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)

Prevalence of partial edentulism according to Kennedy and Applegate in patients treated at a university dental clinic in Lambayeque-Peru / Prevalencia de edentulismo parcial según Kennedy y Applegate en pacientes de la clínica odontológica de una universidad de Lambayeque-Perú

Introduction: Edentulism is an irreversible chronic condition that seriously affects the stomatognathic system. Consequently, determining its prevalence may contribute to prioritize preventive and rehabilitative oral health interventions. Objective: To determine the prevalence of partial edentulism according to the Kennedy and Applegate classification in patients attending the Dental Clinic at Universidad San Martín de Porres - Lambayeque Campus, Peru, in the years 2016 and 2017. Materials and methods: A descriptive, retrospective and cross-sectional study was designed. The study comprised 321 clinical records that previously underwent a quality control stage, which included a calibration process (k=0.86). The criteria and rules proposed by Kennedy and Applegate were applied to estimate the prevalence of edentulism in each jaw according to sex; tables of frequency distribution containing percentage results were used. Results: The highest prevalence of partial edentulism in the upper jaw corresponded to Class III (42.4%), followed by Class I (34.6%), and Class II (16.5%). In the lower jaw, the most prevalent were Class I (42.4%), Class III (36.4%), and Class II (15.6%). According to sex, Class III and Class I were the most prevalent in both females and males. Conclusion: Class III and I were the most prevalent in the upper jaw in both females and males; while in the lower jaw, Classes I and III were the most prevalent for both sexes.

El edentulismo se presenta como una alteración irreversible y crónica, que genera consecuencias en el sistema estomatognático, por lo cual es necesario conocer su prevalencia para priorizar intervenciones de salud bucal preventivas y de rehabilitación. Objetivo: Determinar la prevalencia de edentulismo parcial según la clasificación de Kennedy y Applegate en pacientes atendidos en la Clínica Odontológica de la Universidad San Martín de Porres - Filial Lambayeque, en los años 2016 y 2017. Material y Método: Se diseñó un estudio descriptivo, retrospectivo y transversal, con 321 historias clínicas que pasaron previamente por un control de calidad que incluyó un proceso de calibración (k=0.86). Para estimar la prevalencia de edentulismo en cada maxilar y de acuerdo al género, fueron aplicados los criterios y reglas de kennedy y Applegate, utilizando tablas de distribución de frecuencias con resultados porcentuales. Resultados: La mayor prevalencia de edentulismo parcial para maxilar superior corresponde a la Clase III con 42,4%, siguiendo en orden descendente la Clase I con 34.6% y la Clase II con 16.5%. En el maxilar inferior, la más prevalente fue la Clase I con 42,4%, continuando la Clase III con 36.4% y la Clase II con 15.6%. De acuerdo a género, resultaron más prevalentes la Clase III y la Clase I tanto para mujeres como para hombres. Conclusiones: Las clases III y I fueron las más prevalentes en el maxilar superior, tanto para género masculino como femenino; mientras que en el maxilar inferior, fueron las clases I y III las más prevalentes también para ambos géneros.

Immediate small-diameter implants as abutments for an overdenture in the edentulous atrophic mandible: report of immersion endoscopic bone in vivo, and histologic bone-implant evaluation after 6 months of function / Implantes de pequeño diámetro como soporte inmediato de sobredentaduras en hueso alveolar mandibular atrófico: reporte de endoscopía de inmersion in vivo y evaluación histológica a los 6 meses de función

