Cementation Procedures for Ceramics
9
Matthias Kern, dmd, phd
Restorations made from weaker silica-based ceramics need to be adhesively luted to obtain sufficient strength.1 In contrast, restorations made from reinforced silicate ceramics such as lithium disilicate or those made from oxide ceramics can be cemented either with adhesive luting resins2,3 or with conventional cements.4,5 There is no evidence to date that adhesive luting of crowns made from reinforced silicate ceramics or high-strength oxide ceramics will improve their clinical outcome.5–7 However, in cases presenting limited abutment retention, adhesive cementation can be assumed to be advantageous. In addition, adhesive luting techniques are required for restoration types that present limited or no mechanical retention, such as labial or occlusal veneers (“table tops�),8 partial-coverage restorations, or Maryland-type fixed dental prostheses (FDPs).9,10 Moreover, luting resins present good to excellent translucency, not leaving the opaque cementation lines that are exhibited when conventional cements (eg, zinc phosphate and glass-ionomer cements) are used. These resins also minimize microleakage when the correct dentin adhesives are used.11 The purpose of this chapter is to describe conventional and adhesive cementation techniques for high-strength ceramics, elucidating their specific requirements as well as their possible sources of error.
Conventional Cementation Due to their strength, complete-coverage restorations made from reinforced silicate ceramics or high-strength oxide ceramics can be cemented with conventional cements such as zinc phosphate cement or glass-ionomer cement.5,12,13
Abutment preparation Conventional cementation techniques are less time-consuming and less technique sensitive under clinical conditions than most of the adhesive
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Cementation Procedures for Ceramics luting techniques. However, conventional cementation requires complete-coverage restorations and adequate retentive preparation of the abutment teeth. Loss of retention is one of the most frequent causes for clinical failure of posterior metal-based FDPs.14–17 The dislodgment of cast posterior restorations was strongly associated with a lack of resistance form in the preparations; ie, dislodged restorations came mostly from preparations with tapers that did not provide resistance form.18 Provided that an adequate finishing line such as a shoulder or chamfer is used for all-ceramic restorations,19 it has been recommended that the abutment tooth preparation for complete-coverage all-ceramic restorations made from lithium disilicate or high-strength oxide ceramics follow the already established preparation guidelines for metal-based crowns20,21 in order to achieve an adequate retention and resistance form that will resist the dislodgment of the restorations from their abutments. In addition, abutment surface roughness is needed to retain conventional cements. Therefore, abutment preparation should be finished with the use of fine-grain diamond instruments (International Organization for Standardization standard 504), which produce a surface roughness of about 15 µm. Use of finer diamond instruments might reduce cement retention.22 To succeed in conventional cementation, the clinician should protect the dental pulp. To protect the pulp of vital abutment teeth, a freshly mixed suspension of calcium hydroxide can be applied with a rotating rubber cup to block the dentinal tubules.23–25 Alternatively, resin-based sealing systems can be used.26 However, their effect on crown retention is not fully understood.27,28 In general, unfilled or low-filled sealers seem to be more suitable than highly filled sealers, because they create a thicker sealing layer and will smooth the retentive surface. Because long-term clinical results regarding the combination of resin-based sealers and conventional cements are unknown, the routine application of calcium hydroxide prior to conventional cementation is still most often recommended.21,25
Restoration surface preparation Like the abutments, the inner surfaces of completecoverage restorations made from lithium disilicate and high-strength oxide ceramics should be roughened prior to conventional cementation to obtain optimal cement retention. Lithium disilicate ceramic restorations should be etched with 5% hydrofluoric acid for 20 seconds5 (Fig 9-1a), while high-strength oxide ceramics should be air-abraded with 50-µm alumina particles used at 2.5-bar pressure or less.4 However, whether airborne particle abrasion alters the strength of high-strength ceramic restorations on a 174
clinically significant level is still controversial. While some studies have shown a strengthening effect of airborne particle abrasion on oxide ceramics,29–32 others have reported a strength-reducing effect.33–35 The pressure used for air abrasion might be clinically significant. While surface roughness of zirconia ceramic increases with increasing air pressure, the flexural strength decreases with increasing pressure, which has been tested at pressures of 2, 4, and 6 bars.36 Therefore, use of 50-µm alumina particles with a pressure of 2.5 bars or less is recommended to minimize subsurface damage of the ceramic but still provide adequate retention for conventional cements.37 To date there are no controlled clinical studies showing whether airborne particle abrasion influences the clinical outcome of high-strength oxide ceramic restorations positively or negatively. This topic is discussed separately, later in the chapter, because of its controversy and relevance.
