Functionalized pink Al 2 O 3 :Mn pigments applied in prosthetic dentistry

Abstract

Statement of problem The color of dental polymethyl methacrylate (PMMA) is traditionally rendered by organic and inorganic pigments, which are usually not bonded to the polymer network. Functionalized ceramic pigments can be used to color PMMA allowing improved chemical interaction with the resin matrix. Purpose The purpose of this in vitro study was to synthesize, functionalize, and characterize pink manganese-doped alumina ceramic pigments. The hypothesis tested was that functionalized ceramic pigments would render pink coloration to a translucent PMMA without jeopardizing its mechanical properties. Material and methods Pink alumina powders doped with 1 mol% or 2 mol% of manganese (Al2O3:Mn) were prepared by means of a polymeric precursor method. Pigment particles were functionalized with a silica coating method followed by silanation before preparation of PMMA-based composite resins (5 wt% pigment). The color of composite resins (Pig.1% and Pig.2%) and PMMA controls (Pink and Translucent) was evaluated (CIELAB color coordinates), and their mechanical properties were tested (3-point-bending). Results The microstructure of the pigment particles showed approximately 55-nm nanocrystals of manganese-doped α-alumina clustered into irregular porous particles up to 60 μm. The composite resins and Pink PMMA showed similar color parameters (CIE a* Pink=20.1, Pig.1%=14.6, Pig.2%=16.0, Trans=0.19 – P<.001; CIE b* Pink=17.0, Pig.1%=18.6, Pig.2%=19.0, Trans=2.52 – P<.001). No statistical differences were observed in mechanical properties among groups (σf Pink=98.4, Pig.1%=98.1, Pig.2%=98.8, Trans=89.1 – P=.136). Conclusions The addition of the functionalized pink ceramic pigments to a translucent PMMA yielded similar coloration to that of the regular pink PMMA used in dentistry and did not jeopardize its mechanical properties.

Polymeric Denture Base Materials: A Review

“…Denture base resins contain mostly iron oxides or titanium oxides as pink pigments. Adding these pigments to a PMMA yielded similar coloration to that of the regular pink PMMA used in dentistry and did not jeopardize its mechanical properties [ 119 , 120 , 121 ].…”