Isabelle Helena Gurgel de Carvalho1, Nathalia Ramos da Silva1, Taciana Emília Leite Vila-Nova2, Leopoldina de Fatima Dantas de Almeida3, Aretha Heitor Veríssimo1, Renata Marques de Melo4, Yu Zhang5, Rodrigo Othávio de Assunção E Souza6. 1. Health Science Center, Department of Dentistry, Division of Prosthodontics, Federal University of Rio Grande Do Norte (UFRN), Avenida Senador Salgado Filho, nº 1787, Lagoa Nova, Natal, RN, 59056-000, Brazil. 2. Department of Dentistry, University of Pernambuco (UPE), Av. Governador Agamenon Magalhães, S/N- Santo Amaro, Recife, PE, 50100-010, Brazil. 3. Department of Dentistry, Federal University of Paraíba (UFPB), Campus I - Cidade Universitária, João Pessoa, PB, 58033-455 , Brazil. 4. Department of Dental Materials and Prosthodontics, Institute of Science and Technology, Univ Estadual Paulista - UNESP, Av. Eng. Francisco Jose Longo, 777, Sao Jose dos Campos, SP, 12245-000, Brazil. 5. School of Dental Medicine, Department of Preventive and Restorative Sciences, University of Pennsylvania, 240 S. 40th Street, Philadelphia, PA, 19104, USA. 6. Health Science Center, Department of Dentistry, Division of Prosthodontics, Federal University of Rio Grande Do Norte (UFRN), Avenida Senador Salgado Filho, nº 1787, Lagoa Nova, Natal, RN, 59056-000, Brazil. rodrigoothavio@gmail.com.
Abstract
OBJECTIVE: To investigate the influence of different finishing/polishing techniques and in situ aging on the flexural strength (σ), surface roughness, and Candida albicans adherence of 5 mol% yttria-stabilized zirconia (ultratranslucent zirconia). MATERIALS AND METHODS: A total of 120 zirconia bars (Prettau Anterior, Zirkonzahn) with dimensions of 8 × 2 × 0.5 mm were divided into 8 groups (n = 15) according to two factors: "in situ aging" (non-aged and aged (A)) and "finishing/polishing" (control (C), diamond rubber polishing (R), coarse grit diamond bur abrasion (B), and coarse grit diamond bur abrasion + diamond rubber polishing (BR)). Half of the samples from each group were subjected to a 60-day in situ aging by fixing the bars into cavities prepared in the posterior region of the base of complete or partial dentures of 15 patients. The samples were then subjected to the mini flexural (σ) test (1 mm/min). A total of 40 zirconia blocks (5 × 5 × 2 mm) were prepared and subjected to roughness (Ra) analyses and fungal adherence and complementary analyses (X-ray diffraction (XRD) and scanning electron microscopy (SEM)). The data of mean σ (MPa) and roughness Ra (μm) were statistically analyzed by two-way and one-way ANOVA, respectively, and Tukey's test. The Weibull analysis was performed for σ data. The fungal adhesion (Log CFU/mL) data were analyzed by Kruskal-Wallis tests. RESULTS: For flexural resistance, the "finishing/polishing" factor was statistically significant (P = 0.0001); however, the "in situ aging" factor (P = 0.4458) was not significant. The non-aged (507.3 ± 115.7 MPa) and aged (487.6 ± 118.4 MPa) rubber polishing groups exhibited higher mean σ than the other techniques. The non-aged (260.2 ± 43.3 MPa) and aged (270.1 ± 48.8 MPa) bur abrasion groups presented lower σ. The coarse-grit diamond bur abrasion group (1.82 ± 0.61 µm) presented the highest roughness value (P = 0.001). Cell adhesion was not different among groups (P = 0.053). Group B presented the most irregular surface and the highest roughness Ra of 0.61 m. CONCLUSIONS: The finishing of ultratranslucent zirconia might be preferably done with a diamond rubber polisher. Moreover, the protocols used did not interfere with Candida albicans adhesion. CLINICAL RELEVANCE: Coarse-grit diamond burs might be avoided for finishing ultratranslucent monolithic zirconia, which might be preferably performed with a diamond rubber polisher.
OBJECTIVE: To investigate the influence of different finishing/polishing techniques and in situ aging on the flexural strength (σ), surface roughness, and Candida albicans adherence of 5 mol% yttria-stabilized zirconia (ultratranslucent zirconia). MATERIALS AND METHODS: A total of 120 zirconia bars (Prettau Anterior, Zirkonzahn) with dimensions of 8 × 2 × 0.5 mm were divided into 8 groups (n = 15) according to two factors: "in situ aging" (non-aged and aged (A)) and "finishing/polishing" (control (C), diamond rubber polishing (R), coarse grit diamond bur abrasion (B), and coarse grit diamond bur abrasion + diamond rubber polishing (BR)). Half of the samples from each group were subjected to a 60-day in situ aging by fixing the bars into cavities prepared in the posterior region of the base of complete or partial dentures of 15 patients. The samples were then subjected to the mini flexural (σ) test (1 mm/min). A total of 40 zirconia blocks (5 × 5 × 2 mm) were prepared and subjected to roughness (Ra) analyses and fungal adherence and complementary analyses (X-ray diffraction (XRD) and scanning electron microscopy (SEM)). The data of mean σ (MPa) and roughness Ra (μm) were statistically analyzed by two-way and one-way ANOVA, respectively, and Tukey's test. The Weibull analysis was performed for σ data. The fungal adhesion (Log CFU/mL) data were analyzed by Kruskal-Wallis tests. RESULTS: For flexural resistance, the "finishing/polishing" factor was statistically significant (P = 0.0001); however, the "in situ aging" factor (P = 0.4458) was not significant. The non-aged (507.3 ± 115.7 MPa) and aged (487.6 ± 118.4 MPa) rubber polishing groups exhibited higher mean σ than the other techniques. The non-aged (260.2 ± 43.3 MPa) and aged (270.1 ± 48.8 MPa) bur abrasion groups presented lower σ. The coarse-grit diamond bur abrasion group (1.82 ± 0.61 µm) presented the highest roughness value (P = 0.001). Cell adhesion was not different among groups (P = 0.053). Group B presented the most irregular surface and the highest roughness Ra of 0.61 m. CONCLUSIONS: The finishing of ultratranslucent zirconia might be preferably done with a diamond rubber polisher. Moreover, the protocols used did not interfere with Candida albicans adhesion. CLINICAL RELEVANCE: Coarse-grit diamond burs might be avoided for finishing ultratranslucent monolithic zirconia, which might be preferably performed with a diamond rubber polisher.
Authors: Michele Carrabba; Andrew J Keeling; Aziz Aziz; Alessandro Vichi; Riccardo Fabian Fonzar; David Wood; Marco Ferrari Journal: J Dent Date: 2017-03-06 Impact factor: 4.379
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