Cementation procedures For patients with vital abutment teeth with increased sensitivity, administration of local anesthesia prior to the cementation procedure is sometimes recommended. The area of cementation is isolated with cotton rolls, a saliva evacuator, and, when indicated, retraction cords if the preparation margin is subgingival. The abutments are cleaned thoroughly using a rotating rubber cup with a slurry of fine pumice followed by water spray (Fig 9-1b). The teeth should be dried gently with cotton rolls or special absorbent strips. The teeth should not be overdried, because this may lead to postoperative sensitivity. The cement for any conventional cementation is mixed in accordance with the manufacturer’s instructions. The author prefers glass-ionomer cement in capsules for trituration mixing in a high-speed mixing machine. The capsules can be stored in a refrigerator and taken out directly prior to mixing, which prolongs the clinical working time considerably. A disposable brush is used to coat the clean but conditioned inner surfaces of the all-ceramic restorations with a thin layer of the freshly mixed cement. The complete internal surface and margins of the restoration should be coated. The restoration is seated with firm, gradually increasing pressure until complete seating is achieved. Correct seating of the restoration is checked with an explorer on several easily accessible marginal locations. When posterior restorations are cemented, the patient can be asked to bite on cotton rolls to keep the restoration in the correct position. In the anterior region, the operator should retain the restoration in its correct position using firm finger pressure until the cement has fully set.
Adhesive Cementation
a
b
c
d
Fig 9-1  (a) Etching of a lithium disilicate crown with 5% hydrofluoric acid for 20 seconds (for etching pattern, see Fig 9-2a). (b) Cleaned abutment tooth prior to conventional cementation. (c) Complete hardening of conventional glass-ionomer cement prior to removal of excess cement. (d) Conventionally cemented lithium disilicate crown.
During setting, the cement should be protected from drying out and from excessive moisture (Fig 9-1c). When it has fully set, the excess cement at the restoration margins is removed with an explorer and dental floss with a small knot. Optional retraction cords are removed, and the occlusion is checked in both centric occlusion and excursive movements and corrected when necessary (Fig 9-1d). After any occlusal adjustment, the ceramic surface must be polished meticulously following the recommendations of the manufacturer.19
Adhesive Cementation Suggested bonding methods When adhesive cementation is used, the created bonding interfaces should not only provide mechanical stability but also prevent microleakage, which is achieved through
physicochemical bonding systems. As a first step, the ceramic bonding surface is chemically or micromechanically roughened and therefore enlarged. Simultaneously, the surface is cleaned thoroughly and chemically activated. In a second step, the activated surface is conditioned with a primer (adhesive monomer), which promotes chemical bonding between the surface oxides and the double bonds of the luting resin. Some resins already contain adhesive monomers effective on oxide ceramics, so that no additional primer is needed; the Panavia product group (Kuraray), for example, contains 10-methacryloyloxydecyl dihydrogen phosphate (MDP). Without adequate ceramic surface roughening and activation, bonded specimens usually debonded spontaneously during artificial aging.38–43 For predictable and durable resin bonding, it is essential to condition the ceramic surface restoration only after all try-in procedures with the definitive restoration have been completed, because typical dental cleaning methods are 175
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Cementation Procedures for Ceramics TABLE 9-1 Typical composition of popular high-strength ceramics (wt%)* Product Oxide
Lithium disilicate ceramics e.max Press
e.max CAD
Glass-infiltrated oxide ceramics In-Ceram Alumina Classic
In-Ceram Zirconia Classic
Glass-free oxide ceramics In-Ceram 2000 AL Procera Alumina
Cercon IPS e.max ZirCAD In-Ceram 2000 YZ Lava Procera Zirconia Zerion
Silicon dioxide (SiO2)
57–80
57–80
4–5
3–4
—
—
Lithium oxide (Li2O)
11–19
11–19
—
—
—
—
Potassium oxide (K2O)
0–13
0–13
—
—
—
—
Phosphorus pentoxide (P2O5)
0–11
0–11
—
—
—
—
Aluminum oxide (Al2O3)
—
0–5
82
57
> 99.9
—
Zirconium dioxide (ZrO2)
0–8
0–8
—
26
—
95–97
Yttrium oxide (Y2O3)
—
—
—
<2
—
3–5
Lanthanum oxide (La2O3)
—
—
12
7
—
—
0–10
0–8
1–2
5–6
< 0.1
<3
Others
*Data provided by the manufacturers. In-Ceram materials, Vident; Cercon, Dentsply; e.max materials, Ivoclar Vivadent; Procera, Nobel Biocare; Lava, 3M ESPE; Zerion, Straumann.
a
b
Fig 9-2 (a) Scanning electron micrograph (SEM) of the surface of lithium disilicate ceramic (e.max Press, Ivoclar Vivadent) after etching with 5% hydrofluoric acid for 20 seconds. A distinct etching pattern is noticeable. (b) SEM of the surface of lithium disilicate ceramic (e.max Press) after etching with 5% hydrofluoric acid for 60 seconds. The etching pattern is more pronounced, but crystals on the top surface are nearly completely exposed, which will weaken their bond to the bulk material.
