Previsibilidade de reabilitações de maxilas edêntulas com a técnica all-on-four: revisão de literatura / Previsibility of edental jaw rehabilitations with the all-on-four technique: literature review

Objetivo: avaliar a previsibilidade das reabilitações de maxilas edêntulas através da técnica all-on-four, mensurada pelas tensões sobre implantes em estudos laboratoriais e sobrevida de próteses, perda óssea marginal e sucesso dos implantes em estudos clínicos. Revisão de literatura: foi executada uma busca na literatura nas bases de dados Lilacs, SciELO e PubMed/Medline, utilizando termos relacionados ao tema, sem restrição temporal e adaptados para cada base. As buscas foram realizadas por um único examinador no período de setembro a novembro de 2019. Após a leitura crítica dos 21 artigos selecionados, constata-se que existem vários estudos com muitos delineamentos que avaliaram a previsibilidade mensurada de várias formas. Considerações finais: diante das evidências científicas encontradas, a reabilitação de maxilas edêntulas com a técnica all-on-four demonstra ser previsível e estável. Estudos retrospectivos, prospectivos e revisões sistemáticas relatam altos índices de sucesso, baixa perda óssea marginal, embasando o uso da técnica all-on-four na odontologia.(AU)

Objective: to assess the predictability of edentulous maxillary rehabilitation using the all-on-four technique, measured by tensions over implants in laboratory studies and prosthetic survival, marginal bone loss and implant success in clinical studies. Literature Review: A literature search was performed in the Lilacs, SciELO and PubMed/ Medline databases, using terms related to the theme, without time restriction and adapted for each base. The searches were carried out by a single examiner from September to November 2019. After a critical reading of the 21 selected articles, it appears that there are several studies with many designs that evaluated the predictability measured in various ways. Final considerations: In view of the scientific evidence found, the rehabilitation of edentulous jaws with the all-on-four technique proves to be predictable and stable. Retrospective, prospective studies and systematic reviews report high success rates, low marginal bone loss, basing the use of the all-on-four technique in dentistry.(AU)

Flapless implant placement with digital 3D imaging and planning system in fully edentulous patient: A case report and 5-year follow-up / 대한치과보철학회지

One of the fastest growing segments of implant dentistry is the utilization of computed tomography (CT) scan data and treatment planning software in conjunction with guided surgery for implant reconstruction cases. Computer assisted planning systems and associated surgical templates have established a predictable, esthetic, functional technique for placing and restoring implants. Especially, a philosophy of restoratively driven implant placement has been generally adopted. Recently, a variety of commercial dental fields have released their scanning and fabricating protocols and methods for restorations. This process is still being investigated and developed for the most precise and predictable outcome. This case report describes a female patient who wanted dental implants in fully edentulous areas. Restoratively driven implant placements were performed with surgical guide and the patient was fully satisfied with the clinical results, and at 5-year post restorative follow-up assessment, both implant and prosthesis were proved clinical success.

Application of All-on-Four technology in the field of dental implants / 口腔疾病防治

@#Dental implant restoration is an effective way to restore the chewing and aesthetic function for edentulous. However, dental implant restoration is facing great challenges of the lack of available bone, the maxillary sinus or inferior alveolar nerve vascular bundle, which is often necessary to carry out the related bone augmentation operation. All-on-Four technique is to use four implants in the anterior part of complete edentulous jaws, the two most anterior implants are placed axially whereas the two posterior implants are placed distally angled, to support a provisional, fixed, and immediately loaded prosthesis. The technique avoids the artificial bone substitutes implantation and maxillary sinus augmentation or other bone augmentation surgery. Besides, it could alleviate patients' psychological reaction, postoperative reaction, as well as time and money costs. It is considered a feasible treatment method to combine the application of the oblique implant and the axial implant in the treatment of the edentulous patients. This paper will elaborate on the concept of All-on-Four, the conventional technology, the evaluation research and some new viewpoints.

Clinical application and research progress of All-on-Four / 口腔疾病防治

@#To seek convenient and effective method for reconstruction of edentulous jaw, Maló and his colleagues developed All-on-Four implant immediate-function concept. The principle of All-on-Four is to support the full-arch prosthesis by 4 implants and to achieve immediate loading after surgery. Its advantages include avoiding additional bone grafting, evading critical anatomical structures and immediate prosthesis. In recent years, All-on-Four technique has been widely utilized in clinical practice as a viable approach for edentulous patients. With the auxiliary of guided surgery and biomechanical researches, All-on-Four has achieved predictable clinical results. In this paper, the development, investigation of biomechanics and main points of surgery and prosthesis of All-on-Four were briefly reviewed.

