my hygiene puzzle

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Across
  1. 3. a rope on tooth surface
  2. 5. chemical compound with low toxicity
  3. 6. help build bone and tooth enamel
  4. 8. opposite of red blood cells
Down
  1. 1. solid phase
  2. 2. house for bacteria, parasites, or other disease-causing agents
  3. 4. hard deposits on teeth
  4. 6. microorganism that needs molecular oxygen
  5. 7. dead bacteria