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Adhesive Cementation TABLE 9-2 Recommended bonding methods to high-strength dental ceramics Functional steps
Lithium disilicate ceramics
Oxide ceramics
Cleaning, roughening, and chemical activation
Etching with 5% hydrofluoric acid for 20 s
Air abrasion with 50-µm alumina particles at 0.5 to 2.5 bar
Chemical coupling/bonding
MPS-containing primer
MDP monomer containing luting resin
Luting
Any dental luting resin
or
MDP monomer or phosphorylated methacrylates containing primer Any dental luting resin
MDP, 10-methacryloyloxydecyl dihydrogen phosphate; MPS, 3-methacryloxypropyltrimethoxysilane.
a
b
Fig 9-3 (a) SEM of the surface of densely sintered zirconia ceramic (e.max ZirCAD, Ivoclar Vivadent) after machining without surface conditioning. Note the grooves and surface irregularities caused by the milling procedure. (b) At higher magnification, the crystal boundaries are detectable.
not suitable to completely remove organic contamination resulting from contact with saliva, blood, or silicone disclosing media.3,44–46 When appropriate bonding systems are used correctly on high-strength ceramics, bond strengths in the magnitude of 30 N/mm² (30 MPa) are achieved routinely,2,3 which corresponds to the bond strength achieved on acid-etched enamel.47 To illustrate the high strength of resin-bonded allceramic restorations, the total bond strength of a veneer or retainer wing for Maryland-type FPDs with a typical bonding area of 30 mm² can be calculated to be in the magnitude of 900 N (30 N/mm² × 30 mm²), which corresponds to a weight load of 90 kg (approximately 198 lb). When high-strength ceramics are conditioned for adhesive cementation, their composition is of outmost importance to the selection of an optimal roughening and an optimal chemical bonding method. Because of the glass matrix and the high content of silica in lithium disilicate ceramic (Table 9-1), it can be acid etched with hydrofluoric acid to achieve a clean and roughened microretentive surface texture.19 Then 3-methacryloxypropyltrimethoxysilane
(MPS) can be used to effectively promote bonding.3,48 Etching time can be reduced to 20 seconds (Fig 9-2), compared with the 60 seconds required for low-strength silica ceramics.3,49,50 Effective bonding to lithium disilicate ceramics is achieved by hydrofluoric acid etching followed by silanization (Table 9-2). In contrast, current high-strength dental oxide ceramics consist mostly of alumina, zirconia, and/or yttria and often do not contain any glassy phase (see Table 9-1). Due to these differences, bonding methods used for silica-based ceramics (eg, lithium disilicate) are not suitable for oxide ceramics.1,2 Use of hydrofluoric acid to etch oxide ceramics does not create adequate surface roughness for resin bonding51,52 (Fig 9-3). In addition, organosilanes used for silica-based ceramics might help in surface wetting of oxide ceramics51 but do not promote adequate bonding to alumina or zirconia ceramics.38,53–55 Therefore, different bonding techniques than those used for lithium disilicate ceramics have to be used for oxide ceramics such as alumina and zirconia.2
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Cementation Procedures for Ceramics
a
b
Fig 9-4 (a) SEM of the surface of densely sintered zirconia ceramic (e.max ZirCAD) after air abrasion with 50-µm alumina particles at 1 bar for 15 seconds. Remnants from the air abrasion procedure were removed by ultrasonic cleaning in 99% isopropanol for 3 minutes. There is a clearly visible increase in surface irregularities compared with Fig 9-3. (b) Higher magnification reveals surface cracks.
H
2
C H
C
3
C C
O
O
H
H
H
2
2
2
H
C H
2
C H
2
C H
2
2
C
H
C 2
H
H2C
2
2
H
C O P
HO
2
2
O
H
C H
2
C H
2
C H
2
C H
2
C
C
2
C O
O H
O H
O H
Oxide ceramic
Fig 9-5 Suggested chemical bonding of the bifunctional phosphate monomer MDP to oxide ceramics.
178
2
C
P O H
C H
H2C
– 2 H2O
O H
2
+ O H
O
O
C
C H
3
C
C
C H
H
C H
C
O
O
O
Oxide ceramic
O H
Adhesive Cementation Fig 9-6 Colored zirconia ceramic with protective acrylic resin cover in place prior to air abrasion.
Bonding to unconditioned oxide ceramic surfaces (as produced from manufacturing a restoration) after cleaning with isopropanol did not result in durable bonds.38,40,42,43,56 However, numerous studies have found that the gold standard in bonding to oxide ceramics consists of air abrasion for roughening, cleaning, and chemical activation followed by the use of specific adhesive monomers.2 Air abrasion with 50- to 110-µm alumina particles at pressures of 0.5 to 2.5 bars (Fig 9-4) has been found to be effective in cleaning and roughening the surface of alumina and zirconia ceramics.38,40,43,53,54,57–59 The substance loss caused by airborne particle abrasion does not significantly alter the clinical fit of dental oxide ceramic restorations.57 Numerous laboratory studies of oxide ceramics also have shown that phosphate monomer–containing composite resins and primers provide a high and durable resin bond to these ceramics when used after air abrasion of the ceramic bonding surface (for overview, see Kern2). One phosphate monomer that has been confirmed to consistently promote chemical bonds to oxide ceramics is MDP,
containing a phosphate ester group and a methacrylate group60 (Fig 9-5).Other luting resins and primers that contain either 4-methacryloxyethyltrimellitate anhydride or phosphorylated methacrylates also have shown promising results when used on air-abraded oxide ceramics.39,42,43,59,61–64 Use of phosphate monomers on air-abraded zirconia is simple, and the technique can be used chairside without requiring extra laboratory work, as some other methods do (see the upcoming section, “Controversies in Adhesive Cementation”). In addition, it is the only method that has been proven to be clinically successful for inlay-retained FDPs65 and single-retainer resin-bonded FDPs.9,10 To ensure complete abrasion of the bonding surface, it can be colored with a permanent marker, which is then completely removed by air abrasion66 (Fig 9-6). Any veneering ceramic must be protected from air abrasion with a protective resin coating or other means. The recommended bonding methods for high-strength ceramics are listed in Table 9-2. The recommendations are based on the aforementioned evidence. 179
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Cementation Procedures for Ceramics
a
b Fig 9-7â&#x20AC;&#x201A; (a) Resin-bonded FDP after removal of excess resin and application of an oxygen inhibition gel. (b and c) Single-retainer resin-bonded zirconia ceramic FDP.
