Microprosthetics of teeth in Astana: types of inlays, stages and materials

How an inlay is made and how a filling is made

A filling is shaped directly in the mouth. The dentist prepares the tissue, applies composite in layers, and cures it with a lamp. The shape is created by hand, so precision depends on skill and conditions. An inlay is made in a laboratory from an impression or a scan. First the cavity is prepared, an impression is taken, and a temporary restoration is placed. The microprosthesis is milled or cast from the model, then cemented. Microprosthetic restoration differs in that the replacement part is created outside the tooth rather than built up inside it. Hence the different fit. A filling adheres to the walls through the adhesion of the composite. An inlay fits into the cavity like a key in a lock. The gap between it and the tissues is minimal because the model is made from an accurate impression. Material: ceramic, composite, metal. Each behaves differently under load. A composite filling absorbs moisture over time and changes color. A ceramic inlay holds its color. But it also has limitations — it depends on the clinical picture.

When a filling no longer holds

What an inlay restores more precisely

An inlay reproduces the anatomical shape of the tooth from a model. Cusps, fissures, contact points — all of this is predetermined. A filling is sculpted in the mouth, and achieving the same geometry is more difficult. Especially on chewing teeth, where every fissure matters. The precise shape distributes chewing load more evenly. This does not mean that an inlay is always "better." It has its own indications and its own limitations. In a small cavity, a filling will do just as well, and the visit will be shorter. In a large one, an inlay preserves the remaining walls. The marginal fit of a laboratory-made restoration is tighter because the cement fills a minimal gap. With a filling, the margin may become pigmented over time. But an inlay is not eternal either: the cement ages, and then it is recemented. What to choose is decided by the dentist based on the X-ray and the extent of destruction. Sometimes a filling is enough. Sometimes a crown is needed. An inlay is an intermediate option.

What an inlay in the visible zone is made of

In the anterior region, ceramic is used more often. Whether pressed or layered, it transmits light similarly to enamel, and the margin with the tooth tissues is barely visible. Zirconia is stronger but less translucent, so in the visible zone it is used with reservations — the dentist decides based on the clinical picture. Composite materials are cheaper, but over time they darken at the margin, and on incisors this is noticeable. Metal is not used in the anterior group because of its color. A post-and-core buildup, whose price depends on the material and the amount of work, is seen less often in the visible zone: it is needed when the tooth crown is destroyed and there is nothing to hold a filling. Then a crown is placed over the core, and it forms the appearance. A separate issue is wall thickness: the more tissue is preserved, the more natural the result looks. If the wall is thin, it is reinforced, otherwise it may chip under load. All of this is assessed from an X-ray and in the mouth, not from a photograph.

How shade and translucency are selected

When an inlay is not placed on an anterior tooth

There are situations when a microprosthesis is not used in the visible zone. If more than half of the crown is destroyed, the walls are thin, and there is nothing to hold the structure — then a crown is discussed. With a crack extending below the gum, the prognosis depends on the clinical picture, and the dentist makes the decision. Thin enamel and a tendency to chipping also limit its use: the load on an incisor during biting is high, and a microprosthesis does not reinforce the remaining walls the way a crown does. An inlay is not placed on a tooth with mobility or inflammation in the apical area — the cause is treated first. Insufficient height is also an obstacle: if only a thin strip above the gum remains, fixing the structure is difficult. In some cases, a post-and-core buildup helps, but its use in the anterior region is limited by esthetics. Sometimes the choice falls on direct composite restoration — it is cheaper and done in one visit, although over time it requires renewal. The final option always depends on the condition of the tissues, the bite, and how many teeth are involved in the restoration.

Structure of a post-and-core buildup

A post-and-core has two parts, and they work together. The inner part — a post or several posts — follows the shape of the root canal and holds the structure in the root. The outer part — the core — reproduces the shape of the tooth that has been prepared for a crown. Both parts are cast or milled as a single piece, with no joint or seam. Hence the name: the component forms the core onto which the crown is later seated. The material is chosen according to the situation: metal, zirconia, less often others. The post must not be thicker than the canal, otherwise the root will crack under load. The core must provide a smooth surface with the correct taper, otherwise the crown will not seat tightly. The tooth is prepared in advance: the canal is widened, the walls are smoothed, and all of this is visible on the image. The dentist assesses how much hard tissue remains above the gum. If there is little, the post-and-core takes over what the tooth itself used to support.

