Use of Acid for Oxide Layer Removal of Overcast UCLA Abutments: Influence on Fit and Roughness.

PURPOSE: The objective of this study was to evaluate the influence of the oxide layer removal procedure using acid on the roughness and internal fit of overcast universal castable long abutments (UCLAs) for a taper connection. MATERIALS AND METHODS: For this, maxillary first premolars were waxed on the plastic sleeve of 15 UCLAs with a premachined interface. The specimens were overcast using the NiCr alloy, and the frameworks were randomly distributed to undergo one of two different oxide layer removal methods: blasting with 100-µm particles of aluminum oxide at 0.60-MPa pressure or bathing for 5 hours in 0.5% hydrofluoric acid. The surface roughness was evaluated by a light interferometer at the subcritical contour of each abutment. Next, the frameworks were attached to the respective analogs for internal fit evaluation. The central cross section of each assembly was exposed, and three regions were visualized by scanning electron microscopy (SEM): taper interface, axial wall, and index region. The premachined base was used as the control. The groups were compared using analysis of variance (ANOVA) and Tukey post hoc test (α = .05). RESULTS: The results showed that acid bathing produced intermediary roughness between premachined and blasted surfaces (P < .05). SEM images showed a sealed interface at the taper region of all groups, despite some irregularities after alumina blasting. Increased discrepancies at the axial wall and index region were found after the alumina blasting procedure (P < .05). CONCLUSION: It was concluded that acid bathing should be used, instead of blasting to remove the oxide layer, to produce a better fit and smoother surface on UCLAs.

A comparison between visual, intraoral scanner, and spectrophotometer shade matching: A clinical study.

STATEMENT OF PROBLEM: Visual shade matching is subjective and a cause of concern for clinicians. Different measurement devices have been developed to assist in tooth color selection and to achieve better esthetic results. However, consensus is lacking as to which method of tooth shade selection provides more predictable results. PURPOSE: The purpose of this clinical study was to compare the reliability of different visual and instrumental methods for dental shade matching. MATERIAL AND METHODS: Visual shade matching was performed by 3 experienced clinicians using 2 different shade guides (VITA Classical A1-D4 and VITA Toothguide 3D-MASTER with 29 tabs; VITA Zahnfabrik) with and without the aid of a light-correcting device (Smile Lite; Smile Line). An intraoral scanner (TRIOS; 3Shape A/S) and a spectrophotometer (VITA Easyshade Advance 4.0; VITA Zahnfabrik) were also used for color shade matching. The instrumental methods were repeated 3 times to determine repeatability. Shade-matching sessions for each method were performed under controlled lighting on the middle third of the maxillary right central incisor of 28 participants. The Fleiss' kappa statistical test was used to assess the reliability of each method. The weighted kappa statistical test was used to assess the agreement between the shades matched by different methods (α=.05). RESULTS: Instrumental methods were more accurate than visual methods. The best performance was found for the intraoral scanner configured for the 3D-MASTER scale (Fleiss' kappa value of .874) and for the spectrophotometer configured for the VITA Classical scale (Fleiss' kappa value of .805). The best visual shade-matching method was the VITA Classical scale associated with the light-correcting device (Fleiss' kappa value of .322). The Classical scale without the light-correcting device showed the poorest reliability (Fleiss' kappa value of .177) (P<.05). CONCLUSIONS: Instrumental methods for color shade matching were more reliable than the visual methods tested.

Predictable Outcomes with Porcelain Laminate Veneers: A Clinical Report.

This clinical report describes how to achieve predictable outcomes for anterior teeth esthetic restorations with porcelain laminate veneers by associating the digital planning and design of the restoration with interim restorations. The previous digital smile design of the restoration eliminates the communication barrier with the patient and assists the clinician throughout patient treatment. Interim restorations (diagnostic mock-ups) further enhance communication with the patient and prevent unnecessary tooth reduction for conservative tooth preparation. Adequate communication between patient and clinician contributes to successful definitive restorations and patient satisfaction with the final esthetic outcome.

Planejamento e fabricação de restaurações implantossuportadas com processos odontológicos digitais / Digital planning and fabrication of implant-supported restorations

A Odontologia digital proporciona ao clínico novas possibilidades para planejar e fabricar as restaurações utilizadas na clínica diária. O planejamento virtual das restaurações é uma excelente ferramenta para prever o resultado final do tratamento, proporcionando maior segurança para o clínico e para o paciente. Este trabalho teve como objetivo descrever os passos do fluxo de trabalho necessário para a moldagem intraoral digital, planejamento virtual da restauração e fabricação pelo método CAD/CAM com o auxílio de um caso clínico em que o primeiro pré-molar superior foi restaurado. As arcadas digitalizadas foram utilizadas para planejar virtualmente as dimensões e os aspectos oclusais e estéticos da restauração, para a fabricação de modelo fresado das arcadas dentárias e para a posterior confecção da restauração com o auxílio do método CAD/CAM. Devido à digitalização de todos os passos até a confecção da prótese, a comunicação com o paciente foi facilitada, possibilitando a visualização adequada do proposto para a restauração. Pôde-se concluir que, uma vez dominado o uso da tecnologia digital, as restaurações podem ser consistentemente planejadas e fabricadas com o auxílio dos avançados métodos de fabricação atualmente disponíveis, levando a resultados altamente previsíveis e satisfatórios clinicamente.

