BugBrush will last approx. 9-12 months, it depends on how often the child uses it and for how long. You can ensure the bristles remain straight by putting it in a bowl of boiling water each evening. This also sterilises it. You can use cold water or steam sterilisation, or a dishwasher. Please note that high temperature sterilisation will reduce the life span of the product as it will weaken the plastic. You need to replace at the first sign of wear, and when more than 40% of the bristles are flattened.