As we enter the 21st century, minimally invasive devices and procedures are becoming the fastest growing segment of the medical and dental device industry. Compared to traditional approaches, they reduce the risk to the patient, require less anesthesia, shorten surgical and recovery times, and result in significant cost savings. Research and development has been directed at the use of smaller and smaller components. Mini dental implants are an excellent example of this trend. They dramatically broaden the spectrum of mandibular overdenture patients who can be successfully treated. These 1.8-mm implants differ from their full-sized counterparts in a number of significant ways. The configuration of the implant permits a more conservative placement protocol. No tissue flaps or tapping procedures are required, which results in less trauma to both gingival tissue and bone. Their smaller size also permits placement in ridges that might not otherwise be suitable for full-sized implants.
The implants are firmly seated in place in intimate contact with bone. Once they have been fixed in place, they can be immediately loaded. There is no need for a long waiting period or second-stage surgery. The simplified protocols, conservative procedures, and elimination of gingival surgery make this implant ideal for medically, anatomically, and financially compromised patients.
A woman in her early 80s presented to our office frustrated with her lower complete denture. She complained that it was nonretentive and nonfunctional, always falling out while she was speaking or eating. The patient suffered from hypertension, which was controlled with medication. She had been a denture wearer for the last 50 years, resulting in excessive resorption of the mandible.
Palpation and radiographic examination revealed a moderately narrowed mandibular ridge. Crestal bone and ridge height were sufficient to receive 13-mm mini dental implants (IMTEC). The mental formamen was located, and it was determined that 4 implants could be placed safely within the cuspid-to-cuspid area. All risks, benefits, and alternatives were reviewed with the patient before initiating treatment.
|Figure 1. Areas that will receive mini dental implants.||Figure 2. Four mini dental implants placed for stabilization of denture.|
The patient was draped, and a clean operating environment was established. Local infiltration of anesthetic was administered. Markings were placed to designate landmarks and areas of insertion (Figure 1). Keeping correct alignment, the implant drill was advanced through the gingival tissue and the cortical plate. No surgical insertion was necessary. During this stage it was very important to accompany each step of drilling with generous amounts of sterile water. Once penetration has been achieved through the cortical plate, the sterile mini dental implant may be placed with the finger driver until firm resistance is met. The winged thumb wrench was employed. When further advancement ceased, the rat-chet wrench was employed, using small, carefully controlled, incremental advancements until the implant was fully seated. Full seating was achieved when the threads and base of the implant were subgingival and only the abutment head was exposed (Figure 2). The implant must be absolutely tight at this point. If it is not, the quality of the bone indicates a poor prognosis.
|Figure 3. Transfer of implant location to denture using bite material.||Figure 4. Retentive caps placed before reline pickup procedure.|
At this point, the location of each implant was transferred to the denture using bite registration material (Figure 3). These areas were relieved to a diameter of 5 mm, and the denture was re-seated, confirming adequate relief had been established. A small, plastic shim was placed over each implant, allowing only the o-ball of the implant to be exposed. This step prevents the reline material from locking around the implants. A female o-ring keeper cap was then fitted over each implant (Figure 4). Retentive fit and mobility were again verified.
|Figure 5. Dispensing reline material for pickup procedure.|
The cleaned and dried recesses in the denture were then filled with cold cure acrylic (Secure, IMTEC) and allowed to polymerize (Figure 5). Upon setting, the denture was relieved of flash and any voids were filled. The patient was then instructed in denture placement, removal, and oral hygiene.
Mini dental implants provide clinical and economic benefits to your practice and restore function and confidence to your denture patients. Den-ture retention and function are dramatically improved, and the results are immediate. Satisfied patients will refer others to your practice, and you will be recognized as a professional who has the solution to a very common and frustrating problem.