Not everyone manages to keep their own teeth throughout their lives. Losing teeth is usually a matter of time. Some people lose their first molar by the age of 20, while others manage to maintain a full set of teeth until retirement. In any case, prosthetics sooner or later becomes relevant for the vast majority of patients.
Removable dentures are usually used in cases where quite a lot of teeth are lost, and the option of restoration with crowns or bridges on implants is not considered. Having a full set of teeth in your mouth is important for more than just aesthetics. Their deficiency affects the shape of the face, diction, and the ability to chew and digest food normally.
What are removable dentures?
The word “prosthesis” can be scary for some patients, especially if they are young. This word is associated with crutches, dentures and the decline of life. In fact, dentures, on the contrary, help restore the aesthetics and joy of comfortable eating. Modern technologies make it possible to make prostheses from high-quality materials. They are miniature, do not rub, do not fall out of the mouth when laughing or sneezing, and do not impair speech. In addition, artificial teeth are perfectly straight and beautiful, just like in the picture in the magazine.
The essence of the prosthesis is that artificial teeth are placed on a base made of high-strength material matching the color of the gums. The structures correctly distribute the chewing load, restore the proper functioning of the dental system and the beauty of the smile.
How is production carried out?
Manufacturing is carried out in a dental laboratory by a dental technician. First, the model of the prosthesis and materials are determined. As a rule, both metal wire and cast hooks are bent using special pliers, pliers and round nose pliers. Then the clasp is included in the base and the entire structure is tried on the patient; if necessary, the product is modified. During the manufacturing process, it is important to comply with the requirements for the manufacture of the shoulder and the implementation of the contact process. Thus, the shoulder should not overload the supporting tooth, but should adhere to the crown at the maximum number of points. The metal is well polished so that the hook does not injure the enamel and does not become a place where plaque accumulates. As for the process, it is bent with round nose pliers and notches are made for better connection with the base.
Indications
There are a number of indications for installing removable dentures:
- Pathological abrasion of teeth.
- Inability to install single crowns or bridges due to lack of sufficient teeth, jaw characteristics or financial aspects.
- Presence of end defect.
- The inability or unwillingness of the patient to restore the dentition with crowns on implants.
- Reluctance to prepare abutment teeth to install bridges.
- Periodontal diseases (chronic periodontitis, periodontal disease).
- The need to wait for other types of prosthetics (as a temporary option).
- The desire to restore teeth quickly and without significant financial investments.
Requirements for hook placement
Denture clasps must be selected in accordance with all of the following requirements:
- the fixation will be the same on all supporting teeth,
- rotation or overturning of the prosthesis is excluded,
- do not overestimate the bite in the presence of occlusal pads,
- do not lead to injury to the teeth (including those of the opposite or antagonistic teeth) when closing the jaws and chewing,
- do not greatly reduce the aesthetics of a smile: metal ones located in the “smile zone” are highly noticeable from the outside, while synthetic ones are less noticeable. But the latter quickly stretch and break more often,
- the supporting teeth do not have pathological mobility,
- crowns of correct anatomical shape and sufficient height (5 mm or more).
You also need to take into account the position of the boundary line - this is the line that divides the crown into supporting and retaining parts. This parameter is determined using a parallelometer device. So, for example, on the lower teeth, the upper part of the clasp (occlusal pad and top of the shoulder) is located above the boundary line, and the lower part of the shoulder falls below the line. On the upper jaw, everything is, accordingly, the opposite.
Preparing for installation
Before using removable prosthetics, as with any type of prosthetics, some preparation is required. It includes:
- Sanitation of the oral cavity. The stage includes the treatment of caries, removal of mobile, damaged and untreatable teeth. Inflammatory processes, if any, are also treated.
- Taking impressions of both jaws. In any case, there are two impressions, so that when making a prosthesis, the correct bite can be maintained, and the prosthesis does not interfere with the patient’s ability to close his jaws normally.
