Comparative evaluation of effect of three different crown to implant ratio on marginal bone loss: A systematic review

Partial rehabilitation in the posterior edentulous region remains a challenge due to the anatomical condition present in the area. Excessive pneumatization of the maxillary sinus and accentuated bone crest resorption following teeth extraction cause bone atrophy and may lead to impossibility of inserting standard implants. Constant efforts are aiming at the reduction of the invasiveness of implant surgery. This has led to increase the use of implants with shorter length in the posterior maxilla and mandible region which reduces the need for additional surgical procedure causing less morbidity of the site and faster healing of the region. Does crown to implant ratio has an effect on the marginal bone loss (MBL) around implants in the posterior maxillary and mandibular region? A systematic search was conducted on two databases for the studies published from January 1, 2006, to July 31, 2018. Cross-references were checked. Hand searching was done in the library. Studies were included if they were done among healthy, nonhospitalized individual, and compared for the crown-to-implant ratio and MBL. A total of 143 articles were found through search. Thirteen articles remained after removing duplicates, reading the full text and reviewing abstracts. Thirteen articles were included for the data extraction. Crown-to-implant ratio has no role in the crestal bone loss, but other factors need to be evaluated for its role along with crown-to-implant ratio that can cause the MBL.