Hi all, I wanted to share my experience. I had two teeth drilled, one on Monday and one today. I also did some experiments with ear protection and the occlusion effect.
Monday
I used all the protection I had: foam earplugs rated at 30 dB and Peltor X5A earmuffs rated at 37 dB. The sound of the drilling was loud but manageable. I could not really hear the suction. I did not take any sound measurements.
Today
I did not use any protection, and the sound of the drilling was actually much quieter. This time I could hear the suction, but overall the sound of everything seemed quieter and easier to manage. I kept my phone a few centimeters from my mouth during the whole procedure, and the average noise was 71 dB, with the highest reaching 86 dB.
On both days, the dentist drilled for as long as needed. I did not ask for breaks every few seconds. In total, the drilling only lasted a few minutes each day. The dentist paused occasionally, but only when he needed to.
Summary
On both days, I did not experience any spike in my tinnitus from the drilling. The lesson I learned is that, for me, the experience was more manageable without hearing protection.