Michael Miller, DDS
Iam getting tiny bubbles in the wash material of my impressions with Splash. Discus said to change the way we store them and bleed new cartridges, but my partner and I are still seeing bubbles. Have you heard of similar problems? I use epinephrine-impregnated cord soaked in styptin.
I also recently received studies regarding Crest Whitestrips. Crest says they work as well as dentist-dispensed bleaching, and they plan to take the product OTC. Do you have any unbiased studies or information regarding this product?
A: Bubbles in a vinyl impression usually are caused by a contaminant, assuming the material itself is not inherently porous. You can check this by extruding the material onto a pad into a thick enough layer that the set material will be able to be sectioned. Once it is set on the pad, cut it in half with a sharp #15 scalpel blade. There should be no voids. If there are voids, you should make sure you are using the correct mixing tip. If you are, then return the material to the manufacturer.
If the material has no voids, then you can be fairly certain that some contamination has occurred. This could be your latex gloves and/or the hemostatic agent. We suggest swabbing the teeth fairly aggressively with a cotton pellet saturated with hydrogen peroxide and then rinsing well. Do this before you remove the cord. This usually takes care of the problem.
We have requested evaluation samples of Crest Whitestrips. A preliminary review of the literature and anecdotal reports suggest they will definitely put a dent in dentist-dispensed home bleaching, since Procter & Gamble is already selling it on its Web site and it has been spotted in quite a few retail locations. There is a groundswell of resentment against P&G by many in the profession, and it remains to be seen where this product is going.
The strips themselves are reasonably comfortable, do not affect speech, and offer the ultimate in convenience since they are totally disposable. However, it is also certain that patients will still get the best and fastest results by using a tray. In addition, Whitestrips only cover (in most cases) canine to canine. So, to bleach all the visible teeth in most patients (10-12 teeth), they will need to use two strips at the same time, doubling their costs. Also, the package tells you to use the strips within four weeks of purchase, suggesting there may be a stability problem.
Q: I am currently using Nexus by Kerr with OptiBond Solo Plus. I am thinking of switching to Calibra by Dentsply/Caulk. Do you have any recommendations regarding the switch and the compatibility of Calibra and OptiBond Solo Plus?
A: The light-cured base component of Calibra will work fine with OptiBond Solo Plus, but we advise against using OptiBond Solo Plus with any dual-cure resin cement unless your restoration is less than 2 mm thick. In this situation, your light should be able to cure the cement. For thicker restorations through which the light may not penetrate, you would be much safer using a dual-cure adhesive such as Prime & Bond NT Dual Cure.
Q: Can you name a very opaque composite that blends invisibly when restoring an endodontic access? Is there a good opaquer to use first? My restorations always look very gray. I tried a cast porcelain inlay and that was a waste of time.
A: We have two cases in the 2000 annual edition of REALITY, starting on page 3-265. In the first case (photos 18-22), we restored the access opening to the level of the metal coping with a glass ionomer to simulate the opaque over the coping. This was a repair of a ceramometal crown. In the second case (photos 23-33), the all-ceramic crown being repaired did not require an opaque material, since the preparation itself was not opaque. For an opaque glass ionomer, you can use Fuji IX, which is also very fast-setting. You can also use Opaker from Kerr, which is listed on page 1-602 in the 2000 REALITY book, to opaque a composite core. In addition, your porcelain inlay should be at least 1.5 mm thick.