Dental procedures explained… (Not quite sure what your dentist meant? Here it is explained in “layman’s terms”)
So you went to the dentist with tooth-ache, expecting to leave with a dental filling, however the dentist informs you that you require a dental crown…
What is a dental crown?
You may have heard it referred to as a tooth crown, dental cap, dentistry crown or just crowns. And often, the public confuse dental crowns with veneers. .. but they are very different…
When you have a cavity, the dentist will drill away the decayed parts of your tooth and fill it with dental filling materials in the form of a filling or inlay/overlay. They could be white fillings known as composite fillings – these are currently one of the most popular materials to used, alternatively the dentist could choose Gold, Zirconium, composite or porcelain to fill the gap. Back in the day amalgam dental fillings where very popular but its popularity has started to diminish due to the lack of esthetics , the availability of newer, better, more technically advanced materials, but mostly, due to concerns about the toxicity of the mercury that is used in this material…
However, if the tooth is so badly damaged by decay that it can’t support composite fillings or an inlay, a dental crown is the next best option – its is a tooth-shaped “cap” that gets bonded over your damaged tooth to restore its natural shape and improve its appearance, to protect the tooth and to restore its size and shape… in order to do this the dentist will drill all the decay away leaving a small part of your tooth (like a little stump) to bond the dental crown on to – this process is called prepping teeth -the tooth is called a prepped tooth…
Your dentist may recommend a crown to:
- Replace a large filling when there isn’t enough tooth remaining
- Attach a dental bridge
- Protect a weak tooth from fracturing
- Cover a dental implant
- Cover a tooth that has had root canal treatment
- Cover a poorly shaped or discoloured tooth
- Restore a fractured tooth
- Smile makeovers
Dental crowns can be made out of a selection of different materials. Between your dentist and the Dental Laboratory, the correct material for your crown will be decided . Some of the different types of dental crowns being: e.max Crowns, Zirconia Crowns, Gold Dental Crown, Porcelain Crowns , BruxZir Crowns , Porcelain fused to metal crowns/VMK.
Here at Newvision Dental Laboratory we prefer to use IPS e.max Press – it is a lithium disilicate glass-ceramic – with a strength of 400 MPA. We feel that one can get the most natural restoration possible due to the translucency and highly esthetic nature of the material. Simply put – our dental technicians can create and stain your capped tooth to make it look as real as your natural tooth – (because quality is our pride – for examples of smile make overs – visit facebook.com/newvisiondental.laboratory)
Unfortunately e.max material cant be used in all cases , and in these cases, we at Newvision Dental Laboratory will create a VMK otherwise known as PFM (porcelain fused to metal) crowns or BruxZir Zirconia crowns.
When Dental Labs do bridge work/a dental bridge for example, e.max generally cant be used. Should you require a dental bridge (eg 3-unit bridge, 4 unit, 5 unit etc) depending on the size of the pontic and where the dental bridge is situated in your mouth and the masticatory force, e.max may not be a suitable dental material – the dental technician may then opt for a VMK Crown or BruxZir Zirconia Crown . The specifics of this in regards to using e.max as your dental material to create your dental bridge – in the anterior region up to the canine, the pontic width may not exceed 11mm and in the premolar region, the pontic width may not exceed 9mm – the pontic width being determined by the width of the missing tooth before it is prepped.
In lay-mans terms… if you have a tooth that is completely missing – roots an all – the best solution is to have an implant supported crown created for you (we’ll cross this bridge later to explain in full – pun intended!) However, for some people, implants can be out the budget and therefore a more affordable solution needs to be found… alternatively, you may have left this gap for too long causing the bone to absorb and if there is no bone, implants won’t work – you could have a bone graft, yet this may also be out of the budget… and then there is the risk that the dental implant may be rejected by your body… What ever the case may be – you may find that the best solution for you at that time might be a dental bridge – so basically for example – a 3-unit dental bridge – if you are missing a tooth near the back of your mouth – due to the masticatory force (chewing force) being stronger, if the gap is larger then 9mm, e.max should not be used and similarly in the front of your mouth, if the gap exceeds 11mm e.max should not be used.
