Dental implants frequently lead to complications

Almost 8 percent of patients experience loss of at least one implant within ten years. Even more develop peri-implantitis. Patients with periodontitis run a greater risk of both implant loss and peri-implantitis. A doctoral thesis at Sahlgrenska Academy has explored the various issues.

Approximately 30,000 Swedes receive dental implant therapy every year. The method is common in connection with partial or full edentulism (toothlessness), and Sweden is among the countries with the most dental implants per capita.

Biological complications

Previous evaluations have frequently been limited to observational studies of patient populations in specialist dental care. Few attempts have been made to analyze biological complications such as peri-implantitis, which is characterized by inflammation in adjacent tissues and loss of supporting jawbone.

A national project evaluated the therapy in terms of patient-reported outcomes, implant loss and prevalence of peri-implantitis.

High degree of satisfaction

"The results of the initial questionnaire survey, which included 4,716 randomly selected patients, indicated a high degree of satisfaction, particularly among men and older respondents," says Jan Derks, researcher at Sahlgrenska Academy.

Developed peri-implantitis

A total of 596 patients at 37 Swedish clinics were examined at a 9-year follow-up.

"Altogether, 7.6 % of patients had lost at least one implant and 14.5 % had developed peri-implantitis with pronounced bone loss," Dr. Derks says.

Patients suffering from periodontitis exhibited an increased risk of severe peri-implantitis, while both periodontitis and smoking were associated with early implant loss.

Progresses quickly

"Peri-implantitis appears to develop within a few years and then progresses quickly and at an accelerating pace," Dr. Derks says.

The results of the study provide crucial input to both patients and dental practitioners in the effort to minimize the risk of implant loss and peri-implantitis.

Preventing dental implant infections

One million dental implants are inserted every year in Germany, and often they need to be replaced due to issues such as tissue infections caused by bacteria. In the future, these infections will be prevented thanks to a new plasma implant coating that kills pathogens using silver ions.

Bacterial infection of a dental implant is a dreaded complication, as it carries with it a high risk of jawbone degeneration. Implanting an artificial dental root sets off a race between infectious pathogens and the body's own cellular defenses. If the bacteria win, they form a biological film over the titanium to protect themselves from anti-biotics. Once the implant is colonized by germs, the result is an inflammatory reaction, which can result in bone atrophy.

To lower the risk of infection and improve the long-term effectiveness of the implant, researchers at the Fraunhofer Institute for Manufacturing Technology and Advanced Materials IFAM in Bremen have developed a new type of implant coating in cooperation with industry partners. The DentaPlas coating helps prevent the growth of bacteria, thus allowing the implant to properly take hold and thereby form a faster and more permanent bond with the jawbone. The trick to this lies in combining surface materials that feature physical as well as chemical properties. "We have given the DentaPlas coating a rough texture, which promotes cellular growth, in addition to combining it with a hydrophilic plasma polymer coating, which attracts moisture," says Dr. Ingo Grunwald, project manager at the IFAM. Researchers have integrated silver nanoparticles into the thin plasma polymer coating, which is up to just 100 nanometers thick. The silver nanoparticles dissolve over a period of several weeks, and during that time they continuously release small quantities of anti-microbial silver ions, which kill bacteria.

Three layers of protection

"The DentaPlas system consists of three layers, with two plasma polymer layers surrounding a center layer of silver. Within this structure a biocide reservoir is formed, and the outermost layer releases the ions. This is beneficial because it prevents direct contact between the tissue and the silver particles, which can be toxic when exposed," says developer Dr. Dirk Salz. Researchers can tailor the silver concentration as well as the thickness of the layers and their porosity. This allows the silver ions to penetrate the outermost plasma polymer layer over a set period of time deemed necessary to properly integrate the implant. When the silver reservoir is exhausted, no more silver ions are released, thus avoiding any long-term toxic effects.

