Porcelain? OOPS!
The ceramic might pose a problem - plugs have a ceramic insulator - so if pieces of that "glass insulator" fell into the cylinder, then you might have a problem - it usually will "grind up" but the sediment glass will still be in the system and the oil.
So it can run, but it might mean a short interval for the next oil change and if possible a snake camera to view the cylinder piston and walls to compare it with another known clean cylinder to compare for damage if any.
That porcelain is silica - so it's basically a sand - or grit found in Sand-paper - so small amount? Even then requires a disassembly (pull out those plugs) and vacuum it out if you're not sure - so the particles still in the cylinder can be removed - but if the engine was already driven - then this point is moot.