Strain Behavior of Implant-Supported Full-Arch Fixed Dental Prostheses Supported by Four or Five Implants.

PURPOSE: Strains transferred to the supporting simulated bone structure by implant-supported full-arch fixed dental prostheses (FAFDPs) were analyzed by digital image correlation (DIC). MATERIALS AND METHODS: Polyurethane models were made using 3.75 × 11-mm implants and divided into the following groups with different implant numbers and design: EH5 (five implants/external hexagon), MT5 (five implants/internal taper), EH4 (four implants/external hexagon), and MT4 (four implants/internal taper). Both qualitative and quantitative (one-way analysis of variance [ANOVA] statistical comparison) analyses were performed by the DIC method after the application of a 250-N load in the central fossa of the mandibular first molar. Different regions of interest were selected in the polyurethane model for comparison between groups. RESULTS: Compressive strains were found in the cervical region of the models, and tensile strains were found in the apical region of the models. Significant differences were found in the different analyzed regions of interest for the different number of supporting implants and implant designs (P < .05). CONCLUSION: Groups with five implants showed more regions with less strain concentration compared to groups with four implants, but strain distribution was similar between groups. The different tested implant designs showed similar strain concentration and distribution to the supporting structures.

A Zygomatic Bone Study Using Virtual Dental Implant Planning Software.

This study evaluated the anatomical factors that influence the virtual planning of zygomatic implants by using cone-beam computerized tomography (CBCT) scans. CBCT scans of 268 edentulous patients were transferred to specialized implant planning software for the following measurements: maxillo-sinus concavity size (small, medium, and large), zygoma width, implant insertion angle, implant length, and implant apical anchorage. Concavity sizes found were as follows: 34.95% small, 52.30% medium, and 7.35% large. The mean insertion angle was 43.2 degrees, and the average implant apical anchorage was 9.1 mm. The most frequent implant length was 40 mm. Significant differences were found when the different types of concavities in relation to the installation angle, the distance of the apical portion of the implant in contact with the zygomatic bone, and the lateral-lateral thickness of the zygomatic bone were compared (P < .001). Medium-sized maxillary sinus concavity presented greater apical anchorage of the implant (9.7 mm) and was the most frequent type (52.30%). The zygomatic bone is a viable site for zygomatic fixtures, and the use of specialized implant planning software is an important tool to achieve predictable outcomes for zygomatic implants and allows good visualization of the relation between implants and anatomical structures.

Atividades extensionistas de educação em saúde bucal para pacientes da terceira idade: relato de experiência / Extension activities in oral health education for elderly patients: an experience report

Trata-se de um estudo de caráter descritivo, do tipo relato de experiência,que tem por objetivo descrever as atividades extensionistas desenvolvidas pelo projeto "Promoção da Saúde Bucal para Pacientes da Terceira Idade" da Universidade Estadual de Londrina em Pastoral da Pessoa Idosa e Instituições de Longa Permanência para Idosos em Londrina/PR e região. Essas ações foram desempenhadas por estudantes, docentes e servidores nos anos de 2017, 2018 e 2019 por meio de palestras e rodas de conversas sobre alimentação saudável, doenças causadas por próteses e doenças bucais. Além disso, foram realizadas escovação dentária supervisionada individual e coletiva, higienização de próteses, exame físico e autoexame. Em relação aos resultados, observou-se que as atividades possibilitaram identificar a realidade vivenciada dessa população, compartilhar saberes e experiências sobre saúde bucal com informações claras e acessíveis para a comunidade. Adicionalmente, essa oportunidade viabilizou aos estudantes estabelecerem vínculos sociais efetivos, a tomada de decisão, a liderança, proatividade e protagonismo. Favoreceu a formação contextualizada e integrada dos estudantes, com atitudes condizentes para realizar atendimentos e cuidados com a pessoa idosa e seus cuidadores em cenários diversificados. Dessa forma, atividades extensionistas revelaram-se poderosas estratégias para estudantes fortalecerem a formação profissional por meio do trabalho de educação em saúde com idosos e cuidadores (AU).

