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Smestad, Thomas L.; Prows, Daniel; Chu, George H.; Hendericks, Diana M.; Brown, Debera; |
Gamma irradiation of collagen/mineral mixtures

The present invention is a method for treating bony defects. The method involves contacting the bony defect with a formable composition and allowing the formable composition to solidify. The formable composition is comprised of 2-40% of reconstituted fibrillar atelopeptide collagen and 60-98% calcium phosphate mineral by weight exclusive of moisture. After the formable composition is placed in intimate contact with the bony defect, it is allowed to solidify until it acquires an additional characteristic selected from the group consisting of a compressive modulus of at 10 N/cm.sup.2 or a tensile strength of at least 1 N/cm.sup.2. The method can be used to repair a variety of bony defects such as bone non-union, fresh fractures, periodontal bony pockets, tooth extraction sockets and jaw cysts. Further, the composition can be used to augment an alveolar ridge.


We claim:
1. A method for treating a bony defect, comprising:
contacting the bony defect with a formable composition comprising 2-40% reconstituted fibrillar atelopeptide collagen and 60-98% calcium phosphate mineral by weight exclusive of moisture, which composition has a sterility assurance factor of at least as low as 10.sup.-6 ;
allowing the formable composition to solidify until the composition has an additional characteristic selected from the group consisting of a compressive modulus of at least 10 N/cm.sup.2 or a tensile strength of at least 1 N/cm.sup.2.
2. A method for treating a bony defect, comprising the steps of:
contacting the bony defect with a formable mixture containing 2-40% reconstituted fibrillar atelopeptide collagen and 60-98% calcium phosphate mineral by weight exclusive of moisture, which composition has a sterility assurance factor of at least as low as 10.sup.-6 ; and
allowing the formable composition to solidify until the mixture acquires an additional characteristic selected from the group consisting of a compressive modulus in the range of 25-45 N/cm.sup.2 and a tensile strength of about 3-12 N/cm.sup.2.
3. The method as claimed in claim 1, wherein the bony defect is a bony defect selected from the group consisting of bone nonunion, fresh fracture, periodontal bony pocket, tooth extraction socket, and jaw cyst.
4. The method as claimed in claim 1, wherein the composition is contacted with an alveolar ridge in order to augment the alveolar ridge.
5. The method as claimed in claim 1, wherein the composition is further comprised of glutaraldehyde in an amount in the range of 0.001-1.0% by weight.
6. The method as claimed in claim 1, wherein the composition has a compressive modulus in the range of 10-60 N/cm.sup.2.
7. The method as claimed in claim 1, wherein the composition has a compressive modulus in the range of 25-45 N/cm.sup.2.
8. The method as claimed in claim 1, wherein the gamma radiation is applied in an amount in the range of 0.5-4 Mrad.
9. The method as claimed in claim 8, wherein the gamma radiation is applied in an amount in the range of 1-3 Mrad.
10. The method as claimed in claim 9, wherein the gamma radiation is applied in an amount in the range of 2.5to about 3 Mrad.
11. The method as claimed in claim 1, wherein the gamma radiation is applied from a gamma-emitting source selected from the group consisting of .sup.131 I, .sup.137 Cs and .sup.60 Co.
12. The method as claimed in claim 1, wherein the composition is dried prior to irradiation so as to have a moisture content of less than 1% and then heated for 4-24 hours at about 60-90.degree. C. at a relative humidity in the range of about 20-80 %.
13. The method as claimed in claim 12, wherein the composition is so as to have a moisture content in the range of 0.5-1% prior to irradiation and then heated for 4-24 hours at a temperature in the range of 70-80.degree. C. at a relative humidity in the range of about 50-60 % relative humidity.
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