Influence of interimplant distance on the crestal bone height around dental implants: A systematic review and meta-analysis

Statement of problem. Indexed publications lack a systematic review and meta-analysis of the influence of interimplant distance on the interproximal crestal bone height (ICBH) around implants. Purpose. The purpose of this systematic review and meta-analysis was to assess the influence of interimplant distance on ICBH around implants. Material and methods. The question addressed was, "Does interimplant distance influence the ICBH around implants?" Indexed databases from 1978 up to April 2015 were searched by using the keywords "crestal bone level", "bone loss", "bone height", and "interimplant distance." Reference lists of potentially relevant original and review articles were searched manually to identify any unidentified studies. Articles available online in electronic form ahead of print were eligible for inclusion. Letters to the Editor, case reports, case series, commentaries, studies involving bone augmentation procedures, and studies published in languages other than English were excluded. A meta-analysis of mean differences in ICBH among study groups was also performed. Results. In total, 5 animal studies with relatively short follow-up periods (2-12 months) were included. Results from 4 studies showed no significant differences in ICBH around implants placed 1 to 3 mm apart. However, 1 of the 5 studies found that vertical bone loss was significantly lower in implants that had an interimplant distance of 5 mm than those placed at a distance of 1 mm. Platform switched and rough surface implants were used in all studies. Conclusions. The influence of interimplant distance on ICBH around dental implants remains unclear.