Banca de DEFESA: CARLOS EDUARDO DE PAIVA CAMPOS NOGUEIRA SIMAO

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : CARLOS EDUARDO DE PAIVA CAMPOS NOGUEIRA SIMAO
DATE: 30/07/2024
TIME: 14:30
LOCAL: Departamento de Odontologia - Auditório
TITLE:

EVALUATION OF THE SHEAR BOND STRENGTH AND DEGREE OF CONVERSION OF COMPOSITE RESINS USED TO MANUFACTURE ORTHODONTIC ATTACHMENTS SUBMITTED TO DIFFERENT LIGHT-CURING PROTOCOLS

KEY WORDS:

Shear bond strength; Resins; Aesthetic aligners

PAGES: 56
BIG AREA: Ciências da Saúde
AREA: Odontologia
SUBÁREA: Ortodontia
SUMMARY:

Introduction: Fracture or fall of attachments can cause delays in orthodontic treatment, causing loss of effectiveness of planned movement and/or tracking of the aligner. Objective: To evaluate the shear bond strength and degree of conversion of resins used to manufacture orthodontic attachments subjected to different photopolymerization protocols. Methodology: The study sample consisted of 120 bovine lower incisors embedded in acrylic resin and used as a base for making rectangular attachments measuring 03 mm in length, 1.5 mm in width and 1 mm in height. The sample was divided equally into 03 groups corresponding to the resins Opallis Flow^®️, GrandioSO Heavy Flow^®️ and Supreme Flowable Restorative^®️. These groups were subdivided into 04 groups (n=10) according to the polymerization time: 03 seconds (3.200 mW/cm2), 06 seconds (3.200 mW/cm2), 20 seconds (1.000 mW/cm2) and 40 seconds (1.000 mW/cm2). After installing the attachments, the specimens were subjected to shear testing in a universal testing machine (Oswaldo Filizola, São Paulo, Brazil), model AME5k, using a 5kN load cell until fracture occurred. For the conversion degree (GC) test, 60 composite resin specimens were prepared in the shape of rectangular attachments with the same dimensions as the shear test, divided into 03 groups (n=20) according to the aforementioned resins and subdivided into 04 groups (n=05) in relation to the polymerization times studied. The GC was analyzed after 24h of polymerization of the specimens using FT-IR infrared spectroscopy analysis (Perkin Elmer, Waltham, Massachusetts, USA). The data were statistically analyzed using two-way ANOVA and Tukey's post-test. Results: statistical tests indicated that there was a statistical difference for the resin factor (p<.001) and polymerization time (p<.001) with interaction between the factors (p<.001) in relation to shear bond strength. Regarding the degree of conversion, there was a statistical difference for the resin factor (p=.024) and polymerization time (p=.020) with no interaction between the factors. Conclusion: The nanoparticle resin (Supreme Flowable Restorative^®) and the longer polymerization time (40 seconds) showed better mechanical performance in the shear bond strength test and a higher degree of conversion.

COMMITTEE MEMBERS:
Interno - 1009536 - SERGEI GODEIRO FERNANDES RABELO CALDAS
Externo à Instituição - MARCUS VINICIUS NEIVA NUNES DO REGO - UFPI
Externo à Instituição - ALEXANDRE ANTONIO RIBEIRO