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Evaluation of bond strength, nanoleakage and marginal adaptation of bulk-fill resin composites submitted to thermomechanical aging

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Author(s):
Renata Pereira
Total Authors: 1
Document type: Master's Dissertation
Press: Piracicaba, SP.
Institution: Universidade Estadual de Campinas (UNICAMP). Faculdade de Odontologia de Piracicaba
Defense date:
Examining board members:
Flavio Henrique Baggio Aguiar; Núbia Inocencya Pavesi Pini; Giselle Maria Marchi
Advisor: Flavio Henrique Baggio Aguiar
Abstract

This study aimed to evaluate the microtensile bond strength (BS), nanoleakage (NL) and marginal adaptation (MA) of three light-cured bulk-fill composites, comparing them with a conventional nanocomposite, after being submitted or not to mechanical and thermal cycling (MTC). Ninety-six healthy human third molars were selected and divided into 8 groups (n=12), according to the composite type: Filtek Z350 XT ¿ 3M ESPE (Z350), Tetric N-Ceram Bulk Fill ¿ Ivoclar Vivadent (TET), Filtek Bulk Fill Posterior Restorative - 3M ESPE (FBF) and SonicFill ¿ KAVO Kerr (SF) and aging: With MTC and without MTC. The samples were restored in a class I cavity (5mm in the mesio-distal width, 4mm in bucco-lingual and 4mm of depth) aged or not and submitted to BS (n=7) through beams obtained from the restored area. For NL, two beams of each tooth were selected to assess the infiltration of silver nitrate ions. For MA (n=5), the teeth were sectioned parallel and perpendicularly to the occlusal surface and replicas were made in epoxy resin from impressions of the obtained surfaces. The fracture pattern, NL and MA of the external and internal cavity walls were evaluated using scanning electron microscope. The quantitative analysis of NL and MA were performed with the aid of ImageJ software and data obtained from all tests were submitted to two-way ANOVA statistical analysis and Tukey¿s test (? = 0.05). The results showed that TET presented higher values of BS when compared to SF. Z350 and FBF presented BS values statically similar to the others. The most commonly occurred fracture patterns were cohesive in composite or adhesive for all composites, except for FBF not submitted to MTC, which presented a higher percentage of mixed failures. When submitted to MTC, the adhesive failures rate increased for all composites, except for TET, which had its mixed failure rate increased. Regarding NL, the highest values were obtained by TET, differing significantly from the others, which presented similar results among themselves. When not submitted to MTC, the lowest values of internal gap formation were obtained by TET and SF, differing statistically from the others, which did not differ from each other. When submitted to MTC, FBF presented the highest internal gap formation values, followed by Z350 and SF. TET did not differ statistically from FBF and Z350. The highest percentages of external gap formation were obtained by Z350, regardless of being submitted or not to MTC. When not submitted to MTC, the other composites presented the lowest gap formation values and did not differ statistically from each other. When submitted to MTC, TET and SF presented the lowest values. FBF did not differ significantly from the others. The aging of the samples by MTC affected only MA results. It was concluded that bulk-fill composites tested presented similar performance to the conventional nanocomposite and remained stable in face of aging challenges (AU)

FAPESP's process: 15/23201-7 - Evaluation of Marginal Adaptation, Nanoleakage and Bond Strength of Bulk-fill Resin Composites submitted to thermomechanical aging
Grantee:Renata Pereira
Support type: Scholarships in Brazil - Master