- Making a plaster model. Based on this model, the structure is subsequently manufactured.
- Fitting and correction stage. Fitting is an important part of the process to make wearing as comfortable as possible and avoid damage to soft tissue or supporting teeth.
Types of clasps
Depending on the material, clasps for fixing dentures are:
- Metal.
- Plastic or nylon.
- Metal-plastic.
Metal hooks have the lowest aesthetics. They are visible when talking and smiling. Nylon ones are made in the color of the gums, have the required transparency, due to which they are practically invisible to others. Their disadvantage is the incorrect distribution of the load during chewing. The material is soft and cannot provide the required rigidity (unlike less aesthetically pleasing metal).
Depending on the type of fastening, clasps are of dental, gingival and mixed types. According to the manufacturing method - bent, cast and combined.
Briefly about each of them
- Acrylic dentures. These are the most common and inexpensive prostheses. They are very light, do not require tooth preparation; hooks are used for fastening, covering the patient’s own teeth. The plastic from which they are made can cause allergies only in severe cases, and is used for the vast majority of cases.
- Acrylic-free dentures. From the name it is clear that acrylic is not used in these designs. They better distribute the chewing load, while the material is free of additives that can cause irritation to soft tissues. Acrylic-free dentures are durable and fit well to the gums. If there are teeth, hooks are used for fastening; if not, a system similar to a suction cup is used.
- Nylon systems. This is a traditional option for restoring several teeth, that is, small areas in a row, rather than the entire jaw. Constructions are not used for edentulous patients, since due to their softness they cannot evenly distribute the chewing load, which leads to rapid resorption of bone tissue. In terms of cost, these comfortable soft prostheses are quite expensive in comparison with those described above.
- Clasp dentures. Durable structures with a reduced contact area on the palate and gums. This is achieved due to the thin body. The base is a metal plate, which can be covered with a layer of plastic in the color of the gums. Features are: uniform load distribution, maximum preservation of bone tissue, miniature size. Fastening is carried out using hooks and locks. Due to the presence of metal, the prosthesis can occasionally cause irritation of the mucous membrane.
- Sandwich dentures. These are new generation systems that are located in the mouth without affecting the upper or lower palate. To attach them, it is sufficient for the patient to have two supporting teeth.
- Quadrotti. Nylon-based prostheses, manufactured using the latest Italian techniques. This is a variation of the sandwich system with some special features. The dentures are durable, comfortable, and do not require long getting used to.
Types of dentures on hooks
Hooks help fix different types of prostheses:
- Acrylic dentures. This is the cheapest and most common option. The design consists of an acrylic base with artificial crowns attached to it. Most often, “teeth” are also made of acrylic; crowns made of ceramics are less common. The prosthesis is adjacent to the gum and is additionally secured with hooks. The shade of the base is selected to match the natural color of the patient’s gums. The disadvantage of acrylic is that it does not always look natural due to its opacity. The prosthesis is durable, light and cheap, which is a definite advantage. Disadvantages include poor aesthetics and the need to get used to a rigid and fairly voluminous structure.
- Clasp dentures. More expensive and, undoubtedly, ahead of other prosthetic models in terms of comfort, strength and other indicators. The principle of the structure is the same as that of acrylic ones, but instead of a massive acrylic base, clasp structures have a thin metal plate (on the sides the dentures also have plastic parts in the color of the gums). They are durable and take up much less space in the mouth. The main condition for their installation is the patient’s own teeth on both sides of the jaw. The clasp denture correctly distributes the load when chewing, which allows you to slow down the process of resorption of bone tissue where there are no teeth.
- Nylon prostheses. Partial designs made of nylon with hooks are much less noticeable in the mouth due to the fact that their clasps are made of the same material as the base. Nylon has the desired transparency, making it almost invisible when talking or smiling. Prostheses of this type are comfortable due to their flexibility and softness; they do not rub and do not require a long period of getting used to. There are also disadvantages. The main one is the failure of nylon hooks. They are soft and cannot provide proper load distribution.