The aim of this report was to endoscopically evaluate bone quality in vivo in the immediate installation of temporary small-diameter implants, and again after 6 months of function, through an attachments system for overdenture, in the atrophic mandible of a patient. We also histologically evaluated bone-implant interaction in these temporary small-diameter implants, once the success of the osseointegration of the submerged implants was guaranteed. A patient received a total of 6 implants in the atrophic mandible, two of which were immediately loaded with a provisional prosthesis, and four were left to heal in a submerged way. Further, an immersion endoscopic evaluation was performed during bone drilling, and this showed a compact bone structure with limited vascularization and predominantly cortical structure.This immediate loading protocol involving an overdenture retained by two small-diameter implants of 2.9 mm in the atrophic mandible proved to be successful after 6 months of loading. Clinical and histologic osseointegration was consistently achieved for both of the retrieved immediately loaded implants. This modality allows the patient to be restored with a stable, functional, and aesthetic prosthesis during the osseointegration period of submerged implants and soft-tissue healing, before the removal of the provisional implants. The histological evaluation of bone-implant contact found that the space between the implant threads closer to the surface was filled with woven bone and lamellar bone, but the tissue in contact with the cervical portion of the implants was compatible with cortical bone organization. Also, the newly formed bone has a regular cell distribution and characteristics of advanced maturation after 6 months of function in the atrophic mandible. Anchored overdentures in 2 to 4 small-diameter implants (2.9 mm) for edentulous patients with severe atrophy of the mandible with cortical bone would be a minimally invasive alternative.

Comparación entre la piezocirugía y los instrumentos rotativos convencionales en la lateralización del nervio dentario inferior / Comparison between the piezosurgery and the conventional rotary surgery in the lateralization of the inferior alveolar nerve

Introducción: la rehabilitación de pacientes desdentados mandibulares posteriores con implantes osteointegrados, se vuelve difícil cuando la cresta alveolar presenta una atrofia severa debido al recorrido superficial del canal mandibular. La lateralización del nervio dentario inferior es una alternativa terapéutica que posibilita la colocación de implantes convencionales y cortos en esta región. Objetivo: comparar la facilidad, efectividad y seguridad de la técnica quirúrgica convencional, realizada con fresas quirúrgicas, y la piezocirugía en la lateralización del nervio dentario inferior. Presentación del caso: paciente con ausencia bilateral de los molares inferiores y cresta alveolar atrófica fue tratada mediante lateralización del nervio dentario inferior y colocación simultánea de implantes. En el lado izquierdo, la lateralización fue realizada con fresas y en el lado derecho, con motor piezoeléctrico. Fue posible observar que la piezocirugía facilitó la técnica quirúrgica, y consecuentemente disminuyó el tiempo operatorio. A la vez, produjo una osteotomía más regular y con menos sangrado, lo cual mejoró la visualización del campo operatorio. Finalmente, el daño neural inmediato fue menor en el lado tratado con motor piezoeléctrico y con recuperación más rápida. Después de 3 meses de seguimiento, los implantes en ambos lados no presentaban pérdida ósea. Conclusiones: el uso del motor piezoeléctrico trajo más beneficios durante la lateralización del nervio dentario inferior, por la simplificación de la técnica quirúrgica y la reducción del sangrado y del daño neural en comparación con el uso de fresas convencionales(AU)

Introduction: the rehabilitation of edentulous posterior mandibular patients with bone-integrated implants becomes difficult when the alveolar crest presents a severe atrophy due to the superficial course of the mandibular canal. The inferior alveolar nerve lateralization is a therapeutic alternative that allows the placement of conventional and short implants in this region. Objective: to compare the easiness, effectiveness, and safety of the conventional surgical technique, performed with surgical drills, and piezosurgery in the lateralization of the inferior alveolar nerve. Case presentation: a patient with bilateral absence of the lower molars and atrophic alveolar crest was treated by lateralization of the inferior alveolar nerve and simultaneous implant placement. On the left side, the lateralization was made with drills and on the right side, with an electric piezotome. It was possible to observe that the piezosurgery facilitated the surgical technique, and consequently decreased the operative time. At the same time, it produced a more regular osteotomy and with less bleeding, which improved the visualization of the operative field. Finally, the immediate neural damage was lower on the side treated with the electric piezotome and with faster recovery. After 3 months of follow-up, the implants on both sides did not show bone loss. Conclusions: the use of the electric piezotome brought more benefits during the lateralization of the inferior alveolar nerve, by the simplification of the surgical technique and the reduction of bleeding and neural damage in comparison with the use of conventional drills(AU)

Implantes de altura reduzida devem ser esplintados em região posterior de mandíbula? / Should implants with reduced height be splinted in the posterior mandible?

