Styleitaliano is a FREE website, help us to give you the best contents by telling us who you are and what you like.
If you are already registered, just write your mail and continue
Email not registered. Please fill the gaps to continue.

Thank you!
This e-mail address is already registered, click continue to see the content

Email:
First Name:
Last Name:
Country:
Primary profesional interest:







Continue
Continue
x

11598 Views - Nov 2015

Download PDF
Are you unsatisfied of being unable to apply CAD-CAM technology in your daily practice? The first time we tried to do a chair side restoration, it was not as easy as promised by many. Finally a brainstorming from the Styleitaliano group opened my mind to follow a feasible method to be able to take the best of the latest technologies and in the less time as possible.

Few time and high quality are two characteristics we would like for any of our restorations, especially for the indirect ones, laboratory steps many times impede this, especially regarding time. CAD-CAM enthusiasts claim this is extremely easy and many people felt exactly the opposite in the first contact with this technology. In other words, expending a horrible amount of time.

The styleitaliano team propose a Feasible method for CAD-CAM restorations, thinking 360º not only regarding clinical timing but as well quality and economics.

Now-a-days the digital dentistry has overcome many problems, especially regarding the precision issues and the speed of the impression time.

Partial indirect restorations are the state-of-the-art when projecting cusp protection, margin adaptation, aesthetics and most of all tissue conservation.


