A sad reply. Since my original post in Mar 18, I have been tutoring in the clinic of my state university. The academic staff have also noticed a greater tendency to prefer of students towards composites , despite the generally better physical properties of amalgam, plus the secondary technique skills that the students learn. The clinical staff have to make the students think about their choices and guide them appropriately.
- I wouldn't say that composite is naturally more conservative of tooth structure where there is decay. After the caries is removed, there are nearly always natural undercuts produced.
- Bonding strength? Only to enamel is it significant. I make sure the students still have sufficient resistance and retention form even with composites. I have seen quite a few of their fillings fail due to lack of these basic principles.
- Patient preference? Yes, I frequently hear this from students when I ask why their treatment plan is for composite rather than amalgam. I explain to them that THEY are the professionals with the material science knowledge, and while patient preferences are a consideration, they mustn't be swayed into faulty patient demands. If the composite fails in time, the patient will blame the dentist.
- By and large, the students want to use composite because it looks pretty to them and the patient (so it's easy to "sell"; it's easier to shape and carve than trying the same with setting amalgam; and they think they can ignore basic retention and resistance form. I certainly do a lot more composite than my early days when they were really s*** materials and the chemistry was poorly understood, but they still have significant failings. When you've been around as long as me and other "amalgam-era" dentists, you might appreciate a finer discretion in your choice of materials.