DenDental whitening is a conservative treatment that offers important results in the harmonization of the patients’ smiles regardless of the technique used. Although this subject has already been extensively studied over the past two decades or more, there are always points that still cause questions and curiosity. The correct recommendation and the right timing to perform the whitening process while the patient is being submitted to a restoration treatment, are some of these questions.
For this reason, FGM prepared some questions answered by specialists in the area bringing information in a straightforward way to help the readers in their day-to-day in-office procedures.
Do patients that will have prosthetic work done on anterior teeth demand whiter teeth? Do they ask about whitening procedures? By Dr. Carlos Francci.
Nowadays, in general, all the patients that require prosthetic work for the anterior teeth also seek for whiter teeth. This way it is very common to be inquired about whitening. We have to point out that there are different clinical situations. In a more simple and common situation, when classes III, IV and V restorations will be replaced on anterior teeth, it is essential to whiten teeth previously to the replacement of the restorations. It is important to point out that the restoration replacement can only be done at least one week after the last whitening application due to the reduced adhesion and to the shade stability that must be achieved. Another situation is when a partial prosthetic work is performed only in some anterior teeth. In this situation, it is mandatory to do previous whitening, to define the shade that will be used on the prosthetic pieces. One last situation is specific for prosthetic work with no-prep veneers, where the substrate shade influences the aesthetic result. We always recommend the whitening to be done before in order to obtain the whiter shade with a more translucent ceramic, with more natural chromatic effects.
How often do you perform whitening procedures before the prosthetic rehabilitation (crowns, veneers and implants)? By José Carlos Garófalo
Every time I am requested a prosthetic rehabilitation work, direct or indirect, and mainly those that do not involve all the teeth structure, it is my protocol to ask the patient if he/she intends to have a previous whitening treatment. I ask that and explain that if the previous treatment is not performed, it will be very difficult to perform it later without running the risk of the restorations color become different from the natural whitened teeth. This way, as a clinic protocol, all the indirect prosthetic rehabilitation works using crowns, veneers and implants tend to start with a dental whitening procedure.
Is there any case when the whitening procedure is not recommended before the rehabilitation? By Alessandra Reis Bastos de Oliveira
There are rehabilitation cases where some teeth have structure loss with little remainders of the crown and many restorations with indication of a treatment with the use of porcelain crowns. Whitening procedures in these cases are not feasible and unnecessary. I would not recommend whitening procedures in cases with teeth with old and severe chromatic alterations where the color change would not be effective with the whitening procedure and in which a restorative ceramic material that blocks the dark color of the dental substrate would be used.
In what step of the restorative treatment (direct and indirect) do you recommend whitening? By Paulo Sérgio Quagliatto
One of the worst problems when we intend to restore teeth directly or indirectly, after dental whitening, is the considerable technical difficulty, because the teeth become dehydrated and without the adequate chromatic stability. Another negative factor is the presence of residual oxygen for a period of 7 to 14 days1,2, which makes it difficult for adhesive techniques and consequently the failures in the restorations.
Although studies have reported the use of sodium ascorbate as antioxidante3 agent for the completion of restorations in less time than 14 days, it was still observed color instability of the remanescente4. The ideal, therefore, is that if we restore directly with composite resins, adhesion on enamel only, that we wait for 07 days, and if the adhesion is on enamel/dentin, that we wait 14 days after concluding the whitening technique. For indirect techniques, the whitening must be carried out beforehand, and the adhesive cementation should be done 14 days after the procedure is finished.
We know that whitening may interfere negatively in the adhesive cementation when
done at the same time (ex.: cementation of the prosthesis during whitening). How
long after whitening do you cement parts? By Fabiano Marson
The oxygen released by the whitening action promotes the decrease of the adhesive resistance of direct or indirect restorations to the dental structure, therefore, it is necessary to wait 2 weeks after the end of the whitening to carry out the restoration1. In order to reduce the waiting time from the end of the whitening to the restoration, many authors have recommended the use of different antioxidants, such as sodium ascorbate which has a great reducing potential2-5. However, we should wait a minimum of 14 days to take the shade. Clinical example: we are making ceramic veneers on anterior central teeth and I will take the shade of the adjacent teeth (lateral). If I do that right after the whitening, I would be having as reference a shade with a higher value because the color of the teeth has not stabilized. That way, veneers will be made in a standard that is lighter than the lateral teeth impeding cementation.
It will be necessary to send those to the lab for the adjustment of the color.
References / Referencias
1 Dishman Mv, Covey Da, Baughan Lw. The Effects Of Per- Oxide Bleaching On Composite To Enamel Bond Strength. Dent Mater 1994; 10: 33–36.
2 Briso Al, Rahal V, Sundfeld Rh, Dos Santos Ph, Alexandre Rs.Effect Of Sodium Ascorbate On Dentin Bonding After Two Bleaching Techniques.Oper Dent. 2014 Mar-Apr;39(2):195-203.
Doi: 10.2341/12-054-L. Epub 2013 Jul 12.
3 Marson, F.C Et Al. Influencia Do Gel De Ascorbato De Sodio Na Resistencia Adesiva Entre Resina Composta E Esmalte Clareado, Revista De Odontologia Da Unesp. 2007; 36(1): 17-21.
4 Briso Al, Toseto Rm, Rahal V, Dos Santos Ph, Ambrosano Gm. Effect Of Sodium Ascorbate On Tag Formation In Bleached Enamel.J Adhes Dent. 2012 Feb;14(1):19-23.
5 Berger Sb, De Souza Carreira Rp, Guiraldo Rd, Lopes Mb, Pavan S, Giannini M, Bedran-Russo Ak. Can Green Tea Be Used To Reverse Compromised Bond Strength After Bleaching?. Eur J
Oral Sci 2013; 121: 377–381. 2013 Eur J Oral Sci