In trials using finished implants and titanium test samples, the IFAM researchers demonstrated that the DentaPlas coating is not only anti-microbial but also fully biocompatible and sterilizable. The test samples were coated using a plasma polymerization facility at the IFAM in Bremen. Researchers confirmed the mechanical stability and robustness of the DentaPlas coating in trials using the lower jawbones of pigs taken from butcher shops. Here, they subjected the DentaPlas coated implants to the rigors of being screwed into place using the instruments found in modern dental practices. The DentaPlas coating passed this stress test with flying colors. Project partner and Fraunhofer spinoff Bio Gate AG successfully transferred the processes of coating the test samples and titanium screws to its own production facilities. The medical tech-nology company is also the manufacturer of the DentaPlas three-layer coating system.

Diamonds -- a tooth's best friend?

Gold, silver and porcelain are among the many materials dentists can use to fix damaged teeth. Soon diamonds -- at least tiny, microscopic ones -- could be added to that list. Scientists have developed a new material with nanodiamonds that has the potential to improve current root canal therapies and help prevent future infection. Their report appears in the journal ACS Nano.

Millions of Americans undergo root canals every year to clear out damaged or infected pulp, the soft part in the middle of a tooth. Dentists' current go-to material to fill the space left behind is a rubber compound called gutta-percha. In some cases, however, a patient's tooth can get re-infected, which calls for another treatment. To prevent this from happening, researchers have been exploring other fillers, including nanodiamonds, which are robust and can be modified with antimicrobial drug compounds. So Dean Ho and colleagues decided to develop a potential root canal therapy based on them.

The team combined nanodiamonds, gutta-percha and amoxicillin, a broad-spectrum antibiotic, into a new material. Lab testing showed it was stronger than gutta-percha by itself and was effective at killing Staphylococcus aureus, which is one of the bacteria responsible for root canal re-infections. The scientists say future studies will check whether the composite works in clinical practice.

Smokers at higher risk of losing their teeth, research shows

A new study has confirmed that regular smokers have a significantly increased risk of tooth loss.

Male smokers are up to 3.6 times more likely to lose their teeth than non-smokers, whereas female smokers were found to be 2.5 times more likely.

The research, published in the Journal of Dental Research, is the output of a long-term longitudinal study of the EPIC Potsdam cohort in Germany carried out by researchers at the University of Birmingham and the German Institute of Human Nutrition.

Tooth loss remains a major public health problem worldwide. In the UK, 15% of 65-74 year olds and over 30% of 75+ year olds are edentate (have lost all of their natural teeth). Globally, the figure is closer to 30% for 65-74 year olds.

Lead author Professor Thomas Dietrich, from the University of Birmingham, explained, "Most teeth are lost as a result of either caries (tooth decay) or chronic periodontitis (gum disease). We know that smoking is a strong risk factor for periodontitis, so that may go a long way towards explaining the higher rate of tooth loss in smokers."

Smoking can mask gum bleeding, a key symptom of periodontitis. As a result, the gums of a smoker can appear to be healthier than they actually are.

Professor Dietrich added, "It's really unfortunate that smoking can hide the effects of gum disease as people often don't see the problem until it is quite far down the line. The good news is that quitting smoking can reduce the risk fairly quickly. Eventually, an ex-smoker would have the same risk for tooth loss as someone who had never smoked, although this can take more than ten years."

Kolade Oluwagbemigun, from the German Institute of Human Nutrition, said, "Gum disease and consequential tooth loss may be the first noticeable effect on a smoker's health. Therefore, it might give people the motivation to quit before the potential onset of a life-threatening condition such as lung disease or lung cancer."

The findings were independent of other risk factors such as diabetes, and are based on data from 23,376 participants which aimed to evaluate the associations between smoking, smoking cessation and tooth loss in three different age groups.

The association between smoking and tooth loss was stronger among younger people than in the older groups. In addition, the results clearly demonstrated that the association was dose-dependent; heavy smokers had higher risk of losing their teeth than smokers who smoked fewer cigarettes.

