Dr. Elie Warde, Paris
Dear Otmar,
I have an ADEC dental unit. Is there any adapter to supply air from the dental unit to the VITA CEREC POWDER bottle (Case solved Dr. Rauscher in BlocTalk 1/09)?
Best Regards
Dr. Elie V. Warde
Reply of Dr. Andres Baltzer
Dear Dr. Warde,
The problem of matting of surfaces to be digitized using a scan camera has been discussed over and over again. It seems that every user has his own tips and tricks and the bottom line is that there is no perfect solution. Further research needs to be conducted to determine if scans are technically feasible without matting or contrasting. There are frequent reports about solutions which are to be introduced and marketed soon. However, to date, reliable results have not been presented.
During the FDI congress in Stockholm in 2008 PD Dr. Andreas Bindl, Zurich, gave an enlightening speech on this problem. It appears as if every user can be successful with the product of his choice. However, it is essential to keep options open that are more suitable for special situations.
1. Adhesive for powder dusting (VITA)
General recommendation:
Always recommended for matting with dry powder
2. Sprayer for dry powder with isobutane cylinder (VITA)
o The relatively large bottle may render handling quite difficult
o The pressure does not remain on a constant level when the gas content decreases
o The cylinder empties rapidly
o Icing and formation of lumps caused by the formation of condensed water can not be avoided
o Fading of undesired powder accumulation can be easily accomplished
3. Sprayer for dry powder (VITA) with coupling for compressed air gun (e.g. Sirona)
o Can be conveniently attached to compressed air gun
o Is offered by various manufacturers
o Icing and formation of lumps caused by the formation of condensed water can not be avoided
o "Spraying around the corner" is slightly difficult
o Fading of undesired powder accumulation can be easily accomplished
4. Sprayer for powder in a quickly evaporating solution – so-called scan sprays (Sirona, Dentaco, etc.)
o Spray nozzle may be clogged (better than it used to be)
o Fading of moisture accumulation in corners and recesses can no longer be accomplished after drying
o Expensive
o Subsequent spraying and optimization of the matt surface is quite problematic
o The ensuing removal with water spray is not unproblematic for certain spray products
5. Sprayer of dry powder using a special compressor (PowderChamp)
o Compared to cans or bottles - high return on investment despite the high initial purchase price
o It is ensured that the powder is kept dry
o Very fine and constant delivery, compressed air flow can be adjusted
o Subsequent spraying and fading are always possible
o No icing or formation of lumps
o Fading of undesired powder accumulation can be easily accomplished
Summary
Within the scope of the scanning processes, the following requirements should be fulfilled for optimized optical conditioning:
- Contrast powder is spread in a thin coat and a uniform layer thickness is obtained
- Fading of accumulated material
- Exposure of preparation borders using a probe and/or dental floss without scaling off adjacent spray layers
- Optimizing respraying and fading to maintain uniform spray layer (coat) thicknesses
- Complete and trouble-free removal of powder using water spray
The zone to be sprayed must be kept dry in all situations.
April 2009
Dr. Andres Baltzer, Gartenweg 12, CH-4310 Rheinfelden
Reply of Dr. Andreas Bindl:
Unfortunately, I don't know the ADEC unit in details. What I know is that it is dentist's chair operated by compressed air. Vita does not offer any adapter for the Vita powder bottles. Therefore, the dentist should contact ADEC directly to ask if there is such a piece - or craft one by himself.
Reply of Dr. Alessandro Devigus:
Sirona produces adapters for the insert of the CEREC Powder at the multifunctional syringe. Thus, they should know which units are supported.
Dr. Johannes Ott
I am interested in how the non-vital tooth is palatally prepared in your case (BlocTalk Issue 4/08). Is the canal partially prepared like an endo-crown or is the canal closed with a filling?
Response
Dear Colleague
Thank you for your interest.
I use three different versions of preparation, depending on the degree of damage and the apparent quality of the residual tooth substance.
