The impact of endodontic access on the biaxial flexure strength of dentine-bonded crown substrates - anin vitrostudy

AIM To investigate how preparation of a simulated access cavity into ceramic materials suitable for the manufacture of dentine-bonded crowns (DBCs) impacted on biaxial flexural strength (BFS) determined as a monolithic structure and in a more clinically representative resin-cemented form. METHODOLOGY One hundred and twenty feldspathic and 120 leucite-reinforced ceramic disc-shaped specimens were divided into eight groups (n = 30). All groups received 'fit' surface treatments representative of pre-cementation modifications and of cementation prior to preparation of a representative endodontic access cavity through the sample. BFS was determined for both 'intact' and the 'annular' disc-shaped specimens which had received simulated endodontic access. Newly reported analytical solutions were used to calculate BFS of the 'annular' specimens. Statistical analysis included two-way anovas (α = 0.05) and Weibull analysis. Fractographic examination provided insight into the fracture mechanisms. RESULTS A two-way anova identified a significant impact of material (P