Which removable denture is better to install?
The choice of orthopedic design depends on the clinical picture, preferences and financial capabilities of the patient. The main condition is a correctly manufactured prosthesis, which is easy to use and receives sufficient care from the patient. It is also necessary to think about the prospects: if your plans for the future include dental implantation, then it is better to give preference to a prosthesis with a rigid base, which will more correctly distribute the load on the bone tissue, preventing its atrophy.
The average cost of installing removable dentures in Moscow is from 9,000 rubles to 60,000 rubles.
Service life of dentures with hooks
The lifespan of a clasp denture is about five years. Nylon can be used less as it is more flexible and susceptible to deformation. Replacement is required because the fixation strength decreases over time. This occurs due to the gradual resorption of bone tissue and subsequent disruption of the fit of the structure. Due to the fact that clasp dentures correctly distribute the load, the atrophy process is slower. Nylon, due to its softness, allows the process to go faster.
An alternative to clasp fixation is to attach it to locking attachments. Fastening elements are placed on crowns fixed to abutment teeth. Locks allow you to firmly fix the structure.
Author:
Mayorov Andrey Mikhailovich
Specialization:
orthopedic dentistry, dental prosthetics, implant installation
Comparison of classic and removable dentures on implants
Classic removable dentures
- the lower jaw is strongly pushed forward or backward, shifted to the right or left,
- relative comfort - dentures can fall out of the mouth,
- hooks are used for fastening, which can be visible on the teeth,
- quite massive dimensions when attaching the prosthesis to the gums,
- dentures put pressure on the gums, causing pain and inflammation of the mucous membranes,
- It takes quite a while to get used to dentures, they change diction,
- dentures must be regularly repositioned due to subsidence of the bone tissue underneath them,
- The service life of dentures is quite limited
Removable dentures on implants
- maximum comfort – dentures are securely fixed in the oral cavity,
- there are no hooks in the designs - the fastening elements are located inside the prosthesis, under the gum,
- dentures are smaller in size, which improves wearing comfort,
- dentures practically do not rest on the gums, therefore they do not injure them at all,
- getting used to dentures is easier due to their smaller size and better fixation,
- prostheses require adjustment only in the first months, while the implants take root and bone tissue is restored,
- Dentures on implants will last 2 times longer due to their ability to withstand heavy loads.
Disadvantages of removable dentures on implants
One of the main disadvantages of removable dentures on implants is the presence of artificial gums made of plastic. On the one hand, it increases the size of the structure, which makes it less convenient. On the other hand, in many situations you simply cannot do without it - it covers the uneven contour and problematic mucous membranes, which change due to inflammatory processes and bone tissue atrophy.
Common clasp designs
- Ney's system: there are 5 types of clasps - Acker, Roach, combined (from Acker and Roach designs), single-arm reverse action, single-arm ring. This system was developed in 1949 with the participation of dentists and engineers. It includes both already known fastenings (modified) and new ones,
- developed by Acker: a supporting-retaining element with a rigid connection, consisting of 2 arms, an occlusal pad and a body. One of the oldest and most famous varieties, which first appeared in 1926,
- Roach: a support-retaining device with an occlusal pad and a spring (elastic) connection, which is easy to distinguish from others - its two arms look like the letter “T”. Because of this similarity, the hook is called “split”. Made from cobalt-chromium and gold-platinum alloys,
- Bonneville: Also known as the “six-arm” because it consists of 4 arms and 2 occlusal pads. Fixes 2 teeth at once,
- Jackson: includes 2 branches and 2 bodies, made of wire,
- Adams: one of the most versatile and effective types, suitable for both free-standing teeth and those included in segments,
- arrow-shaped Schwartz clasp: consists of 1 or 2 links, can also be multi-link. It is made of elastic wire and fits well into the interdental spaces.
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