c
Clinical procedures for luting of resinbonded FDPs and occlusal veneers After the application of a rubber dam, the enamel bonding surface is cleaned thoroughly with a rotating rubber cup and a slurry of fine pumice followed by water spray. Alternatively, sodium or calcium carbonate air polishing can be used to clean enamel surfaces, but this should not be used on dentin because it would compromise dentin bonding.67 Enamel is etched with 37% phosphoric acid in gel form for 30 seconds. Adjacent teeth should be protected with plastic barriers. The etching gel is removed by water spray, and the bonding surfaces are air dried. In areas of locally exposed dentin, a dentin adhesive compatible to the luting resin is applied. For adhesive cementation, tooth-colored transparent self-curing or dual-curing luting resins are used after the ceramic surface is conditioned adequately as already described. With many luting resins, an unfilled or low-filled 180
bonding agent is applied first to the conditioned ceramic surface and to the etched enamel surfaces and thinned with a stream of compressed air. Because of their low viscosity, resins of the Panavia product group (eg, Panavia 21 TC or Panavia F 2.0 TC) can be used without additional bonding agent on ceramic and on enamel. The luting resin is mixed in accordance with the manufacturerâ&#x20AC;&#x2122;s instructions, and then a disposable brush is used to completely coat the bonding surfaces of the all-ceramic restorations with a thin layer of the luting resin. The restoration is seated with finger pressure until complete seating is achieved. While the operator retains the restoration in its correct position, the dental assistant can remove any accessible excess resin using disposable brushes, foam pellets, and dental floss. An oxygen inhibition gel is applied to the restoration margins to avoid oxygen inhibition of polymerization (Fig 9-7a). In the case of dual-polymerizing resins, additional light curing is applied. This is essential to achieve
Adhesive Cementation
a
b
c
d
Fig 9-8â&#x20AC;&#x201A; (a) Cleaned abutment tooth after placement of a thin retraction cord. (b) Application of a dentin primer (ED Primer, Kuraray). (c) Application of a thin layer of mixed luting resin (Panavia 21 TC). (d) Seating of the zirconia ceramic crown with firm, gradually increasing pressure.
optimal polymerization and best physical properties.68 After the oxygen inhibition gel is removed with water spray, the margins are checked for excess resin, which, if detected, is removed with scalers, diamond burs, and/or finishing disks (Figs 9-7b and 9-7c).
Clinical procedures for luting of all-ceramic crowns and FDPs The abutment teeth are prepared as described for conventional cementation but without use of calcium hydroxide suspension for pulpal protection, because the dentin adhesive will seal the dentin and therefore provide pulpal protection itself.11 If restoration margins are subgingival, a thin retraction cord should be placed in the sulcus to simultaneously prevent both contamination by sulcular fluid and subgingival accumulation of excess resin (Fig 9-8a). After the conditioning of the ceramic bonding surfaces and the
application of the product-specific dentin adhesive/dentin primer (Fig 9-8b) (in the Panavia product group, only the self-etching ED Primer is used), the luting resin is mixed following the manufacturerâ&#x20AC;&#x2122;s instructions and applied to the ceramic bonding surfaces in a thin layer (Fig 9-8c). The restoration is seated with firm, gradually increasing pressure until complete seating is achieved (Fig 9-8d). Correct seating of the restoration is checked with an explorer on several easily accessible marginal locations. While the operator holds the restoration in place, the dental assistant removes any excess luting resin using foam pellets and dental floss (Figs 9-8e and 9-8f ). An oxygen inhibition gel is applied to the restoration margins (Fig 9-8g). When a dual-curing luting resin is used, additional light curing is applied. After full polymerization, the retraction cords are removed (Fig 9-8h), the excess cement is removed, and the occlusion is checked and corrected when necessary (Figs 9-8i and 9-8j). 181
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Cementation Procedures for Ceramics
e
f
g
h Fig 9-8â&#x20AC;&#x201A; (cont) (e) Removal of excess luting resin with foam pellets. (f ) Use of dental floss to remove remaining excess luting resin. (g) Application of an oxygen inhibition gel (Oxyguard, Kuraray). (h) Removal of the retraction cord. (i) Completed restoration on the day of luting. (j) Restoration 5 months after adhesive luting. Note the healthy gingiva.
i
j
182
Controversies in Adhesive Cementation
a
b
Fig 9-9 (a) SEM of the nanostructured alumina-coated zirconia ceramic surface, showing a dense, uniform coating. (b) Higher magnification reveals the nanostructured coating, composed of irregular lamellaes.
