2012 AADR William Clark Fellowship
Sponsored by the American Association for Dental Research and P&G Professional Oral Health, Crest Oral-B
Women are at risk for osteoporosis when the ovaries greatly reduce estrogen production after menopause. Since the Women’s Health Initiative called hormone replacement therapy into question in 2005, bisphosphonate therapy has been widely prescribed for prevention and treatment of postmenopausal osteoporosis. Questions about drug safety surfaced when case reports documenting osteonecrosis of the jaws (ONJ) began to emerge (Marx 2003, Ruggiero 2004). Also around 2005, several more well-controlled investigations documented that bisphosphonates, through their effect on osteoclasts, could improve the periodontium (Rocha 2004, Lane 2005, Palomo 2005, Jeffcoat 2007). The role of pro-inflammatory cytokines IL-1, IL-6 and TNF-alpha, involved in osteoclast activation, is not well understood in bisphosphonate therapy users. On one hand, the therapy is shown to reduce osteoclastic bone resorption in the jaws and in the skeleton, on the other hand, some ONJ studies show an increase in cytokine response and bone loss (Scheller 2011).
Bacterial biofilms have been suggested as a potential etiologic agent in the pathogenesis of ONJ (Sedghizedeh 2009). A difference is reported between the quantities of plaque bacterial biofilm between postmenopausal women using long-term bisphosphonate for prevention and treatment of osteoporosis and postmenopausal women not using such medication (Palomo 2011); however there are no data on the nature of the periodontal microbiota between the two groups. Whether or not the specific bacteria play a role in the effects to the periodontal tissues is unknown.
The aim of this project is to compare pro-inflammatory cytokine response and microbiota between postmenopausal women who use bisphosphonate therapy for prevention and treatment of osteoporosis with those who do not. The aim of the Clark Award is to gain experience the premier, state of the art, research facility focusing on “checkerboard” DNA-DNA hybridization technique to identify this microbiota and multiplex ELIZA technique to compare cytokine response.