Crowns and Onlays
Affordable Crowns and Bridges in Auckland
In dentistry, ‘crown’ is a term that is used to describe both the natural part of the tooth that is visible above the gum level and an artificial cap that is used to rebuild and strengthen a weakened tooth.
A crown surrounds the whole tooth structure and is cemented permanently, compared to an onlay which may cover approximately fifty to seventy-five percent of a tooth and is also cemented permanently. Teeth need to be ‘crowned’ or protected by an onlay if there is a large filling on the tooth, if there is evidence of cracks within the tooth structure or part of the tooth is cracked or if the tooth has had a previous root canal treatment, all of which can significantly reduce tooth strength.
Crowns can be mainly divided into 3 different types. Historically gold used to be a very popular material due to its malleable properties, biological compatibility and resistance to corrosion. It behaves much like enamel in the mouth hence a well done gold crown can last for many decades.
The main disadvantage of gold is aesthetics. It is still used today mostly for restoring posterior teeth, especially for patients who have heavy bites and/or have parafunctional habits such as grinding. Gold is more forgiving on the opposing teeth for someone who grinds their teeth compared to porcelain and is less likely to fracture under high loads. Onlays can also be made of gold and provides beautiful restorations in the mouth.
The main disadvantage of gold is the aesthetics. It is still used today mostly for restoring posterior teeth, especially for patients who have heavy bites and/or have parafunctional habits such as grinding. Gold is more forgiving on the opposing teeth for someone who grinds their teeth compared to porcelain and is less likely to fracture under high loads. Onlays can also be made of gold and provides beautiful restorations in the mouth.
Along came the PFM (porcelain fused to metal) crowns. These crowns have a metal coping or ‘shell’ underneath and are completely covered with tooth coloured porcelain on the outside. The combination of these two materials made this type of crown very popular. There is the strength of the metal which can be either a non-previous alloy such as nickel titanium, zinc etc or precious alloy such as a mix of gold and copper and there is the aesthetic advantage of the porcelain.
One complication which can occur is the porcelain fracturing off the metal base. Depending on extent of fracture and location, sometimes it can be repaired with other tooth coloured materials, if it cannot be repaired then replacing the crown is the best option. The most popular crown/onlay material today is the metal free all ceramic option. Porcelain or ceramic is a type of glass and in the dental industry, this is improving vastly every day. Millions of dollars are spent in research by large companies such as Ivoclar Vivadent, Kerr, Shofu etc. All are working towards innovating a material which not only mimics the true aesthetics of a natural tooth when it comes to colour, translucency and opacity but also can withstand the forces of the oral environment and is very resistant to fracture and leakage. In Dominion Dental Centre our most popular crown and onlay material is IPS e.max. This ceramic currently gives the best aesthetic outcome when mimicking nature as well as providing very high fracture toughness.
Almost all of our restorations on anterior teeth are exclusively IPS e.max crowns and most posteriors also depending on the individual needs of the patient.
At Dominion Dental Centre we have Dental Crowns metal free option for posterior teeth where maximum strength is required, we opt for Zirconia. Zirconia is yet another type of ceramic with the strength properties comparable to metal. This is an excellent option for patients who prefer to be metal free but have very heavy bites where traditional porcelain may fail. Zirconia is also used in long span bridges where strength is pivotal.
Our dentists Dr Sumaya Ershad very experienced in placing crowns/onlays/bridge work. They have been looking after patients from multiple suburbs such as Mt Roskill, Hillsborough, Mt Albert and Sandringham for years.
After assessing each patient clinically, radiographically and having a thorough discussion with the patient in regard to material choices and aesthetic expectations a decision is reached as to which material should be chosen. The dentist also discusses why a crown vs onlay may be suitable for that particular tooth.
At Dominion Dental Centre, all our dental crown / onlay / bridge lab work is made by local labs situated in Auckland. Quality control is of tremendous importance to us. By using local labs and trusted Dental Technicians, we are able to ensure only authentic branded materials are used. Our pricing is very competitive when it comes to the standard of services we provide. A ‘cheaper’ crown down the road does not necessarily mean you’re comparing apples with apples. Outsourcing a crown overseas is much cheaper rather than having a New Zealand made crown where quality control is very strict.
If you would like to discuss any of the topics raised in this article or would like to discuss any other concerns regarding your teeth please do not hesitate to give us a call on 0800 PHDENTIST (743368), or text us on 027 527 0494 or email, contact us or send us Appointment Request through our website . Dominion Dental Centre is the trusted family dental care clinic situated in the heart of Mt Roskill and has been looking after adults, adolescents and children for many years.