2002-My left first molar was extracted. 2003-dentist placed cantilever bridge using the two front teeth. 2013-bridge detached while brushing but was fitted back. Recently,porcelain from middle unit broke.After a week,I am sensing slight sensitivity.Dentist said my teeth under bridge may be decayed.He was unsure even after xray & said he needs to break bridge to see teeth underneath.I get scaling done in 6months.None told me of decay which they might have observed.Could you please scan my xray.