Altered reverse impression method involving extraoral digitalization of a verification jig for the fabrication of implant-supported prosthesis by using a complete-digital workflow.

The reverse impression method involves the extraoral digitalization of the interim implant-supported prostheses and intraoral digitalization of antagonist arch and maxillomandibular relationship. This technique allows the fabrication of implant-supported prostheses by using a complete-digital workflow. The scan analogs make the reverse impression method feasible. However, this method may not be recommended if the interim polymethyl methacrylate prosthesis does not have passive fit. The present manuscript describes an altered reverse impression technique that involves the extraoral digitalization of a conventional verification jig, which has attached scan analogs. With this technique modification, the implant positions captured using the verification jig are used to obtain the virtual definitive implant cast and fabricate the definitive implant-supported prosthesis.

A modified reverse impression technique for capturing and transferring soft-tissue information.

The reverse impression technique consists of the extraoral digitalization of an implant-supported interim prosthesis by placing scan analogs in an interim implant-supported prosthesis. The technique facilitates the recording of implant and tooth positions and allows the digitalization of the volumetric dimensions of the interim restoration. However, it is not able to register soft tissue changes during the healing process. A modified reverse impression technique is described to facilitate capturing the current dimensions and soft tissue information at the time of the definitive implant scan. Additionally, the modified technique includes the use of a verification device. The extraoral digitalization of the verification device minimizes complications caused by the lack of passive fit of the milled interim polymethyl methacrylate prosthesis.

Using an additively manufactured natural head position reference device to transfer the horizon orientation plane and integrate it with a 3-dimensional virtual patient: A dental technique.

A virtual patient is obtained by aligning a patient's digital information, including facial and intraoral digital scans with or without hard tissue information from a cone beam computed tomography scan. However, while computer-aided design programs facilitate virtual patient integration, they do not provide a way to relate the horizon orientation with the patient's horizontal and vertical facial references. The present technique describes a way of relating the horizon orientation plane to the natural head position of the patient. An additively manufactured natural head position reference device was used to transfer the horizon orientation plane to the 3-dimensional virtual patient.

Is the Fixed Mandibular 3-Implant Retained Prosthesis Safe and Predicable for Full-Arch Mandibular Prostheses? A Systematic Review.

PURPOSE: To evaluate implant and prosthetic survival rates of full-arch rehabilitations retained by three implants in patients with edentulous mandibles. MATERIALS AND METHODS: This systematic review was developed following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. The focused question was: Are fixed mandibular 3-implant retained prostheses safe and predicable for full-arch mandibular prostheses? The Medline/PubMed and Cochrane Library databases were used to conduct the systematic search for clinical trials on fixed mandibular 3-implant retained prostheses published between 1999 and 2020. Only English-language studies that presented information on implant and prosthetic survival were included. RESULTS: A total of 302 studies were identified, of which 13 addressed the inclusion criteria. Additionally, 574 participants were included in these studies. As reported, 73 (4.57%) of 1596 implants failed, with a survival rate of 95.43%. In addition, the mean survival rate of the presented prostheses was 89.66%. The mean marginal bone loss was 1.09 mm. CONCLUSION: Within the limitations of the present review, implant and prosthetic survival rates of fixed mandibular 3-implant retained prostheses were similar to those of full-arch mandibular prostheses retained by four or more implants. Further research exploring the topic is necessary.

Técnicas de afastamento gengival em prótese dental: revisão da literatura / Gingival retraction methods in dental prosthesis: literature review

A proposta desta revisão da literatura foi avaliar as técnicas empregadas no afastamento gengival para prótese dental incluindo métodos mecânicos, químicos-mecânicos e cirúrgicos. A técnica de afastamento gengival deve ser previamente avaliada pelo profissional e a sua indicação, dependerá de cada situação clínica. Nesta revisão foram apresentadas as vantagens e desvantagens das técnicas de afastamento gengival incluindo fio afastador embebido ou não em soluções químicas, técnicas cirúrgicas, procedimentos a base de laser, curetagem gengival e eletro cirurgia. Após a realização desta revisão verificamos que o método químico-mecânico é o mais utilizado pelos profissionais. Atualmente podemos considerar que mesmo com a utilização de tecnologias mais elaboradas, como por exemplo scanners intraorais, quando o término do preparo dental estiver ao nível gengival ou subgengival se faz necessário o afastamento gengival. Para atingir o sucesso de uma prótese dental e importante coexistir uma harmonia entre a prótese e os tecidos periodontais circunvizinhos. (AU)

