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What is BisCover indicated for?
BisCover LV is indicated for use on both temporary and definitive restorations. It can be used on direct and indirect composite restorations, as well as acrylic based appliances.
What are the disadvantages of the oxygen inhibited layer?
Liquid like or sticky
Low mechanical strength
Harmful or even toxic
How was BISCO able to make Biscover cure without the oxygen inhibited layer?
Generating lots of free radicals / time
Selecting oxygen resistant radicals
Increasing the rate of polymerization
Decreasing the rate of oxygen diffusion
Unlike Biscover, Traditional polishing is:
Lower gloss than BisCover
May damage adjacent tooth structure and produce surface imperfections on the restoration
Unlike Biscover, Temporary Glazes:
Have a unpleasant odor
Cannot be used inside the mouth
Unlike Biscover, Composite Sealers:
Cure with air-inhibited layer
Require additional step to bring to luster
Lower Gloss than BisCover
Will BisCover LV interfere with occlusion?
No. When placed in a thin coat BisCover LV is only 10-20 µm thick.
How does Biscover LV bond to any surface?
BisCover will bond due to surface adhesion (Van der Waals molecular attraction) and also will bond due to micromechanical interlocking because you etch the surface and the porosities present allow the penetration of BisCover leading to this retention mechanism. It is similar to an etched enamel bond.
Can you explain why Biscover LV has such a shiny surface?
The glossy surface is due to the smoothness of the surface, which is determined by the presence of the resin monomers and absence of particles. Monomers tend to spread and form a uniform layer on the surface. The smoother the surface is, the better the reflection of light and, therefore, it looks shinier.
Which wave length is effective for LED, Halogen, and PAC lights to polymerize BisCover LV??
BisCover LV absorbs light in the the range of 450 - 490nm, with the peak absorption at 470nm.
Wavelength output for Halogen curing lights is roughly in the range of 400 - 520nm.
Wavelength output for the typical blue LED curing light is roughly in the range of 460 - 480nm.
Wavelength output for PAC lights is roughly in the range of 380 - 520nm.
Therefore, BisCover LV is able to be cured by all of these types of curing units.
Why does the Biscover LV appear yellow in the mixing well?
The photoinitiator CQ is yellowish when not excited by light. When exposed to light, it changes the molecular structure and the yellowish appearance fades. The yellowish color is also related to the thickness (or volume) of the product layer. Once in a thin layer (as recommended application) the yellowish appearance practically disappears.
Why do the instructions recommend a 15 second dwell time?
There is a bleaching agent in BisCover LV to remove some of the yellow chemical color. If you evaporate the solvent for an extended amount of time, the product will cure very hard, but the bleaching agent cannot “move” and be effective within such a hard matrix to reduce the yellow color. If you follow the recommended evaporation time, you leave a little solvent behind and the product cures a little softer, but the bleaching agent is more effective and the yellow color can be lessened. Our current instructions recommend a 15s evaporation time. If the customer is having problems with the product curing with too much yellow color, they should first make sure they are applying the product in a thin layer, and then secondly they can try a 10s evaporation instead. Applying the material in a thin layer is even more crucial here, so as to not trap too much solvent and cause white spots. Regarding a maximum evaporation time, the customer should be able to let the solvent evaporate up to 30s and still get good results, but the key again is applying in a thin layer.
Do I have to shake the Biscover LV prior to use?
There is no need to shake the bottle, as BisCover LV is always homogeneous.
For use of BisCover LV prior to place orthodontic bracket, the instructions say to “Etch the entire area with phosphoric acid, such as UNI-ETCH w/ BAC, for 30 seconds (120 seconds for primary teeth).” Why do you need to etch primary teeth for 120 seconds compared to permanent teeth??
Enamel is made out of prisms. The enamel of primary teeth has a layer called "aprismatic layer." This layer does not have any prisms and is very non-permeable, thus reducing the effect of etching on primary teeth. It is a fact that you need more time to etch deciduous teeth's enamel. And the presence of an aprismatic layer is the reason.