A reabilitação de pacientes parcialmente desdentados é um tratamento viável e com excelente prognóstico. Todavia, a disponibilidade óssea em altura é um fator crucial para o sucesso desse tratamento. O levantamento de seio maxilar, apesar da baixa qualidade óssea da maxila posterior, é considerado um procedimento bastante previsível. Entretanto, técnicas reconstrutivas em mandíbula não possuem a mesma previsibilidade, além de apresentar maior morbidade pós-operatória. Apesar da alta previsibilidade dos implantes com altura reduzida, poucos são os estudos que avaliam a real necessidade da esplintagem do mesmo em mandíbula posterior atrófica. Dessa forma, o objetivo do presente estudo foi avaliar a necessidade de um implante curto ser esplintado a outro. Após análise criteriosa da literatura concluiu-se que os implantes com altura reduzida unitários apresentam igual previsibilidade em relação ao esplintado. Todavia, a heterogeneidade dos estudos e a falta de ensaios clínicos randomizados justifica a elaboração de novas pesquisas.(AU)

Rehabilitation of partially edentulous patients is a viable treatment with an excellent prognosis. However, bone height availability is a crucial factor in the treatment success. The maxillary sinus lift, despite poor bone quality of posterior maxilla, is considered a predictable procedure. However, reconstructive techniques in the mandible do not have the same predictability and present more postoperative morbidity. Despite the high predictability of short implants, there are few studies evaluating the real necessity for splinting implants in posterior atrophic mandible. Thus, the objective of the present study was to evaluate the need for a short implant to be splinted to another. After analysis of the literature, this review concluded that unitary short implants presented equal predictability compared to splinted implants. However, the heterogeneity of the studies and the lack of randomized clinical trials justify the development of new research.(AU)

Carga inmediata con rehabilitación definitiva en maxilar inferior: reporte de caso / Immediate load with definitive prosthesis in the lower jaw: a case report

El objetivo de este artículo es presentar un protocolo simplificado para la instalación inmediata de una prótesis definitiva sobre 4 implantes mandibulares. Fue realizado en una paciente de sexo femenino de 72 años, desdentada total. Se inició el tratamiento con la confección de una prótesis removible convencional hasta la prueba de articulación dentaria, a partir de lo cual se obtuvo una guía multifuncional. En la cirugía se instalaron 4 implantes Strong SW (SIN®, Sao Paulo, Brasil) entre agujeros mentonianos. Se atornillaron pilares Mini-Abutment y se tomó la impresión utilizando la guía. Al segundo día se probó la estructura metálica con el enfilado dentario en cera y al tercer día se realizó la instalación de la prótesis terminada con torque manual. A los 10 días se retiró la sutura y se dio torque a los tornillos protésicos (10 N/cm). La paciente ha asistido a controles, sin presentar complicaciones hasta este momento.

The aim of this paper is to present a simplified protocol for immediate installation of a definitive prosthesis over four jaw implants. This was performed on a totally edentulous female patient of 72 years. The treatment was initiated with the preparation of a conventional removable prosthesis until the dental articulation test from which a multifunctional guide was obtained. At surgery, four Strong SW (SIN®, Sao Paulo, Brazil) implants were installed between mental foramen. Mini-Abutments were screwed and the impression was made using the guide. On the second day the metal structure was tested with the dental articulation in wax and on the third day the definitive prosthesis was installed with manual torque. The suture was removed 10 days after surgery, and the torque was given to prosthetic screws (10 N/cm). The patient was followed up every 6 months, with no complications so far.

