Introduction
In dental and medical radiography, developer and fixer solutions are essential chemicals used to process X-ray films. These chemicals help convert the invisible latent image into a permanent, visible diagnostic image.
X-ray Film Developer
The developer solution is the first step in film processing. It converts the exposed silver halide crystals on the film into black metallic silver, making the latent image visible.
Composition of Developer
- Developing Agents (Metol, Hydroquinone): Reduce exposed silver halide crystals.
- Accelerator (Sodium Carbonate): Maintains alkalinity and activates developer.
- Preservative (Sodium Sulfite): Prevents oxidation of the solution.
- Restrainer (Potassium Bromide): Prevents fogging by controlling development.
Role of Developer
- Produces the visible image.
- Enhances contrast and sharpness.
- Prepares the film for the next step (fixing).
X-ray Film Fixer
After development, the fixer solution makes the image permanent and light-resistant by removing unexposed silver halide crystals.
Composition of Fixer
- Fixing Agent (Sodium Thiosulfate or Ammonium Thiosulfate): Clears unexposed crystals.
- Acidifier (Acetic Acid): Neutralizes developer and provides an acidic medium.
- Preservative (Sodium Sulfite): Prevents decomposition of thiosulfate.
- Hardener (Potassium Alum): Hardens the film emulsion for durability.
Role of Fixer
- Removes unexposed silver halide crystals.
- Makes the image stable and permanent.
- Provides long-term clarity and durability.
Processing Cycle with Developer & Fixer
1. Developer – Converts latent image to visible image.
2. Rinse – Stops the action of the developer.
3. Fixer – Removes unexposed crystals, hardens film.
4. Wash – Removes chemical residues.
5. Dry – Prepares the film for storage and diagnosis.
Safety & Handling Tips
- Always use gloves when handling chemicals.
- Store in airtight containers away from direct sunlight.
- Replace solutions regularly for best results.
- Dispose of used chemicals according to safety regulations.