Requirements for the root and canal

Post-and-core and crown: two stages

This is not one structure but two, and they are made one after the other. First the canal is prepared and an impression is taken or the tooth is scanned. Then the post-and-core itself is made in the laboratory. It is tried in, the fit is checked, and it is cemented into the root with permanent cement. Only after that is an impression taken for the crown — now from the finished core. The crown is milled and seated on top. Sometimes both stages are combined in time, but this depends on the clinical picture. Working in separate stages gives the dentist a chance to check each step: first the fit of the post-and-core, then the crown margin. If something is wrong, the error is visible before cementation, not after. The cost of the microprosthesis is a matter of a separate estimate; what matters more here is this: the post-and-core and the crown are a sequence, not a single procedure.

What is removed during preparation

First, softened dentin and any old filling are removed. Necrotic tissue is not left under the restoration: it is a source of inflammation and a cause of decementation. The dentist then treats the cavity walls to remove overhanging enamel edges. Weak areas that will not withstand the load are also excised. The floor and walls are made smooth, without undercuts, otherwise the impression cannot be taken correctly and the post-and-core will not seat tightly. How much is removed depends on how deep the decay has gone and how badly the tooth is destroyed. If the process has reached the pulp, endodontic treatment is carried out first, and only then is the cavity shaped for the microprosthesis. Sometimes a metal post-and-core is additionally placed to rebuild the core. A separate stage is creating a shoulder or bevel along the cavity margin. This is needed so that the boundary between the restoration and the tooth tissues is sealed. Without a shoulder, the margin of the post-and-core may overhang, and plaque accumulates there. The dentist works with magnification: a microscope helps to see the boundary of the lesion and avoid removing too much. A scanner or impression material captures an exact copy of the cavity.

What determines the amount of preparation

When the dentist chooses a crown instead of an inlay

If after removing the affected tissue few healthy walls remain, the inlay won't withstand the load. In that case a crown is indicated — it covers the tooth entirely. The dentist assesses not only the extent of destruction but also cracks and the condition of the roots. With a significant defect of the coronal part, a post-and-core inlay under the crown is sometimes needed: it restores the support on which the crown will sit. The decision is made based on the X-ray and the clinical picture. Sometimes a tooth looks intact on the outside, but inside the walls are thinned. Then the plan is changed during the preparation stage. This is normal: the final choice is made when the dentist sees the cavity after preparation. The patient is told about both options in advance so they understand the possible scenario. If the walls are preserved and the cavity is shallow, the inlay remains a viable option. When in doubt, the dentist may refer for a CT scan to assess tissue thickness in three dimensions.

Impression or intraoral scan

The classic route is an impression tray and impression material. The material fills the cavity, sets, and produces a negative from which a plaster model is cast. The method works, but accuracy depends on how the material flowed, whether there were bubbles, and whether it deformed on removal. An intraoral scanner works differently: a camera captures the surface of the tooth and adjacent tissues, and software assembles a digital model. No impression is needed, there are fewer retakes, and the data goes straight to the laboratory. Which to choose in a particular case is decided by the dentist based on the clinical picture. If the tooth is destroyed deep under the gum, the margin sometimes can't be read by either the scanner or the material, and then the issue is resolved differently. An inlay is a small restoration, and any inaccuracy at this stage is costly.

How the inlay is made in the laboratory

Try-in and fit check

The finished inlay is tried in the oral cavity. The doctor checks whether it seats fully, whether there is a gap along the margin, and whether it interferes with the adjacent teeth. The thin margin is assessed visually and with an instrument, if necessary under a microscope. If the fit is incomplete, the inlay is adjusted in the laboratory or remade — it cannot be placed with a gap, as saliva and bacteria will get in. Sometimes the bite is also checked: the inlay must not raise the occlusion. Next comes cementation, but that is already the next stage. How tightly the restoration seats depends on the clinical picture and on how the cavity margin is read. The contact points with the adjacent teeth are assessed separately: too tight a contact creates pressure and discomfort, too loose a one leaves room for food to get trapped. If the inlay interferes with the antagonists, it is adjusted for occlusion. All findings are recorded and sent to the laboratory so that corrections are made before cementation, not after.

