Non-surgical rhinoplasty is great to raise a low bridge
Fillers can be a great, and much cheaper, way to reshape the nose. They are great for the type of issue you describe, which is raising a low bridge, especially when you have a low radix (where you nose takes off from your forehead). Adding filler here can actually make the nose look smaller and straighter. In terms of how long the filler will last, it depends on which filler is used. Some last 9 months or so and others can last up to 2 years. Personally I would not advise a permanent filler in the nose. Unless you have different plastic surgeons injecting different fillers at different times (some that last longer than others), it should not look weird as it wears off. The best thing to do is see a surgeon who is also skilled at rhinoplasty since the evaluation of the nose, and understanding the anatomy, is key.
Non Surgical Rhinoplasty Candidate
Please post photos for further evaluation. For a non-surgical intervention, fillers can be used to sculpt the nose. I tend to use a lot of Voluma for this area and achieve great results. I do not like permanent fillers here as long term there can be issues, but Voluma will last approximately two years and will slowly resolve. I suggest a physician who is an expert in facial contouring to do a formal assessment. Dr. Emer