Influence of Apical Plug Material and Thickness on the Fracture Resistance of Simulated Young Immature Permanent Incisors: An in vitro Study

Abstract

Background: Traumatic dental injuries, deep caries, and pulpal pathosis affecting young permanent teeth often interrupt normal root development, resulting in immature teeth. Apexification is a well-established treatment modality for managing non-vital immature teeth, aimed at creating an apical barrier that allows effective obturation of the root canal system. The thickness of the apical plug plays a crucial role in achieving an effective apical seal and influencing fracture resistance.

Aim: To evaluate and compare the fracture resistance of various root end filling materials of different thicknesses in simulated young permanent incisors.

Materials and methods: A total of 56 human permanent maxillary incisors were selected and equally distributed into three experimental groups (each with two subgroups) and two control groups (Groups I and II). The experimental groups were subdivided based on apical plug thickness (3 mm and 6 mm). Access cavities were prepared in all groups except the negative control (Group I). A 3 mm apical plug was placed in Groups IIIA, IVA, and VA. In comparison, a 6 mm apical plug was placed in Groups IIIB, IVB, and VB using MTA, Biodentine, and Dyract compomer, respectively. The positive control group was obturated with calcium hydroxide (Group II) to the whole length other three groups were obturated with GP with AH Plus sealer. All the samples were then subjected to fracture testing under a Universal Testing Machine, and fracture strength was recorded. Data were analysed using one-way analysis of variance with the Tukey post hoc test for multiple comparisons.

Results: The negative control group exhibited the lowest fracture resistance compared to the other groups (P < 0.0001). The Biodentine group with a 6mm thickness of apical plug showed the highest fracture resistance.

Conclusion: MTA, Biodentine and Dyract compomer can be used as an apical plug to increase the fracture resistance of immature teeth.