Assessment in vitro of brushing on dental surface roughness alteration by laser interferometry

Noncarious cervical lesions (NCCLs) are considered to be of multifactorial origin, normally associated with inadequate brushing. This study assessed the influence in vitro of simulated brushing on NCCL formation. Fifteen human premolars were submitted to brushing in the cementoenamel junction region, using hard-, medium- and soft-bristled brushes associated with a toothpaste of medium abrasiveness under a 200 g load, at a speed of 356 rpm for 100 minutes. The surface topography of the region was analyzed before and after brushing, by means of a laser interferometer, using "cut-off" values of 0.25 and considering roughness values in mm. The initial roughness (mm) results for dentin (D / bristle consistency: 1 - soft, 2 - medium and 3 - hard) were as follows: (D1) 1.25 ± 0.45; (D2) 1.12 ± 0.44; (D3) 1.05 ± 0.41. For enamel (E / bristle consistency: 1 - soft, 2 - medium and 3 - hard), the initial results were: (E1) 1.18 ± 0.35; (E2) 1.32 ± 0.25; (E3) 1.50 ± 0.38. After brushing, the following were the values for dentin: (D1) 2.32 ± 1.99; (D2) 3.30 ± 0.96; (D3) Over 500. For enamel, the values after brushing were: (E1) 1.37 ± 0.31; (E2) 2.15 ± 0.90; (E3) 1.22 ± 0.47. Based on the results of the ANOVA and Tukey statistical analyses (a = .05) it was concluded that soft, medium and hard brushes are not capable of abrading enamel, whereas dentin showed changes in surface roughness by the action of medium- and hard-bristled brushes.FAPEMI

Effect of cavity preparation design and ceramic type on the stress distribution, strain and fracture resistance of CAD/CAM onlays in molars

Objective: This study aimed to evaluate the effect of the cavity preparation and ceramic type on the stress distribution, tooth strain, fracture resistance and fracture mode of human molar teeth restored with onlays. Material and Methods: Forty-eight molars were divided into four groups (n=12) with assorted combinations of two study factors: BL- conventional onlay preparation with boxes made from leucite ceramic (IPS-Empress CAD, Ivoclar Vivadent); NBL- conservative onlay preparation without boxes made from leucite ceramic; BD- conventional onlay preparation with boxes made from lithium disilicate glass ceramic (IPS e.max CAD, Ivoclar Vivadent); NBL- conservative onlay preparation with boxes made from lithium disilicate glass ceramic cuspal deformation (µS) was measured at 100 N and at maximum fracture load using strain gauge. Fracture resistance (N) was measured using a compression test, and the fracture mode was recorded. Finite element analysis was used to evaluate the stress distribution by modified von Mises stress criteria. The tooth strain and fracture resistance data were analyzed using the Tukey test and two-way ANOVA, and the fracture mode was analyzed by the chi-square test (α=0.05). Results: The leucite ceramic resulted in higher tooth deformation at 100 N and lower tooth deformation at the maximum fracture load than the lithium disilicate ceramic (P<0.001). The lithium disilicate ceramic exhibited higher fracture resistance than the leucite ceramic (P<0.001). The conservative onlay resulted in higher fracture strength for lithium disilicate ceramic. Finite element analysis results showed the conventional cavity preparation resulted in higher stress concentration in the ceramic restoration and remaining tooth than the conservative onlay preparation. The conservative onlays exhibited increased fracture resistance, reduced stress concentration and more favorable fracture modes. Conclusion: Molars restored with lithium disilicate CAD-CAM ceramic onlays exhibited higher fracture resistance than molars restored with leucite CAD-CAM ceramic onlays

Memorial descritivo Célio Jesus do Prado

CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível SuperiorEste memorial descritivo foi elaborado para cumprir com as exigências da Resolução 03/2017, 04/2018 e 05/2018, do Conselho Diretor, que regulamentam a avaliação docente no que se refere à Progressão, à Promoção e à Aceleração da Promoção nas Carreiras de Magistérios Superior da Universidade Federal de Uberlândia. Ele refere-se as minhas atividades profissionais, relacionadas à Faculdade de Odontologia da Universidade Federal de Uberlândia, sendo um dos requisitos para se obter a Promoção de Professor Associado para Professor Titular. O relato a seguir tenta ser cronologicamente coerente, mostrando a evolução como professor, à medida que a Instituição evoluiu, principalmente no que concerne à pesquisa. Nestes 26 anos de carreira docente cumpri as metas profissionais pertinentes ao cargo de professor relativas ao ensino, pesquisa, extensão e atividades administrativas e também cumprido o prazo mínimo como professor associado 4. Desta forma, este memorial descritivo tem como objetivo apresentar a minha trajetória acadêmica até a presente data, para avaliação e, possível, promoção para progredir na carreira docente de Professor Associado 4 para Professor Titular nível E, na Carreira do Magistério Superior da Universidade Federal de Uberlândia

Masticatory Function of Subjects Rehabilitated with Conventional Complete Denture

