Tips & Tricks
A good case for the OVC includes any structurally compromised posterior tooth, in need of full occlusal coverage. Generally, any case where the McDonald Matrix Band can be retained in a stable position is suitable.
To stabilise the McDonald Matrix Band during placement, you may wish to use the wooden wedge technique. To see a video of this technique – click here.
Note: If you have a plunging opposing cusp, you will need to re-contour it first.
For more visual examples of OVC clinical cases, please see our case studies.
The key to prepping teeth for the OVC is to achieve enough occlusal reduction. Use the Occlusal Reduction Guide to check for adequate occlusal reduction.
Prepare the tooth with a round diamond bur of at least 1.2 mm diameter, followed by yellow strip tapered round-end diamond bur to remove sharp edges and polish the prep. Bevel the margins for better bonding, shade blending and easier matrix application.
Have questions about the removal of sound cusps and preserving tooth structure? Here is an article on compression dome theory that explains why this might produce a stronger overall restoration.
It is important to check the occlusal clearance before starting the OVC customisation. Allow at least 1 mm of clearance in the central fossa and 1.5 mm at the cusps and marginal ridges. OVC Occlusal Reduction Guides (which are the same thickness as the hard occlusal layer of the OVC) are supplied to confirm the minimum required clearance is achieved.
The Occlusal Reduction Guide can be covered on both sides with a coloured occlusal indicator spray such as Bausch Arti-Spray® to aid high spot identification. Place the sprayed Occlusal Reduction Guide over the dried prep and get the patient to gently bite. This will leave a coloured mark on the high spots that need further trimming.
Correct vertical height and positioning can be achieved through the use of the Occlusal Seating Guide, which is custom-made by our lab technician based on your patient’s tooth impression.
The aesthetic appeal of the OVC can be enhanced by staining with coloured resins following the manufacturer’s instructions. The following video talks about OVC colouring and opacity.
The best way to speed up the overall OVC procedure is to try to prevent as much polishing work as possible. To do this, we recommend the following:
After you are satisfied with the seating and occlusal position of the OVC, spot cure to set the occlusal dimension of the OVC, leaving the outsides pliable. To spot cure, use the spot curing tool.
After spot curing, the occlusal dimension will be fixed but the excess uncured material will extrude from the band.
We recommend clearing away as much of this excess uncured material as possible with a fine instrument such as the IPC Off Angle Short Composite Instrument from Cosmedent.
After clearing away the excess material, you can either fully cure and move to polishing, or you may prefer to use Dr Terry Wong’s method, whereby he removes the matrix band and uses a smoothing pad to smooth margins and reduce finishing time prior to curing. In the below video, Dr Wong talks you through his favourite polishing tips.
Before polishing and finishing, please remember to fully cure the OVC from all sides. Use your preferred burs, disks and polishers and then, if desired, a soft brush with polishing paste such as Cosmedent Enamelize for high shine.
Small localized dark areas on the prep, such as an amalgam tattoo or dark dentine spots, can shine through the restoration due to the high translucency of the material. To prevent this from happening, it is advisable to bond a white opaque flowable liner over the dark areas before OVC adaptation.
Fresh composite adaptation and excess removal can be done more easily with a sharp carving instrument.
It is worth spending a few extra moments to carve the proximal marginal ridges before curing as these are difficult to get right after the composite has cured.
After polishing check the mesial and distal contacts. Check for occlusal contacts in both central occlusion and lateral excursions. It is important to check for lateral excursion contacts and remove them to preserve the integrity of the restoration and for patient comfort.