The aim of this review was to assess the use of gingival retraction methods in the fixed tooth supported prosthesis including mechanical, chemicals-mechanical and surgical methods. The choice of the best gingival retraction technique should be considered previously by the professional and it depends of each individual clinical conditions. In this review were discussed the advantages and the disadvantages of each gingival retraction technique including mechanical, chemical and surgical methods. In this review, we could understand that chemicals-mechanical technical is the most indicate by dentists. Nowadays, we can consider that even with the hightech use in dental area, such as intraoral scanners, when the margin of the restoration is placed sub-gingivally the gingival retraction should be considered. For the successful in dental prosthesis, a healthy coexistence between the restoration and their surrounding periodontal structure should be the goal of a prosthodontist. (AU)

Extrusion shear strength between an alumina-based ceramic and three different cements.

STATEMENT OF PROBLEM: Surface treatment is an essential step in bonding a ceramic to resin. Alumina ceramics are particularly difficult to prepare for adequate bonding to composite resin cements. PURPOSE: The purpose of this study was to evaluate the bond strength between a densely sintered alumina ceramic and bovine dentin with 2 adhesive resin cements and a resin-modified glass ionomer cement using an extrusion shear strength test. MATERIAL AND METHODS: Alumina cones (n=30), 4 mm in height, 3 mm in diameter at the small end, and with an 8-degree taper, were fabricated. Without any treatment, the cones were cemented in a standardized cavity in 2.5-mm-thick bovine dentin discs using 1 of 3 cement systems: Panavia F, RelyX ARC, or RelyX Luting. The cements were manipulated following the manufacturers' instructions. After 24 hours of storage at 37 degrees C, an extrusion shear test was performed in a universal testing machine at 0.5 mm/min until bonding failure. The data were analyzed using 1-way ANOVA and Tukey HSD test (alpha=.05). All fractured specimens were examined at x25 magnification and classified by fracture mode. Representative specimens were selected for SEM observation. RESULTS: The highest strength values were obtained with Panavia F, and they were significantly higher (P<.05) than each of the other 2 cements, which were not significantly different from each other. Panavia F resulted in predominantly mixed failure and RelyX ARC and RelyX Vitremer showed primarily adhesive failure. CONCLUSIONS: An MDP-containing adhesive system (Panavia F) provides better extrusion bond strength to a high-density alumina ceramic than a Bis-GMA resin luting agent system (RelyX ARC) or a resin-modified glass ionomer cement system (RelyX Luting).

Faceta laminada Procera AllCeram: um novo conceito / Procera AllCeram laminate: a new concept

O autor relata um caso de emprego de facetas laminadas Procera AllCeram na restauraçäo de dentes anteriores superiores manchados e fraturados. Säo descritos e ilustrados os passos clínicos e laboratoriais da confecçäo das facetas, ressaltando-se vantagens tais como a simplicidade da técnica, a precisäo na adaptaçäo marginal e os ótimos resultados estéticos alcançados

Uso de resina fotopolimerizável em apoios para prótese parcial removível / Use of photopolymerizable resin on stay for removable partial denture

Sabe-se que por fatores estéticos e mecânicos, os apoios incisais nos dentes anteriores, em próteses parciais removíveis a grampo, deveriam ser substituídos pelos apoios sobre o cíngulo nos dentes superiores ou por apoios na região lingual nos dentes inferiores. Com o advento das resinas compostas e da técnica do ataque ácido, surgiu uma nova possibilidade de se modificar a anatomia dentária, pois este material permite a construção de cíngulos para se obter descansos a plano guia, assim como propicia a criação de superfícies retentivas. Portanto, foi proposta desta revisão apresentar este assunto de forma mais detalhada.

Prótese fixa anterior em "cant-lever" na clínica de odontopediatria / Prior fixed prothesis in cant-lever at pedodontics clinical

Este trabalho consiste na apresentaçäo de uma técnica alternativa para resolver os problemas de perda prematura de dentes decíduos anteriores. Com esta finalidade, foi utilizada a prótese com extremidade livre, com dois dentes pilares e um pôntico. O trabalho foi realizado em três pacientes, que estäo sendo controlados através de observaçäo clínica e radiográfica, sendo que outros casos estäo em sua fase final de elaboraçäo. Nossa experiência demonstrou ser esta técnica, bastante satisfatória quanto a estética, funçäo e aceitaçäo por parte do paciente