Which technology is best in 3D printing&what materials used?

It depends on the application really. types of 3d printing technology

Stereolithography(SLA) process generally looks better with smoother surfaces and a higher level of detail. But, this does depend on the part. SLA could also be more accurate.

For manufacturing end use parts generally SLS is currently the better technology. This is because the parts suffer less from UV degradation and are generally stronger. Throughput on SLS machines is higher than SLA. SLA generally has a higher cost level overall because supports must be removed by hand and often the part is filed down. 3d printing andhra pradesh orissa jharkhand bihar india
Having said that, millions of hearing aids are produced each year through 3D Printing and that is done using SLA and DLP machines.

If you need it too be smooth, pick SLA. For hearing aids and similar things when one is making many similar parts SLA would also be a good choice because you can (partially) eliminate support removal. If you need it to be tough then SLS will be a better choice. If the porosity of SLS is an issue then SLA would be better. If you make lots of different geometries of parts then SLS would be easier and work more often. Part geometry and the end use of the part also plays a big role in which technology would be better.

HD Mechanical - spot S-Pro- SLA resin

investment castable resin(IC) - 3D Printing Materials for Jewelry

flexible sla resin - HD Elastic

durable tough resin - HD strong

Snow White Resin - HD white