When it comes to restoring endodontically treated teeth, fiber posts are an excellent solution—especially in cases where there is insufficient tooth structure to retain the final coronal restoration. In this guide, we’ll walk you through fiber post preparation and cementation from A to Z, covering essential clinical tips and steps to achieve long-lasting and predictable results.
When Do We Need a Fiber Post?
Not every tooth requires a post, and not every severely damaged tooth is an automatic candidate. A fiber post is recommended when there is insufficient retention for the final coronal seal. In multi-rooted teeth, the post is usually placed in the canal adjacent to the most destructed wall—preferably in the straighter canal rather than the largest one.
Step 1: Isolation
Before starting post space preparation, proper isolation is crucial. Remove any flowable composite or temporary material placed over the canal orifices.
Step 2: Post Space Preparation
Key Steps:
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Initial Access: Start by inserting a probe into the center of the gutta-percha (GP) to create a guide point for entry.
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Gates-Glidden Drills: Use Gates-Glidden drills to remove GP up to the desired length. Ideally, prepare two-thirds of the canal while preserving 5–7 mm of apical GP for the seal.
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Reamers: After using Gates sizes 2 and 3, switch to reamers (also size 2 and 3) to enlarge the post space. Avoid size 1 as it is fragile and prone to breakage.
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Irrigation: Perform frequent irrigation with NaOCl (preferred) or saline during preparation.
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Post Fitting: Test-fit the post frequently until it reaches the planned depth. The post should have adequate retention but should not be overly tight or loose.
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Radiographic Check: Take an X-ray before cementation to ensure proper depth, alignment, and GP removal, with at least 5–7 mm of apical GP remaining.
Step 3: Tooth Surface Treatment
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Etching: Apply 37% phosphoric acid inside the canal and on the tooth surface for about 15 seconds.
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Rinse and Dry: Rinse thoroughly using water or an irrigation needle, and dry gently.
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Bonding: Apply a dual-cure adhesive bonding system to the entire preparation.
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Remove Excess Bond: Use a paper point to remove excess bond from inside the canal to prevent interference with post placement.
Step 4: Post Surface Treatment
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Cleaning: Clean the post thoroughly with alcohol.
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Silane Application: Apply silane coupling agent for about one minute, then gently air-dry to remove any excess.
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Bonding: Apply adhesive bonding to the post and remove excess to ensure proper seating.
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Light Curing: Cure the bonding layer as recommended, ensuring the post still fits to its full length.
Step 5: Cementation and Core Build-Up
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Cement Application: Using the tip of dual-cure resin cement, inject cement directly into the canal to ensure full coverage.
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Post Placement: Insert the post, remove any excess cement, and light-cure for about 20 seconds.
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Core Build-Up: Build up the core using a reliable dual-cure core material (e.g., Charm Core).
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Finishing: Trim the post and shape the core as needed. Your tooth is now ready for the final restoration.
Clinical Tips for high Success rate
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Always place the fiber post in the straighter canal for better alignment and stress distribution.
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Avoid over-preparing the canal, which may weaken the root structure.
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Ensure thorough cleaning and bonding of both the tooth and the post to achieve maximum retention.
Following this step-by-step protocol for fiber post preparation and cementation ensures durability and optimal retention of your final restoration. The combination of proper isolation, careful canal preparation, correct bonding technique, and reliable cementation is the key to long-term clinical success.