Oral Health Group

Letters to the Editor (September 01, 2003)

September 1, 2003
by Oral Health

Re: Implant Complications and Maintenance Issues, July, 2003

Drs. Lai and Albert do not make a distinction between research-driven implant system designs and those that were developed for practical clinical applications. That is still common with most implant authors today.


Our profession is indebted to the research-driven implant system designs (RDISD) for “The high predictability and long-term success of implant therapy…” mentioned by the authors. However, the use of these systems in the “real world” of our practices is almost entirely responsible for the mechanical complications, which the authors deal with so thoroughly.

The occurrence of implant fracture, prosthesis misfit, screw loosening, screw fractures, framework/prosthesis fracture, ranges from rare to impossible with implant systems designed for the “real world”. Real world systems (RWS) owe their very existence to observing the biologic principles of osseointegration painstakingly uncovered by the use of RDISD. RDISD need retrievability so that prostheses can be removed to allow inspection of each individual implant for mobility and to probe peri-implant tissues more easily. Screws that make retrievability possible also allow the attachment of special film holders to each fixture so that the x-ray source to fixture to film relationship is reproducible. Reproducibility is the essence of science.

Of course, we cannot circumvent biologic principles. We now know what these are, thanks to the RDISD. RDISD with their retrievable screw-retained components will make new research possible. But RWS are coming on stream for practical clinical applications. They use few or no screws. Prostheses are cemented just like they are in conventional prosthodontics. Cementation has the weight of history behind it. No one looks for retrievability in conventional crown and bridge prosthodontics nor do we need it in real world implant prosthodontics.

Except for the common failure to make a distinction between the needs of the researcher and the wet-gloved clinician, I congratulate the authors on an excellent paper.

Milan Somborac DDS

Collingwood, ON