The solid state circuitry in these cameras are likely to outlive the usefulness of the device. That said, the only parts of the camera that could conceivably break from normal use (and even this is very unlikely) are the the pan-tilt motor and the moving part responsible for switching between day and night mode (I've read of one instance in this forum where the night mode shutter broke)
That said, if you want to be ultra-conservative, I presume you can simply not use the pan-tilt motor and leave the camera in daytime mode.