How to Place a Class II Composite Filling for the ADEX Exam

Step 01

Set Up Your Matrix Correctly

For this procedure, we're working on a number 20 with an MO prep. The first thing you're going to do after placing your rubber dam is set up your sectional matrix. We use a kidney-shaped sectional matrix here, and the key thing to get right is the height. You want the occlusal edge of that matrix sitting right at the marginal ridge level of the tooth. Put your thumb on it and hold it there while you place the wedge.

Go in from the lingual with your wedge, and then check your cervical seal. You want to look inside and confirm that the matrix is completely sealing the gingival floor, the lingual wall, and the buccal wall of the prep. Nothing should be open.

If you're not getting a good seal, try a wider wedge. You can also wrap some Teflon tape around your matrix to thicken it up. Pre-wedging before placing the matrix helps shape the wedge to the natural contour of the tooth and separates the teeth slightly so you don't accidentally nick the adjacent tooth.

Once your Garrison ring is in place, check that the notch on the underside is straddling your wedge, that the matrix top is level with the marginal ridge, and that you have a tight seal all the way around. Then take a burnishing instrument and push the contact area in so you have nice approximation with the adjacent tooth.

Step 02

Apply Your Adhesive

On the typodont, you don't need to etch. Go straight to your bonding agent. Apply it and make sure you're coating all of the walls of the prep. Then either air-dry it lightly or blot out the excess. You don't want pooling of bond in there, but you also don't want to miss any walls.

Step 03

Fill in Two Stages

For the fill, I like to start with a flowable composite to line the walls and floor of the prep. You don't have to do this — you can go straight to packable — but the flowable helps you get into those tight corners and ensures you don't have any gaps, especially at the cervical margin. Use an explorer or a perio probe to make sure it flows everywhere it needs to go and that you don't have any bubbles.

Then go in with your packable composite. Start by building your proximal wall first. Use a small plugger and pack toward the adjacent tooth to create your marginal ridge. Before you cure, check the occlusal embrasure. You want that marginal ridge rolling in a way that mirrors the anatomy of the adjacent tooth — look for symmetry.

At this point, remove the Garrison ring and take a good look at your proximal wall before you fill the rest of the tooth. If you don't like what you see, stop and redo it. Check that the composite is fully sealing the cavity, there are no open margins, and that the emergence from the cervical is smooth and natural looking.

Step 04

Build the Occlusal Anatomy

Now you've essentially turned your Class II into a Class I. Fill in the occlusal surface and think about anatomy as you go. You're trying to create a natural fossa in the center and bring the composite up toward the cusps in a way that follows the angulation of the adjacent teeth. Hold your instrument so part of it rests on the natural tooth and part of it is on the filling — that way you're following the tooth's own contours.

Pack it down well so you don't have any voids inside. If you're not sure whether you have enough composite, leave a little excess. You can always reduce it later. Just don't leave a deficiency.

Step 05

Remove Flash and Check Your Contact

Once you've cured, check your contact first with floss. It should feel snug and smooth. If you're getting fraying, you have flash to clean up.

Use a GK14L gold foil instrument to run along the interproximal surface and remove any flash you see. Be careful not to dig into the filling — you're just running along the surface. Then use an interproximal strip to smooth the area beneath the contact. Use a narrow strip so you're not cutting into the gingiva, and make sure the non-cutting section is positioned right at the contact point so you don't remove your contact while polishing. Once that's done, recheck with floss to confirm your contact is still tight.

Step 06

Adjust the Occlusion

Before you close the patient down and check occlusion with articulating paper, look at your marginal ridge and compare it to the adjacent tooth. If it's significantly taller, reduce it first. If you put heavy pressure on a filling that's way out of occlusion, you can actually break pieces off.

When you do check with articulating paper, look for contacts that are heavier or taller than the surrounding teeth.

In most typodont scenarios, you're trying to keep contacts on cusp tips and away from marginal ridges and cusp inclines.

Step 07

Polish and Final Check

Bonding agent can leave a thin layer over the whole tooth, so polish the entire surface — not just the filling. Use a composite polishing bur on slow speed, and use a needle finishing bur to refine any anatomy before you go to the polisher.

When you're done, take a good look at everything before you hand it in. Run your explorer around the margins and make sure there are no gaps, no flash, and no deficiencies anywhere, including at the cervical. Check that your marginal ridge mirrors the anatomy of the adjacent tooth. Recheck your contact one more time. And confirm that your occlusion looks clean and balanced.