An everyday case that needs a fast and routine treatment, granting the highest quality should be treated with a trustworthy protocol. Initial situation, a patient comes after endo treatment with a temporary composite on the mesial of the tooth 16. The contact point from the previous restoration was impending the floss passing.
In order to make the rubber dam pass passively we opened the medial part of the old restoration. The rubber dam is placed and invaginated properly. Immediately after we remove all of the old composite and proceed with a new build-up with a dentin A2 (Filtek Supreme XTE).
After removing the rubber dam immediately we prepare 2mm occlusal, in order to give the right space for an indirect restoration. Without entering in debt with ultra thin restorations, the ultimate clinical and in-vitro evidence are into these thickness values in various aesthetic materials.
Distal ridge was decided to be removed because of a distal enamel decay. Margins were taken to the zone where we meet the wedge, this area gives us plenty of security, meaning that is an area easily accessible with probes, proxa-brush, dental floss, etc.. not only during cementation stage, but as well in the future controls and follow-ups. It is said that partial coverage of posterior teeth can lead to destructive preparation of teeth, the state-of-the-art preparation which is a mixture of old techniques, some of them even from the gold era, reside on the quest of: 1 Thickest enamel margins, 2 Accessibility of all the margins, 3 Minimum space, 4 Flat surfaces, 5 Unique Geometrical positioning
After removing the wedges and rubber dam, is very likely to have bleeding gums. In order to stop the bleeding, it is suggested to use an hemostatic agent (Astringent paste 3M ESPE). After letting it act for 5 minutes it can be generously rinsed with water and air.
Operating area is slightly powdered with CAD-CAM contrasting agent and the intra-oral scanning is performed (TrueDef). The patient is dismissed for 30 minutes into the waiting room.
Simple tools have been developed to help the clinician to carry out the impressions, which require different skills and movements from the conventional silicone impressions. The Styleitaliano team together with “Smile Line” developed under the guidance of Dr. Gaetano Paolone a series of soft tissue retractors called Photo-CAD, especially designed to separate in the lower arch the tongue and the cheek at the same time (Photo-CAD LOW), and in the upper arch to be able to separate the cheek in its full length up to the second and third molar (Photo-CAD UP). The name Photo-CAD comes from the ability to act as a retractor for Photography and for the CAD impression (Computer Assisted Design).
The STL file is immediately sent to the trusted laboratory (Giuseppe Mignani, Bologne). In the mean time the clinician is entitled to do other tasks. In the classical approach, either the dentist should design or outsource the full work, wasting a lot of time in either situation.
The antagonist and their relationship are recorded as well in very little time and received by the laboratory.
It requires few time to set a fast digital workflow between the lab and the clinic, as soon as the lab receives the file, the 3D design is done rather quickly, in about 20 minutes the file goes back and forth with the final design.
Immediately after receiving the file, in this case, the restoration was milled -in-house- so depending on the machine, the time of finalisation varies. Modern materials as Lithium disilicate are used frequently to perform this kind of treatments with superb results, but as well since many years, the best alternative to the ceramic restorations has been the laboratory made composite, due to many reasons as the softness of the material and its respect to the natural enamel of the antagonist, but most of all the kindness of this material is the capability it has to be maintained and repaired, superior to any other material. LAVA ultimate was chosen for this case because it has the same and better properties as a laboratory processed composite.
Characterisation phase (stains) and polishing are done, rather fast, enhancing the anatomy with sharper burs, creating a sulcus with super sharp 4 edged bur, inserting stains and polishing. This phase was done by Mr. Giuseppe Mignani.
The overlay is fitted and adjusted proximally (if necessary). If the fitting is good we can proceed to field isolation and cementation.
Contact points must be veryfied and corrected with an abrasive rubber point until complete settlement of the restoration is achieved, full stability and marginal fit.
CAD-CAM restorations are rather precise, and require few adjustments. At this stage, of course, color does not seem to integrate. After cement filling, the light will pass more effectively and the margin will likely disappear.
The quadrant isolated and ready to perform the cementation steps.
Sandblasting of the restoration is performed immediately after the build-up will be sandblasted intra-orally with 2bars pressure and 50 micron Al2O3 within at least 5 centimeters form the surface.
After carefully sandblasting the composite build-up with the neighbor teeth protected with partial matrices and making special attention to properly sandblast the deep margin elevation material, we will perform selective acid etching of the enamel with 37% phosphoric acid during 15 seconds.
The cavity is treated with a self-etch universal bonding system (Scotchbond Universal, 3M ESPE) and the solution is brushed during 20 seconds and left during 40 seconds undisturbed in order to act properly in the dentin, immediately after with air the excess of material will be removed. Do not polymerize.
The same adhesive is placed in the inside of the restoration and excess is removed in the same way mentioned above.
Dual curing cement is applied in the inside of the restoration.
The cement excess flowing through the margins on the first fitting of the restorations.
With a small instrument (Fissura, LM Arte, LM instruments, Parainen, Finland) the excess is removed from all the margins, including the interproximal.
With a rounded condenser (Condensa, LM Arte, LM instrumetns, Parainen, Finland) the restoration is held in place, not often extra excess might come out. Floss is passed in the distal and medial area.
If the restoration is stable we will remove the excess with a brush.
Extended polymerization is done.
Polymerized invisible excess is taken out with a sharp instrument (Eccesso, LM Arte, LM instruments, Parainen, Finalnd) taking much attention especially to the proximal area.
The final aspect of the freshly cemented restoration.
Occlusion prediction from the machine required minimum intervention.
Final aspect of the restoration.
One month control. The amalgam restoration will be replaced later on.
Vestibular integration, which is rather good, especially given the fact that the tooth is slightly discoloured. Working with mono-mass choosing the right opacity is a very reliable procedure aesthetically speaking.

Conclusions

CAD-CAM restorations managed properly offer an extra performance, not only in terms of the final quality of the material, but smartly planned, can be economically and ergonomically convenient. Indirect milled composite show excellent handling and physical properties. The use of special instruments during digital intraoral impressions facilitates the task in a very important way.
 

