Any new implant or individual tooth replacement idea for back molar w/major bone loss w/out lengthy bone grafting? (Photo)

30 yr old 3 tooth bridge —#28 to 30 removed for decay under #30. Little structure left; the root is dying. Implant #30 ok; cap #28 ok. #28 under needs yr of grafting. I need to go on Fosamax ASAP. Was told the new bridge on #29 w/root canal will be unstable, hard to keep clean--alarming for jaw necrosis. Any creative ideas for filing #28 space soon--1-tooth denture, mini-implant w denture, kill #29 for the implant to implant bridge, some new technique? No dentist wants to touch this-suggests another technique.