Metal inlays

Metal is the oldest and most predictable option. Alloys based on cobalt, chromium, or gold withstand chewing load well, do not crumble under pressure, and cost less than ceramics. The downside is color. A metal inlay is visible through the enamel if the tooth wall is thin, and over time a dark rim may appear around it. For posterior teeth this is often not critical. For anterior teeth it is noticeable. Metal is suitable when a large volume of tissue needs to be restored and aesthetics take second place. The doctor looks at the thickness of the remaining walls and at how the inlay will redistribute the load. If a metal inlay is already in place and the color of the gum is a concern, this is a reason for an examination, not for an urgent replacement. The question of price is settled after the examination and an X-ray, not based on the name of the material alone.

Comparison of materials by properties

What is chosen for anterior and posterior teeth

For anterior teeth, color and translucency matter more. E-max transmits light similarly to enamel, so the boundary between the inlay and the tooth is less noticeable. Zirconia is white but less translucent, and on incisors it may look more opaque. A metal inlay is rarely placed on an anterior tooth — because of its color. For posterior teeth, strength comes to the fore. Here metal and zirconia withstand the load better than E-max. Zirconia does not darken at the margin, unlike metal, and does not conduct cold the way an alloy does. But it is harder, and this affects how the opposing tooth wears. The choice depends on the clinical picture: how much tissue remains, how the tooth sits in the row, and whether there is a habit of clenching the jaw. The doctor decides based on the X-ray and after the try-in. Sometimes the same tooth can be restored with two different materials — with a different prognosis.

About inlays and fillings

The difference between a filling and an inlay is not in size, but in how the load is distributed. A filling fills the cavity and is held by adhesion to the tooth tissues. An inlay is a separate piece, made from an impression or scan and fixed in the prepared cavity. It covers the walls and transfers chewing pressure differently. Therefore, an inlay is more often considered where a lot of tissue is destroyed and thin walls may not hold up. A filling is appropriate for small defects. The decision depends on the clinical picture, not on the patient's wishes. Sometimes the doctor sees that the wall is preserved but thin, and suggests an inlay. In another case, the cavity is small, and a filling is enough. No option is universally better: each has its own indications. An inlay is not a replacement for a crown. If the tooth is almost completely destroyed, other solutions are discussed.

On preparation and materials

Preparation begins with diagnostics. The doctor looks at the images, assesses the condition of the root, gum, and neighboring teeth. If there is inflammation, it is treated first. Then the cavity is prepared: affected tissues are removed, walls are shaped with the future piece in mind. An impression or digital scan is sent to the laboratory. There, the inlay is modeled and manufactured. The material is chosen according to the situation. Zirconia is strong and aesthetic, but requires certain conditions. Metal is reliable in high-load areas, but noticeable. E-max provides good aesthetics on front teeth, but is not always suitable for molars. No material is universal. The doctor considers which tooth, what the load is, and what matters to the patient. Sometimes the choice is limited by the clinical picture. For example, with insufficient wall height, some materials will not work. The final decision is made after examination and imaging.

About the doctor's decision

The choice between a filling, an inlay, and a crown is a clinical task. It is decided by the doctor based on the image and after examination. The patient can express preferences, but cannot prescribe a method for themselves. The doctor assesses the extent of destruction, the condition of the root, the bite, and the load on the tooth. They consider how long the tooth can function in the chosen restoration. Sometimes an inlay is possible but not advisable. In another case, it saves a tooth that would otherwise have to be extracted. The prognosis depends on the clinical picture. No method gives an absolute guarantee. If the doctor suggests an inlay, it means that in their assessment it is suitable. If they suggest a crown, there are reasons. Questions should be asked at the appointment: why this option, what alternatives exist, what will happen to the tooth next. An open conversation helps to understand the logic of treatment. The decision is always individual.