At present, advances in science have advanced far. Correcting congenital or acquired defects of the dentition is now quite possible. Moreover, this can be done not only in children, but also in adults. Let's try to figure out what the clasp prostheses are, the stages of manufacturing such structures are also considered.
The appointment of clasp prostheses
This type of prosthesis is characterized by excellent strength, therefore, this design is used quite widely in dentistry:
- To eliminate tooth defects at the end of the dentition.
- For the treatment of pathologies of the lateral region.
- As removable dentures when replacing the teeth of the front row.
- For prosthetics of strongly loose teeth.
If a dentist recommends using arch prostheses for attachments for orthopedic treatment, the result will exceed all your expectations. Such designs are not only lightweight, but also look beautiful, practically do not differ from real teeth.
What is a clasp prosthesis?
If we consider clasp prostheses (the manufacturing steps will be described later), then they are an arch consisting of three main parts:
- Cast frame made of durable metal.
- Imitation gum plastic base.
- Artificial teeth that are fixed on the base.
To make it possible to install such a prosthesis, you must have at least a pair of your teeth, then the structure can be securely fixed.
Varieties of clasp prostheses
To consider the laboratory stages of manufacturing a clasp prosthesis, you need to know what varieties there are such designs. They are classified most often by the method of attachment in the oral cavity.
- Castle prosthesis on attachments. It is reliably fixed on the abutment teeth with the help of a crown and special micro-locks, which are completely invisible, because they are mounted directly into the prosthesis. This is ideal when you want to restore the dentition with the loss of several teeth. The steps of manufacturing a clasp prosthesis on attachments will be described below.
- Clammer. The prosthesis has a clasp mount and evenly distributes the load on the jaw. It is convenient to use, as it is easy to pull out and put into place.
- Telescopic. Dentures on telescopic crowns are the most expensive. The work of their manufacture requires high precision and care. The main elements of the prosthesis are a conical base and a dental crown with a cavity inside, ideally repeating the shape of the base. The basis on which the design is worn can be a turned tooth or an installed crown. This design provides a stable and reliable fit.
The steps for manufacturing a clasp prosthesis on clasps are much less labor intensive. They are easier to manufacture, and they are attached using small but strong hooks to existing teeth. But the disadvantage of this design is that when you smile or talk hooks can be noticeable. The dentures on attachments look much more aesthetic. These are small locks, but they firmly and reliably fix the prosthesis to the abutment teeth.
Recently, designs on telescopic dental crowns are gaining more and more popularity.
The stages of manufacturing a clasp prosthesis with lock fixation require more painstaking work, which will certainly affect their cost.
What materials are made of clasp prostheses?
All parts of prostheses are made using various materials. The frame may be metal or plastic. If plastic is used for the non-metallic part, then steel or alloys are used for the metal part, for example, chromium-cobalt or gold-platinum.
The steel structure has its drawback - an oxide film is formed at the site of soldering. And this indicates that there is a process of oxidation of solder in the oral cavity. For this reason, nowadays, steel parts are being used less and less, most often preference is given to solid cast structures.
Clasp prosthesis technology
Everyone should, of course, understand that it is possible to make such a complex structure only in the dental laboratory. To do this, use various methods:
- Casting of the structure with removal of the wax model from the workpiece. This technology involves removing the wax structure from the gypsum model and packing it into a refractory mass. The wax is removed and replaced with liquid metal.
- Casting a prosthesis on a refractory model. This method has some advantages over the first, since there is no metal shrinkage and the possibility of modifying the workpiece from wax when it is removed from the model and packaged in a refractory mass is excluded.
Let us consider in more detail the steps of manufacturing a clasp prosthesis on a refractory model. This process is very important to get a quality product.
Obtaining a design on a refractory model
The laboratory stages of making an arch prosthesis include an important point - taking casts. Of great importance for the casting of the prosthesis frame (so that everything is accurate to the millimeter) is the original gypsum model.
If the prosthesis is being prepared on a refractory model, then two casts of the workers and one additional one are made. In the manufacture of prostheses, four jaws are obtained immediately on two jaws, that is, two on each jaw. This is done so that one model can be used for consideration with subsequent copying, and the second is used to make the base with rollers, to determine occlusion, gypsum and the final manufacture of the prosthesis.
Of great importance for obtaining a high-quality prosthesis is the working model, so the specialist should constantly monitor the clinical and laboratory stages of the manufacture of clasp prostheses.
Models of the jaws should be as strong as possible so as not to undergo abrasion, therefore the parts that are particularly susceptible to pressure and load are made of super gypsum, metal, cement or amalgam.
If a defect of the working model is detected during operation, you will have to redo the cast.
Clinical stages of arch prosthesis manufacturing
In the process of manufacturing prostheses, there are several clinical stages:
- The first stage begins with an examination of the patient, a conversation with him, an accurate diagnosis, the choice of tactics for treating pathology. Also, the doctor will take casts for the preparation of diagnostic and auxiliary models.
