Human Resource Management - Its Impact on ... - Dental Asia

USERREPORTWe have already noted two factors. But micromovement andmicrogaps are not the only enemies of stable tissue. Possiblenegative effects of the implant-abutment transition are alsoreduced by moving this connection away from the peri-implanttissue to prevent any irritation. This is done by displacing theimplant-abutment connection to the center by using anabutment with a smaller diameter than that of the implant. Thisdisplaces the biological width from the vertical to the horizontalplane. This procedure is referred to as platform switching.Platform switching is an important factor in tissue stability – butonly in combination with a connection design that preventsmicromovement and is bacteria-proof, which we call platformshifting ® .Figure 1 (left) X-ray image of the Ankylos implant-abutment connectionbefore starting the test (x-ray image: Holger Zipprich/Dr. Paul Weigl,Frankfurt am Main/Germany)Figure 2 (right) X-ray image of the Ankylos implant-abutment connectionafter 1,000,000 load cycles (x-ray image: Holger Zipprich/Dr. Paul Weigl,Frankfurt am Main/Germany)A bacteria-proof friction-locked and keyedconnection is only possible with the taperedconnection completely flushinterface level. Thebone responds withresorption below theimplant-abutmentconnection until thebiological width hasbecome established.The potential forinfection is reducedwithout the microgap– and in combinationwith no micromovementit iscompletelyeliminated. Withoutmicrobial leakage ofthe implant lumenthere is no microbialcolonization andwithout endotoxinsno potential forinfection. For these reasons when dealing with cases with lowbone volume, thin gingiva or particularly high esthetic demandsthe implantologist must look for connection that is as bacteriaproofas possible and with as little gap as possible whenselecting the implant system. This will keep the hard and softtissue stable.The smaller abutment also provides more space for periimplantsoft tissue and as a result improves the red esthetics.However, red esthetics alone is generally not sufficient,particularly for the esthetically sensitive front-tooth region.This is the area where the patient wants perfect whiteesthetics, a tooth that appears as if nothing had everhappened. The emergence profile is the key in this case. Theformation of a natural emergence profile often requiredsubcrestal placement of the implant to take full advantage ofplatform shifting. However, for implants with a connection thatallows micro-movements and a microgap this is a real“implant killer.”The bone will remain stable in spite of subcrestal placement ofthe implant only if there is absolutely no irritation, which meansa bacteria-proof and rigid connection design that alsoeliminates irritation by using platform switching. This results ina natural emergence profile that also leaves additional spacefor stable, thick soft tissue over the implant shoulder. It is clearthat this is not required in every case.Even if there are implant systems that can be placedsubcrestally, bone deposition above the connection level wasformerly not considered feasible because the microroughnessof the implant surface always ended below the implantshoulder. Implant concepts that make use of tissue depositionin the shoulder region of the implant simply extend thegrowth-activating implant surface over the shoulder regionof the implant.What happens then is demonstrated by the most recentstudies. Bone and connective tissue cells adhere to and spreadfaster and more extensively on a microroughened implantshoulder than on a machined surface. In combination withplatform switching, subcrestal placement and a connectiondesign that eliminates micromovements bone can even growon the horizontal shoulder surface and on the abutment. Thissupports the overlying soft tissue and gives patients longtermstability of esthetic results.Analytical • Authoritative • AcclaimedFor more information, email: info@pabloasia.comDental Asia • March / April 200841