The Use of Micro-Computed Tomography for Evaluation of Internal Adaptation of Dental Restorative Materials in Primary Molars: An In-Vitro Study

Abstract

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 using micro-computed tomography (Micro-CT) Materials and methods: Forty-five extracted primary molars, due to caries or orthodontic reasons, were collected provided that it has an intact buccal/ lingual surface(s) and one half to two-thirds of root length. The selected teeth were disinfected and stored in normal saline at room temperature. The teeth were randomly assigned 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 used to 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 significant difference 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 volume while group C recorded the highest value. Conclusion: Biodentine exhibited a higher internal adaptation to a dentinal surface which is comparable to Nano resin-modified glass ionomer. The study results potentiate the importance of using Biodentine liners under Nano-composite (sandwich technique) in terms of excellent internal adaptation, in addition to its high biocompatibility and easy handling as well.