Is it because I’m 60 years old? That’s why my teeth won’t whiten?

As we get older the layer after the enamel (outer layer), which is dentin gets denser and more sclerotic which appears as yellow to brown color! Bleaching teeth will take longer, and the concentration may be altered to see results! Of course all that depends on the health of your gums and lack of restoration on the untouched teeth!For a more permanent solution, you may explore porcelain, veneers, lumineers to cover the outer layer!Best,Dr Anthony Mobasser

Age doesn't necessarily preclude whitening from working. Some peoples tooth enamel simply will not change color. These are usually teeth with grayer tones. Yellow teeth will often whiten quite well. That being said, I would try an in office method like zoom to see if you can get results. If this doesn't work, porcelain veneers may be the answer.

For @54 years, you have had your permanent "adult" teeth and you still have them!  Congratulations, they have worked night & day, 24h non stop for over a half of a century.  In that time, organic stains and possible thinning of the enamel from attrition and/or acids in diet could make the interior of the tooth more visible.  That interior is also more porous and stain grabbing.I have had great results utilizing "Deep Bleaching" techniques, basically using two whitening methodologies as one larger bleaching session.  If that doesn't whiten, I usually will credit the cost towards ceramic veneers or crowns if physical coverage of the teeth becomes the only patient acceptable way of reaching their cosmetic goal.White teeth are still attainable, good luck!