Dental Tribune United Kingdom Edition

May23-29, 2011United Kingdom Edition22Implant Tribune page 21DTß About the author Dr Virgil Koszegi Stoianov Msc Office: Str.Paciurea No. 5 300036 Timisoara, Romania Tel.: +40 356433733 Mobile: +40 723573443 E-mail: virgil.koszegi@medicis.ro the stress concentration away from the cervical bone-implant interface.51 Generally, the horizontal component created by platform switching is around 0.5mm (Fig. 6), sufficient to result in significantly less radiological detectable crestal bone loss in humans.51, 52 Not only does this concept reduce the risk of peri-implantitis in the future but also has the benefit in the aesthetic zone of providing better soft tissue support.53 Implant-tooth or inter-im- plant distance For single tooth dental im- plants, a minimum horizon- tal distance of 1.5mm must be left between the implant and the two approximating tooth root surfaces in order to avoid crestal bone loss after biologic width accommodation. When two implants are placed side by side, the crestal bone loss that occurs between them has a more complicated aetiology. First and foremost, inter- implant crestal bone loss will be affected by the horizontal distance between the two im- plants which should be mini- mum 3mm (Fig. 7). It will also be influenced by the level of micro-gap, biologic width, and whether platform switching was used or not. A clear tendency for in- creased inter-implant vertical bone loss occurs as the dis- tance between two implants decreases below 3mm.54, 55 Histological data from animal experiments using 2—piece, moderately rough surface, submerged implants, showed that vertical inter- implant bone loss decreased from 1.98mm for a 2mm inter-implant distance to 0.23mm for 5mm inter-implant distance.56 Conclusion Significant differences in mar- ginal bone loss have been iden- tified between implants with platform switching and im- plants without platform switch- ing only in the first year after loading. It may be concluded that the platform switching concept represents a bone preserving technique. Preser- vation of crestal bone around dental implants cannot be attributed to a single param- eter. That is the result of a number of important factors, especially in the challenging aesthetic zone. It is important to under- stand the mechanism that permits the implant-abutment connection to maintain a seal against the bacterial ingress before and after loading due to absence of micromove- ments. An appropriate under- standing of the importance of biologic width and the use of platform switching concept in the routine treatment is of real support in maintaining a more stable marginal bone level around implants. This stable marginal bone as a support of the soft tissue is determinant for the long- term aesthetic stability. Fur- ther neutral clinical studies are required to demonstrate the importance of micro-gap, biologic width and platform- switching in crestal bone preservation around dental implants. For the support I thank: Dr Mazen Tamimi, Private Prac- tice, Amman, Jordan, Dr Rain- er Valentin, Private practice, Cologne, Germany, Dr R. & M. Vollmer, Private practices, Wissen, Germany DT Editorial note: The literature list can be requested from the author. ‘When two implants are placed side by side, the crestal bone loss that oc- curs between them has a more compli- cated aetiology’