Scientists Develop Self-Healing Dental Enamel By Mimicking Epidermal Layers

MedicalResearch.com Interview with:
“chipped tooth” by bagaball is licensed under CC BY 2.0Dr. Ming Yang

Key Laboratory of Microsystems and Microstructures Manufacturing,
Harbin Institute of Technology,
Harbin, China 

MedicalResearch.com: What is the background for this study? What are the main findings?

Response: Self-healing materials and coatings are smart solutions to environmental and energy problems. There are heavy demands for these materials in many productions such as consumer electronics, the automotive industry and healthcare.

Current coatings that can self-heal are typically soft. This means they are not as anti-scratch as rigid surfaces and the benefit of the ability to repair themselves could be overwhelmed by their limited robustness vulnerable to normal mechanical contact. It would be very useful to have a self-healing coating with a hardness that can be comparable or even outperform rigid coatings. This is normally difficult because mechanical hardness and self-healing are two conflicting properties with the opposite dependence on polymer dynamics. One good example in this context is many soft tissues can self-heal, but a notable exception is tooth enamel, which is the hardest part in our body but has no way to recover after decay. A new design will be needed to circumvent the fundamental limitation.

We find that by mimicking the structure of epidermis, it is possible to combine two contradictory properties into an artificial coating, namely, self-healing ability and high hardness. The success relies on the placement of a hard layer containing graphene oxide on top of a soft sublayer with a seamless interface for interlayer diffusion. This allows a similar healing mechanism as that in skin, but the coating is not soft and has a hardness that even approaches tooth enamel.  Continue reading

Failure of Dental Fillings Is At Least Partially Genetically Determined

MedicalResearch.com Interview with:
“Dental Mold_002” by Ano Lobb is licensed under CC BY 2.0
Alexandre R. Vieira, DDS. MS, PhD
Professor, Director of Clinical Research,  Director of Student Research
Department of Oral Biology
Center for Craniofacial and Dental Genetics
Department of Pediatric Dentistry
School of Dental Medicine
Department of Human Genetics
Graduate School of Public Health
Clinical and Translational Sciences Institute
University of Pittsburgh 

MedicalResearch.com: What is the background for this study? What are the main findings?

Response: One aspect is the dilemma between continuing to use dental amalgams and the perception that composite resins are not as durable.

We show that composite resin restorations can perform similarly to dental amalgams for the first 5 years. But the most remarkable is that composite resin failures may be related to certain individual risk factors, such as genetic variation.

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Antibiotics Prescribed By Dentists May Contribute To C.diff Infections

MedicalResearch.com Interview with:

Stacy Holzbauer, DVM, MPH, DACVPM CDC Career Epidemiology Field Officer (CEFO) Commander, USPHS Minnesota Department of Health St. Paul, MN

Dr. Holzbauer

Stacy Holzbauer, DVM, MPH, DACVPM
CDC Career Epidemiology Field Officer (CEFO)
Commander, USPHS
Minnesota Department of Health
St. Paul, MN

MedicalResearch.com: What is the background for this study?

  • Antibiotics are not harmless drugs—Clostridium difficile infection, which can sometimes cause a deadly diarrhea, is a complication of antibiotic use and can occur after even one dose of an antibiotic.
  • The Minnesota Department of Health (MDH) is part of the larger Centers for Disease Control and Prevention (CDC) Emerging Infections Program (EIP). The healthcare-associated infection component of CDC’s EIP engages a network of state health departments and their academic medical center partners to help answer critical questions about emerging HAI threats including Clostridium difficile also known as “C. diff.”
  • In Minnesota, the majority of C. diff infections occur outside the hospital and are driven by antibiotic use in community or outpatient settings. In addition to routine surveillance data, we interview patients with C. diff who were not hospitalized prior to their infection to identify potential risks for developing C. diff infection, including identifying antibiotics received outside of routine healthcare settings.
  • Dentists prescribe approximately 10% of the antibiotics in outpatient settings, which was over 24 million prescriptions in 2013. When asked about their prescribing practices in a 2015 survey with the Minnesota Dental Association, 36% of dentists surveyed prescribed antibiotics for dental conditions that are generally not recommended to receive antibiotics according to American Dental Association (ADA) guidelines.

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Periodontal Disease is Associated with Higher Risk of Cancer in Postmenopausal Women

MedicalResearch.com Interview with:

Jean Wactawski-Wende, PhD Dean, SUNY Distinguished Professor Professor, Department of Epidemiology and Environmental Health School of Public Health and Health Professions University of Buffalo

Dr. Wactawski-Wende

Jean Wactawski-Wende, PhD
Dean, SUNY Distinguished Professor
Professor, Department of Epidemiology and Environmental Health
School of Public Health and Health Professions
University of Buffalo

MedicalResearch.com: What is the background for this study? What are the main findings?