Controversies in Adhesive Cementation Air abrasion of oxide ceramics Over the years, whether air-borne particle abrasion alters the strength of oxide ceramic restorations to a clinically significant extent has been a controversial subject. As mentioned earlier, some studies have shown air-borne particle abrasion to have a strengthening effect on oxide ceramics,29–32 while others have reported a strength-reducing effect.33–35 There is no published clinical evidence yet showing whether air-borne particle abrasion influences the clinical outcome of dental oxide restorations negatively. However, medium- and long-term studies on resin-bonded oxide ceramic FDPs revealed no deleterious effect of air abrasion on the bonding surfaces of the retainers over up to 15 years’ observation time.9,10 Nevertheless, it might be advantageous to minimize surface defects by using smaller particles for air abrasion and/ or reducing the blasting pressure (Fig 9-9). Various laboratory results have shown that air abrasion of zirconia ceramic
with 50-µm alumina particles at 0.5-bar pressure reduced the surface roughness compared with air abrasion with standard pressure of 2.5 bars, without compromising resin bonding when appropriate luting resins or primers were used.42,43,69 Thus, air abrasion with reduced blasting pressure seems to be a simple and safe surface conditioning method for oxide ceramics.
Alternative bonding methods Alternative surface conditioning methods for lithium disilicate ceramics include air abrasion, tribochemical silica coating, and alternative etchants.70–72 Air abrasion and tribochemical silica coating have the potential to severely damage restoration margins and therefore cannot be recommended. Lithium-based all-ceramic specimens treated with aqueous titanium tetrafluoride (TiF4) solution exhibited initial shear bond strength values that were similar to those of specimens etched with commonly used hydrofluoric acid when, in a preliminary laboratory study, no artificial aging of the bonded specimens was used.72 However, in a recent study with long-term artificial aging, resin bonding after lithium disilicate ceramic was etched with aqueous TiF4 solution was not durable over time.73
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Cementation Procedures for Ceramics Other alternative surface conditioning methods for oxide ceramics include silanation,2 silanization plasma spraying with hexamethyl disiloxane,55 application of a low-fusing porcelain pearl layer,55 nanostructured alumina coating,74,75 selective infiltration etching,76–78 and various other, in part patented, modified zirconia ceramic surfaces.79,80 In creating microretention and/or the bonding basis for silane coupling agents, these methods seem to be quite effective (see Fig 9-9). However, clinicians might reasonably question why complicated, time-consuming, and/or costly procedures should be used when simple chairside methods with proven clinical effectiveness are already available, that is, air abrasion followed by application of phosphate monomer, as described earlier.
Cleaning methods after clinical try-in In addition, it remains unclear to what extent ceramic bonding surfaces conditioned in the dental laboratory can be negatively altered by the clinical try-in procedures, which result in unavoidable contamination, or by clinically needed surface adjustments to improve the internal fit of the restorations. During clinical try-in of the definitive high-strength ceramic restoration, the ceramic bonding surface usually is contaminated by saliva, blood, and/or silicone fit-checkers. Residual organic and silicone contaminants will compromise bonding and therefore must be removed from the surface before chemical bonding can take place.3,45,46,69,74,81,82 Hydrofluoric acid etching has shown to be the most effective cleaning method for lithium disilicate ceramics,3 while phosphoric acid etching, cleaning in 96% isopropanol, or use of an air polishing device with sodium bicarbonate was far less effective. Therefore, it does not sound reasonable to condition lithium disilicate ceramic restorations in the dental laboratory prior to clinical try-in. Instead, only after successful try-in of a lithium disilicate ceramic restoration should it be acid etched with 5% hydrofluoric acid for 20 seconds and silanized. In contrast, air abrasion with alumina particles was the most effective cleaning method for zirconia ceramic.46,69,82 Water spray, alcohol, and acetone were ineffective cleaners for removal of organic contaminations, while phosphoric acid etching provided some cleaning effect but was far inferior to air-borne particle abrasion.45,46 Therefore, it is recommended that air abrasion with alumina particles be used directly prior to bonding and that the bonding surface not be conditioned prior to clinical try-in.66 Recently, a commercially available cleaning paste (Ivoclean, Ivoclar Vivadent) has been introduced to remove organic contaminants from conditioned ceramic bonding
184
surfaces.83 However, independent data on its efficiency to remove organic contaminants are not yet available.
Conclusion The reviewed literature reveals a vast amount of laboratory bonding studies on silica-based and oxide ceramics that suggest that durable bonding is achievable. However, in contrast to the studies on bonding to silica-based ceramics, long-term clinical studies on bonded high-strength oxide ceramic restorations without mechanical retention are inconclusive. Therefore, clinical trials with bonded oxide ceramic restorations without mechanical retention are needed to verify whether a specific bonding method can provide long-term durable adhesion under the humid and stressful oral conditions.
Acknowledgment The author thanks Frank Lehmann, Department of Prosthodontics, Propaedeutics and Dental Materials, School of Dentistry, Christian-Albrechts University at Kiel, for preparation of the scanning electron micrographs.
