International Academy for Adhesive Dentistry (IAAD) Dear Members, We are now in the second year of IAAD, so it is time for our secretary to send all members the yearly invoice for their membership fee. Some have not yet paid their 2014 dues and will get a friendly reminder. Please remember, the membership includes a subscription to the Journal of Adhesive Dentistry. If you do NOT want it, then please indicate this on your payment and select the lower membership fee. There were some complaints from members that they were not able to access the Journal of Adhesive Dentistry online. We have fixed this now. Those of you who receive the Journal of Adhesive Dentistry through your IAAD membership will get an e-mail in the next few days explaining the procedure and giving you your Account and Subscriber numbers. With this information, you should be able to set up the necessary tools to access the Journal of Adhesive Dentistry online. The preparations for the BIG EVENT, our 1st Biennial meeting in Orlando on September 11th and 12th, 2015, are proceeding smoothly on schedule. See our website www.adhesivedentistry.org for more details, especially the full program. Because there was little response to our first call for posters, we have extended the deadline to May 30th. Dear Colleagues, submit an abstract for a poster and remember, we are awarding two prizes of $1000 each: “The Presidential IAAD Scientist Award” and the “Fusayama IAAD Scientist Award”. The chances of winning are good, since the pool of candidates so far
is relatively small. Furthermore, Abstracts will be printed in the Journal of Adhesive Dentistry. For instructions and submission, see the IAAD website as well.
See you all in Orlando! Sincerely yours
Jean-François Roulet President, IAAD
Don’t miss the First Biennial Meeting of the IAAD in Orlando on September 11th and 12th, 2015!
Intraoral Repair Protocol for Chipping or Fracture of Veneering Ceramic in Zirconia Fixed Dental Prostheses Mutlu Özcana IAAD WORKING INSTRUCTIONS Question: What is the best intraoral surface conditioning protocol for the repair of chipping or fracture of veneering ceramic in zirconia fixed dental prostheses?
Professor, Dental Materials Unit, Clinic for Fixed and Removable Prosthodontics and Dental Materials Science, Center for Dental and Oral Medicine, University of Zurich, Zurich, Switzerland.
Vol 17, No 2, 2015
Answer: Chipping or fracture of veneering ceramic in a veneered-zirconia fixed dental prosthesis (FDP) may involve framework zirconia exposure. For intraoral repair procedures in such a case, the zirconia framework and the cohesively fractured veneering ceramic need to be
Correspondence: Professor Mutlu Özcan, University of Zurich, Dental Materials Unit, Center for Dental and Oral Medicine, Clinic for Fixed and Removable Prosthodontics and Dental Materials Science, Plattenstrasse 11, CH-8032, Zurich, Switzerland Tel: +41-44-634-5600; Fax: +41-44-634-4305. e-mail: [email protected]
Control occlusion and eliminate premature contacts.
Many factors are responsible for chipping or fractures of veneering ceramic of FDPs, one of which is the presence of premature contacts.5 This could be the underlying cause for failure and should be eliminated prior to repair procedures.
Determine the color of the repair composite.
The color match between ceramic and resin composites especially in the visible anterior areas is crucial, as the two materials have different surface properties and color stability.2
Place rubber-dam and modify it in case of long-span FDPs.
Rubber-dam will protect the soft tissues from hazardous hydrofluoric acid (HF) used later for conditioning the veneering ceramic.6
Clean both the veneering ceramic and exposed zirconia framework surface using fluoride-free paste or pumice.
Etching gels and adhesive promoters should have direct contact with the substrates for effective conditioning. Clean surfaces are essential in all adhesive procedures.
Remove glaze of the veneering ceramic surface at the margins to be repaired using a fine-grit diamond bur under water cooling and create a bevel.
Undisturbed glaze layer with concentrated glass particles will not react with HF and subsequent application of silane coupling agents. Removal of glaze layer increases the surface area on ceramic for mechanical retention and enables the reaction of silane with the glassy matrix.11 The presence of glass phase in ceramics is crucial for better siloxane bonds.13
Coat the veneering ceramic except the bevelled area using glycerine gel.
Accidental deposition of particles during conditioning of the exposed metal by air abrasion may remove the glaze on the veneering ceramic.
Air abrade the zirconia surface using a chairside airabrasion device, preferably with alumina particles coated with silica or silica only (particle size range: 30 to 50 μm; blasting pressure: 2.5 bar) for approximately 20 s in circling motion, rotating the nozzle, until the zirconia surface turns matte from a distance of approximately 10 mm.7 Wash and rinse under copious water and dry throughly.
