Should Article 17(1) and (2) of the Sixth Directive be interpreted to mean that if a national statutory provision, contrary to the Directive, provides for an exemption (in respect of which the right to deduct is excluded), the taxable person is entitled to the right to deduct in reliance on Article 17(1) and (2) of the Sixth Directive? Should Article 143(a) and Article 140(a) and (b) of the 2006 VAT Directive be interpreted to mean that the VAT exemptions contained in those provisions do not apply to the importation and the intra-Community acquisition of dental prostheses? If the answer to that question is in the negative, is the application of the exemptions then subject to the condition that the dental prostheses must have been supplied from another country by a dentist or dental technician and/or supplied to a dentist or dental technician?