Rehabilitación oral maxilar y mandibular con prótesis híbridas, utilizando implantes convencionales de una y dos fases e implantes zigomáticos en paciente con displasia ectodérmica. Caso clínico

La rehabilitación oral de un paciente edéntulo, especialmente con reabsorción severa, no deja de ser un reto para el clínico. En múltiples casos se requiere de procedimientos adicionales como injertos óseos con el objetivo de obtener volumen óseo y, finalmente, poder colocar los implantes dentales. En este artículo se aborda un caso de un paciente con displasia ectodérmica, el cual tiene algunas piezas dentales incluidas y reabsorción ósea severa. Se practicó exodoncias múltiples y la colocación de implantes dentales y zigomáticos, esto con el fin de eliminar los injertos óseos y poder realizar una rehabilitación bimaxilar de menor morbilidad, costo y tiempo.

The edentulous patient and his oral rehabilitation, specially with severe bone reabsorption is really a challenge for the clinician. In many situations the clinician requires additional procedures such as bone grafting in order to gain bone volume and finally be able to place the dental implants. In this article, we describe a patient with ectodermic dysplasia, who has some impacted teeth and severe bone reabsorption. In this case multiple dental extractions were performed and the placement of zygomatic implants with propose to avoid any bone grafting and be able to rehabilitated the patient at much less morbility, less cost and time.

Does matching relation exist between the length and the tilting angle of terminal implants in the all-on-four protocol? stress distributions by 3D finite element analysis

PURPOSE: To explore whether there is matching relation between the length and the tilting angle of terminal implants in the All-on-Four protocol by studying the effects of different implant configurations on stress distributions of implant, bone, and framework. MATERIALS AND METHODS: Four implants were employed to support a full-arch fixed prosthesis and five three-dimensional finite element models were established with CT images, based on the length (S and L) and distal tilt angle (0degrees, 30degrees and 45degrees) of terminal implants for an edentulous mandible, which named: Tilt0-S, Tilt30-S, Tilt30-L, Tilt45-S and Tilt45-L. An oblique 240 N was loaded at second molar. The von Mises Stresses were analyzed. The implants were consecutively named #1 to #4 from the loading point. RESULTS: 1) Tilt0-S had the greatest stress on the implants, with the other groups exhibiting variable reductions; the four implants of Tilt45-L demonstrated the greatest reduction in stress. 2) Tilt0-S had the greatest stress at bone around #1 implant neck, and Tilt45-L exhibited the least stress, which was a 36.3% reduction compared to Tilt0-S. 3) The greatest stress in the framework was found on the cantilevers distal to #1 implant. Tilt45-S exhibited the least stress. CONCLUSION: Matching different length and tilting angle of the terminal implants led to variable stress reductions on implants, bone and the superstructure. By optimizing implant configuration, the reduction of stress on implants and surrounding bone could be maximized. Under the present condition, Tilt45-L was the preferred configuration. Further clinical testings are required.

Rehabilitación de una maxila atrófica con el uso de implantes inclinados <

La reabsorción de la maxila presenta limitaciones en la colocación de implantes por medio de la técnica convencional. El concepto de <

Maxillary resorption inflicts limitations to implant placement when using conventional techniques. The concept of <

Reabilitação de maxila e mandíbula pela técnica all-on-four: acompanhamento clínico e radiográfico de três anos / Three-year clinical and radiological follow-up results using the All-on-Four concept in the completely edentulous patient: case report

Pacientes totalmente edêntulos, porém, com o inconveniente da limitada quantidade óssea e/ou pela pneumatização dos seios maxilares, têm resoluções desfavoráveis em abordagens como enxertos ósseos, implantes curtos, fixações zigomáticas. Uma alternativa conservadora é o all-on-four, consistindo na reabilitação de um paciente edêntulo com prótese fixa sobre quatro implantes, sendo dois posteriores inclinados e dois anteriores instalados verticalmente. Neste trabalho é apresentado um caso clínico de reabilitação total superior e inferior com carga imediata pela técnica all-on-four, destacando a utilização de implantes cone-morse na maxila e hexágonos externos na mandíbula e seus acompanhamentos durante três anos

