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Interventions for replacing missing teeth: bone augmentation techniques for dental implant treatment.

BACKGROUND
Dental implants require sufficient bone to adequately stabilise. For some patients implant treatment would not be an option without bone augmentation. A variety of materials and surgical techniques are available for use in bone augmentation.


OBJECTIVES
To test the null hypothesis of no difference in the success, function, morbidity and patient satisfaction between different bone augmentation techniques for dental implant treatment.


SEARCH STRATEGY
The Cochrane Oral Health Group's Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE and EMBASE were searched. Several dental journals were handsearched. The bibliographies of review articles were checked, and personal references were searched. Implant manufacturing companies were also contacted.


SELECTION CRITERIA
Randomised controlled trials (RCTs) of different techniques and materials for augmenting bone for implant treatment.


DATA COLLECTION AND ANALYSIS
Quality assessment was carried out and authors were contacted for any missing information. Data were independently extracted in duplicate.


MAIN RESULTS
Four RCTs (n = 95) were suitable for inclusion in this review, assessing three different aspects of bone augmentation techniques: onlay grafting with and without a barrier membrane, grafting with a resorbable and non-resorbable membrane, and membranes for guided bone regeneration (GBR). Trials reported on augmentation procedures up to abutment connection only. At the patient level there were no statistically significant differences for the alternative techniques for onlay grafting with respect to the degree of bone graft resorption and wound dehiscence. One trial showed statistically significantly more infections in the non-resorbable group compared to the resorbable group, relative risk 0.05 (95% confidence interval (CI): 0.00 to 0.74). One study of GBR with a resorbable versus non-resorbable membrane indicated no statistically significant difference in early implant failure, reduction in bone defect or wound dehiscence. The other GBR study compared a non-resorbable membrane with no membrane and reported no statistically significant difference in wound infection or dehiscence but a significant increase in per cent bone gain for the test group compared to control, mean difference = 70 (95% CI: 36 to 104, p = 0.002).


REVIEWER'S CONCLUSIONS
There is no evidence from available RCTs supporting superior success with one or other of the alternative techniques examined. There was weak evidence that a non-resorbable membrane was better than no membrane for permitting bone growth about dental implants, and that a resorbable membrane over a bone graft may allow healing with fewer infections than a non-resorbable membrane.