Professor Heiner Boeing, also from the German Institute of Human Nutrition, added, "In addition to the many noted benefits for cardiovascular health, and risk of lung disease and cancer, it is clear that dental health is yet another reason not to take up smoking, or to quit smoking now."

Supervised tooth brushing and floride varnish schemes benefit kids and the health economy

Action to prevent tooth decay in children, such as supervised tooth brushing and fluoride varnish schemes, are not just beneficial to children's oral health but could also result in cost savings to the NHS of hundreds of pounds per child, so says a leading dental health researcher.

Professor Elizabeth Kay, Foundation Dean of the Peninsula Dental School from Plymouth University Peninsula Schools of Medicine and Dentistry, has carried out the first economic evaluation of public health measures to reduce tooth decay in children at high risk, in association with the National Institute for Health and Care Excellence (NICE) and the York Health Economic Consortium. She will present her findings at this year's British Society for Oral and Dental Research Annual Meeting in Cardiff, 14th to 16th September.

Almost 26,000 children a year aged between five and nine are admitted to hospital for dental treatment under general and local anaesthetic in the UK, for conditions which are on the whole preventable through better understanding and adoption of good oral health routines.

In her study Professor Kay found that, taking the threshold value used by NICE of £20,000 per Quality Adjusted Life Year (QALY), preventive schemes targeted at high risk children would be considered to be cost-effective even if they cost £46 per year per child for tooth brushing or £62 per child per year for fluoride varnish schemes. This would represent a saving of hundreds of pounds per child when compared with the cost of surgical treatments in hospital.

QALY is used in assessing the value for money of a medical intervention.

The model showed that for children at high risk of oral disease, supervised brushing and fluoride varnish schemes are cost-effective options.

Said Professor Kay: "We have more work to do here to translate the results of our study into policy, but I must stress that this is about more than making better use of NHS funds, and demonstrating that oral health promotion programmes offer extremely good value for money. I think it is a national outrage that so many children in the UK are admitted to hospital for surgical procedures for conditions which are by and large preventable. If there was a health issue that resulted in this number of children having another body part removed under general or local anaesthetic there would be a justifiable national outcry, yet for many reasons tooth extraction appears to have become accepted in some circles. This study demonstrates that it is also economically viable and sensible to prevent tooth decay"

She added: "By showing sound economic reasons for increasing the use of preventative measures, such as tooth brushing and fluoride varnishing, I hope that they can now compete for resource against other less cost-effective interventions."

Dentists tapped for new role: Drug screenings

 

A visit to the dentist has the potential to be more than a checkup of our teeth as patients are increasingly screened for medical conditions like heart disease and diabetes. A new study by researchers at Columbia University's Mailman School of Public Health focuses on dental screenings for drug misuse, finding 77 percent of dentists ask patients about illicit drug use, and 54 percent of dentists believe that such screenings should be their responsibility. Results of the study are online in the journal Addiction.

"There are a sizeable number of people whose visit to a dentist represents their sole interaction with the healthcare system, highlighting the significance of the dental visit as a key opportunity to identify substance use disorders," said Carrigan Parish, DMD, associate research scientist in the Department of Sociomedical Sciences. "However, our findings underscore a significant barrier in dentists' attitudes that may limit the potential of the dental venue to play a role in screening for substance misuse."

The researchers, led by Lisa Metsch, PhD, principal investigator and Stephen Smith Professor and chair of the Department of Sociomedical Sciences, sampled 1,802 U.S. dentists in general practice from a nationally representative survey by the American Dental Association Survey Center conducted from 2010 to 2011. The survey achieved a very high response rate of 71 percent, increasing the ability of the survey results to capture a complete picture of the U.S. dental workforce. According to Metsch, "there is an increasing recognition about the need to better integrate oral and systemic health," and "questions remain about the feasibility of offering preventive screening and testing alongside dental care--many of which are being answered in this study."

