Final answer:
The best index to evaluate the oral hygiene status of this group is the Simplified Oral Hygiene Index (OHI-S).
Step-by-step explanation:
The best index to evaluate the oral hygiene status of this group of teachers would be the Simplified Oral Hygiene Index (OHI-S). The OHI-S assesses the amount of plaque and debris present on the teeth using a simplified scoring system. It evaluates the presence of plaque and debris on six index teeth and provides a score ranging from 0 to 3.