Complex sentence: The dental surgeon who carried out the procedure commented that MacGowan had recorded most of his great works while he still had some teeth; the new teeth had "effectively retuned his instrument and that will be an ongoing process".
Split into simpler sentences: The dental surgeon who carried out the procedure commented that MacGowan had recorded most of his great works while he still had some teeth. The new teeth had "effectively retuned his instrument and that will be an ongoing process".