How to Use Mini-Implants to Secure a Partial Chaim Wexler, DDS
Official Townie

This case presentation tells a lot about the vast potential of the IMTEC mini dental implant to affect everyday dental treatment. Common problems that occur in a dental practice such as loose or painful dentures, failing bridgework or even missing teeth can literally be solved in minutes. For the uninitiated, these small diameter (1.8mm) implants were developed by Dr. Victor Sendax and are sold through IMTEC. They are usually placed non-surgically by the general dentist, need little anesthesia, and can be immediately loaded. The head of the implant is ball shaped and fits into an O-ring housing embedded on the bottom of a denture.

The cost of these implants is a fraction of that of a conventional implant and the savings can be passed on to the patient. Suddenly, a huge population of patients who couldn’t afford the fees for implants or were medically ineligible can now obtain the comfort and stability these devices give.

IMTEC primarily markets the mini- implant as a retention device for full dentures. However, as moderator of the IMTEC mini dental implant forum at www.dentaltown.com, I have advocated many more uses for these implants ranging from partial denture clasp elimination to one-hour total tooth replacement in conjunction with the CEREC system.

In the following case, a 65-year-old woman presented in February 2002 with an ill fitting partial that had a clasp on right distal abutment #27. Her dental history revealed that tooth #27 had a root canal, post and crown completed in April 2001. The original treatment plan was to make a new partial denture but it was discovered that her insurance plan would not cover the replacement denture for a few years. She elected to wait with the old partial for financial reasons.

By February 2002, however, she could no longer tolerate the looseness of the denture. Since she was otherwise very pleased with the fit and comfort of the prosthesis, all she wanted was for me to do anything I could to make it tight.

Figure 1: Pre-op picture of the partial denture. The denture is only a few years old and in fine condition.

Figure 2: Demonstrates the poor adaptation of the clasp assembly to the abutment tooth #27. Simply bending the clasp would not alleviate the looseness problem.

Figure 3: Shows a radiograph of the abutment. Note that the crown on #27 is all porcelain and the crown to root ratio of this abutment is certainly not favorable.

Figure 1

Figure 2

Figure 3

My answer to this dilemma was to place mini-implants in the edentulous ridge distal to the abutment tooth #27. The rationale for this was simple. The ability to obtain retention from the gums is an elegant solution to the multiple problems associated with conventional partial dentures. The O-ring housing on the ball head implants effectively resists dislodging forces. Normally the abutments resist these forces. Cases such as this, where the bone support is compromised, it is a fairly safe bet that the abutment tooth will eventually be lost. In addition, the clasp on the abutment can be removed yielding a more esthetic final result while avoiding potential damage from the metal to the all porcelain crown.

In the past, implants would not have been considered a viable option. Often it would have meant a referral to an Oral Surgeon, surgical placement, four to six months of healing and a large outlay of money. With the advent of the mini-implant, the fixtures can be placed in less than the time it takes to read this article.

The patient readily accepted this treatment plan. She was mainly pleased that she could keep her existing denture and not have to start over with the impressioning and fitting of a new prosthesis.

Figures 4 through 9 (page 70) are from a different case but illustrate the basic steps involved in placing a mini-implant.

After making a small incision with a drill through the cortical plate, the mini-implant is initially inserted with a thumb wrench (Fig. 4). Subsequently, as the bony resistance increases, a winged wrench (Fig. 5) is used and when necessary a small ratchet device (Fig. 6) is used to achieve final placement. Since the mini-implant is self-tapping, its stability and longevity depend on it being placed in dense bone. Plastic shims (Fig. 7) are placed over the exposed area of the implant head and the O-ring housing is placed on top the implant (Fig. 8). Finally, the housing is cold cured to an opening cut into the bottom of the denture (Fig. 9).

Figure 4	Figure 5	Figure 6
Figure 7	Figure 8	Figure 9

A similar technique was employed in the placement of the two mini-implants into the lower right edentulous ridge and the O-ring housings were imbedded in the acrylic base of the partial. Figures 10-14 are of the six month follow up to the placement of these implants. Note that the gums appear healthy and the implants were firmly in place. The patient did not report any problems with her denture.

Figure 10	Figure 11	Figure 12
Figure 13	Figure 14

In conclusion, the advent of the mini dental implant has given the general dentist an easy, painless, less costly and rapid way of solving many difficult problems that arise in dental practice. The case presented here shows the use of the mini-implant in stabilizing an ill fitting partial while avoiding the use of a non-ideal abutment tooth. The entire procedure took less than half an hour and the six-month recall shows a successful result.

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Dr. Chaim S. Wexler is a 1984 graduate of Columbia University SDOS where he is a clinical assistant professor. He is an ISCD certified CEREC trainer and a mini dental implant course instructor. Dr. Wexler is the director of the Metro CEREC Institute, which specializes in teaching advanced techniques in the CEREC system and also the Sendax mini dental implant. He can be reached at (212) 740-7427 or email cw362@columbia.edu.