IADR Abstract Archives
Evaluation of the Porcine Model for Molar-Incisor-Hypomineralization (MIH) Treatment Strategies
Objectives: Extracted human MIH-teeth for in vitro tests are rare and there is no classic animal model for MIH. Therefore, this study aims to evaluate through ex vivo studies porcine enamel as a model for human MIH-affected enamel.
Methods: The key characteristics of MIH-affected human enamel were compiled through literature research.
Teeth were obtained from pigs raised under controlled conditions. Porosity of deciduous porcine enamel (n=5 teeth, 13 weeks-old pig) was explored by fluorescein penetration and confocal laser scanning microscopy (CLSM). Resin-embedded teeth were sectioned longitudinally, polished and analyzed for microhardness from cervical to cuspal in 500µm steps with 6 indentations/site (Veeco Microhardness tester) then for microstructure (scanning electron microscopy (SEM)). Western Blot was used to validate albumin presence in micro-sampled porcine enamel. Albumin distribution was visualized by fluorescent labelling and CLSM on enamel cross-sections (primary antibody: Anti-Pig Albumin, ab79960, Abcam; secondary antibody: Donkey Anti-Rabbit IgG NorthernLights NL637, R&D Systems). Finally, a risk-benefit-assessment for using porcine enamel as a model for MIH-enamel was performed.
Results: MIH-affected enamel is characterized by substantially impaired mechanical and chemical properties. The high protein content, especially albumin, blocks pathways for mineral-diffusion and inhibits crystal growth.
Our results from fluorescein penetration and SEM analyses show retained organic matter and perforations in porcine enamel. Surface porosity decreases with post-eruptive time, while microhardness values [HV] increase from 61 (+/-38) to 400 (+/-17), covering the range of human MIH-enamel. Western blot-analysis confirmed the presence of albumin, consistent with reports on human MIH-enamel. Fluorescently labeled albumin was evenly distributed throughout the porcine enamel thickness.
Conclusions: As removal of albumin appears to be a critical intervention in human MIH treatment, the unique presence of albumin and appropriate structural and mechanical characteristics of deciduous porcine enamel make the porcine model a valuable approximation and test case for MIH-affected human enamel.
Methods: The key characteristics of MIH-affected human enamel were compiled through literature research.
Teeth were obtained from pigs raised under controlled conditions. Porosity of deciduous porcine enamel (n=5 teeth, 13 weeks-old pig) was explored by fluorescein penetration and confocal laser scanning microscopy (CLSM). Resin-embedded teeth were sectioned longitudinally, polished and analyzed for microhardness from cervical to cuspal in 500µm steps with 6 indentations/site (Veeco Microhardness tester) then for microstructure (scanning electron microscopy (SEM)). Western Blot was used to validate albumin presence in micro-sampled porcine enamel. Albumin distribution was visualized by fluorescent labelling and CLSM on enamel cross-sections (primary antibody: Anti-Pig Albumin, ab79960, Abcam; secondary antibody: Donkey Anti-Rabbit IgG NorthernLights NL637, R&D Systems). Finally, a risk-benefit-assessment for using porcine enamel as a model for MIH-enamel was performed.
Results: MIH-affected enamel is characterized by substantially impaired mechanical and chemical properties. The high protein content, especially albumin, blocks pathways for mineral-diffusion and inhibits crystal growth.
Our results from fluorescein penetration and SEM analyses show retained organic matter and perforations in porcine enamel. Surface porosity decreases with post-eruptive time, while microhardness values [HV] increase from 61 (+/-38) to 400 (+/-17), covering the range of human MIH-enamel. Western blot-analysis confirmed the presence of albumin, consistent with reports on human MIH-enamel. Fluorescently labeled albumin was evenly distributed throughout the porcine enamel thickness.
Conclusions: As removal of albumin appears to be a critical intervention in human MIH treatment, the unique presence of albumin and appropriate structural and mechanical characteristics of deciduous porcine enamel make the porcine model a valuable approximation and test case for MIH-affected human enamel.