We appreciate Dr. Williams’ letter in which he shared his experience on amalgam bonding with us. In response, we should start by pointing out that the reason for conducting this study was our concern that dentists were using amalgam bonding for all amalgam restorations, and we wondered if bonding had any merit specifically for traditional Class I and Class II amalgam restorations.
The term "traditional preparations" was intended to include intercoronal restorations of different widths (see the table on page 44 of January JADA). Although most would be considered conservative-to-moderate in size, some large and deep restorations were included. However, their numbers were not considered sufficient either to refute or confirm Dr. Williams’ improved success with the use of bonding agents for the treatment of "deep restorations."
The use of bonding vs. the use of calcium-hydroxide materials or the use of bonding amalgams in unretentive inlay-type preparations as proposed by Dr. Williams were not evaluated in this study. Therefore, to respond to the efficacy of these alternative procedures would be speculation on our part.
Our experience using both published and anecdotal information made us aware of the sensitivity factors that affect microleakage and postoperative sensitivity. We have shown from previous studies that the factors of amalgam selection, mixing ratios and condensation techniques play a significant role in the development of sensitivity; and while certain bonding agents and techniques may compensate when these factors have not been properly addressed, it was not our goal to evaluate the interaction.
Once again, we wondered if bonding had any merit for traditional Class I and Class II amalgam restorations. The results of our study could not demonstrate merit for this application. We could turn Dr. Williams’ analogy around by saying that if we were dealing only with 10-m.p.h. collisions (traditional Class I and Class II restorations), then why are air bags (bonding agents) necessary?
