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Purpose: To evaluate the effect of irradiation with an optical-fiber device on the bond strength of hollow and partially opaque intraradicular posts. Materials and Methods: An optical-fiber accessory tip was attached to a light-curing unit to emit light through the central hollow of an experimental fiberglass post. The samples were divided into 4 groups (n=80) according to the protocol (Variolink N [light cured] or Multilink N [dual-curing luting material]) and the light-curing mode (performed con ventionally or with the optical fiber): GF: light-curing luting material; GFF: light-curing luting material and optical fiber; GD: dual-curing luting material; GDF: dual-curing luting material and optical fiber. The samples were tested immedi ately or after aging. Push-out bond strength, failure mode, degree of conversion (DC, assessed at the peak of 1750cm-1), and stress distribution by finite element analysis were performed. Quantitative data were analyzed using 3-way ANOVA (luting material x light curing x depth) and 2-way ANOVA (aging x luting material), followed by Tukey’s test. Results Bond strength was significantly affected by the luting material protocol (p

The Covid-19 is a global health threatening pandemic, so dental surgeons need to look for strategies to perform dental care safely for the patient, the dental professional himself, and the dental team. The goal is to design strategies to optimize dental impression practice during the Covid-19 pandemic. The strategies that optimize dental impression practice during the pandemic are to adopt the digital fingerprint workflow. If necessary, a conventional impression technique that favors the professional’s performance, select the impression material that is easy to decontaminate and affinity for the professional; the plaster leak must be performed still inside the dental office, and then the disinfection of the plaster model must be previously sent to the prosthesis laboratory. RESUMO A Covid-19 é uma pandemia que ameaça de saúde global, assim os cirurgiões-dentistas necessitam buscar estratégias para realizar o atendimento odontológico de forma segura para paciente, próprio profissional e equipe odontológica. Objetiva-se traçar estratégias que otimize a prática da impressão dental durante a pandemia da Covid-19. As estratégias que otimizam a prática da impressão dental, durante a pandemia, são adotar o fluxo de trabalho digital através da impressão digital. Caso necessário a impressão convencional, uma técnica de impressão que favoreça o desempenho do profissional, selecionar o material de moldagem de fácil descontaminação e de afinidade pelo profissional; o vazamento do gesso deve ser realizado ainda dentro do consultório odontológico, e em seguida a desinfecção do modelo em gesso previamente ser enviado ao laboratório de prótese.

Made available in DSpace on 2022-05-01T09:31:04Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-01-01 Purpose: Using the microshear bond strength (pSBS) test, this study investigated the bond strength between a hybrid ceramic and the extrinsic characterization layer after different ceramic surface treatments. Materials and Methods: Hybrid ceramic blocks (Vita Enamic, Vita Zahnfabrik) were sectioned and randomly divided into 4 groups (N = 120) according to the surface treatment and aging (n = 15): P: polishing; E: acid etching with HF; A: aluminum oxide blasting; S: self-etching ceramic primer. The specimens were silanized, then cylinders of light-curing characterization material (Vita Enamic Stain, 1.6 mm diameter x 2 mm height) were fabricated, followed by glazing. The specimens were subsequently immersed in distilled water for 24 h and subjected to the pSBS test using a universal testing machine (load cell 0.5 mm/min, 50 kgf) or tested after thermocycling for 10,000 cycles in water (5°C-55°C). After treatment, the specimen surfaces were analyzed using SEM, with failure types defined as adhesive, predominantly adhesive, or cohesive. The data were analyzed by two-way ANOVA followed by Tukey's test (p < 0.05). Results: The most frequent failure type was predominantly adhesive between ceramic and the characterization layer. There were statistically significant differences between the surface treatments (p < 0.05). Thermocycling did not lead to statistically signifcant different results (p > 0.05). For groups P and A, a sharp decrease in SBS was observed. Conclusion: The absence of surface treatment drastically reduced the microshear bond strength between the ceramic and the characterization layer. Conditioning with 5% hydrofluoric acid for 60 s is the most suitable treatment for adhesion of the characterization layer to hybrid ceramic. PhD Student Postgraduate Program in Restorative Dentistry Sao Paulo State University (UNESP) Institute of Science and Technology MSc Student Postgraduate Program in Restorative Dentistry Sao Paulo State University (UNESP) Institute of Science and Technology Professor Postgraduate Program in Restorative Dentistry Sao Paulo State University (UNESP) Institute of Science and Technology Professor Department of Dentistry University of Taubaté (UNITAU) PhD Student Postgraduate Program in Restorative Dentistry Sao Paulo State University (UNESP) Institute of Science and Technology MSc Student Postgraduate Program in Restorative Dentistry Sao Paulo State University (UNESP) Institute of Science and Technology Professor Postgraduate Program in Restorative Dentistry Sao Paulo State University (UNESP) Institute of Science and Technology