At Newvision Dental we prefer to make our dental bridges either in BruxZir Zirconia or as a VMK/PFM – porcelain fused to metal.
What is BruxZir Zirconia?
“BruxZir® Solid Zirconia is a monolithic zirconia crown, bridge, screw-retained implant crown, inlay or onlay with no porcelain overlay. First launched as being “More Brawn Than Beauty,” the material was originally intended to provide a durable, more esthetic alternative to posterior metal occlusal PFMs or cast gold restorations for demanding situations like bruxers, implant restorations and areas with limited occlusal space. Now, thanks to the new BruxZir Shaded formulation, BruxZir restorations exhibit improved translucency and colour similar to natural dentition, making them a restorative option in the anterior as well. Complete colour penetration all the way through the restorations ensures greater shade consistency and prevents any shade changes after occlusal adjustment.”
Initially BruxZir Zirconia was very popular as a solution for patients that grind their teeth (Bruxers) who have destroyed other restorations, as it is very durable, and even though it is not as esthetic as e.max it looked better in the mouth then a gold dental crown or VMK crowns. Also recommended for implant crowns and cases where there are occlusal space limitations. Now they have come up with a new formulation that improves the translucency of the crowns or dental bridge so that they can look more natural in the mouth – more like real teeth… conclusion the material is both functional and esthetically pleasing and is available to dentists and Dental Labs for those complex cases or as an alternative to PFM. Here at Newvision Dental laboratory we veneer BruxZir Zirconia crowns with porcelain to further improve esthetics and to make it easier for dentists to grind the bite in.
Even though BruxZir Zirconia seems like the obvious choice over VMK/PMF for making a dental bridges, dentists still request VMK bridges. Why is this? The main reason is that a dental bridge or dental crowns made as a VMK or PFM as apposed to it being made with Bruzir Zirconia is the dental cost, VMK crowns are currently the cheaper option. To add to this, there seems to be a fear or misconception that BruxZir Zirconia crowns may de-bond quicker due to its acid-resistant nature.
To elaborate a bit – when you bond a dental crown or dental bridge on to a tooth – both the tooth and the dental crown or bridge needs to be primed with specific adhesives – crowns at our dental laboratory are acid etched with Hydrochloric acid.
However BruxZir Zirconia Crowns are made to resist and withstand pretty much anything – so naturally being acid resistant means that you can not acid etch them… subsequently they do have their own primers that can be used. BruxZir Zirconia crowns are also still very new to the market in comparison to VMK/PFM and I guess you could call this a case of familiarity breeds contentment.
In the past, if you went to your dentist for a check up – maybe you have sore sensitive teeth – and the dentist suggested you required a crown, however it is a possibility that you may need to have root canal done, for example, the dentist would then bond your crown with temporary cement, and monitor your progress, and should you then need root canal treatment, the dentist can remove your crown a bit easier then if the crown was bonded with permanent cement… We at the Dental Laboratory have noticed the trend – that if the dentist is going to be placing a crown with temporary cement, they generally ask for VMK…perhaps as BruxZir Zirconia Crowns become more popular and dentists more aware of the esthetic benefits of this material, for those challenging cases, the trend will start change… or maybe a newer, exciting product appears on the market – only time will tell…
So, you have an idea about what e.max material is and about BruxZir Zirconia Crowns… now you may still ask what is a VMK or PFM Crown and “what are teeth bridges” /what is a dental bridge?
VMK crowns , also known as Porcelain fused to metal crowns (PFM) were first created by Vident, a subsidiary of Vita, in 1962 and was the first ever metal ceramic. Due to an ever growing demand for a metal ceramic that was both functional and esthetic, Vita took up the challenge and developed a material that met these criteria – it was called “Vita Metal Keramik” which is where the abbreviation “VMK” comes from. To describe simply what a VMK crown is – lets refer to its other name – PFM – as the name describes – it is porcelain fused to metal… If this is still a little bit out of your grasp, this basic description on how it is made (in lay-mans terms of course) may help…
Right, so first we need to make the metal coping – this is the base of the VMK crown and is the metal “casing” that fits snug over your prepped tooth. The way we know it will fit “snug” over your tooth is because when you go to the dentist and the dentist preps your tooth, he then takes an impression of your teeth and sends it to the Dental Laboratory – we then create a plaster model of your mouth using that impression, and we use this to make sure the work is unique to you and fits exactly on to your prepped tooth.
