Preparation (“grinding”) of teeth is one of the main stages of any type of orthopedic treatment with the exception of prosthetics on implants. It involves grinding down teeth to create space for future orthopedic structures. This stage is considered the most unpleasant stage of the entire treatment. Previously, this was due to imperfect technology and lack of adequate pain relief. Today, thanks to modern technology, discomfort during tooth preparation is already a rarity.
Modern technologies include high-speed tips and diamond burs, which allow you to quickly “sharpen” the necessary teeth. These are local anesthetics that completely relieve pain during tooth preparation. These are temporary crowns that allow you to protect your teeth after preparation and continue to chew food and smile freely.
Why do you need to prepare your teeth?
Why can’t you immediately make a crown or inlay for a damaged tooth? What does “grinding” teeth do? The image below will help answer this question:
(image: tooth before preparation, tooth after preparation, tooth covered with a crown)
The future crown must fit perfectly to the surface of the tooth. Only this is a guarantee of its reliable fixation and prevention of secondary caries. As you can see, the natural anatomical shape of the tooth crown does not allow you to immediately make an artificial crown for the tooth. This is due to the fact that the side walls of the tooth are not flat, but convex. During preparation, they are ground down and the tooth acquires a conical shape, allowing a crown to be placed on it without any gaps. In addition, the future crown has a certain thickness, so it is important to prepare free space for it so that after fixation it does not protrude anywhere and does not interfere with closing the mouth and lateral movements of the lower jaw.
During tooth preparation, the dentist also removes altered carious tissues, if any, and old fillings from its surface. This prevents the appearance of secondary caries under the crown. In case of significant destruction of the coronal part of the tooth or its complete absence, the tooth stump is restored using intra-root inlays or pins.
Types of ledges
A ledge is the part of hard tissue remaining after preparation on which the future prosthetic structure is planned to be secured. There are three varieties of it:
- Rounded . Used under metal-ceramic prosthesis. Allows you to preserve the maximum amount of hard tissue. Thickness varies from 0.8 to 1.3 mm.
- Knife-shaped. Designed for solid metal crowns. Ideal for turning inclined pieces. The width ranges from 0.3 to 0.5 mm.
- Brachial. It is the most reliable and durable when securing orthopedic products, but is uneconomical in terms of removing a large volume of tissue. The width is about 2 mm. Requires removal of the nerve from the tooth (depulpation).
If you do not create a ledge before prosthetics, the quality of the fit of the prosthesis will decrease significantly. This circumstance complicates oral care and increases the likelihood of developing recurrent caries.
Is it painful to prepare teeth?
No.
- If pulpless teeth are prepared, then the tooth, by definition, cannot respond to this. It lacks sensitive nerve endings that perceive external stimuli.
- Vital teeth (alive, not pulpless) are always prepared under local anesthesia. Modern medications provide an adequate level of pain relief, and the person does not feel discomfort.
- Often during the preparation process it is necessary to place a special thread around the tooth, which allows the dentist to carry out preparation in the cervical area. It moves the gum back and prevents injury. To ensure that thread placement does not cause discomfort, local anesthesia is used.
In all of the above cases, tooth preparation will not cause pain either from the gums or from the teeth.
Some nuances
Each orthopedic product has its own rules and requirements for its installation. Depending on the type of prosthesis, the preparation stages differ.
Under the crown
When it is planned to install a solid cast structure, grinding begins from the side surfaces to avoid damage to adjacent units.
For metal-ceramic crowns, about 2 mm of enamel is removed from the sides of the tooth, and a ledge is created that matches the type of product selected. To ensure a tight fit, the enamel is not polished, but is left slightly rough.
When a porcelain crown is installed, the tooth is ground down to a cylinder or cone shape, however, the ledge must be 0.1 cm into the gum.
If the prosthesis is made of zirconium, the ledge is formed with clear boundaries of a round or shoulder-shaped shape.
In the video, watch the process of preparation with a ledge for installing a crown.
Under veneer
Since a veneer is an overlay on the outer side of a tooth, when turning, special attention is given to the front surface
.
