Dental implant and diabetes

I just found out that I have a fractured tooth and need to get a dental implant. There is infection in there and needs to be done. I do no thave dental insurance- not that it would even come clsoe to covering the cost...around $7,000! I am single mom - no child support to help me- and a teacher. You would think that I wouldn't have such bad luck! Am I am going to attempt to get Harvard Pilgrim- my medical insurance to cover part of it. They will cover impacted wisdom teeth and I know it is a S_T_R_E_T_C_H but I was hoping that my diabetes may help make a case for it being "medically necessary". Does anyone have any thoughts on this?