Response: There has been a growing interest in the role of periodontal disease in system chronic diseases, including cancer. We explored the association of periodontal disease history and incident cancer in the women’s health initiative study of postmenopausal women. We found that women reporting periodontal disease history were at increased risk of developing cancer overall. In addition they were found to have significant increased risk of specific cancers including cancers of the lung, breast, esophagus, gallbladder and melanoma. The risk persisted after control for many other factors. In addition, the risk was seen in women regardless of their smoking history. Both ever smokers and never smokers were found to have increased risk of cancer associated with periodontal disease history.

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Diabetes Alters Oral Microbiome Leading to Periodontal Disease

MedicalResearch.com Interview with:

Dana T. Graves DDS Department of Periodontics School of Dental Medicine University of Pennsylvania Philadelphia, PA

Dr. Graves

Dana T. Graves DDS
Department of Periodontics
School of Dental Medicine
University of Pennsylvania
Philadelphia, PA

MedicalResearch.com: What is the background for this study? What are the main findings?

Response: It was previously thought that diabetes did not have a significant effect on oral bacteria. We found that diabetes caused a change in the composition of the oral bacteria. This change caused resulted in a bacterial composition that was more pathogenic and stimulated more inflammation in the gums and greater loss of bone around the teeth.

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Engineering New Vasculature Could Revolutionize Root Canal Surgery

MedicalResearch.com Interview with:
Avathamsa Athirasala, MSE and
Luiz E. Bertassoni, DDS PhD

Biomaterials and Biomechanics, School of Dentistry
Center for Regenerative Medicine, School of Medicine
Biomedical Engineering, School of Medicine
Portland OR 97201 USA

MedicalResearch.com: What is the background for this study? What are the main findings?

Response: Current clinical practices for root canal treatment involve replacing the damaged tissue with inert, synthetic materials. While these procedures are able to arrest infection and decay in the tooth, they do not restore its biological function causing it to become weaker and more prone to fractures.

We are focused on the regeneration of pulp tissue instead and in this study, we have developed a strategy to apply tissue-engineering concepts to engineer dental pulp-like tissue constructs, complete with blood vessels, which can, in principle, integrate with existing vasculature when introduced at the site of injury and form healthy pulp tissue. Continue reading

Frequent Marijuana Use Linked To Increased Risk of Severe Periodontal Disease

MedicalResearch.com Interview with:

Jaffer A Shariff DDS MPH cert.DPH Periodontal Resident | Research Scientist Division of Periodontics, Columbia University College of Dental Medicine New York

Dr. Shariff

Jaffer A Shariff DDS MPH cert.DPH
Periodontal Resident | Research Scientist
Division of Periodontics,
Columbia University College of Dental Medicine
New York

MedicalResearch.com: What is the background for this study? What are the main findings?

Response: Marijuana use for both medical and recreational purposes has become increasingly common in recent years; it is the most commonly used recreational drug in the United States. Subsequent increase in its legalization among countries including the United States for recreational purposes, poses an emergent oral and periodontal health concerns.

Our study revealed that frequent recreational marijuana users exhibited deeper periodontal probing depths, clinical attachment loss and higher odds of having severe periodontal disease than the non-frequent users, even after controlling for other risk factors linked to gum disease, such as cigarette smoking.

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In Accordance With Guidelines, Fewer Low Risk Patients Receiving Antibiotics Before Dental Procedures

MedicalResearch.com Interview with:

Daniel C. DeSimone, M.D.</strong> Infectious Diseases Fellowship, Year 2 Mayo Clinic

Dr. DeSimone

Daniel C. DeSimone, M.D.
Infectious Diseases Fellowship, Year 2
Mayo Clinic

MedicalResearch.com: What is the background for this study?

Response: For over 50 years, the American Heart Association (AHA) has recommended antibiotics to be given to patients with certain cardiac conditions prior to invasive dental procedures (dental cleanings, extractions, root canals) with the hope to prevent infective endocarditis–a potentially deadly infection of the heart valves. Prevention of this infection was preferred to treatment of an established infection due to its high morbidity and mortality rates. However, in 2007, experts found that there was very little, if any, evidence that showed antibiotics prophylaxis prevented infective endocarditis prior to invasive dental procedures. Given this, the AHA revised its guidelines, significant reducing the number of patients where antibiotic prophylaxis would be given–as routine daily activities such as chewing food, tooth brushing, and flossing were much more likely to cause infective endocarditis than a single dental procedure.

