Tissue Graphs

Anterior Reconstruction and Restoration

Full mouth rehabilitations (rehabs) can be some of the most rewarding experiences, but require an immense amount of patience on everyone’s account, compliance, and good healing. This case in particular involved multiple failing endodontically treated teeth in conjunction with peri-apical abscesses which resulted in large amounts of bone loss prior to initiation of treatment.

After long discussions with the patient and preparations, we all elected to move forward with removal of the failing teeth, full debridement of surgical site, placement of immediate implants along with buccal grafting. This undoubtedly was a lot to ask of both the patient and the site, but as we will see, the results were great! Much of the success can be attributed to the patient’s compliance and diligence when following post-op directions. The timeline of events began on March 22, 2011 and commenced at just under a year.

After healing of the initial phase we were able to grow enough bone that it was necessary to remove some of the ridge to find and access the implants. Afterwards the healing around implant #10 yielded a deficiency in keratinized tissue and a bit of an alteration in gingival contour. This was discussed with the patient that grafting should take place prior but could be accomplished after final restoration. The patient made it clear that she wanted some slight imperfections of the teeth to obtain a “natural” look and did not want to have the perfect smile. Needless to say, she was ecstatic at the results.

We will wait for papilla formation between the new restorations and will continue to watch the tissue associated with #10, but for now she is 1 week into the restorations and can’t stop smiling!

A very special thanks to Dr. John Miller in Aspen who guided the restorative treatment and final restorations.

Current Topics in Dentistry

ImplantsWhen contemplating treatment with implants, what clinical and laboratory factors most significantly affect your choice of an implant system?

Author: Bernard T. Carr/David A. Dersh/Wayne R. Harrison/Richard P. Kinsel

This article was published in The International Journal of Oral & Maxillofacial Implants, Vol 16, No 1 (January/February 2001).

Bernard T. Carr, DDS, maintains a private practice in Alexandria, Virginia, emphasizing gnathological, aesthetic, and implant prosthetics. He is a fellow of the American College of Dentists, an Active Member of the Academy of Osseointegration, and a board member of the Northern Virginia Implant Society.

When I draw up a treatment plan using endosseous implants, the following are the most important clinical and laboratory factors that influence my choice of an implant system. The initial need for different implant systems to be developed in implant dentistry arose from the loose screw syndrome with the original external hex design. The loosening of small gold cylinder screws, as well as the larger titanium screws used to secure gold cylinders and machined abutments to the implants, was a constant problem when the restoration lacked a passive-fitting prosthetic framework. This lack of a passive fit would cause microvibrations, which would loosen the screws. These vibrations were the result of built-in stress from the forced fitted framework returning to its original dimension. Obviously, there were far fewer problems with screws loosening in a passive-fitting prosthetic framework.

All of the original-design frameworks were screw-down implant prostheses. The need and desire to restore intact and stronger occlusal morphology with porcelain-fused-to-gold crowns led to the development of the custom-milled cast UCLA abutment for a cemented prosthesis. The advent of the 32 N/cm square drive gold screw, used to secure the custom abutment directly to the implant, as well as improved manufacturing tolerances, has practically eliminated the loose screw problem.

Therefore, designs of the other implant systems, although they may have higher and stronger engineering values, limit prosthetic versatility, both from a laboratory and clinical point of view, in restoring implants that are surgically or positionally compromised. The external hex system provides more versatility for the technician to solve problems with emergence profile and esthetics, since the technician is able to bring the porcelain of a porcelain-fused-to-gold crown closer to the implant interface.

If the use of screws was intended to prevent implant fracture in cases of excessive occlusal load, then the internal hex implant may be more prone to fracture because of its stronger design at the abutment/implant interface.

The MicroMiniplant, used to replace congenitally missing maxillary lateral incisors, has an internal hex interface. It is easier to engage the impression and/or final custom abutment in the internal hex design. However, if the implant platform level is not significantly subgingival, esthetic problems can arise at the abutment/implant interface. These are easier to correct with a custom UCLA abutment and the external hex design system.

Strong consideration should be given to a tapered root-form implant where the apical root forms of the natural roots adjacent to the implant site are too close to permit placement of a cylinder implant.

Personally, there seem to be no problems with the esthetics and longevity of the external hex design implant system, especially if the necessary density and volume of bone is available at the implant site. Clinically, I have had few problems with the external hex implant design and do not see the need for using another implant system.