Investigou-se a microestrutura e a dureza de uma liga de NiCr utilizada em próteses odontológicas soldadas com brasagem e a laser. Verificou-se que na brasagem o metal base e o cordão de solda apresentaram microestruturas distintas, e que na soldagem a laser identificou-se três regiões: o cordão de solda, a zona afetada pelo calor - ZAC e o metal base. O metal base da liga NiCr apresentou uma microestrutura dendrítica grosseira com uma estrutura eutética interdendrítica, a região da solda por brasagem apresentou uma morfologia dendrítica grosseira com a presença de precipitados e porosidades e na soldagem a laser uma estrutura dendrítica refinada. Estas microestruturas foram condizentes com as energias de soldagem fornecidas em cada processo. Os resultados dos ensaios de tração da solda a laser foram superiores aos obtidos para a solda por brasagem. Para ambos os processos de soldagem a dureza no cordão de solda foi maior do que o metal base, na soldagem a laser a dureza na ZAC foi menor do que no metal base, e sua extensão foi menor que 1mm devido à pequena energia transferida ao metal base. O emprego da soldagem a laser em peças protéticas de pequenas espessuras não deverá causar distorção significativa, sendo promissor na substituição da brasagem nesta aplicação.

Within the limitations of the present study, it was concluded that maxillary sinus elevation with 100% ABB gives predictable results, and that flapless surgery results in less MBL compared with traditional open-flap surgery.

This study aimed to evaluate the survival rates of several external hexagon implants directly connected to zirconia crowns after thermomechanical fatigue. The deformation of the hexagons and the integrity of zirconia crowns were also evaluated. A monolithic zirconia crown (Y-TZP) and four different external hexagon dental implants (n = 10, N = 40) were mounted together and embedded in polyurethane. The specimens were subjected to thermomechanical cycling for 2.5 × 106 cycles, at 3.0 Hz frequency, at 200 N loading. The interface of the implant/zirconia crown system, zirconia crowns integrity before and after cycling, and the implant hexagon surface were evaluated under stereomicroscopy and SEM. A nanohardness analysis was performed to verify the hardness of zirconia and implants. Statistical analysis was performed using the Kaplan-Meier test, Multi-Sample Survival Tests, Logrank Test, (p = 0.05). The data did not show significant differences in the survival rates of different implant groups. However, some crowns presented fractures (16.67%) and the external hexagon region of the implants presented plastic deformations (100%). During chewing simulation, the interface between titanium implant and zirconia abutment can promote plastic deformation in the metal and surface defects in the ceramic. In addition, the types of interface defects can be affected by the external hexagon design.

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O objetivo deste trabalho é avaliar a correlação entre a altura óssea medida em radiografias panorâmicas e tomografias computadorizadas para a avaliação pré-operatória de implantes osseointegrados. Cinqüenta sítios na região do forame mentual de pacientes que previamente realizaram tomografia computadorizada e radiografia panorâmica para planejamento de implantes osseointegrados nas regiões posteriores da mandíbula foram analisados. A comparação entre a TC e a radiografia panorâmica apresentou uma concordância moderada, sendo que a TC sistematicamente apresentou valores menores que as medições realizadas na radiografia panorâmica, sendo essa diferença (1,6 a 1,7mm) estatisticamente significante (p<0,0001). Os autores sugerem a utilização de uma margem de segurança de 2mm na região de forame mentual, após a compensação da magnificação da imagem, quando for utilizada a radiografia panorâmica.

Objective: To analyze and compare the effectiveness of two methods designed for the assessment of esthetic impairment in patients with missing teeth. Material and Methods: Two methods were addressed in this study: 7-level scale (7LS) and AIPE-Odonto/Brasil. Both tools are designed to assess esthetic dental impairment in civil and criminal Courts. One-hundred and thirteen dentists used the tools to assess dental esthetic impairment in four mock cases (one male and three females). The outcomes of their analyses were compared with pre-established gold-standard scores. Chi-square test was used to investigate the influence of dentists' sex, age, time of experience and forensic knowledge with their outcomes. Results: Dentists' outcomes were closer to the expected gold-standard scores when AIPE-Odonto/Brasil was used compared to 7LS (p < 0.05). Dentists' sex, time of experience and forensic knowledge were significantly associated with the scores obtained with both tools (p < 0.05). Conclusions: Comparatively, AIPE-Odonto/Brasil was more effective for the assessment of esthetic dental impairment involving missing teeth compared to the 7LS.

The use of digital technology is increasing rapidly in modern dentistry. However, there is still not enough data in the literature regarding the manufacture of milled frameworks on implant-supported prosthesis. Purpose: To assess the stress caused on dental implants by milled frameworks of different sizes made through digital workflow and to compare two types of scanners. Methods: An edentulous model of a maxilla was created through 3D printing, where six equidistant implants were installed with a 50Ncm torque. Over each implant was installed a 5.5mm mini conical abutment with a 32Ncm torque. Over these abutments, two types of scanning were performed: intraoral scanners (IOS) and laboratory scanners (LS), from which each framework was designed and milled from titanium discs. These frameworks were made over two, four and six implants, simulating different clinical situations. To analyze the deformation, two strain gages were attached to the abutment surfaces, on the buccal and mesial surfaces. Results were analyzed using a paired Student’s t-test, with significance level of 0.005. The passivity was evaluated by an experienced operator. Results: LS scanners had the lowest deformation, when compared to the IOS. The greater the distance between the implants, the higher the deformation. In frameworks on 4 implants, the deformation was greater, as it was the distance between the implants. The groups on 2 implants showed the least strain (p < 0.005). All frameworks were considered passive, as they all fit the passivity criteria. Conclusions: All scanning techniques reported are reliable. The milled frameworks are passive and accurate, with very little deformation, and they can be safely supported by implants, without bone resorption.

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