Utilização de osso homólogo em reconstrução parcial de maxila: relato de caso clínico / Use of homologous bone in partial reconstruction of the maxilla: a case report

O presente trabalho tem como objetivo descrever um caso clínico de utilização de enxertos ósseos homólogos na Odontologia, para reconstrução parcial de uma maxila. A diminuição da morbidade dos enxertos, quando comparados com a necessidade de um segundo sítio cirúrgico intrabucal ou extrabucal para utilização de osso autógeno, levou à escolha dessa alternativa para reconstrução óssea do paciente e se mostrou capaz de receber implantes e reabilitação protética com segurança. Métodos: foi utilizada uma porção de osso homólogo (crista ilíaca) oriundo do banco de ossos da Universidade Federal do Paraná. Parte do enxerto foi triturada e utilizada para preencher o seio maxilar, e parte foi colocada em aposição na região anterior. Resultados: a realização, após oito meses, de um exame tomográfico da região enxertada mostrou disponibilidade óssea suficiente para receber oito implantes com carga imediata. Conclusão: o resultado do enxerto com osso homólogo conseguido no caso clínico permitiu que fossem colocados oito implantes nas áreas que receberam enxertos e mostrou-se capaz de receber forças mastigatórias, estáveis e assintomáticos, com carga imediata e durante 15 meses de acompanhamento...

This study aims to report the completion of a clinical case using homologous bone graft for partial reconstruction of a maxilla. The grafts decreased morbidity, when compared to the need for a second intra- or extra oral surgical site to use autogenous bone, made us choose this alternative bone reconstruction procedure. The patient proved to have received implants and prosthetic rehabilitation safely. Methods: A portion of homologous bone (iliac crest) derived from the bone bank of Universidade Federal do Paraná (UFPR) was used. Part of the graft was ground and used to fill the maxillary sinus; additionally, it was placed in opposition to the anterior region. Results: A CT scan of the grafted area was obtained eight months after surgery and showed enough bone availability to receive eight immediately loaded implants. Conclusion: The results of homologous bone graft achieved in the clinical case reported herein allowed eight implants to be placed in areas that received grafts and proved capable of receiving masticatory forces, stable and asymptomatic, with immediate loading and during 15 months of follow-up...

Prevalência da utilização de implantes curtos em maxilares: estudo piloto retrospectivo / Prevalence of short implants use in the jaws: a retrospective pilot study

A instalação de implantes tem se tornado o tratamento recomendado para a reposição em edêntulos. Pesquisas na área da Implantodontia têm objetivado desenvolver procedimentos rápidos, controlados e que resultem em maior conforto e previsibilidade ao paciente e ao profissional. Nessas circunstâncias, surgiu o desenvolvimento de implantes curtos, substituindo os implantes convencionais quando há uma limitação para a implantação desse, representando uma alternativa viável, simples e previsível. Para se verificar a prevalência de utilização dos implantes curtos, sobre uma quantidade preestabelecida de prontuários, foram utilizados prontuários de diferentes clínicas e cursos de especialização, entre 2005 e 2012. Verificou-se quantos desses eram curtos (ou seja, com tamanho de 8,5mm ou 10mm), o tamanho dos implantes, a região em que foram implantados, o sexo e a idade dos pacientes. Dos 82 prontuários analisados, foram obtidos 459 implantes; desses, a maioria (79%) foi instalada em pacientes do sexo feminino. Desses implantes, 48,6% eram de 10mm e 14,8% eram de 8,5mm. Para ambos os tamanhos, a idade de maior prevalência foi entre 50 e 59 anos. A proporção de utilização de implantes curtos, comparados aos longos convencionais, aumentou nos últimos anos, em decorrência das novas pesquisas, e vêm sendo indicados em diversas circunstâncias, mostrando ser uma técnica segura, previsível, com menor custo, sem necessidade de múltiplos procedimentos cirúrgicos, além de preservar as estruturas anatômicas preexistentes e ter boa aceitação pelos implantodontistas e pacientes...

Implant placement has become the recommended treatment for rehabilitation of edentulouspatients. Research in Implantology aims to develop rapid controlled procedures that provide patients and clinicians with greater comfort and predictability. In these circumstances, short implants were developed to replace conventional implant limited placement, thereby representing a feasible, simple and predictable alternative. To determine the prevalence of short implants use on a previously established sample of dental records, the latter were obtained from different dental offices and specialization courses between 2005 and 2012. The following was assessed: number of short implants (8.5-mm or 10-mm long), size of implants, the region where they were placed, as well as patients’ sex and age. Of the 82 dental records analyzed, 459 implants were obtained; the majority (79%) of them was placed in female patients, 48.6% were 10-mm long and 14.8% were 8.5-mm long. For both implant sizes, the most prevalent age group was between 50 and 59 years old. The use of short implants, when compared to the use of conventional long ones, increased in recent years due to new research. They are recommended in different circumstances and have proved to be a safe, predictable, less expensive technique without the need for multiple surgery, in addition to preserving patient’s preexisting anatomic structures and being well received by patients and implant dentists...

