Dentistry – Method or material for testing – treating – restoring – or... – By lining or coating
Reexamination Certificate
2001-05-18
2004-03-02
Manahan, Todd E. (Department: 3732)
Dentistry
Method or material for testing, treating, restoring, or...
By lining or coating
Reexamination Certificate
active
06699040
ABSTRACT:
RELATED APPLICATIONS
This application claims the benefit, under Title 35, United States Code, Section 119(a)-(d) and (f), of German Patent Application No. 198 27 417.3, filed on Jun. 19, 1998.
This application claims the benefit, under Title 35, United States Code, Section 365, of International Patent Application No. PCT/EP99/03778, filed on Jun. 1, 1999.
FIELD OF THE INVENTION
The invention relates to a material for differently modifying the optical properties of different cells, to an apparatus for the application of such a material, to a diagnostic apparatus for determining the optical properties of cells which have been exposed to such a material, and to an apparatus for irradiating cells whose optical properties have been differently modified with such a material.
BACKGROUND OF THE INVENTION
Periodontosis is a widespread disease of the attachment apparatus of the teeth. Periodontopathies are caused by bacteria located in periodontal pockets (subgingivally). Some of these are bacteria which are bound adherently to the root surface and are usually Gram-positive and calcified to give concrements (subgingival calculus), and the others are bacteria which face the soft tissue of the pocket, are non-adherent and are usually Gram-negative, and which, for example, in part are motile in the pocket fluid. It is precisely these motile bacteria which play an essential role in the progression of periodontitis.
During the progression of periodontitis, the bacteria may migrate through the pocket's epithelium and penetrate into the subepithelial connective tissue, so that they surround the inflammatory infiltrate. Complicated interactions occur with the patient's immune defenses which are massively [lacuna] at this point and which lead, via (micronegroses, purulent abscesses or as reaction to the immune interaction for example through activation of osteoclastic endogenous cells, to loss of periodontal supporting tissue and development or deepening of a periodontal pocket and/or retraction of the gingival soft tissue. Particularly important in this connection are processes which take place deep inside the pocket or in problem regions such as, for example, the root furcation.
Recommended to date for reducing microbes in the pockets are mechanical cleaning techniques (for example scaling, curettages, cleaning with ultrasonic instruments) or simple pocket irrigations. Systemic administration of antibiotics is associated with considerable side effects, firstly because of the broad spectrum of the causative bacteria, and secondly because the bacteria are located outside the blood circulation. Local administration techniques through application of the antibiotics directly into the periodontal pockets often have an unreliable effect because diffusion into all the pocket regions is inadequate or deposition does not last long enough or the level of the active substance combination is inadequate. Antibiotics are therefore normally administered only as a measure supporting conventional, usually mechanical, procedures.
Because of the complex geometries of the affected periodontia or periodontal pockets, access to the diseased tissue regions is impeded, and the desired reduction in microbes is often not achieved. The consequence is after various time intervals, depending on the patient's immunological predisposition which is usually affected, recolonization of a previously treated pocket with a recurrence of the disease. It is particularly difficult to reduce microbes in the region of the infiltrated pocket epithelium and the adjoining connective tissue.
The first requirement for improved therapy is to have more detailed information about the current status of the disease to allow a better prediction to be made about the future development of the disease, especially the occurrence of acute episodes of the disease. It is to date possible to identify a previously active pocket only subsequently on the basis of pus discharge from the pocket. If this identification is possible, however, loss of supporting tissue has already occurred. Bacterial genetic testing which has recently been employed for the diagnosis of individual bacteria in periodontal pockets is costly and requires several days for evaluation. For these reasons, it is unsuitable for routine applications. It is moreover possible to derive information only about the genomes of the bacteria from such testing. Distinction according to the metabolic activities of the bacteria which cause periodontal disease is, however, impossible.
Examples of a periodontal procedure are evident from U.S. Pat. Nos. 5,422,093; 5,234,940; 5,211,938 and 5,079,262. These involve the identification and subsequent treatment of malignant and nonmalignant tissue abnormalities using aminolevulinic acid. This is used in the form of an aqueous active substance solution. Excitation of cell fluorescence in the violet region (375 nm to 440 nm) leads to a red fluorescence being observed. An observation filter is used to filter out the diffusely reflected blue-violet excitation light, and the metabolically active tissue region is seen red against a background which appears slightly greenish (intrinsic fluorescence of the healthy tissue).
The rate constant with which metabolism takes place in the cells makes it necessary for the active substance to remain over a prolonged time (at least 15 minutes, typically 120 minutes) essentially unchanged in contact with the tissue.
SUMMARY OF THE INVENTION
The invention is therefore devoted to the problem of obtaining, in a simple manner at low cost and rapidly, information about the extent of a periodontitis, in particular also being able reliably to identify periodontitis in the initial stage.
To solve this problem, the invention indicates a material for differently modifying the optical properties of different cells (healthy tissue, diseased tissue, bacteria) which comprises firstly a substance which modifies the optical properties and secondly a basic material which is mechanically stable for a prolonged period under the conditions prevailing at the sites affected by periodontitis in a patient, and thus can release the modification substance over a prolonged period at the desired site. The proposed basic materials which are stable over a prolonged time under use conditions are viscous fluids, a gel, a two-dimensional or three-dimensional porous substrate or a material which hardens in situ (for example plastic film).
Materials which have different effects on different cells in a property typical of them are known in other medical sectors. Thus, for example, radioactive traces are used to identify cancer cells because they accumulate preferentially in the latter because of the greater metabolic turnover. Other modification substances are those which intervene directly in cell metabolism, stated more accurately in porphyrin biosynthesis. Administration of suitable modification substances, which are described in detail hereinafter, leads to intensification of the fluorescence spectrum of metabolically active cells. This makes it possible for these cells also to be determined quantitatively and in their spatial distribution, and the therapy can then be planned on the basis of this information.
It has now been realized that the technique developed in another medical sector for identifying diseased cells can also be employed in the periodontitis sector if the basic material used does not mix quickly with saliva and thus keeps the modification substance at the required site. Suitable for this purpose according to the invention are fluids having sufficient viscosity, gels, flat porous substrates such as wovens, nonwovens and the like or else three-dimensional porous substrates which are able to take up in their cavities particles of the modification substance or a concentrated solution thereof and thus release the modification substance distributed over a prolonged period. Another alternative consists of materials which harden in situ, such as film formers which bind or entrap the modification substance on the surface.
Adv
Hahn Rainer
Irion Klaus
Karl Storz GmbH & Co. KG
Manahan Todd #E.
St. Onge Steward Johnston & Reens LLC
LandOfFree
Material for differently modifying the optical properties of... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Material for differently modifying the optical properties of..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Material for differently modifying the optical properties of... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3249248