Effects of adhesive composite core systems on adaptation of adhesive post and cores under load

ObjectivesTo test marginal and internal adaptation of five different adhesive composite core systems under load.Methods30 human premolars were endodontically prepared and obturated with an epoxy sealer and vertically condensed gutta-percha. Thereafter the entire clinical crown was removed. The teeth were randomly assigned to five different composite core groups, all using the same fiber reinforced radicular post (DT White). Gr. 1: Optibond solo plus/Nexus II/Prodigy; Gr. 2: Scotchbond 1/Rely X Arc/Filtek P60; Gr. 3: EBS multi/Compolute applicap/Pertac II; Gr. 4: ART Bond/Parapost cement/Synergy; Gr. 5: Superbond C&B catalyst S + polymer/Metafil CX. Polyvinyl-siloxane impressions of the external margins of the cores were readied before and after 1,200,000 cycles of mechanical loading with max. 100 N at 45° to the longitudinal axis of the tooth. After loading, 5 of the 6 samples of each group were cut longitudinally and the sixth sample was cut transversally to be able to take replicas for evaluation of internal adaptation after loading.ResultsPercentages of external “continuous margins” ranged from 97.9 + −4.6 to 66.5 + −7.8 before and from 87.4 + −25.0 to 5.8 + −12.5 after loading. Internal adaptation ranged from 96.4 + −8.0 to 17.1 + −20.4 after loading for the core adaptation and from 89.8 + −12.2 to 65.9 + −14.3 for the dentin–luting composite interface and from 99.4 + −1.2 to 88.6 + −9.4 for the composite-post interface.ConclusionsSurprisingly, the best materials’ combination for the adhesive composite core was a self-etch light cured adhesive with a chemically cured luting agent.