Porcelain vs. Plastic Denture Teeth

By Brian J. Gray, DDS, MAGD, FICOI

In the past, artificial porcelain teeth were generally preferred over plastic teeth due to their greater durability and esthetics. However, in recent years, new generation biomaterials have resulted in the development of very wear-resistant plastic teeth. Clinically, the esthetics of plastic and porcelain denture teeth is nearly comparable, with good quality porcelain teeth still being the standard for esthetics. However, the majority of dentures today probably are fabricated with plastic teeth. For all practical purposes, the cost of porcelain and plastic teeth 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.

Some Selection Factors

• Balanced bite and force transmission: 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 porcelain teeth are more wear-resistant, their occlusion will not become significantly self-altered by wear, as will plastic teeth. However, when alveolar bone changes cause an unbalanced occlusion, the resulting biting forces from porcelain teeth 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, plastic teeth would probably be a preferred choice over porcelain teeth.

• Bone loss: 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 porcelain teeth.
• Noise: If porcelain teeth 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).

Which Type of Tooth Is Best?

• If a person has been successfully wearing dentures with porcelain teeth, then they should probably continue with porcelain teeth. These teeth will not wear as fast as plastic teeth, and the relationship between upper and lower jaws will tend to stay normal for a longer time than with plastic teeth.
• 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 plastic teeth should be selected because porcelain teeth, 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.

Tooth Strength

Because porcelain teeth are extremely hard in comparison to plastic teeth, they tend to chip and crack more easily. For this reason, when dentures having porcelain teeth 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.