Inlays and onlays

An inlay (English for inlay filling) is a tooth filling produced in a dental laboratory, which is inserted into the tooth, usually to treat caries consequences and thereby incurred to reconstruct the tooth defect. An inlay is a perfect fit for the workpiece, which is glued into the tooth, as opposed to a plastic filling material, which is introduced in the form of support means of a soft consistency in the tooth and then cured. An inlay can be made ​​of various materials such as gold, ceramics, electrical ceramics ( combination of gold and ceramics), plastics and more recently titanium.

• 2.1 Dental Procedure
• 2.2 Dental Procedure 2.2.1 Burnt ceramic inlay
• 2.2.2 Cerec method

• 3.1 review

• 5.1 Area Number of inlays
• 5.2 Calculation by GOZ
• 5.3 overall cost

Gold inlay

The dental care by a gold inlays provides both high demands to the dentist, as it were, by freehand shape in the tooth must be prepared with diamond burs, which has no undercuts and at the same time ensuring adequate retention, as well as to the dental technician, the manufacturing process the must strictly comply with them. Dual-surface and three -surface inlays can also be used as bridge anchors use. Thus, the tooth of the abutment tooth in comparison with a full crown is substantially preserved. The perfection of gold inlays is exceeded only by gold foil fillings ( gold fillings).

Dental gold alloy

Pure gold is too soft to make it resistant gold inlays can. To improve the properties, therefore, an alloy is used, which guarantees both the durability, and the necessary processing characteristics. Gold (Au ) are added ( in ) of palladium (Pd ), platinum (Pt), silver (Ag ), zinc (Zn) and small amounts of tin (Sn), iridium (Ir), rhenium (Re), and indium. Depending on the application gold alloys can be processed with different degrees of hardness. For gold inlays are soft to medium-hard gold alloys. On copper as an alloying element is omitted since the 70s of last century, there could oxidize the copper components and discolor so dark. The alloy components also affect the gold color that it looks yellowish or reddish.

Alloying constituents of soft, copper-free dental gold alloys

• Au 78-96 %
• Pd 0-4 %
• Pt 0-10%
• Ir, Sn, Zn <1%

Alloying constituents of medium-hard, copper-free dental gold alloys

• Au 78-92 %
• Pd 0-3 %
• Pt 3-14 %
• Zn 0-3 %
• Ir, Sn, Re, in <1%

Feingold has 24 carats. Dental gold alloys, in contrast, 20-22 karat alloys. The cost of a gram of a dental gold alloy are still higher than that of a gram of fine gold, on the one hand incorporate the additional cost of the alloy development and production and on the other hand punched dental gold in 1 gram platelets is hallmarked and marketed.

Dental preparation

First, the decay is - possibly under local anesthesia ( numbing ortlicher ) - completely removed from the cavity. Then the tooth to receive an inlay is prepared in the form of ( ground ). It is intended to create a "box", therefore it is called this form of tooth preparation box preparation. The box is made slightly conical prepared tooth walls ( cone angle of about 6 ° ) to cause a retention form. The problem area in the production of the so-called margin line, the region separating the prepared part of the unprepared. In gold inlays, inter alia, a feather edge or carving sharp edges and angles ( Tucker technique, see Figure ), and thereby given the opportunity Finierens is through special preparations, an accurate marginal fit possible, ensuring the tightness of the inlay. After an impression is taken of the tooth, the model is used to manufacture.

Dental manufacturing

In this model, the inlay is first modeled in wax. The wax inlay is then embedded into a mold and melted. In the cavity thus formed, the liquid gold alloy is introduced. The blank is then trimmed and polished. The production of inlays provides the dental technician high demands, because the many individual steps are all faulty. The trick is that all occurring " error " at the end of the manufacturing process cancel each other and thus the fit of the finished inlays is guaranteed. Representing the production problems should be mentioned in the following example: The setting process of the gypsum for embedding the wax inlays must lead to a larger cavity than the size of the final inlays, since the gold alloy after casting shrinks when it cools. Otherwise it would be too small in the end.

Dental insertion

Gold inlays are fixed with resin cement or plastics in the tooth. The dentist checked and corrected the right combination of the teeth bite ( occlusion), examines the points of contact with the adjacent teeth so that no food between the teeth can be bitten and defines the edges of the tooth enamel to achieve maximum tightness.