This is a descriptive study of the experience report type with the purpose of describing the extension actions developed by the project "Promotion of Oral Health for Elderly Patients" developed by the State University of Londrina at the Pastoral of the Elderly and Long-Stay Institutions for the Elderly in the city of Londrina/PR and region. These actions were developed by students, professors, and civil servants in 2017, 2018, and 2019 through lectures and talk sessions on healthy eating habits, diseases caused by prosthetics, and oral diseases. Additionally, supervised individual and collective toothbrushing, cleaning of prosthetics, physical examination and self-examination were developed. In relation to the results, it was observed that the activities allowed the students to identify the reality of that population, sharing knowledges and experiences on oral health with clear and accessible information for the community. Furthermore, this opportunity allowed the students to establish effective social bonds, improve their decision-making process, leadership, proactivity, and protagonism. It also favored the contextualized and integral training of the students, with befitting attitudes to provide care for the elderly and their caregivers in diversified scenarios. Therefore, the extension activities were powerful strategies for the students to strengthen the professional training through health education work with the elderly and their caregivers (AU).

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.

Restauração estética implantossuportada de dente anterior utilizando pilar protético com interface de titânio e zircônia / Anterior tooth implantsupported esthetic restoration using a titanium-zirconia interface prosthetic abutment

Os componentes protéticos em restaurações implantossuportadas atuam como intermediários entre a prótese e o implante, evitando que a prótese seja parafusada diretamente sobre o implante. O titânio ainda é o material mais utilizado para fabricação destes componentes, mas pode levar à coloração acinzentada do tecido gengival, prejudicando o resultado final estético. Com isso, a zircônia tem sido cada vez mais utilizada, principalmente em restaurações anteriores. Este artigo relatou um caso clínico com a confecção de restauração implantossuportada de dente localizado em região anterior (incisivo central superior direito) utilizando um intermediário protético fabricado em zircônia associado a um componente metálico parafusado sobre o implante. A paciente compareceu à clínica odontológica com um implante dentário instalado na região do incisivo central superior direito (dente #11). Foi fabricado um componente em titânio (pilar interface) para ser parafusado diretamente sobre o implante, e que seria associado a um pilar customizado de zircônia, preso por fricção ao componente de titânio e com o auxílio de parafuso. Tanto o pilar customizado quanto a restauração final foram fabricados com tecnologia CAD/CAM (computer-aided design/computer-aided manufacturing). A restauração foi fabricada em dissilicato de lítio e cimentada adesivamente com cimento resinoso. A restauração implantossuportada de dente localizado em região anterior, com o uso de pilar híbrido fabricado em zircônia associado a componente metálico parafusado sobre o implante, apresentou resultados clínicos satisfatórios e estética otimizada, sendo uma opção bastante viável para a restauração de dentes anteriores. (AU)

The prosthetic components in implant-supported restorations are intermediary between the prosthesis and the implant, thus avoiding direct prosthetics screwing. Titanium remains the most used material but the its coronal gray area compromises esthetics. Zirconia has therefore been increasingly used to improve the final esthetic outcome. This article will describe the implantsupported restoration of an anterior tooth (right upper central incisor) by using a titanium-zirconia interface prosthetic abutment. The patient arrived at the dental office with an implant already placed at the right upper central incisor region. Both the titanium-zirconia interface prosthetic abutment and the final restoration were fabricated by using CAD/CAM (computer-aided design/computer-aided manufacturing) technology. The final restoration was fabricated in lithium disilicate and luted using resin cement. The implant-supported restoration of an anterior tooth using a titanium-zirconia interface prosthetic abutment screwed to the implant showed a satisfactory clinical outcome and optimized esthetics, thus being a reliable option to restore anterior teeth. (AU)

Influence of cortical bone anchorage on the primary stability of dental implants.

PURPOSE: This retrospective chart review study assessed patient records to determine implant insertion torque (IT) and implant stability quotient (ISQ) values during implant placement to evaluate the correlation with cortical bone anchorage (mono- or bicortical). METHODS: Primary stability data (IT during implant placement surgery and ISQ values immediately after implant placement) and cone beam computed tomography of 33 patients (165 implants) were assessed. Patients were divided into the following groups: G1, implants with apical cortical bone contact; G2, implants with bicortical bone contact (apical and cervical regions); and G3, implants with cervical cortical bone contact. RESULTS: Sixty-eight implants were excluded due to cortical bone contact on regions other than implant apical or cervical. Ninety-seven implants were therefore assessed for this study. No implant failure was found after a mean 70.42-month follow-up time. Implants with bicortical anchorage (G2) showed higher IT (64.1 Ncm) during implant placement and higher ISQ values (76) (p < 0.05). Monocortical implants (G1, apical, and G3, cervical) showed similar IT (G1 52.3 and G3 54.3) and ISQ values (G1 71.9 and G3 73) (p > 0.05). No correlation (Pearson correlation coefficient) was found between the two stability measurement devices for the different cortical bone anchorages that were analyzed (G1 0.190, G2 0.039, and G3 - 0.027) (p > 0.05). CONCLUSIONS: Insertion torque values and implant stability quotients were influenced by cortical bone contact. No significant correlation was found between IT and ISQ values-higher insertion torque values do not necessarily lead to higher implant stability quotients.

