. Education

#TubulesLive Event: Bio-emulated Indirect Posterior Restorations

A bit belated, but here is the summary of the #TubulesLive event that was held a few weeks ago with the charismatic and funny David Gerdolle.

So are bonded restorations safe? Bonded restorations require flat preparations but does this compromise the lifespan of this sort of restoration? Here I shall summarise the points from Dr Gerdolle's talk.

Bonded restorations (either ceramic or composite) can be BIOMIMETIC i.e. they can mimic the natural appearance of the tooth tissues
According to some studies, the 10-15 year survival rate of these restorations is similar to that of conventional full coverage restorations
The difference is not the lifespan, but what happens when the restoration fails.
Very few failures with bonded restorations are catastrophic failure compared with conventional prepared restorations as you are preserving more of the tooth tissue
You can produce a more aesthetic outcome, not only because the restoration is tooth-coloured, but you are also preserving more of the natural tooth
The key pillars of tooth preparation are:

Biological imperative - Immediate Dentine Sealing (IDS) with bonding +/- composite. This is the ideal as it seals the freshly cut dentine which increases the bond strength and protects the pulp during the temporisation stage. It also prevents bacterial leakage and contamination with the temporary cement. This also means that you will not require anaesthesia at the cementation appointment which will help you protect the pulp when curing the luting composite
Cementation imperative - consider the Configuration Factor (C Factor) when designing the cavity, MOD cavities are unfavourable as the shrinkage stress will product micro-cracks, therefore the best preparations are the 'flat'
Prosthetic material imperative - materials usually require 2-3mm of room so that they are thick enough for resistance but thin enough to allow you to polymerise through. You should use calibrated burs to help you achieve this as it is best to prepare the tooth under rubber dam

Deep margin elevation (DME) can be used in teeth with deep subgingival margins. The other options is to do crown lengthening, but this means that the papilla disappears
There is evidence to support that DME is an effective treatment option as long as you can properly isolate the margin with the rubber dam and matrix system
Some hands on tips include not removing all the cusps or old restorations when preparing these cavities as they will help you isolate the tooth properly and using a sandblaster to remove any corrosion products and remnants of the old restoration
If you need to elevate a box, the best material to use is restorative composite rather than flowbale as the flowable will shrink
Use preheated 'hot' composite to cement the restoration in the following steps:

Remove the temporary and sandblast the preparation with a matrix around the preparation to protect the adjacent teeth
Etch with phosphoric acid
Silaning agent application
Hydrophobic bonding stage
Apply the hot composite which makes the composite more viscous. Using a dark shade is best to prevent a translucent line at the margin

Dr Gerdolle's presentation was of fantastic quality and he was very engaging despite having spoken for the majority of the day. He really helped me to understand this biomimetic approach to restoring heavily restored teeth.

Do you use this sort of approach when providing patient's with indirect restorations? Or used hot composite before? Please leave your comments in the section below!

To see my posts about previous #TubulesLive events see here.