Cell Transplantation study shows bone growth from implanted tooth and dental pulp stem cells

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Researchers in Japan have completed a study showing that stem cells derived from deciduous canine teeth and dental pulp can be grafted and produce bone regeneration between parents and offspring. Their results are published in the current issue of Cell Transplantation (20:7), now freely available on-line.

"Bone defects can occur for a number of reasons, and autogenous bone grafting - using the patient's own bone - has been a standard approach to treatment," said study corresponding author Dr. Yoichi Yamada of the Center for Genetic and Regenerative Medicine at the Nagoya University School of Medicine. "However, considering severe invasiveness in self-donor bone sites, and the limited supply of autogenous bone, alternative donor sources are needed."

The researchers note that previous studies have shown that oral and maxillofacial dental tissues contain a variety of stem cells, such as dental pulp stem cells and stem cells from deciduous teeth. Stem cells, they note, can be easily extracted from deciduous teeth, which are routinely lost in childhood and generally discarded.

"Stem cells from human exfoliated deciduous teeth were identified as a novel population of stem cells, capable of differentiating into various cell types, such as osteoblasts, odontoblasts, adipocytes and neural cells," explained Dr. Yamada.

Their study extracted deciduous teeth from canine puppies and grafted them onto parent canine mandibles as an allograft. After four weeks, bone defects were prepared on both sides of the host mandible. The newly formed bone was evaluated at two, four and eight weeks. When compared to controls, the study group demonstrated well-formed mature bone and neovascularization.

The researchers reported that stem cells derived from dental pulp "display increased immunosuppressive activity when compared to bone marrow mesenchymal cells" and will likely have "immunosuppressive activity with potential clinical applications in allogenic in vivo stem cell transplantation, particularly for calcified tissue reconstruction."

Their pre-clinical study could pave the way for stem cell therapy in othropedics and oral maxillofacial reconstruction, concluded Dr. Yamata.

"This study highlights the promise of obtaining stem cells from unusual sources, such as teeth, and their potential benefit in familial treatments for bone reconstruction" said Dr. Julio Voltarelli, professor of Clinical Medicine and Clinical Immunology at the University of Sao Pãulo, Brazil, and section editor for Cell Transplantation. "Due to their potential to also become other cell types such as neural cells, it will be interesting to see what future studies reveal about the possible uses of these cells."

Sugar-free polyol gum, lozenges, hard candy; Nonfluoride varnishes help prevent cavities

Recommended in conjunction with fluoride for patients at high-risk for developing cavities

A multi-disciplinary expert panel, convened by the American Dental Association (ADA) Council on Scientific Affairs, issued a report this month containing clinical recommendations that sugar-free chewing gum, lozenges and hard candy including xylitol or polyol combinations, and a prescription varnish with chlorhexidine and thymol could be beneficial in preventing cavities when used as adjuncts to a comprehensive cavity prevention program which includes the use of fluoride-containing products.

The panel noted in its report that these nonfluoride options could provide an extra benefit to prevent cavities in patients at high risk for developing cavities when used in addition to products such as toothpaste, dental sealants and varnishes that contain fluoride as well as community water fluoridation and good eating habits.

The executive summary of the report entitled, "Nonfluoride Caries Preventive Agents," is published in the September issue of The Journal for the American Dental Association and is available on the EBD website. The clinical recommendations from the expert panel were reviewed and approved by the ADA's Council on Scientific Affairs.

The ADA recommends that clinicians determine a patient's risk for developing cavities by conducting a caries risk assessment, The Caries Form (Patients Ages 0-6 Years) and the Caries Form (Patients Over 6 Years) which includes completing a caries risk assessment form that can be used as a communications tool with their patients.

Nonfluoride agents

In addition to a comprehensive cavity-prevention program which includes the use of fluoride, the scientific panel recommended that clinicians consider applying a mixture of cholrhexidine-thymol varnish to the teeth of high-risk adults and the elderly every three months to reduce cavities developing in the root of the tooth.

The panel encouraged clinicians to consider advising parents and caregivers of healthy children older than 5 years who are at higher risk for cavities to chew sugar-free polyol gum after meals for 10 to 20 minutes to prevent cavities.

