DE3310518A1 - Integral embedding moulding for sewn and polished sections (microscopy) - Google Patents

Abstract

The invention relates to an embedding moulding, in particular for MMA polymer embedding of sawn and polished sections in medicine and biology, primarily for cases where hard substances containing soft tissue components or, alternatively, alloplasts (for example, implants) are to be prepared. In this case, as a departure from the standard methods, the embedding moulding itself becomes a component of the specimen after curing. With their more solid outer rings, the polymer components of the acrylic moulding, which have been fully polymerised using industrial techniques, are preferably suitable for the abovementioned group of sections. The high proportion of fully polymerised acrylates reduces the risk of bubble formation and toxications which are harmful to health. As a result of the adequate UV transparency, it is also possible at the same time to use commercial adhesives which have a cost-saving effect on the preparation measures, in addition to the known basic substances. This method of embedding consequently results in an improved method of preparing sewn and polished sections.

Description

that e -permeable embedding together with customary types of substances time and material-saving one can earth and for special Preparation process an outer ring of the ho Test specimen is formed.

The invention relates to an embedding mold, in particular for sawing and Cut preparations of biological hard substances, alloplastic materials and parts of soft tissue in medicine, according to the preamble of claim 1, and a method for embedding of sawing and grinding preparations of biological tissue.

Tissue that cannot be cut, such as bones, enamel, dentin and implants, but also hard substances in biology are increasingly used for the microscopic Evaluation prepared by sawing, grinding or freezing processes.

This procedure requires embedding the preparations in plastic necessary. Odontological hard tissues are used for improved infiltration the agents previously sectioned.

Due to the water-containing proportions, tissue samples are required to maintain fine cell structures, complex, sometimes lengthy embedding processes. After Fixation follows a continuous dehydration over the increasing alcohol or Acetone series. Then the absolute alcohol in the final stage becomes the anhydrous Preparation replaced by plastic, which after extensive infiltration and polymerization leads to a homogeneous test specimen. For hard substances with a poorer penetration rate this procedure usually takes a few days to complete. These methods are in well known in histology, pathology and biology.

Acrylates and epoxides are the preferred embedding plastics. Epoxies show better kie lmann garbsen 2 Volume stability and radiation exposure in electron microscopy. However, since they are very slow Penetrate tissue, low-viscosity ones are preferably used for large-area embeddings Acrylates (MMA), the polymerization of which takes place through physical measures, such as heat and light, let in.

By varying the proportion of methyl ester and butyl ester, one sets the desired blocked one, especially for microtome sections of embedded Soft tissue has importance. Saw cuts in thin layers produce better results, if the embedding medium has a high strength. Microsection specimens show at The solid outer zone does not have the usual edge rounding that is found in metallography Attempted to prevent this by using harder packing in the edge area.

During the polymerization, the acrylates show pronounced shrinkage, the bi-sensitive tissue structures for artifact formation with falsification of the Evaluation can lead. Due to the exothermic hardening process, they are formed through physical (partially reduced heat dissipation) and chemical intermediate Reactions with individual parts of the preparation bubbles, especially when the initial temperature is too high and large test specimens are created.

This is why some users prefer curing with UV light than Initiator, which means that vacuums are formed even at lower ambient temperatures is prevented.

A prerequisite, however, is that light of this wavelength is the embedding medium achieved.

The shape of the test specimen is made by reusable embedding molds made of PA, PVC or similar materials. Glass containers are also used or gelatine capsules, which are destroyed after hardening.

The object of the invention is to provide an embedding mold garbsen 2 garbsen 2 to be indicated by the plastic embedding (Acrylic) biological hard tissue the artifact formation by the following measures minimized if pre-cut specimens are prepared using the sawing or grinding process should be: 1. The reduction of the hardening plastic content to a minimum, whereby damage in the tissue and vacuoles occur less.

2. The embedding form integrates with the hardening tissue block chemically and physically. As both the enveloping form and the embedding medium consist of the same substance, a homogeneous new test body is formed. The acrylic surface initiates the polymerization of the liquid embedding medium accelerated.

3. The use of the harder outer zones by the proportion of the industrial manufactured, stronger material of the form leads to optimal results when sawing and cut objects.

4. By the deepening of the shelf in the center and the pronounced The sawtooth structure of the surface hardened, especially presectioned odontological ones Hard substances evenly. The soft tissue parts lie through the previous saw cut (Pulp), surrounded by hard substances, isolated. This leads to polymerization delays and disorders. Through the surface of the specified load-bearing floor for the fabric will be a sufficient connection with the remaining, predominant shares of the (still liquid) embedding medium.

5. Unstable samples can be caused by acrylic holding rods, which are also Be part of the test body, be aligned.

6. UV light components can penetrate the embedding form and act as initiators the polymerization of the central methacrylates starts at room temperature set.

k ielmann garbsen 2 This allows besides the known Basic substances, which usually require additional processing work (e.g.

Destabilize) require commercially available plastic adhesives (ACRIFIX 92), which harden through UV light, are used to save time for embedding will.

The object of the invention is given by what is stated in the claims Invention solved. Advantageous further developments of the invention are set out in the subclaims specified.

