Dental Supragingival plaque undergoes which of the following changes with time? A Plaque mass decreases B Plaque microflora becomes more gram positive C Plaque microflora becomes gram negative D Plaque microflora becomes predominantly spirochetal 💡 Explanation Supragingival plaque undergoes which of the following changes with time? ✓ Correct Answer: C. Plaque microflora becomes gram negative