Instant insight: Smart dental implants

Instant insight: Smart dental implants

Henning Schliephake from the George-Augusta University, Göttingen, Germany, discusses the state-of-the-art dental implants making their way to a dentist's surgery near you

Dental implants are screws or cylinders, commonly made of titanium, which are inserted into the jaw bone in a surgical procedure. They act as artificial roots and can provide anchorage to crowns and bridges after the original root has been lost. Close contact between the adjacent bone and the implant surface is important for the artificial roots to remain fixed for the long-term. This bone-to-implant contact is accomplished by the growth of new bone on the titanium surface. The adsorption of biomolecules and blood components onto the titanium from the body fluids surrounding the implant is a crucial step in this process. This allows bone cells and their precursors to approach the surface and start growing bone tissue. Bone healing may be compromised by previous infection, radiotherapy or osteoporosis, and this can jeopardise the process and lead to implant failure.

In recent years, material scientists and clinicians have developed a number of approaches to improving the regenerative capacity of adjacent bone. One strategy is to create surface conditions that encourage quicker and more intense adsorption of biomolecules onto the implant surface, by altering the implants surface morphology and surface chemistry. Increasing the surface roughness using acid etching and sandblasting combined with integration of fluoride ions or calcium phosphate nanocrystals considerably increases the speed and strength of the bone-implant contact.

An alternative way of enhancing bone formation on the implant surface is using biological signals to attract bone cells to the surface and increase the speed they grow. Some of these signals are based on a short sequence of amino acids - the so called RGD motifs - that bind to specific receptors on the cell surface initiating cell migration and/or increasing cellular activity. The signals are held in place by various types of linker molecules that are anchored to the titanium surface.

Another way to accelerate bone growth is using signalling molecules or growth factors to accelerate cellular specialisation. As bone forming cells originate from so called precursor cells, using osteogenic signalling molecules such as bone morphogenic proteins on the implant surface could considerably increase the number of bone forming cells and therefore the amount and strength of the bone grown.

In native bone, many of these osteogenic signalling molecules are encased in the bone matrix, a highly structured assembly of minerals and proteins, which provides three-dimensional stability to the bone tissue. This reservoir of growth factors aids the healing process of bone, for example after a fracture. The most complex approaches among recent surface modifications of titanium implants have tapped into this source to produce matrix-engineered surfaces. Here bone matrix proteins such as collagen are arranged on the implant surface, together with molecules that bind growth factors in native bone, to provide a reservoir for osteogenic signals that are slowly released from the surface in a nature-like fashion after implant placement.

Many of these biological approaches have yet to work their way from the bench to the bedside. However, the huge potential of this research and improved biotechnological capabilities will eventually prove useful for the incorporation of many types of artificial materials into the human body - extending far beyond the integration of dental implants.

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Turning the light off on tooth bleaching

Turning the light off on tooth bleaching

Norwegian scientists have demonstrated that light sources often used as part of the tooth bleaching process do not contribute to the effectiveness of the process and may pose possible health risks.

Tooth bleaching is becoming a popular way to remove stains on the teeth caused by smoking, red wine, tea and coffee, in an attempt to achieve a Hollywood smile. The process used by dentists to bleach teeth involves applying an oxidising agent to the teeth and in some cases a light source is then shone onto the teeth.

Ellen Bruzell from the Nordic Institute of Dental Materials, Haslum, and colleagues, measured the effectiveness of teeth bleaching using seven different commercially available products, with and without using light sources. The claim that light-assisted tooth bleaching is more efficient than ordinary bleaching has not been substantiated in the literature, explains Bruzell. She says that they found a 'lack of additional whitening effect when light is used compared to bleaching without light'.

The team also demonstrated that for the majority of the light sources tested, the amount of radiation a person is exposed to during the bleaching process poses a risk of damage to the skin and eyes if proper protection is not used. Thomas Attin, an expert in preventative and restorative dentistry from the University of Zurich, Switzerland, comments that this study is very interesting and says that 'the aspect that the light sources used for bleaching may cause some risks (not only to the teeth) is new.'

