Evaluating Lesser-Known Methods
Glass ionomers offer an effective but often undervalued treatment option
Jeff Brucia, DDS
Evaluating and choosing what to implement from the constant stream of technical advancements unveiled in the industry each year can prove to be an exciting, yet tedious task. Throughout my tenure in general practice, I have learned the importance of adopting a well-rounded approach to employing new techniques and materials. Determining the best course of treatment for each patient involves finding a balance between the old and the new, which often requires practitioners to compare the efficacy of widely accepted material resources with those that receive less mainstream attention. The lack of attention given to glass ionomers in restorative dentistry is a prime example of this.
Failure to take a comprehensive approach to material selection can lead practitioners to undervalue the quality of valuable alternatives. Oftentimes, this filters into education. Glass ionomers are not covered to the same extent as other restorative materials in the curricula offered by most dental degree programs in North America, which has decreased both the frequency of their use in practice and the range of problem-solving options available for doctors to treat their patients. Arguments against glass ionomers include that they are not as esthetic, are weaker, and can be harder to handle when compared with other materials. However, these undesirable features should not completely negate the significant advantages to the use of glass ionomers. I believe that they are high-quality materials that should be considered for practices at any level.
Initially introduced in the early 1970s, glass-ionomer cements are one of the few classes of materials that chemically bond to the hydroxylapatite of the tooth, creating a fusion that is unsurpassed by many other restorative materials.
Although composites are typically the direct restorative material of choice in North America, they do not perform well in compromised oral environments. By comparison, the glass ionomers available today are the optimal choice when treating patients with existing risk factors such as a high caries rate, poor diet, and poor hygiene. For example, I will consider glass ionomers as a viable treatment option if a patient is experiencing saliva dysfunction associated with medical therapy or if there is an uncontrollable lower pH in the oral environment, both of which typically lead to an increased rate of caries.
I highly recommend the use of glass ionomers for patients who present with a symptomatic tooth for which a definitive diagnosis is unclear. In these instances, a glass ionomer can be a great tool to help with the diagnosis. For internal remineralization therapy cases in which chasing deep decay could introduce additional trauma to the nerve, glass ionomers allow for the potential remineralization and repair of the tooth without mechanical exposure or trauma.
In addition, glass ionomers are useful for everyday definitive restorations, such as those that require the "open sandwich" or "closed sandwich" technique. The open sandwich technique is indicated for any preparation that has margins that have been extended past the cementoenamel junction, such as with deep Class II or Class V lesions. In these cases, I tend to layer a glass ionomer or a resin-modified glass ionomer as my deepest increment, which elevates the deepest margins to a more manageable and controllable area. When composites are used in these circumstances, patients may experience sensitivity and more rapid and frequent recurrent decay under the plastics. Using glass ionomers as the first increment in a closed sandwich technique, without extending the material to the cavosurface, allows for a great reduction in sensitivity, a cariostatic layer that helps to slow recurrent decay, and a low modulus barrier to absorb shock and stress.
The advantages of using glass ionomers discussed herein only scratches the surface of the benefits they can provide in daily practice. Although the provision of information and research accompanying the development of new products and treatments will continue to drive the quality of service we provide to our patients, I urge you to consider incorporating lesser-known methods by evaluating them with a fresh perspective.
About the Author
Jeff Brucia, DDS, owns a private practice in San Francisco, California, that offers all aspects of restorative dentistry, including basic maintenance, general restorative therapy, and advanced full mouth reconstruction.