Why dont people use more glass in dentistry?

I type in glass dental fillings, glass tooth implants etc. Search engines return nothing, i call around to local dentists nobody knows anything. I soon find out there are only 4 or so fillings that everyone uses. Does anyone in the US even use any glass in there practice. Would like to find someone here that would know about the placment of glasses. People say there not strong enough for bite force and dont last long. There are hard molar strenght glasses!, ive seen many strong glasses in my time. Any Non-ionomer-fluriodated glass?

Any suggestions?

Could someone recommend a good glass filling material and someone to place it? Im only aware of one biocompatability facility in the USA in colorado. Is there one in texas?

Any suggestions for glass implants? (a carved glass tooth replacment)