Influence of Different Screw Torque Levels on the Biomechanical Behavior of Tapered Prosthetic Abutments.

PURPOSE: To study the force used for tightening tapered one-piece prosthetic abutments and their influence on the removal torque value and stress level of the prosthetic abutment after cyclic loading. MATERIALS AND METHODS: Fourteen implants and prosthetic abutments were divided into two groups (n = 7): G1, 20 Ncm; and G2, 32 Ncm (manufacturer recommended). A 20-mm T-shaped horizontal bar was adapted to the abutments. A 12-Hz cyclic loading was applied to the specimens in an electrodynamic testing system with the maximum number of cycles set to 106. Specimens were inclined by 15 degrees from the vertical axis, and a 5-mm off-center vertical load was applied to generate a combination of bending and torquing moments on the tapered connections. Progressive loads (from 164.85 to 362.85 N) were applied when the previous sample survived 106 cycles. The paired t test compared the screw removal torque with the initial tightening torque for each group (α = .05). A finite element analysis (FEA) of the mechanical testing analyzed the regions of stress concentration. RESULTS: No specimens failed after 106 cyclic loadings. The mean screw removal torque for both groups was similar to the initial abutment torque value applied for each group (G1, 20.36 ± 8.73 Ncm; and G2, 35.61 ± 6.99 Ncm) (P > .05). FEA showed similar stress behavior for both groups in the study despite the different simulated screw preloads (G1: 200 N; G2: 320 N). The coronal region of the implant body presented the highest strain values in both groups. CONCLUSION: Tightening tapered one-piece prosthetic abutments at 20 and 32 Ncm maintains a stable connection after cyclic loading. The stresses generated by the different tightening forces during cyclic loading are highest at the coronal level of the connection.

Seleção de componentes protéticos no sistema de conexão cone morse ­ relato de casos / Prosthetic components selection in cone morse connections system ­ case reports

Estão disponíveis no mercado diversos sistemas de implantes, que oferecem diferentes conexões entre restaurações protéticas e implantes. A seleção desses componentes e do sistema de conexão devem ser levadas em consideração como parâmetro de sucesso do tratamento com implantes osseointegrados. Os pilares para implante devem satisfazer requisitos biológicos, funcionais e estéticos. Biologicamente, devem promover adesão epitelial e não provocar fixação de biofilme, sendo de material biocompatível. Funcionalmente, devem transmitir de maneira eficiente as forças ao implante e o osso de suporte. E por fim, esteticamente, devem possuir contornos anatômicos adequados e correta inclinação para um posicionamento ideal do dente. Dessa maneira, o presente trabalho tem como objetivo a apresentação de casos clínicos, onde foram selecionados componentes protéticos em reabilitações utilizando implantes cone Morse.

Many implant systems are available in the market which offer different connections between prosthetic abutments and implants. The selection of these components and of the implant connection should be taken into account as a parameter of treatment success with osseointegrated implants. The implant abutments must meet biological, functional and aesthetic requirements. Biologically, they should promote epithelial adherence and not cause biofilm adhesion, also being fabricated with biocompatible material. Functionally, they must efficiently transmit forces to the implant and supporting bone. Finally, aesthetically, they must have adequate anatomical contours and the correct inclination for an ideal tooth positioning. This study aims to present clinical cases, in which prosthetic components were selected for rehabilitations using Cone Morse implants.

Strain transfer behavior of different planning options for mandibular single-molar replacement.

