MDS

You should pursue a course where your interests lie, and one you feel comfortable doing/studying. Both have comparable scope, and nothing much to choose between the two. I am populating scope for both fields, and you can compare the two and decide on your own. Good Luck!!
The aspirants who have completed their Master in Dental Surgery have a good scope both in terms of higher studies as well as in acquiring an immediate job. Higher education is one of the means by which one can acquire a greater knowledge and hence pursue a good career. Also the candidates after completion of MDS can apply for jobs.
The growth of healthcare management in India has been immense and the industry is growing at about 15% every year since 2010. The scope for careers in Hospital Administration is increasing significantly with a huge number of private hospitals set to be established in the country. The industry has realized the importance of specialized administrators and the sector is becoming one of the most popular in terms of employment. As an MBA in Hospital Administration you will learn the principles of management, efficient business handling as well as the nuances of what goes into the administration of healthcare facilities all around the world. You will have the opportunity to become a management professional of the highest ethical standards and help patients all around the world get timely and efficient access to treatment. It is one of the most promising courses and there is a lot of scope for growth and learning opportunities.

It will depend on what area in the corporate world would you be keen on based on your interest area:
If you are a peoples person & like engaging with people then you could pursue MBA in HR & join HR in a dental mfg /product distribution company.
If you are keen on sales/marketing then you could pursue MBA in marketing and join a pharma /FMCG/dental product mfg setup in their sales/marketing team.
If you are keen in finance then you could also pursue MBA in finance & join an Equity Broking house and start tracking Pharma/hospital companies & thus use your medical knowledge in understanding the business of the said companies better.
You could also do MBA in hospital management & manage the administration of hospitals.
As I said, all will depend on your interest areas & career aspirations.