Possible Clues:

• Seems that Doctor Laurence is the one for backbiting
• Grinding backbiter
• Tooth damage includes hole where surface is gone
• Tooth doctor a household god?
• It may be drilled before it's filled
• Grinder of a sort
• Grinder of an amount of chemical matter
• Large 16-Across
• One of a human dozen
• It might be impacted