Does an intracanal composite anchorage replace posts?

OBJECTIVES: This study aims to assess the effectiveness of an intracanal composite anchorage to replace conventionally cemented titanium or bonded glass fibre posts. MATERIALS AND METHODS: Post space preparation was performed up to depths of 6 mm (groups 1 and 2) and 3 mm (group 3) in root filled mandibular premolars. In group 1, titanium posts were cemented with zinc phosphate cement. Glass fibre posts were adhesively cemented in group 2 using a dual-cure composite resin. In group 3, intracanal anchorage was solely performed with a dual-cure composite. All teeth were restored with standardised direct composite crowns without a ferrule. After thermo-mechanical loading, static load was applied until failure. Fracture patterns were assessed, and a microscopic analysis was performed to analyse the occurrence of additional cracks. RESULTS: Group 2 revealed a significantly higher median fracture value (408 N) than groups 1 and 3, while no difference was detected between group 1 (290 N) and group 3 (234 N) (p = .1417). In group 3, the more favourable fracture patterns were observed. However, the majority of teeth within this fracture category revealed additional minor cracks of the root. CONCLUSIONS: Within the limitations of this study, adhesive intracanal anchorage to a depth of 3 mm with resin composite only has the same fracture resistance as titanium posts conventionally cemented to a depth of 6 mm. Even teeth with repairable main fractures exhibited additional dentinal cracks on the root. CLINICAL RELEVANCE: Additional dentinal root cracks in the teeth with repairable main fractures may considerably impair their longevity.