Monobond Etch & Prime is a self-etching single-component glass-ceramic primer that produces a similar adhesive bond strength as the conventional procedure with hydrofluoric acid and silane. The innovative new material from Ivoclar Vivadent eliminates the need for using hydrofluoric acid as the etchant and the concomitant separate working steps. Monobond Etch & Prime therefore enables safe, easy and reliable conditioning of all glass-ceramic restorations in the practice.

1. NO Hydrofluoric Acid No More

2. Etching and Silanization in one easy step
Monobond Etch & Prime is a self-etching glass-ceramic primer that allows
glass-ceramic surfaces to be conditioned without using hydrofluoric acid.
Glass-ceramics form a popular group of materials in fixed prosthetics
because they offer high mechanical strength, excellent esthetics and
fabrication processes that are well established in dentistry. The popularity
of glass-ceramics is further enhanced by the fact that they involve a
highly effective cementation technique in which the ceramic contact
surfaces are etched with hydrofluoric acid (HF), conditioned with
methacrylate silane and then incorporated through co-polymerization with
a methacrylate-based luting composite. Restorations that are adhesively
placed in such a manner are firmly supported by the tooth structure. This
results in a considerable increase in the creative leeway to design
restorations. [1, 2]
Monobond Etch & Prime

3. Glass-ceramics are typically etched with 5 - 9.5% hydrofluoric acid. In
the process, the amorphous glass compounds are selectively removed.
The result is a very clean, microretentive surface. The subsequent
silanization process generates a thin layer of covalently bonded
methacrylate groups that co-polymerize with the luting composite when
the restoration is seated. The two-step process of hydrofluoric acid
etching and silanization has been the subject of numerous publications
and is currently regarded as the state of the art for the conditioning of
glass-ceramics prior to adhesive cementation. [1, 2]
Monobond Etch & Prime

4. Effective though it may be, hydrofluoric acid raises safety issues in the
dental practice. These issues are related to the toxicity of hydrofluoric
acid and not, as is commonly assumed, to its etching effect. On
contact, hydrofluoric acid quickly enters the skin and mucous
membranes. In the body, it strongly interferes with the body's calcium
metabolism and causes severe burns in the underlying soft tissues and
sometimes as deep down as to the bones. [3] For this reason, attempts
to find an alternative to hydrofluoric acid have been made on several
occasions. However, none of these alternatives yielded results on a par
with hydrofluoric acid etching [4-7].
Monobond Etch & Prime

5. Introduced in early 2015, Monobond Etch & Prime (Ivoclar Vivadent
AG) is a glass-ceramic primer that offers an HF-free and therefore
considerably safer procedure to condition glass-ceramic materials. In
addition, Monobond Etch & Prime allows glass-ceramic surfaces to be
etched and silanated in one easy step - something that none of the
other commercially available ceramic primers can do. Table 1
describes the key constituents of the formulation (patent pending) and
their functions.
Monobond Etch & Prime

6. Table 1: Composition of Monobond Etch & Prime
Component Function Additional properties
Ammonium
polyfluoride
Etches glass-ceramic
surfaces
- HF-free and
consequently significantly less
toxic
- Stabilizes the silane coupling
agent in a highly reactive form
Silane coupling agent:
methacrylate silane &
silane cross-linking
agent
Forms a polymerizable
film on the ceramic
surface
- Methacrylate silane: strong and
durable bonding effect
- Cross-linking agent: accelerates
the reaction with the ceramic
surface
- Silane coupling agent is stable in
storage in the presence of
ammonium polyfluoride
Monobond Etch & Prime

7. Component Function Additional properties
Solvent: alcohol & water Handling
- Ease of use
- Excellent film formation
- Favourable rinsing properties
due to low evaporation
tendency
Food colourant Visibility
- Clear contrast with the colour of
the ceramic material
- Water soluble and easy to rinse
off
Table 1: Composition of Monobond Etch & Prime
Monobond Etch & Prime

8. A side effect of the break-up of the Si-O-Si bonds ("etching") by
ammonium fluoride is that the Si-O-C bonds of the silane system are
converted to highly reactive Si-OH groups (silanol). On the one hand,
these silanol groups undergo spontaneous condensation and rapidly
form insoluble polysiloxane. On the other hand, they, in theory, also
lead to a highly effective functionalization of the glass-ceramic surface.
The ammonium polyfluroide contained in Monobond Etch & Prime
suppresses the condensation reaction of the silanol groups. As a
result, Monobond Etch & Prime is the only single-bottle ceramic primer
that contains highly reactive monomeric silanol on a steady level to
provide surface active compounds at all times.
Monobond Etch & Prime

