Correspondence between fiber post and drill dimensions for post canal preparation

Area of Science:

• Dental Materials Science
• Endodontics
• Biomaterials Engineering

Background:

• Fiber posts are widely used in endodontic restorations.
• Accurate sizing of posts and preparation drills is crucial for successful cementation.
• Discrepancies can impact the integrity of the final restoration.

Purpose of the Study:

• To compare the dimensional accuracy between fiber posts and their corresponding root canal preparation drills.
• To evaluate the spatial correspondence of different post systems and drill calibers.

Main Methods:

• Three major endodontic post brands (Exacto, ParaPost Taper Lux, Macro-Lock Illusion X-RO) and their drills were analyzed.
• Scanning electron microscopy (SEM) was used to microphotograph posts and drills.
• ImageJ software analyzed post and drill diameters at the apical extreme (Pd0, Dd0) and 5mm from the apex (Pd5, Dd5).
• Statistical analysis was performed using the student t-test.

Main Results:

• Exacto posts (0.5) were larger than their drills at the apical extreme (Pd0).
• ParaPost drills (4.5, 5, 5.5) were significantly larger than their corresponding posts at the apical extreme (Dd0).
• Exacto posts (0.5, 1) were larger than their drills at 5mm from the apex (Pd5), while Exacto post 2 was smaller.
• Macro-Lock drills (4) and ParaPost drills (5) were larger than their posts at 5mm from the apex (Dd5).

Conclusions:

• A notable lack of spatial correspondence exists between many fiber posts and their associated preparation drills.
• This dimensional mismatch can lead to suboptimal luting cement film thickness.
• Compromised cement thickness can diminish bond strength and potentially induce critical stresses within the restoration.