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.

Below are resources that will help you decide if a case is suitable for the One Visit Crown (OVC):

See a PDF with examples of OVC clinical indications showing ideal OVC case examples.

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.

For visual examples on prepping teeth for OVC procedures – click here for a PDF showing clinical case prep examples. 

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 best way to speed up the overall OVC procedure is to shape and carve the uncured composite rather than trimming cured composite.

In particular, it is especially 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.

To do this, we recommend the following:

After you are satisfied with the seating and occlusal position of the OVC, spot cure to stabilise the OVC, leaving the periphery uncured. 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 removing the excess material, you can carve the marginal ridges then light cure while masking the buccal side with the edge of the SpotCure instrument . This leaves the buccal composite uncured so that you can shape it.  Undo the band or cut off the orange toggle to gain access to the buccal surface.

You may prefer to use Dr Terry Wong’s method, uses a smoothing pad to smooth margins and reduce finishing time prior to curing.

Before polishing and finishing, please remember to fully cure the OVC from all sides.

During the final cure, be aware of the heat emitted by your curing light and cool the tooth with air/water spray if the tooth is getting hot.

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.

Remember that when you apply bonding agent to the tooth prep and air dry, it tends to splatter and coat the inside of the matrix band.  It then bonds to the OVC and the band is virtually impossible to remove unless you DEBOND the band first.  Debond the band by sliding a fine instrument interproximally between the band and the OVC.  Approach from the buccal side.  As you keep pressing the band will pop free from the lingual side of the OVC. Often you need to prise the band away both mesially and distally before it will “pop”.  Once popped, it can be pulled with tweezers from the lingual side.

If the contact is nice and tight the band needs to be wiggled out. Note that “over-tight” contacts resolve themselves within 24 hours by the neighbouring teeth moving (orthodontically). Remember that we are talking about 20-50 microns of movement. We recommend that you tell the patient that you have done a really good job getting the contacts tight and ask them to floss it the following day and make an appointment if it can’t be flossed.

Inter-proximal stripping of a very tight contact with a diamond strip is difficult, probably unnecessary (see above) and you can over do it, leaving an open contact point. It is better to leave it and deal with it if the patient still has a problem a week later. (In Dr Simon McDonald’s experience, he has never had a patient complain of an over tight contact, a day or so later).

Check for occlusal contacts interference 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.

The aesthetic appeal of the OVC can be enhanced by staining with coloured resins following the manufacturer’s instructions.

Frequently Asked Questions

FAQ’s

Many of our customers complete the OVC in around 30 minutes, including prep. When first starting out with the OVC, it is expected to take longer and we suggest adding extra time to your first case appointment to prevent un-needed stress. Allowing 60-90 minutes is suggested. Generally, we suggest that it takes around 3-5 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 call us on 0800 680 0636 to arrange this.

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.

For NHS patients you can state that it is made in the UK, it is a tooth coloured, minimally invasive crown. This is a much healthier and longer-lasting option than a large filling or cheap, poor quality, imported crowns.

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.

You can state that OVC Private-Premium is made in the UK, it is a tooth coloured, minimally invasive crown. This is a much healthier and longer-lasting option than a large filling or cheap, poor quality, imported crowns.

The differences between the Private-Premium OVC and the NHS-Standard version are;

  • OVC Premium is aesthetically superior with a longer lasting gloss finish
  • OVC Premium is more durable than the standard version
  • OVC Premium is made from a higher quality material.

There are many clinical situations where the One Visit Crown is the perfect compliment to your practice. We’ve compiled a tip sheet – PDF OVC Clinical Indications.

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

The preferred method is shown in this video. We strongly recommend that you watch this BEFORE you do your first case.

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.

The most important point is to do most of the shaping before light-curing.  Once it is set, the process is identical to finishing any other composite restoration.

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.

Yes, absolutely.  You can place the Occlusal Reduction Guide inside the Seating Guide to ensure that you have sufficient occlusal clearance.

One Visit Crown Occlusal Seating Guide with Rubber Dam Rhondium OVC Occlusal Seating Guide with Rubber Dam

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

The OVC Wedges are very useful for sub-gingival build-up. Click here for a PDF guide of instructions.

You can also build up one or more cusps by hand and once this is done, you can usually get the band on.
Once the band is one and stable, the process is the same. Note than 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.

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.