Bruzell also found an increase in exposed perichymata (grooves on the surface of the tooth enamel) on the bleached teeth compared to unbleached control teeth, showing that the tooth bleaching process removes part of the pellicle that covers the enamel's surface, making the teeth more vulnerable to mechanical stress.

Bruzell says she is now carrying out a study on the effectiveness of first time tooth bleaching. Future work may also include investigating the effects of optical radiation on oral tissue and looking into the adverse effects of repetitive tooth bleaching, she adds.

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Cancer-causing gene discovery suggests new therapies

Scientists have discovered a novel way by which a much-studied cancer-promoting gene accelerates the disease. The finding suggests a new strategy to halt cancer's progress.

Up to now, research has largely focused on how the mutated gene, Myc, disrupts the ability of DNA to be "transcribed" into RNA – the first step in making proteins that are essential for cell growth and function. But the new research shows that this altered Myc gene, called an oncogene, can also act directly on the final stage of protein production.

The finding in mice suggests that drugs already available to counter this increased protein production could slow or stop cancer's runaway growth induced by Myc. Rapamycin, for example, an immunosuppressant drug already in clinical trials for cancer, might help treat cancers where Myc is over active, the scientists suggest.

According to a press release by EurekAlert, the discovery was led by Davide Ruggero, PhD, and Maria Barna, PhD, faculty scientists at the University of California San Francisco (UCSF).

Study findings were published in the journal "Nature" (December 18, 2008).

"Control of protein production rapidly affects cell behavior, and in a robust manner," explains Ruggero, assistant professor of urology at the UCSF Helen Diller Family Comprehensive Cancer Center and co-senior author on the paper with Barna. "The ability of the Myc oncogene to directly alter this process may well explain the rapid progression of cancer formation."

Scientists have known for some time that when the Myc gene is mutated and becomes an oncogene, it interferes with the early steps in DNA activity in the cell nucleus. But how the oncogene affected the subsequent production of proteins, a step known as translation, was unknown.

"A cancer causing gene, such as Myc, regulates many distinct cellular processes, and that can make it very difficult to tease apart which ones are the most important for the cancer to progress," says Barna, a faculty fellow in the UCSF biochemistry and biophysics department. "The key to our studies was the ability to generate novel genetic tools to halt Myc's action on protein production. This demonstrates how essential this process is for cancer formation."

To test whether protein production induced by Myc played a role in cancer, the UCSF- led team genetically crossed two types of mice: one that was cancer-prone and overexpressed the Myc oncogene and one that was newly engineered to lower protein production. The new cross of mice possessed not only the well-known destructive Myc traits, but also an enhanced ability to damp down protein production.

In these mice, the restrained protein production restored to near-normal the cell growth, division and protective cell-sacrifice needed to counter cancer.

The scientists also found that this increased control over the so-called "translation" of RNA into proteins countered damage to chromosome function otherwise caused by Myc, and preserved functions vital to faithful cell division. Changes in the genetic integrity of cells are recognized as hallmarks of cancer, and the new findings show that Myc can cause these abnormalities through control of protein production.

The research suggests that Myc may disrupt a number of genes "downstream" of its damage to DNA, the scientists say.

"We discovered a previously unrecognized link between alterations in protein synthesis and the mechanism by which cells maintain the integrity of the genome," Ruggero stresses. "We found that when Myc is overexpressed, this leads to changes in protein levels of a key gene that is essential for normal distribution of genetic material between daughter cells during cell division."

The findings are a positive step, he emphasizes, because they suggest that halting Myc's action on protein production with targeted therapies could prevent harmful genetic changes in cells that lead to cancer progression.

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Measles virus derivatives boon for prostate cancer

Washington (IANS): Certain measles virus vaccine strain derivatives can effectively infect and kill prostate cancer cells.

Prostate cancer is the second most common cause of cancer-related deaths among American men with an estimated 186,320 new cases and 28,660 deaths in 2008.