9. The application procedure and mode of action of Monobond Etch &
Prime can be explained as follows:
Monobond Etch & Prime

10. 1. Monobond Etch & Prime is applied to the glass-ceramic surface
using a microbrush and then rubbed into the surface for 20 seconds. In
the process, the primer liberates the ceramic surface from adhering
saliva proteins and silicone oils.
Monobond Etch & Prime

11. 2. Monobond Etch & Prime is left on the ceramic surface for another 40
seconds without agitating it. The polyfluoride ions now react with the
exposed ceramic to produce a roughened, clean and activated surface,
onto which the adhesion-promoting silanol compounds are deposited.
Monobond Etch & Prime

12. 3. After the primer has been allowed to react, it is rinsed off from the ceramic
surface with a water spray. In the process, the water soluble ammonium
fluoride ions are removed. The formation of Si-O-Si bonds begins. The
activated ceramic surface has a high reactivity with the silanol groups
contained in Monobond Etch & Prime and this enhances the surface
functionalization.
Monobond Etch & Prime

13. The ceramic surface is dried with compressed air until moisture is no
longer visible. In the process, the silane compounds undergo final
condensation to form a robust layer containing reactive methacrylate
end groups on the ceramic surface.
Monobond Etch & Prime

14. If the ceramic conditioning method using Monobond Etch & Prime is
compared with the conventional method, as in Table 2, it can be clearly
seen how the conditioning procedure is streamlined with the new
primer. While the procedure based on Monobond Etch & Prime
involves only one material from one bottle and three treatment steps,
conventional conditioning procedures require two materials from two
bottles (HF gel, silane primer) and five steps.
Monobond Etch & Prime

15. As development tests have shown, the new primer allows a uniform
contact time to be applied to all types of ceramic materials without
posing the risk of over-etching. If hydrofluoric acid is used, however,
the contact time must be adjusted according to the concentration of the
etchant and the type of glass ceramic being conditioned. As Table 2
shows, Monobond Etch & Prime significantly shortens the treatment
time for all ceramic materials compared with the conventional
procedure. Enabling users to apply the same contact time for all
materials reduces the risk of errors.
Monobond Etch & Prime

16. Table 2: Comparison: conventional conditioning vs Monobond Etch & Prime
Monobond Etch & Prime
Conventional (HF/silane) Monobond Etch & Prime
Etching (HF)
1. Leave on (20­60
s)
Etching &
priming
1. Apply (20 s)
Monobond Etch &
Prime and
leave on (40 s)2. Rinse with water
2. Rinse with water3. Blow dry
Priming (silane)
4. Apply primer &
leave on (60 s)
3. Blow dry
5. Blow dry
2 bottles
Application time:
80 – 120 s
1 bottle
Application time:
60 s

17. The activating effect of ammonium polyfluoride on the silane coupling
agent enables Monobond Etch & Prime to establish a strong and
lasting bond with the ceramic and luting composite. The bonding effect
on different glass-ceramic materials was assessed in conjunction with
the Variolink Esthetic DC luting composite by measuring the tensile
bond strength (TBS). The resultant values were compared with those
of the conventional combination of hydrofluoric acid etching and
Monobond Plus. To test the durability of the adhesive bond, the
specimens were aged by subjecting them to 10,000 thermocycles in
water (5°C/55°C) before the tensile bond strength was determined. The
resulting tensile bond strength values are shown in the next slide.
Monobond Etch & Prime

18. Monobond Etch & Prime
Figure 1. Tensile bond strength after artificial ageing (10,000 thermocycles); Monobond Etch & Prime
vs HF/Monobond Plus (MBP) with Variolinke Esthetic DC.

19. As can be seen in Figure 1, Monobond Etch & Prime produced tensile
bond strength values comparable to those of hydrofluoric acid etching
and Monobond Plus on all ceramic surfaces. This means that users
can take advantage of the benefits outlined in Table 2 without having to
accept any compromises in the renowned quality of the Monobond
products.
Monobond Etch & Prime
Interestingly, Monobond Etch & Prime is capable of establishing a
strong adhesive bond that is resistant to thermocycling without creating
the same pronounced etching pattern as the conventional procedure.

