| Background: Presence of voids at root canal wall‒apical seal material interface gives rise to the entrapment of
toxins and microorganisms, which might have a relationship with post treatment disease. The present study was
carried out to evaluate the effect of different mixing (manual and ultrasonic) and placement (manual and manual
in association with indirect ultrasonic) methods of Calcium-enriched Mixture (CEM) cement on the number and
dimensions of voids in the apical plug in simulated apexification models.
Material and Methods: A total of 80 human maxillary central incisors with mature apices were selected. After
simulation of the open apices, the teeth were divided into 4 groups (n=20) based on the mixing and placement techniques
of CEM cement: group 1, manual mixing‒manual placement; group 2, manual mixing‒manual placement
in association with indirect ultrasonic technique; group 3, ultrasonic mixing‒manual placement; and group 4, ultrasonic
mixing‒manual placement in association with indirect ultrasonic technique. The samples were placed within
gypsum sockets in which the periodontal ligament was reconstructed with polyether impression material. After
placement the apical plugs, a wet piece of cotton was placed on canal orifices, followed by dressing with Cavit.
The samples were incubated at 37°C and 100% relative humidity for 7 days. Then the voids between the material
and root canal walls were counted with the CBCT technique. The void dimensions were scored with the following
scoring system: score 1, no voids; score 2, the void size less than half of the size of the evaluated cross-section;
score 3, the void size larger than half of the size of the evaluated cross-section. Statistical analyses were carried out
with chi-squared and Fisher’s exact tests. Statistical significance was defined at P<0.05. |