implants - international magazine of oral implantology

special _ endo-implant algorithm I expected and an increased implant-abutment dis- parity allows more stable peri-implant soft-tissue integration. Baggi et al. conducted a finite element analysis experiment to define stress distribution and magni- tude in the crestal area around three commercially available implants: ITI Straumann (Straumann), No- bel Biocare (Nobel Biocare) and Ankylos C/X (DENTSPLY Friadent).58 Numerical models of maxil- lary and mandibular molar bone segments were generated from computed tomography images and local stress vectors were introduced to allow for the assessment of bone overload risk. Different crestal bone geometries were also modelled. Type II bone quality was approximated and complete osseointe- gration was assumed. It was concluded that the Ankylos C/X implant based on its platform switched and sub-crestally positioned design demonstrated better stress-based performance and lower risk of bone overload than the other implant systems eval- uated. Platform switching with a stable implant-abut- ment connection is increasingly accepted essential implant design features required to reduce or elimi- nate early crestal bone loss. A bacteria-proof seal, alackofmicro-movementduetoalongfrictiongrip tapered channel, and minimally invasive second- stage surgery without any major trauma for the periosteal tissues are also important factors in pre- venting cervical bone loss. A preconfigured plat- form-switched design has a significant impact on theimplanttreatmentinaestheticareas,asnotonly is the tissue biotype preserved, but it has also been shown to be enhanced by osseous generation over the collar of the fixture (Figs. 12a & b).59,60 The endo-implant algorithm parallels the ques- tion: Which came first, the chicken or the egg as an example of circular cause and consequence. It could be reformulated as follows: Which came first, X that cannotarisewithoutY,orYthatcannotarisewithout X? An equivalent situation arises in engineering and scienceknownascircularreference,inwhichthepa- rameterisrequiredtocalculatethatparameteritself. Thisistheessenceoffoundationaldentistry.Ifnature creates the ideal, are we as clinicians not responsible forreplicatingtheideal,shouldadverseconditionsir- revocably alter nature and necessitate its elimina- tion? Nature wisely created a structure that could har- moniouslyinterpolatehardandsofttissue,actasthe portal of nutrition and communication for the body, and be the gatekeeper on guard and in function throughoutourlifetime.Ourroleistoensurethatwe re-engineer nature; we must adhere to its rules, its logicandfundamentals.Thisisnotaneasytask,asfil- tering out the best range of evidence from a wide range of sources, presenting clear, comprehensive analyses and incorporating patient experience is a Herculean task. In many ways, this is analogous to Alice’sAdventuresinWonderland,assomuchofwhat wedogrowscuriouserandcuriouseraseachnewin- novation demands that we go through the looking glassanddeterminewhatAlicefoundthere._ “There’s no use trying,” said Alice. “One can’t believe impossiblethings.”“Idaresayyouhaven’thadmuch practice,”saidtheQueen.“WhenIwasyourage,Ial- ways did it for half an hour a day. Why, sometimes I’vebelievedasmanyassiximpossiblethingsbefore breakfast.” —Lewis Carroll Editorial note: A complete list of references is available fromthepublisher. Fig. 11c_The Morse taper connec- tion of the Ankylos C/X (internal index) fixture distributes oblique and horizontally applied forces over a large area of the matrix joining surface inside the implant. The connection is therefore only loaded in the vertical direction. The cross- section shows no gap between the abutment taper and the implant which avoids micro-loosening. This is in contrast to systems with internal hex connections (clearance fit) that demonstrate micro-motion and ‘rotational slop’, making them prone to inflammatory reactions at the implant-abutment connection due to micro-leakage. Fig. 12a_The platform-switched design negates micro-motion and resultant crestal bone resorption. The goal of ortho-biological replacement is the idealised replication of the natural state. Fig. 12b_The expectation of a precise cone fixture-abutment connection is that the crestal bone will overgrow the fixture platform and remain in that position regardless of whether the implant was placed in a grafted site or immediately placed in an extraction site. Die-back or saucerisation is not a consideration. I 17implants2_2011 Fig. 12b Dr Kenneth Serota 4310 Sherwoodtowne Blvd. Suite 300 Mississauga,Ontario L4Z 4C4 Canada kendo@endosolns.com www.endosolns.com | www.rxroots.com | www.ankylosworld.com _contact implants