How to prepare subgingival cavities before placing the One Visit Crown

Often dentists will be faced with preparing teeth that have subgingival margins or deep cavities below the gum line. These can be tricky - here are some tips.

This article will be broken down into two sections.   

Section 1 - Subgingival margins with the OVC Wedges

Section 2 - Subgingival margins with the McDonald Matrix Band.   

Section 1 - Subgingival margins with the OVC Wedges

The OVC Wedges are anatomically shaped to follow the natural curve of the tooth. They come in both a left and right version for mesial or distal placement, and are an ideal tool for deep margin elevation (DME).

Note:  The OVC Wedges come in both left and right.  These are included with your OVC4 case.  You can specify what sizes you'd like or if you'd like to get extra wedges on your prescription form.  

The Green is Medium Sized

The Blue is Large Sized

wedge_pairs

How to use the OVC Wedge and Garrison ring to build up subgingival cavity

Case One

01-Pre-300x194 02-Wedges-300x194 03-Etch-300x194
A. Prep tooth. B. Insert OVC Wedges. C. Etch and bond.
     
04-Build-up-300x194 05-Remove-wedges-300x194 06-Place-band-300x194
D. Complete the deep margin elevation using composite. E. Remove OVC Wedges. F. Place McDonald Matrix Band and complete OVC procedure as normal. 

 

 Case Two

Radiograph-before-small-300x194 Prep-deep-box-no-gap-300x193 Pre-opp-filled-300x194
A. Radiograph prior to treatment. B. Tooth prepped and large OVC Wedge inserted. C. Deep box elevated with composite.
     
Prep-ready-for-band-300x193 One-Visit-Crown-OVC3-after-from-top-300x194 Radiograph-after-small-300x194
D. Ready for McDonald Matrix Band placement. E. OVC after finishing, polishing and staining. F. Final radiograph.

Please note: The orange wedge pictured in the above case is called the "Stretch Wedge"this product has been discontinued.  

Take away these subgingival case studies in a PDF Click here. 

Section 2 - Subgingival margins with the McDonald Matrix Band.   

 The below video by Dr Adam Doudney talks you through the process of deep margin elevation using OVC Wedges on a typodont tooth model - then placement of the McDonald Matrix Band. 

The key deciding factor is “can you get the McDonald Matrix Band on and retained in a stable position?”.

Once the band is on and stable, you can  move onto the next steps of the OVC proceudre.  

Note that deep areas need building up and curing before placing the OVC. If you don’t do this, you risk having uncured composite beneath the OVC.

These types of cases should only be attempted after you have become proficient with the procedure.

VIDEO - Dr Terry Wong discusses deep margin elevation @ 1:43