NOTHING deserves 100% trust.
can we trust science 100 % or what?
Science isn't really an "entity" that you put "faith" in, despite some people's attitudes toward it. Science is really just a method of discovering truth. You can trust the method if it's applied properly, but the conclusions are always subject to change and refinement.
As long as it's done correctly
Much of science is based on theory and hypothesis. As we learn more those theories and hypotheses change. If you look at what was once considered medicine through chemistry, you might be surprised. Look at this old bottle of cough medicine. Some of the ingredients alone is one issue but combined is a whole other thing. It makes me wonder how many people who counted as dying from a disease actually died from what was passed of as medicine.
Science is less a thing than a method; to accumulate and refine understanding. It is not infallible, but, applied intelligently, is far more reliable than the alternative.