A range of regenerative treatments have been used for the  treatment of periodontal infrabony defects. Guided tissue regeneration (GTR) and enamel matrix derivatives (EMD) are two popular treatment and they have both been used in combination with other treatment.   This network meta-analysis was conducted to assess the potential effects of the various combinations. Unlike a traditional meta-analysis, which summarize the results of trials that have evaluated the same treatment/placebo combination,  a network meta-analyses  allows comparison of the results from two or more studies that have one treatment in common, allowing indirect comparisons of treatments.  While a useful approach it is potentially more subject to error than a routine meta-analysis.

A systematic search of  the Medline, Embase, LILACS and Cochrane Central Register of Controlled Trials (CENTRAL) databases was undertaken. Randomised studies with  treatment outcomes measured at baseline and at least 12 months after the treatments were included. Studies that included lesions with infrabony defects < 3mm were excluded. Treatment outcomes were changes in probing pocket depth (PPD), clinical attachment level (CAL) and infrabony defect depth.

The authors included 53 studies and found

• Small differences between regenerative therapies which were non-significant statistically and clinically
• GTR and GTR-related combination therapies achieved greater PPD reduction than EMD and EMD-related combination therapies.
• Combination therapies achieved slightly greater CAL gain than the use of EMD or GTR alone.
• GTR with BG achieved greatest defect fill.

They concluded

Combination therapies performed better than single therapies, but the additional benefits were small. Bayesian network meta-analysis is a promising technique to compare multiple treatments. Further analysis of methodological characteristics will be required prior to clinical recommendations.

Tu Y-K, Needleman I, Chambrone L, Lu H-K, Faggion CM Jr. A bayesian network meta-analysis on comparisons of enamel matrix derivatives, guided tissue regeneration and their combination therapies. J Clin Periodontol 2012; doi: 10.1111/j.1600-051X.2011.01844.x.

Related Cochrane Reviews

Needleman, I., Worthington, H. V., Giedrys-Leeper,E. & Tucker, R. (2006) Guided tissue regeneration for periodontal infra-bony defects. Cochrane Database of Systematic Reviews. Art. No.: CD001724, doi:10.1002/14651858.CD001724.pub2.

Esposito, M., Grusovin, M. G., Papanikolaou, N., Coulthard, P. & Worthington, H. V. (2009) Enamel matrix derivative (Emdogain®) for periodontal tissue regeneration in intrabony defects. Cochrane Database of Systematic Reviews. 2009. Art. No.: CD003875, doi:10. 1002/14651858.CD003875.pub3.