**1. Introduction**

This chapter describes a unique way to obtain a flexible pure hydroxyapatite film. In the past years, the nanocomposites have been in the center of attention due to their unique physical and chemical properties.

Specifically, the biomaterials have been widely studied, motivated by their clinical applica‐ tions. Among these, the hydroxyapatite has been studied due to its remarkable properties, such as biocompatibility, osteoconductivity, and bioactivity. This material is naturally found in the human body, being one of the major constituents of bones and teeth. As a consequence, HA has been widely used in many fields, including biomedical applications. Our experiments led to the creation of a thin HA film that has the role of protecting teeth against cariogenic bacteria and could even have cosmetic effects by teeth whitening. This dental plaster acts as an artificial HA enamel, very resistant and flexible, protecting the tooth and eliminating dental sensitivity. Being very thin, it is invisible once applied on teeth and can be observed only by examination under a strong light. The plaster, produced by pulsed laser deposition (PLD), can be manipulated with tweezers and applied on the tooth. The originality of our approach consists in the fact that the flexible HA film can be obtained in pure state, because it grows without a substrate, using just a base and lateral supports between which it will grow on vertical direction.
