Interventions for replacing missing teeth: different times for loading dental implants

Background To minimize the risk of implant failure, osseointegrated dental implants are conventionally kept load-free during the healing period. During healing removable prostheses are used, however many patients find these temporary prostheses rather uncomfortable and it would be beneficial if the healing period could be shortened without jeopardizing implant success. Nowadays immediately and early loaded implants are commonly used in mandibles (lower jaws) of good bone quality. It would be useful to know whether there is a difference in success rates between immediately or early loaded implants compared with conventionally loaded implants. Objectives To test the null hypothesis of no difference in the clinical performance between osseointegrated implants loaded at different times 6 months to 1 year after loading. Search strategy The Cochrane Oral Health Group's Trials Register, The Cochrane Central Register of Controlled Trials, MEDLINE and EMBASE were searched. Handsearching included several dental journals. Authors of all identified trials, an internet discussion group and 55 dental implant manufacturers were contacted to find unpublished randomised controlled trials (RCTs). The last electronic search was conducted on 7 August 2006. Selection criteria All RCTs of root-form osseointegrated oral implants having a follow up of 6 months to 1 year comparing the same osseointegrated root-form oral implants immediately (within 1 week); early (between 1 week to 2 months); and conventionally loaded (after 2 months). Outcome measures were: prosthesis failures, implant failures and marginal bone levels on intraoral radiographs. Data collection and analysis Data were independently extracted, in duplicate, by two review authors. Authors were contacted for details of randomisation and withdrawals and a quality assessment was carried out. The Cochrane Oral Health Group's statistical guidelines were followed. Main results Twenty RCT; were identified and 11 trials including 300 patients in total were included. Six trials compared immediate versus conventional loading, three early versus conventional loading and two immediate versus early loading. On a patient, rather than per implant basis, there were no statistically significant differences for any of the meta-analyses. Authors' conclusions It is possible to successfully load dental implants immediately or early after their placement in selected patients, though not all clinicians may achieve optimal results when loading the implant immediately. A high degree of primary implant stability (high value of insertion torque) seems to be one of the prerequisites for a successful immediate/early loading procedure. More well designed RCTs are needed. Priority should be given to trials comparing immediately versus early loaded implants to improve patient satisfaction and decrease treatment time. These trials should be reported according to the CONSORT guidelines (http://www.consort-statement.org/).