Overdenture com carga imediata: relato de caso clínico / Overdenture with immediate loading: a case report

Introdução: com o advento da Implantodontia, surgiram novos horizontes para o tratamento de pacientes com edentulismo. Um dos exemplos são as overdentures retidas por implantes osseointegráveis, representando uma modalidade eficiente no tratamento do edentulismo total. As overdentures são uma alternativa atraente, em função de sua simplicidade e de seu custo relativamente baixo. Apresentam vantagens em relação às próteses totais, sobretudo no que se refere à eficiência mastigatória, conforto e satisfação do paciente. Objetivo: descrever um caso clínico de overdenture com carga imediata, apresentando mais uma possibilidade dereabilitação bucal na Implantodontia. Métodos: foram abordados os principais cuidados e vantagens da técnica. Conclusão: foi possível concluir, com base no relato apresentado, que a overdenture com carga imediata apresenta algumas vantagens, como o tratamento sendo realizado de forma rápida, com custo baixo e acarretando uma melhoria na qualidade de vida do paciente.

Introduction: The advent of Implantodontics has opened up the horizons in edentulous patients treatment. Osseointegrated implant-supported overdentures are one example of a successful treatment modality for complete edentulism. They are an attractive alternative due to beingsimple and of relatively low cost. They also have advantages over the use of complete dentures, especially with regard to masticatory efficiency and patient’s comfort and satisfaction. Objective: to describe a case of overdenture with immediate loading to show an alternative approach for oralrehabilitation. Methods: The technique main advantages were presented. Conclusion: The study concluded that overdenture with immediate loading has some advantages, such as reduced treatment time, low cost, and improved patients’s quality of life.

Reabilitação de maxila edêntula com prótese fixa implantossuportada: relato de caso / Rehabilitation of edentulous maxilla with implant-supported fixed prosthesis: a case report

Introdução: os problemas funcionais, estéticos e psicológicos decorrentes do edentulismo têm levado a uma busca crescente por reabilitação bucal com próteses sobre implantes. Esse tipo de reabilitação necessita de um planejamento meticuloso, especialmente para os casos de maxila edêntula com prótese fixa sobre implantes, em decorrência da anatomia dessa região. Objetivo: o objetivo do presente caso clínico é descrever a reabilitação de uma maxila edêntula com prótese total fixa implantossuportada, cuja infraestrutura recebeu elementos metalocerâmicos cimentados individualmente.

Introduction: Functional, aesthetic and psychological issues arising from edentulism have led to a growing search for oral rehabilitation with implant-supported prostheses. This type of rehabilitation requires detailed planning, especially for treating edentulous maxilla with implantsupported fixed prostheses due to the anatomy of this region. Objective: The aim of this case report is to describe the rehabilitation of an edentulous maxilla with implantsupported full fixed prosthesis of which framework received metal-ceramic elements individually cemented.

Reabilitação de maxila em carga imediata utilizando técnica guiada flapless, baseada em planejamento virtual pré-cirúrgico: relato de caso clínico / Rehabilitation of the maxilla with computer-assisted flapless surgery according to virtual preoperative planning: A case report

A técnica da cirurgia guiada, associada à tecnologia CAD/CAM, auxilia na busca de precisão na instalação de implantes osseointegráveis, pois segue um planejamento virtual que permite a visualização em software da relação da necessidade protética com a quantidade óssea disponível. Objetivo: o objetivo desse trabalho é relatar um caso de reabilitação de arcada superior com utilização do sistema NeoGuide (Neodent, Curitiba/PR), com técnica guiada flapless em carga imediata. Métodos: após o preparo pré-tomográfico e o planejamento virtual, foram instalados oito implantes Titamax EX cone-morse (Neodent) com a utilização de um guia cirúrgico prototipado. Após a instalação dos implantes, foi realizado exame radiográfico panorâmico e tomografia computadorizada. Em seguida, foi instalada uma prótese fixa implantossuportada. Conclusão: a utilização de técnica guiada flapless em carga imediata mostrou-se um recurso valioso no tratamento de reabilitações de arcadas superiores edêntulas, com redução do tempo cirúrgico e diminuição dos sintomas pós-operatórios, como dor, edema e inflamação.