STATEMENT OF PROBLEM: The loss of the first molar and second premolar could lead to mesial movement of the second molar, thus limiting the restoration space for the 2 missing teeth. Placement of a larger first molar is a common choice, but the best implant number and position option remain controversial. PURPOSE: The purpose of this in vitro study was to test different planning options for replacing the mandibular first molar. MATERIAL AND METHODS: Two polyoxymethylene models simulated first molar edentulous spaces of 11 mm (conventional size first molar: control group) and 14 mm (enlarged first molar: all remaining groups other than control). Models included acrylic resin replicas of a first and second premolar, a second molar, and the first molar edentulous space. The following groups were established: control (CO), ø3.5-mm center implant; center implant (CI), ø3.5 mm; mesial implant (MI), ø3.5 mm; distal implant (DI), ø3.5 mm; center implant (WI), ø5.0; 2 implants (2I), 2 ø3.5-mm implants. Three Co-Cr molar crowns were fabricated for each group by using a computer-aided design and computer-aided manufacturing (CAD-CAM) technique. Model surface strains under a 250-N first molar load were calculated by 3-dimensional digital image correlation. Three regions of interest below the first molar were selected for comparison among groups. A test for unequal variances and a follow-up Welch ANOVA were used for statistical analysis (α=.05). RESULTS: The highest strains were found when the first molar was restored by using a 5.0-mm-wide implant (P<.05). Region of interest 1 showed that two 3.5-mm implants replacing the lost molar showed strain distribution similar to that of only one 3.5-mm implant (P>.05). Mesial and distal placement of the implant showed more neutral strain results than other restoration options (P<.05). CONCLUSIONS: Two small-diameter implants in an increased edentulous space show more optimized surface strain behavior than a single wide-diameter implant. However, a single 3.5-mm implant also showed reduced strains in the restoration of the same edentulous space.

Mandibular angle fractures treated with a single miniplate without postoperative maxillomandibular fixation: A retrospective evaluation of 50 patients.

OBJECTIVE: This retrospective study evaluated the use of a single miniplate for the treatment of mandibular angle fractures (MAF). METHODS: Fifty patients with 53 MAF were treated by open reduction and internal fixation with the use of a single miniplate and were analyzed in this study. RESULTS: Five patients with MAF had postoperative complications that required additional procedures. Three patients had postoperative infection, one patient complained of malocclusion in the first postoperative week, and one patient had miniplate exposure three months after surgery. Every additional procedure was performed in the office under local anesthesia without disruption of the initial fracture treatment. Postoperative maxillomandibular fixation (MMF) was performed in four patients. Treatment of MAF using a single miniplate was effective, with low morbidity and with low rates of postoperative complications. MAF can be treated without MMF, and stability is improved when long miniplates are used. CONCLUSIONS: The use of a single miniplate is therefore encouraged. However, postoperative MMF should be considered with the presence of little contact between bone segments, malocclusion, or extensive tooth loss.

Biomechanical behavior of titanium and zirconia frameworks for implant-supported full-arch fixed dental prosthesis.

BACKGROUND: The biomechanical behavior of implant-supported titanium and zirconia full-arch fixed dental prosthesis (FAFDP) frameworks require further investigation. PURPOSE: Strains transferred by implant-supported titanium (Ti) and zirconia (Zr) FAFDP frameworks were analyzed. MATERIALS AND METHODS: Maxillary 14-unit FAFDPs supported by 6 implants and 12-unit FAFDPs supported by 4 implants were tested. One-piece frameworks were fabricated by computer-aided design/computer-aided manufacturing. Four groups were divided (n = 3): G1, Ti-6 implants; G2, Zr-6 implants; G3, Ti-4 implants; G4, Zr-4 implants. A 250 N single-point load was applied on the second premolar. A three-dimensional digital image correlation system recorded framework and maxilla model surface deformation. RESULTS: The following strains (µS) averaged over the length of the second premolar were calculated: frameworks, G1 (321.82 ± 111.29), G2 (638.87 ± 108.64), G3 (377.77 ± 28.64), G4 (434.18 ± 132.21); model surface, G1 (473.99 ± 48.69), G2 (653.93 ± 45.26), G3 (1082.50 ± 71.14), G4 (1218.26 ± 230.37). Zirconia frameworks supported by 6 implants (G2) presented higher surface strains (P < .05). FAFDPs with titanium frameworks transferred significantly lower strains to the supporting maxilla when 6 implants were used (G1) (P < .05). Both framework materials transferred similar strains when supported by 4 implants (G3 and G4) (P > .05). CONCLUSIONS: Zirconia frameworks supported by 6 implants showed higher strains. FAFDPs supported by 6 implants transferred less strains to the supporting maxilla, irrespective of framework material.