20. As the scanning electron microscope images of IPS e.max CAD in Figure 2
show, the new primer results in a significantly less pronounced erosion pattern
than 5% hydrofluoric acid gel. This means that over-etching of the ceramic can
be reliably avoided and the ceramic does not exhibit the mat appearance
typical of ceramic surfaces etched with hydrofluoric acid.
Monobond Etch & Prime
Figure 2: SEM images of IPS e.max CAD

21. The reason why Monobond Prime & Etch achieves similar bond
strengths as the combination of hydrofluoric acid etching and
Monobond Plus even if it produces a less pronounced etching pattern
lies in the fact that the ammonium polyfluoride ions induce the
formation of reactive silanol groups. When the ceramic is rinsed, the
polyfluoride is removed and the silanol groups are no longer stabilized.
This gives way to a highly effective functionalization process that
offsets the less pronounced etching pattern.
Monobond Etch & Prime

22. Given its self-etching capabilities, Monobond Etch & Prime features
additional innovative properties that conventional glass-ceramic
primers cannot offer. Ammonium polyfluoride ensures that surface
contamination such as salivary proteins and silicone oils, which may be
present after the try-in of the ceramic restorations, are removed,
thereby eliminating the need for an additional cleaning step prior to
cementation.
Monobond Etch & Prime

23. Additionally, the issue of how to proceed with restorations that were
pre-conditioned in the lab and may, for instance, have become
subsequently contaminated no longer poses a difficulty. While a
second etching with hydrofluoric acid always incurs the risk of over-
etching and damage to the microstructure of the ceramic, this risk does
not arise with Monobond Etch & Prime. It is no problem to use
Monobond Etch & Prime to re-condition a glass-ceramic restoration
that has previously been conditioned in the laboratory either with a
conventional combination of hydrofluoric acid and silane or with the
new primer.
Monobond Etch & Prime

24. Conclusion: Monobond Etch & Prime is a self-etching single-
component glass-ceramic primer that produces a similar adhesive
bond strength as the conventional procedure with hydrofluoric acid and
silane. The innovative new material from Ivoclar Vivadent eliminates
the need for using hydrofluoric acid as the etchant and the concomitant
separate working steps. Monobond Etch & Prime therefore enables
safe, easy and reliable conditioning of all glass-ceramic restorations in
the practice.
Monobond Etch & Prime

25. Refrences
• 1. Tian, T., et al., Aspects of bonding between resin luting cements and glass ceramic materials.
Dent. Mater., 2014. 30(Copyright (C) 2015 American Chemical Society (ACS). All Rights Reserved.): p.
e147-e162.
• 2. Pisani-Proenca, J., et al., Influence of ceramic surface conditioning and resin cements on
microtensile bond strength to a glass ceramic. J. Prosthet. Dent., 2006. 96(Copyright (C) 2014 American
Chemical Society (ACS). All Rights Reserved.): p. 412-417.
• 3. Ozcan, M., A. Allahbeickaraghi, and M. Dundar, Possible hazardous effects of hydrofluoric acid
and recommendations for treatment approach: a review. Clin Oral Investig, 2012. 16(1): p. 15-23.
• 4. al Edris, A., et al., SEM evaluation of etch patterns by three etchants on three porcelains. J
Prosthet Dent, 1990. 64(6): p. 734-9.
• 5. Della, B.A., K.J. Anusavice, and J.A.A. Hood, Effect of ceramic surface treatment on tensile bond
strength to a resin cement. Int J Prosthodont, 2002. 15(Copyright (C) 2012 U.S. National Library of
Medicine.): p. 248-53.
• 6. Comlekoglu, M.E., et al., Preliminary evaluation titanium tetrafluoride as an alternative ceramic
etchant to hydrofluoric acid. J. Adhes. Dent., 2009. 11(Copyright (C) 2012 American Chemical Society
(ACS). All Rights Reserved.): p. 447-453.
• 7. Kukiattrakoon, B. and K. Thammasitboon, Optimal acidulated phosphate fluoride gel etching
time for surface treatment of feldspathic porcelain: on shear bond strength to resin composite. Eur J Dent,
2012. 6(Copyright (C) 2012 U.S. National Library of Medicine.): p. 63-9.
Monobond Etch & Prime