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Microtomographic Analysis of Resin Composite Core Material Porosity
Author(s) -
Roberts Howard,
Fuentealba Rodrigo,
Brewster John
Publication year - 2020
Publication title -
journal of prosthodontics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.902
H-Index - 60
eISSN - 1532-849X
pISSN - 1059-941X
DOI - 10.1111/jopr.13167
Subject(s) - materials science , porosity , composite material , core (optical fiber) , composite number
Purpose To nondestructively evaluate the porosity of ten contemporary resin composite core materials using microtomographic (microCT) analysis. Material and methods Resin composite core material samples (n = 12) including dual‐cure, visible light cure only, and a self‐cure material were fabricated using a standardized mold following manufacturer's recommendations. After storage in phosphate buffered saline for one week, specimens were analyzed using a microCT unit at 5.3‐µm resolution over a rotational range of 360°. Image 3D recombination and analysis was accomplished using microCT software. Evaluated parameters included material volume investigated, closed pore number and volume, as well as closed pore percentage. Parameter mean values were evaluated with Kruskal‐Wallis/Dunn at a 95% confidence level (α = 0.05). Results Mean percent total porosity with standard deviation identified significant differences in decreasing order as Ti‐Core: 2.2 (0.4) > Ti‐Core Auto E: 1.3 (0.3) = Ti‐Core Flow Plus: 1.1 (0.02) > Clearfil Photo Core: 0.94 (0.5) = Clearfil DC Core Plus: 0.6 (0.18) = MultiCore Flow: 0.58 (0.1) > Fluorocore 2+: 0.14 (0.2) = Build‐It FR: 0.068 (0.02) = Gradia Core: 0.03 (0.02) = Rebilda DC: 0.02 (0.01). A pilot microCT evaluation evaluating a mixing tip revealed incomplete mixture between the two resins with porosity introduced from turbulence as the materials are forced through the tip during preparation. Conclusions A wide range of porosity was identified between the ten materials evaluated. These preliminary results warrant more investigation evaluating additional resin composite core materials, the preparation capabilities of automix tips, and porosity presence in the unmixed materials.