Fluxo de trabalho digital para a reabilitação estética dos dentes anteriores / Digital workflow for the esthetic restoration of anterior teeth

Os métodos digitais atualmente disponíveis para o planejamento e fabricação das restaurações permitem padronização e melhor previsibilidade para os resultados funcionais e estéticos finais. A qualidade atual dos equipamentos digitais disponíveis melhorou a qualidade dos processos de confecção e possibilita que o número de sessões clínicas seja reduzido. Este artigo irá descrever a restauração dos 6 dentes superiores anteriores de paciente insatisfeita com o aspecto estético inicial do seu sorriso. O planejamento e confecção das restaurações propostas foram realizados com auxílio dos métodos digitais disponíveis atualmente. Os dentes foram todos restaurados com coroas totais fabricadas em dissilicato de lítio. Pôde-se concluir que o domínio do fluxo de trabalho digital permite maior padronização no planejamento e fabricação das restaurações estéticas, possibilitando resultados previsíveis e maior sucesso clínico. A melhor comunicação com o paciente e a menor quantidade de sessões clínicas necessárias para o tratamento completo do paciente são grandes vantagens do tratamento digital. Já o custo elevado dos equipamentos ainda é uma desvantagem, mas seu progressivo barateamento irá permitir cada vez mais seu uso na clínica diária.

The methods currently available for digital planning and manufacturing of restorations allow more standardized and predictable functional and esthetic outcomes. The current state of the art of digital equipment improved the manufacturing procedures and allowed the reduction of clinical sessions needed for complete patient treatment. This article will describe the restoration of 6 anterior maxillary teeth of a patient unsatisfied with her smile esthetics. The planning and manufacturing of restorations were all conducted by using the currently available digital methods. All teeth were restored with lithium disilicate crowns. It could be concluded that the digital workflow allows more standardization in planning and manufacturing restorations, allowing more predictable results and highly successful outcomes. The best communication with the patient and the reduced number of clinical sessions are great advantages of the digital treatment. however the high costs of equipment is still a disadvantage, but a possible future cost reduction will allow its increased use in daily clinical practice.

A Digital Image Correlation Analysis of Strain Generated by 3-Unit Implant-Supported Fixed Dental Prosthesis: An In Vitro Study.

OBJECTIVE: To evaluate the influence of different veneering materials (porcelain and resin) and implants (short and conventional) in the strain distribution of implant-supported splinted fixed partial dentures (FPDs) using digital image correlation (DIC). MATERIAL AND METHODS: Four polyurethane models were fabricated with resin replicas (first premolar) and short and/or conventional implants replacing the second premolar and first and second molars, according to the following configurations: G1, 2 conventional (second premolar and first molar) and 1 short (second molar) implant; G2, 1 conventional (second premolar) and 2 short (first and second molar) implants; G3, 3 short implants; G4, 3 conventional implants. Porcelain- and resin-veneered splinted FPDs were screwed to the implant abutments. The DIC system was used to calculate strains during application of occlusal load (250 N). RESULTS: Porcelain- and resin-veneered showed similar strain distribution for all groups (P > 0.05). Concentration of compressive strains was higher in G3P and G3R with maximum compressive strains of -1271.50 and -1026.88 µs, respectively. G4 transferred the best strain distribution (porcelain, -275.14 µs; resin, -254.44 µs), followed by G2 (porcelain, -306.79 µs; resin, -310.63 µs). CONCLUSION: The veneering material used did not influence the strain distribution. In addition, conventional implants generate less strain concentration, although the combination of 2 short and 1 conventional implant seems to be a viable plan.

Fracture Strength of Standard and Small Diameter Prosthetic Abutments for Full-Arch Implant-Supported Restorations.

