The tooth has been endodontically treated and filled with gutta-percha. The remaining tooth structure must be prepared according to conventional principles.

1. Selection of Post Size. Posts are available in three different sizes to accommodate a variety of teeth. The number of rings at the coronal end of the posts indicate size.

A. Size and direction of canal is determined by radiographic examination.
B. A general rule can be followed for post size selection:
• Post No. 1 - Central and lateral maxillary incisors Buccal canals of maxillary molars Multi-rooted teeth Mesio-buccal and lingual canals of mandibular molars
  
• Post No. 2 - Central and lateral maxillary incisors Distal canals of mandibular molars Palatal canals of maxillary molars
  
• Post No. 3 - Maxillary and mandibular canine Palatal canals of maxillary molars Large/wide canals
  

2. Canal Preparation. A. General rules should be followed for length of root canal preparation: Post length should equal the length of the crown. The post should be 2/3 to 3/4 the length of the root. A minimum of 3-5 mm of gutta-percha should remain at the apex. Proper isolation must be used.

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B. Remove gutta-percha with a #1 or #2 Peeso Reamer, #3 Gates Glidden, or a heated endodontic plugger.



C. Select the Pre-Shaping (end-cutting) and Finishing (side-cutting) drills which correspond to the selected post size. D. Shaping the Canal: (1) Use the Pre-Shaping drill to complete the preliminary preparation. This instrument determines the final depth to which the post will be placed. It also serves to guide the final canal preparation which will increase internal diameter by 0.5 mm.

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(2) A rubber stopper or the 2 rings (a) on the shaft of the drill can be used as a guide for the length of preparation with radiographic verification. The 2 rings on the shaft are at a distance of 7.5 mm and 8.5 mm away from the tip of the drill.
(3) Assure the drill is always positioned in gutta-percha.
(4) Remove debris from canal with a water spray, followed by air drying.

E. Finishing the Canal: (1) The final preparation is made using the Finishing drill. The Finishing drill must penetrate completely to the depth established by the Pre-Shaping drill.

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(2) The form of this instrument will create the housing for the post in a single motion. The final canal preparation allows sufficient space for the post and 30 microns for bonding material. This is a side-cutting, not an end-cutting, instrument.

4. Post Cementation.

A. Post Space Preparation:

(1) Apply UNI-ETCH®* (32% H3PO4) for 15 seconds and rinse with water.
(2) Blot the canal dry with a large paper point, leaving the dentin visibly moist.
(3) Apply 2 coats of ALL-BOND® 2* Primers A and B or ONE-STEP®*. Refer to manufacturer's instructions. Not all one-bottle adhesives bond to dual-cured or self-cured composites.
(4) Blot the canal dry with a paper point. Repeat with a new paper point until the paper point returns dry from the canal. This step is important for removal of any pooled primers so that there is no interference in complete seating of the post.
(5) Light-Cure ONE-STEP for 10 seconds with a small light tip. Light access is crucial.

NOTE: The user must use their own discretion as to whether light will reach into the canal space. Although ONE-STEP is very light sensitive, Bisco cannot guarantee success if the appropriate amount of light has not reached the adhesive.

B. Post** Cementation:

(1) Coat the post with ALL-BOND 2 Primers A and B or with ONE-STEP and lightly air dry. Light cure for 10 seconds.
(2) Mix equal amounts of POST CEMENT HI-X™* base and catalyst into a uniform paste (10-15 seconds).
(3) Fill a CENTRIX AccuDose®* NeedleTubes™* syringe tip with the cement and inject the cement into the canal. Start at the apical end of the canal and withdraw the tip towards the pulp chamber. (As an alternative, a lentulo spiral or paste filler may be used to carry the cement into the canal.)
(4) Seat the post into the canal gently and maintain firm pressure (for 5-10 seconds) once the post is seated.
(5) As soon as the cement has set, proceed with the core build-up.

Post Cement HI-X left on the mixing pad may appear not to set. This is due to oxygen inhibition of the polymerization process. The cement will polymerize (set) in a normal fashion. The user can confirm this by placing a mylar strip over the excess cement on the pad; the cement will set within the setting time specified in the Post Cement Hi-X Directions for Use.

Since Post Cement HI-X sets very hard, removal of excess cement should begin as soon as the post is seated. Failure to remove the cement early may result in the cement adhering to areas from which it should be removed.

The use of Pre-Bond is not necessary for the cementation using Post Cement HI-X.

5. Final Preparation.
Conventional principles of tooth preparation must be followed for optimal results.

• Preparation for final restoration must end on sound tooth structure.
• There must be 1.5 mm of sound tooth structure beyond the core material.
• Positive horizontal and vertical walls should exist.

6. Post Removal.
A FIBER POST REMOVAL KIT is available through Bisco. See FIBER POST REMOVAL TECHNIQUE description and instructions available with the FIBER POST REMOVAL KIT.