Your January JADA article about amalgam bonding ("Clinical Evaluation of Amalgam Bonding in Class I and II Restorations" by David B. Mahler, Ph.D., and John H. Engle, D.D.S.) really ticks me off. Of all the bonding agents available to bond amalgam restorations, why was Panavia 21 (J. Morita USA Inc.) alone selected? It would have been the last one I would have used. Of course it sticks to instruments and distributes irregularly, since it is an oxygen-inhibited, self-curing material.
Manufacturer’s instructions advise: etch only enamel; thoroughly dry both enamel and dentin as water hinders the set; and use of pulp protective agents over thin dentin coverage. This ensures that a smear layer is left, that no resin tags form in the dentin tubules and that dentin tubules are desiccated, which virtually guarantees sensitivity.
Real-world dentists would receive better information if several light-cured agents bonding both enamel and dentin, filled and unfilled, three-step and the so-called one-step, as well as Amalgambond (Parkell), had been used in the study.
I don’t see how the authors can draw conclusions about all bonding agents using only one material that is dissimilar to nearly all the others and may not have been developed to bond to dentin as a primary use. Most enamel/dentin bonding agents, properly applied, require the dentin to be left moist in order for the bipolar primer and solvent (alcohol or acetone or both) to "chase" the water into the tubules, allowing resin-retentive "tags" to form in the tubules that unite composite, resin and dentin.
To visualize this, examine a current OptiBond Solo (Kerr) advertisement. In my experience using OptiBond 3-step, this greatly reduces post-op sensitivity.
Finally, I wonder who allowed funding of a study that wasted time and money, proved nothing, probably misinformed and very likely was a disservice to or abuse of patients?
Who peer reviewed the article and approved publication by JADA? Is it any wonder why there often exists a disconnect between private practice dentists, the ADA and especially dental school researchers?
What do you say to this?
