IM0110

I 23 research _ platform switching I implants1_2010 Fig. 3_The platform switching con- cept (X-ray courtesy Dr. R. Vollmer, G. Golecki) bone loss occurring around two-stage implants, following loading, or surgical stage 2, may be re- duced or eliminated when implants are restored with smaller-diameter abutments on larger plat- forms.4, 5 Theinterfacebetweenabutmentandimplant,or the microgap, is subject to micro movements and bacterial seeding, and, if it lies at or below the crest of the bone, prompts osseous resorption for these reasons. Bone preserving techniques such as platform switching have been utilized for more than ten years (Fig. 3). The answer to these questions may be of an im- portant support in choosing the implant system, abletoswitchtheplatform,whichcanfacehighim- plant—aesthetic demands. Istheconceptofplatformswitchingabonepreserv- ing technique and, if so, is this reproducible? Is this concept alone able to preserve bone? Is the platform switching concept evidence based? _Materials and methods The aim and objectives of this review have been toexaminethescientificvalidityofclaimsthatplat- formswitchingconceptimprovesimplantperform- ance, being a bone preserving technique. Theseclaimshavebeenanalyzedagainsthistoric background, findings and conclusions of published implant studies. A literature search of paper published in refer- ence journals in the English language was per- formed by computer using the National Library of Health. PubMed—the government search engine for the NationalLibraryofHealth,NationalInstituteofHealth MEDLINE database: http://www.pubmed.gov, has beenusedastheprimarysourceofdata. Google Scholar Search engine and different Journals and books have been employed as a sec- ondary source. PubMed search for the key words “implant plat- form switching concept” ended in 10 and Google Scholar in 3,110 results for the same key words in 0.07 seconds. These results show an ever—growing interest in thissubjectwhichisverychallengingforthepeerre- viewed literature to keep up with. Manual search of IJOMI—International Journal of Oral and Maxillofacial Implants with back issues from 1996 to 2009 revealed very few results. The reference list of identified publications and textbooks were scanned. Thefirstselectionmethodconsistedinarelevant references selection on the basis of titles and ab- stracts. The final selection method being possibly rele- Maxilla PS* 3i ext.hex 50 0,6+/-0,2 0,6+/-0,2 0,6+/-0.2 0,6+/-0,2 0,6+/-0,2 Mandible PS 3i ext.hex. 47 0,5+/-0,2 0,5+/-0,2 0,5+/-0,2 0,5+/-0,2 0,5+/-0,2 Maxilla non PS** 3i ext.hex. 42 0,9+/-0,3 1,0+/-0,3 1,0+/-0,3 1,1+/-0,3 1,2+/-0,3 Mandible non PS 3i ext.hex. 43 0,8+/-0,2 0,9+/-0,3 0,9+/-0,3 1,0+/-0,3 1,0+/-0,3 PS* = Platform switched abutments (narrower) PS**= Same platform abutment (non- switched) Site Type of No.of Bone res. Bone res. Bone res. Bone res. Bone res. implants implants (mm) (mm) (mm) (mm) (mm) after 1 year after 2 years after 3 years after 4 years after 5 years Fig. 3 Tab. 1