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.

Sometimes additional matrix stabilisation can be achieved by elevating the margins using the OVC Wedges that are in the kit.  See a video showing deep margin elevation.

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.

Replica-Moving-gif bausch_arti_occlusion_spray

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.

Occlusal Seating Guide

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.

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.

Nonstick Composite Instrument

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.

Frequently Asked Questions

FAQ’s

Many of our customers complete the OVC in around 30 to 50 minutes, including prep. When first starting out with the OVC, it is expected to take longer and we suggest adding time to your appointment to prevent un-needed stress. Generally, we suggest that it takes around 5 OVC procedures before a dentist is proficient in the procedure.

Training is not mandatory, though it is highly recommended that you attend a physical or online training session with one of our product specialists. It is important to us that you feel confident and supported so you have the opportunity to be successful with the OVC.

As with any new technique, the OVC does require some degree of learning before you will be proficient. A great place to start is our videos section. Please view our online videos that show the technique.

If you’d like to arrange more personalised training, you can book a one-on-one training session with a product specialist. Please click here to reserve a time.

Yes. We offer free one-on-one online training sessions. Depending on your location, we also host regular CPD events. For dental offices or groups of multiple dentists, a lunch and learn event or similar may be possible – please contact us to discuss.

Many of our customers simply include the OVC option as part of their everyday crown explanation, covering the pros and cons of each solution and their associated costs.

Dentists who actively talk about all of the options are those that notice an uptake both in OVC acceptance and also in traditional crown acceptance.

There are many clinical situations where the One Visit Crown is the perfect compliment to your practice.

Converting large fillings to OVC’s – Often a patient presents with a tooth that needs to be heavily filled or crowned. The OVC can be a more affordable option for these patients.

As an alternative option for a crown or onlay – The OVC is an ideal full coverage restorative option for many patients, who appreciate the more efficient procedure.

For financially challenged patients – The OVC is a great option for patients that need a full coverage restoration but struggle to afford the treatment.

Technical FAQs

Both layers of the OVC are made of 73% zirconia filled hybrid-ceramic.

The occlusal layer is fully heat-cured with the occlusal anatomy custom-made for your patient. The under-layer is uncured, allowing you to adapt it to any preparation.

OVC hybrid-ceramic has a flexural strength of 146MPa. It is strong, yet flexible, and is kind to opposing dentition. It has a C-factor of 1, so shrinkage vectors are minimal.

Achieving tight interproximal contacts every time can be very technique sensitive. Depending on your preferred technique and use of wedges and separating rings, there’s a number of ways to get a tight contact. We will cover a series of tips and techniques below:

Our most recommended method is creating strong separation using a separating ring such as the original Garrison Composi-Tight ring. View our videos section to see how this works.

Clinical Tip: Be aware of the balloon effect when pressing the OVC into the band

Please be aware that when you press the OVC into the matrix band it applies equal lateral pressure, like a balloon.  This tends to force the band into a circular shape. With the premolar, we get a helpful effect.

Balloon effect helpful

On a lower molar this is unhelpful, as it tends to try to convert an oval shape into a circular shape. This pushes out lingually and inward inter-proximally.

Balloon-effect-unhelpful

To minimise the impact of this “balloon effect”, you can cut a dress-maker’s dart on the lingual size.  This relieves the pressure.  You can either place the dart towards one end or centrally on the lingual side.

Dressmakers dart tight contacts with McDonald Matrix Band

In most cases, deep cavity defects are cured in layers using standard procedures before the OVC is placed. Contraction issues are small since the C-factor is only 1. These are even further reduced by spot-curing the centre of the OVC first. By spot-curing the centre, any shrinkage can draw additional material from the surrounding uncured composite, while pulling the crown towards the tooth. This reduces internal stresses. The final cure should only be curing the periphery of the OVC and not the centre.

Spot-curing the core of the uncured composite stabilises the crown in the vertical dimension, allowing you to trim the uncured composite from the peripheral surfaces easier. This reduces the finishing time.

You only need to cure long enough to stabilise the OVC and the time will depend on the power of your curing light. Too much curing will make it hard to trim the periphery of the OVC.

It’s a very simple process – follow these easy steps:

  1. Remove excess composite with diamond or carbide burs of medium grit.
  2. Use fine grit to smooth off the surface.
  3. Use appropriate polishing discs.
  4. Use a soft brush with polishing paste.

If you like, you can use isolation devices such as a rubber dam or an Isolite System for some parts of the procedure. However, you will need to remove the isolation device at times. For example, when checking the occlusal clearance with the OVC Occlusal Reduction Guide and when checking the vertical position of the OVC by getting the patient to GENTLY bite on it. Alternatively, you can use OptraGate from Ivoclar to improve access and help with isolation.

In most cases, the OVC will cater for preparations with a maximum of 3mm occlusal clearance. If deep areas are present (more than 3mm when referencing the adjacent tooth), it is better to build up the prep.

Absolutely. In some cases, it may be possible to surround the tooth with the McDonald Matrix Band. From here you can do a normal build up in the sub-gingival area, sufficient to be able to apply the OVC. Use traditional build-up techniques to stabilise the prep as you would with a regular crown. The OVC Wedges are very useful for sub-gingival build-up.

If needed, the occlusal contacts are easily adjusted with a fine grit diamond bur with generous water spray. You may need to adjust the opposing tooth if it has a plunging cusp. The trimmed areas can be further polished with yellow band diamond polishing burs, followed by your preferred ceramic polishing system.

Not necessarily. If the interfaces are left untidy and not polished properly when the OVC is placed, there is a possibility of staining in the future. If this does happen, the crown can be easily polished at a recall visit.