A polyol is a low-calorie sweetener such as xylitol, sorbitol or mannitol, which is not broken down by the bacteria in the mouth and therefore does not contribute to tooth decay. The panel also recommended that sucking xylitol-containing sugar-free lozenges or hard candy after meals may reduce cavities in children.

The panel's recommendations are based on a review of evidence from 71 published articles that described 50 randomized controlled trials and 15 nonrandomized studies to assess the effectiveness of various nonfluoride agents in preventing cavities.

ADA expert panels, Evidence-Based Dentistry

The clinical recommendations, developed by expert multidisciplinary panels convened by the ADA Council on Scientific Affairs, assessed available scientific evidence and developed practice-oriented recommendations through a comprehensive evidence-based process.

Evidence-based clinical recommendations are intended to provide dentists and other health professionals with a review of the latest scientific evidence on particular topics and are not considered a standard of care. Rather, health care professionals can consider clinical recommendations, patient preference and their own clinical judgment when diagnosing and treating patients.

Caries-Preventive Agents: Nonfluoride Caries-Preventive Agents: Executive Summary of Evidence-Based Clinical Recommendations

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In this report, the authors present evidence-based clinical recommendations regarding the use of nonfluoride caries preventive agents. The recommendations were developed by an
expert panel convened by the American Dental Association (ADA)
Council on Scientific Affairs. The panel addressed several questions
regarding the efficacy of nonfluoride agents in reducing the incidence
of caries and arresting or reversing the progression of caries.

Types of Studies Reviewed

A panel of experts convened by
the ADA Council on Scientific Affairs, in collaboration with ADA
Division of Science staff, conducted a MEDLINE search to identify
all randomized and nonrandomized clinical studies regarding the
use of nonfluoride caries-preventive agents.

Results

The panel reviewed evidence from 50 randomized controlled
trials and 15 nonrandomized studies to assess the efficacy of
various nonfluoride caries-preventive agents.

Clinical Implications

The panel concluded that certain nonfluoride
agents may provide some benefit as adjunctive therapies in
children and adults at higher risk of developing caries. These recommendations
are presented as a resource for dentists to consider
in the clinical decision-making process.

Ω

Sealants and dental caries

The authors conducted a study to survey the perspectives of dentists
regarding the 2010 American Dental Association (ADA) recommendation to seal noncavitated carious lesions (NCCLs) in children and young adults.

Methods

The authors mailed a questionnaire
to a randomly selected sample of 2,400 general dentists
(GDs) and pediatric dentists (PDs) in the United States.
The sample was chosen by the ADA’s Survey Center. The
questionnaire included two photographs of NCCLs (permanent
first molar and premolar) in a 12-year-old child. Respondents
were provided with radiographic findings and asked to
choose from several management options.

Results

In the absence of radiographic evidence of caries,
37.4 percent and 42.3 percent of GDs and PDs, respectively,
indicated that they would seal the NCCL in the molar. For
the premolar, a significantly lower percentage of GDs than of
PDs indicated that they would seal the NCCL. With radiographic
evidence of caries in dentin, less than 4 percent of all
dentists surveyed indicated that they would seal the NCCLs,
and more than 90 percent indicated that they would remove
the caries and place restorations. Less than 40 percent of
dentists indicated that they sealed NCCLs in their practice.
Conclusions. The U.S. dentists surveyed have not adopted
evidence-based clinical recommendations regarding the
sealing of NCCLs.

Practice Implications

New educational and dissemination
programs should be developed regarding these evidence-based
caries management approaches.

Ω

Implant Prosthesis Offers an Improvement Over Dentures

Filling without drilling

Researchers at the University of Leeds have discovered a pain-free way of tackling dental decay that reverses the damage of acid attack and re-builds teeth as new.

The pioneering treatment promises to transform the approach to filling teeth forever.

Tooth decay begins when acid produced by bacteria in plaque dissolves the mineral in the teeth, causing microscopic holes or 'pores' to form. As the decay process progresses these micro-pores increase in size and number. Eventually the damaged tooth may have to be drilled and filled to prevent toothache, or even removed.

The very thought of drilling puts many people off going to see their dentist, whether or not they actually need treatment. This tendency to miss check-ups and ignore niggling aches and pains means that existing problems get worse and early signs of decay in other teeth are overlooked.

