Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Processes of preparing a desired or intentional composition...
Patent
1993-09-03
1996-06-11
Michl, Paul R.
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Processes of preparing a desired or intentional composition...
523115, 524308, 524310, 524311, 525410, 525415, 525461, 433215, 4332011, 433229, 424423, 424426, 623 11, 623 12, A61F 200, C08K 510, C08G 6391
Patent
active
055256465
DESCRIPTION:
BRIEF SUMMARY
The present invention relates to a bioresorbable material and an article of manufacture made of such material for medical use to be implanted into a living organism, e.g. for selective influences on the healing process by guiding tissue growth, e.g. in healing after periodontal surgery (guided periodontal tissue regeneration) and in connection with regeneration of other hard and soft intra- and extra-oral tissues, the element preferably being in the form of an element, layer(s), foil, sheet or film, but the element may also be formed as a filament or tube.
During the last decades biodegradable materials have been increasingly widely used in the medical field. Initially collagen was introduced which, however, causes problems due to the fact that it has an irregular degradation time and may cause inflammatory and in some cases allergic reactions. Since the beginning of 1970 new materials with improved characteristics, in terms of biodegradation time and biocompatibility, have been developed, primarily polyglycolic acid (PGA) and polylactic acid (PLA). PGA and PLA have been successful commercially and are used today for medical applications, e.g. as sutures and orthopedic pins, applications where above all material strength is required.
The tissue regeneration applications mentioned in the introduction require another set of characteristics of the elements being used (aside from biodegradability and biocompatibility), primarily malleability at the time of surgery, and dimensional stability of the material during the healing phase after being implanted in vivo.
Malleability as used herein is a led-like plasticity, i.e. the material does not immediately or over a short period regain the shape that it had before it was reshaped, which means that the material has no or very little memory. Malleability according to this definition is important at the time of surgery so that the material can be located along the tissue to be covered and the shape of the material can be adapted to the shape of the region to be covered, often in a three-dimensional fashion. This characteristic facilitates the surgical procedure. Moreover, absence of a memory of the element assures that the adjacent tissue is exposed to a minimum of pressure.
Dimensional stability is important so that an appropriate design or shape imparted to the material can be maintained over a certain period of time which often can be defined as the period which is critical for the healing process. Dimensional stability reduces the tendency of the material to swell thereby eliminating a possible second source of pressure to the tissues adjacent to the implanted element.
WO 90/7308 describes several embodiments of an element for guiding tissue growth in regeneration of supporting tissues of teeth and dental implants, in healing after periapical operations, and in connection with filling of bone cavities caused by cysts and malformations, and diastases caused by bone fractures. In said application polymers are said to be suitable materials for the biodegradable element, and among others polylactide (PLA) is mentioned.
PLA can be pliable if woven or knitted but is hardly malleable. It is moreover very difficult if at all possible to make structures other than those inherent in the weaving or knitting techniques. By using other known manufacturing technique, such as compression molding, injection molding, or calendering among others, it is in fact possible to make small structures in PLA that are stable over a certain period, but such structures would not be malleable and would fracture easily due to the physical state of the PLA polymer itself. Polytrimethylene carbonate is a bioresorbable material which is soft but elastic rather than malleable, i.e. it will spring back when folded. Due to a low glass transition temperature this material has poor dimensional stability, and moreover, the bioresorption thereof extends over a long time, probably no less than two years, which could be a disadvantage, e.g. in the periodontal application, and has specific negative consequ
REFERENCES:
patent: 5061281 (1991-10-01), Mares et al.
Gottlow Jan
Lundgren Dan
Mathisen Torbjorn
DeWitt LaVonda R.
Michl Paul R.
LandOfFree
Bioresorbable material and an article of manufacture made of suc does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Bioresorbable material and an article of manufacture made of suc, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Bioresorbable material and an article of manufacture made of suc will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-352023