July 30, 2014
Dr. John Garrison Explains: Tofflemire vs. Sectional
Why is a sectional matrix better than a Tofflemire-style matrix?
The Tofflemire style system fails to replicate the proximal anatomy. Looking at the band from the side, the band is flat. This causes the contact area to be pushed high toward the marginal ridge of the adjacent tooth. The proximal contacts are usually missing or very light and pointed. This often causes a premature occlusal contact in the marginal ridge area. The proximal contact is often lost while adjusting this. Furthermore, the marginal ridge will be subject to fracture because of the pointedness of the contact and lack of restorative material gingival to the contact. The flatness of the band creates a large triangular food trap gingival to the contact. Lastly, the Tofflemire band is in the Tofflemire retainer. In trying to create a cervical seal the Tofflemire band must be tightened which inherently pulls the band closer to the preparation and farther away from the contact area.
Sectional matrix systems typically use a band that is punched in three dimensions replicating the proximal anatomy. Once the band is placed, wedged, and the separating ring is placed, the band can be burnished. The sectional nature of the band allows the band to simply be pushed towards the contact area without the rebound that happens in a Tofflemire system. The rounded nature of the band allows a broad proximal contact to occur in the contact area. Furthermore, the same rounded nature allows more restorative material to exist gingival to the contact area thereby strengthening the restoration. Lastly, because the contact is well below the marginal ridge there is no fear of losing the proximal contact when adjusting the occlusal contact in the marginal ridge area.
John Garrison DDS went to the University of Michigan Dental School and practiced dentisty for over 25 years.
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