Hii

Last year NEET scores have become invalid now. NEET scores are alid only for 1 single year and NEET 2018 scores could be used to get admission only for the session 2018-19. The admissions for that session have ended.
This time admission processes are going on for the session 2019-20. To get admission into dental colleges this year,you will have to appear  in NEET 2019.
The cutoffs vary every year so it is not possible to predict what score will allow you to get admission this year but as per last year trend in general category around 450-500 marks are required for admissions to top bds colleges. 

Hope this helps
Thanks!