|by Ara Nazarian, DDS
As the Baby Boomer population increases in number and size so does the number of
edentulous and partially edentulous patients, since tooth loss and age are related. Whether it
is due to neglect, caries, medications or other systemic reasons, patients are presenting to practices
all over America needing extractions that can even lead up to full-mouth edentulation.
Patients that undergo full-mouth extractions are concerned of ill-fitting or loose dentures
and the inability to eat or function without teeth. Because of these concerns, most dentists
do not want to be the provider who converts patients to a complete denture, unless they
incorporate some type of implants into the plan. Implants, whether small or traditional,
allow patients with dentures to eat and function like they can with a full set of teeth. In other
words, having some type of implant-retained prosthesis makes the transition from having
teeth to total edentulism much easier without the common denture problems of instability,
sores and pain.
Endosseous implants have been successfully used to restore edentulous ridges with
implant-supported fixed bridges, hybrid prosthetic dentures and removable overdenture
prostheses for many years. However, due to deficiencies in the remaining bone, complicated
medical history or financial reasons, not everyone is a candidate for traditional implants.
Practicing in Michigan, where the economy has not been the greatest for several years, I have
personally found that small diameter dental implants offer a great alternative to traditional
Small diameter implants placed with flapless surgery to support dentures presents an alternative
method of restoring patients with atrophic jaws. They dramatically broaden the spectrum
of overdenture patients who can be successfully treated. These small diameter implants
(1.8mm-3.0mm) 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 fewer traumas 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 makes small diameter implants ideal for medically, anatomically
and financially compromised patients.
A man in his early 50s presented to our office frustrated with his upper partial denture
and maxillary teeth that opposed a natural lower dentition from teeth #19-#30 (Fig. 1). He
complained that his upper partial denture was non-retentive and non-functional always
falling out during speech or during eating. In fact, he mentioned that when he did use moderate
amounts of adhesive to keep the prosthesis in, it would cause him to gag severely. Also,
the maxillary teeth (#2, 8, 9 and 10) that were present had several areas of decay causing intermittent
pain and discomfort (Fig. 2).
Palpation and radiographic examination revealed a moderately narrowed maxillary ridge
in the edentulous areas distal to his maxillary anterior teeth (Fig. 3). Because of this, it was
important to maintain as much bone as possible after the intended extractions. By using the
Physics Forceps (Golden Dental Solutions), the remaining maxillary teeth (#2, 8, 9 and 10)
were atraumatically extracted preventing any buccal bone loss (Fig. 4).
The Physics Forceps act like a Class I lever, where only one force is applied with the beak
on the lingual aspect of the tooth. Once the beak is placed, the bumper is placed on the alveolar
ridge at the approximate location of the muco-gingival junction to balance the beak. The
beak grasps the tooth while the bumper is the fulcrum to provide leverage and stability for
the beak and wrist movement.
Once the instrument is properly placed, pressure is slowly applied using only wrist movement
applying a steady and gentle pressure toward the buccal. Within approximately 30 to
60 seconds, the internal force or "creep" will build up allowing the bone to slowly expand and
the periodontal ligament to release, at which point the tooth will disengage from its socket
(known as the "pop"). Once the tooth has disengaged from the socket, the instrument has
completed its task and another instrument of choice (e.g., rongeurs) or your fingers can be
utilized to remove the tooth. Demineralized Freez Dried Bone Putty (OCO Biomedical) was
placed in the sockets of #8 and #9 to further enhance preservation of the ridge.
Using the interseptal bone between the sockets of #8 and #9 as well as the extraction site
of #10, seven dental implants would be placed in the pre-maxilla area to aid in the retention
of the prosthesis. Our selection consisted of OCO Biomedical's I-Mini dental implants.
These small diameter implants (3mm) were selected for this particular case because of the
active aggressive thread design. In addition to the patent-pending bull-nose auger tip of the
I-Mini that condenses bone at the tip, the thread pattern and pitch of the implant are
designed to immediately maximize bone to thread contact. In summary, it is important to select an implant that allows for immediate loading with deeper threads by resisting lateral
occlusal forces especially when softer bone is present.
Keeping correct alignment, a 1.8mm pilot drill was placed into the sites and advanced to
the full depth using a surgical motor (AEU-7000E, Aseptico) with generous amounts of cooled
sterile water. Paralleling pins (OCO Biomedical) were placed in the sites of the osteotomies and
an X-ray taken to check the angulations to ensure proper orientation amongst the implant
sites. The final drill in the OCO Biomedical surgical drill is side-cutting only and used to form
the final osteotomy since the depth was set by the pilot drill. Once the osteotomies were completed,
seven (3mm) I-Mini dental implants of various lengths were placed in the osteotomies
using an implant finger driver until increased torque was necessary (Fig. 5). The ratchet wrench
was then connected to the adapter and the implants torqued to final depth reaching a torque
level of 55Ncm. A post-operative radiograph was made of the implants before initiating the
prosthetic phase of treatment.
Using a soft liner (GC RelineSoft, GC America) the immediate upper denture was relined,
so that the area would have a chance to heal for the next few months (Fig. 6). The patient was
instructed on how to use his new temporary prosthesis and what type of foods to eat.
As the tissue and bone around the implants was completely healed at three months (Figs.
7 & 8), a medium body polyvinyl siloxane impression (Take 1 Advanced, Kerr) was used to
take the definitive impression for the hybrid metal-reinforced denture. The metal reinforcement
would allow this prosthesis to be much smaller than a traditional maxillary denture and
with no palate coverage. The dental laboratory would design a framework where the areas
would be open 5mm for the housings to seat passively.
At the time of delivery, a small piece of rubber dam was placed over each implant,
allowing only the O-ball of the implant to be exposed. This step prevented problems of
the hard pick-up material locking around the implants. Female O-ring keeper caps (OCO
Biomedical) were then fitted over each implant. Retentive fit and mobility were again
verified. Each O-ring would create a retentiveness of approximately six pounds. Since there
were seven implants with corresponding housings, the total amount of force needed to
remove the prosthesis would be 42 pounds.
The cleaned and dried recesses the dental lab created in the denture were filled with cold
cure acrylic (GC RelineHard, GC America) and seated onto the implants and allowed to
polymerize (Figs. 9 & 10). Upon setting the denture was relieved of any excess flash. The
patient was very pleased with the fit, function and aesthetics of the final Hybrid denture prosthesis
(Figs. 11 & 12).
A mini dental implant service provides clinical and economic benefits to your practice and
restores function and confidence to your patients. Denture retention and function are
dramatically improved, and the results are immediate. The advent of the mini dental implant
has given general dentists an easy, less costly and rapid way of solving many of the difficult
problems that arise in dental practice with complete dentures.