Composite build up protocols for complex class IV cavities with two shades – Tips & Tricks
Class IV cavity composite build up after trauma is a common reality, especially when it comes to children in mixed dentition phase. The treatment of choice is one of the following depending on the clinical situation, irrespective of the tooth/teeth needing endodontic intervention is a reattachment of the fractured segment in cases where it can be retrieved or build up with direct composite resin.
In a few cases, however, even after reattachment, discoloration of the fractured segment(s) occurs, and, as a growing teenager, it could be termed as an aesthetic failure and a nightmare for the individual.
Management of one such case is being explained here and the ideology behind this case is to preserve as much of tooth tissue as one can, yet achieve optimal esthetics with simple techniques following some basic guidelines.
A 15 year old female patient reported with a discoloured central incisor that had fractured 2 years before, and the fragments were reattached. Over a period of time, these became more opaque and rather obvious. The patient wanted to look better as she said she was embarrassed to smile.
On examination it was found out that the segments were very well sealed and it was the colour that was the main aesthetic problem.
The shade to be placed was selected and a rubber dam applied thereafter. It was realized that there was an enhanced zone of low value (or higher translucency) in the body of tooth number 11 when compared to 21. Looking at the age of the patient the idea was to blend the remaining tooth structure of that tooth but deriving clues of the incisal anatomy from the contralateral tooth No. 21 in this case.
The composite on the surface of the tooth and the tooth tissue that was highly opaque was reduced to leave behind a thin layer of translucent natural enamel. A wide wavy bevel was created at the interface of the tooth and the tooth was etched thereafter.
Bonding agent (Single Bond, Espe) was used according to the manufacturers instruction.
A single mass of Dentine (Filtek Z350, 3M Espe), Shade A3 was added to the box that had been created when the tooth tissues were cleaned and removed.
The Misura Instrument (LM Arte by StyleItaliano) was used to get the right amount of dentine mass in the box. An excess of Dentine mass usually leads to a more opaque restoration and if there is an excess of Enamel, it usually makes the restoration look greyish.
The primary anatomy of the tooth is created using a Fissura instrument (LM Arte by StyleItaliano)
A brush is used to slowly drag some material on to the enamel at the area of the bevel to make the demarcation line not visible.
As seen in tooth No. 21, there is pronounced halo effect in that tooth (21)
TIP no. 1
To create a nice halo, cut back the dentine in line with the anatomy of the natural dentition and, at the incisal edge, add some white opacious dentine. In this case Extra White or XW Body shade (Filtek Z350, 3M Espe) was used.
The tooth should be layered in accordance with the final surface contour of the tooth from inside out.
One layer of enamel is added as a big mass.
A2 Enamel (Filtek Z350, 3M Espe) was used in this case and the Condensa instrument (LM Arte by StyleItaliano) combined with brushes was used to create a primary surface macro anatomy and the form of the tooth. This mass of composite was then polymerized.
TIP no. 2
A water soluble gel was applied on to the tooth and the composite was polymerized for 60 seconds. This ensures much better conversion of the surface layer of the resin which is otherwise not polymerized enough as a result of the Oxygen inhibited layer.
The initial form of the restoration was achieved only as a result of addition.
It is then time to start with the finishing and polishing protocol.
Mark mesial and distal line angles. It is also suggested to mark cervical bulge area and areas of macro texture.
Polishing Discs (Soflex, 3M Espe) are used only mesial to the mesial line angle and distal to the distal line angle. They can be used gently cervical/apical to the cervical bulge area.
TIP no. 3
Do not use any form of polishing discs in the middle part of the restoration as it will reduce the texture (effect of the perikymata)
A red tapered fissure bur can be used to create micro anatomy when used horizontally and macro anatomy when used vertically.
In the body of the restoration the restoration is polished in a sequence using the rubber polishers, Astrapol (Ivoclar Vivadent)
After the initial polishing process it is imperative to give the restoration and tooth some time to rehydrate.
TIP no. 4
Always take some photos to re-evaluate the shade, shape and texture of the restoration at this point in time so that corrections can be made at the final polishing stage if needed.
As can be seen here the texture seems a bit too much and there is need for the restoration to blend better in the cervical 1/3rd part of the tooth.
Initial post-operative view shows heavier texture then desired in the restoration.
After 48 hours on the second visit the texture is softened a bit and, as a result of hydration, the restoration blends into the tooth well. The final polishing is then carried out using a Jiffy Goat Brush (Ultradent) with a 1um Diamond Polishing paste (Ultradent)
TIP no. 5
The final tool used to get a glazed finish is cotton polishing buff used on a straight hand piece as in this case at slow speed with very gentle pressure and no water. This enhances the polish in the area of grooves where ever micro texture has been created.
The final restoration blends in with the tooth structure and the adjacent natural dentition.
Final right lateral view.
Final left lateral view.
Final restoration: close up.
It is hereby concluded that
- Preserve the tooth tissue that you can
- Layering with 2 shades even in cases with complex anatomy works as long as the body thickness of the restorations are well controlled.
- The goal should be to add right, rather then cut back a lot later.
- Create micro- and macro-texture to harmonize with the rest of the dentition.
- Always give time for the tooth and the restoration to rehydrate. Evaluate the restoration after 48 hours before the final finishing and polishing.