Since the two recent JADA articles by Dr. Shepherd and Drs. Muftu and Chapman1 2 and Dr. Berman s letter to the editor3 are being used to promote and market the Bicon implant system to our membership, I would like to offer some observations and words of caution.

Dr. Shepherd s December 1998 article first extensively criticizes screw-retained implant systems and then presents the advantages of his screwless Bicon implant system. His principal theme is that the Bicon system is easier, simpler and less expensive, making it more accessible to our patients and to us. He even presents a dollar estimate equating a simple implant restoration to a three-unit fixed bridge and claims his implant system is "affordable to most dental patients."
However, both JADA articles recommend that these implants not be splinted, but be placed and restored on a single, tooth-by-tooth basis. Doing so can become costly.
Dr. Shepherd s first case shows three adjacent implants with three separate crowns. Using his numbers for estimated surgical and prosthetic costs of $900 to $1,100 per implant and $600 per crown, the fee for this case would be $4,500 to $5,000. His second case is an 18-implant, 24-crown, fixed-splinted maxillary and mandibular restoration. Projected cost: over $30,000. Given that Bicon materials cost $210 to $315 per unit, one must conclude that the Bicon implant system, like the other systems, is actually out of reach financially for many of our patients.
This is especially true if we follow Dr. Shepherd s guideline of one implant for each missing tooth. Other systems, in which implants are splinted, would use fewer implants for these two cases and, contrary to Dr. Shepherd's claim, become simpler and possibly less expensive than the Bicon system.
Drs. Muftu and Chapman s August 1998 JADA report2 is on an excellent hospital-based prospective study of 432 Bicon implants put into 168 patients by one surgeon and in place from less than one year to as long as four years. They report a 90 percent six-year implant survival rate in the mandible with very few prosthetic complications. Six- and eight-year follow-ups on this patient group are planned for and are necessary. However, though their success criteria require the absence of progressive bone loss, they did not report any bone level measurements in their article.
All implant systems have their problems, and Bicon is no exception. This implant has been available for many years as the Stryker implant and was
never widely used. It is neither the common screw design, nor the tightly press-fit cylinder design, but a unique tapered "finned" implant that requires dry, very low-speed machine and hand drilling in order to harvest the bone chips for grafting on top of the implant, which is placed 3 to 5 millimeters below the alveolar crest. This grafted covering may prove to be an unpredictable weak point.
Also, the narrow 2-mm abutment neck may be subject to fracture, especially if angled. Since it is made from the titanium-aluminum-vanadium alloy, rather than pure titanium, research also needs to be done on the long-term progressive bone loss, implant fracture and exfoliation of Stryker implants.
As Dr. Berman3 states in his letter to the editor, multiple long-term, university-based trials of the Bicon implant are indicated. I agree and feel that the corporate sponsor and not the public should fund such clinical trials of commercial products. With this kind of corporate-university partnership, reliable answers can be acquired and we can practice evidence-based dentistry instead of old-fashioned anecdotal case-report dentistry. Then real progress can be made to answer such questions as:
What are the implant and bridge success rates in 100 consecutively treated patients with restored implants in their mouths for more than five years utilizing a titanium alloy, finned implant placed solely with hand pressure 3 to 5 mm subcrestally into bone that has been drilled without cooling with a bone graft plug to fill the hole and later restored with a press-fit abutment having a 2-mm-diameter neck and then crowned individually without splinting?
Theodore L. West, D.D.S., M.S.D.
Columbia University School of Dental and
Oral Surgery
New York

1. Shepherd NJ. Affordable implant prosthetics using a screwless implant system.
JADA 1998;129(12):1732-8.
2. Muftu A, Chapman RJ. Replacing posterior teeth with freestanding implants: four-year prosthodontic results of a prospective study. JADA 1998;129(8):1097-102.
3. Berman CL. Curbing implant complications (letter). JADA 1998; 129(12):1666.

This was published in JADA, Vol. 130,April 1999 pp 466-468