Pulpotomy

The pulpotomy is the amputation of the coronal portion of the diseased pulp, preserving the vitality and function of the remaining radicular pulp. 

How do we practice Pulpotomy? What we do at school is this: They give us a plastic phantom where you can remove every teeth. If we want to the first temporary molar we just need to add wax so when we open we will find the "pulp", the wax pulp in this case.

Preparation:

1. Anesthesia and isolation. Like always we have to isolate the teeth and open the pulp chamber. Do not forget the floss!
2. Open the cavity and remove all the decayed dentine. If we remove all the decay before to expose the pulp it reduces the bacterial contamination.
3. Remove the roof of the pulp chamber. It shouldn't be outstanding of dentine on the pulp roof or pulp horns.

1. Control the bleeding with cotton balls with physiologic serum. The bleeding must yield in 5 minutes and be bright red.
2. Fixing the root pulp lightly dampened with formocresol in a cotton, and finally pressing with another dry cotton 5 more minutes.
3. If we explore the mummified pulp: black, without haemorrhage.
4. The bottom of the cavity filling with IRM, Intermediate Restorative Material (zinc oxide with eugenol). Adapt the IRM to the ground of the cavity and the severed areas attacking with cotton balls dipped in zinc oxide.
5. Final sealing of the tooth.
1. Anterior teeth: IRM + glass ionomer layer and finally reconstruction of the restoration.
2. Posterior teeth: metal crown that prevents leaks, fractures and secondary decays.       

  

IRM: Intermediate Restorative Material PREPARATION:

Temporary crown

How to make a temporary crown? What we need to do before the milling is what we call the silicone key. What we can see on the next picture is the negative of our preparation. There is two molars that are already milled for the last practice. This time we are going to do two premolars.  

After this key we are ready to do the milling. The mechanical requirements are: retention (vertical forces) and stability with horizontal or oblique forces. Retention involves parallel walls with at least 3 grades.

• Parallelism
• Conicity
• Narrow shaft of input/output
• Height
• Surface
• Auxiliary retention 

This picture shows the best form. If we chose too conicity, like the B, the crown will easily peel off. So what we want to do is to reduce the shaft of the input/output.

Next picture shows how parallel has to be our preparation. We prefer 3º at least. If it's more there is going to increase the shaft of the input/output. Otherwise if we make inverse, the crown will impossible not go inside.  

The problem comes when is a molar very small. If we don't put a retention the crown will turn around like in the case A. So if we mark some retentions we are going to reduce the shaft of the input/output, there is going to be an unique form to put and output the crown. 

We have to keep the anatomy of the teeth but reducing the preparation. We also have to think about the marginal  adaptation and the biologic space.  

The chamfer is very important. Is the end of the preparation at the marginal level.  

The first day we put our teeth in the plaster and we did the milling of two molars. 

The second day we did the key and the milling of two premolars. 

After this we put the material of the crown inside the silicone key and we introduce the milling. We have to wait 1 minute.   

Finally what we have to do is to polish the crowns and cementing in our preparation.