Computer-guided surgery combined with CAD/CAM technology is a useful technique for placement of osseointegrated dental implants with utmost accuracy, since it employs virtual planning technology which allows visualization by a computer software of the relationship between one’s prosthetic needs and the amount of bone available. Objective: The aim of this studywas to report a case of maxillary rehabilitation with the use of the Neoguide system (Neodent®,Curitiba, Brazil), with the aid of computer-guided flapless technique and immediate loading. Methods: after pre tomographic preparation and virtual planning, eight Titamax EX Morse taperimplants (Neodent®, Curitiba, Brazil) were placed using a prototyped surgical guide. After implantplacement, panoramic radiographs and CT scans were performed. Subsequently, a fixed implant supported denture was installed. Conclusion: The use of computer-guided flapless surgery with immediate loading proved a valuable resource in maxillary rehabilitation, with reduced surgical time and decreased post-operative symptoms such as pain, swelling and inflammation.

Reabilitação de maxila atrófica sem uso de abordagem reconstrutiva: relato de caso / Rehabilitation of atrophic maxilla without a reconstructive approach:a case report

A reabilitação bucal de pacientes edêntulos, por meio do uso de próteses totais fixas, comumente envolve procedimentos reconstrutivos prévios, haja vista que o rebordo ósseo residual não apresenta as dimensões mínimas requeridas para a instalação de implantes de diâmetro regular na região planejada. Fatores como o custo elevado e o medo de procedimentos cirúrgicos adicionais fazem com que alguns idosos, mesmo insatisfeitos com a instabilidade da prótese removível, resistam ao tratamento com implantes dentários. Objetivo: dessa forma, o presente estudo tem como objetivo relatar um caso de reabilitação bucal com prótese total implantossuportada, por meio da instalação de implantes de diâmetro reduzido (3,3mm) em maxila severamente atrófica, sem a utilização de enxertos ou abordagens reconstrutivas. Os 8 implantes, instalados com abordagem palatina nos sítios previamente planejados, permaneceram submersos por 45 dias, quando foi dado o início da adequação gengival e etapas protéticas. A prótese definitiva foi instalada 65 dias após a cirurgia. Nenhuma intercorrência foi registrada durante 6 meses de acompanhamento. Nota-se que os implantes de diâmetro reduzido surgem como uma alternativa simples e rápida à realização de procedimentos de aumento ósseo horizontal, e podem ser utilizados com segurança como forma de retenção para próteses fixas, tornando-se uma solução eficiente e de menor custo para pacientes edêntulos que desejam reduzir os problemas relacionados à instabilidade de próteses totais removíveis...

Oral rehabilitation of edentulous patients using fixed prostheses commonlyinvolves previous reconstructive procedures, since the residual ridge does not have the minimumdimensions required for installation of standard diameter implants in the planned site. Factors suchas high cost and fear of additional surgical procedures make some elderly, even those who are dissatisfiedwith the instability of removable prosthesis, hesitant to treatment with dental implants.Objective: This study aims to report a case of oral rehabilitation with fixed dentures supported byimplants of reduced diameter (3.3 mm) in severely atrophic maxilla without the use of grafts or reconstructiveapproaches. The eight implants, installed with palatal approach at previously plannedsites, remained submerged for 45 days when soft tissue adjustment and prosthetic procedures werestarted. The definitive prosthesis was installed 65 days after surgery. Results: No intercurrence wasregistered after 6 months of follow-up. Small diameter implants appear as a simple and fast alternativefor horizontal bone augmentation procedures. Additionally, they can be safely used for retentionof fixed prosthesis, and prove to be an efficient and low-cost solution for edentulous patientswho wish to minimize problems related to the instability of removable dentures...