Assessment

Among all currently available materials is the classic inlay material gold, which is processed in the form of a gold alloy, unprecedented with respect to its durability and resistance to oral conditions. However, may break away due to excessive expansion of the inlay preparation a cusp, as conventionally cemented gold inlays unlike glued ceramic inlays not the natural tooth structure stabilization ( internal splinting ).

The durability of a precision manufactured gold inlays is basically unlimited, unless produced at a different location of the tooth decay or a piece of the tooth breaks off.

Ceramic inlay

Ceramic inlays are made of an unbreakable ceramic, which can be made in different ways. The advantage over a gold inlay is particularly the color, since the ceramic inlay in tooth color of the tooth can be customized. Furthermore, the dentin adhesive bond between dentin and ceramic and the mechanical- retentive bond between enamel and ceramics create a stabilization of weakened ( too thin ) Dental walls ( cavity walls ).

A dental procedure

The removal of carious substance and the preparation of the tooth cavity do not differ from the preparation for a gold inlay. However, some features are observed. Thinly tapering edges, as are desired by the gold inlay in the form of a so-called spring edge are to be avoided. There are to avoid rough edges, that is, the type of preparation is different from the gold inlay on the cavity due to rounding. The strength of the ceramic inlay should, as that of the remaining tooth structure be at least 2 mm. The preparation angle is slightly conical run, as the gold inlay (6 ° to 10 °). All mentioned measures are intended to minimize the risk of breakage. The tooth colors determined by means of a color scale. Mixed colors are possible only with handmade inlays.

Dental Procedure

Depending on the manufacturing process, different methods can be distinguished:

Burnt ceramic inlay

There are different types of ceramics for all-ceramic restorations available:

• Silicate glass ceramics
• Alumina ceramic
• Zirconia ceramic

Ceramic inlays are made ​​either by layered ceramic burning in the oven or by pressing a heated glass -ceramic blank into a hollow mold.

Cerec method

CEREC ( Chairside Economical Restoration of Esthetic Ceramics or CEramic REConstruction ) is a CAD / CAM method for reconstructing Zahnkauflächen. Using an intra-oral camera is scanned in an optical impression instead of a conventional impression with impression material of the tooth to be restored and a three-dimensional model is calculated. This can be displayed and edited on the monitor. Subsequently, the inlay is milled by a robot from a ceramic block. Alternatively, the optical impression can also be made by a dental technician from the plaster model and made ​​of this, because Cerec systems there are only a few dental practice since their acquisition and maintenance are costly.

A detailed color design that takes place, in the preparation by a dental technician, is not given in milling from a given ceramic block. It is selected from a range of ceramic colors. The fitting accuracy of Cerec inlays applies - also because of the still imprecise digital impressions - as less than that of a handmade inlays. We rely here on the mounting plastic. A friction of the workpiece to a stop and a precise marginal fit is not desirable ( can not be achieved production reasons ) because marginal gaps are filled by the plastic.

Dental insertion

Ceramic inlays are usually bonded with composite into the tooth. For this purpose, the inner surface of the ceramic inlay is silanized, slightly the enamel etched with phosphoric acid and the dentin provided with a dentin adhesive. The light- curing composites are irradiated with halogen light. The other adjustment is the procedure for inserting a gold inlays.

Assessment

At higher effort and cost of the inlay against a plastic filling with composite one often expects a longer service life. However, this can not be shown in all long-term studies for the case of ceramic inlays.

Ceramic is generally well tolerated. A very small for the patient Allergisierungsgefahr proceeds from the glue on the plastic base, with the method of attachment of ceramic inlays. If the ceramic inlay perfectly matched in color, it is difficult to remove it again, should this become necessary. The transition between tooth and ceramic inlay is then difficult to detect. A slight ( barely recognizable from the laity ) Color shift is therefore desirable. The greater hardness of the ceramic inlay can cause damage to the opposing dentition. In some places referred to a radioactivity of the ceramic inlay, starting from the element zirconium component is negligible (about 0.01 mSivert from 1 gram inlay over 2-3 mSivert by natural radioactive background radiation ) per year.

