Filling a gap using Minimal Intervention Dentistry By: Geoffrey M. Knight, BDSc, MSc, MBA, FICD

The placement of reinforcing fibers into direct resin bridges has enabled dentists to give patients a predictable prosthesis that has minimal biological and fiscal costs and a wide range of future treatment options. A cantilever design is more predictable, easier to place and facilitates flossing.

Often considered as a stopgap while a more permanent replacement is prepared, a disciplined adjustment of the occlusion, with the removal of all protrusive and lateral interferences, will result in a long-term restoration. Figure 1 shows resin bridges on the lateral incisors that have been in place for 30 years.

This shows the placement of a cantilever bridge replacing a missing upper right central incisor (Fig. 2).

Figure 1

Figure 2

Tooth preparation was restricted to an undercut slot on the lingual surface of the adjacent central incisor, extending two-thirds the width of the lingual surface and about 1mm in diameter. This conservative preparation is essentially contained within the enamel and is simply repaired if alternative treatment solutions are pursued in the future.

A 1.5mm everStick® fiber was sectioned to fit into the slot and extend about two-thirds into the pontic width. The fiber was then sectioned longitudinally to form a wedge shape over one third of its length. The unset fiber was then tried into the lingual slot to determine its compatibility with the preparation (Fig. 3). The abutment was then etched with 37% phosphoric acid for ten seconds, and dried with oil free air. Dentin bond was applied followed by a small amount of micro hybrid composite resin. The fiber was then puddle into place and cured. The remaining exposed portion of the fiber was covered with a micro hybrid resin and cured.

The gingival floor was formed by placing a metal sectional matrix on the gingival base and applying a resin modified glass ionomer cement. This inhibits plaque on the pontic, protects the abutment from caries and facilitates contouring of the gingival aspects of the pontic with slow speed diamonds and abrasive discs.

The pontic was built up using a layering technique with micro hybrid resins followed by an overlay of an incisal shade microfill resin that can be polished to a high sheen and will maintain a luster for many years.

Figure 3

Figure 4

One week later the patient was recalled to confirm there were no occlusal interferences and final polishing of the microfill resin (Fig. 4).

With experience, these bridges can be placed in around 40 minutes, for the same fee as a single tooth chrome denture, offering substantial savings to patients and productivity benefits for practitioners. Dentists who offer their patients fiber reinforced direct resin bridges as a treatment option will find that they are both a useful practice builder and a rewarding way to practice dentistry.

Geoff Knight, BDSc, MSc, MBA, FICD, is a general dentist from Melbourne, Australia. A noted lecturer, Geoff will be presenting seminars in Missouri and Pennsylvania on minimal intervention techniques during September. He’ll be in St. Louis Sept. 26 and Philadelphia, Sept. 27. For additional information phone 1-800-554-6394 or fax your request to 800-552-0222. Visit www.dentalk.com.au.