver fillings contain mercury. Mercury is used in thermometers because it expands and contracts with changes in temperature. The mercury in silver amalgam fillings does the same thing. This expansion and contraction of the silver filling causes stress in the tooth structure that surrounds the filling. This stress can sometimes cause the tooth structure to fracture or break away from the tooth.
Over the years, the silver amalgam filling breaks down at the margin where the filling meets the tooth. This break down of the metal causes the “seal” to be broken which allows decay causing bacteria to enter the area.
Silver amalgam fillings do not bond to tooth structure. They are held into place by undercuts that the dentist has to make when preparing the tooth (drilling) for the restoration. This means that tooth structure other than the decayed area has to be removed. Also, when a filling is very large, the dentist may have to place reinforcement pins into the tooth in order for the filling to be held in place.
Silver amalgam fillings are unattractive, darken with age and cause discoloration of the teeth they are placed in.
What are the Alternatives to Silver Amalgam Fillings?
With recent advances in dental material technology and bonding techniques, dentists have alternatives to placing silver amalgam fillings. Two of these alternatives are Composite Bonding and Composite Inlays or Onlays.
COMPOSITE BONDING (Tooth Colored Fillings)
What are the Advantages of Composite Tooth Colored Bonded Fillings?
- Tooth colored bonded fillings are sealed to the tooth structure which prevents decay causing bacteria from infiltrating into the inner part of the tooth.
- Composite bonding does not expand and contract with temperature changes which could aid in preventing tooth fractures.
- Many bonded fillings release fluoride in the tooth which prevents recurrent decay.
- Tooth colored fillings look great!
How is the Procedure Different from Having Silver Amalgam Fillings?
In many cases, the procedure is very similar to having silver amalgam fillings. The tooth or area is numbed with a strong anesthetic solution. The decay or old filling is removed and the tooth is prepared to accept the restoration. Generally, a smaller amount of tooth structure is removed when preparing for a tooth colored filling. The tooth is then “etched” with a mild acidic solution. This roughens the enamel surface and allows the bonding material to adhere. A shade of composite material is chosen that matches your natural tooth and is placed into the tooth. The dentist then shines a bright light on the area to harden the material. The filling is then trimmed to adjust to your bite and to achieve proper contour and shape.
How Long Will Tooth Colored Fillings Last?
How long any filling lasts depends on many factors. First, smaller fillings that are surrounded by natural tooth structure will last much longer than large fillings that are not surrounded by natural tooth structure. Secondly, how much biting pressure is exerted by opposing teeth is also important. Home care, frequency of check up visits and quality of diet are also factors that affect the longevity of fillings. Tooth colored fillings can last years before needing repair or replacement.
What are Composite Inlays or Composite Onlays?
Composite inlays and onlays are tooth colored fillings that are custom fabricated in a dental lab. They are placed in teeth as replacements for silver amalgam fillings. Composite inlays and onlays are bonded onto the tooth.
What Advantages Do They Have Over Composite Bonded Fillings?
If the silver restoration is very large, a composite inlay or onlay may be recommended over composite fillings because they are stronger. Rather than merely filling your tooth, composite inlays or onlays forms a lasting bond that reinforces your tooth from every angle. They are custom made in a dental laboratory. For this reason, composite inlays or onlays are very esthetic restorations that match the look of natural teeth. The cosmetic results frequently exceed patients’ expectations. Composite inlays or onlays are wear resistant and wear better than many other restorative materials.
What Advantages Do Composite Inlays or Onlays Have Over Crowns?
When a tooth is prepared for a crown, a good deal of tooth structure has to be removed by the dentist in order to make room or space for the crown. When a tooth is prepared for a composite inlay or onlay, only the old filling is removed and a very small amount of additional tooth structure is sacrificed. More of your natural tooth structure remains when inlays or onlays are chosen.
How are Composite Inlays or Onlays Done?
This is a two visit procedure. On the first visit, the area is made numb with a strong anesthetic solution and the old silver filling and decay (if present) is removed. The tooth is prepared for the inlay or onlay and an impression of the area is taken. A temporary filling is placed in the tooth. On the second visit, the temporary filling is removed and the composite onlay or inlay is fitted to the tooth prior to permanent placement. When it meets your dentist’s satisfaction, it is then bonded into place.
The materials that we use today are much more esthetic and even stronger and possibly longer lasting. They look, feel, and function like natural teeth. Our concern is your comfort and confidence. Our goal is to help preserve your smile for a lifetime.