Posterior Composites: How Are You Handling the Transition?

Dear Anon: First you need to know some things.... 30 year amalgams are probable looking kind of golden by now, this is due to oxidation based on the zinc content of them, also had more tin and less copper and no doubt were done by hand that means more Hg and so more oxidation, more retarded marginal seal. Todays amalgam have up to 30% of coper, less tin and no zinc, no zinc means less retarded expantion, also in a capsule so less Hg, less oxidation, less long term marginal seal. Usually high content of coper means less creep but odly enough, less creep doesnt mean less marginal fractures. Also remember that todays amalgams are spherical particles that need less condensation pressure to get less porosity than old amalgams, that means that if you go to hard on them you get more creep and less final resistance.NO or less oxidation means no change in colour(that is how you can tell) If you are not a posterior composite restaurations kind of doctor and you are just begining the transition here are some tips. Stick to the basics. NO composite restoration bigger than a third of the clinical crown. Full acid etch or if you are using last generation of adhesives only acid etch in the enamel (they say dont but it is still needed) 30° bevel in the margins in the proximal boxes. No beveling in the occlusal margins. If anything goes over a third of the crown go with a cemented ceramic or ceromer done by a lab. No unsupported resin (dont try to close big mesio distal gaps with resin, go with lab work) Ensure marginal seal. DO and I mean DO a good isolation. In terms of post op sensitivity, you wont have to worry if you make a good first thin layer( read some Urtembrink) ensure contact spots with a good technique with contact pro or similar. I usually use a segmented matrix system like V-ring That is a New zealand system and is really great. Bet of luck

In order to be successful in transitioning from amalgam to resin you need to consider the following: -You need to retrain yourself (formal continuing education) -posterior resins are very techique sensitive -you cannot use amalgam thinking and replace just a material -resins done well take about 2-3 times longer than amalgams therefore you need to adjust your fee structure accordingly not to be frustrated

Use the opportunity when discussing RBA's (risks, benefits, alternatives) of amalgam vs composite to include gold in the discussion as the material of choice (even for occlusal lesions). Get a few of these into your own mouth if possible. Take some courses or join a gold study club. If esthetics are not a factor, there's no controversy about the best material.