Técnica simplificada en la rehabilitación del desdentado / Simplified technique for the rehabilitation of the edentulous

En esta comunicación se presenta una técnica simplificada de rehabilitación del desdentado total por medio de prótesis removible en que solamente en tres citas clínicas se logra el objetivo del tratamiento. Este logro es posible de ser llevado a cabo por medio del uso de un material fotopolimerizable con el que se realiza la cubeta individual directamente en boca, sin la confección de modelos preliminares, permitiendo de este modo efectuar la toma de impresiones preliminares, definitivas y relaciones intermaxilares en una sola sesión.

In this paper we present a simplified rehabilitation technique for the edentulous through removable prosthesis that achieve the goal of the treatment in only three clinical appointments. This accomplishment is possible through the use of a photopolymerizable material, performing an impression tray directly in the mouth without making any preliminary models; it thereby enables to take preliminary and definitive impressions, and intermaxillary relations in a single session.

Función protésica inmediata con técnica all on-4 mandibular: primer reporte al 1er año de carga inmediata / Immediate prosthetic function with all on-4 mandibular technique: first report after 1 year of immediate loading

Propósito: El objetivo del presente estudio prospectivo es la observación del comportamiento de la función protésica inmediata sobre implantes axiales en combinación con implante inclinados posteriores distribuidos poligonalmente en mandíbulas edéntulas. Material y Métodos: De un grupo de 28 individuos desdentados completos mandibulares se observaron 25 individuos distribuidos en 13 hombres y 12 mujeres con un promedio de edad de 57.8 años, bajo la modalidad de rehabilitación protésica implanto asistida en distribución poligonal de arco completo híbrida con una barra de titanio soldada de sección circular de 2mm de grosor instalada a las 48 hrs. de realizada la inserción de los implantes, la cual a los 3 meses fue cambiado por una estructura colada en titanio como prótesis definitiva. Durante el periodo de observación se evaluó la tasa de éxito implantario, las complicaciones biológicas y mecánicas por un periodo inicial de 1 año. El protocolo se inicia con la valoración y confección de un enfilado dentario de prótesis completa convencional, el que, una vez aceptado por el paciente, es duplicado para la confección de una guía tomográfica, con la cual se procederá a la toma de un scanner dental, relacionado las necesidades protésicas y la distribución implantaria en relación a la emergencia y prolongación del nervio mentoniano, altura del foramen mentoniano y forma de la mandíbula. Todos los pacientes fueron operados elevando un colgajo de espesor total y utilizando la guía quirúrgica All on-4 (Nobel Biocare) bajo sedación endovenosa y utilizando una cubeta multifuncional para la toma de registros maxilomandibulares e implantarios en el proceso de carga imediata...

Purpose: The purpose of this prospective study is the observation of the behaviour of immediate occlusal loading with axial implants in combination with posterior tilted implants in edentulous mandibles polygonally distributed. Methods: From a group of 28 individuals with complete edentulous mandible, 25 individuals distributed in 13 men and 12 women were observed with an average age of 57.8 years, under the implant-assisted prosthetic rehabilitation modality in full arch polygonal hybrid distribution with a welded 2mm-thick titanium bar of circular section installed 48 hrs after insertion of the implant, which was changed after 3 months to a titanium casting structure as definitive prosthesis. During the observation period, the implant success rate, biological and mechanical complications were assessed for an initial period of 1 year. The protocol begins with the assessment and preparation of the lining of a conventional complete denture. Once accepted by the patient, it is doubled to make a tomographic guidance, used to take a dental scanner, The prosthetic needs and implant distribution are related to the emergence and continuation of the mental nerve, mental foramen and height and shape of the jaw. All patients were operated lifting a full-thickness flap and using the All on-4 (Nobel Biocare) surgical guide under intravenous sedation, and a flexible bucket for the maxillomandibular and implant records in the immediate loading...

