Clasp Denture

A clasp denture is a type of removable dental prosthesis based on a metal arc (clasp) that connects the left and right parts of the denture. The name comes from the German word “Bügel,” meaning “bracket” or “curved metal element.”

Clasp dentures cannot be called a new technology. They began to be used in dentistry at the beginning of the 20th century. At that time, specialists faced the challenge of creating more reliable removable dental prostheses that would be better fixed in the patient’s mouth. Clamp and bridge prostheses, which were widely used at the time, either had poor fixation or significant aesthetic drawbacks.

The idea of using clasps was a breakthrough in dentistry of the last century. The essence of the technology was to create a metal base that would ensure firm fixation of the prosthesis in the patient’s mouth. Gradually, the technology evolved from metal blanks to complex clasp systems.

The advent of clasp dentures was a breakthrough in 20th-century dentistry and provided a new level of comfort for patients who had lost some of their own teeth. However, today technologies have advanced far ahead, and clasp dental prostheses are used less and less in the modern world, as they have a number of significant disadvantages.

Clasp dentures cannot be placed on a completely edentulous jaw, as proper fixation is achieved through the patient’s remaining natural teeth — there must be at least 6. Depending on the method of attaching the prosthesis to the patient’s own teeth, the material, and design variations, the following types of clasp dental prostheses can be distinguished:

An obvious disadvantage of classic clasp dentures is the heavy weight of the construction. Vladimir Markelov attempted to address this by inventing a new type of such prosthetics in the 1970s.

Another variety of clasp dentures was developed by dentists in the 1920s–1930s. Its main feature is that the prosthesis is attached to the patient’s own teeth using telescopic connections. For this purpose, telescopic crowns are placed on the patient’s own teeth. Such a prosthesis consists of two parts: removable and non-removable.

Clasp dental prosthetics are impossible if the patient has no natural teeth. This type of removable prosthetics involves fixing the construction to the patient’s remaining natural teeth.

Depending on how exactly the clasp denture is fixed in the mouth, the following types of prostheses can be distinguished:

1. Clasp denture on clammers (hooks, clasps)

The attachment is a hook that grips two-thirds of the patient’s teeth. With this type of fixation, the prosthesis will be noticeable in the mouth.

2. Clasp denture on locks (clasp denture with lock fixation)

The first part of the attachment is placed on the patient’s own tooth, while the second is installed on the prosthesis — these can be either attachments or magnets. The snapping system most closely resembles the principle of clothing snap buttons.

3. Clasp denture on telescopic connections

Using this type of attachment requires grinding down the patient’s own tooth and installing a special crown resembling a cap. The second part of the attachment is inside the prosthesis, which literally fits over the crowns. The operating principle resembles an extending telescope.

Any type of prosthetics begins with a preparatory stage: treatment of teeth and gums, as well as sanitation. In some cases, removal of certain natural teeth is also required. However, clasp dental prostheses cannot be placed on a completely edentulous jaw. The required number of the patient’s natural teeth for clasp prosthetics is individual and depends on the clinical picture.

Prosthetics stages:

• preparation of teeth for crowns;
• creation of impressions of both jaws;
• preparation of temporary structures;
• prosthesis fitting;
• installation of the permanent structure and fixation.

The different structure of the upper and lower jaws, as well as their different masticatory (chewing) functions, determine differences in the modelling and attachment of prostheses.

Clasp dentures for the upper jaw may have cutouts that account for the anatomical structure of the palate. The thickness of the bridge in such prostheses reaches 1.2 mm, and the width can vary: from 4 to 10 mm. The prosthesis itself is fixed to the lateral incisors.

When modelling a prosthesis for the lower jaw, the anatomical structure of the tongue is taken into account. The prosthesis arc must be spaced from the mucosa at varying distances: 0.5 mm at the upper edge and 1 mm at the lower edge. The structure is attached to the lateral incisors.

1. Ischaemia and Bone Dystrophy

A clasp dental prosthesis exerts considerable pressure on the mucosal tissues, thereby provoking ischaemia — insufficient blood supply to the tissues. As a result of prolonged wearing of this type of prosthesis, the bones of the upper and lower jaws become thinner, making further prosthetics on implants impossible.

2. Limited Stability

A removable clasp denture, due to the anatomical features or a small number of the patient’s own teeth, may not be stable enough in the mouth. In addition, constant changes in the mucosa caused by ischaemia lead to a loss of tight fit of the prosthesis. Therefore, clasp dentures require constant rebasing.

3. Low Aesthetic Performance

Depending on the type of attachment, clasp dentures may be visible in the patient’s mouth not only when smiling, but even during conversation.

4. Discomfort and Speech Problems

A heavy, tightly fitting prosthesis causes discomfort for the patient and sometimes provokes speech defects. The patient requires a long adaptation period.

Regardless of the type and attachment method, a clasp denture, due to the listed disadvantages, is used less and less in dental practice. At our clinic, we use it only as a temporary measure.

Not only the disadvantages of the technology limit the use of clasp dentures — there are also direct medical contraindications:

• absence or insufficient number of the patient’s own teeth;
• mobility of own teeth;
• healing period of the mucosa after surgical intervention;
• diseases of teeth and mucosa that may be aggravated by wearing a clasp denture;
• pronounced atrophy of the alveolar ridge (jawbone).

The cost of a clasp denture can vary depending on the type of fixing element: the better and more complex the clasp design, the higher the price. The cost of a clasp dental prosthesis also increases if special crowns are needed to fix it.

Manufacturing a clasp denture requires the involvement of dental laboratory specialists, and the lion’s share of the final cost is the cast construction of the prosthesis base.

Thus, the price of clasp dentures will initially be higher than that of similar nylon or acrylic ones. Additionally, constant wearing of the prosthesis will require periodic rebasing, which will also affect the overall cost of clasp prosthetics.

Despite the fact that many clinics in Kyiv continue to use clasp dentures, our specialists do not recommend them from either a medical or economic standpoint.

The high final cost of such prosthetics, combined with significant medical and aesthetic disadvantages, makes the technology unacceptable. Created at the beginning of the 20th century, it was indeed a breakthrough in dentistry, but today prosthetics on implants exist. They allow creating non-removable prostheses that feel and look like the patient’s own teeth. If the patient has contraindications to implantation, we recommend using either acrylic or nylon prostheses — in terms of aesthetics and functionality, they are not inferior to clasp ones, and their cost is significantly lower.