In the past, false teeth made with porcelain were generally preferred over false teeth made from plastic due to their greater durability and esthetics. However, in recent years, new generation biomaterials have resulted in the development of very wear-resistant false teeth made from plastic.
Clinically, the esthetics of plastic and porcelain denture teeth is nearly comparable, with good quality false teeth made from porcelain still being the standard for esthetics. However, the majority of dentures today probably are fabricated with false teeth made from plastic. For all practical purposes, the cost of porcelain and false teeth made from plastic are about the same.
While porcelain and plastic teeth are competitive with regards to durability, and to a lesser extent, esthetics and wear, there are other factors that may favor the selection of one type of tooth over another.
Denture bite (called occlusion) changes due to the constantly changing jawbone (called alveolar bone) upon which a denture rests, and, to varying degrees, uneven tooth wear resulting from use. Unless a denture is evaluated and its occlusion adjusted to a uniform and even contact (called balanced bite or balanced occlusion) at regular intervals, denture occlusion will become unbalanced.
Since false teeth made from porcelain are more wear-resistant, their occlusion will not become significantly self-altered by wear, as will false teeth made from plastic. However, when alveolar bone changes cause an unbalanced occlusion, the resulting biting forces from false teeth made from porcelain will be unevenly transmitted to underlying supporting alveolar bone. Frequent tissue refitting of the denture usually eliminates or lessens this problem.
Porcelain denture teeth tend to transmit the impact of biting forces to the alveolar ridge with greater intensity than that transmitted by plastic teeth in an unbalanced tooth contact situation. Some practitioners are of the opinion that this greater force, especially when uneven as in an unbalanced occlusion, may be damaging to the alveolar ridges and could result in accelerated bone loss.
Therefore, unless denture occlusion is checked and balanced on a regular basis, false teeth made from plastic would probably be a preferred choice over false teeth made from porcelain.
If a person has lost a great deal of supporting alveolar bone and their gum tissue is not of a sturdy type, then plastic denture teeth might be a better choice. These teeth are more forgiving of excessive forces developing from habits such as clenching, grinding, and tapping or "clacking" of teeth, which seems to be more prevalent among older individuals. Plastic teeth do not transmit forces to underlying bone as intensely as false teeth made from porcelain.
If false teeth made from porcelain are vigorously used or sometimes habitually tapped together, a "clacking" sound can be heard. Plastic teeth will muffle this sound and be quiet during normal function or habit jaw motions (called parafunction).
If a person has been successfully wearing dentures with false teeth made from porcelain, then they should probably continue with false teeth made from porcelain. These teeth will not wear as fast as false teeth made from plastic, and the relationship between upper and lower jaws will tend to stay normal for a longer time than with false teeth made from plastic.
Regardless of which type of tooth is selected, the success of the selection is strongly based upon regularly checking dentures for proper balanced occlusion and fit on regular intervals.
If a denture is going to be worn against opposing natural teeth, then false teeth made from plastic should be selected because false teeth made from porcelain, being harder, could excessively wear natural teeth away.
After a thorough examination and frank discussion of what a person wants from wearing a denture, a licensed dentist can effectively discuss which type of tooth would best meet a particular individual's unique needs and desires.
Because false teeth made from porcelain are extremely hard in comparison to false teeth made from plastic, they tend to chip and crack more easily. For this reason, when dentures having false teeth made from porcelain are brushed and cleaned, they are generally handled over a sink filled with water or over a towel. Should the denture accidentally fall, the water or towel would help break the fall and hopefully reduce tooth breakage.
by Joseph J. Massad, D.D.S.