Dental Questions: Can a dentist diagnose decay in the mouth that is not evident on an x-ray?

Yes, it is absolutely possible to diagnose decay in the mouth from a visual exam with a mirror and explorer.  Decay on the biting surfaces of the teeth can often be hiding in a pit, groove or fissure of the outer enamel layer. On a visual exam, the area can look like a dark spot in the white of the enamel or an explorer can get stuck in the cavitation. The x-ray won’t show the decay in this area if is still primarily in the enamel layer. However, once decay spreads past this first layer of defense and lands in the internal dentin layer of the tooth, it will definitely show up on an xray.

Take a look at the following pictures, taken from the same patient in the same appointment:

In reviewing the radiographs, there is no apparent decay in this patient’s molars. There aren’t any suspicious shadows or defects in the enamel and the teeth generally look healthy. 

However, a visual examination reveals the beginnings of a cavity forming in the two maxillary molars. The geography of the tooth allows the decay to be hidden as the three dimensional object is translated into a 2D X-ray. Conversely, not all pit and fissure stains are cavities. Dentists can recognise unique shapes, patterns and texture changes in teeth that differentiate staining from active decay. This further highlights the importance of the entire dental exam to make a proper diagnosis. 

CAMBRA and Preventative Dentistry

    At Thousand Oaks Family Dentistry, we tend to ask a lot of questions. Some of them are are expected (“Do you floss regularly?”), while others (“What type of water do you drink?/Do you chew gum?”) might raise some confusion. While our investigations might seem slightly tedious, they are critical to our practice philosophy and how we treat our patients. These questions are part of a revolutionary preventative dentistry strategy known as CAMBRA.

    CAMBRA, or Caries (cavity) Management By Risk Assessment is a series of weighted factors and criteria that allow dentists to quickly and effectively determine tooth decay risk. By going over your dietary habits, home care techniques and medical history, we can obtain an accurate picture of how your tooth decay will progress (or continue to stay static) in the coming years. While this isn’t a “crystal ball” looking into your smile’s future, it is the best marker we have at determining your unique oral health situation.

    This screening technique relies on a simple thought process: if your habits and lifestyle lend themselves to an acidic, dry or bacteria prone mouth environment, then you will be at a greater risk for tooth decay. While this may seem obvious, what CAMBRA does is determine which factors are the most destructive, which ones can be “treated” and which ones are based on habits or lifestyle. Using this information, we can help our patients better manage their tooth decay, ultimately resulting in fewer office visits, fillings and incidences of dental discomfort.

Once we have determined your risk for tooth decay, we can make recommend products that can help you better manage your unique risks. One of these great products is Carifree Ctx3. This mouthwash-like rinse combines pH neutralization (to minimize mouth acidity), fluoride (to rebuild enamel) and xylitol (to naturally inhibit acid-producing bacteria). We love this rinse because it targets three of the decay cornerstones outlined in CAMBRA in an easy and convenient delivery method.

    Here is an example of how CAMBRA works: A 24 year old male comes in with and is diagnosed with a cavity on one of his molars. We go over his medical history and see he is taking medications that cause dry mouth. When discussing his eating habits, we find that he is a frequent snacker and enjoys sticky, processed foods. Finally, we note that he almost exclusively drinks bottled water and sports drinks. Using CAMBRA, we can determine that his tooth decay risk is likely caused by his medication and eating/drinking habits. We then recommend that he considers cutting back on snacking and sticking to 3 meals a day, stops drinking sports drinks (when not necessary) and starts drinking more filtered water, to both counteract the dryness caused by his medication and add fluoride exposure. While we will still need to treat his current tooth decay, we have now given him the knowledge and tools to better manage his oral care in the future.

    At our office, we treat every patient as a unique individual with unique needs. This is why CAMBRA fits so well with how we perform dentistry. It is not a one-size-fits-all approach, but rather a dynamic diagnosing tool that flexes with you. We are proud to operate our office on the CAMBRA model, and are incredibly satisfied with the results our patients have seen!

Emax Lithium Disilicate Crowns

    When it comes to dental crown materials, there are many different options to suit a multitude of different scenarios. Some, like full porcelain crowns, provide excellent esthetic results. Others, such as full gold units, provide extreme durability along with desirable tooth-like physical properties. However, what options offer both beautiful cosmetic results along with enduring strength?

For many years, porcelain-fused-to-metal (or “PFM”) crowns were the cornerstone of “form meets function” in crown materials. These units are made by taking an alloy metal core and attaching a thin layer of porcelain over it, resulting in a durable tooth colored restoration. Unfortunately, this process is not without it’s downfalls. The porcelain has a tendency to crack and break between the opposing tooth and the hard metal sublayer. Additionally, the alloy substructure is extremely opaque, and prevents the overall crown from having the translucency of a natural tooth. This detracts from the overall esthetics of the final product.

While PFM crown still have a very useful place in dentistry (and are still regularly placed at our office for various reasons), modern technology has provided us with newer and more elegant solutions. Today, we can offer Emax as a means of creating a beautiful crown or bridge with long term durability.

An example of a finished Emax dental bridge (right) and crown (left)

Emax is a lithium disilicate material that combines the translucency of porcelain with incredible strength. On average, these restorations can withstand 360-400 megapascals of force before breaking. What does this mean? Essentially, you could hammer a crown made of Emax into a plywood board and pull it out without damaging the structure. This incredible resilience means that Emax can be placed in almost any location in the mouth with extreme confidence.

In terms of esthetics, Emax rivals porcelain in that it provides an incredibly toothlike translucency. One of the most obvious “tells” of a dental crown is poor transmittance of light. Crown that do not respond to ambient light like natural teeth are just as visually jarring as poor tooth shade matching. Emax offers this low opacity in conjunction with the ability to have natural artifacts “baked” into the crown’s surface. Surface lines, color gradients and staining can be added to the crown to blend it perfectly with the adjoining teeth. Overall, this step helps detract from the “chiclet gum” look that is imparted to certain crown.

Of course, Emax in only one of the excellent crown options offered at our office. While it has some great properties, it can be a poor choice of restoration depending on a number of factors. Your crown material should take into account mouth location, neighboring teeth and your personal expectations. We regularly work with a number of different materials because our patients regularly need a number of different materials. If you have any questions Emax, or any other materials we offer at our office, please let us know at your next appointment!