Completely edentulous patients with limited bone quantity and/or maxillary sinus pneumatization can have unfavorable prognosis for therapies such as bone grafts, short implants, or zygoma fixtures. A conservative approach is the All-on-Four technique, where a fixed prosthesis is delivered over four implants, being the posterior elements inclined and the anterior fixtures in a vertical position. In this report we describe a case of immediate loading along with this technique, using cone morse connetion implants in the upper arch and external hexagon types in the lower arch. This case have been examined for three years

Estudo do comportamento biomecânico em protocolos modificados de brånemark(conceito ALL-ON-FOUR): análise por extensometria linear elétrica / Study of Biomechanical behavior in modifyed Brånemark protocols: Strain Gauge analysis

O objetivo deste estudo foi analisar in vitro, por meio de extensometria linear elétrica, o comportamento biomecânico em protocolos de Brånemark em mandíbulas, modificados pelo conceito All-on-Four, para que seja possível se estabelecer uma correlação entre tensão, deformação e eventos biomecânicos que possam acontecer no tecido ósseo peri-implantar referente a mudança do eixo de instalação de implantes posicionados próximos às extensões em cantlever. Para tanto, foram confeccionados dez modelos experimentais (G1, n=5) e (G2, n=5) homogêneos à base de poliuretano nos quais foram instalados quatro implantes de conexão externa e quatro pilares tipo micro-unit em duas configurações paraos implantes distais. Para o efeito configuração (Configuração) no G1, os implantes foram instalados de forma axial e paralelos entre si. Para o efeito configuração no G2, os dois implantes distais foram instalados em angulação de 300 - sentido distal. O monitoramento das deformações foi obtido em 3 níveis de profundidade (NP) (cervical, médio e profundo) para cada implante, assim como em dois pontos de aplicação de carregamento estático de 50N (PAC) (ponto A em cantlever e ponto B em ponto mediano). Foram coletadas três leituras de micro deformação (ε) para cada extensômetro. Os dados coletados foram submetidos aos testes estatísticos ANOVA e Tukey (α=5%). Para as condições experimentais, os grupos após ensaio de extensometria linear elétrica apresentaram Médias ±DP (ε), para o grupo G1: 149,5±7,7ε (PAC - cantlever); 140,9±6,2ε (PAC – ponto anterior) e para grupo G2: 98,1±6,7ε (PAC - cantlever); 127,9±8,2ε (PAC – ponto anterior). Verificou-se que, no quesito Configuração, os grupos diferem estatisticamente entre si (p=0,0001) e no efeito interação, entre Configuração e PAC, diferem entre si (p=0,0001). A distribuição dos implantes com implantes terminais em 300 interferiram na magnitude da deformação perimplantar, resultando...

This study aimed to evaluate in vitro, the biomechanical behavior in Brånemark protocols modified by the All-on-Four concept, by strain gauge analysis, to establish a correlation between stress, strain and biological events that may occur in the peri-implant bone tissue in two diferent distaly implants configuration. Ten polyurethane experimental models were fabricated (Group 1, n = 5) and (Group 2, n = 5) which were installed four external hex implants and four micro-unit abutments, in two diferent tilting set-up for the distal implants. For the configuration effect in G1, the implants were installed axially and parallel to each other. In G2 group, the two distal implants were tilted 30 degrees. The microstrain data were obtained in 3 deep levels (NP) (cervical, medium and deep) via two linear strain gauges bonded on the mesial and distal surface for each implant. Astatic load of 50 N was applied on two points (PAC) (A - cantlever pointand B - median point). Three microstrain measurements (με) were performed for each strain gauge. Data were analyzed by ANOVA and Tukey’s test for multiple comparisons at 5% level of significance. For the experimental conditions, the groups after testing showed mean ± SD (με) values for G1: 149.5 ± 7.7 με (PAC - cantlever), 140.9 ± 6.2 με (PAC -anterior point) and G2: 98.1 ± 6.7 με (PAC - cantlever), 127.9 ± 8.2 με(PAC - anterior point). It was found that in the question setting groups differ statistically from each other (p = 0.0001) and the interaction effect between PAC and Configuration, differ (p = 0.0001). The tilted implants 30 degrees set-up interfered on the microstrain levels, resulting in a favorable stress reduction in bone tissue as well as a favorable response for bothloading conditions analyzed

