Friday, May 10, 2013
These come into your practice all the time…the kid who falls and chips her front tooth, the teenager who was horsing around with his friends or the parent whose child bumped her in the mouth.
These patients all need an immediate restoration that you sometimes only have 30-45 minutes to provide (Figs 1-4 at left).
Are you able to deliver a quick restoration that is also esthetically acceptable?
Direct composite used to restore a class IV fracture may be a temporary restoration until a crown can be placed, but in my practice I always try to make it the definitive restoration unless too much tooth structure is lost for long term predictability.
But whether your composite is a temporary or permanent fix, the goal always should be to create something you and the patient can be proud of. The best feeling is seeing the patient happily showing their previously broken tooth to the neighbor who drove them to your office for the emergency. You never want that patient to leave saying, “Well, it looks bad, but it is only a temporary and my dentist only had 30 minutes to do it.”
So where do we start? Going back to my discussion on color and shade selection and form and function from my article on using composite for diastema cases, let’s start with a mock-up.
You only have 30 minutes to see this patient in your office. You numb them up and while they are numbing up you quickly do a shade evaluation and a mock-up. I only do 1-2 shades for most patients with these Class IV fractures. If they need more than that, I will bring them back in for another appointment.
Next check the occlusion and make any adjustments. Now take a template of that mock-up and be sure to have it cover the palate for support and definitive seat. Then trim it to the facial-incisal line angle so you know exactly where the incisal edge position needs to be esthetically and functionally. Now use a fine diamond bur to smooth sharp edges and make a 45 degree bevel that is about 2 mm in length on the facial margin and then feather it to a smooth finish line. This is extremely important in order to blend the composite and allow a seamless facial finish.
Fig. 5: It is helpful to have the template cover the palate for a definitive seat.
Fig. 6: The fracture line is scored with a sharp instrument to provide a guideline.
Place the template back in the mouth and use a sharp instrument such as scaler or explorer to mark the template to indicate where the fracture is located (Figs. 5, 6). Now use fine pumice over the whole tooth to clean.
Fig. 7: Tapetrix works well to protect the adjacent teeth while etching/bonding. Plumbers’ tape works just as well.
This all takes no more than 5-10 minutes. Once you are familiar with this technique it will take no time. In my office I can do all the preliminary work in 5 minutes, and now I am ready to actually do the direct composite.
I apply Tapetrix to adjacent teeth to protect them from the etchant (Fig. 7). I then go through my whole bonding protocol and now I am ready to place my first layer. It is important to remember that we build the tooth from the lingual layer and slowly add the layers until we complete the facial layer. If I am only doing 2 shades, then I will do it just like the natural layering of a tooth with enamel on the outside and dentin on the inside.
Fig. 8: The first enamel layer is added to the template. Note: It should be thin enough to see the color of the template underneath. You may want to use some modeling resin with a brush to thin it.
The first layer will be the enamel shade composite. Place it on the template a little past the fracture line that you scored and seat the template on the tooth (Fig. 8). Now carefully tuck the composite lingualy to adapt to the tooth and cure this increment. It should be thin and transparent enough to see the color of the template underneath (Figs. 9, 10). Now add the dentin layer while being sure to keep the template in place to support the enamel layer because it is so thin. Be sure to bring the dentin layer slightly over the bevel you created but still allow enough room for that final enamel layer. You should be able to see no show through of the fracture at this point (Fig. 11). If you still see show through then your dentin layer is not thick enough and you may need to add more.
Fig. 9: The template with composite is seated onto the tooth.
Fig. 10: A spoon instrument is used to adapt the composite.
Fig. 11: The dentin layer is added while keeping the template in place to support the thin enamel layer. Keep the dentin striations variable in length and depth to create a natural effect.
It is important to periodically check from the incisal view to assess the thickness of each layer.
The tendency is to add too much composite, so place it sparingly. You can always add more, but if you add too much, it is more difficult and time consuming to remove the excess.
Now you are ready to add the final enamel layer.
Next is contouring, and this is one of the most important steps. Even with the best shade selection and layering, a tooth will not look like a tooth if the contours are not correctly realized.
Fig. 12: Once line angles are drawn, use a corse disk to match the line angles with the contralateral tooth.
Fig. 13: Note how the pencil lines are slightly off on tooth #9 compared with the lines on tooth #8.
Fig. 14: The final restoration showing excellent esthetics and no noticeable fracture line.
The first thing I like to do is gently smooth any little sharp pieces from the incisal edge. I then take a pencil and draw a line over the facial-incisal line angles of the tooth I am working on and the contralateral tooth. You want the line angles to match. If they do not then you may need to reduce the facial contour some more (Fig. 12). Next you draw the line angle on the facial. You want to match them to the other tooth as well (Fig.13). Once you get all the line angles correct it is like magic…the tooth becomes identical to the other tooth (Fig. 14).
I know it may seem complicated if you are unfamiliar with this technique, and it may take you a little more time the first few times you try it. But once you are comfortable, the steps become second nature and you can produce an incredible direct restoration in very little time.