References 1. Blatz MB, Sadan A, Kern M. Resin-ceramic bonding: A review of the literature. J Prosthet Dent 2003;89:268–274. 2. Kern M. Resin bonding to oxide ceramics for dental restorations. J Adhes Sci Technol 2009;23:1097–1111. 3. Klosa K, Wolfart S, Lehmann F, Wenz HJ, Kern M. The effect of storage conditions, contamination modes and cleaning procedures on the resin bond strength to lithium disilicate ceramic. J Adhes Dent 2009;11:127–135. 4. Shahin R, Kern M. Effect of air-abrasion on the retention of zirconia ceramic crowns luted with different cements before and after artificial aging. Dent Mater 2010;26:922–928. 5. Kern M, Sasse M, Wolfart S. Ten-year outcome of three-unit fixed dental prostheses made from monolithic lithium disilicate ceramic. J Am Dent Assoc 2012;143:234–240. 6. Blatz MB. Long-term clinical success of all-ceramic posterior restorations. Quintessence Int 2002;33:415–426. 7. Heintze SD, Rousson V. Survival of zirconia- and metal-supported fixed dental prostheses: A systematic review. Int J Prosthodont 2010;23:493–502. 8. Clausen JO, Abou Tara M, Kern M. Dynamic fatigue and fracture resistance of non-retentive all-ceramic full-coverage molar restorations. Influence of ceramic material and preparation design. Dent Mater 2010;26:533–538. 9. Kern M, Sasse M. Ten-year survival of anterior all-ceramic resinbonded fixed dental prostheses. J Adhes Dent 2011;13:407–410. 10. Sasse M, Kern M. CAD/CAM single retainer zirconia-ceramic resinbonded fixed dental prostheses: Clinical outcome after 5 years. Int J Computerized Dent 2013;16:109–118. 11. Gu XH, Kern M. Marginal discrepancies and leakage of all-ceramic crowns: Influence of luting agents and aging conditions. Int J Pros thodont 2003;16:109–116.
References 12. Tinschert J, Natt G, Mautsch W, Augthun M, Spiekermann H. Fracture resistance of lithium disilicate-, alumina-, and zirconia-based three-unit fixed partial dentures: A laboratory study. Int J Prosthodont 2001;14:231–238. 13. Bachhav VC, Aras MA. Zirconia-based fixed partial dentures: A clinical review. Quintessence Int 2011;42:173–182. 14. Schwartz NL, Whitsett LD, Berry TG, Stewart JL. Unserviceable crowns and fixed partial dentures: Life-span and causes for loss of serviceability. J Am Dent Assoc 1970;81:1395–1402. 15. Walton JN, Gardner FM, Agar JR. A survey of crown and fixed partial denture failures: Length of service and reasons for replacement. J Prosthet Dent 1986;56:416–421. 16. Karlsson S. Failures and length of service in fixed prosthodontics after long-term function. A longitudinal clinical study. Swed Dent J 1989;13:185–192. 17. Valderhaug J. A 15-year clinical evaluation of fixed prosthodontics. Acta Odontol Scand 1991;49:35–40. 18. Trier AC, Parker MH, Cameron SM, Brousseau JS. Evaluation of resistance form of dislodged crowns and retainers. J Prosthet Dent 1998;80:405–409. 19. Kunzelmann KH, Kern M, Pospiech P, et al. All-Ceramics at a Glance. Ettlingen: Society for Dental Ceramics, 2008. 20. Shillingburg HT, Sather DA, Wilson EL Jr, et al. Fundamentals of Fixed Prosthodontics, ed 4. Chicago: Quintessence, 2012 21. Strub JR, Kern M, Türp JC, Witkowski S, Heydecke G, Wolfart S. Curriculum Prothetik. Vol 2: Artikulatoren, Ästhetik, Werkstoffkunde, Festsitzende Prothetik. Berlin: Quintessenz, 2011. 22. Øilo G, Jørgensen KD. The influence of surface roughness on the retentive ability of two dental luting cements. J Oral Rehabil 1978; 5:377–389. 23. Pashley DH, Kalathoor S, Burnham D. The effects of calcium hydroxide on dentin permeability. J Dent Res 1986;65:417–420. 24. Kern M, Kleimeier B, Schaller HG, Strub JR. Clinical comparison of postoperative sensitivity for a glass ionomer and a zinc phosphate luting cement. J Prosthet Dent 1996;75:159–162. 25. Wolfart S, Wegner SM, Kern M. Comparison of using calcium hydroxide or a dentine primer for reducing dentinal pain following crown preparation: A randomized clinical trial with an observation time up to 30 months. J Oral Rehabil 2004;31:344–350. 26. Schüpbach P, Lutz F, Finger WJ. Closing of dentinal tubules by Gluma desensitizer. Eur J Oral Sci 1997;105:414–421. 27. Wolfart S, Linnemann J, Kern M. Crown retention with use of different sealing systems on prepared dentine. J Oral Rehabil 2003;30: 1053–1061. 28. Johnson GH, Hazelton LR, Bales DJ, Lepe X. The effect of a resinbased sealer on crown retention for three types of cement. J Prosthet Dent 2004;91:428–435. 29. Kosmac T, Oblak C, Jevnikar P, Funduk N, Marion L. The effect of surface grinding and sandblasting on flexural strength and reliability of Y-TZP zirconia ceramic. Dent Mater 1999;15:426–433. 30. Kosmac T, Oblak C, Jevnikar P, Funduk N, Marion L. Strength and reliability of surface treated Y-TZP dental ceramics. J Biomed Mater Res 2000;53:304–313. 31. Guazzato M, Quach L, Albakry M, Swain MV. Influence of surface and heat treatments on the flexural strength of Y-TZP dental ceramic. J Dent 2005;33:9–18. 32. Oblak C, Jevnikar P, Kosmac T, Funduk N, Marion L. Fracture resistance and reliability of new zirconia posts. J Prosthet Dent 2004;91: 342–348. 33. Guazzato M, Albakry M, Quach L, Swain MV. Influence of grinding, sandblasting, polishing and heat treatment on the flexural strength of a glass-infiltrated alumina-reinforced dental ceramic. Biomaterials 2004;25:2153–2160. 34. Zhang Y, Lawn BR, Rekow ED, Thompson VP. Effect of sandblasting on the long-term performance of dental ceramics. J Biomed Mater Res B Appl Biomater 2004;71:381–386. 35. Zhang Y, Lawn BR, Malament KA, Thompson VP, Rekow ED. Damage accumulation and fatigue life of particle-abraded ceramics. Int J Prosthodont 2006;19:442–448.
