Solving Dilemmas in Clinical Practice

 CASE 2 

Background
Eli’s chief concern related to an implant-supported crown on tooth No. 8. The crown had previously come off many times. When he entered our practice, he told me, "Not only did my cap come off, but the post underneath also came out. I’ve had to have it banged back in more times than I care to remember." He was referring to a PFM crown that was placed over an abutment placed on an implant. On this day, the crown had come off and the abutment had loosened but was still in place. The abutment he had placed was a "locking taper" implant, also known as friction, as explained by Bicon Dental Implants (bicon.com/ product_info/pi_faq.html). It should be reiterated that I inherited this implant. This author’s preference is for implant systems that utilize screw-retained abutments such as Replace Select (Nobel Biocare), and many other systems too numerous to mention. For a listing of many implant companies, you can visit implantdentistry.com/man.html.

Examination and Analysis
Clinical examination revealed a very slight shade variation between the crown on tooth No. 9 and the natural teeth Nos. 7 and 10. This was of no concern to Eli. The abutment on No. 8 was too short (Figure 11), and the implant itself was positioned more to the palate than I would have liked (Figure 12). Based on the patient’s account I sensed that, in addition to the inadequate length of the abutment, there were forces that contributed to dislodging the crown in excursive movements, similar to undesirable forces on a cantilever bridge. Considering that the crown and abutment loosened multiple times, it seemed inappropriate to repeat the same remedies that had been used before. The quote that comes to mind to best describe this dilemma is, "Insanity is doing the same thing over and over again but expecting different results." (This statement has been attributed to Benjamin Franklin, Albert Einstein, and an old Chinese proverb. However, it seems that one Rita Mae Brown first said it in her 1983 book Sudden Death.) 
     What were the possible solutions to this dilemma? The existing implant could be removed and a new implant placed in a more favorable position. After osseointegration, a new screw-retained abutment with adequate length could be placed and a new crown made. Eli was not excited about this option. Could something different be done using the existing implant to improve the chances for abutment and crown retention?