Cracked Teeth – Why?

June 2, 2015

One of the common problems we see as dentists is cracked teeth.  Any tooth can fracture, just like driving a truck over pavement enough times can crack the pavement, but the most commo reason is from the weaknesses caused by drilling and filling teeth.  Large amalgam fillings are like a lump of soft lead in a crystal glass, slowly creeping and expanding over the years until the tooth cracks apart.




While most cracks are horizontal and a cusp cracks of the tooth, a large number are vertical cracks extending into the nerve of the tooth and splitting the root in half.

Cracked tooth Cracked tooth 2 Root Treatment fracture-web-2 fracture-web-1

It is best to replace any metal fillings if any sign of cracking is evident, but replacement with tooth coloured fillings may not be strong enough.


The tooth should be supported with a full coverage of porcelain, or the best alternative which is gold.  The porcelain has a higher strength than plastic fillings but can still crack.  The gold will wear at the same rate as your own teeth and will not break but there is a cosmetic compromise.

4Porc Onlay Fracture 3 4Porc Onlay Fracture 5 4Porc Onlay Fracture 7 tamc2 DSC_0125

Talk to your dentist about which option is most suitable for you.


Cracked Tooth Syndrome fixed with eMax Crown

July 22, 2013

This patient started getting sharp pain every time they bit on this tooth.  It had never been filled but it started to split  This can happen from grinding (bruxing) at night, clenching, eating hard foods, or often old fillings have weakenbed the tooth.  In this case the patient admitted a very stressful period over the previous 6 months and an awareness of heavy clenching.

4Porc Onlay Fracture 2

You can see natural grooves and small enamel cracks in both teeth.  The pain was localised to the second premolar by biting on a hard object.

4Porc Onlay Fracture 3After removing the enamel a verticle crack can be seen extending into the tooth.  Without support this will continue down through the nerve and root of the tooth and the tooth will need to be removed.  Below is an image of a tooth where this has already occured.

1Fracturetooth1A porcelain shell like a helmet is made that can fit over the tooth and protect it.  We use only Australian laboratories and don’t source crowns from overseas.

4Porc Onlay Fracture 5Thanks to Jade Dental Laboratory in Buderim ,Queensland, for this artistic creation.

4Porc Onlay Fracture 7The crown is glued onto the remaining tooth to seal the crack and reinforce the tooth.

4Porc Onlay Fracture 6I have used eMax for this crown.  As it is cosmetic and translucent, I don’t have to agressively remove tooth structure all the way to the gumline like a traditional crown.  This leaves the tooth much stronger in the long term.

4Porc Onlay Fracture 4You can see where the tooth was reduced on the side.  Traditional crowns would mean removal of tooth all the way to the gumline.

Composite Bonding Rehabilitation

October 30, 2011

This lady had worn and chipped her upper teeth on the inside until they were so thin they were about to break. The yellow tooth on the right second from the middle is an old crown which the patient couldn’t afford to redo so we had to match it in colour and shape. Crowns are hard and durable but bonding often means less tooth needs to be removed and they are cheaper. Because all of this patients teeth had worn we were needed to build them all up (or at least 10 of them) – compare $250-$300 per tooth for bonding vs. $1500 per tooth for crowns. They may not last as long or be quite as perfect in appearance but they can be a great low cost option without losing teeth and getting dentures. It was done in one day and crowns would take weeks or even months.  I would be happy to get 5 years up to 10 years for this kind of procedure.  Despite the cost, in the long term I would still prefer porcelain crowns.

Adult with baby teeth – bonding

November 10, 2010

This dental patient was missing her lateral incisors and the adult canines erupted into the space, with the baby teeth canines still in place.  You can see the baby teeth have worn down severely, and the adult eye teeth look bulky in this position.

The best way to treat this would be by extracting the baby teeth, moving the eye teeth to where they should be with orthodontics, and then placing implants in the spaces.  Unfortunatley this would be expensive and take many months to complete.

While our patient is saving for the best long term solution, we were able to provide a great compromise using dental composite resin.  This will prevent further wear and is completely reversable.  It was done in one appointment for the cost of less than 1 crown.

You can see the compromise is the position of the gum due to the adult eye tooth being so large.  That is why orthodontics and implants in the long term will be the best option for the missing insicor teeth.

More tooth coloured fillings

November 30, 2008

Just haven’t had the time to write lately.  Here is a nice set of filling replacements I did this week.  The old amalgam fillings have cracked and leaked.  You can see the decay on the right side of the top filling, the crack in the middle filling, and the downside of large metal fillings is the cracked off cusp in the molar on the bottom. 


The molar needs to be crowned to keep the tooth for any length of time.  If it isn’t crowned the large tooth coloured filling may crack or leak and end up leaving the tooth in an unsavable state.  At this stage it has bought the patient some time to organise for a crown, and allowed me to see what damage lay beneath that old amagam and check that the nerve in the tooth will be ok.  The top 2 fillings went very well and should be there for many years if kept clean.

Happy Christmas all.