Surgery – Instruments – Light application
Patent
1994-10-25
1997-03-18
Sykes, Angela D.
Surgery
Instruments
Light application
433216, 433229, A61B 1732
Patent
active
056117930
DESCRIPTION:
BRIEF SUMMARY
The present invention relates to the use of photosensitising compounds and laser irradiation to kill the microbes involved in a number of oral diseases including inflammatory periodontal disease and caries or in wound infections and in disinfecting or sterilising wounds and other lesions in the oral cavity.
Inflammatory periodontal diseases are the most prevalent diseases of humans and the advanced form, chronic periodontitis, is the major cause of tooth loss in adults. Current methods of treating chronic periodontitis involve removal of subgingival plaque in order to eliminate the causative organisms; this is often supplemented by antimicrobial chemotherapy. Mechanical removal of plaque is never fully successful and there are many disadvantages in the long-term use of antimicrobial agents such as chlorhexidine and tetracycline, notably the development of resistance rendering the agents clinically ineffective and difficulties arising from disturbance of the oral microflora.
There is also a need to destroy microorganisms in drilled-out carious cavities prior to conventional filling and during other forms of dental surgery.
Another situation requiring destruction of microbes in the oral cavity is in the case of oral candidiasis of AIDS patients, immunocompromised individuals and patients with denture stomatitis where conventional treatment by chemotherapy is only poorly effective.
The present inventors have developed a method for destroying disease-related microbes in the oral cavity.
Accordingly, the present invention provides a method for disinfecting or sterilising tissues in the oral cavity or a wound or lesion in the oral cavity, which method comprises applying a photosensitising compound to the tissues, wound or lesion and irradiating the tissues wound or lesion with laser light at a wavelength absorbed by the photosensitising compound.
The invention also provides the use of a photosensitising compound in the manufacture of a medicament for use in disinfecting or sterilising tissues of the oral cavity or a wound or lesion in the oral cavity by compound such that any disease-related microbes in the tissues, wound or lesion take up the photosensitising compound and wavelength absorbed by the photosensitising compound.
The wound or lesion treated may be any surgical or trauma-induced wound, a lesion caused by a disease-related microbe, or a wound or lesion infected with such a microbe. The treatment may be applied to disinfect or sterilise a wound or lesion as a routine precaution against infection or as a specific treatment of an already diagnosed infection of a wound or lesion.
In one aspect the present invention provides a method for destroying disease-related microbes in the oral cavity which method comprises applying a photosensitising compound to the microbes and irradiating the microbes with laser light at a wavelength absorbed by the photosensitising compound.
The invention further provides the use of a photosensitising compound in the manufacture of a medicament for use in destroying disease-related microbes in the oral cavity by the microbes take up the photosensitising compound and the photosensitising compound.
In preferred aspects of the invention the treatment with photosensitising compound and laser irradiation are applied to order to treat chronic periodontitis; tooth and gingiva (gingival crevice or gingival margin) in order to treat or prevent inflammatory periodontal diseases including chronic periodontitis, gingivitis and the like; filling; treat or prevent dental caries. other dental surgical procedures and patients or those with denture stomatitis.
Photosensitising compounds for use in accordance with the present invention are generally non-toxic to the target microbes at concentrations envisaged in accordance with the invention and to the tissues surrounding the wound or lesion. However there is no particular requirement that the photosensitisers should be non-toxic to the microbes. Moreover, since exposure of the surrounding tissues of the oral cavity to the photosensitiser will ge
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Harvey Wilson
Wilson Michael
Harris-Ogugua Sonya
Institute of Dental Surgery
Sykes Angela D.
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