Resistance to fracture evaluation of endodontically treated roots of first maxillary premolars

Resumo

One of the most common dental procedures associated
to vertical root fractures is the endodontic treatment with excessive
dentin wall wear and another increasing risk factor is the use of
intraradicular post. Objective: This study evaluated the resistance to
fracture of the buccal and palatal roots of maxillary first premolars
with endodontically treated canals and spaces for posts. Material
and methods: Twenty two first permanent premolar roots (11 buccal
and 11 palatal) composed the experimental sample. The canals were
prepared with Protaper Universal® system until file F3 and then
filled with gutta-percha cone F3 and endodontic sealer and received
spaces for posts keeping 4 mm of filling at the apical third. The roots
were subjected to compression test in a universal testing machine
(Kratus). The roots were subjected to a progressive compression
stress at a speed of 0.5 mm / min. A load cell of 200 kg was used.
Results: Statistical analysis revealed significant differences between
the strength values and resistance limit between groups (P<0.05),
as analyzed by t Student test. The values of resistance to fracture
of 0.44 kgf/mm2 for group 1 (buccal roots) and 0.31 kgf/mm2 for
group 2 (palatal roots) were found. Conclusion: The resistance to
fracture of the buccal roots was higher than that of palatal roots
of first premolars submitted to biomechanical preparation and root
preparation for intraradicular post.