Nina Lümkemann1, Marlis Eichberger1, Bogna Stawarczyk2. 1. Department of Prosthodontics, Dental School, Ludwig-Maximilians University Munich, Goethestrasse 70, 80336 Munich, Germany. 2. Department of Prosthodontics, Dental School, Ludwig-Maximilians University Munich, Goethestrasse 70, 80336 Munich, Germany. Electronic address: Bogna.stawarczyk@med.uni-muenchen.de.
Abstract
OBJECTIVES: To assess the impact of irradiation on Martens hardness parameters of different PEEK qualities filled with titanium dioxide (TiO2), namely PEEK/0%, PEEK/20%, and PEEK/>30%. METHODS: For Martens hardness (HM) measurements, 40 specimens of each PEEK quality were fabricated and air-abraded with 50μm Al2O3. HM parameters of PEEK specimens were measured initially and stepwise after irradiating for 5, 10, 20, 30, 40, 60, 80, 100, 180, 360 and 540s using light units with different wavelength: Elipar S10 (430-480nm), EyeVolutionMAX (385-390nm+465-470nm), Translux CL (380-500nm) and bre.Lux Power Unit (370-500nm). HM parameters of 10 human teeth were measured initially on enamel and dentin. Data was analysed using 3-way ANOVA with partial eta-squared (ηP2) and post-hoc Tuckey-HSD-test (p<0.05). RESULTS: PEEK qualities followed by the wavelength showed the highest effect on Martens hardness (p<0.013). PEEK/>30% (197.35±19.9N/mm2), followed by PEEK/20% (191.45±15.49 N/mm2) showed significantly higher values for HM than PEEK/0% (189.55±16.89N/mm2). PEEK/>30% (5.49±0.4kN/mm) and PEEK/20% (5.38±0.26kN/mm2) presented higher indentation modulus (EIT) than PEEK/0% (4.77±0.36kN/mm2). Irradiated with wavelength of 430-480nm (PEEK/0%: 193.28N/mm2, PEEK20%: 198.83N/mm2, PEEK/>30%: 200.5N/mm2) indicated higher HM compared to specimens irradiated with 380-500nm (PEEK/0%: 186.63N/mm2, PEEK20%: 191.05N/mm2, PEEK/>30%: 196.13N/mm2). Irradiation using 430-480nm (PEEK/0%: 4.95kN/mm2, PEEK20%: 5.52kN/mm2, PEEK/>30%: 5.59kN/mm2) and 370-500nm (PEEK/0%: 4.92kN/mm2, PEEK20%: 5.43kN/mm2, PEEK/>30%: 5.53kN/mm2) indicated higher EIT values compared to specimens irradiated with 380-500nm (PEEK/0%: 4.72kN/mm2, PEEK20%: 5.34kN/mm2, PEEK/>30%: 5.47kN/mm2). Duration of irradiation presented no impact on results. Enamel (HM: 2263.6±405.16, EIT: 63.16±19.24) and dentin (HM: 468.2±30.77N/mm2, EIT: 14.14±4.59kN/mm2) presented significantly higher HM and EIT than the tested PEEK qualities (p<0.001). SIGNIFICANCE: Irradiation with different wavelength impacted HM parameter. The increase of TiO2 percentage in PEEK matrix improved the HM parameter. However, PEEK showed significantly lower HM parameter than human teeth.
OBJECTIVES: To assess the impact of irradiation on Martens hardness parameters of different PEEK qualities filled with titanium dioxide (TiO2), namely PEEK/0%, PEEK/20%, and PEEK/>30%. METHODS: For Martens hardness (HM) measurements, 40 specimens of each PEEK quality were fabricated and air-abraded with 50μm Al2O3. HM parameters of PEEK specimens were measured initially and stepwise after irradiating for 5, 10, 20, 30, 40, 60, 80, 100, 180, 360 and 540s using light units with different wavelength: Elipar S10 (430-480nm), EyeVolutionMAX (385-390nm+465-470nm), Translux CL (380-500nm) and bre.Lux Power Unit (370-500nm). HM parameters of 10 human teeth were measured initially on enamel and dentin. Data was analysed using 3-way ANOVA with partial eta-squared (ηP2) and post-hoc Tuckey-HSD-test (p<0.05). RESULTS: PEEK qualities followed by the wavelength showed the highest effect on Martens hardness (p<0.013). PEEK/>30% (197.35±19.9N/mm2), followed by PEEK/20% (191.45±15.49 N/mm2) showed significantly higher values for HM than PEEK/0% (189.55±16.89N/mm2). PEEK/>30% (5.49±0.4kN/mm) and PEEK/20% (5.38±0.26kN/mm2) presented higher indentation modulus (EIT) than PEEK/0% (4.77±0.36kN/mm2). Irradiated with wavelength of 430-480nm (PEEK/0%: 193.28N/mm2, PEEK20%: 198.83N/mm2, PEEK/>30%: 200.5N/mm2) indicated higher HM compared to specimens irradiated with 380-500nm (PEEK/0%: 186.63N/mm2, PEEK20%: 191.05N/mm2, PEEK/>30%: 196.13N/mm2). Irradiation using 430-480nm (PEEK/0%: 4.95kN/mm2, PEEK20%: 5.52kN/mm2, PEEK/>30%: 5.59kN/mm2) and 370-500nm (PEEK/0%: 4.92kN/mm2, PEEK20%: 5.43kN/mm2, PEEK/>30%: 5.53kN/mm2) indicated higher EIT values compared to specimens irradiated with 380-500nm (PEEK/0%: 4.72kN/mm2, PEEK20%: 5.34kN/mm2, PEEK/>30%: 5.47kN/mm2). Duration of irradiation presented no impact on results. Enamel (HM: 2263.6±405.16, EIT: 63.16±19.24) and dentin (HM: 468.2±30.77N/mm2, EIT: 14.14±4.59kN/mm2) presented significantly higher HM and EIT than the tested PEEK qualities (p<0.001). SIGNIFICANCE: Irradiation with different wavelength impacted HM parameter. The increase of TiO2 percentage in PEEK matrix improved the HM parameter. However, PEEK showed significantly lower HM parameter than human teeth.