Is ptfe and bioplast as a tongue ring better that the metal?

There are benefits to using them once the piercing has healed, however a properly sized piercing done with a steel shaft will allow the piercing to heal faster. Keeping the piercing straight during the healing period will allow the piercing to discharge and season up faster, plastics and Teflon tend to allow the tongue to bend them, this can be problematic during the healing period.

Folks also tend to goof around with the piercing where if metal were in place they wouldn't be able to bend the jewellery and further irritate the piercing. Another point to keep in mind is the step down barbell needs to be used after the first two weeks, this should also be metal to allow for the discharging to occur during the last 4 weeks of the initial healing period. Plastics have there place but should only be used after the piercing has gone through the first 6 weeks post piercing with metal shafts.

Plastic will be bitten, played with and bent, the last thing you want is to have a client goofing around with a new piercing and damaging the barbell or biting it off. They don't fool with metal that way because it's impossible to due to the swelling. Once the swelling is eased they will goof around but they know they have metal in the piercing and damage to the teeth is a real ever present danger.