Abfraction.

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As we end our fourth year of dental hygiene education, we still clearly remember our first clinical experience and all the mixed emotions that came along with it. It was our first opportunity to apply everything we learned during our classroom lectures to real situations. As students, we were nervous. We would soon be identifying abnormalities that we had only seen on PowerPoint presentations in our lectures.

Quickly, our progressing clinical experiences proved indeed that the most common lesions included recession, abrasion and erosion. However, in due time, we realized we were missing one other major, but rarely identified, loss of tooth structure: abfraction. So just what is abfraction?

Abfraction is the loss of tooth structure at the cervical region from heavy occlusal forces. (1) It is easy to overlook and even misdiagnosed. Through research and table clinic presentations, we learned that not only did we as students have limited information about and experience with abfraction, so do many practicing hygienists. With this in mind, we learned that abfraction can closely resemble abrasion. Learning to differentiate the two helps properly identify the lesion, which will determine the ever-so-important treatment plan and patient education. Because it mimics abrasion, close inspection is imperative, and the proper clinical evaluations will aid in the identification and diagnosis of abfraction.

Clinically differentiating abfraction from abrasion requires a detailed comprehensive examination. When conducting the exam, it is important to understand the differences between the two (see box on this page).

In addition, causes help guide us in identifying abfraction. Causes of abfraction include excessive chewing and/or biting forces such as bruxism, erosion and corrosion; clenching of the mandible; malocclusion and tongue thrusting. These are especially important to keep in mind as we conduct the intra-/extra-oral exam, paying special attention when assessing the occlusion and temporomandibular joint movement of all patients. Any signs of these habits should alert the hygienist to delve further into the exam. Among the things to look for are

* Stress lines and enamel fracture

* Recession

* Bite and jaw alignment

* Wear facets, especially cusps of posterior teeth

* Exostosis indicative of chronic bruxism (2)

As a part of the clinical examination, communication with our patients is another key point in identifying abfraction. Questions to ask the patient include, "Do you wake with a sore jaw?" and "Have you been told that you grind your teeth during the night?" Check the occlusal surfaces of the teeth and conduct a thorough inspection of the cusps. Look to see if attrition seems excessive based on age. (3) In addition, radiographs are indicated to assess signs of traumatic occlusion and to assess bone support. Look for radiographic signs of widening periodontal ligaments. Does the cementum appear thicker? Going through this clinical exam will give the hygienist and dentist the right diagnosis. The right diagnosis will determine the proper treatment and its anticipated success.

Treatment for abrasion may include placement of glass ionomer (for its fluoride release) and composite along with patient education on home care and softer brushing techniques. However, if abfraction is misdiagnosed as abrasion, this composite will eventually fail. Occlusal load and force at cervical enamel will cause the restoration to pop out, bringing the patient back into the chair, with disappointment that the problem has not been rectified. So how what type of treatment should be rendered?

The first appropriate step in treatment may include occlusal adjustment or use of a nightguard. Eventually, once the direct cause has been eliminated, placement of glass ionomer could be the treatment of choice. (2) While it is important for us to remember that as hygienists, diagnosis is not within our scope of practice, we must conduct a process of elimination so that we can bring these signs to the dentist's attention. We are hopeful that the problem will then be corrected, allowing for successful retention of a restorative material.

Health care, including oral health care, is always changing and moving forward. To stay informed (clinically and educationally) makes dental hygienists a huge asset in any practice. But along with keeping ourselves updated with new information, it is important that we maintain an awareness of known, but underdiagnosed, conditions such as abfraction.

* Abfraction and Abrasion (2, 3)

Abfraction

* Loss of tooth structure by compression and tensile forces

* Located at the cervical region on buccal and lingual sides

* V-shaped depression at tensile forces; C-shaped depression at compression forces

* Can affect single teeth

Abrasion

* Loss of tooth structure by foreign substance (toothbrush, dentifrice)

* Located at cervical region usually only on buccal

* Scooped out depression

* Commonly affects more than one tooth, usually premolars and canines

References

(1.) Daniel S, Harfst S. Mosby's dental hygiene: concepts, cases and competencies. Lippincott Williams & Wilkins; 2005.

(2.) Rolf D. Abfraction; 2006. Available at www.dental1.org/care/dentalcondition20.cfm/33. Accessed Jun. 9, 2007.

(3.) Grippo J, Simring M, Schreiner S. Attrition, abrasion, corrosion and abfraction revisited: a new perspective on tooth surface lesions. J Am Dent Assoc 2004; 135:8: 1109-18.

As senior dental hygiene students at The Ohio State University, the authors are eagerly awaiting graduation in June of 2008 and excited to begin their professional careers in dental hygiene. Sarah Smith is planning to stay in Columbus, Ohio, to practice dental hygiene, then in the near future go on to get her master's degree in clinical hygiene. Bobble L. Tucker is going back to her home town in sunny Arizona, where she plans to practice and volunteer in community outreach for dental health. Kellie Sellers-Dicaire is looking forward to her new venture to Alaska, along with her family, where she will practice and follow her aspirations for community outreach as well. Leah Quelette is pursuing an exciting career in the sales and marketing aspect of dental hygiene and is looking forward to new experiences in the marketing field.