In the current case, the residual tooth substance was fine and I did not continue to dissect palatally. Thus, I did not include the previous trepanning opening. It is now sealed with acrylic filling. Therefore, only the cutting edge (shown in the visual field of the photo) is included. This way the portal to the lumen of the crown is palatally accessible and eventual colour changes of the veneer – based on diffusing pigments from the tooth root to the dental crown – can easily be restored by internal bleaching of the tooth stump. The visual impression remains adjusted to the adjacent teeth.
In other cases with worse residual substance, I include the trepanning opening analogue to the CEREC endo-crown in my preparation to improve the stability, hoping that I do not have to re-bleach internally at a later time.
A third alternate version enables the primary setting of a ceramic spike in the root canal, with the length depending on the size of the root canal. After the adhesive fixture, I cut the excess length of the spike and prepare the tooth for the veneer, analogue to the present case.
Compared to the CEREC endo-peg, the zirconium peg is larger. Therefore, the tooth root receives maximum protection against breaking. On the contrary, an internal re-bleaching in this case is not possible.
This correction however will only be necessary in individual cases. And – as commonly known – in life, you cannot have everything at the same time.
I am looking forward to further discussions.
Best regards
Ekkehart Brueckmann
Dr. Albert Pietsch, Lämmerspiel, Germany
I must admit that I often regard company information sites rather critically. Mostly these show dry advertising content which is only presented differently. Unfortunately, well-designed and informative websites suffer under this experience. Here BlocTalk is an exception. The topics are suitable and the practical tips in the user reports are valuable. I will also send in a case report from my practice. Yours sincerely Albert Pietsch, Lammerspiel
Dr. Ekkehart Brückmann, Landshut, Germany
It would be worth discussing the various construction methods for the various cases in which veneers are applied. Beside everyone's own testing practical tips like the comment of Ms. Höfermann (BlocTalk 2/08) can save several hours in front of the Cerec screen including improved milling results.
Thomas Sekersky, Edmonton, Canada:
Hi… I think that Nandi Höfermann did a great article on veneers (BlocTalk 2/08). Are there any tips like that on “replication”? I’ve tried “waxing” and then tried to “replicate” it with not very good results. Can you help? Thanks Thomas
Editor's note:
If you as a BlocTalk reader have advice concerning "replication", contact us and your tips will be published online. We are looking forward to your feedback.
Reply by Nandi Höfermann:
For optimal replication design, draw the green copy-line in its outside dimension analogue to the preparation of the neighbouring tooth or replication tooth. Keep care not to be deeper in the interdental space with the green line as the height level of the neighbour preparation appears, because the size of the veneer you want to work with is fixed here (Figure 1 & 2). In the next steps of design you can follow the exact instructions I gave in the veneer article on VITA BlocTalk (Figure 3). Always remember: In replication it is only the veneer surface texture and not the veneer body. This must always be treated according to the steps of construction as in the tooth database mode.
Figure 1 Figure 2 Figure 3
Tips from Dr. Gerhard Werling, Bellheim, Germany, for polishing VITABLOCS using Soflex discs
The polishing by Soflex discs has a very good result as described in the case of Dr. Wolf and Dr. Bindl (BlocTalk 1/08). Here is my user information:
Unfortunately, especially rough discs often also remove the surface texture. This can be avoided by a simple modification of the Soflex discs. We cut them into „star design" and then obtain extraordinary polishing results while the surface texture is not affected.
Dr. Thomas Brunner, Frauenau, Germany: "A perfect platform"
The BlocTalk of VITA Zahnfabrik is a perfect platform for dentists and dental technicians who deal with this topic. Furthermore, a forum for colleagues, dental technicians, scientists, etc. would be desirable for discussing particular questions or for problem solving.
Editor's note:
Dear Dr. Brunner, thank you for your proposal. Please see our new column "Discussion". We are always glad to receive comments and tips regarding the presented cases as well as general suggestions concerning the VITA BlocTalk. Let us know your opinion and your feedback will immediately be online under the column "Discussion".
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