Bibliography

References

- Zarow M(1), Devoto W, Saracinelli M. Reconstruction of endodontically treated posterior teeth--with or without post? Guidelines for the dental practitioner. Eur J Esthet Dent. 2009 Winter;4(4):312-27.
- Asmussen E. Factors affecting the color stability of restorative resins. Acta Odontol Scand 1983; 41 (1):11-18.
- Bailey LF, Bennet RJ. DICOR surface treatments for enhanced bonding. J Dent Res 1988; 67: 925-931.
- Barghi N. To silanate or not to silanate: making a clinical decision. Compend Contin Educ Dent 2000; 21:659-662, 664.
- Berrong JM, Weed RM, Schwartez IS. Color stability of selected dual cure composite resin cement. J Prosthodont 1993; 2: 24-27.
- Bertolotti RL, Lacy AM, Watanabe LG. Adhesive monomers for porcelain repair. Int J Prosthodont 1989; 2:483-489.48
- Blatz MB. Long-term clinical success of all-ceramic posterior restorations.
- Breschi L, Cammelli F, Visintini E, Mazzoni A, Vita F, Carrilho M et al. Influence of clorhexidine concentration of the durability of etch-and-rinse dentin bonds: a 12 months in vitro study. J Biomed Mater Res B Appl Biomater 2003; 66: 287-298.
- Breschi L, Mazzoni A, Ruggeri A, Cadenaro M, Di Lenarda R, De Stefano et al. Dental adhesion review: aging and stability of the bonded interface. Dent Mater 2008 Jan; 24 (1): 90-101.
- Carrilho MRO, Carvalho RM, deGoes MF, di Hipolito V, Geraldeli S, Tay FR et al. Clorhexidine preserves dentin bond in vitro. J Dent Res 2007a; 86 (1): 90-94.
- Carrilho MRO, Geraldeli S, Tay FR, deGoes MF, Carvalho RM, Tjaderhane L et al. In vivo preservation of the hybrid layer by clorhexidine. J Dent Res 2007b; 86 (6): 529-533.
- Chen JH, Matsumura H, Atsuta M. Effect of different etching periods on the bond strength of a composite resin to a machinable porcelain. J Dent 1998a; 26: 53-8.
- Cohen RG, Razzano MV. Immediate dentin sealing using an antibacterial self-etching bonding system. Pract Proced Aesthet Dent 2006 Oct; 18 (9): 561-565.
- D’Arcangelo C, Vanini L. Effect of three surface treatments on the adhesive properties of indirect composite restorations. J Adhes Dent 2007 Jun; 9 (3): 319-326.
- Donly KJ, Jensen ME, Triolo P, Chan D. A clinical comparison of resin composite inlay and onlay posterior restorations and cast-gold restorations at 7 years.
- Ferracane JL, Condon JR. Post-cure heat treatments for composites: properties and fractography. Dent Mater 1992 Sep; 8 (5): 290-295.
- Hummel SK, Marker V, Pace L, Goldfogle M. Surface treatment of indirect resin composite surfaces before cementation. J Prosthet Dent 1997 Jun; 77 (6): 568-572.
- Imazato S, Tarumi H, Kobayashi K, Hiraguri H, Oda K, Tsuchitani Y. Relationship between the degree of conversion and internal discoloration of light-activated composite. Dent Mater J 1995 Jun; 14 (1): 23-30.
- Kern M, Schaller HG, Strub JR. Marginal fit of restorations before and after cementation in vivo. Int J Prosthodont 1993 Nov-Dec; 6 (6): 585-591.
- Magne P. Immediate dentin sealing: a fundamental procedure for indirect bonded restorations. J Esthet Restor Dent 2005; 17 (3): 144-154.
- Magne P. Composite resins and bonded porcelain: the postamalgam era? J Calif Dent Assoc 2006 Feb; 34 (2): 135-147.

- Ozcan M, Barbosa SH, Melo RM, Galhano GA, Bottino MA. Effect of surface conditioning methods on the microtensile bond strength of resin composite to composite after aging conditions. Dent Mater 2007 Oct; 23 (10): 1276-1282.
- Park SH. Comparison of degree of conversion for light-cured and additionally heat-cured composites. J Prosthet Dent 1996 Dec; 76 (6): 613-618.
- Peutzfield A. Indirect resin and ceramic system. Oper Dent 2001; suppl. 6: 153-176.
- Reinhardt JW, Boyer DB, Stephens NH. Effects of secondary curing on indirect posterior composite resins. Oper Dent 1994 Nov-Dec; 19 (6): 217-220.
- Swift EJ Jr, Brodeur C, Cvitko E, Pires JA. Treatment of composite surfaces for indirect bonding. Dent Mater 1992 May; 8 (3): 193-196.
- Uçta li S, Wilson HJ, Zaimo lu L. Variables affecting the fracture toughness of resin-based inlay/onlay sys- tems. J Oral Rehabil 1993 Jul; 20(4): 423-431.
- Valandro LF, Pelogia F, Galhano G, Bottino MA, Mallmann A. Surface conditioning of a composite used for inlay/onlay restorations: effect on muTBS to resin cement. J Adhes Dent 2007 Dec; 9 (6): 495-498.

ASK THE AUTHOR PRIVATELY





Privacy Policy