Carga máxima de carregamento e modo de falha de diferentes materiais e técnicas restauradoras oclusais em molares endodonticamente tratados

Abstract

Objectives: To test the fracture strength of endodontically treated molars restored with nanoceramic table tops or occlusal resin composites direct restorations associated or not to horizontal fiberglass post; and to evaluate the failure pattern after the fracture strength testing. Materials and methods: Eighty sound extracted third molar teeth received occlusal access, endodontic therapy and were randomly assigned into 8 groups (n = 10), according to intervention: occlusal access (AO); transfixed post (PT); transfixed post filled with composite resin (PTR); transfixed post filled with bulk fill (BFP); composite resin (RC); bulk fill resin (BF); occlusal laminates in LAVA nanoceramic resin (TTL); healthy teeth (H). The specimens were submitted to 500,000 cyclic fatigue loading at 200 N and subsequently, a fracture loading test was performed with compressive force along the tooth axis at cross-head speed of 1 mm/min. Results: The mean values obtained were, in N (means followed by the same letter do not present statistical difference for ANOVA and Tukey) (p > 0.05): H 4101 ± 476 A; BFP 2443 ± 317 B; TTL 2288 ± 461 B; PTR 2188 ± 262 B; BF 1672 ± 252 C; RC 1352 ± 257 CD; En 1193 ± 346 CD; AO 941 ± 342 D. The failure pattern was predominantly repairable for all groups, except to TTL with 70% irreparable prognosis. Conclusion: Endodontically treated molar teeth with traditional occlusal access presented a predominantly repairable prognosis, except to TTL group. The use of table tops or horizontally transfixed fiberglass post associated to Bulk Fill or conventional composite resins increases the fracture resistance compared to groups without fiberglass post.