Air abrasion of the zirconia surface cleans the surface of contaminants and roughens zirconia. The alumina particles present a more amorphous pattern than silica-coated alumina or silica particles which then react with the subsequent silane layer.3 The nozzle distance of approx 10 mm allows the particles to abrade the surface over a greater diameter. If nozzle is not rotated in circling motions, the surface is not evenly roughened.8 Rinsing would remove the particles on the zirconia and ceramic surface and increase wettability of the HF and the silane.
Etch the ceramic margins where the repair composite will be adhered with 5% or 9.6% HF for 20 or 90 s, respectively, depending on the manufacturer’s instructions. Rinse for at least 60 s and dry.
HF selectively dissolves the glass matrix and provides an ideal surface pattern for micromechanical retention.1
Apply silane coupling agent on both the zirconia and the ceramic surface in one layer and wait for its reaction.
Silane coupling agents makes covalent bonds between the silica and oxides present on the zirconia, and silica on the ceramic to the organic matrix of the resin by means of siloxane bonds.13
Apply adhesive resin on both the veneering ceramic and exposed zirconia framework. Air thin the adhesive resin and photopolymerize for 20 s.
Application of adhesive resin increases the wettability of the resin composite.10
Apply resin composite incrementally, photopolymerize. Remove rubber-dam and control the occlusion. Make sure premature contacts are eliminated. Finally, finish and polish the repair composite.
conditioned accordingly.9 Both substrates require different conditioning methods with etching gels, adhesive promoters and/or abrasives. Thus, the sequence of repair protocol may affect durable adhesion of repair composite to these substrates. CAVE: In case of cohesive failures only in the ceramic without zirconia exposure, the steps involving etching with HF, silanization, and adhesive resin application are sufficient. Recently, multimode adhesive systems have also been employed for the repair of veneered zirconia FDPs, but all multimode adhesives require initial air-abrasion procedures.4,12 Thus, physicochemical conditioning protocols are still crucial for the repair of veneer-zirconia complex.
REFERENCES 11. 1. 2.
Calamia JR. Etched porcelain facial veneers: a new treatment modality based on scientific and clinical evidence. NY J Dent 1983;53:255-259. Gresnigt MM, Kalk W, Özcan M. Randomized clinical trial of indirect resin composite and ceramic veneers: up to 3-year follow-up. J Adhes Dent 2013;15:181-190. Guggenberger R. Rocatec system-adhesion by tribochemical coating. Dtsch Zahnärztl Z 1989;44:874-876.
Han IH, Kang DW, Chung CH, Choe HC, Son MK. Effect of various intraoral repair systems on the shear bond strength of composite resin to zirconia. J Adv Prosthodont 2013;5:248-255. Özcan M. Fracture reasons in ceramic-fused-to-metal restorations. J Oral Rehabil 2003;30:265-269. Özcan M, Allahbeickaraghi A, Dündar M. Possible hazardous effects of hydrofluoric acid and recommendations for treatment approach: a review. Clin Oral Investig 2012;16:15-23. Özcan M. Air abrasion of zirconia resin-bonded fixed dental prostheses prior to adhesive cementation: why and how? J Adhes Dent 2013;15:394. Özcan M, Raadschelders J, Vallittu P, Lassilla L. Effect of particle deposition parameters on silica coating of zirconia using a chairside airabrasion device. J Adhes Dent 2013;15:211-214. Özcan M, Valandro LF, Pereira SM, Amaral R, Bottino MA, Pekkan G. Effect of surface conditioning modalities on the repair bond strength of resin composite to the zirconia core / veneering ceramic complex. J Adhes Dent 2013;15:207-210. Passos SP, Valandro LF, Amaral R, Özcan M, Bottino MA, Kimpara ET. Does adhesive resin application contribute to resin bond durability on etched and silanized feldspathic ceramic? J Adhes Dent 2008;10:455-460. Sarac YS, Kulunk T, Elekdag-Turk S, Sarac D, Turk T. Effects of surfaceconditioning methods on shear bond strength of brackets bonded to different all-ceramic materials. Eur J Orthod 2011;33:667-672. Seabra B, Arantes-Oliveira S, Portugal J. Influence of multimode universal adhesives and zirconia primer application techniques on zirconia repair. J Prosthet Dent 2014;112:182-187. Söderholm KJM, Shang SW. Molecular orientation of silane at the surface of colloidal silica. J Dent Res 1993;72:1050-1054.
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