Are there any risks or side effects, especially for older adults?

The short version: for an 81-year-old, the evidence for red-light mouthpieces is thin, and the risk is mostly wasted money, not physical harm.

The retrieved studies do not test a home-use mouthpiece device in older adults. The closest dental trial, from 2018, tested a 970 nm laser on 36 patients with an average age of 39, not 81 [1]. That study found no improvement in wound healing from the laser, though it did reduce discomfort [1]. A 2024 review of photobiomodulation across many fields notes that doses vary wildly and no standard exists [2]. A consumer mouthpiece may deliver a completely different dose than what was studied.

For an older adult, the real risks are not from the red light itself. Red light at the low power used in these devices is not known to burn tissue or cause cancer. The 2018 trial reported no adverse events [1]. But the risk is that you spend money on a device that does not work, delay real dental care, or rely on it instead of proven methods like professional cleaning and good brushing.

The mechanism is real in principle. Red light can stimulate mitochondria and reduce inflammation [2]. But that does not mean a specific mouthpiece delivers the right dose to your gums. No study here tested a device you can buy online. No study followed an 81-year-old user. The evidence does not support buying this product for gingivitis prevention.

My call: the device is unlikely to harm you, but the evidence that it helps is too weak to justify the cost, especially at age 81. Confidence: low.