Plastic inlay

Plastic inlays are made ​​of composite and are similar in function and aesthetics as the ceramic inlays. The material is slightly softer, is therefore to be expected from a higher abrasion shortening the life of the inlay. Plastic inlay can be matched to the natural tooth color. They are pressed under high pressure in the laboratory. The attachment is similar to ceramic inlays with Dentin-/Schmelz-Adhäsivmaterialien.

Assessment

Similar to ceramic inlays and the durability of composite inlays compared to composite fillings plastic in some long-term studies is assessed as not durable or durable as minimal, but this was not considered as justifying the higher price and effort.

Titanium inlay

Titanium inlays are well-tolerated by the material here, but have a silver-gray color. The processing of titanium requires a special preparative equipment of the dental laboratory. The technology is not yet mature. For better optics titanium inlays are veneered with ceramic ( coated ).

Costs

Inlays are not part contractual dental care, the patient would be entitled to a cash register. However, he is entitled to the funds performance if he opts for a more complex care. The additional costs agreement to filling therapy is regulated in § 28 SGB V. It reads:

" Choose insured for dental fillings a beyond supply, they have to bear the costs themselves. In these cases, by health insurance comparable cheapest plastic filling settle in kind. In cases of sentence 2 is to meet before the start of treatment, a written agreement between the dentist and the insured. The additional cost does not apply to cases in which intact plastic fillings to be replaced. "

The settlement of inlays performed according to the fee schedule for dentists ( GOZ ). For insured patients, the cost of a cash benefit shall be deducted by the dentist of the bill and billed to the dentists' association with the insurance company. If the insured has elected the reimbursement, then he can recover the cost of the contract performance of his health insurance. Dental insurance may reimburse inlay costs depending on your plan.

Area Number of inlays

A distinction inlays, as well as other dental fillings, according to their size. Teeth in the posterior region ( premolars, molars ) have five areas:

• Outside ( vestibular or buccal),
• Inside (oral or lingual mandibular, maxillary palatal )
• Occlusal surface ( occlusal) and
• Front and rear ( proximal, or mesial and distal ).

Cervical fillings and inlays are made in the edge area of ​​the tooth to the gum out. These are called cervical location.

The surfaces are abbreviated with the first letter of the Latin names. For example, a MOD inlay an inlay which includes the tooth surfaces of mesial, occlusal, distal.

Depending on whether one, two or more surfaces of the tooth must be supplied with an inlay, a distinction is made single-surface, two -scale and multi-surface inlays.

Calculation by GOZ

The design of the multiplier ( 1-fold to 3.5 -fold) according to the following criteria:

" Within the framework charges the fees are to be determined in consideration of the difficulty and time involved and the circumstances of the individual lines in the execution of its reasonable discretion. The difficulty of the individual performance may also be due to the difficulty of the case of disease; Design criteria, which have already been taken into account in the specification have here to be disregarded. The 2.3 times the listed rate represents the average on the difficulty and time required performance; exceeded this rate of charge is permitted only if the specific features of the design criteria specified in sentence 1 warrant it; Services with below average difficulty or cost shall be calculated with a lower fee rate. "

By a written fee agreement pursuant to § 2 GOZ a higher multiplier than 3.5 can be agreed before the start of treatment times. For insured patients, two written agreements are to be taken in this case, on the one hand an agreement that a supply of the additional costs Regele narrowing (see above) takes place and on the other that a maximum rate exceeding agreed.

Total cost

The total cost of inlays are made up of several factors:

• The dental fee for the inlay (see table)
• The dental fee for accompanying services (eg local anesthesia, removal of deep caries, special measures, etc. )
• The cost of materials (eg, impression material, ceramic blank )
• Plus the cost of dental technology. VAT.
• Plus the cost of the gold alloy ( according to daily price ). VAT.

In the field of dental technology and dental expenses of the reduced VAT rate of 7% applies.

Demarcation

The inlay is usually used for treatment of cavities in the posterior region and does not replace parts of the occlusal surface, but the cusps of the tooth. Become the kaukrafttragenden hump covers, then one speaks of a Onlay ( dome filling). This broken, weakened tooth walls are supported by additional coupling About (only ) replaced those cusps of the tooth bearing the bite force. It is a kind of larger inlay. The overlay überkuppelt all cusps of the tooth and replaces the entire occlusal surface. The partial crown refers addition the tooth walls partly with a. The definitions are not always clear, since the differences in size of the inlay on the onlay, overlay on the way to partial crown are partially blurred.