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NEW TARGET IN FIGHT AGAINST OSTEOPOROSIS, PERIODONTITIS DISCOVERED
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NEW TARGET IN FIGHT AGAINST OSTEOPOROSIS, PERIODONTITIS DISCOVERED
potential new focus of treatment for osteoporosis, periodontitis and similar diseases has been identified, say researchers in the May 17 online edition of the journal Nature Medicine. In the article, researchers at the University of California Los Angeles (UCLA), University of California San Diego and the University of Michigan suggest that inhibiting nuclear factorκB (NF-κB)—a master protein that controls genes associated with inflammation and immunity and plays a role in osteoporosis and periodontitis by disrupting the healthy balance of bone destruction and formation—can prevent disabling bone loss by maintaining bone formation. Principal investigator Dr. Cun-Yu Wang, No-Hee Park Endowed Chair, Division of Oral Biology and Medicine, UCLA School of Dentistry, and colleagues conducted in vitro and in vivo studies to explore ways to restore and promote net bone accumulation. “Most studies focus on the part that NF-κB plays in the regulation of osteoclasts—boneresorbing cells,” said Dr. Wang. “For the past five years, we looked closely at the effect of NF-κB on osteoblasts—boneforming cells. We knew that NF-κB promoted resorption. What we discovered in our in vitro and in vivo studies is that this protein also inhibits new bone formation, giving us a fuller picture of its role in inflammation and immune responses.” Many available treatments work to prevent further bone
A
836
JADA, Vol. 140
http://jada.ada.org
loss but are not able to increase bone mass. Dr. Wang and colleagues’ research results support the idea that a new drug that prevents the action of NF-κB in cells may be a major therapeutic advance. As a next step, Wang and his research team are planning to test small molecules that inhibit the specific bone-resorption and bone-inhibition actions of NF-κB in osteoporosis and periodontitis. The study was supported by grants from the National Institute of Dental and Craniofacial Research and the National Institute of Diabetes and Digestive and Kidney Diseases. Compiled by Amy E. Lund, senior editor.
SELF-LIGATING ORTHODONTIC BRACKETS ASSOCIATED WITH FEWER PLAQUE BACTERIA
he majority of patients with self-ligating orthodontic brackets retain fewer bacteria in plaque than do patients with elastomeric orthodontic brackets, according to a study published in the April issue of American Journal of Orthodontics & Dentofacial Orthopedics. Acid-producing bacteria that surround orthodontic appliances are a common problem. Such bacteria can lead to tooth enamel breakdown and potential discoloration of the tooth surface that can persist for many years. Researchers at the Oregon Health & Science University’s School of Dentistry, Portland, examined 14 patients aged 11 to 17 years who wore self-ligating and elastomeric orthodontic brackets on opposing sides of the mouth. They conducted the examinations one week and five weeks after bonding.
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The investigators evaluated the numbers of oral bacteria in plaque surrounding the brackets at both appointments, as well as at a prebonding appointment. They used conventional plating techniques enumerating bacterial colony number and the adenosine triphosphate (ATP)– driven bioluminescence technique. More bacteria, including oral streptococci, were retained in plaque at tooth surfaces in patients with elastomeric brackets at both the one- and five-week postbonding appointments. Bacterial levels were particularly high at the one-week examination. The researchers also observed higher ATP-driven bioluminescence levels in plaque surrounding the elastomeric orthodontic appliances. “We were surprised that the manner of ligation promoted differences in the levels of plaque bacteria surrounding the bonded tooth surfaces,” said Curt Machida, PhD, professor of integrative biosciences and principal investigator. “Our results suggest that the use of the self-ligating appliances promote reduced retention of plaque bacteria on tooth surfaces sur-
JADAPreview COMING IN AUGUST
dThe validity of pulpal testing dImproved denture retention in patients with retracted tongues dA multilocular radiolucency of the mandible Look for this and more in the August issue of JADA.