A sizeable proportion of these patients ultimately relapse, with a five-year failure rate for treatment ranging from 14 to 34 percent. No curative therapy is currently available for locally advanced or metastatic prostate cancer.

The median survival time of mice treated with a virus derivative MV-CEA in the study almost doubled compared to the controls, and complete tumour regression was observed in a fifth of the treated animals.

"Based on our preclinical results as well as the safety of measles derivatives in clinical trials against other tumour types, these viral strains could represent excellent candidates for clinical testing against advanced prostate cancer, including androgen resistant tumours," said Evanthia Galanis, Mayo Clinic, senior author of the study.

The measles vaccine strains also have an excellent safety record with millions of vaccine doses having been safely administered in over 40 years of use, said a Mayo clinic release.

The new study appeared in The Prostate.

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“Invisalign” Straighten your teeth without braces

“Invisalign” Straighten your teeth without braces

For complete online solutions to all your dental problems do come to www.invisaligntopdentist.com. Here every patient is treated with complete care and giving personal attention to each patient. At Dr. Pannus Institute you are provided with many dental solutions, one of the most famous of them being Invisalign, for which Dr. Pannu has also received the Invisalign Innovator Award and is considered among the top 1% Invisalign practitioners in North America, having achieved an extra ordinary level of Invisalign experience.

Invisalign is the invisible way to straighten your teeth without braces, using a series of clear removable aligners to straighten your teeth without metal wires or brackets. You wear each set of clear invisible aligners for about 2 weeks, removing them only to eat, drink, brush, and floss. As you replace each aligner with the next in the series, your teeth will move - little by little, week by week - until they have straightened to the final position your orthodontist or dentist has prescribed.

Other than Invisalign they also provide their patients with many other solutions like 'Veneers' which is the attachment of a slender ammo porcelain to the exterior of the patients teeth o get better the glance of a extensive assortment of dental defect 'Root Canal' which is the procedure of treating the internal structure damages of your teeth and other major dental solutions being Lumineer, dental filling, infant dental care and dental implantation.

They also have the facility of cosmetic dentistry which actually helps his patients to have the best smile. It is the field of dentistry that focuses on improving the appearance of the mouth (teeth and gums) unlike traditional dentistry that focuses on the prevention, diagnosis, and treatment of oral diseases .Cosmetic dentistry uses tooth whitening, bonding and porcelain veneers to create a more youthful smile. So now all your dental solutions are just a click away.

Source :- “Invisalign” Straighten your teeth without braces

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Take care of oral health

As we enter 2009, many of us have already adopted a resolution for the New Year. While beginning a diet, committing to an exercise routine or spending more time with family are great choices, placing a priority on your oral health should be near the top of anyone's list.

Medical research has found that infections or bacteria in the mouth are linked to overall health. Periodontal (gum) disease, an infection of the tissues that support the teeth, is closely associated with the development of strokes, heart disease, pre-term births and pneumonia.

Additionally, people with diabetes are more likely to have gum disease, which can make it more difficult for diabetics to control their blood sugar. Gum disease may also be a risk factor for diabetes, even in people who are otherwise healthy.

You can help minimize your risk by following good oral-hygiene steps and visiting your dentist twice a year for exams and cleanings. Oral cancer screens are part of routine dental exams, and new advanced technology can help detect oral cancer at its earliest stages.

There are several things we can do on a daily basis to get on the right road to excellent oral health. Brush your teeth at least twice a day and floss at least once daily. Limit your intake of sweets, especially sugared, carbonated beverages. Eat more fruits and vegetables. Drink more water. Individuals with dentures should brush and rinse their dentures daily and clean with denture cleanser.

Remember, it is important to visit your dental team for regular exams, screenings and cleanings. Denture wearers are checked to ensure dentures fit properly.

Taking care of your oral health will help your overall health throughout the New Year and beyond.

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Town braced for new NHS dentist surgery

DENTISTS are expecting to be inundated with patients after a new NHS surgery was announced for a Suffolk town.

The new Bury St Edmunds practice is expected to open on Woolhall Street in April and is the first sign in the town of a package of investment tackling the county's NHS dentist shortage.