The sides are processed in two ways:
- leaving contact between teeth;
- with output to the inner side of the ledge boundaries.
Another point is that if the veneer is made of ceramic, the preparation is carried out to the gum. If a composite is used, no preparation is carried out (the layer is left slightly rough to improve adhesion to the material).
For tab
An inlay is a partial prosthesis, so when grinding it is important to make the side walls parallel and maintain the dimensions of the corners. Compliance with these conditions will ensure tight insertion and reliable fixation of the insert in the cavity.
Important! To eliminate the likelihood of developing repeated caries, the cavity of the tooth being restored is slightly expanded.
Under a prosthesis
In this case, preparation is carried out with the aim of shortening the prosthetic elements. During treatment, all thin and sharp walls, dentin and enamel protrusions are removed. The best option is to give the cavity an oval shape.
Under special circumstances, the pulp is first removed.
When splinting
Splinting is a procedure that secures units in a row and prevents their further loosening. The procedure involves minimal grinding of the enamel.
Typically, dentists adhere to the technique used when installing metal-ceramic crowns.
How is tooth preparation performed?
Teeth preparation is carried out under local anesthesia, if we are talking about vital teeth (“living”, not pulpless). Using a special tip and burs of various shapes, the dentist creates a space that the dental technician will later use to make restorations (crowns, inlays). The rotation speed of the burs reaches 400,000 rpm. To prevent overheating of the prepared tooth, water and air cooling are used.
Prepared teeth must be protected with temporary crowns. The next step after preparing the teeth is taking impressions. You will find more detailed information about prints on the next page.
Answers to frequently asked questions
Since the term “dissection” is not widely used among patients, many of them are keenly interested in information regarding this procedure itself.
- What layer of fabric is removed? The amount of grinding depends on the type of structure being installed, the characteristics of the tooth surface and its original volume.
Usually no more than 2 mm of hard tissue is removed. But this volume depends on the type of prosthesis being installed. So, before placing the inlays, only 0.5 mm is ground on each side. - How much does it hurt ? Modern technologies allow the procedure to be performed absolutely painlessly. When processing “live” units, local anesthesia is administered.
- How long does the process take? The duration of the process depends on the technique chosen by the doctor. On average, processing takes from half an hour to 2 hours.
- Is it possible to do prosthetics without preparation? Unfortunately, it is impossible to fix the product in a high-quality manner without grinding. If this manipulation is skipped, a person may face a number of negative consequences in the future.
- Can this be done for children ? This procedure has no restrictions regarding the patient's age. Children usually undergo chemical preparation.
- Why do my teeth and gums hurt, and what can be done ?
The cause of pain may be too deep grinding, as a result of which the dentist left a very thin tissue layer, and the nerves in the pulp react quite painfully when eating hot/cold foods. Another common cause of pain after turning is inflammation. In any case, the manifestation of this symptom is a reason to immediately seek medical help.
“Prosthetics without grinding teeth”
Such headlines can often be found in advertising headlines. Why do you need to prepare a tooth and is it possible to do without it? I’ll answer right away that it is impossible to make a crown on a tooth without grinding it down.
If you make a crown for a tooth without preparation, it will inevitably interfere with closing the mouth, since there will simply be no room for it in the dentition. Remember how you felt after getting a filling, when the dentist asked at the end of treatment: “is the filling bothering you?” The filling often really gets in the way and the therapist grinds it down, asking you to knock your teeth so that the excess contacts are imprinted using carbon paper. In this case, we are talking about fractions of a millimeter by which the filling overestimates! Imagine what will happen if you put a crown on an ordinary tooth, the thickness of which is 2-3 millimeters? In addition, a tooth covered with such a crown would look extremely unnatural. Moreover, due to the convex anatomical shape of the tooth walls (the presence of the so-called equator), such a crown would simply be impossible to put on the tooth. But still, what do those who place such advertisements mean?