Objective: Evaluate masticatory function of subjects rehabilitated with conventional complete denture, considered adequate or good (index of Kapur), by means of objective and subjective tests and to verify influence of quality and denture time use. Method: Masticatory performance tests (MP), using test food Optocal, had been carried through with 20 and 40 chewing strokes in 21 subjects with complete denture (group CD) and 15 with natural dentition (group ND). Masticatory performance index was taken by means of the calculation of the Average Geometric Diameter of chewed and sifted particles. Results: After analysis statistics (Tukey b, p<0.05), observed that group CD obtainable 12% and 31% of the performance reached for group ND subjects, after 20 and 40 strokes, respectively, being that literature quantifies masticatory performance from 20% to 30% of the natural dentition. Statistical significant differences (t-test student, p<0.05) between MP and masticatory ability had not been verified, as well as denture quality of group CD. In relation to denture use period, users with more than six months had obtainable better resulted, possibly for being more adapts to the denture. Conclusion: In the limit of this study, it could be possible conclude that complete dentures users considered adequate or good had improved its MP after use six months. Standing out that with 20 strokes, in test food related, the result (12%) was worst to in literature described

Effect of cavity preparation design and ceramic type on the stress distribution, strain and fracture resistance of CAD/CAM onlays in molars

Abstract Objective This study aimed to evaluate the effect of the cavity preparation and ceramic type on the stress distribution, tooth strain, fracture resistance and fracture mode of human molar teeth restored with onlays. Material and Methods Forty-eight molars were divided into four groups (n=12) with assorted combinations of two study factors: BL- conventional onlay preparation with boxes made from leucite ceramic (IPS-Empress CAD, Ivoclar Vivadent); NBL- conservative onlay preparation without boxes made from leucite ceramic; BD- conventional onlay preparation with boxes made from lithium disilicate glass ceramic (IPS e.max CAD, Ivoclar Vivadent); NBL- conservative onlay preparation with boxes made from lithium disilicate glass ceramic cuspal deformation (µS) was measured at 100 N and at maximum fracture load using strain gauge. Fracture resistance (N) was measured using a compression test, and the fracture mode was recorded. Finite element analysis was used to evaluate the stress distribution by modified von Mises stress criteria. The tooth strain and fracture resistance data were analyzed using the Tukey test and two-way ANOVA, and the fracture mode was analyzed by the chi-square test (α=0.05). Results The leucite ceramic resulted in higher tooth deformation at 100 N and lower tooth deformation at the maximum fracture load than the lithium disilicate ceramic (P<0.001). The lithium disilicate ceramic exhibited higher fracture resistance than the leucite ceramic (P<0.001). The conservative onlay resulted in higher fracture strength for lithium disilicate ceramic. Finite element analysis results showed the conventional cavity preparation resulted in higher stress concentration in the ceramic restoration and remaining tooth than the conservative onlay preparation. The conservative onlays exhibited increased fracture resistance, reduced stress concentration and more favorable fracture modes. Conclusion Molars restored with lithium disilicate CAD-CAM ceramic onlays exhibited higher fracture resistance than molars restored with leucite CAD-CAM ceramic onlays

Computer-Aided Design/Computer-Aided Manufacturing of Customized Abutment for Rehabilitating a Malpositioned Implant Using Digital Flow: A Case Report

This study presented a rehabilitation option for malpositioned implants; this involved obtaining their position and inclination through intraoral scanning, and producing a customized abutment with CAD/CAM technology. The patient in this case report presented a root fracture in tooth 21 and was subjected to extraction, implant installation, and immediate provisional prosthesis. The implant was installed with a distal inclination due to anatomical limitations. After osseointegration, an intraoral scanning transfer provided a digital model (file extension .stl), which reproduced the implant’s position and inclination. Then, the file was sent so that a customized abutment (CAD/CAM) could be manufactured, promoting the final rehabilitation of the case; this allowed for good hygiene, load distribution in the dynamic interocclusal relationship, and favorable esthetics, whereas many would otherwise recommend implant removal. The result presented lower costs, a shorter time frame, and a lower morbidity for the patient

Microtensile Bond Strength Of Methacrylate And Silorane Resins To Enamel And Dentin.

The aim of this study was to evaluate the microtensile bond strength (µTBS) of two substrates (enamel and dentin) considering two study factors: type of composite resin [methacrylate-based (Filtek Supreme) or silorane-based (Filtek LS)] and aging time (24 h or 3 months). Twenty human molars were selected and divided into 2 groups (n=10) considering two dental substrates, enamel or dentin. The enamel and dentin of each tooth was divided into two halves separated by a glass plate. Each tooth was restored using both tested composite resins following the manufacturer's instructions. The samples were sectioned, producing 4 sticks for each composite resin. Half of them were tested after 24 h and half after 3 months. µTBS testing was carried out at 0.05 mm/s. Data were analyzed by three-way ANOVA and Tukey's HSD tests at α=0.05. Significant differences between composite resins and substrates were found (p<0.05), but no statistically significant difference was found for aging time and interactions among study factors. The methacrylate-based resin showed higher µTBS than the silorane-based resin. The µTBS for enamel was significantly higher than for dentin, irrespective of the composite resin and storage time. Three months of storage was not sufficient time to cause degradation of the bonding interaction of either of the composite resins to enamel and dentin.25327-3