Survival of Endosseous Implant

Survival of endosseous implant is highly depended on the integration between the implant surface and the oral tissue which includes both hard and soft tissues.The first and foremost sign of lost breakdown at the implant tissue interface is generally seen at crestal region. Therefore, the crestal bone loss around the implant plays a very vehicle role in determining the success of osseointegrated implant. The earlier implant crestal bone loss during healing and consequently following the first year of function is often greater during initial stage.

Various studies and literature references have demonstrated that stress concentrated around the crestal region during/after prosthetic loading. It is observed that the density of the alveolar bone housing may influence the early bone loss around implants. Weber et al studies showed that low density bone had more bone loss.

According to Cook et al evaluation there is a correlation between labial plate thickness and thin or thick gingival biotypes. Various studies demonstrated that mucosal thickness and biologic width affect crestal bone loss around implants. It is also noticed that the dimension and position of biological width formed around the implant surfaces during early phase of healing may influence the degree of implant crest module design plays a very crucial role in the formation of biologic seal around the implant surface.

Platform-switching is a method used to improve the biological seal and also preserve the crestal bone level around an implant.The concept of platform switching was introduced by Lazzara and Porter in 2006. Lazzara et al have hypothesized that shifting the implant-abutment junction (IAJ) inward also shifts the inflammatory cell infiltrate inward and away from the crestal bone. Because of horizontal inward movement of implant-abutment union thickens the connective tissue laterally, which increases blood flow around that area. So a biological seal establish around dental implants, these changes protect the crestal bone.

Regarding biomechanical advantages in the use of platform switching, unlike conventional implants where a high stress area around implant’s neck and along its lateral surface, but in the platform switching the stress is distributed inwards towards the central axis thus improving the distribution of forces and reduces crestal marginal bone loss after loading.

Berglundh and Lindhe in 1996 in their animal studies showed that a particular width thickness is necessary required to establish biologic width around dental implant as well as they said that if less thickness is present, crestal bone resorption will occur upto enough space is establish for both connective tissue and junctional epithelium. Formation of the biologic width around an implant is influenced by the gingival biotype. The gingival biotype contributes significantly to the marginal bone stability around dentition/implant.

Becker W et al in 1997 studies shown that thin biotype associated with fenestrations and bony dehiscences. According to Wagenberg B et al and Tabata et al at 2010 the gingival biotype, the distance of the implant-abutment junction(IAJ) from the bone crest, repositioning of the gingival inflammatory infiltrate, and the distribution of the forces in the portion of the implant in contact with the cortical bone are the factors that plays a major role in the changes of bone height.

Linkevicius studies demonstrated that implants with thin crestal mucosa more prone to higher marginal crestal bone loss. In the present study platform switched endosseous implants were placed in patients with different gingival biotype and to evaluate hard and soft tissue changes that occur around the dental implant over a period of one year.