36. Ban S, Sato H, Suehiro Y, Nakanishi H, Nawa M. Effect of sandblasting and heat treatment on biaxial flexure strength of the zirconia/ alumina nanocomposite. Key Eng Mater 2007;353:330–332. 37. Kern M, Swift EJ Jr. Bonding to zirconia. J Esthet Restor Dent 2011; 23:71–72. 38. Friederich R, Kern M. Resin bond strength to densely sintered alumina ceramic. Int J Prosthodont 2002;15:333–338. 39. Hummel M, Kern M. Durability of the resin bond strength to the alumina ceramic Procera. Dent Mater 2004;20:498–508. 40. Wolfart M, Lehmann F, Wolfart S, Kern M. Durability of the resin bond strength to zirconia ceramic after using different surface conditioning methods. Dent Mater 2007;23:45–50. 41. Özcan M, Kerkdijk S, Valandro LF. Comparison of resin cement adhesion to Y-TZP ceramic following manufacturers’ instructions of the cements only. Clin Oral Investig 2008;12:279–282. 42. Kern M, Barloi A, Yang B. Surface conditioning influences zirconia ceramic bonding. J Dent Res 2009;88:817–822. 43. Yang B, Barloi A, Kern M. Influence of air-abrasion on zirconia ceramic bonding using an adhesive composite resin. Dent Mater 2010;26:44–50. 44. Nicholls JI. Tensile bond of resin cements to porcelain veneers. J Prosthet Dent 1988;60:443–447. 45. Quaas AC, Yang B, Kern M. Panavia F 2.0 bonding to contaminated zirconia ceramic after different cleaning procedures. Dent Mater 2007;23:506–512. 46. Yang B, Wolfart S, Scharnberg M, Ludwig K, Adelung R, Kern M. Influence of contamination on zirconia ceramic bonding. J Dent Res 2007;86:749–753. 47. Kern M, Thompson VP. Eine einfache Versuchsanordnung zur universellen Prüfung des Klebeverbundes im axialen Zugtest. Dtsch Zahnärztl Z 1993;48:769–772. 48. Blatz MB, Sadan A, Kern M. Bonding to silica based ceramics: Clinical and laboratory guidelines. Quintessence Dent Technol 2002; 25:54–62. 49. Pisani-Proenca J, Erhardt MC, Valandro LF, et al. Influence of ceramic surface conditioning and resin cements on microtensile bond strength to a glass ceramic. J Prosthet Dent 2006;96:412–417. 50. Azimian F, Klosa K, Kern M. Evaluation of a new universal primer for ceramics and alloys. J Adhes Dent 2012;14:275–282. 51. Awliya W, Odén A, Yaman P, Dennison JB, Razzoog ME. Shear bond strength of a resin cement to densely sintered high-purity alumina with various surface conditions. Acta Odontol Scand 1998; 56:9–13. 52. Kim BK, Bae HE, Shim JS, Lee KW. The influence of ceramic surface treatments on the tensile bond strength of composite resin to allceramic coping materials. J Prosthet Dent 2005;94:357–362. 53. Kern M, Thompson VP. Bonding to a glass infiltrated alumina ceramic: Adhesive methods and their durability. J Prosthet Dent 1995;73:240–249. 54. Kern M, Wegner SM. Bonding to zirconia ceramic: Adhesion methods and their durability. Dent Mater 1998;14:64–71. 55. Derand T, Molin M, Kvam K. Bond strength of composite luting cement to zirconia ceramic surfaces. Dent Mater 2005;21:1158–1162. 56. Tsuo Y, Yoshida K, Atsuta M. Effects of alumina-blasting and adhesive primers on bonding between resin luting agent and zirconia ceramics. Dent Mater J 2006;25:669–674. 57. Kern M, Thompson VP. Sandblasting and silica coating of a glassinfiltrated alumina ceramic: Volume loss, morphology, and changes in the surface composition. J Prosthet Dent 1994;71:453–461. 58. Özcan M, Vallittu PK. Effect of surface conditioning methods on the bond strength of luting cement to ceramics. Dent Mater 2003; 19:725–731. 59. Blatz MB, Chiche G, Holst S, Sadan A. Influence of surface treatment and simulated aging on bond strengths of luting agents to zirconia. Quintessence Int 2007;38:745–753. 60. Wada T. Development of a new adhesive material and its properties. In: Gettleman L, Vrijhoef MMA, Uchiyama Y (eds). Proceedings of the International Symposium on Adhesive Prosthodontics, 1986 June 24. Amsterdam, Netherlands. Chicago: Academy of Dental Materials, 1986:9–18.
