Need some advice here

First off I'm new to this site so I don't know if this subject has been posted or not, but I need some help here and I don't know where I should go next with this issue I'm having at work. I am a 1st shift stna at a long term nursing and rehiblitation facility. I have been there for 4 months. My nursing career started 2 1/2 years ago at the facility I first started to become an stna, so I have only worked for now, 2 companies. I have hopes and dreams of staying where I am at now and want to further my field this fall with becoming an LPN and staying with them. So, here's my problem...our company has recently hired on new girls on 2nd shift as young as 17 and 18 years old, now while they are nice girls, it just seems that they are there for their paychecks. I am so serious when it comes to my patient care and how our residents are treated. More often anymore when I come on first shift I am finding dentures left in our residents mouths, residents not being turned on turning schedules, dentures left in just their cups of water, not brushed and or effordent not added, and rehibilation braces being left on overnight. I'm hearing from laundry that while residents clothes are being sent to laundry on a nightly basis, that there are no towels or washrags to accompany them. My speculation is that the residents are not being properly washed before bedtime and that pm care is not being done. Now I have addressed this to my nurses and I have even made a stink about to my director of nursing. I feel like I'm talking to a brick wall!! Nothing is changing. I know that I am not totally perfect at my job, but you better believe when it comes to the care I always give 100%! A couple of my residents have even complained to us on 1st shift that they are very upset when we go home, because they know these young girls are coming on and all they want to do is the bare minimum and stand around and talk about what's going on in their lives. I have stayed over a few times and I know what our residents are talking about. I feel like I'm carrying a heavy chip on my shoulder and I carry this home with me every day wondering how my residents are being taken care of. It just seems after talking with my DON she says things will get better, but as long as our shifts are covered and spaces are filled that everything looks better. I say hogwash...while it looks better on the outside not all is well on the inside! I don't want to sound like I am constantly complaining being that I am new to this place, but I am really feeling bad about all of this! I'm not sure if I should just shut my mouth and walk away because it seems like I am fighting a losing battle, or if I should stand up and persue this further and who do I go to next? I don't want to get my director of nursing in any trouble, because it does seems like her hands tied as well, but I just don't know what to do. Any suggestions???? Thanks, Julie