TissueCare News 03/2009

GUEST EDITORIAL

Dear reader,
The term "innovation" is very popular in dental implantology. But very few developments really deserve to be called innovations. An innovation is more than just a visionary idea. It must be something that makes a lasting impact. 
PlatformShifting has proven to be such an innovation with its long-term, reliable results and has become established as a firm component of the TissueCare Concept. Its most important characteristic: the narrower diameter of the abutment compared to that of the implant allows bone tissue to be deposited on the implant shoulder – when the implant is placed subcrestally.
This requires a bacteria-proof connection between the implant and abutment to prevent bacterial contamination at the interface. The advantage of this construction is inherent in the ANKYLOS system with its friction-locked and keyed tapered connection.
The TissueCare Concept gives the dentist all the requirements for successful functional and esthetic regeneration of hard tissue and soft tissue. The PlatformShifting concept retains the prior bone margin for the long term and can stabilize the soft tissue.
This issue of the newsletter is presented to familiarize you with the basic features of PlatformShifting and to demonstrate the various treatment options.

Dr. Dietmar Weng

Stable soft tissue with bone retention

Micromovement and microbial flow
If conventional, two-component implants are placed subcrestally, resorption of the alveolar bone ridge often occurs. The reason for this is the microgap between implant and abutment. With all the technical requirements for adjusting the play paraxial forces, such as when chewing, may cause micromovements. They generate a pumping effect, which causes microbial flow that results in a circular inflammation of the connective tissue in the region of the implant-abutment interface. The result: the bone experiences a "defense reaction" and is resorbed apically until the biological width is reduced to a lower level and has stabilized at that level. However, a two-component implant system that does not permit micromovements and is bacteria-proof at the interface virtually eliminates the risk of peri-implant bone resorption.
The ANKYLOS implant with its typical, perfectly keyed and rotation-locked ta-pered connection fulfills this basic re-quirement for functional PlatformShifting.

Tapered connection and PlatformShifting
The diameter of the prosthetic abutment is significant narrower than the implant diameter. This provides more volume around the implant-abutment interface for the circular, subepithelial soft-tissue clo-sure. Overgrowth of the regenerating epithelial tissue is prevented.
"The increased volume of collagen fiber tissue present in the connective tissue matrix supports and stabilizes the mucosal collar and secures the long-term soft, bacteria-proof adhesion in the emergence region,“ according to Prof. Dr. Georg-H. Nentwig.
The displacement of the microgap towards the center prevents mechanical and microbial irritation of the peri-implant hard-tissue and soft-tissue structures. The biological width is moved from the vertical to the horizontal1 and can form a horizontally stable structure. This provides the essential conditions for long-term healthy and irritation-free hard tissue and soft tissue. According to studies by Tarnow et al.2, the horizontal extension of the biological width is 1 to 1.5 mm on average. This gives rise to the required minimum distance of 1.5 mm to the natural neighboring tooth and 3 mm between two implants. The implant shoulder is generally placed 0.5 to 1 mm subcrestal. This favors the establishment of a natural emergence profile.

Biological width and implant surface
A distance of 4 to 5 mm is recommended from the crown contact point to the interdental bone tip. Compliance with this specification is one of the prerequisites for bone support of the peri-implant soft tissue and a stable reconstruction of the interdental papillae. The desired bone apposition at the implant shoulder is then only possible if a microstructured surface extending to the implant shoulder allows the adhesion of bone-forming cells. ANKYLOS implants have had the microrough FRIADENT plus surface for many years, including on the implant shoulder.

Free choice of prosthetic abutments
An unmistakable characteristic of ANKYLOS PlatformShifting is that all abutments in the system fit on all implant sizes. This allows the dentist to select the abutment diameter, height, angulation and sulcus emergence height depending on the actual clinical situation. When faced with a seriously atrophied maxilla with low residual bone volume, the success of the treatment depends on the hard tissue and soft tissue remaining free from irritation and preventing any further resorption.
This is why the dentist in this case selected the ANKYLOS system. Eight implants were placed slightly subcrestal and with primary stability, two of them in the posterior alveolar process with internal sinus lift. The superstructure consisted of segmented, multi-link bridge sections of zirconium dioxide on titanium abutments.

PlatformShifting by DENTSPLY Friadent: a response to specific challenges

Strongly atrophied maxilla
The narrow abutment base in relation to the implant shoulder means that the dark titanium abutments do not show through the mucosa. This allows a thicker, less translucent soft tissue coverage with a greater volume to form. Another esthetic effect is that the gingiva can actually be pressed into the correct shape, as is clearly shown in the picture.
A stable surround of the marginal gingiva and well-formed interdental papillae indicate not only the successful esthetic result of a rehabilitation. They are primary indicators of stable bone conditions and healthy peri-implant soft tissue
.