Diamonds In The Rough

UCLA researchers have discovered that diamonds on a much, much smaller scale than those used in jewelry could be used to promote bone growth and the durability of dental implants. Nanodiamonds, which are created as byproducts of conventional mining and refining operations, are approximately four to five nanometers in diameter and are shaped like tiny soccer balls. Scientists from the UCLA School of Dentistry, the UCLA Department of Bioengineering and Northwestern University, along with collaborators at the NanoCarbon Research Institute in Japan, may have found a way to use them to improve bone growth and combat osteonecrosis, a potentially debilitating disease in which bones break down due to reduced blood flow. When osteonecrosis affects the jaw, it can prevent people from eating and speaking; when it occurs near joints, it can restrict or preclude movement. Bone loss also occurs next to implants such as prosthetic joints or teeth, which leads to the implants becoming loose - or failing. Implant failures necessitate additional procedures, which can be painful and expensive, and can jeopardize the function the patient had gained with an implant. These challenges are exacerbated when the disease occurs in the mouth, where there is a limited supply of local bone that can be used to secure the prosthetic tooth, a key consideration for both functional and aesthetic reasons. The study, led by Dr. Dean Ho, professor of oral biology and medicine and co-director of the Jane and Jerry Weintraub Center for Reconstructive Biotechnology at the UCLA School of Dentistry, appears online in the peer-reviewed Journal of Dental Research. During bone repair operations, which are typically costly and time-consuming, doctors insert a sponge through invasive surgery to locally administer proteins that promote bone growth, such as bone morphogenic protein. Ho's team discovered that using nanodiamonds to deliver these proteins has the potential to be more effective than the conventional approaches. The study found that nanodiamonds, which are invisible to the human eye, bind rapidly to both bone morphogenetic protein and fibroblast growth factor, demonstrating that the proteins can be simultaneously delivered using one vehicle. The unique surface of the diamonds allows the proteins to be delivered more slowly, which may allow the affected area to be treated for a longer period of time. Furthermore, the nanodiamonds can be administered non-invasively, such as by an injection or an oral rinse. "We've conducted several comprehensive studies, in both cells and animal models, looking at the safety of the nanodiamond particles," said Laura Moore, the first author of the study and an M.D.-Ph.D. student at Northwestern University under the mentorship of Dr. Ho. "Initial studies indicate that they are well tolerated, which further increases their potential in dental and bone repair applications." "Nanodiamonds are versatile platforms," said Ho, who is also professor of bioengineering and a member of the Jonsson Comprehensive Cancer Center and the California NanoSystems Institute. "Because they are useful for delivering such a broad range of therapies, nanodiamonds have the potential to impact several other facets of oral, maxillofacial and orthopedic surgery, as well as regenerative medicine." Ho's team previously showed that nanodiamonds in preclinical models were effective at treating multiple forms of cancer. Because osteonecrosis can be a side effect of chemotherapy, the group decided to examine whether nanodiamonds might help treat the bone loss as well. Results from the new study could open the door for this versatile material to be used to address multiple challenges in drug delivery, regenerative medicine and other fields. "This discovery serves as a foundation for the future of nanotechnology in dentistry, orthopedics and other domains in medicine," said Dr. No-Hee Park, dean of the School of Dentistry. "Dr. Ho and his team have demonstrated the enormous potential of the nanodiamonds toward improving patient care. He is a pioneer in his field."

Arthritis and Your Gums ?

