Gingival stem cells offer potential for use in tissue regeneration

Main Category: Dentistry
Also Included In: Stem Cell Research
Article Date: 23 Jul 2013 - 0:00 PDT

 email to a friend    printer friendly    opinions   

Current ratings for:
Gingival stem cells offer potential for use in tissue regeneration

Patient / Public:		5 (2 votes)
Healthcare Prof:

The International and American Associations for Dental Research (IADR/AADR) have published a paper titled "Gingivae Contain Neural-crest- and Mesoderm-derived Mesenchymal Stem Cells." The paper, written by lead author Songtao Shi, Center for Craniofacial Molecular Biology, Ostrow School of Dentistry, University of Southern California, Los Angeles, USA, is published in the Online First portion of the IADR/AADR Journal of Dental Research.

Gingivae represent a unique soft tissue that serves as a biological barrier to cover the oral cavity side of the maxilla and mandible. Recently, the gingivae were identified as containing mesenchymal stem cells(GMSCs). However, it is unknown whether the GMSCs are derived from cranial neural crest cells (CNCC) or the mesoderm.

In this study, Shi and his team of researchers demonstrated that around 90 percent of GMSCs are derived from CNCC and 10 percent from the mesoderm. In comparison with mesoderm MSCs (M-GMSCs), CNCC-derived GMSCs (N-GMSCs) show an elevated capacity to differentiate into neural cells and chondrocytes as well as to modulate immune cells. When transplanted into mice with dextran sulfate sodium-induced colitis, N-GMSCs showed superior effects in ameliorating inflammatory-related disease phenotype in comparison with the M-GMSC treatment group.

Further research is required to understand the interaction between the neural crest cell derived and mesoderm derived gingivae mesenchymal stem cells (N-GMSCs and M-GMSCs) in terms of their functional roles in gingival immune defense and wound healing.

"The tooth and surrounding tissues are a rich source of stem cells, and this JDR manuscript demonstrates that gingivae contain highly proliferative stem cells from two different embryonic origins and that these cells exhibit distinct behaviors," said JDR Associate Editor Jacques Nör. "These results suggest that gingivae, an easily accessible tissue, are an attractive source for stem cells that can be used in tissue regeneration."

Think before you drink: Erosion of tooth enamel from soda pop is permanent

Main Category: Dentistry
Article Date: 24 Jul 2013 - 2:00 PDT

 email to a friend    printer friendly    opinions   

Current ratings for:
Think before you drink: Erosion of tooth enamel from soda pop is permanent

Patient / Public:		4.2 (5 votes)
Healthcare Prof:		5 (1 votes)
Article opinions:	1 posts

You may be saving calories by drinking diet soda, but when it comes to enamel erosion of your teeth, it's no better than regular soda.

In the last 25 years, Kim McFarland, D.D.S., associate professor in the University of Nebraska Medical Center College of Dentistry in Lincoln, has seen an increase in the number of dental patients with erosion of the tooth enamel - the protective layer of the tooth. Once erosion occurs, it can't be reversed and affects people their whole life.

"I'd see erosion once in a while 25 years ago but I see much more prevalence nowadays," Dr. McFarland said. "A lot of young people drink massive quantities of soda. It's no surprise we're seeing more sensitivity."

Triggers like hot and cold drinks - and even cold air - reach the tooth's nerve and cause pain. Depending on the frequency and amount of soda consumed, the erosion process can be extreme.

She said according to the National Soft Drink Association, it's estimated the average American drinks 44 gallons of soda pop a year. Phosphoric and citric acid, which are common ingredients in many popular sodas and diet sodas, alters the pH balance in the mouth and can cause tooth erosion over time.

"It can be more harmful than cavities because the damage causes tooth sensitivity," Dr. McFarland said. "If a tooth is decayed a dentist can fix it by placing a filling, but if a tooth is sensitive there is really nothing a dentist can do.

"Tooth sensitivity can become a lifetime problem, limiting things we like to drink and even food choices. You could crown all your teeth but that is costly and a rather extreme solution," Dr. McFarland said.

"It hurts to consume cold and hot foods and beverages. Some of my patients tell me when they go outside in the winter they don't open their mouth or the cold air causes pain."

In addition, a significant number of scientific studies show a relationship between the consumption of soda and enamel erosion and cavities.

Dr. McFarland said it's best not to drink soda at all, but she offers tips for those who continue to drink it.

• Limit consumption of soda to meal time
• Don't drink soda throughout the day
• Brush your teeth afterwards -- toothpaste re-mineralizes or strengthens areas where acid weakened the teeth
• If tooth brushing is not possible, at least rinse out your mouth with water
• Chew sugar free gum or better yet, gum containing Xylitol.

Modern dentistry may benefit from discovery of an evolutionary compromise for long tooth preservation

Main Category: Dentistry
Article Date: 27 Jul 2013 - 0:00 PDT

 email to a friend    printer friendly    opinions   

Current ratings for:
Modern dentistry may benefit from discovery of an evolutionary compromise for long tooth preservation

Patient / Public:		4 (3 votes)
Healthcare Prof:

Researchers at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, and the Senckenberg Research Institute in Frankfurt am Main, Germany, have conducted stress analyses on gorilla teeth of differing wear stages. Their findings show that different features of the occlusal surface antagonize tensile stresses in the tooth to tooth contact during the chewing process. They further show that tooth wear with its loss of dental tissue and the reduction of the occlusal relief decreases tensile stresses in the tooth. The result, however, is that food processing becomes less effective. Thus, when the condition of the occlusal surface changes during an individual's lifetime due to tooth wear, the biomechanical requirements on the existing dental material change as well - an evolutionary compromise for longer tooth preservation.

First, the researchers created 3D digital models of three gorilla lower second molars differing in wear stages. In a second step they applied a Software tool (Occlusal Fingerprint Analyser) developed in the Senckenberg Research Institute to precisely determine tooth to tooth contacts. They then used an engineering approach, finite element analysis (FEA), to evaluate whether some dental traits usually found in hominin and extant great ape molars have important biomechanical implications.

The results show that in unworn and slightly worn molars (with a well-formed occlusal relief that is most effective for processing food) tensile stresses concentrate in the grooves of the occlusal surface. In such a condition, the different crests of a molar carry out important biomechanical functions, for example, by reinforcing the crown against stresses that occur during the chewing process. Due to a loss of tooth tissue and a reduction of the occlusal relief the functionality of these crests diminishes during an individual's lifetime. However, this reduced functionality of the crests in worn teeth is counterbalanced by an increase in contact areas during tooth to tooth contacts, which ultimately contributes to a dispersion of the forces that affect the occlusal surface.

This suggests that the wear process might have a crucial influence in the evolution and structural adaptation of molars enabling to endure bite forces and to reduce tooth failure throughout the lifetime of an individual. "It seems that we observe an evolutionary compromise for long tooth preservation. Even though worn teeth are not as efficient they still fulfill their task. This would not be the case if they were lost prematurely", says Stefano Benazzi of the Max Planck Institute for Evolutionary Anthropology. He adds: "Tooth evolution and dental biomechanics can only be understood, if we further investigate tooth function in respect to the dynamic changes of tooth structures during the lifespan of individuals".

"The results have strong implications for understanding the functional biomechanics of dental traits, for deciphering the evolutionary trend of our masticatory apparatus and might have important implications in modern dentistry for improving dental treatments", says Jean-Jacques Hublin, director of the Department of Human Evolution at the Max Planck Institute for Evolutionary Anthropology.