- Email: [email protected]
SCIENTISTS TISSUE ENGINEER MANDIBULAR CONDYLES
N
W
S
CHANGE OF ADDRESS FOR JADA MANUSCRIPT SUBMISSION, REVIEW
SMOKERS SHOULD QUIT BEFORE DENTAL PROCEDURES
mokers may want to quit before undergoing oral surgery, say researchers in the October issue of the Journal of Periodontology. Swedish researchers investigated the relationship between tobacco smoking and the inflammatory response in smokers who consumed 10 to 20 cigarettes a day. They studied 15 smokers and 15 nonsmokers with moderate-to-severe periodontitis who were undergoing oral surgery. They conducted clinical examinations and collected gingival crevicular fluid, or GCF, before the subjects underwent surgery and at one and five weeks after treatment. After analyzing the substances in the GCF, researchers found that the body’s defense mechanism was weakened in smokers, whereas the defense mechanism in nonsmokers promoted a more favorable healing response. They interpreted these findings as smoking possibly interfering with the treatment response. They said that it also might explain the clinical evidence of inferior treatment outcomes in smokers.
S
SCIENTISTS TISSUE ENGINEER MANDIBULAR CONDYLES
cientists have created mandibular condyles from rat adult stem cells that are the precise three-dimensional shape of the human joint, according to a study published in the December issue of the Journal of Dental Research. Studies in tissue engineering—using the body’s own biological materials to repair, regenerate and replace dam-
S
E
ffective Jan. 1, the manuscript review process for The Journal of the American Dental Association is being handled through JADA Editor Marjorie K. Jeffcoat’s office at the University of Pennsylvania School of Dental Medicine. All questions about manuscript submission and review should be directed to this address: The Journal of the American Dental Association Editorial Office University of Pennsylvania School of Dental Medicine The Robert Schattner Center 240 S. 40th St., Room E6 Philadelphia, Pa. 19104-6030 Phone: 1-215-746-0224 Fax: 1-215-898-5474 E-mail: “[email protected]” JADA’s Guidelines for Authors, including this new address, are available online at “www.ada.org/goto/authorguidelines”.
E
aged organs and tissues, including bone and cartilage—have focused on the initial step of repairing a small area of damaged tissue. Two years ago, Dr. Jeremy Mao, study co-author and a scientist at the University of Illinois at Chicago, and colleagues took the next step and engineered a mandibular condyle. They isolated adult mesenchymal stem cells from rat bone marrow, and then treated the cells in the laboratory to differentiate them into either bone-producing or cartilage-producing cells called osteoblasts and chondrocytes, respectively. Researchers then seeded the differentiated cells into a hydrogel polymer solution in stratified layers. The seeded solution was molded into the shape of a human mandibular condyle. Researchers implanted three small molded structures just below the skin of immunodeficient mice. At eight weeks, researchers harvested the three tissueengineered condyles from the
mice. They found that the implants had formed on their own into “firm” structures that retained the precise shape and three-dimensional structure of the molded human mandibular condyle. They also found that the osteoblasts had produced bone, and they identified “sparse chondrocyte-like cells within abundant extracellular matrix” that expressed certain proteins characteristic of cartilage. Stressing that their findings are preliminary, researchers said they are hopeful because they produced the structures from a single population of stem cells and prompted them to form two distinct layers of bone and cartilage. They plan to attempt to enhance the biological and mechanical properties of the tissue-engineered condyles. Dr. Mao, however, said that these results are just the start of a much bigger scientific challenge. “It is no small task to recapitulate what nature does perfectly during development,” he
JADA, Vol. 135, January 2004 Copyright ©2004 American Dental Association. All rights reserved.
27
W
S
CHANGE OF ADDRESS FOR JADA MANUSCRIPT SUBMISSION, REVIEW
SMOKERS SHOULD QUIT BEFORE DENTAL PROCEDURES
mokers may want to quit before undergoing oral surgery, say researchers in the October issue of the Journal of Periodontology. Swedish researchers investigated the relationship between tobacco smoking and the inflammatory response in smokers who consumed 10 to 20 cigarettes a day. They studied 15 smokers and 15 nonsmokers with moderate-to-severe periodontitis who were undergoing oral surgery. They conducted clinical examinations and collected gingival crevicular fluid, or GCF, before the subjects underwent surgery and at one and five weeks after treatment. After analyzing the substances in the GCF, researchers found that the body’s defense mechanism was weakened in smokers, whereas the defense mechanism in nonsmokers promoted a more favorable healing response. They interpreted these findings as smoking possibly interfering with the treatment response. They said that it also might explain the clinical evidence of inferior treatment outcomes in smokers.
S
SCIENTISTS TISSUE ENGINEER MANDIBULAR CONDYLES
cientists have created mandibular condyles from rat adult stem cells that are the precise three-dimensional shape of the human joint, according to a study published in the December issue of the Journal of Dental Research. Studies in tissue engineering—using the body’s own biological materials to repair, regenerate and replace dam-
S
E
ffective Jan. 1, the manuscript review process for The Journal of the American Dental Association is being handled through JADA Editor Marjorie K. Jeffcoat’s office at the University of Pennsylvania School of Dental Medicine. All questions about manuscript submission and review should be directed to this address: The Journal of the American Dental Association Editorial Office University of Pennsylvania School of Dental Medicine The Robert Schattner Center 240 S. 40th St., Room E6 Philadelphia, Pa. 19104-6030 Phone: 1-215-746-0224 Fax: 1-215-898-5474 E-mail: “[email protected]” JADA’s Guidelines for Authors, including this new address, are available online at “www.ada.org/goto/authorguidelines”.
E
aged organs and tissues, including bone and cartilage—have focused on the initial step of repairing a small area of damaged tissue. Two years ago, Dr. Jeremy Mao, study co-author and a scientist at the University of Illinois at Chicago, and colleagues took the next step and engineered a mandibular condyle. They isolated adult mesenchymal stem cells from rat bone marrow, and then treated the cells in the laboratory to differentiate them into either bone-producing or cartilage-producing cells called osteoblasts and chondrocytes, respectively. Researchers then seeded the differentiated cells into a hydrogel polymer solution in stratified layers. The seeded solution was molded into the shape of a human mandibular condyle. Researchers implanted three small molded structures just below the skin of immunodeficient mice. At eight weeks, researchers harvested the three tissueengineered condyles from the
mice. They found that the implants had formed on their own into “firm” structures that retained the precise shape and three-dimensional structure of the molded human mandibular condyle. They also found that the osteoblasts had produced bone, and they identified “sparse chondrocyte-like cells within abundant extracellular matrix” that expressed certain proteins characteristic of cartilage. Stressing that their findings are preliminary, researchers said they are hopeful because they produced the structures from a single population of stem cells and prompted them to form two distinct layers of bone and cartilage. They plan to attempt to enhance the biological and mechanical properties of the tissue-engineered condyles. Dr. Mao, however, said that these results are just the start of a much bigger scientific challenge. “It is no small task to recapitulate what nature does perfectly during development,” he
JADA, Vol. 135, January 2004 Copyright ©2004 American Dental Association. All rights reserved.
27