Does gum disease indicate future joint problems? Although researchers and clinicians have long known about an association between two prevalent chronic inflammatory diseases - periodontal disease and rheumatoid arthritis (RA) - the microbiological mechanisms have remained unclear. In an article published in PLoS Pathogens, University of Louisville School of Dentistry Oral Health and Systemic Diseases group researcher Jan Potempa, PhD, DSc, and an international team of scientists from the European Union's Gums and Joints project have uncovered how the bacterium responsible for periodontal disease, Porphyromonas gingivalis worsens RA by leading to earlier onset, faster progression and greater severity of the disease, including increased bone and cartilage destruction. The scientists found that P. gingivalis produces a unique enzyme, peptidylarginine deiminanse (PAD) which then enhances collagen-induced arthritis (CIA), a form of arthritis similar to RA produced in the lab. PAD changes residues of certain proteins into citrulline, and the body recognizes citullinated proteins as intruders, leading to an immune attack. In RA patients, the subsequent result is chronic inflammation responsible for bone and cartilage destruction within the joints. Potempa and his team studied another oral bacterium, Prevotella intermedia for the same affect, but learned it did not produce PAD, and did not affect CIA. "Taken together, our results suggest that bacterial PAD may constitute the mechanistic link between P. gingivalis periodontal infection and rheumatoid arthritis, but this ground-breaking conclusion will need to be verified with further research," he said. Potempa said he is hopeful these findings will shed new light on the treatment and prevention of RA. Studies indicate that compared to the general population, people with periodontal disease have an increased prevalence of RA and, periodontal disease is at least two times more prevalent in RA patients. Other research has shown that a P. gingivalis infection in the mouth will precede RA, and the bacterium is the likely culprit for onset and continuation of the autoimmune inflammatory responses that occur in the disease.

Pregnancy and Dental Health

When a woman becomes pregnant, she knows it is important to maintain a healthy lifestyle to ensure both the health of herself and the health of her baby. New clinical recommendations from the American Academy of Periodontology (AAP) and the Eurpean Federation of Periodontology (EFP) urge pregnant women to maintain periodontal health as well. Research has indicated that women with periodontal disease may be at risk of adverse pregnancy outcomes, such giving birth to a pre-term or low-birth weight baby, reports the AAP and EFP. Periodontal disease is a chronic, bacteria-induced, inflammatory condition that attacks the gum tissue and in more severe cases, the bone supporting the teeth. If left untreated, periodontal disease, also known as gum disease, can lead to tooth loss and has been associated with other systemic diseases, such as diabetes and cardiovascular disease. "Tenderness, redness, or swollen gums are a few indications of periodontonal disease," warns Dr. Nancy L. Newhouse, DDS, MS, President of the AAP and a practicing periodontist in Independence, Missouri. "Other symptoms include gums that bleed with toothbrushing or eating, gums that are pulling away from the teeth, bad breath, and loose teeth. These signs, especially during pregnancy, should not be ignored and may require treatment from a dental professional." Several research studies have suggested that women with periodontal disease may be more likely to deliver babies prematurely or with low-birth weight than mothers with healthy gums. According to the Center for Disease Control and Prevention (CDC), babies with a birth weight of less than 5.5 pounds may be at risk of long-term health problems such as delayed motor skills, social growth, or learning disabilities. Similar complications are true for babies born at least three weeks earlier than its due date. Other issues associated with pre-term birth include respiratory problems, vision and hearing loss, or feeding and digestive problems. The medical and dental communities concur that maintaining periodontal health is an important part of a healthy pregnancy. The clinical recommendations released by the AAP and the EFP state that non-surgical periodontal therapy is safe for pregnant women, and can result in improved periodontal health. Published concurrently in the Journal of Periodontology and Journal of Clinical Periodontology, the report provides guidelines for both dental and medical professionals to use in diagnosing and treating periodontal disease in pregnant women. In addition, the American College of Obstetricians and Gynecologists recently released a statement encouraging pregnant women to sustain their oral health and recommended regular dental cleanings during pregnancy. "Routine brushing and flossing, and seeing a periodontist, dentist, or dental hygienist for a comprehensive periodontal evaluation during pregnancy may decrease the chance of adverse pregnancy complications," says Dr. Newhouse. "It is important for expectant mothers to monitor their periodontal health and to have a conversation with their periodontist or dentist about the most appropriate care. By maintaining your periodontal health, you are not only supporting your overall health, but also helping to ensure a safe pregnancy and a healthy baby," says Dr. Newhouse.