It's a vicious cycle, but one that can be broken, according to researchers at the University of Leeds who have developed a revolutionary new way to treat the first signs of tooth decay. Their solution is to arm dentists with a peptide-based fluid that is literally painted onto the tooth's surface. The peptide technology is based on knowledge of how the tooth forms in the first place and stimulates regeneration of the tooth defect.

"This may sound too good to be true, but we are essentially helping acid-damaged teeth to regenerate themselves. It is a totally natural non-surgical repair process and is entirely pain-free too," said Professor Jennifer Kirkham, from the University of Leeds Dental Institute, who has led development of the new technique.

The 'magic' fluid was designed by researchers in the University of Leeds' School of Chemistry, led by Dr Amalia Aggeli. It contains a peptide known as P 11-4 that - under certain conditions - will assemble together into fibres. In practice, this means that when applied to the tooth, the fluid seeps into the micro-pores caused by acid attack and then spontaneously forms a gel. This gel then provides a 'scaffold' or framework that attracts calcium and regenerates the tooth's mineral from within, providing a natural and pain-free repair.

The technique was recently taken out of the laboratory and tested on a small group of adults whose dentist had spotted the initial signs of tooth decay. The results from this small trial have shown that P 11-4 can indeed reverse the damage and regenerate the tooth tissue.

"The results of our tests so far are extremely promising," said Professor Paul Brunton, who is overseeing the patient testing at the University of Leeds Dental Institute. "If these results can be repeated on a larger patient group, then I have no doubt whatsoever that in two to three years time this technique will be available for dentists to use in their daily practice."

"The main reason that people don't go to the dentist regularly is fear. If we can offer a treatment that is completely non-invasive, that doesn't involve a mechanical drill, then we can change that perceived link between dental treatment and pain. This really is more than filling without drilling, this is a novel approach that enables the patients to keep their natural teeth!"

Sports Dental Injuries Are No Laughing Matter

Ω

The crunch of helmets as players tangle for a loose football, the swoosh of the net as an outside jumper is made and the crack of the bat as a guaranteed double sails into right center field are awesome sounds to sports fans but for dentists, they’re reminders that a player is just one misstep away from a dental injury.

“Basketball and baseball are the two biggest mouth-injuring sports,” says Stephen Mitchell, D.M.D., associate professor in the UAB Department of Pediatric Dentistry. “And the most common injuries we see are broken, displaced or knocked out teeth, and broken jaws.”

According to a report by the U.S. Surgeon General, craniofacial injuries sustained during sporting activities are a major source of nonfatal injury and disability in children and adults, accounting for up to one-third of all sports injuries. The National Youth Sports Safety Foundation estimates that more than 3 million teeth will be knocked out in youth sporting activities this year.

The increasing participation of girls and young women in competitive sports means that they, just like their male counterparts, should know the risks of dental injuries and use additional protective gear as appropriate, Mitchell says.
Mitchell says mouth guards and helmets with face protectors are the best way for kids to avoid dental injuries while playing sports.

“If the child has a full set of permanent teeth then a custom guard can be made that will provide protection but be small enough to make it easy to communicate with teammates,” Mitchell says. “But if they still have some of their baby teeth, a custom guard is a waste of money. Parents will be better off going to the store and buying one of the guards that can be boiled and molded to their child’s mouth.”

So what should you do if despite your best preventive efforts your child still hurts his or her teeth or jaw?

If a tooth is broken or cracked, see a dentist within 24 hours, Mitchell says. If a tooth or teeth have been displaced or knocked out, Mitchell says, take the child immediately to the emergency room and to try to preserve the tooth.

