Friday, March 24, 2017

New study identifies successful method to reduce dental implant failure


UNIVERSITY OF PLYMOUTH
IMAGE
IMAGE: NEW NANOCOATING SHOWS PROMISE IN DENTAL IMPLANT PROTECTION. view more 
CREDIT: UNIVERSITY OF PLYMOUTH
According to the American Academy of Implant Dentistry (AAID), 15 million Americans have crown or bridge replacements and three million have dental implants -- with this latter number rising by 500,000 a year. The AAID estimates that the value of the American and European market for dental implants will rise to $4.2 billion by 2022.
Dental implants are a successful form of treatment for patients, yet according to a study published in 2005, five to 10 per cent of all dental implants fail.
The reasons for this failure are several-fold - mechanical problems, poor connection to the bones in which they are implanted, infection or rejection. When failure occurs the dental implant must be removed.
The main reason for dental implant failure is peri-implantitis. This is the destructive inflammatory process affecting the soft and hard tissues surrounding dental implants. This occurs when pathogenic microbes in the mouth and oral cavity develop into biofilms, which protects them and encourages growth. Peri-implantitis is caused when the biofilms develop on dental implants.
A research team comprising scientists from the School of Biological Sciences, Peninsula Schools of Medicine and Dentistry and the School of Engineering at the University of Plymouth, have joined forces to develop and evaluate the effectiveness of a new nanocoating for dental implants to reduce the risk of peri-implantitis.
The results of their work are published in the journal Nanotoxicology.
In the study, the research team created a new approach using a combination of silver, titanium oxide and hydroxyapatite nanocoatings.
The application of the combination to the surface of titanium alloy implants successfully inhibited bacterial growth and reduced the formation of bacterial biofilm on the surface of the implants by 97.5 per cent.
Not only did the combination result in the effective eradication of infection, it created a surface with anti-biofilm properties which supported successful integration into surrounding bone and accelerated bone healing.
Professor Christopher Tredwin, Head of Plymouth University Peninsula School of Dentistry, commented: "In this cross-Faculty study we have identified the means to protect dental implants against the most common cause of their failure. The potential of our work for increased patient comfort and satisfaction, and reduced costs, is great and we look forward to translating our findings into clinical practice."
The University of Plymouth was the first university in the UK to secure Research Council Funding in Nanoscience and this project is the latest in a long line of projects investigating nanotechnology and human health.
Nanoscience activity at the University of Plymouth is led by Professor Richard Handy, who has represented the UK on matters relating to the Environmental Safety and Human Health of Nanomaterials at the Organisation for Economic Cooperation and Development (OECD). He commented: "As yet there are no nano-specific guidelines in dental or medical implant legislation and we are, with colleagues elsewhere, guiding the way in this area. The EU recognises that medical devices and implants must: perform as expected for its intended use, and be better than similar items in the market; be safe for the intended use or safer than an existing item, and; be biocompatible or have negligible toxicity."
He added: "Our work has been about proving these criteria which we have done in vitro. The next step would be to demonstrate the effectiveness of our discovery, perhaps with animal models and then human volunteers."
Dr Alexandros Besinis Lecturer in Mechanical Engineering at the School of Engineering, University of Plymouth, led the research team. He commented: "Current strategies to render the surface of dental implants antibacterial with the aim to prevent infection and peri-implantitis development, include application of antimicrobial coatings loaded with antibiotics or chlorhexidine. However, such approaches are usually effective only in the short-term, and the use of chlorhexidine has also been reported to be toxic to human cells. The significance of our new study is that we have successfully applied a dual-layered silver-hydroxyapatite nanocoating to titanium alloy medical implants which helps to overcome these risks."

Wednesday, March 8, 2017

Study links changes in oral microbiome with metabolic disease/risk for dental disease


A team of scientists from The Forsyth Institute and the Dasman Diabetes Institute in Kuwait have found that metabolic diseases, which are characterized by high blood pressure, high blood sugar, and obesity -- leads to changes in oral bacteria and puts people with the disease at a greater risk for poor oral health. This study of more than 8,000 ten year olds in Kuwait showed that metabolic diseases lead to increases in salivary glucose; alterations of the bacteria found in the mouth; and increased risk of cavities and gum disease. This work reinforces the need for preventive dental care and greater integration between medical and dental care. 



The study, titled, "The Salivary Microbiome is altered in the Presence of High Salivary Glucose," can be found on PLOS ONE. Over the past ten years, it has become clear that defining a "healthy" microbiome is a critical step for discovering how variations in the bacteria found in and on our body contribute to both disease and wellbeing. While scientists now know a great deal about what bacteria live in our mouth and throughout the body, it is still unclear whether differences in the human microbiome that are seen in many disease states are a symptom of the disease or part of the underlying cause. 
"The mouth represents a rich microbiome that is easily accessible," said Dr. Max Goodson, the study's lead author. "Our research is providing further evidence of the connections between the mouth and some of society's most costly and deadly systemic diseases--and of the importance of using the mouth as a tool for preventive health." 

Summary of Study
We measured the glucose concentration, bacterial counts, and relative frequencies of 42 bacterial species in whole saliva samples from 8,173 Kuwaiti adolescents (mean age 10.00 ± 0.67 years) using DNA probe analysis. In addition, clinical data related to obesity, dental caries, and gingivitis were collected. Data were compared between adolescents with high salivary glucose (HSG); glucose concentration and those with low salivary glucose. Investigators found that HSG was associated with dental caries and gingivitis in the study population. The overall salivary bacterial load in saliva decreased with increasing salivary glucose concentration. Under HSG conditions, the bacterial count for 35 (83%) of 42 species was significantly reduced, and relative bacterial frequencies in 27 species (64%) were altered, as compared with LSG conditions. These alterations were stronger predictors of high salivary glucose than measures of oral disease, obesity, sleep or fitness. These observations clearly indicate that metabolic diseases, such as diabetes, that produce elevated glucose in blood and saliva can significantly alter the oral microflora. 
Samples were obtain through the Forsyth Kuwait Healthy Life Study, is a longitudinal cohort investigation of more than 8,000 children. Forsyth has worked with The Dasman Diabetes Institute and the Kuwait/Forsyth School program to conduct a clinical investigation of the development of obesity, metabolic syndrome and type 2 diabetes in Kuwaiti children. During the five-year study, the body weight, height, blood pressure and fitness were measured, oral disease was evaluated, nutritional information was collected, questionnaires on sleep and medical history were answered and saliva was collected for analysis.


Tooth loss linked to an increased risk of dementia


In a study of 1566 community-dwelling Japanese elderly who were followed for 5 years, the risk of developing dementia was elevated in individuals with fewer remaining teeth. 
Individuals with 10-19, 1-9, and no teeth had 62%, 81%, and 63% higher risks of dementia, respectively, than individuals with >20 teeth. Likewise, an inverse association was observed between the number of remaining teeth and the risk of developing Alzheimer's disease. 
"Our findings emphasize the clinical importance of dental care and treatment, especially in terms of maintenance of teeth from an early age for reducing the future risk of dementia," said Dr. Tomoyuki Ohara, co-author of the Journal of the American Geriatrics Society study.