Current Evidence on the Socket-Shield Technique: A Systematic Review

The recently popularized socket-shield technique involves intentional retention of a section of the remnant root at the time of immediate implant placement, thereby preserving the buccal/proximal bone from resorption. The objective of this systematic review was to assess the literature available on the socket-shield technique and weigh its biological plausibility and long-term clinical prognosis. A systematic search was performed on PubMed-Medline, Embase, Web of Knowledge, Google Scholar, and Cochrane Central for clinical/animal studies from January 1970 to April 2017. Twenty-three studies were assessed: 1 clinical case-control study, 4 animal histological reports, 1 clinical abstract, and 17+2* case reports. Eighteen out of the 23 studies had a duration of ≤12 months. A quality assessment of 5 studies (4 animal histologic and 1 clinical case-control) performed using the modified Animal Research: Reporting of In Vivo Experiments guidelines revealed that 4/5 studies had low scores. Fifty-eight out of 70 (82.86%) implants from 4 animal histological studies had complications; buccal/crestal bone loss (54.55%) and failure of osseointegration (27.27%) were the most common. Thirty-three out of 136 (24.26%) implants from 19+2 (2 studies had both histologic and clinical components, which are assessed separately) clinical studies had complications; buccal/crestal bone loss (78.78%) and shield exposure/failure (12.12%) were the most common. Other complications recorded were periodontal ligament and cementum formation on implant surfaces, pocket formation, inflammation, mucositis, and peri-implantitis. However, some clinical reports indicated stable results at 12 months. It would be difficult to predict the long-term success of this technique until high-quality evidence becomes available. A video abstract is available for viewing at https://youtu.be/lNMeUxj2XPA?list=PLvRxNhB9EJqbqjcYMbwKbwi8Xpbb0YuHI .