1、 Equipment operation specifications

1. Calibration and Testing
   • Equipment calibration is required before use to ensure the accuracy of the light source and sensor. For example, a certain model of colorimeter requires placing the calibration cap on the probe, pressing the "MEAS" button, and waiting for 3 flashes of the light source to complete the calibration.
   • Regularly check the stability of the equipment to avoid strong magnetic field interference (such as near speakers), otherwise it may cause reading errors.
2. Sample loading and fixation
   • Samples (such as dental grinding blocks) should be firmly fixed in the carrier to prevent detachment or displacement during the staining process. For example, bovine enamel blocks need to be embedded with self setting resin to ensure that the liquid level is level with the thickness of the mold, and then dyed after the resin solidifies.
   • Avoid sample collision or oscillation to prevent equipment failure.
3. Optimization of operation process
   • The staining solution needs to be prepared in proportion (such as gastric mucin 2.5g/L, coffee 4.0g/L, etc.) and stored at 2 ℃ to 8 ℃, with a shelf life of only 3 days.
   • During the dyeing process, it is necessary to adjust the speed (such as 2r/min) and temperature (simulating an oral environment at 37 ℃) to ensure that the dyeing solution alternates with air circulation.

2、 Sample processing requirements

1. Sample selection and preparation
   • Select non caries and defect free bovine maxillary permanent incisors and cut them into standard sizes (such as 5mm × 5mm × 2mm enamel blocks).
   • The sample needs to undergo slight acid etching (such as 1% hydrochloric acid solution for 60 seconds) to accelerate staining. After acid etching, rinse immediately and place it in the staining apparatus.
2. Cleaning before dyeing
   • The surface of the sample needs to be cleaned to remove soft tissue residues and stored in a neutral solution.
   • Before staining, it is necessary to store the sample in deionized water to avoid contamination.
3. Post dyeing treatment
   • The stained samples should be used immediately for the experiment, and unused samples should be stored in deionized water for future use.
   • Avoid sample dehydration or excessive exposure to air to prevent changes in staining effect.

3、 Environmental and Safety Control

1. environmental conditions
   • The dyeing process needs to be carried out at a constant temperature of 37 ℃, simulating the oral environment.
   • The operating area should be kept clean to avoid contamination, oil stains, or smoking, and to prevent sample contamination.
2. safety protection
   • Dyeing solution may contain acidic components (such as hydrochloric acid), gloves and goggles should be worn during operation.
   • The staining instrument sink needs to be cleaned regularly to prevent bacterial growth.
3. waste disposal
   • Dyeing solution and waste liquid should be treated according to laboratory standards to avoid direct discharge.
   • Abandoned samples need to be disinfected and discarded.

4、 Special scenario precautions

1. Staining of long bridge or half mouth restorations
   • It is necessary to extend the heating and cooling time to prevent insufficient sintering from causing color "death".
   • The planting opening position should avoid staining solution to prevent the color of the neck from becoming lighter.
2. Dyeing of zirconia restorations
   • The brushing sequence must be strictly followed (such as cutting the end first and then E0 missing position), and the thickness should be controlled using a No.6 ceramic pen.
   • The soaking time needs to be adjusted according to the thickness of the restoration (for example, if the 1.5mm sample is soaked for 120 seconds, the color may become darker).
3. Color deviation correction
   • If the color scheme is biased towards red, yellow, or gray, it is necessary to adjust the dye formula or sintering temperature (such as 1530 ℃ as the ideal temperature).
   • When there is a deviation in transparency, the number of times the transparent treatment solution is applied can be increased.