Estudo do comportamento biomecânico em protocolos modificados de brånemark(conceito ALL-ON-FOUR): análise por extensometria linear elétrica / Study of Biomechanical behavior in modifyed Brånemark protocols: Strain Gauge analysis

O objetivo deste estudo foi analisar in vitro, por meio de extensometria linear elétrica, o comportamento biomecânico em protocolos de Brånemark em mandíbulas, modificados pelo conceito All-on-Four, para que seja possível se estabelecer uma correlação entre tensão, deformação e eventos biomecânicos que possam acontecer no tecido ósseo peri-implantar referente a mudança do eixo de instalação de implantes posicionados próximos às extensões em cantlever. Para tanto, foram confeccionados dez modelos experimentais (G1, n=5) e (G2, n=5) homogêneos à base de poliuretano nos quais foram instalados quatro implantes de conexão externa e quatro pilares tipo micro-unit em duas configurações paraos implantes distais. Para o efeito configuração (Configuração) no G1, os implantes foram instalados de forma axial e paralelos entre si. Para o efeito configuração no G2, os dois implantes distais foram instalados em angulação de 300 - sentido distal. O monitoramento das deformações foi obtido em 3 níveis de profundidade (NP) (cervical, médio e profundo) para cada implante, assim como em dois pontos de aplicação de carregamento estático de 50N (PAC) (ponto A em cantlever e ponto B em ponto mediano). Foram coletadas três leituras de micro deformação (ε) para cada extensômetro. Os dados coletados foram submetidos aos testes estatísticos ANOVA e Tukey (α=5%). Para as condições experimentais, os grupos após ensaio de extensometria linear elétrica apresentaram Médias ±DP (ε), para o grupo G1: 149,5±7,7ε (PAC - cantlever); 140,9±6,2ε (PAC – ponto anterior) e para grupo G2: 98,1±6,7ε (PAC - cantlever); 127,9±8,2ε (PAC – ponto anterior). Verificou-se que, no quesito Configuração, os grupos diferem estatisticamente entre si (p=0,0001) e no efeito interação, entre Configuração e PAC, diferem entre si (p=0,0001). A distribuição dos implantes com implantes terminais em 300 interferiram na magnitude da deformação perimplantar, resultando...

This study aimed to evaluate in vitro, the biomechanical behavior in Brånemark protocols modified by the All-on-Four concept, by strain gauge analysis, to establish a correlation between stress, strain and biological events that may occur in the peri-implant bone tissue in two diferent distaly implants configuration. Ten polyurethane experimental models were fabricated (Group 1, n = 5) and (Group 2, n = 5) which were installed four external hex implants and four micro-unit abutments, in two diferent tilting set-up for the distal implants. For the configuration effect in G1, the implants were installed axially and parallel to each other. In G2 group, the two distal implants were tilted 30 degrees. The microstrain data were obtained in 3 deep levels (NP) (cervical, medium and deep) via two linear strain gauges bonded on the mesial and distal surface for each implant. Astatic load of 50 N was applied on two points (PAC) (A - cantlever pointand B - median point). Three microstrain measurements (με) were performed for each strain gauge. Data were analyzed by ANOVA and Tukey’s test for multiple comparisons at 5% level of significance. For the experimental conditions, the groups after testing showed mean ± SD (με) values for G1: 149.5 ± 7.7 με (PAC - cantlever), 140.9 ± 6.2 με (PAC -anterior point) and G2: 98.1 ± 6.7 με (PAC - cantlever), 127.9 ± 8.2 με(PAC - anterior point). It was found that in the question setting groups differ statistically from each other (p = 0.0001) and the interaction effect between PAC and Configuration, differ (p = 0.0001). The tilted implants 30 degrees set-up interfered on the microstrain levels, resulting in a favorable stress reduction in bone tissue as well as a favorable response for bothloading conditions analyzed

Uma revisão do conceito all-on-four / All-on-four concept: a literature review

Grandes avanços na história da Implantodontia vêm sendo documentados, porém, existem ainda algumas limitações no tratamento reabilitador com implantes dentários, o que desafia os profissionais a buscarem novas opções de tratamento. Pacientes que apresentam atrofia maxilar necessitam de procedimentos mais complexos, como enxertos ósseos extensos. Uma proposta de tratamento mais simplificada, com menor morbidade e menor tempo de tratamento, foi desenvolvida (Sistema all-on-four). Essa proposta de tratamento se baseia na redução do número de implantes compensada por um maior espaçamento entre eles, além da utilização dos implantes distais inclinados unidos por uma estrutura rígida que favorece a biomecânica e diminui a extensão do cantiléver.