185
9
Cementation Procedures for Ceramics 61. Piwowarczyk A, Lauer HC, Sorensen JA. The shear bond strength between luting cements and zirconia ceramics after two pretreatments. Oper Dent 2005;30:382–388. 62. de Souza GM, Silva NR, Paulilo LA, De Goes MF, Rekow ED, Thompson VP. Bond strength to high-crystalline content zirconia after different surface treatments. J Biomed Mater Res Part B Appl Biomater 2010;93:318–323. 63. Lüthy H, Loeffel O, Hämmerle CH. Effect of thermocycling on bond strength of luting cements to zirconia ceramic. Dent Mater 2006; 22:195–200. 64. Lehmann F, Kern M. Tensile bond strength of RelyX Unicem to ceramics [abstract 0829]. J Dent Res 2007;86. 65. Abou Tara M, Eschbach S, Wolfart S, Kern M. Zirconia ceramic inlay-retained fixed dental prostheses—First clinical results with a new design. J Dent 2011;39:208–211. 66. Kern M. Controlled airborne-particle abrasion of zirconia ceramic restorations. J Prosthet Dent 2010;103:127–128. 67. Frankenberger R, Lohbauer U, Tay FR, Taschner M, Nikolaenko SA. The effect of different air-polishing powders on dentin bonding. J Adhes Dent 2007;9:381–389. 68. Kumbuloglu O, Lassila LV, User A, Vallittu PK. A study of the physical and chemical properties of four resin composite luting cements. Int J Prosthodont 2004;17:357–363. 69. Attia A, Kern M. Effect of cleaning methods after reduced-pressure air abrasion on bonding to zirconia ceramic. J Adhes Dent 2011; 13:561–567. 70. Kiyan VH, Saraceni CH, da Silveira BL, Aranha AC, Eduardo Cda P. The influence of internal surface treatments on tensile bond strength for two ceramic systems. Oper Dent 2007;32:457–465. 71. Brum R, Mazur R, Almeida J, Borges G, Caldas D. The influence of surface standardization of lithium disilicate glass ceramic on bond strength to a dual resin cement. Oper Dent 2011;36:478–485. 72. Cömlekoglu ME, Dündar M, Güngör MA, Sen BH, Artunç C. Preliminary evaluation of titanium tetrafluoride as an alternative ceramic etchant to hydrofluoric acid. J Adhes Dent 2009;11:447–453.
186
73. Klosa K, Boesch I, Kern M. Long-term bond of glass ceramic and resin cement: Evaluation of titanium tetrafluoride as an alternative etching agent for lithium disilicate ceramics. J Adhes Dent 2013; 15:377–383. 74. Zhang S, Kocjan A, Lehmann F, Kosmac T, Kern M. Influence of contamination on resin bond strength to nano-structured aluminacoated zirconia ceramic. Eur J Oral Sci 2010;118:396–403. 75. Jevnikar P, Krnel K, Kocjan A, Funduk N, Kosmac T. The effect of nano-structured alumina coating on resin-bond strength to zirconia ceramics. Dent Mater 2010;26:688–696. 76. Aboushelib MN, Kleverlaan CJ, Feilzer AJ. Selective infiltrationetching technique for a strong and durable bond of resin cements to zirconia-based materials. J Prosthet Dent 2007;98:379–388. 77. Aboushelib MN, Mirmohamadi H, Matinlinna JP, Kukk E, Ounsi HF, Salameh Z. Innovations in bonding to zirconia-based materials. 2. Focusing on chemical interactions. Dent Mater 2009;25:989–993. 78. Aboushelib MN, Matinlinna JP, Salameh Z, Ounsi H. Innovations in bonding to zirconia-based materials. 1. Dent Mater 2008;24:1268– 1272. 79. Phark JH, Duarte S Jr, Blatz M, Sadan A. An in vitro evaluation of the long-term resin bond to a new densely sintered high-purity zirconium-oxide ceramic surface. J Prosthet Dent 2009;101:29–38. 80. Casucci A, Monticelli F, Goracci C, et al. Effect of surface pretreatments on the zirconia ceramic-resin cement microtensile bond strength. Dent Mater 2011;27:1024–1030. 81. Yang B, Scharnberg M, Wolfart S, et al. Influence of contamination on bonding to zirconia ceramic. J Biomed Mater Res B Appl Biomater 2007;81:283–290. 82. Yang B, Lange-Jansen HC, Scharnberg M, et al. Influence of saliva contamination on zirconia ceramic bonding. Dent Mater 2008;24: 508–513. 83. Bock T, Meier F, Salz U. Non-abrasive decontamination method for saliva-contaminated ceramics [abstract 1327]. J Dent Res 2010;89.