By selecting correspondingly large embedding forms, overview images can be obtained the embedded samples, as the environment is facilitated by the bubble-free, prefabricated Material is predetermined. In particular, show large volumes during the polymerization uncontrolled reactions due to the formation of vacuums.

Top surfaces of the sample cylinders, polished on both sides, result in demonstration models for training and patient information.

Presectioned samples can be processed further directly, as through the cut surface of the sample the tissue parallel to the base of the test specimen lies.

When grinding and polishing, there is a stronger outer edge more even removal of the examination plane.

The advantages associated with the use of the embedding form can be limited equally for epoxies of different hearing use by in turn a harder material is selected for the embedding mold.

Through the use of the very tissue-friendly, fully polymerized acrylates as a semi-finished product, the portion of the mucous membrane and thus health-damaging Basic substances are severely restricted, so that there is less risk for the laboratory staff Handling results.

kielmann garbsen 2 If soft tissue with microtome cuts are to be processed, the portion of interest can be removed with a milling machine or expose the hole saw. Thus, the aforementioned type of embedding clears all techniques the preparation of preparations, such as sawing, milling, grinding, polishing and cutting.

The invention is explained below using an exemplary embodiment explained in more detail.

Fig. 1 shows a cross section of the embedding mold, alternatively with Sealing plug or acrylic rod fixing lid.

The cylindrical arrangement of the embedding mold (1) is ideal for grinding and saw preparations common in medicine and metallography. The chucks of the Processing devices are matched to the cylindrical shape.

Deviating from the usual methods in which the embedding form only the shape of the 'block prescribes and is then separated, consists in the present Case the embedding form made of PMMA (acrylic) and forms together with the embedding medium (Methyl methacrylate and additives) after the polymerization a uniform Test specimen.

Due to the high proportion of already polymerized material, the Very little risk of blistering.

Dps tissue to be examined is placed in a center hole (2) different diameters, tailored to the most commonly used preparation size, and rests on a base surface (9) which is deliberately structured in a sawtooth-like manner when it is turned out and additionally shows a pronounced depression (8) in the center. To record larger amounts of tissue and a reduction in the amount that polymerizes. Embedding medium the centering hole in the area of the contact surface is additionally larger in diameter (10) turned out, tapers at the top and goes into the diameter of the hole kielmann garbsen 2 garbsen 2 above. Because of this geometry of the support surface Methacrylate is also sufficient for tissue that has been prepared flat beforehand by means of a saw cut surround. Bubbles that form can rise better. Especially with odontological ones In conventional embedding forms, hard tissue is insulated from the central pulp soft tissue, because of the surrounding hard substances (dentine, enamel,) and the flat surface the sectioned sample is not connected to the embedding medium.

The sealing plug (3) made of acrylic should have sufficient play in the Have a hole and be beveled on its base, so that when it is inserted existing air bubbles can rise to the surface.

The top surface of the acrylic mold is also turned out (4) so that Commercially available lids of reusable embedding molds can be put on. Thus, the undetermined inhibitor or Initiator effect suppressed. In addition, when the cover is put on, the embedding form be placed in a vessel1 that is filled with an oxygen-free gas, remains on the ground due to a higher weight than air and thus the air content of the Displaced embedding form.

There is no contamination after the lid has been put on and removed the embedding medium with oxygen. Since only small amounts of gas are required, are Commercial forms in spray cans are already sufficient.

The aforementioned examples relate to a flat edition of the Preparations on the bottom of the mold. Unstable hard tissue samples that were found in the dental, oral and orthodontics occur very often, are held by a lid (5), which is characterized by central holes (6), at least 3, in which Acrylic rods (7) are held. Samples arranged vertically are adequately fixed in this way. The acrylic stobe combine homogeneously with the embedding medium.

klelmcnn garbsen 2

Claims (10)

PATENT CLAIMS: öji embedding form, especially for use in the medicine for MMA embedding of hard tissue for sawing and grinding preparations, thereby characterized in that it is a circular body with a central hole forms both the embedding form and part of the test specimen or the embedding. 2. embedding mold still claim 1, characterized in that the centering hole ends shortly before the longitudinal expansion of a Vollstob semi-finished product and the support for the samples forms. 3. embedding mold according to claim 1, characterized in that this made of acrylic (PMMA, Plexiglas). 4. embedding mold according to claim 1, characterized in that the bottom the centering hole has a recess in the center. 5. embedding mold according to claim 1, characterized in that the surface the sample support is turned off like a sawtooth. 6. embedding mold according to claim 1, characterized in that the sample ouflage surface is expanded by turning out to the level of the centering limit and after tapers converging at the top to the drilling diameter. 7. embedding mold according to claim 2, characterized in that a sealing plug forms the upper end of the test specimen from the same material. 8. embedding mold according to claim 2, characterized in that the sealing plug is sloping at the bottom. 9. embedding mold according to claim 3, characterized in that a reusable Lid with central holes to accommodate vertically arranged acrylic rods forms the upper conclusion. 10. Process for the MMA embedding of ground-joint and grinding preparations in microscopy, characterized by kie lmann garbsen 2 that a UV-permeable embedding form together with commercially available UV-curing adhesives Can be used to save time and material and for special processing methods a harder outer ring of the test specimen is formed.