RESUMEN
Aim: To evaluate the internal adaptation of some dental adhesive restorative material (Nano-composite resin /Biodentine,Nanocomposite resin / Nano- resin-modified glass ionomer and Nano-composite resin) to the primary dentinal surface usingmicro-computed tomography (Micro-CT) Materials and methods: Forty-five extracted primary molars, due to caries ororthodontic reasons, were collected provided that it has an intact buccal/ lingual surface(s) and one half to two-thirds ofroot length. The selected teeth were disinfected and stored in normal saline at room temperature. The teeth were randomlyassigned to one of the three experimental restorative groups according to the restoration type (15 per group): group A:Nanocomposite resin / Biodentine, group B: Nanocomposite resin / Nano-resin-modified glass ionomer and group C:restored totally with Nanocomposite resin. A high- resolution desktop micro-CT (Model 1172, Skyscan, Belgium) was usedto image the samples. Results: The mean rank of volumetric dimension values of the total gap at the restorative material –dentine interface demonstrated significant difference among the three groups (P= 0.003). Moreover, there was a significantdifference in the mean rank of the ratio of total gap volume/cavity volume among the three restorative groups (P=0.015).The data demonstrate that group A showed the lowest in total gap volume and mean ratio of total gap volume /cavity volumewhile group C recorded the highest value. Conclusion: Biodentine exhibited a higher internal adaptation to a dentinalsurface which is comparable to Nano resin-modified glass ionomer. The study results potentiate the importance of usingBiodentine liners under Nano-composite (sandwich technique) in terms of excellent internal adaptation, in addition to itshigh biocompatibility and easy handling as well.