No!
It is neither as strong nor as durable. It is susceptible to fluid degradation. It is an entirely different situation.
Are there any recent ppr discussed that ? With developing of adhesive ?
In many of the dentine bond tests, the age old Optibond FL still comes out top, and has a max strength of 24mpa (at best), still a fraction of enamel bonding
This would be a good topic for a Medline search. The study question would be something to the effect of: when comparing dentin bonding to enamel bonding in patients receiving porcelain veneers what differences exist relative to the strength of the bond, durability of the bond and risks of micro leakage?
If you do such a search you will find literally thousands of references with the vast majority demonstrating a stronger, more durable bond to enamel with a lowered likelihood of micro leakage. Like most things in dentistry there is no one definitive source of information however there are so many articles that pushed the equation towards enamel bonding being a much more predictable outcome it would be hard to consider dentin bonding as being equivalent.
You can probably assimilate the in vitro tests in the relatively confident that the outcomes of these tests are so compelling as to not demand much from in vivo testing. Nonetheless there are sufficient numbers of in vivo tests that confirm the laboratory findings.
Dentin bonding is generally much weaker than enamel bonding (with the exception of 7th generation adhesives). A veneer bonded simultaneously to enamel and dentin will always stain and/or fail at the dentin interface first.
Agreeing with the finding that bonding to enamel is more reliable as bonding to dentin, the question can be refraised as: is it contra-indicated to place a porcelain veneer with cervical part bonded to dentin? I would think that a certain risk for imperfections such as marginal staining would be higher for those situations and should be explained to the patient, but still the veneer can be placed. Alternatives like full crowns also have their risk profiles such as pulp necrosis, fracture etc. Comparing the techniques and possibilities I think the minimal invasive option still has the most advantages.
To make it more complicated: what has a better prognosis: a veneer bonded to enamel in a high caries risk patient or a veneer bonded to dentin in a low risk patient?
These aspects are very suitable to be investigated in practice based, (retrospective) pragmatic controlled trial designs.
Often, we have no choice but to bond a veneer partially or entirely on dentin. Not ideal, but necessary.
shear bonding strength of bonding in enamel is higher than that of dentine due to wet dentinal tubule even using self etch bonding with acetone as a chelating agent. so that it is more preferable to prepare in enamel portion of tooth structure, and updating is for thiner and thiner veneers with minimum of preparation may reach to 0.2mm. All these modification in preparation to get high durability bonding strength.
Bonding with adhesives from generations 1-6 is definitely weaker at the dentinal interface than at the enamel interface. 7th generation adhesives close the differential somewhat. The problem is not so much a weak bonding to dentin as it is the differential adhesion to the dentin and enamel, stressing the stiff porcelain veneer. The key would be to have an adhesive that bonds EQUALLY (even if this were at a lower adhesion) to both enamel and dentin.
never, as long as I live. Thousands of proofs in my lab over 27 years, same today.
Roland Frankenberger dear dr. in this question we are talking about the strong of bonding as a force? because if we are talking about strong as a stability of bonding, the enamel is stronger! but if we talk about this as a force there is some research from UK Leuven research group that the micro tensile of enamel bonding is less than in dentin. Those results are different in your lab?
No. But force - initial force - alone is not important, enamel is more brittle, therefore MTBS is lower sometimes. Durability is key.
Enamel bond is much stronger than dentine, the concept is to keep the veneer intraenamel for favorable outcome. max thickness should not exceed ideally beyond 0.3 to 0.5 mm.
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