Failure of Small Diameter (Mini) Implants

Small diameter implants were first developed by NobelBiocare as smooth surfaced implants for use as temporary implants that could be implemented as part of a treatment plan as intermediate support for a temporary prosthesis while the permanent implants achieved osseointegration.  While conventional diameter (3mm or more) implants were cleared for use by the FDA in 1976, more recently, small diameter (1.8 to 2.9mm) implants have been developed with the same surface characteristics as conventional diameter implants, and were cleared for use by the FDA in 1997.  The reasons for use of SDIs are inadequate bone quantity without grafting and a minimally invasive placement procedure.  Because grafting is not an alternative often chosen by patients, mini implants offer a successful alternative.  They can be highly successful if used to support a lower overdenture.

Prevent Implants Failure

Mini implants are subject to failure, however.  Therefore, there are some requirements to prevent failure: enough bone (4mm in width and 13mm in length), 30Ncm of resistance during placement to indicate sufficient bone quality, the largest SDI possible in available bone--preferably  not 1.8mm diameter and length at least 13mm, parallel placement (divergence less than 15 degrees), implants spread out to allow for size of attachment apparatus, no excess tissue thickness at the crest of the bone, and not used in patients who clench or grind.  These clinical requirements have been developed by Dr. Gordon Christensen.


Robert G. Tupac, DDS, FACP, Inc., Diplomate, American Board of Prosthodontics (661) 325-1275 | www.drtupac.com 5060 California Ave., #170, Bakersfield, CA 93309

Implant Options for Denture Patients

Bar structure

In the top radiograph, six upper implants (the ones on the sides tilted backwards) and their distribution allows them to be joined by a bar structure that has teeth attached to it and the hybrid bridge is permanently screwed in place.  It can only be removed in the prosthodontic office.  The prosthesis is more like a row of teeth, has minimal soft tissue coverage, and derives all of its support from the implants.  This prosthesis is most like having your natural teeth back again.

Tissue bar

In the bottom radiograph, four upper implants are joined by a tissue bar.  The resulting prosthesis is called a tissue bar overdenture--it is a removable prosthesis that attaches with clips or snaps to the bar for stability and retention when in place, but can be taken out to allow the implants to be brushed and cleaned.  The prosthesis is horseshoe shaped (open in the center of the palate) but does cover the ridge and adequate lateral tissue for additional support.  Sometimes, when there has been a lot of bone shrinkage, the removable prosthesis allows teeth to be better placed for lip and cheek support, esthetics and phonetics.

Implants options

You don't like your complete upper denture and would like to have some implants.  What are your options?  They depend on the amount of available bone you have remaining and the dimensions in your mouth (clearance for your bite, the sizes of the structural components of the prosthesis, and proper arrangement of teeth) that are required.

Robert G. Tupac, DDS, FACP, Inc., Diplomate, American Board of Prosthodontics (661) 325-1275 | www.drtupac.com 5060 California Ave., #170, Bakersfield, CA 93309

Our Procera Laser Scanner Is State-of-the-Art

Procera Laser Scanner

Since getting the latest generation NobelBiocare Procera Laser Scanner two and a half years ago, we have been making custom abutments on all of the dental implants we have placed.  With custom abutments, optimal contours and tissue emergence profile is achieved, far beyond what is possible with stock abutments.  

The Key Benefit of the System

The scanner also has the ability to scan an entire arch, and we do it in a three stage manner.  First the implant positions are scanned, then the soft tissue contours are scanned over the implant positions and finally a diagnostic waxup of the final positions of the teeth is added.  By doing all of this, we are able to design the bars within the shape of the final prosthesis--whether it is a bar around which an All-on-4 fixed prosthesis is to be processed or an overdenture  tissue bar such as this one, to which the denture will snap into the locator attachments incorporated in the bar.  

We have found that the finest and most current computer technology enables us to provide the most accurate and durable prostheses for our patients. 

Robert G. Tupac, DDS, FACP, Inc., Diplomate, American Board of Prosthodontics (661) 325-1275 | www.drtupac.com 5060 California Ave., #170, Bakersfield, CA 93309

Implant Tissue Bar

LH wanted dental implants to help stabilize and retain his upper denture.  He had the required bone of adequate quality and quantity.  After using radiographic markers to determine implant position with a surgical guide, four implants were placed.  After the implants were ready to restore, according to Osstell Resonance Frequency measurements, they were connected with a tissue bar.  Limited occlusal clearance and the labial position of the anterior teeth required attachments be placed on the palatal aspect of the bar.  Because the overdenture is opposed by natural teeth, a cast superstructure strengthens the overdenture and supplies housings for the nylon attachments.  At 5 year recall, bone levels are excellent and the patient reports he is pleased with his ability to eat, the stability of his appearance and the durability of the prosthesis.

Robert G. Tupac, DDS, FACP, Inc., Diplomate, American Board of Prosthodontics (661) 325-1275 | www.drtupac.com 5060 California Ave., #170, Bakersfield, CA 93309

Implant Options for Denture Patients

Bar structure

In the top radiograph, six upper implants (the ones on the sides tilted backwards) and their distribution allows them to be joined by a bar structure that has teeth attached to it and the hybrid bridge is permanently screwed in place.  It can only be removed in the prosthodontic office.  The prosthesis is more like a row of teeth, has minimal soft tissue coverage, and derives all of its support from the implants.  This prosthesis is most like having your natural teeth back again.

Tissue bar

In the bottom radiograph, four upper implants are joined by a tissue bar.  The resulting prosthesis is called a tissue bar overdenture--it is a removable prosthesis that attaches with clips or snaps to the bar for stability and retention when in place, but can be taken out to allow the implants to be brushed and cleaned.  The prosthesis is horseshoe shaped (open in the center of the palate) but does cover the ridge and adequate lateral tissue for additional support.  Sometimes, when there has been a lot of bone shrinkage, the removable prosthesis allows teeth to be better placed for lip and cheek support, esthetics and phonetics.

Implants options

You don't like your complete upper denture and would like to have some implants.  What are your options?  They depend on the amount of available bone you have remaining and the dimensions in your mouth (clearance for your bite, the sizes of the structural components of the prosthesis, and proper arrangement of teeth) that are required.

Robert G. Tupac, DDS, FACP, Inc., Diplomate, American Board of Prosthodontics (661) 325-1275 | www.drtupac.com 5060 California Ave., #170, Bakersfield, CA 93309