The number of times you need to open and close a dishwasher for dishes to get clean depends on the specific dishwasher model, the cleanliness of the dishes before loading, the amount and type of detergent used, water hardness, and the dishwasher's wash cycle settings.
In a typical dishwasher cycle, which usually includes pre-wash, main wash, and rinse cycles, the dishwasher will automatically open and close several times throughout the process. However, from a user's perspective, you generally only need to open and close the dishwasher once per cycle—when you load the dirty dishes and then again when the cycle is complete to unload the clean dishes.
If the dishes are heavily soiled or if you're using a shorter or lighter wash cycle, you may need to run the dishwasher multiple times to ensure the dishes are thoroughly cleaned. It's important to follow the manufacturer's guidelines and use the appropriate detergent and settings for optimal cleaning performance.
Overall, the exact number of cycles required to get dishes clean can vary, but one complete dishwasher cycle is usually sufficient in most cases.