Save TFT screen over long period of time?

For a TFT screen such as the 3.5 or 4.3 inch available in gadgeteer version, what are reliability concerns over long period of time (1 year, 3 years, 5 years+ ) ?
-Does changing the content on the screen really helps ? (like old screen savers)
-Would adjusting the brightness on the screen help (for example control the PWM led driver with an analog out?
-what other concerns I should worry about on about longetivity of TFT screens?
-Any possible way to detect a failed screen remotly (without anyone seeing that the screen is not working)? I though about putting a current sensor, and if the PWM led driver circuit is dead, maybe the total current consumed would drop and I could raise an alarm remotly…

Right now Ihave a TE35 gadgeteer screen mostly opened with the same image for over 6 months, with no apparent problem or deterioration.
But I would like to plan ahead for our product.

In the case of LCDs, the mechanics of burn-in are different than plasma and OLED, which develop burn-in from luminance degradation of the light-emitting pixels. For LCDs, burn-in develops in some cases because pixels permanently lose their ability to return to their relaxed state after a continued static usage profile. In more typical usage profiles this image persistence in LCD is only transient.

Both plasma-type and LCD-type displays exhibit a similar phenomenon called transient image persistence, which is sometimes confused with screen burn but is not permanent. In the case of plasma-type displays transient image persistence is caused by charge build-up in the pixel cells (not cumulative luminance degradation as with burn-in), which can be seen sometimes when a bright image that was set against a dark background is replaced by a dark background only; this image retention is usually released once a typical-brightness image is displayed and does not inhibit the display’s typical viewing image quality.