July 2009
Copyright © 2009 American Dental Association. All rights reserved. Reprinted by permission.
E
W
S
NEW TARGET IN FIGHT AGAINST OSTEOPOROSIS, PERIODONTITIS DISCOVERED
potential new focus of treatment for osteoporosis, periodontitis and similar diseases has been identified, say researchers in the May 17 online edition of the journal Nature Medicine. In the article, researchers at the University of California Los Angeles (UCLA), University of California San Diego and the University of Michigan suggest that inhibiting nuclear factorκB (NF-κB)—a master protein that controls genes associated with inflammation and immunity and plays a role in osteoporosis and periodontitis by disrupting the healthy balance of bone destruction and formation—can prevent disabling bone loss by maintaining bone formation. Principal investigator Dr. Cun-Yu Wang, No-Hee Park Endowed Chair, Division of Oral Biology and Medicine, UCLA School of Dentistry, and colleagues conducted in vitro and in vivo studies to explore ways to restore and promote net bone accumulation. “Most studies focus on the part that NF-κB plays in the regulation of osteoclasts—boneresorbing cells,” said Dr. Wang. “For the past five years, we looked closely at the effect of NF-κB on osteoblasts—boneforming cells. We knew that NF-κB promoted resorption. What we discovered in our in vitro and in vivo studies is that this protein also inhibits new bone formation, giving us a fuller picture of its role in inflammation and immune responses.” Many available treatments work to prevent further bone
A
836
JADA, Vol. 140
http://jada.ada.org
loss but are not able to increase bone mass. Dr. Wang and colleagues’ research results support the idea that a new drug that prevents the action of NF-κB in cells may be a major therapeutic advance. As a next step, Wang and his research team are planning to test small molecules that inhibit the specific bone-resorption and bone-inhibition actions of NF-κB in osteoporosis and periodontitis. The study was supported by grants from the National Institute of Dental and Craniofacial Research and the National Institute of Diabetes and Digestive and Kidney Diseases. Compiled by Amy E. Lund, senior editor.
SELF-LIGATING ORTHODONTIC BRACKETS ASSOCIATED WITH FEWER PLAQUE BACTERIA
he majority of patients with self-ligating orthodontic brackets retain fewer bacteria in plaque than do patients with elastomeric orthodontic brackets, according to a study published in the April issue of American Journal of Orthodontics & Dentofacial Orthopedics. Acid-producing bacteria that surround orthodontic appliances are a common problem. Such bacteria can lead to tooth enamel breakdown and potential discoloration of the tooth surface that can persist for many years. Researchers at the Oregon Health & Science University’s School of Dentistry, Portland, examined 14 patients aged 11 to 17 years who wore self-ligating and elastomeric orthodontic brackets on opposing sides of the mouth. They conducted the examinations one week and five weeks after bonding.
T
The investigators evaluated the numbers of oral bacteria in plaque surrounding the brackets at both appointments, as well as at a prebonding appointment. They used conventional plating techniques enumerating bacterial colony number and the adenosine triphosphate (ATP)– driven bioluminescence technique. More bacteria, including oral streptococci, were retained in plaque at tooth surfaces in patients with elastomeric brackets at both the one- and five-week postbonding appointments. Bacterial levels were particularly high at the one-week examination. The researchers also observed higher ATP-driven bioluminescence levels in plaque surrounding the elastomeric orthodontic appliances. “We were surprised that the manner of ligation promoted differences in the levels of plaque bacteria surrounding the bonded tooth surfaces,” said Curt Machida, PhD, professor of integrative biosciences and principal investigator. “Our results suggest that the use of the self-ligating appliances promote reduced retention of plaque bacteria on tooth surfaces sur-
JADAPreview COMING IN AUGUST
dThe validity of pulpal testing dImproved denture retention in patients with retracted tongues dA multilocular radiolucency of the mandible Look for this and more in the August issue of JADA.
July 2009
Copyright © 2009 American Dental Association. All rights reserved. Reprinted by permission.