Those dentists who embraced substance misuse screening as part of their professional role were more likely to query about misuse with their patients (86 percent) compared with those who did not accept such screenings as their responsibility (68 percent). In general, both agreement with the purpose of and use of health history forms with substance misuse questions increased with the amount of prior training and knowledge regarding substance use. 

Older dentists were less likely to report that their health history form included questions about substance misuse than those who were younger. Dentists under the median age of 53 were also more apt to say that illicit drug use screening should be part of the dentist's role than their more senior counterparts (62 percent versus 47 percent). As with age, agreement with screening as part of dentists' role and health history form screening increases markedly with how recently the dentist graduated.

Gender was also associated with dentists' attitudes toward screenings. More female dentists (61 percent) than their male counterparts (52 percent) agreed that illicit drug use screening should be the role of the dentist. 

Drug use can have a negative impact on dental health as well as overall health. Patterns of oral health pathology attributed to methamphetamine users, for example, include rampant tooth decay, accelerated tooth wear, unexplained advanced gum disease, missing multiple teeth, and overall detrimental dental effects that are rapid and severe. These patients also often seek cosmetic dental treatment, such as veneers and whitening, which give dentists another opportunity to discuss suspected substance misuse, provide referrals for treatment, and encourage cessation of drug misuse. 

Furthermore, dentists are the second-largest group of prescribers of opioid pain medication. "Because dental care routinely involves treating pain and emergencies, dentists may encounter substance-seeking patients who complain of pain more severe than anticipated based on the nature of their dental condition, who report lost prescriptions for opioid pain medications, or who only seek dental treatment sporadically," noted Parish. 

"In order for substance misuse screening to be compatible with the dental setting, two-way communication between patient and dentist needs to occur more openly," observed Parish. "While surveys have shown that patients are amenable to receiving medical screenings by dentists 'chair-side' for such conditions as HIV, heart disease, and diabetes, further studies directly addressing patient attitudes on substance misuse screening are key in determining patients' acceptance of such services." Dentists may also need additional education to increase their awareness, comfort, and knowledge of substance misuse, given that "dentists are well situated to make appropriate referrals to treatment centers if instilled with the proper training and supports."

JDR articles discuss diet, dental caries and health policy

Today, the International and American Associations for Dental Research (IADR/AADR) published two reports including a critical review titled "Diet and Dental Caries - the Pivotal Role of Free Sugars Reemphasized." In this study, authors Aubrey Sheiham, University College London, England; and W. Philip James, London School of Hygiene and Tropical Medicine, England, demonstrate the sensitivity of cariogenesis (the development of caries) to even very low sugars intakes. In this critical review, the authors reviewed the literature on the role of sucrose in the cariogenic process and conclude there is extensive scientific evidence that free sugars are the primary necessary factor in the development of dental caries.

This year, the World Health Organization (WHO) published a guideline on sugars intake for adults and children. The objective of the WHO guideline is to provide recommendations on intakes of free sugars to reduce risks of NCDs in adults and children, with a particular focus on the prevention and control of unhealthy weight gain and dental caries. WHO recognized that dental diseases are the most prevalent noncommunicable diseases globally and the treatment of dental diseases is expensive, and would exceed the entire financial resources available for the health care of children in most lower income countries. In this guideline, WHO recommends reducing the intake of free sugars to less than 10% of total energy intake.

A dose-response relationship between the sucrose or its monosaccharide intakes and the progressive life-long development of caries was demonstrated. This situation results in a substantial dental health burden throughout life.

Beau Meyer and Jessica Lee, The University of North Carolina at Chapel Hill, USA, commented on these findings in a perspective article titled "The Confluence of Sugar, Dental Caries and Health Policy". In this paper Meyer and Lee underscore the relationship between sugars intake and dental caries, and implications for health policy interventions. They emphasize that as policies surrounding limiting sugar intake continue to evolve, attention must be given to how best to put these policies into practice to produce positive behavior change that ultimately should lead to improved oral health outcomes.