Removal of a 2.0mm Post

The 2.0mm Bicon abutment post has been used clinically since 1985. The fracture rate for restorations using the 2.0mm post is less than 0.15%. Usually when an abutment post fractures, there are identifiable factors of occlusion which contributed to the metal fatigue. The appropriate placement of an implant and the appropriate design and fabrication of a prosthesis are critical to the long term success of any abutment. While Bicon’s detractors may claim that the 2.0mm abutment post breaks frequently, basic geometric principles and the long term success of the 2.0mm Bicon abutment post belie their accusations. In 1997, Bicon introduced a 3.0mm abutment post, for which there has never been a reported fracture. The following technique will assist the clinician if the need arises to remove a fractured 2.0mm post.


Fractured 2.0mm Post Removal Technique

1. Expose the entire circumference of the implant with the 2.0mm fractured abutment post. Do no attempt to remove the 2.0mm post if the entire circumference is not visible.

2. Use two Great White #1557 burs (260-155-7RL) to drill a center hole 3.0mm deep into the 2.0mm abutment post. Copious amounts of water must be used to prevent heating. Coincidentally, the cutting edge of the #1557 bur is the length of the post within the implant.

3. The space between the bottom of the implant well and the 2.0mm abutment post will cause the clinician to feel a “drop in” similar to penetrating a pulp chamber during a pulpotomy, once the bottom of the post has been cut.

4. After the initial penetration, use a #4 round bur with copious water irrigation to enlarge the opening and remove the remainder of the 2.0mm abutment post. If the post has not come out during the drilling, it may be removed with one of a variety of dental hand instruments.

 

Notes: There has never been a report of a fractured 3.0mm abutment post.

 

Unlike threaded bores, if the well of the implant were to be nicked, it would not negatively impact the subsequent placement of a new abutment.

 


Keys to Success

Prior to the removal of a fractured 2.0mm post, evaluate why the post may have fractured in order to prevent future breakage:
• An implant with a 3.0mm post should have been used.
• Occlusal table was too large.
• Cantilever was present on the restoration.
• Excessive occlusal contact, initially, over time, or inadvertently after the extraction or restoration of other teeth.
• Overdenture was implant borne rather than tissue borne.