Important progresses in the history of implants have been documented, but there are still some limitations in treatment rehabilitation with dental implants, challenging professionals to search for new treatment alternatives. Patients, with maxillary atrophy demand more complex procedures such as extensive bone grafts. A basic proposal for a treatment with lower morbidity and short-term duration has been developed (The All-on-Four Concept). This is based on reducing the number of implants compensated by an enlarged space between them, besides the use of tilted distal implants connected through a rigid structure that favors biomechanics and reduces cantilever extension.

Planejamento, execução clínica e manutenção deprotocolo all-on-four bimaxilar – relato de caso clínico / Planning, clinical execution, and maintenance of bimaxillary all-on-four protocol – case report

O número, a posição e a disposição dos implantes emum arco desdentado sempre foi motivo de discussãodiante de reabilitações orais fixas. O conceito all-onfourrepresenta uma modalidade de reabilitação detodo um arco edêntulo suportada sobre 04 implantesposicionados estrategicamente, tendo como principaisvantagens a eliminação de enxertos no seiomaxilar, o aumento da área de ancoragem protéticae a redução de tempo e custo do tratamento. Estetrabalho descreve a terapia cirúrgica e protética deuma paciente que utilizava uma reabilitação fixa conjugadaa próteses removíveis com grandes prejuízosbiológicos, funcionais e estéticos. Devido à péssimacondição clínica de todos os dentes remanescentes,optou-se pela exodontia e indicação de um protocoloall-on-four bimaxilar. Reportou-se à literatura científicano sentido de verificar a viabilidade clínica desseprocedimento em longo prazo. Os autores concluíramque o protocolo all-on-four recuperou satisfatoriamenteas funções orais e estéticas da pacienteapós o acompanhamento de 02 anos. Contudo, umcorreto planejamento, execução e manutenção dotratamento são condições imprescindíveis para o sucessodessa modalidade terapêutica.

The number, position, and arrangementof implants (used to rehabilitate) archeshave been discussed in fixed dental prosthesisliterature. The all-on-four protocolrepresents an option to treat entireedentulous arch, and consists on the useof four implants strategically placed tosupport a full arch prosthesis. The mainadvantages are the elimination of the necessityof maxillary sinus grafting, increasedprosthetic anchorage area and time -cost reducing. This paper shows a clinicalcase using the “All-on-Four” technique,describing the surgical and prostheticphases of the therapy. The remaing teethwere extracted due to poor clinical prognosis,and bimaxillary all-on-four protocolwas installed. In the case described,after 2 years of follow-up, the all-on-fourprotocol therapy showed good results,improving the oral functions and aesthetic.Correct planning, execution, andmaintenance are essential conditions forthe long term success.

Three-dimensional finite element analysis on stress distribution of the mandibular implant-supported cantilever prostheses depending on the designs / 대한치과보철학회지

STATEMENT OF PROBLEM: The position and length of cantilever influence on the stress distribution of implants, superstructure and bone. In edentulous mandible, implant-supported cantilever prostheses that based 4 or 6 implants between mental foramens has been attempted. Excessive bite force loaded at cantilever prosthesis causes bone resorption and breakage of superstructure prosthesis around posterior implants. To complement the cantilever length of conventional prosthesis, In 1992, (McCartney) introduced "cantilever - rest - implant" and Malo reported "All-on-Four" in 2003. PURPOSE: Analyze and compare the stress distribution of conventional cantilever prostheses with rest implant and Allon-Four(TM) implant prostheses. MATERIAL AND METHOD: The external loads (300 N vertically, 75 N horizontally) are applied to first molar area. The stress value, stress distribution and aspect of stress dispersion are analyzed by three-dimensional finite element analysis program, ANSYS ver. 10.0. RESULTS: 1. The rest implant and "All-on-Four" implant system are superior to conventional cantilever prostheses to reduce stress on the bone and the superstructure around implants. 2. The rest implant was of the greatest advantage to stress distribution on bone, implant and superstructure. 3. With same number of implants, distally tilted implants are preferred to conventional cantilever prostheses for reducing the length of cantilever.