The UMKC School of Dentistry suggests candidates observe for a minimum of 100 hours in at least five different dental offices, and they give preference to candidates who have worked in a dental office.
You can begin by arranging an informational interview and a day or two of shadowing experience with your own dentist, and you can search for other dentists to ask in the area. When you really click with a dentist, shadowing sometimes sets the occasion for an, "Oh, by the way, I'm looking to hire someone to help with reception or billing this summer," conversation, which in turn sets up the possibility of getting trained to assist.
The University Career Center can help you put together a resume. Then, search for all the local offices. Introduce yourself, and leave a resume that they can keep on file. Check back every semester or so, to update your resume, and let them know you're still interested in a position. Also, let your friends and family know you're looking for a job as a dental assistant.
The Pre-Dentistry Club has been a very helpful network for learning about job opportunities.
There are many other ways to gain experience. The UMKC School of Dentistry has extended a standing invitation to shadow dental students in their clinic. To make a reservation, call 1-800-776-8652.
In addition to dentistry experiences, dental schools, including UMKC, emphasize a demonstrated commitment to social service. You can find opportunities through Volunteer Douglas County and the KU Center for Community Outreach.
Especially if you have some experience working in a dental practice, you might be interested in volunteering at the Douglas County Dental Clinic. They need volunteer dental assistants and experienced office staff to help provide services at the clinic.
KU students also regularly volunteer to help with the Kansas and Missouri Missions of Mercy, annual events in which many dental professional and volunteers gather to serve many people, who cannot afford dental care.
Part of dentistry is applied science, and it's helpful to know how this knowledge is developed. Working on a research project is also a good way to earn a substantial recommendation letter from a faculty member who knows you well. Most students volunteer their help, some earn directed study credit, and a very few are paid for their assistance. To get involved, you can start at the Center for Undergraduate Research.
When you apply, it will be important to fully describe your activities. So, I suggest keeping a log of your hours, activities and thoughts about the profession!