Dealing with multistained spots using minimally invasive techniques
Treatment of Enamel white spots with resin infiltration technique has been previously described (1–4).However, a lot of patients can present multistained dyschromia, i.e. both kind of white and stained defects (yellow, brown, dark brown). The aim of this article is to present systematic procedure to simplify, secure and make this kind of treatment predictable, understanding the underlying mechanism of such dyschromias.
On one side, in born or post eruption staining are linked to chromatic molecules within structure of the tooth hard tissues. The Aim of « Bleaching » treatment is to change conformation of these molecules, to avoid interaction with visible light. After treatment, Teeth show their natural original white appearance.
On the other side, Enamel white spots are not linked to “white stains”. Histologically, enamel white spots are related to porosities inside the enamel prism structure. These porosities lead to high light refraction. The hypomineralized enamel appears to be opaque, surrounded by the translucent sound enamel.
Using Resin infiltration technique, porosities leave space to TEGDMA solution, which present an index of refraction closer to the enamel. Hence, light reflection decrease dramatically. The hypomineralized enamel appears as translucent as the surround sound enamel. Which means it cannot be seen anymore clinically.
The approach followed for these cases is :
1) Proper hygiene, professional cleaning and aeropolishing with glycin, calcium carbonate or sodium bicarbonate powder, and mechanical polishing with prophylactic pastes.
2) At home bleaching, using 10% peroxyde carbamide with personnalized trays, during night, according to haywood technique(5). It shows best long term results and lowest rik of sensitivity (6). 3 weeks are effective in most cases. Sometimes, deeper or stronger stains need longer treatment. Protocol for tetracyclines stains has been described, with 6 to 12 months duration. Amalgam stains can’t be removed due to their metallic/ionic Protein bindings structures.
Clinically, bleaching are useful for 2 majors reasons :
It removes stains inside spots, and transform stained spots into white spot that can be easily treated by resin infiltration technique.
It decreases contrast between hypomineralized and sound enamel.
Sometimes, at this step, there is no need for further treatment like resin infiltration, due to sufficient patient satisfaction.
2 weeks of release after bleaching are mandatory before any bonding procedure. Adhesive protocols are disrupted by bleaching, indeed (7) . Remineralization treament can be performed during these 2 weeks, using ACP/CPP for example(8).
Then resin infiltration technique, superficial or deep, can be performed (cf. clinical case)
Img. 1 – Patient consult for aesthetic complaint related to white spots. Yellow areas haven’t been noticed by the patient.
Img. 2 – Cross polarized light picture shows opaque white spots and high saturated areas. Plaque and calculus are present on buccal and inter proximal spaces. Fluorosis is diagnosed. (TF index 2 to 3)
Cleaning and bleaching is considered as first option.
Img. 3 – Smile after cleaning and bleaching protocol (5 weeks: peroxyde carbamide for 3 weeks during night with personalized trays, and 2 weeks of CCP/ACP). Stains have been removed. White spots are even whiter, but bleaching decreased contrast between white spots and sound enamel. At this point, patient satisfaction is better, but still not enough.
Img. 5 – Before and After bleaching procedure. Please note that the 2 pictures have been taken with same settings. Gum can be taken as colorimetric reference. After bleaching, teeth appears lighter a lot. Bleaching increases white spots. It decreases naturally in few weeks
Here, patient decided to go for superficial resin infiltration right away, for the upper arch only.
Img. 6 – Operative field is mandatory to perform this procedure safely.
Img. 7 – Chlorhydric Acid 15% buffered (Icon etch) is applied and rubbed. Micro-brush applicators are used instead of Icon applicators to avoid waste and allow to reach narrow interproximal areas.
Img. 8 – Acid is removed with a cotton roll first to avoid splashes. Then, teeth are rinsed extensively.
Img. 9 – Teeth are dried showing chalk like aspect.
Img. 10 – Ethanol solution (Icon dry) is applied. It allows to dehydrate porosities in order to reach better resin infiltration. This step simulates post op result. Some areas can stay white during ethanol application, meaning porosities couldn’t be reached by the infiltrant.
Second row of etching step is indicated on these white refractory areas.
Img. 11 – Acid is applied second time on white refractory areas.
Img. 12 – Second ethanol application chows better infiltration. As seen, on picture, white refractory areas appear more translucent now. Some areas still appear white. There is a balance between aesthetic result and the amount of enamel to sacrifice. In this case, it has been decided to avoid third row of etching.
Img. 13 – After drying step, hypo mineralized enamel appears the whitest, since air is present within porosities.
Img. 14 – Resin infiltration is performed under light protection to avoid premature curing. Resin infiltration (Icon infiltrant) is rubbed of teeth surface during 3 minutes.
Img. 15 – Excess are blowed and removed from inter proximal space using dental floss.
Img. 16 – Resin infiltrant must be cured 40 seconds for each tooth. Curing from palatal side can be interesting: « Dark» areas (white arrows) show hypomineralized enamel that has not been infiltrated. These areas correspond to white refractory areas during the ethanol step. A second row of resin application and curing is needed.
Img. 17 – Excess must be removed using abrasive silicon point on red handpiece (Brownie, Shofu). Polishing avoid post operative staining of the non filled resin excess. Mechanical lustring is obtained with any composite polishing system (sof lex spiral system, 3M and then occlubrush, Kerr in this case). Natural roughness of the enamel surface has been respected and appears shiny.
Img. 19 – 1 year post op
Img. 23 – before and one year after treatment under cross polarized light
Understanding underlying mechanism of each kind of dyshromia allows us to offer minimally invasive, economic, safer and easier treatment. They are highly predictable and present low risk of per or post operative complications. In case of teeth colour complaint, they should be always considered as first option, before composite stratification or Veneers techniques.
Acknowledgements to my respected masters, Gil Tirlet and Jean Pierre Attal, who introduced me to minimally invasive approach.
« Happiness only real when shared » Chris McCandless / Alexander Supertramp