This question, for the record, is referring to what happens when the current blades of your system begin to wear down. Thankfully, though, serrated blades, in general, are razor sharp and are probably going to last the extent of the unit. But, if you do notice that the blade’s performance is a shell of what it used to be, you can do one of two things. Some people believe that sharpening electric knife blades is impossible and while it may be easier to simply just buy replacement blades, it can be done.
The answer to this question is truly up to you. If you do not feel like going through the hassle of sharpening your old blades, buy replacement models.