**24. Cementation**

It is important that the luting agent should fill all the dead space within the root canal system. a rotary paste filler or cement tube is used to fill the canal.post and core is inserted gently to reduce hydrostatic pressure which could cause root fracture.

It is recommended that a groove placed along the side of the post to allow excess cement to escape, if a parallel sided post is being used.

### **25. Cements and disadvantages**


#### **26. Removal of existing posts**

Occasionally a failed post and core must be removed, then if sufficient post length is exposed coronally, it can be retrieved with thin beaked forceps.

Vibrating the post with a ultrasonic scaler will weaken the cement and facilitates easy removal. Here a thin scaler tip is recommended or alternatively a post puller is used. [post puller cannot be used for fractured post.]

Fractured posts should be drilled out but care should be taken not to deviate from the canal. This is best limited to short fractured posts

#### **27. Masserann 1966 handling**

He used a hallow end cutting tubes o r trephines to prepare a thin trench around the post. Post retrieved can be facilitated by using an adhesive to attach a hallow tube extractor or by using a threaded extractor.

Newer Concepts:

Zarow, M proposed new classification was to help the clinician to select the most appropriate treatment plan for restoring root filled teeth when choosing between a

composite core alone, a composite core reinforced by fiber post, a gold cast post or implant treatment. **The following is the classification:-** [74]


The three categories given by Motasum Abu-Awwad in 2019 are [75].