The announcement has been welcomed by patients and community leaders in an area where only 22% of practices are accepting new patients. And according to NHS Suffolk one-in-four 5-year-olds have decaying, missing or filled teeth.

The move comes after Suffolk health bosses conceded there was “significant unmet need” and “although there is a statutory duty to ensure that there is reasonable access to dentistry, it is not clear that this requirement is being met everywhere”.

The Bury practice set to be run as the White Cross practice and is part of a £1.8million overhaul to increase access for patients in response to the problem.

David Lockwood, chairman of Suffolk County Council's health scrutiny committee and St Edmundsbury Borough Council member, said: “This is great news for the west of the county. A new practice has already opened in Brandon and it has already begun making a difference.

“And the addition of investment orthodontic services is also going to be fantastic.”

The money, first announced last September, has also been earmarked for new practices in Sudbury, Hadleigh, Eye and Stowmarket, with further investment in Saxmundham, Woodbridge and Newmarket.

Among the recommendations to be implemented by the funding - of which £500,000 will be spent on orthodontics - people living in urban areas should be within five miles of a dentist and people living in rural areas should be no more than 12 miles away from a surgery.

A spokesman for NHS Suffolk said: “NHS Suffolk is spending £1.3million this year to improve access to dental services across the county, with a further £500,000 for orthodontic services.

“As part of this, we are now working closely with the owners to establish the new practice in Bury St Edmunds, and further details will be announced over the coming weeks.”

Source :- Town braced for new NHS dentist surgery

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Effective new malaria drug to be approved by FDA

Washington (IANS): The US Food and Drug Administration (FDA) is likely to approve a new malaria drug with artemisinin, a wormwood derivative from China that has proven effective for the infection in Africa and Asia.

Although only about 1,500 reported cases of malaria are treated in US annually, the drug would also be made available to the military and to Americans planning to go abroad.

However, worldwide malaria is still one of the most serious infectious diseases, claiming two million lives and affecting two to three billion people every year.

Named Coartem, the drug is made by Swiss company Novartis. It combines artemether, an artemesinin derivative, with lumefantrine, a drug developed by Chinese scientists, which does not kill parasites as quickly but lingers in the blood a while longer.

By mopping up parasites that artemisinin misses, lumefantrine helps prevent resistance that would defeat the drug, as has occurred with other therapies like chloroquine.

University of Pennsylvania pharmacologist Doron Greenbaum, said although the exact mechanism by which artemisinin kills parasites is still open to considerable debate, the drug likely acts against one or more protein targets that may make it susceptible to resistance that has developed to most other drugs.

Drug resistance to artemisinin has already been shown to occur in the lab, and reports have already surfaced about potential resistance in malaria endemic regions like southeast Asia.

Thus the potential success of Coartem treatment for malaria should be greeted with cautious optimism knowing that resistance is likely to arise and that other new drugs will need to be developed quickly.

Greenbaum recently reported that small molecule defensin-mimetic compounds discovered by Radnor, Pennsylvania-based biopharmaceutical company PolyMedix, irreversibly kill P. falciparum while sparing human red blood cells.

Plasmodium species are responsible for the nearly 500 million cases of malaria worldwide and as many as two million deaths, most of them in children.

As with antimicrobial agents, first-line malaria agents are losing effectiveness due to development of resistance to drugs by the target organisms.

Greenbaum demonstrated that PolyMedix's compounds kill P. falciparum irreversibly, meaning the cells do not recover when the agent is depleted.

Irreversible killing distinguishes a "cidal", or true killing mechanism, from a "static" mechanism that holds the infectious agent at bay while the body's immune system fights off the infection, said a Pennsylvania release.

"If we treat for 10 hours and remove the compound, the parasites never recover," notes Greenbaum. Many antimicrobial and antifungal drugs are of the static variety.

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'Alzheimer's drugs double death risk in elderly'

London (AP) :- Anti-psychotic drugs commonly used to treat Alzheimer's disease may double a patient's chance of dying within a few years, suggests a new study that adds to concerns already known about such medications.