Digital dentistry allows clinicians to design and fabricate predictable restorations for daily clinics. Virtual design of the restoration is an excellent tool to predict the fi nal outcome of the rehabilitation by the clinician and the patient. This study will describe the workflow for digital fabrication of dental restorations, including the digital intraoral impression, virtual design, and CAD/CAM fabrication of the restoration of a first maxillary premolar. The digital tooth arches were used to virtually plan the dimensions and the occlusal and esthetic aspects of the restoration. Milled dental models were also fabricated. Patient communication was improved by using the virtual design of the final restoration. It can be concluded that digital dentistry can allow the fabrication of consistent and highly predictable dental restorations.

Nova técnica L-PRF segmentada para procedimentos regenerativos e implantares / A new L-PRF segmented technique for regenerative and dental implant procedures

Este trabalho teve o objetivo de relatar o caso clínico de paciente com rebordo em lâmina de faca na região anterior (incisivo lateral), tratado com a combinação de enxerto autógeno particulado associado a enxerto alógeno derivado de osso bovino inorgânico. Membranas de L-PRF e malha de titânio foram utilizadas para proteger e estabilizar o enxerto. O paciente teve o implante instalado na região seis meses após a realização do enxerto ósseo. No caso clínico apresentado, foram associadas as vantagens da L-PRF como matriz de suporte para as proteínas morfogenéticas ósseas (BMPs) na região em contato com o rebordo reabsorvido, combinadas ao osso particulado autógeno e ao osso bovino inorgânico. Também foram utilizadas membranas de L-PRF sobre a malha de titânio, no intuito de servirem como curativos de fibrina, contribuindo para acelerar e melhorar o processo de cicatrização da ferida cirúrgica. O uso da L-PRF para a resolução deste caso clínico indicou melhora e aceleração da cicatrização da ferida cirúrgica, maior espessura gengival e auxílio na maturação do enxerto ósseo, o que contribuiu para o resultado estético final dos tecidos peri-implantares.

This study aims to report a case of a patient with a “knife-edged” ridge in the anterior region (lateral incisor) that was treated with a combined graft of particulated autogenous bone and anorganic bovine mineral bone. L-PRF membranes and a titanium mesh were used to protect and stabilize the graft. The patient had a threaded implant installed six months after the grafting procedures. This clinical report associated the advantages of L-PRF as a matrix scaffold for bone morphogenetic proteins (BMP) in the graft region in contact with the bone ridge and combined with particulated autogenous bone and anorganic bovine bone-derived mineral grafts. L-PRF membranes were also used as fibrin bandages, aiming to improve the healing process. The use of L-PRF in the present clinical report suggested an improved graft healing, increased gingival width and aided the bone maturing process, which finally contributed to the esthetic outcome of the peri-implant tissues.

Uso do sistema MK1 em overdenture implantossuportada para reabilitação do suporte labial deficiente / Restoring deficient upper lip support with implant-supported overdentures associated with the MK1 attachment system

A reabilitação com implantes da maxila desdentada é muitas vezes dificultada pela reabsorção óssea excessiva em sua região anterior, após a perda dos dentes, levando a um suporte labial deficiente. As overdentures são recomendadas para estes casos pela presença da flange vestibular, que se estende até o fundo de vestíbulo labial e proporciona maior suporte ao lábio do paciente. O objetivo deste estudo foi apresentar o caso clínico de um paciente reabilitado com overdenture suportada por implantes e fixada pelo sistema de encaixes MK1. Durante exame clínico inicial, foi identificada a ausência de suporte labial para proporcionar a estética labial necessária para a resolução do caso com próteses fixas totais convencionais suportadas por implantes (prótese/protocolo). A overdenture suportada por implantes dentários permitiu o restabelecimento do suporte labial perdido pelo paciente, contribuindo para a boa estética facial final do caso e o restabelecimento da função mastigatória. O sistema de encaixes MK1 também proporcionou o conforto de uma prótese fixa, sem cobertura palatina, mas com fácil dispositivo para sua remoção, facilitando a higienização adequada.

Severe bone resorption of the edentulous anterior maxilla leads to deficient upper lip support and difficult implant rehabilitation. Overdentures are recommended because of the presence of the anterior flange extension that provides adequate lip support. This study present a clinical case of an edentulous patient rehabilitated with an overdenture supported by dental implants and associated with the MK1 precision attachment system. Deficient upper lip support was diagnosed during clinical exam preventing treatment with an implant-fixed dental prosthesis. The use of the MK1 attachment system on the implant-supported overdentures allowed the adequate upper lip support that the patient needed, contributing to the final facial esthetics and the reestablishment of masticatory function. The attachment system also provided characteristics of an implant-fixed restoration, without palatal covering and also provided easy access for adequate oral hygiene procedures.