This study tested the fracture strength of prosthetic abutments with different sizes and combinations to support a 5-implant milled framework with distal extension. Prosthetic abutments with different dimensions (4.8-mm diameter mini conical abutment and 3.5-mm diameter microconical abutment) were screwed to 5 threaded implants. The following groups were divided (n = 3): G1 with 5 miniconical abutments (standard size), G2 with 5 microconical abutments (small sized), G3 with a combination of 3 small sized abutments and 2 standard sized abutments, and G4 with a combination of 2 small sized abutments and 3 standard sized abutments. Standardized titanium frameworks for full-arch fixed dental prosthesis were milled with equidistant holes for each of the 5 implants and abutments. A loading point was selected at 18 mm away from both distal implants. A universal testing system was used for the fracture strength tests and load was applied at a crosshead speed of 0.5 mm/min on the previously described loading points until component fracture. Mean fracture strength for each group was statistically compared (α = 0.05). Prosthetic screws were the only fractured components for all tested groups. Mean fracture strength was: G1, 1130.22 N; G2, 1031.36 N; G3, 757.9 N; and G4 792.03 N (P < .05). All prosthetic abutments and combinations that were tested provide adequate fracture strength for clinical use. However, the combination of standard and small diameter abutments leads to lower fracture strength compared with when only standard sized prosthetic abutments were used, irrespective of the abutment diameter (4.8- or 3.5-mm).

Zircônia translúcida associada ao planejamento digital de restaurações monolíticas implantossuportadas / Translucent zirconia associated with the virtual design of monolithic implant-supported restorations

A utilização dos sistemas digitais aumentou consideravelmente na Odontologia e está cada dia mais acessível. Relatos de sucesso com o uso de restaurações cerâmicas livres de metal também são mais constantes. Os sistemas digitais trazem novas possibilidades de planejamento e fabricação para as restaurações cerâmicas, além de aumentar a previsibilidade dos tratamentos devido à visualização virtual da restauração que será fabricada. Atualmente, a zircônia translúcida associada à caracterização extrínseca, na forma de coroas monolíticas, permite resultados altamente estéticos e apresenta resistência adequada para a aplicação segura em dentes posteriores. O presente artigo teve como objetivo apresentar um caso clínico no qual o primeiro molar inferior direito foi restaurado com uma coroa monolítica em zircônia translúcida, obtida por tecnologia CAD/CAM e maquiada por caracterização extrínseca.

The application of digital dentistry has grown and seems more avalilable in dentistry. Reports of clinical success are constant. Digital dentistry allows clinicians to design and fabricate predictable restorations for daily clinics. The virtual design of the restoration is also an excellent tool to predict the final outcome of the rehabilitation by the patient, thus leading to more predictable and esthetically successful outcomes. Monolithic translucent zirconia associated with external staining allows highly esthetic results and with adequate fracture strength for the use in posterior teeth. This study will describe the restoration of a mandible first molar with the aid of digital impression, and virtual planning and CAD/CAM fabrication of the restoration. The restoration was fabricated by using monolithic translucent zirconia and characterized with external staining.

Influence of Cyclic Fatigue in Water on Screw Torque Loss of Long-Span One-Piece Implant-Supported Zirconia Frameworks.

PURPOSE: It is still unclear whether four, six, or more implants should be used when restoring fully edentulous maxillae. This research evaluated the in vitro screw torque loss of zirconia frameworks supported by six implants and cantilevered zirconia frameworks supported by four implants. MATERIALS AND METHODS: Computer aided design/computer-assisted machining was used to fabricate 10 one-piece frameworks. Standardized pressable porcelain crowns were fabricated and luted to the frameworks. Specimens were divided into two groups (n = 5): AO4, cantilevered 12-unit full-arch fixed dental prosthesis supported by four implants; AO6, 14-unit supported by six implants. An opposing mandibular dental arch was fabricated with bis-acrylic composite resin. Specimens were submitted to 200 N underwater cyclic load at 2-Hz frequency for 1 × 106 cycles in a controlled 37°C temperature. A digital torque gauge assessed the initial and postload screw removal torque. Linear mixed-effects model was used for statistical analysis (α = 0.05). RESULTS: Significant screw torque loss was found for AO6 after cyclic loading (before: 36.20%/after: 52.82%; p < 0.05). Group AO6 (36.20%) presented lower preload loss before the cyclic loadings compared with AO4 (60.10%) (p < 0.05). CONCLUSIONS: Cyclic loading and lower implant-to-replaced-units ratio do not seem to compromise screw stability compared with higher implant-to-replaced-units ratio; however, a steep drop in preload was found before cyclic loading for both groups.

Effect of different implant placement depths on crestal bone levels and soft tissue behavior: a randomized clinical trial.

