most often used and still the most economical restorations are fillings.
amalgam filling is metal, composed of silver particles mixed with mercury. There has been big controversy as to the safety
in the use of these fillings. ADA (American Dental Association) still states that it is safe to use. Because
we did not do our own study, we would not state our opinion on the safety of this product and let each patient decide for
themselves. Putting the safety factor aside, there are still many disadvantages of the amalgam fillings. These amalgam fillings
have a substantially higher degree of thermo-expansion than that of the tooth. What that means is, drinking hot coffee or
cold soda would make tooth and the filling expand differently, which will eventually lead to a gap between the tooth and the
filling( pot-hole effect). This gap is a pathway for food and bacteria to invade the tooth and cause it to decay around the
filling (secondary decay). It also means that if the filling is large, its expansion could cause a lot of stress on the remaining
walls of the tooth, and in many cases the walls of the tooth can break off. Another
big disadvantage of amalgams is its color: it not only looks grey, and gets darker with age, it also shines through the thin
walls of the tooth. Sometimes, amalgams cause dark spots on the tissues of the mouth called amalgam tattoos.
|Tooth restored with composit filling
|Tooth prepared for composit filling
|Tooth prepared to receive composit filling
An alternative to amalgam fillings
are composite fillings which is a tooth colored plastic mixture filled with glass (silicon dioxide). Introduced in the 1960s,
dental composites were limited to the front teeth because they lacked the strength needed to withstand the pressure and wear
generated by the back teeth. Since then, composites have been significantly improved and can be successfully placed in the
back teeth as well. Following preparation, the dentist will chemically treat the tooth with a special bonding agent, allowing
it to penetrate inside tooth structure to give a stronger bond to the filling, then he places the composite in layers, using
a special light to harden each layer. The final step is to trim off the excess
material, to adjust the bite and to give is a thorough polish that prevents staining and early wear. Because a composite is
placed incrementally and the process is more laborious than silver fillings, it takes the dentist about 10-20 minutes longer
to place depending on the size and location of the cavity. Esthetics is the main advantage, since dentists can blend shades
to create a color nearly identical to that of the actual tooth. Composites bond to the tooth to support the remaining tooth
structure, which helps to prevent breakage and insulate the tooth from excessive temperature changes.
What are the disadvantages?
Along with the higher cost and
the extra placement time, the patient can experience postoperative sensitivity. Composite materials are porous which means
that certain foods and beverages that we consume along with smoking can stain the restoration. Another drawback: composites
tend to wear out sooner than silver fillings in larger cavities, although they hold up as well in small cavities.