Conventional and early loading of two-implant supported mandibular overdentures. A systematic review

Implant loading time is considered to influence the treatment outcomes. Number of experimental studies have shown that implant loading up to 3 months can produce equally satisfactory results. However, research results in this area are not consistent. The purpose of the study was to investigate the influence of conventional and early loading of two-implant supported mandibular overdentures on treatment outcomes.

The articles from 1985 to 2007 in English related to the topic were identified. Totally 221 (214 online and 7 printed) primary articles were detected. Eight articles were selected for data extraction. Implant survival and success rates, periimplant parameters, prosthetic maintenance and patient satisfaction were considered.

Implant success rate ranged from 83% to 100% in conventional loading group and from 71% to 100% in early loading group. During the first year in conventional group, the marginal bone loss ranged from 0.35 to 0.91 mm, during the second year--from zero to 0.2 mm, whereas in early loading group these intervals were 0.12-1 mm and 0-0.15 mm, respectively. Comparing averaged probing depth values at different time periods, it could be noticed that around conventionally loaded implants probing depth slightly decreased (from 1.62 mm to 1.56 mm), while around early loaded implants--increased from 1.7 mm to 1.82 mm.

Considering implant success rates and peri-implant parameters early loading protocol produces equal outcomes as with conventional loading. More well designed studies are needed to further substantiate the early loading protocol.