If you have silver fillings that are over 15 years old, you probably have serious tooth damage or severe, undetectable decay. There is little doubt that these fillings should be replaced with either crowns or tooth-colored fillings. If you have silver (mercury) fillings which are less than 15 years old, you will probably need to get them replaced by the time they turn 15. If they are diagnosed to be defective by a clinical and radiographic examination, you would be wise to replace them before any further decay or damage is done to your teeth.

Dr. Parviz Azar-Mehr, a Prosthodonist and Professor of Clinical Dentistry at the University of Southern California, explains why these silver or mercury amalgam fillings can be detrimental. "Amalgam is metal, therefore it is radio opaque (X-Rays cannot go through it). Consequently if there is decay under the amalgam filling, it may not show on the X-Ray."

That can lead to problems that are even worse than the original cavity the amalgam was meant to treat. Amalgam tends to cause cracks in the tooth structure around the metal filling. If the cracks begin to break, a root canal or extraction will be necessary.

For many decades, amalgam fillings offered excellent restorative qualities compared to the only alternative, which was extraction. Now, dentists like Dr. Azar-Mehr can use tooth-colored fillings. These are more beneficial because they are bonded onto your teeth, and they are more esthetically pleasing because your smile will be all white and no one will know you have ever had a cavity.

Dr. Azar-Mehr is a dental specialist with postdoctoral training from London University, New York University and the University of Michigan. Dr. Azar-Mehr has taught dentistry for over 25 years. Presently, Dr. Azar-Mehr teaches in the advanced Prosthodontics at USC School of Dentistry and his private practice is in Los Angeles, California.

Mouthwash, breath mints and gum are the common agents we think of when we want to fight bad breath. We tend not to think of technology. But one Southern California dentist is using advanced technology to identify levels of odor causing bacteria in the mouth, which helps determine the cause and subsequent treatment of bad breath.

In his private practice, Dr. Parviz Azar-Mehr (http://www.azarmehr.com), Clinical Professor at USC School of Dentistry, uses the Halimeter® to scientifically detect the levels of volatile sulfur compounds (VSC) caused by bacterial growth. Measuring VSC accurately and properly is vital for effective diagnosis and treatment of bad breath.

Persistent bad breath, or halitosis, not associated with smoking or eating certain foods, is almost always a symptom of dental problems, most commonly gum disease. In rare cases, halitosis can be a symptom of more serious general health problems like a local infection in the respiratory tract, chronic bronchitis, diabetes, and even liver or kidney problems, according to the American Dental Association.

Mouthwash won't cure gum disease or liver problems. So if you can't tell what's causing the odor by the smell, getting an accurate VSC reading from the Halimeter® may be the better way to fight halitosis.

Parviz Azar-Mehr MDM, is a Prosthodontist and Professor of Clinical Dentistry at the University of Southern California. Dr. Azar-Mehr is a dental specialist with post doctoral training from London University, New York University and the University of Michigan. Dr. Azar-Mehr has taught dentistry for over 25 years.