Firstly, this may be called “adhesive bridges” (synonymous with “Maryland bridges”). The point is that if one tooth is missing, grooves are made in two adjacent teeth. They are needed to secure the fiberglass tape, which is pulled from one tooth to another. This tape is then used as a beam on which an artificial tooth is modeled from a composite material. The result is aesthetic work if the therapist has good manual skills. In general, this design cannot be called successful. Secondary caries may appear in the areas of the grooves; such bridges cannot withstand the chewing load and break. It is also impossible to correctly restore occlusal contacts without the help of a laboratory. In addition, to make such a restoration, the teeth are still prepared when grooves are made in them. At the moment, the best way to restore one missing tooth, if the adjacent teeth are healthy, is implantation, and not dubious structures based on “carbon fibers”, etc.
The second technology that restores teeth without grinding them down is lumineers . “Lumineer” is a patented name for a ceramic veneer that is bonded to a tooth without prior preparation. Lumineers are made only in the USA. This technology is currently not certified in Russia. In addition, it has limited indications for use and far from always it actually improves the appearance of teeth. In Russia, in some clinics you can find alternatives to traditional veneers: they are called “ultraneers”, “super-veneers”, etc. They are marketed as restorations that do not require grinding of teeth. In reality, minimal preparation is still required.
At the moment, the only type of prosthetics that truly does not involve “drilling teeth” is prosthetics on implants. This type of treatment has proven itself and is successfully used to restore both one missing tooth and the entire dentition.
Orthopedic dentist Dmitry Viktorovich Martynov
Favorites
…
Techniques
Not long ago, a special drill was used to treat problem units. Today, grinding technology has improved significantly.
Several new techniques have been developed that have made the manipulation more comfortable, as painless and safe as possible:
Ultrasonic
Grinding occurs using ultrasonic waves , which are emitted by a high-precision device. The advantages of the procedure include:
- absence of negative feelings;
- minimal risk of damage to hard tissues;
- pulp safety;
- painlessness;
- no heating of dentin and enamel.
Laser
This technique is based on the process of heating water in dental tissues using a pulsed laser. Its effect allows you to easily remove the affected areas with an air-water flow.
The advantages are considered to be high precision of processing, silent operation of the device, absence of damage and heating of tissues.
Disadvantages - there is a minimal risk of infection, the technique can only be used for surface treatment.
Air abrasive
Here, instead of a drill, a mixture of abrasive substance and air is used , supplied under pressure. This force is enough to remove the required amount of enamel and dentin.
The advantages of the technique are:
- safety;
- speed of manipulation;
- minimal heating of tissues;
- processing accuracy;
- no vibration;
- preservation of the maximum volume of healthy tissue;
- painlessness.
But at the same time, air abrasive grinding cannot be used as an independent technique due to the fact that it can only act on surface layers.
Can be used in combination with other methods of preparing teeth for prosthetics.
Chemical
Preparation involves the use of chemically active substances (for example, acids), which, through their action, soften the desired area of enamel.
The positive aspects of the technique are painlessness, safety for healthy tissues, and the absence of heating.
The only drawback is the length of the process (on average, it takes about 30 minutes to process one unit).
Tunnel
This technique is the most common due to its ease of implementation and the ability to accurately control the thickness of the surface being removed.
It is carried out using a special diamond tip (or metal) with high rotational ability.
The only advantage of tunnel preparation is the high precision of processing.
The method has significantly more disadvantages:
- strong heating of the enamel;
- need for pain relief;
- high probability of tissue damage;
- there is a risk of infection.
It is impossible to single out the best method from the entire list. All of them are selected individually for each patient , based on the condition of the oral cavity, examination results, and in accordance with the specific type of defect.
Reviews
Modern methods of tooth preparation have made it possible to carry out prosthetics almost painlessly, quickly and with better quality.
This is evidenced by numerous reviews from patients who have undergone the process of restoring teeth with prosthetic structures.
You can share your experience of restoring teeth with orthopedic structures, talk about the impressions and feelings you experienced before and after the procedure, by leaving a comment on this article.
If you find an error, please select a piece of text and press Ctrl+Enter.
Tags fixed prosthetics prosthetics
Did you like the article? stay tuned
Previous article
The importance of timely detection and elimination of hidden caries
Next article
What can lead to darkening of teeth and how to correct the situation
