Marshall L. Madow, DDS
For the general practitioner (not to mention our patients), a major source of difficulty and frustration is the fabrication and placement of a complete lower denture that fits well, is comfortable, aesthetic, and fully functional. As we all know, trying to attain all four of these traits in the same denture often seems like an impossible feat!
In the early 1990s, I became associated with a group of dental practices whose main focus was treating complete and partial denture patients. During my tenure with that organization, I fabricated and inserted literally thousands of dentures for my patients, a good number of which were complete lower dentures. As a result, I gained a great deal of valuable insight and understanding of complete lower dentures (and denture patients) that subsequently may come only with the experience of having placed such a large number. But the fact remains that no matter how many complete lower dentures I have successfully placed in the past, they still have their inherent imperfections. I have had my difficulties with many of them, just like anybody else. And no wonder, with so many factors working against us, including (but by no means restricted to) these:
- Resorbed ridges (of varying degrees)
- Decreased salivary flow
- Little or no suction
- Inadequate coordination
- Poor attitude (the patients' and ours)
Up until now, we've had a limited number of tools in our armamentarium to help patients with their complete lower dentures. We've all tried the various adhesives, pads, soft relines, and hard relines. But let's face it - they may help, but nothing short of some type of attachment system is really going to hold that denture in place adequately. The problem is that most of what is currently available usually is quite costly and involves surgery, significant healing time, and/or lab time.
So, isn't it wonderful when something comes along that has the ability to make vast improvements on an age-old problem? Something that can make the lives of so many of patients so much easier? In this article, I will tell you about one that has totally changed (for the better) the way I feel about making complete lower dentures. It could do the same thing for you - and improve your practice's bottom line, all at the same time.
Fewer than 10 percent of general dentists in this country participate in the surgical placement of implants. According to Dr. Gordon Christensen in a February 2001 article in DentalTown Magazine, some of the reasons are lack of interest, fear of difficulty, and fear of legal action. What if there were a type of implant capable of doing many of the things a conventional implant is capable of doing? What if it required no surgery to place (therefore, no healing time)? What if the technique were relatively easy to learn? What if it could be performed in one visit, and cost a fraction of the amount of a conventional implant? Well, a type of implant with all of these qualities exists. These "mini" implants are being successfully used on both a transitional and long-term basis. Three of the manufacturers currently making these implants are Dentatus USA, Ltd. (Mini Transitional Implant), IMTEC Corp. (Sendax MDI Mini Dental Implant System), and Nobel Biocare (Immediate Provisional Implant).
Last summer, I attended a one-day, hands-on course given by IMTEC Corp. in New York City for its Sendax MDI Mini Dental Implant System. The system's primary purpose has been to hold a patient's complete lower denture securely in place, although it has other practical uses that I will touch on as well.
The system is really quite remarkable in its simplicity. Basically, four titanium-aluminum-vanadium alloy self-tapping "mini-implants" are threaded into the patient's mandible through the attached gingiva ("Four on the Floor," as they call it). The mini-implants are all 1.8 mm in diameter and come in varying lengths, ranging from 10 mm to 18 mm. There's no surgery (and very little anesthesia) required. You basically make a small pilot hole through the attached gingiva with the supplied drill in a slow-speed handpiece, just penetrating the cortical plate. Then using a series of wrenches, you slowly thread the mini-implant into position. Each mini-implant has an O-Ball prosthetic head on it, which protrudes slightly above the gingival tissue. Once all four mini-implants are in place, the patient's existing lower denture (or new denture, if that be the case) is retrofitted with four metal caps containing rubber O-Rings.
The positions of the O-Ball heads are marked on the tissue surface of the denture. Adequate space is relieved, and the metal caps containing the O-Rings are secured in place with cold-cure acrylic. When placed back in the mouth, the denture now gently "snaps" onto the O-Ball heads, holding the denture securely in place. The entire procedure normally takes less than two hours. There's no healing time - the patient walks out of your office the same day with a secure lower denture that won't move around, rub, pop up, or fly out of the mouth every time he sneezes or coughs. There's very little postoperative pain - usually the only discomfort felt (if any) is in the areas where the local anesthesia was administered. And, as stated earlier, the cost to the patient is much less than what conventional implants would cost. It's a great practice builder and a great profit center as well. I charge $600 per mini-implant, which includes retrofitting the existing denture (obviously, one can charge anything they feel is appropriate).
The MDI system has many other uses, including support for periodontally and/or endodontically compromised natural teeth, supporting a fixed prosthesis, or securing a palateless complete or partial maxillary denture. In fact, the company now manufactures a mini-implant specifically for use in the maxilla, with a wider thread design for Type II bone, which is called the "MAX" Mini Dental Implant. I recently used MAX mini-implants to successfully secure a palateless upper partial denture for one of my patients, and, along with my colleague, Dr. Edward Lazer, we have used the mini-implant system to help support long-span bridgework. We have found them to be an extremely useful, welcome, and profitable addition to the practice.
I highly recommend that you take a continuing education course before attempting to place these on your patients. The course I attended was extremely informative and well-organized. It was presented by Dr. Victor Sendax, a diplomate of the American Board of Oral Implantology/Implant Dentistry and the developer of the Sendax MDI Mini Dental Implant System. To view a schedule of upcoming seminars and mini-residencies for the Sendax MDI system as well as other related information, you can visit the company's Web site at imtec.com.
Just think - a system that keeps complete lower dentures in place without the high cost, postoperative pain and months of healing time associated with conventional implants, all in about two hours' time. I think it's safe to say the entire range of applications for the new mini-implant systems is still yet to be seen.