Now to create the metal coping we use the “lost-wax technique” or “lost-wax casting” this method is also used by artists creating metal sculptures… First we create a “wax version” of the coping. Then we place it in refractory/investment material – for example, cement, ensuring that there is an access hole to the wax coping. The wax is melted out and metal poured or cast in, replacing the wax – the metal used will depend on what metal/alloy you want the coping to be made out of – VMK crowns can be made out of gold, palladium, (which is semi-precious) chromium base metal (which is non-precious) or nickel titanium alloys. (This is the metal we at Newvision Dental Laboratory normally use)
After the coping is created – the porcelain is then bonded or fused to the metal hence the name porcelain fused to metal.
Now you know what a PFM crown is, now lets explain the bridge: to recap what we said earlier, reasons you may be “prescribed” a dental bridge as a solution to your missing tooth/teeth:
- Budget – it is recommended to get an implant supported crown – how ever, they can be costly.
- Not enough bone available to have implants – or not enough budget to get a bone graft.
- Main reason – to replace missing teeth – to bridge the gap created by one or more missing teeth.
There are 3 main types of dental bridges:
Traditional Dental Bridge:
This is the most common type of dental bridge – where the teeth on either side of the gap are prepped and crowned (we call these abutment teeth) with a pontic between them. The ” dummy tooth” in the middle of the bridge (in the middle of the two crowned teeth/abutment teeth) is called a pontic. Depending how many teeth are missing will determine how many pontics there are – these “dummy teeth/pontics” are attached to the crowns on either side of it to create the dental bridge. (For a better understanding – see the pictures on our website)
Cantilever Dental Bridge:
This type of dental bridge is a little less common. Where a traditional dental bridge will have the pontic between two abutment teeth, as mentioned above, the Cantilever dental bridge only has one abutment tooth – so only the one tooth next to the gap will be prepped and crowned and the pontic attached to it.
Maryland Dental Bridge or bonded bridge:
This bridge is also called a resin-bonded bridge. This dental bridge can be made from plastic or composite – these would require ribbond strengtheners which are made out of glass fibre. Alternatively they can be made from metal or Zirconia. At our dental laboratory we have found the best results have come from making our Maryland bridges out of metal overlayed with porcelain – think Porcelain fused to metal crowns. This dental bridge has metal wings on each side and these are bonded onto the existing teeth. (The teeth adjacent to the gap)
Dental Bridges can:
- Restore your smile.
- Restore your ability to speak or chew properly.
- Maintain the shape of your face – to prevent your cheeks “sagging in”.
- Distributing the chewing forces in your bite correctly by replacing missing teeth.
- Smile makeovers.
- Prevent remaining teeth from drifting out of position.
- Prevent opposing teeth from over -erupting.
- As an alternative and permanent solution to dentures.
So what does a dental crown or dental bridge cost?
Dental crowns and Dental bridge prices vary from dentist to dentist and while it is perfectly normal to seek out an affordable dentist, cheap dentistry is not always your best option – rather look for dentists that are well known and come highly recommended, but more importantly, that work with a Dental Laboratory that is recognised for producing quality dental work as they will be making your crowns or bridge.
To find a dentist in your area that comes highly recommended – who work with a Dental Laboratory, where quality is their pride, and for examples and pictures – or if you would just like to read more about dental work/dental procedures or dentistry, click on the relevant tabs on our website (we work closely with Cape Town dentists in Sea point, Durbanville, Rondebosch, Tamboerskloof, Newlands and Cape Town CBD) but we can also work with your existing dentist too should you prefer.