Why am I not able to use Biscover LV on Glass Ionomer?
BisCover LV is indicated for use on top of a resin-modified glass ionomer, but it cannot be used on traditional glass ionomers. The reason is that LV cannot bond to traditional GI because its hydrophobic components are not compatible with GI's highly hydrophilic surface. However, LV can bond to RMGI via its chemical bonding to light cured polymers, overcoming the hydrophobic-hydrophilic incompatibility.
Why do you need to re-etch composites before placing the Biscover LV?
The reason for etching direct composites is 1) for cleaning purposes. It can remove any polishing debris better than rinsing with water; it can also remove saliva contamination. 2) In addition, when etching direct composites you are also etching the adjacent tooth structure (per our instructions), because you will want to apply BisCover LV there as well for a seamless polish and to seal the margins. So the etching step enables the BisCover LV to bond to the enamel.
Why is it not required to re-etch temporaries?
A provisional restoration is created outside the mouth, so cleanliness and saliva contamination are less of an issue, and in general you would be less likely to polish the adjacent tooth structure (or there may not be any) because you are only placing a temporary. Therefore we state that etching is not required. The fact that your provisional material and your composite might be very similar materials does not matter, because the etching step is not for the purposes of helping the BisCover LV to chemically bond to the material. Resin bonds to resin without etching. Rather, again the etching step is for the cleaning and to etch the tooth structure, as previously described.
Recommended tips for clinical success:
LESS IS MORE The best results are achieved when you start with the right amount of material on the brush. Avoid using excess material. It is easier and more effective to apply an extra layer if necessary than to remove excess. In addition, by applying the correct amount, the yellow color of the material will disappear during the curing process.
If you notice pooling in deeper areas such as pit and fissures on occlusal surfaces, it is important to remove the excess. A good method is to carefully blot with an absorbent tip of a microbrush. Do not agitate or disturb the surrounding surface where BisCover LV has already been applied.
BisCover LV can be used to enhance gloss following mechanical polishing. Do not use oily lubricants during mechanical polishing prior to applying BisCover LV on direct composite and indirect restorations.
Certify that your curing light unit is operating with adequate power density (light intensity) and that the probe is clean and undamaged. Low energy light output can compromise the final quality of BisCover LV.
Troubleshooting: The surface is not cured uniformly?
The light intensity may be less than the required amount. The lamp may be old and need replacement, or the internal filter may be scratched and dirty. SOLUTION: Use a radiometer to determine the actual output intensity, and/or increase the curing time.
The light guide may be too far away from the surface. Light divergence reduces the intensity at the curing surface as the light spreads to cover a larger area. SOLUTION: Keep probe 1-2mm from surface, and/or increase the curing time.
Residue build-up on the tip of the probe may block light and reduce the intensity. A chipped or scratched probe tip will also contribute to reduced intensity. SOLUTION: Clean the tip of the light probe, and/or increase the curing time.
Substrate was contaminated. SOLUTION: Apply a second coat of BisCover LV. Troubleshooting: Upon curing, my Biscover has white spots?
Insufficient evaporation of the solvent has occurred, usually due to application of too thick a layer or the entrapment of solvent within the resin. Remove the BISCOVER LV with rotary instruments and re-apply. Allow sufficient time for evaporation of the solvent before curing. Can a different applicator be used?
Yes. We find that a thin coat applied with a bristle brush provides the smoothest surface with Biscover LV. However, you may use any other applicator that is ethanol resistant. What is the shelf life of Biscover LV?
2 years Will Biscover LV interfere with occlusion?
No. When placed in a thin coat Biscover LV is only 10-20 µm thick. How long will the Biscover LV last?
The Biscover LV may last two years with toothbrush abrasion on direct composite restorations.
The intensity of the curing light may not be uniformly distributed as an output, falling off in intensity towards the outer periphery. This is further exaggerated as the distance between the probe and surface are increased. SOLUTION: When curing a large surface area, it is better to cure smaller sections at close range as opposed to the whole area from a distance. Troubleshooting: The surface is tacky after curing?