OBJECTIVES: This randomized clinical trial analyzed crestal bone changes and soft tissue dimensions surrounding implants with an internal tapered connection placed in the mandible anterior region at different depths (equicrestal and subcrestal). MATERIALS AND METHODS: Eleven edentulous patients (five implants per patient) were randomly divided in a split-mouth design: G1, 28 equicrestal implants; and G2, 27 subcrestal implants. All implants were immediately loaded. Correlation between keratinized tissue width (KTW) and vertical mucosa thickness (MT) with soft tissue recession was analyzed. Intraoral radiographs were used to evaluate crestal bone changes. Patients were assessed immediately, 4-, and 8-months after implant placement. Rank-based ANOVA-type statistical test was used for comparison between groups (α = 0.05). RESULTS: Fifty-five implants (G1 = 28 and G2 = 27) were assessed in 11 patients. Implant survival rate was 100% for both groups. Both tested implant placement depths presented similar crestal bone loss (P > 0.05). Significant crestal bone loss for each group was found in the different measurement times (T4 and T8) (P < 0.05). Implant placement depths, KTW, and vertical MT had no effect on soft tissue recession (P > 0.05). CONCLUSIONS: Different implant placement depths do not influence crestal bone changes. Soft tissue behavior is not influenced by different implant placement depths or by the amount of keratinized tissue.

Reabilitação estética dos elementos anteriores utilizando o sistema IPS e-max / Aesthetic rehabilitation of previous elements using the system IPS e-max

Este trabalho tem como objetivo relatar o caso clínico de paciente com a estética do sorriso comprometida. Neste caso foram realizadas facetas cerâmicas confeccionadas pelo sistema e-max CAD e coroa total cerâmica com “coping” de zirconia e cobertura com cerâmica pela técnica da estratificação. Foi realizado o enceramento diagnóstico sobre o modelo de estudo e o Mock-up, possibilitando à paciente a simulação do resultado final sem desgastes dentais realizados. Na sessão seguinte foi feita a escolha da cor das peças seguida da confecção dos preparos para facetas do elemento 13 ao 23, exceto no elemento 21, no qual foi realizado preparo periférico total para confecção de prótese fixa unitária. A moldagem foi feita na mesma sessão utilizando silicone de adição associada à técnica de afastamento gengival do duplo fio. Na última sessão foi efetuada a prova e cimentação das peças com o cimento Relyx Veneer. Por meio deste caso clínico foi possível concluir que o sistema IPS e-max possibilitou peças cerâmicas que supriram as necessidades estéticas da paciente

This work has as objective to report a clinical case of a patient with the aesthetic of her smile compromised. In this case were realized ceramic facets made by the Emax CAD system and all ceramic crown with Zirconia copping and cover with ceramic by layering technique. First, the diagnostic wax-up on the study model and the mock-up was performed, giving the patient a simulation of the result without performing dental wear-off. During the next session, color choice of the ceramic pieces was made, followed by the confection of preparatione for facets in the elements 13 to 23, except on the element 21, where a total peripheral preparation for making unit fixed prosthesis was made. The casting was prepared in the same session, using addition silicon associated with gingival retraction technique of double wire. In the last session, the proof and the cementation of pieces with the cement Relyx Veneer were accomplished. Considering this clinical case was concluded that the system IPS e-max allowed ceramic pieces that supply the aesthetic necessities of the pacient

Reabilitação protética de paciente maxilectomizados: relato de caso / Prosthetic rehabilitation of patients maxilectomizados: case report

O Ameloblastoma é uma neoplasia composta por epitélio odontogênico, sendo tumor de crescimento lento, localmente invasivo, e com grande capacidade de destruição e expansão, clinicamente persistente. O tratamento de escolha, na maioria dos casos, é a intervenção cirúrgica radical, que consiste na ressecção em bloco. A reabilitação protética é uma das alternativas de tratamento para solucionar defeitos faciais congênitos ou adquiridos. Este artigo irá relatar a reabilitação de paciente com prótese obturadora após ter passado por cirurgia de maxilectomia com sequelas de comunicação buco antral. A prótese obturadora foi confeccionada de forma que formaram-se bolsas pneumáticas para alívio do peso da mesma. A paciente compareceu à Clínica Odontológica Universitária de Universidade Estadual de Londrina (COU-UEL) usando prótese obturadora desadaptada e que causava desconforto. Após analise da prótese, planejou-se a reabilitação protética com prótese obturadora superior, e prótese parcial removível inferior, para melhor adequação do sistema estomatognático. Utilizou-se a técnica de dupla moldagem do arco superior e inferior com silicone de adição de consistência pesada. Foram confeccionadas zonas de alívio nos moldes obtidos da primeira moldagem e em seguida foram realizadas as moldagens com silicone de adição de consistência leve. Foi registrada a relação intermaxilar que possibilitou a adequada montagem dos dentes que, após prova e ajustes adequados, foi acrilizada. A prótese obturadora proporcionou melhor qualidade de vida devido a melhora na fonação, deglutição, estética, melhorando sua autoestima e reintegrando o indivíduo à sociedade