- At the second clinical stage, jaw occlusion is determined, the diagnostic model is examined in a parallelometer, after which a drawing of the base of the future prosthesis is applied to it. It is important to prepare the abutment teeth in order to obtain the most accurate impression for the manufacture of the prosthesis.
- At the next stage, focusing on the diagnostic model, a boundary line and a picture of the prosthesis frame are applied using a parallelometer on the working model.
- At the fourth clinical stage, the metal frame is fitted in the oral cavity. It is necessary to pay attention that the frame does not have sharp edges and defects. The saddle base and the arc should not come into contact with the mucous membrane of the oral cavity. Clasps should be firmly in contact with the supporting teeth. The doctor carefully looks and determines whether there is a balance of the prosthesis, and, if necessary, eliminates supercontacts between the frame and antagonist teeth. Also at this stage is a selection of artificial teeth.
- The following is a design check. It is necessary to make sure that the clinical and laboratory stages of manufacturing the clasp prosthesis are met, and it meets all the requirements both on the model and in the patient's oral cavity.
- The last stage is reduced to the fact that a prosthesis is placed in the oral cavity, balance is checked. The doctor must give recommendations on the care of the structure.
All these stages of manufacturing a clasp prosthesis on locks or clasps are mandatory. This is the only way to get a solid and reliable design.
Laboratory manufacturing steps for prostheses
Clasp dentures also have laboratory stages, here are the activities that are carried out throughout them:
- At the first stage, the diagnostic model and the auxiliary are cast. Production of wax bases with occlusal rollers.
- The following is the manufacture of a working model.
- Prepare for duplication. For this, places that should not come into contact with the oral mucosa are isolated with a wax plate, and all voids are also filled with wax. Next, the model is fixed on a special cell for duplication. The heated mass is placed in it and cooled until it hardens. Then the model is removed and the refractory mass is poured into the obtained form. The prepared model is freed from the duplicate mass, dried and a drawing of the frame of the future prosthesis is applied to it. Next, the wax reproduction is modeled and replaced with a metal one.
- At the next stage, the working and auxiliary models are gypsum plated into the articulator and the artificial teeth are placed on the wax basis of the prosthesis.
- At the last stage, the wax basis is changed to a plastic one. Also, at the end, polishing and grinding of the prosthesis is mandatory.
On this, it can be considered that the clasp prostheses the manufacturing stages have all passed and are ready for installation.
Indications and contraindications
If it is not possible to build a bridge, the doctor advises the patient to clasp prostheses to correct the defect. Usually this cannot be avoided if there are no several teeth in a row and the supporting teeth are preserved on only one side. Clasp prostheses will also be necessary in the following cases:
- If there are no front teeth.
- There is a defect in the dentition.
- Missing lower teeth.
- The patient has a deep bite.
- Bruxism is also an indication for the use of such prostheses.
- Periodontal disease.
In addition to indications for their use, categorical prohibitions on the use of clasp prostheses can be distinguished:
- If you are allergic to a metal structure.
- There are no teeth to lean on.
- The bottom of the lower jaw has insufficient depth.
- The remaining teeth have a low crown.
- Blood sugar is too high.
- There are oncological diseases.
- Pathology of the cardiovascular system.
- Inflammatory processes in the oral cavity.
- Respiratory system diseases.
Advantages and disadvantages of clasp prostheses
Whatever designs are used for prosthetics, they all have their pros and cons. The same applies to clasp prostheses. Here are the benefits they have:
- Compact and lightweight.
- They are well fixed in the oral cavity.
- Correctly distributed during chewing pressure on the jaw.
- If the prosthesis is fixed on the upper jaw, then the whole palate is not affected, which does not lead to a violation of pronunciation and deformation of taste sensations.
- Great for treating periodontal disease.
- Ease of care.
- Long term use.
Clasp prostheses also have their disadvantages:
- Some patients may be allergic to the metal structure.
- You have to get used to them for a long time.
- To put them, you must have at least a pair of their teeth.
- Gradually, atrophy of the dental bone occurs.
- Their cost is much higher when compared with plate or bridges.
Of course, the advantages of this method of prosthetics are much greater, but before installing it is still necessary to weigh the pros and cons.
How to care for arch prostheses?
The sequence of clinical and laboratory stages of manufacturing arch prostheses is considered. If they are followed, the design will be solid and reliable. Despite the fact that arch prostheses are distinguished by their durability, some recommendations for care will still extend their service life:
- Clean the denture daily; you can use a regular toothbrush to do this.
- It is advisable to treat the oral cavity and prosthesis not only in the morning and evening, but also after each meal.
- It is recommended to purchase special disinfectant tablets for prosthesis care.
- If you have funds, you can buy an ultrasonic bath for care.
- It is advisable to visit a specialist once every six months, who will professionally clean the prosthesis and restore if necessary.
From these recommendations, it becomes clear that caring for clasp dentures is not at all complicated, but necessary so that they are not only comfortable, but also long-lasting.
With any pathologies in the structure of the dentition, only a competent specialist will be able to assess the severity of the defect and choose the most optimal prosthetics method.