“A tooth that has been knocked out needs to be back in the mouth within 30 minutes for the best chance of long-term survival,” Mitchell says. He offers these tips for preserving the tooth, which can even help past the ideal 30-minute window:
• Avoid touching the root because it can be damaged easily.
• If the tooth is dirty, hold it by the upper part and rinse it off with milk until most of the dirt is washed away. If you don't have milk, don’t clean it. Wiping it off may cause more damage.
• If your child is old enough not to swallow it, try to gently put the tooth back in its socket for the best chance of preservation.
• If you can’t get it back in the socket, put it in a cup of milk and head for the dentist or emergency room.
“We tell people to put the tooth in milk because the cells around the root are still alive after it is knocked out and milk can provide nutrients to the cells to help keep them alive,” Mitchell adds. “Do not put the tooth in water. It can cause the cells to burst and makes saving the tooth much less likely.”
Jaw injuries may be much less obvious than a broken or knocked-out tooth but they are no less serious, Mitchell says. If a child falls hard enough to cut their chin, or takes an especially hard hit, it could easily cause breaks in the jaw. In an injury such as this, a child should be seen by a doctor within 24 hours.
No matter the injury, Mitchell says caring properly for the mouth afterward is key to successful healing.
“Following an injury a child’s mouth will be sore and they will want to do everything they can to make it not hurt. But, continuing to brush their teeth and practice good oral hygiene is extremely important,” he says. “It is the same as keeping any other wound clean, the cleaner the mouth is kept, the better it heals.”Home
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Sports Dental Injuries Are No Laughing Matter
Released: 8/22/2011 5:30 PM EDT
Source: University of Alabama at Birmingham
Newswise — BIRMINGHAM, Ala. – The crunch of helmets as players tangle for a loose football, the swoosh of the net as an outside jumper is made and the crack of the bat as a guaranteed double sails into right center field are awesome sounds to sports fans but for dentists, they’re reminders that a player is just one misstep away from a dental injury.
“Basketball and baseball are the two biggest mouth-injuring sports,” says Stephen Mitchell, D.M.D., associate professor in the UAB Department of Pediatric Dentistry. “And the most common injuries we see are broken, displaced or knocked out teeth, and broken jaws.”
According to a report by the U.S. Surgeon General, craniofacial injuries sustained during sporting activities are a major source of nonfatal injury and disability in children and adults, accounting for up to one-third of all sports injuries. The National Youth Sports Safety Foundation estimates that more than 3 million teeth will be knocked out in youth sporting activities this year.
The increasing participation of girls and young women in competitive sports means that they, just like their male counterparts, should know the risks of dental injuries and use additional protective gear as appropriate, Mitchell says.
Mitchell says mouth guards and helmets with face protectors are the best way for kids to avoid dental injuries while playing sports.
“If the child has a full set of permanent teeth then a custom guard can be made that will provide protection but be small enough to make it easy to communicate with teammates,” Mitchell says. “But if they still have some of their baby teeth, a custom guard is a waste of money. Parents will be better off going to the store and buying one of the guards that can be boiled and molded to their child’s mouth.”
So what should you do if despite your best preventive efforts your child still hurts his or her teeth or jaw?
If a tooth is broken or cracked, see a dentist within 24 hours, Mitchell says. If a tooth or teeth have been displaced or knocked out, Mitchell says, take the child immediately to the emergency room and to try to preserve the tooth.
“A tooth that has been knocked out needs to be back in the mouth within 30 minutes for the best chance of long-term survival,” Mitchell says. He offers these tips for preserving the tooth, which can even help past the ideal 30-minute window:
• Avoid touching the root because it can be damaged easily.
• If the tooth is dirty, hold it by the upper part and rinse it off with milk until most of the dirt is washed away. If you don't have milk, don’t clean it. Wiping it off may cause more damage.
• If your child is old enough not to swallow it, try to gently put the tooth back in its socket for the best chance of preservation.
• If you can’t get it back in the socket, put it in a cup of milk and head for the dentist or emergency room.

“We tell people to put the tooth in milk because the cells around the root are still alive after it is knocked out and milk can provide nutrients to the cells to help keep them alive,” Mitchell adds. “Do not put the tooth in water. It can cause the cells to burst and makes saving the tooth much less likely.”

Jaw injuries may be much less obvious than a broken or knocked-out tooth but they are no less serious, Mitchell says. If a child falls hard enough to cut their chin, or takes an especially hard hit, it could easily cause breaks in the jaw. In an injury such as this, a child should be seen by a doctor within 24 hours.
No matter the injury, Mitchell says caring properly for the mouth afterward is key to successful healing.

“Following an injury a child’s mouth will be sore and they will want to do everything they can to make it not hurt. But, continuing to brush their teeth and practice good oral hygiene is extremely important,” he says. “It is the same as keeping any other wound clean, the cleaner the mouth is kept, the better it heals.”