16 May 2022

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Primary Molars Restorations: Flowable Bulk-fill Materials VS Nano Ceramic Composites

Lara Figini

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One of the most common materials for the restoration of primary teeth are glass ionomer cements (GIC), because of their time-saving feature. Nonetheless their mechanical properties aren’t good enough to guarantee long-term restorations.
The bulk-fill resin based composite (RBC) seem to be an efficient alternative to the GIC for pediatric dentistry, in particular the flowable one. In fact this material can speed-up the restorative treatment by skipping the time-consuming layering process without adverse effects. The flowable bulk-fill composite can be directly applied after cavity preparation, but according to the manufacturer instructions, it can’t replace any regular nanohybrid and microhybrid RBCs in the occlusal part. In fact elasticity and hardness of bulk-fill RBC materials are significantly inferior.   The aim of this split-mouth study, published on Dentistry Journal in 2019 was to compare the performance of primary molar class I cavities restorations with bulk-fill RBC compared with a nanoceramic composite in a period of 24 months.  

Matherials&Methods
27 children with at least two class I cavities in primary molars were enrolled for the study. Cavities were prepared with turbine burs; treatment of tooth surface was performed with the selective etching of enamel with 37% phosphoric acid and application of the bonding agent after the disinfection of cavities with 1% chlorhexidine.  54 restorative interventions were carried out- 27 with flowable bulk-fill composite and 27 with nano ceramic composite- and then evaluated three times during the 24-month period (at 6, 18, and 24 months) according to the modified Ryge criteria. The cavosurface marginal discoloration was evaluated visually after air-drying the tooth and after plaque removing.  

Results 
The evaluation after 24 months registered similar clinical results for all the 54 restorations. Statistical analysis showed not significant differences between the two tehniques. However, two restorations in both groups received Bravo ratings in the cavosurface marginal discoloration scoring.

Conclusions
After 24 months the two matherials showed good and similar clinical performances, however the study had a too small sample to have a strong scientific evidence. As the two technique provides identical results, the easier and faster application technique of bulk-fill material can be very helpful in pediatric dentistry.   

For additional informations: Flowable Bulk-Fill Materials Compared to Nano Ceramic Composites for Class I Cavities Restorations in Primary Molars: A Two-Year Prospective Case-Control Study