Ameloblastoma is a slow growing tumor of odontogenic epithelium, locally invasive, and with great capacity for tissue destruction and is clinically persistent. The treatment of choice in most cases is the radical surgical intervention, which constitutes of bloc resection. The prosthetic rehabilitation is an alternative treatment to solve congenital facial defects or acquired. Another treatment option is the reconstructive plastic surgery, but it depends on patient’s age, medical history, financial condition and defect extension. This clinical case will report the patient rehabilitation with obturator prosthesis after maxillectomy surgery with antral buco communication. The patient attended the COU / UEL using an obturator prosthesis. The prosthesis was poorly fitting and causing discomfort. After prosthesis analysis, prosthetic rehabilitation was planned with a maxillary obturator prosthesis and mandible removable partial dentures. Double impression technique was performed for both arches with heavy consistency addition silicone. Relief areas were prepared in the first impression and then another impression was performed with mild consistency silicone addition. The molds were cast in plaster type IV, for dies and production of evidence bases in clear acrylic resin with wax rollers for intermaxillary records. Intermaxillary relationship was recorded and allowed adequate teeth positioning. The obturator prosthesis provided a better quality of life due to improvement in speech, swallowing, aesthetics, and patient self-esteem

Substituição de próteses totais bimaxilares convencionais por prótese total superior e sobredentadura mandibular implantorretida com encaixes o´ring e barra-clipe: relato de caso / Replacing conventional bimaxillary total prostheses for superior total prosthese and mandibular overdenture implant-retained with o-ring and bar-clip fittings: case report

O presente trabalho tem por objetivo apresentar o caso clínico de uma paciente portadora de próteses totais bimaxilares há mais de 10 anos, queixando-se da estabilidade e da aparência estética das mesmas. Para planejar o tratamento, foram consideradas as características bucais apresentadas, tais como reabsorção alveolar severa em região posterior de mandíbula, além da condição financeira da paciente. Optou-se pela substituição das próteses totais convencionais bimaxilares por uma nova prótese total em maxila e uma sobredentadura mandibular. Implantes osseointegrados na região dos elementos dentais 33 e 43, ligados a uma infraestrutura fundida para sistemas de encaixe do tipo O´ring e barra-clipe, sustentaram a sobredentadura. A instalação dos implantes foi feita em dois estágios, como originalmente preconiza o sistema Branemark. Durante a fase de osseointegração dos implantes definitivos e confecção da sobredentadura final foram utilizados implantes transicionais, que sustentaram uma sobredentadura provisória. Este detalhe clínico possibilitou conforto a paciente durante o período de osseointegração, além de proporcionar maior previsibilidade em relação ao prognóstico do caso. Por fim, o tratamento realizado devolveu à paciente retenção e estabilidade as suas próteses, além das qualidades estéticas das mesmas, suprindo as queixas iniciais apresentadas pela paciente

This study aims to present a clinical case of a patient who had been using bi-maxillary dentures for over 10 years, and who complained about the stability and the aesthetic appearance of that. To plan treatment, it was considered the oral characteristics presented, such as severe alveolar resorption in the posterior mandible, beyond the financial condition of the patient. It was decided to do the replacement of the conventional bi-maxillary dentures for a new maxillary denture and a mandibular overdenture. Dental implants in the area of dental elements 33 and 43, connected a fused infrastructure for docking systems of the O’ring type and bar-clip, that sustained the overdenture. The implant placement was done in two stages, as originally recommended by the Branemark system. During the osseointegration phase of the definitive implants and preparation of the final overdenture, were used transitional implants, which supported a provisional overdenture. This clinical detail gave comfort to the patient during the period of osseointegration, in addition to providing more predictability in relation to the prognosis of the case. Finally, the treatment brought retention and stability of the prosthesis back to the patient. It also provided aesthetic qualities, eliminating the initial complaints of the patient