Submitted by Manassés Tercio Vieira Grangeiro (manasses.grangeiro@unesp.br) on 2020-03-09T20:51:44Z No. of bitstreams: 1 dissertação manasses 09 03 2020 arquivo final.pdf: 2253516 bytes, checksum: 02c7ecfe8157a9eb1105b01c6d21bb79 (MD5) Approved for entry into archive by Silvana Alvarez null (silvana@ict.unesp.br) on 2020-03-09T21:58:01Z (GMT) No. of bitstreams: 1 grangeiro_mtv_me_sjc.pdf: 2253516 bytes, checksum: 02c7ecfe8157a9eb1105b01c6d21bb79 (MD5) Made available in DSpace on 2020-03-09T21:58:01Z (GMT). No. of bitstreams: 1 grangeiro_mtv_me_sjc.pdf: 2253516 bytes, checksum: 02c7ecfe8157a9eb1105b01c6d21bb79 (MD5) Previous issue date: 2020-02-03 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Este estudo avaliou a resistência ao desgaste fisiológico da camada de caracterização aplicada sobre cerâmica híbrida com diferentes tratamentos de superfície, em função do antagonista. Foram confeccionados 160 discos (12 mm de diâmetro, 1,2 mm de espessura) de cerâmica híbrida com polímero (Vita Enamic, Vita Zhanfabrick, Bad Säckingen, Alemanha) e foram polidos com lixas de carbeto de silício até # 1200 e divididas aleatoriamente em grupos experimentais (n = 10), de acordo com o tratamento da superfície da cerâmica previamente à caracterização e a finalização da cerâmica com camada de glaze ou não (P: amostras polidas sem caracterização; PG: amostras polidas, finalização com glaze; C: pigmentação convencional; CG: pigmentação convencional, finalização com glaze; J: jateamento; JG: jateamento, finalização com glaze; S: uso de silano autocondicionante; SG: uso de silano autocondicionante, finalização com glaze). Metade dos espécimes foram submetidos à simulação do desgaste fisiológico com aplicadores de esteatita, enquanto para a outra metade com aplicadores de cerâmica híbrida. Com auxílio de perfilômetro de contato foram analisados parâmetros de rugosidade. A rugosidade média Ra e espaçamento RSm foram analisados pela estatística ANOVA 3 fatores (tratamento de superfície x presença de glaze x antagonista), seguido por teste de Tukey com a=5%. Houve influência da interação dos 3 fatores na rugosidade média (Ra) da cerâmica PIC (p=0,000) e na interação 2 fatores (tratamento de superfície x presença glaze) na rugosidade de espaçamento RSm da cerâmica PIC (p=0,011). A cerâmica híbrida necessita de um tratamento de superfície para que seja realizada a caracterização extrínseca. A aplicação do glaze após a caracterização reduz a rugosidade superficial e o potencial de desgaste do antagonista. This study evaluated the resistance to physiological wear of the characterization layer applied over hybrid ceramic with different surface treatments, with different antagonists. One hundred and sixty discs were confectioned (12 mm of diameter, 1.2 mm of thickness) of hybrid ceramic with polymer (Vita Enamic, Vita Zhanfabrick, Bad Säckingen, Germany) and were polished with silicon carbide paper # 1200 and randomly divided into experimental groups (n = 10), according to the surface treatment previously to the characterization and finishing of the ceramic either with a glaze layer or not (P: samples polished without characterization; PG: polished samples with glaze finishing; C: conventional pigmentation; CG: conventional pigmentation finishing with glaze; J: sandblasting; JG: sandblasting, finishing with glaze; S: use of self-etching silane; SG: use of self-etching silane, finishing with glaze). Half of the specimens were submitted to simulation of physiological wear with steatite applicators, meanwhile for the other half, applicators of hybrid ceramic were used. With the aid of a contact perfilometer, roughness parameters were analyzed. The mean roughness Ra and spacing roughness RSm were statistically analyzed by 3-way ANOVA (surface treatment x glaze presence x antagonist), followed by Tukey (a= 5%). There was influence of interaction of the three factors in mean roughness (Ra) of hybrid ceramic (p=0.000) and in the interaction of two factors (surface treatment x glaze presence) in the spacing roughness RSm of the hybrid ceramic (p=0.011). Hybrid ceramic require a surface treatment for extrinsic characterization. Glaze application after characterization decreases surface roughness and wear potential of the antagonist. Fapesp nº 2018/04726-0