IADR Abstract Archives
Benefits of Spectrometer Method Inclusion into ISO 10650 (2018)
Objectives: This study examined the importance of recent changes to ISO10650 “Powered polymerization activators” also known as dental light curing units (LCUs).
Methods: Over eighty-five thousand LCUs from over 30 countries representing 576 different models of LCUs were measured using the spectrometer method in ISO10650(2018). checkMARC (BlueLight Analytics, Canada) incorporates an STS spectrometer (Ocean Optics, USA) with wavelength range covering the required range of 350nm to 700nm. Factors affecting LCU output were indicated; damaged tips, contaminated tips and use of infection control barriers. Three measurements were taken from each LCU.
Results: Four groups of LCUs were identified by spectral characteristics; quartz-tungsten-halogen (QTH) 5.3%, plasma-arc (PAC) 1.4%, single-peak LED (LED-A) 76.3 % and multi-peak/broad spectrum LED (LED-B) 17.0%. 24.4% of total LCUs did not provide manufacturer stated output for the mode tested or the model was too outdated to find documentation. 46.6% of total LCUs had a clear manufacturer stated output and measured within ± 20 % as required in the standard. 27.4% of LCUs that were free of damage, contamination and barrier measured outside of ± 20 % of the manufacturer stated. The spectral data identified damaged filters in QTH/PAC LCUs which increased irradiance values required to be limited outside of 380nm to 515nm. Several LED-B LCUs that experienced a reduction in output (>20%) showed a non-uniform degradation as violet and/or blue LEDs would burnout at different rates. (see fig.1)
Conclusions: Some models of LCUs had outputs far exciding the manufacturer stated and could be indicating a different method to the ISO10650 was used.
The spectrometer method was able to detect changes in spectral distribution in the ranges outside of 380nm to 515nm for QTH/PAC LCUs.
The spectrometer method was able to detect changes related to the non-uniform degradation of violet and/or blue LEDs in LED-B LCUs.
Methods: Over eighty-five thousand LCUs from over 30 countries representing 576 different models of LCUs were measured using the spectrometer method in ISO10650(2018). checkMARC (BlueLight Analytics, Canada) incorporates an STS spectrometer (Ocean Optics, USA) with wavelength range covering the required range of 350nm to 700nm. Factors affecting LCU output were indicated; damaged tips, contaminated tips and use of infection control barriers. Three measurements were taken from each LCU.
Results: Four groups of LCUs were identified by spectral characteristics; quartz-tungsten-halogen (QTH) 5.3%, plasma-arc (PAC) 1.4%, single-peak LED (LED-A) 76.3 % and multi-peak/broad spectrum LED (LED-B) 17.0%. 24.4% of total LCUs did not provide manufacturer stated output for the mode tested or the model was too outdated to find documentation. 46.6% of total LCUs had a clear manufacturer stated output and measured within ± 20 % as required in the standard. 27.4% of LCUs that were free of damage, contamination and barrier measured outside of ± 20 % of the manufacturer stated. The spectral data identified damaged filters in QTH/PAC LCUs which increased irradiance values required to be limited outside of 380nm to 515nm. Several LED-B LCUs that experienced a reduction in output (>20%) showed a non-uniform degradation as violet and/or blue LEDs would burnout at different rates. (see fig.1)
Conclusions: Some models of LCUs had outputs far exciding the manufacturer stated and could be indicating a different method to the ISO10650 was used.
The spectrometer method was able to detect changes in spectral distribution in the ranges outside of 380nm to 515nm for QTH/PAC LCUs.
The spectrometer method was able to detect changes related to the non-uniform degradation of violet and/or blue LEDs in LED-B LCUs.
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