"For the vast majority of Alzheimer's patients, taking these drugs is probably not a worthwhile risk," said Clive Ballard, the paper's lead author, of the Wolfson Centre for Age-Related Diseases at King's College London.

"Would I want to take a drug that slightly reduced my aggression but doubled my risk of dying? I'm not sure I would," Ballard said.

The research was published today in the medical journal, Lancet Neurology.

Alzheimer's disease is the most common cause of dementia and causes symptoms including aggression, delusions and hallucinations. Previous studies have shown anti-psychotic drugs, which can help control the aggression and hallucinations for a few months raise the risk of death in older patients with dementia. There are other side effects, including respiratory problems and stroke.

Ballard and colleagues followed 165 patients aged 67 to 100 years with moderate to severe Alzheimer's disease from 2001 to 2004 in Britain. Half continued taking their anti-psychotic drugs, which included Risperdal, Thorazine and Stelazine. The other half got placebos.

Of the 83 receiving drugs, 39 were dead after a year. Of the 82 taking fake pills, 27 were dead after a year. Most deaths in both groups were due to pneumonia.

After two years, 46 per cent of Alzheimer's patients taking the anti-psychotics were alive, versus 71 per cent of those not on the drugs. After three years, only 30 per cent of patients on the drugs were alive, versus 59 percent of those not taking drugs.

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Scientists closer to finding cure for cancer afflicting kids

Sydney (IANS): Researchers have edged closer to finding a potential cure for the commonest tumour afflicting young children.

Michelle Haber AM, executive director, Children's Cancer Institute Australia (CCIA), said the findings were an exciting development towards an eventual cure for this childhood cancer.

Researchers have known that the presence of multiple copies of the cancer-associated gene, MYCN, in neuroblastoma tumours is a powerful predictor of death in this disease.

It has also been known that MYCN drives the expression of many other genes including one in particular called ODC1.

"Patients whose tumours carry multiple copies of the MYCN gene have a particularly poor prognosis and new therapies are urgently needed," said Haber.

"Our findings indicate that over expression of the ODC1 gene contributes to the aggressive biology of this tumour and poor clinical outcomes, said a CCIA release.

Using a lab model of neuroblastoma, researchers tested whether inhibiting ODC1 activity with difluoromethylornithine (DFMO), a drug known to suppress ODC1 function, would improve treatment of neuroblastoma, when used in combination with conventional chemotherapeutic drugs.

"We found that the combined drug treatment prolonged tumour-free survival compared with chemotherapeutic drugs alone, suggesting that targeting ODC1 for suppression is a potentially valuable therapeutic approach," said Haber.

Source :- Scientists closer to finding cure for cancer afflicting kids

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Prevention is key to oral health

London (IANS): At this time of the year, many people consume much more food and sugary drinks than usual, neglecting dental health.

Because oral health is rarely life threatening, it can be a low priority for national governments. Yet tooth decay is one of the most prevalent health problems worldwide, with some 90 percent of people having had dental problems or toothache caused by this condition.

In low-to-middle income countries, much tooth decay goes untreated. Severe periodontitis affects 5-15 percent of most populations and oral cancer is the eighth most common cancer worldwide and the most common in men in southeast Asia.

While countries like Britain and Germany have a dentist for every 1,000 people, low-income and middle-income countries can have as few as one for every 50,000 and in sub-Saharan Africa this ratio is close to one for every million.

Rural areas are often those most in need of dentists. Although these poorer countries need more dental health practitioners, this is not practical in poor settings. Thus prevention is the key strategy, says an article in the latest issue of The Lancet.

Daily use of fluoride is the most cost-effective, evidence-based approach to reduce dental decay. Fluoridating water is a possible population-wide approach but implementation depends on a country's infrastructure and political will.

Use of fluoridated toothpastes is also effective, but cost can prohibit this. In some countries, taxes can represent 50 percent of the price of toothpaste - so governments could cut these taxes and also work with manufacturers to produce lower cost toothpaste.

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