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Can we please go back to working with wax? This semester we have been working with the handpieces almost every other day. We have been learning about ideal outline form and then trying to produce the ideal outline form in our fake ivorine (plastic) teeth. In my personal experiance this is tremendously difficult and requires quite a bit of practice, patience, and many trips to the Henry-Schein store upstairs to buy more teeth. When you mess up a tooth the instructor tells you to go buy a new tooth and start over…I have worn a cattle trail through the halls as I make the long walk upstairs to get more teeth

It is difficult because of the precision required to prepare a tooth to ideal standards. Let me explain what ideal outline form means. A tooth is very intricately put together. It is composed of enamel and dentin amongst other tissues and they support each other in a very specific way. You simply cannot take your drill, make a hole in a tooth, fill it and let the patient leave. In dental school we are taught the ideal outline form which is to say, the proper outline you must drill into a tooth to keep it structurally viable. By drilling around cusps and grooves properly you maintain proper support of the tooth and will hopefully ensure its use in the mouth for years to come.

We are taught ideal outline form, so when we enter the clinic we can understand how to support the tooth we have just prepped (which most likely does not follow ideal outline form) and make it last for as long as possible.

Ideal outline form also ensures the retention of the restorative material we place in the mouth. Ideal outline form requires specific depth, angles, grooves, boxes, dovetails, convergence and divergence of specific walls, etc. to make sure the amalgam or composite will remain in the tooth after 10,000,000 chewing cycles. The average person will chew 1,000,000 times a year. After this number of cycles you want to make sure that your restoration will last. You know you have failed if your patient comes back the next day with a hole in their tooth.

So you can understand how difficult it can be to pick up a handpiece spinning at 100,000 rpm and make a 1.5 mm drop into a tooth, follow proper outline, converging the walls, etc. with out making a mistake. It can be frustrating, but it is fun and you do get better everyday. Enough talk, here are some of the things we have been working on recently.

After prepping our teeth, we get to fill them. We place a rubberdam for every procedure along with a toffelmire and a matrix band. The toffelmire is the long silver thing holding the silver band around the tooth. Yes we are quizzed on the toffelmires intricacies as well. For example there are two screws on the toffelmire and you need to know which direction each one turns (one goes clockwise, the other goes counter-clockwise).

Here are some pics, enjoy!

The first tooth is #31 MO (Mesial Occlusal) after it has been burnished. The other tooth in the toffelmire is #29, a second premolar which is prepped for a MOD (Mesial Occlusal Distal). It is ready to go.