Opalescence, Opalescence F and Opalescenceall have a pH of 6.5.
2. If a syringe of Opalescence contains more, smaller bubbles than usual, does it mean the product has been activated before its application?
From flavor to flavor and depending on the filling process, Opalescence syringes can be found with no bubbles or with many small bubbles. Many of the pictures in our literature and catalog show the product with many small bubbles. These bubbles do not result from peroxide decomposition in the syringe; they are simply inherent in a thick formulation such as this.
3. Why does Opalescence change to a dark purple/black color when it comes in contact with amalgam?
The dark purple coloration that may appear in the tray following bleaching adjacent to older amalgams is normal and has proven inconsequential, based on years of clinical use. No adverse/detrimental effect on the amalgam restorations has been experienced. It has been theorized that the zinc in old amalgams may be the cause of the discoloration.
4. How does oxidating stains lighten them?
Whitening is a modification of the anatomy relative to the oxidation process, which eliminates the dark, disfiguring intra-dental organic dyes and stains by breaking down the conjugated double bonds of the color (selective light) absorbing offending molecules. Conjugated double bonds occur in many different molecular configured color-absorbing molecules. They are part of said molecule, which is ... C-C=C-C=C-C= ... etc. Bleaching oxidizes the internal tooth-disfiguring color molecules, changing them to alcohols, ketones and terminal carboxylic acids, etc., which eliminates the light-absorbing properties of the conjugated bonds. These are not cells or the constituents of cells; they are unwanted dye molecules within the noncellular matrix, namely dentin and enamel.
5. When bleaching teeth, why does the cervical portion of the tooth respond less to treatment than the incisal edge?
There are a few reasons for this occurrence. The simplest is that the enamel is thinner at the gingival third, so the dentin shows through more easily. The dentin can take longer to bleach than the enamel of the incisal third. The gingival third may not have caught up with the rest of the tooth yet.
6. How long should you wait to bond after a bleaching treatment?
Normally 7-10 days. However, there was a study at University of Texas (Barghi N, Morgan J. Reducing the Adverse Effect of Bleaching on Composite Enamel Bond. Journal of Esthetic Dentistry, 1994, Volume 6, Issue 4; 157-161) that indicated that when in a pinch, you could bond immediately after bleaching (using up to 35% carbamide peroxide) by applying an acetone-based, A & B mixed- type dentin bonding agent system prior to bonding.
7. What is the youngest age at which a child can bleach?
There is very little published on the whitening of primary dentition. Although the study only deals with adult dentition, clinical trials on nightguard vital bleaching techniques at the University of North Carolina have found no predictors of sensitivity relative to patient age, pulpal size, presence of exposed dentin or cementum and caries. Clinical experience has shown that even young people's teeth will bleach with no surprising side effects. We do recommend that in order to ensure an even level of whitening, all of the permanent dentition should have fully erupted. If the child bleaches before this has occurred, the teeth that erupt proceeding bleaching will be a darker shade than those that have previously been bleached. Another important consideration is whether the child would be capable of following the doctor's recommendations and instructions.
8. If a tooth has been restored with composite, does the restoration need to be removed before the whitening process? It seems that bleaching the unrestored surface would cause sensitivity since the peroxide goes into the dentin.
As per the Opalescence instructions, it is important to have all exposed dentin properly sealed due to possible sensitivity occurring during the whitening process. Hence, it would be recommended to leave the existing composite restoration intact during the whitening procedure. Another consideration for leaving the restoration intact is due to the fact that there is no way of predicting what shade a person's teeth will be after whitening. For this reason, it is better to replace restorations after the whitening procedure to ensure that the proper shade of composite is used. However, it is important to wait two weeks after whitening before a restoration is replaced in order to give time for the shade of the whitened teeth to stabilize. This will also allow the peroxide to diffuse out of the teeth, which will give better bonds.
9. Why does a non-vital tooth turn dark?
There are several reasons for a non-vital tooth to turn dark. One of the reasons is intra-coronal bleeding. Blood gets trapped in the dentinal tubules and the hemosiderin of the blood blackens.
10. If a patient that has previously suffered with carcinoma in situ on the floor of the mouth, would the use of 10% carbamide peroxide increase the risk of a recurrence? The patient has been clear of the problem for 3 years.
Studies, and as backed up by Yimming Li, show that the peroxide will not add to the carcinoma phenomena.