To answer your question, the most important contribution of science and technology to health has been the ability to find cures for most ailments. There have been many contributions – the concept of wellness, diet, etc. The most important has been the ability to provide cures or preventive measures for the different ailments that afflict us. Progress in science and technology has meant the discovery of complex techniques to cure previously incurable diseases. The development of vaccines has meant that diseases like small pox have been totally eradicated. Advancements in technology have given surgeons the tools to come up with complex surgical equipment to make previously complicated surgeries simple and previously impossible surgeries possible.
Therefore, the single greatest contribution of science and technology to the field of health has been the ability to find cures. If there was no development in science and advancements in technology, most of the procedures and medication available today would have remained the subject of medical fantasy, not reality.
The most important contribution of science and technology to society is probably the advent of the biotechnology industry following the sequencing of the human genome. Not only did this event open up the key to understanding the nature of genes, noncoding DNA and other biological processes that were previously unexplored, it also helped to develop the infrastructure and technology to help explore the data produced. The biotechnology industry now is involved in many different aspects of society, but in terms of health, the most prevalent applications are the use of genetic screening for disease diagnosis, the applications of gene therapy, the comparison studies of polymorphism between individual humans and chimpanzee to discover differences that shape our uniqueness, the discovery of environmental factors that can modify our genetic makeup, and now the latest research on elements apart from genes that control the biological processes of organisms (non-coding DNA). Any one of these contributions can be regarded as being significant to health, depending on your angle. However, up to now, the sequencing of the human genome would be the event that started the genomic revolution, and that would be in my opinion the most important contribution, and the first significant co-operation between science and technology.