Survival of directly placed ormocer-based restorative materials: A systematic review and meta-analysis of clinical trials

- Ormocers demonstrated no difference in success compared to conventional composites.
- Although non-significant, the global failures was higher for ormocers.
- A significantly higher failure rate due to sensitivity was observed for ormocer-based materials than for other composites.
- Methodological quality should be improved, using CONSORT and Cochrane guidelines.
- Future RCT should test a new family of ormocers, dimethacrylate-diluent-free.

ObjectivesIn-vitro experiments on ormocers (ORganically MOdified CERamics) have provided controversial results. Consequently, the objectives of this meta-analysis were to (1) compare clinical performances of first generation ormocers versus conventional composite restorations, (2) explore the influence of various clinical factors and the impact of the quality of studies on published results.MethodsThe following databases were explored until 2017/01/08: Ovid MEDLINE In-Process, Pubmed, CENTRAL, HTA, DARE, LILACS and Google Scholar.Studies of more than two years with quantitative comparisons between ormocers and control groups were selected. Outcome was the failure of a restoration (need to repair, remove or replace). Multivariate random-effects Poisson's regression was used to obtain a summary estimate.Results75% of the 8 included trials concerned Class I/II restorations. Although non-significant, the global failures were higher for ormocers (0.22 [−0.16; 0.61]). For Class I/II restorations, a significantly higher sensitivity was observed for ormocer-based materials compared to other composites (0.75 [0.01; 1.50]). An increase of the number of restorations per patient was associated with higher marginal adaptation failures for ormocers in Class I/II obturations (0.59 [0.11; 1.08]).SignificanceThis study did not identify clear advantages of using the first generation of ormocer-based fillings rather than conventional composites. Given the recent development of new, dimethacrylate-diluent-free ormocer matrices, potentially more stable and resistant, new randomized clinical trials should be developed comparing this new family of pure ormocers with current composites.