financial dentist

refers to someone who provides a low-income person with the most ideal and reasonable/healthy type of monetary -ssistance — he simply “fills in the gaps” in the indigent person’s financial life, such as purchasing economy-grade groceries, buying a few separate tools (extra points if the person requests/accepts used tools from a thrift store or yard sale) to replace broken/worn/missing ones in the person’s toolbox, providing maintenance/repair materials to fix/upgrade things around the person’s house, and so on.
financially-solvent dude: i really appreciate how tiffany only asks me to be a financial dentist for her, rather than expecting me to buy her everything under the sun. plus not only does she never try to pressure me to go along on any of her boring mall-shopping trips, but she also always cuddles up with me while i’m browsing amazon/e-bay to locate the lowest price on the occasional replacement item or tape/disc that she wants, and accompanies me hand-in-hand to goodwill or the local p-wn-shops/thrift-stores whenever i go scrounging for bargains on the few simple household/recreational items that she does ask me for… her warm-hearted grat-tude-filled companionship during these somewhat-tedious endeavors is an welcome bonus all on its own, of course, but her always being at my side also means that she’s right there to actually observe and inspect each of the items that i’m thinking of choosing for her, and so she can more easily/reliably determine if the item i’m looking at is indeed the best choice to fulfill her needs.