For over 50 years, patients with cardiac conditions that placed them at “moderate risk” and/or “high risk” were to receive antibiotics prior to dental procedures. In 2007, the “moderate risk” group were to no longer receive antibiotic prophylaxis. This is a significantly large proportion of patients–approximately 90% of all patients who would have received antibiotic prophylaxis. Given the drastic changes made in 2007, there was concern among the medical and dental communities about whether we were leaving patients “unprotected” and at risk for infective endocarditis. Thankfully, several population based studies from our group and others across the United States have not shown an increase in the rate of infective endocarditis. However, the question remained, “Are providers following the 2007 AHA guidelines?” and “Are patients still receiving antibiotics prior to dental procedures when its no longer indicated by the guidelines?”.

This was the main focus of our paper. We were able to go into the local dental offices and at the same time, have full access to their medical records. Every dental visit between 2005 and 2015 at their dental office was reviewed; the type of dental visit, whether they received antibiotic prophylaxis or not. In addition, we could confirm their cardiac conditions that would place them at “moderate risk” or “high risk” compared to the general population.

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Oral Bacteria Linked to Cardiovascular Disease

MedicalResearch.com Interview with:
Bradley F. Bale, M.D.

Texas Tech Health Science Center
School of Nursing, Lubbock, Texas
1002 Montrose Drive
Gallatin, TN 37066

MedicalResearch.com: What is the background for this study? What are the main findings?

Response: It has been known for some time that periodontal disease is associated with higher risk for arterial disease.  It was shown decades ago that the germs in the mouth frequently seed into our blood stream with simple activities such as chewing and brushing our teeth.  During the last decade, it was discovered certain high risk periodontal pathogens are associated with various cardiovascular (CV) risk factors such as blood pressure, lipid levels, insulin resistance and endothelial dysfunction.  These studies elucidated that the CV risk stems from the bacteria involved in the periodontal disease and not the clinical signs such as pocket depth, bleeding of gums and loose teeth.

The above knowledge demonstrated that high risk periodontal pathogens can adversely influence two of the three elements in the atherogenic triad.  Those factors are concentration of apoB and endothelial inflammation and dysfunction.  Then approximately two years ago it was published that the high risk pathogen Porphyromonas  gingivalis (P.g.) can enhance the third element.  This portion is the transformation of contractile smooth muscle cells (SMCs) in the medial layer of artery into migratory secretory SMCs.  These morphed cells enter the deep layer of the intima and enrich it with proteoglycans which are the ‘velcro’ that traps cholesterol particles in the arterial wall and initiates the formation of arterial disease.  At that point, there was solid evidence that the high risk pathogens boost every element in the triad to create atherosclerosis.  With that knowledge these pathogens must be considered a contributory cause of arterial disease.  When a condition is causal it demands diagnosis and management to reduce the disease risk.

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Gum Disease Linked to Autoimmunity in Rheumatoid Arthritis

MedicalResearch.com Interview with:

Maximilian F. Konig, MD Department of Medicine Massachusetts General Hospital Harvard Medical School

Dr. Maximilian F. Konig

Maximilian F. Konig, MD
Division of Rheumatology,
Johns Hopkins University School of Medicine
Current affiliation:
Department of Medicine
Massachusetts General Hospital
Harvard Medical School

MedicalResearch.com: What is the background for this study?

Response:The idea that rheumatoid arthritis (RA), an autoimmune disease that leads to chronic joint inflammation and destruction, may be initiated by a bacterial infection is not novel, but has been posited for more than a century. Based on the clinical observation that patients with RA frequently have severe periodontal disease (gum disease), gum inflammation has long been thought to contribute to disease development in RA. However, limited understanding of the mechanisms that fuel and sustain the autoimmune attack in RA made it difficult to pinpoint a specific bacterial trigger.

In recent years, our understanding of the abnormal immune response that attacks the joints in patients with RA has grown exponentially, and we now know that disease-specific autoantibodies (ACPAs) target modified self-proteins (this modification is known as citrullination). It is this abnormal immune response against citrullinated proteins that appears to drive the joint (and sometimes lung) inflammation seen in rheumatoid arthritis. Recent studies from our laboratory at The Johns Hopkins University (led by principle investigator Felipe Andrade, MD, PhD) suggested that an immune cell called the neutrophil, which normally protects us from infection at sites like the oral cavity or anywhere else in the body, also appears to be the source of the proteins attacked in RA. We were therefore interested to understand what drives the association of gum disease, an inflammation commonly triggered by bacteria, with RA.

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