Tips & Tricks

The ideal case for an OVC3 is any case where the McDonald Matrix Band can be retained in stable position. Sometimes additional matrix stabilization can be achieved by elevating the margins using the OVC Wedges that are in the kit. If you have a plunging opposing cusp, you will need to re-contour it first. Any structurally compromised posterior teeth, in need of full occlusal coverage, are good cases for the OVC3.

For visual examples please see our case studies.

It is more accurate to measure the mesial-distal distance once the tooth is reduced and the contacts are removed. Another option is to take a bite registration impression at initial consult and use a Selector Key to measure the impression.

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.

It is important to check the occlusal clearance obtained before starting the OVC3 customization. Allow at least 1 mm of clearance in the central fossa and 1.5 mm at the cusps and marginal ridges. OVC3 Replicas are supplied to confirm the minimum required clearance is achieved.

The Replica 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 Replica 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.

The aesthetic appeal of OVC3 can be enhanced by staining with coloured resins following manufacturer’s instructions.

Before polishing and finishing, please remember to fully cure the OVC3 from all sides. Use your preferred burs, disks and polishers and then, if desired, a goat hair 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 the OVC3 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.

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

Product FAQ’s

Many of our customers complete the OVC3 in around 30 to 50 minutes, including prep.

The procedure is easier than a MODBL composite restoration.  Please view our online videos that show the technique.

If you’d like to arrange a one-on-one training session please contact us.

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

When you are doing your first case it is a good idea to explain the usual traditional crown options and also explain that you like to keep up with the latest technology and have come across a new technique (the OVC3) that can be done in one visit. Then ask if the patient would mind if you did your first case for them. Maybe you can offer a special discount. By doing this you are being totally honest with your patient. For your first case it is a good idea to allocate one hour for the appointment and make it before lunch or at the end of the day.

Many OVC3 dentists simply include the OVC3 option as part of their everyday crown explanation, covering the pros and cons of each solution and their associated costs.

To watch videos of other dentists explaining how they present the One Visit Crown to their patients, visit our blog post: how to present the One Visit Crown to your patients.

The OVC3 is a quality alternative to an expensive CAD/CAM or lab made crown or a large composite filling. The OVC3 is more efficient and therefore allows you either significantly increase your hourly productivity or allows you to be generous with your financially challenged patients.  In the USA, many dentists do the OVC3 under dental insurance or offer the treatment privately at any price they choose.

The OVC3 also makes an emergency, same day crown a possibility without a CAD/CAM.

The OVC3 comes in 5 sizes for each posterior tooth type (upper and lower premolars and molars).

Each OVC3 Case contains everything you need for a single procedure.

The Semi-Indirect method requires a separating agent. Rhondium recommends and sells two types:

Rubber Sep

  • Advantages: This is our first choice because the OVC3 is easier to remove from the tooth after curing and the Rubber Sep itself is easier to remove from the intaglio side of the crown and the tooth surface.
  • Disadvantages: It contains latex and is unsuitable where a latex allergy is present. It also smells like latex but this can be ameliorated by following the usage instructions below.
  • Usage: Place a very small amount in a Dappens dish, or wax-paper pad and then use a very small amount on a Micro-brush to apply to the tooth and then gently air-dry. A second coat can be used if necessary. If too much is applied to the tooth, it takes longer to dry. Do not use the brush supplied inside the bottle to apply Rubber Sep to the tooth.

Pro-V Coat

  • Advantages: This product does not have any smell.
  • Disadvantages: It is more difficult to remove the OVC3 after curing as the Pro-V Coat acts like a weak glue. It is also harder than Rubber Sep to remove from the intaglio surface of the crown and the tooth. Failure to remove all traces of the separating agent naturally will adversely affect the bond strength of the luting cement.
  • Usage: Pro-V Coat is best applied with the Centrix Caries Detector Micro-brushes as the blue stain changes the colour of the Pro-V Coat, making it easier to see. Apply a thin coat and air-dry. A second layer may be required.

Technical FAQs

Both layers of the OVC3 are made of 73% zirconia filled hybrid ceramic. The occlusal layer is fully heat cured with the occlusal anatomy pre-formed. The under layer is uncured, allowing you to customize it to any preparation.  OVC3 hybrid ceramic has a flexural strength of 146MPa.

Direct Method

The procedure mirrors that of an MOD composite restoration with a few refinements.  We recommend a two-stage process to get tight contacts.

  1. After placing the McDonald Matrix Band, check the margin seal. These bands can be tightened more than other bands and usually create a near perfect marginal seal. If there is a gap anywhere between the band and the tooth, then close it using either the Rhondium Stretch-Wedges or any other wedge of your choice.  Note that the Stretch-Wedges are great for closing the gap on the mesial of the upper pre-molar.  Apply your preferred etch and bond. The purpose of the next stage is to tack the band in close approximation to the neighbouring contact points using flowable resin. Burnish the contact areas. Then place either a small amount of composite or flowable resin around the margin of the proximal box. Hold the matrix band tightly against the neighbouring contact point with a hand-instrument like a ball-burnisher and cure.  Ensure that the composite or flowable is below the contact point.  If the contact point is covered with composite, you won’t be able to complete stage two below. This process closes the “proximal triangle”.
    Proximal-triangle
  2. Pull very firmly on the Stretch-Wedges, pulling the wedge further into the interproximal space. A regular wooden wedge or Master Wedges can also be used, but these must be pushed in very firmly to cause temporary separation. Re-burnish the contact areas to make allowance for the gap created by separating the teeth.

The OVC3 can then be placed into the McDonald Matrix Band. With this method, you can reliably get tight contacts when the OVC3 is placed.

Clinical Tip: Please be aware that when you press the OVC3 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 minimize 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

There are occasions when you do everything right and you still get a poor contact. Not to worry! You can recover using a “Clear Metal” sectional matrix system such as the Dentsply Palodent Plus/Triodent V3 System.

Slide the “Clear Metal” matrix into the embrasure, wedge and place the ring.  Apply bond and air dry, but do not cure. Then apply flowable, using an instrument to remove any air bubbles. Apply a tad more flowable then fully light cure from different directions.

open contact V3-Ring-Clear-Metal-Matrix-Instrument-to-remove-air-bubbles Light cure Fully light cure Fixed contact point

In most cases, deep cavity defects are cured in layers using standard procedures before the OVC3 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 OVC3 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 OVC3 and not the centre.

Spot-curing the core of the uncured composite stabilizes 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 stabilize the OVC3 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 OVC3.

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 OVC3 Replica and when checking the vertical position of the OVC3 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 OVC3 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.

Yes, in fact this is an easier procedure for beginners. We recommend completing 5-10 procedures using the semi-indirect method before moving on to the direct method. View our blog post “New semi-indirect OVC3 clinical technique video” for instructions.

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 subgingival area, sufficient to be able to apply the OVC3 directly. Use traditional build-up techniques to stabilise the prep as you would with a regular crown.

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 OVC3 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.