The loss of back teeth, or posterior edentulism, is a common issue that significantly affects oral function and overall dental health. Molars and premolars are the primary teeth responsible for grinding and chewing food, which is a process known as mastication. When these teeth are missing, the balance of forces in the mouth is disrupted, making it difficult to process many foods properly. Fortunately, modern dentistry offers several viable restorative options to replace these missing teeth and restore full chewing capability.
Why Replacement is Essential
Leaving the space from a missing back tooth empty can trigger negative biological consequences throughout the mouth. Without the support of the adjacent tooth, neighboring teeth will begin to drift or tilt into the open space, disrupting the alignment of the entire dental arch.
The tooth in the opposite jaw that no longer has an opposing partner will begin to move out of its socket in a process called super-eruption or extrusion. This vertical migration leads to an uneven bite and can complicate replacing the missing tooth later on.
The jawbone beneath the empty space lacks the stimulation normally provided by the tooth root, leading to bone resorption. The jawbone can shrink in both height and width, which may affect the shape of the face over time and limit future replacement options. This loss of bone and the shifting of teeth can change how the jaws meet, potentially leading to temporomandibular joint disorder (TMD), characterized by jaw pain or clicking sounds.
Permanent Replacement Options
Dental implants are widely considered the gold standard because they replace the entire tooth, including the root structure. An implant involves surgically placing a titanium post into the jawbone, which then fuses with the bone in a process called osseointegration.
The titanium post acts as an artificial root, which is then topped with a custom-made crown that functions like a natural tooth. A major benefit of this method is that the implant stimulates the jawbone, helping to prevent the bone loss that occurs when a tooth is removed. Implants are also independent of surrounding teeth, meaning healthy neighboring teeth are not altered or damaged.
Another fixed solution is the traditional dental bridge, which “bridges” the gap using artificial teeth called pontics. This restoration is cemented onto the natural teeth adjacent to the gap, which must be prepared and covered with crowns to serve as anchors. Bridges can be completed in a shorter timeframe than implants and do not require surgery.
The main drawback of a traditional bridge is that the supporting teeth must be ground down, which can compromise their long-term health. Unlike implants, a bridge does not provide stimulation to the jawbone beneath the missing tooth. Bone loss can still occur in the area underneath the bridge.
Removable Replacement Options
Removable partial dentures (RPDs) offer a less invasive and often more cost-effective alternative to fixed restorations. These appliances use clasps or precision attachments to secure replacement teeth to the patient’s remaining natural teeth. RPDs can consist of a gum-colored acrylic base or a more durable cast metal framework.
The metal framework RPDs, often made from cobalt-chromium or titanium, are generally thinner, more lightweight, and more durable than all-acrylic versions. These types offer better stability for chewing and tend to last longer. However, RPDs must be removed daily for cleaning and typically offer less chewing function than fixed options.
Temporary restorations, sometimes called “flippers,” are light acrylic partials used for short-term aesthetic or transitional purposes. While inexpensive and quickly made, they are not recommended for long-term use in the posterior region due to their weaker material and lack of stability for heavy chewing forces.
Factors Influencing Treatment Choice
The decision between an implant, a fixed bridge, or a removable partial denture depends on several patient-specific factors. Cost is a significant consideration, as implants typically represent the highest upfront investment, followed by bridges, with RPDs being the least expensive initial option. However, because implants can last a lifetime, their long-term value may be greater compared to bridges, which generally need replacement every 5 to 15 years.
The patient’s overall health and the condition of the jawbone are also important, particularly for dental implants. Successful implant placement requires sufficient bone density to support the titanium post. If significant bone loss has already occurred, a bone grafting procedure may be necessary before an implant can be placed, which adds to the timeline and cost.
The condition of the teeth adjacent to the gap can dictate the preference for a bridge over an implant. If the neighboring teeth already require crowns due to decay or large fillings, a bridge may be a practical solution since the necessary preparation will address their existing issues. Conversely, if the adjacent teeth are perfectly healthy, an implant is preferred as it preserves the natural tooth structure.