Stress analysis of different configurations of 3 implants to support a fixed prosthesis in an edentulous jaw

This study's aims was to evaluate the stress distribution in a mandibular implant-supported prosthesis and peri-implant bone considering implant quantity, diameter and position using linear 3-D finite element analysis. Models of an anterior jaw comprised 4 groups according to implant quantity, diameter, and position: control group C, 5 regular implants; R, 3 regular implants; W, 3 wide implants; and DTR, 3 regular implants with the distal ones tilted 30º distally. The cantilever was loaded with an axial load of 50 N. Data was evaluated using von Mises stress on implants and maximum principal stress and microstrain on the bone. The W group showed the lowest value of maximum principal stress in peri-implant bone of the loaded side (4.64 MPa) when compared to C (5.27 MPa), DTR (5.94 MPa), and R (11.12 MPa). Lower stress values in the loaded implants were observed in the experimental groups when compared to the C group. However, the unloaded implants presented opposite results. All the screws of the W group presented lower stress values when compared to the C group. However, the R and DTR groups presented an increase in stress values with the exception of the loaded screw. A reduction in the number of implants associated with wider implants reduced the stress in the bone and prosthetic components.

Success and survival rates of mandibular overdentures supported by two or four implants: a systematic review

This systematic review evaluated the influence played by the number of implants on the results of rehabilitation treatment with mandibular overdentures on 2 or 4 implants. The literature search was conducted using PubMed, Embase and Cochrane databases. Specific terms were used in performing a search from January 1980 to January 2013. The search strategy was applied by two reviewers who extracted the data and compared the results. Discrepancies were resolved by discussion. Great heterogeneity was seen among the selected studies, in regard to survival rates, prosthesis failure and function rates. A medium degree of quality and methodological consistency was found in one study, and no studies showed a high degree. When considering the prosthesis success rate for 2 implants, there was a variation of 23% to 100%. However, when considering the survival rate, the result was 92% to 100%. For 4 implants, prosthesis survival rates showed less variation, i.e., 97.7% to 100%. Ball attachments were the most common type of abutment for 2 implants; however, there was a higher prevalence of bar abutments for 4 implants. Rehabilitations with 2 implants showed more complications and required more maintenance according to the connection type. Given the limitations of this review, mandibular overdentures with 4 implants showed better results with respect to survival and success rates, especially those with a bar connection. Further studies comparing these two treatment types are necessary to improve the scientific evidence in this area.

Reporte clínico: registro piezográfico de la zona neutra, en un paciente con espasmos musculares involuntarios / Clinical report: piezographyc record of the neutral zone in a complete edentulous patient with involuntary muscle spasms

Toda función del sistema estomatognático involucra la acción sinérgica de la musculatura paraprotética, representada por estructuras complejas tales como lengua, labios, mejillas y piso de boca. Al rehabilitar a través de prótesis completas no siempre se considera la influencia de la dinámica muscular, y menos aún cuando alguna de estas estructuras presenten alguna patología, por ejemplo, el compromiso del nervio facial que genera espasmos musculares involuntarios. En tal situación, la ubicación de los dientes y la forma de las superficies pulidas pueden llegar a ser decisivos entre éxito o fracaso de la rehabilitación. Se sabe que los implantes oseointegrados proveen retención, soporte y estabilidad, sin embargo existen situaciones especiales en que no es posible acceder a este tipo de tratamiento, tanto por razones médico quirúrgicas o costos asociados. En este estudio se ha utilizado un registro Piezográfico de la Zona Neutra en un paciente con compromiso del nervio facial que genera espasmos musculares involuntarios del lado afectado, obteniéndose una rehabilitación protésica basada en la apropiada relación entre superficie protésica externa y tejidos circundantes, mejorando requisitos funcionales tales como retención y estabilidad. Se ha utilizado el sistema de tomografía computarizada Cone Beam, con el objetivo de evidenciar el registro piezográfico. Los resultados obtenidos con estas prótesis piezográficas demuestran ser superior en factores como comodidad y fonoarticulación pero inferior en eficiencia masticatoria comparada con la técnica convencional.

Every function of the stomatognathic system involves the synergistic action of the musculature around the prosthesis, consisting of complex and individual structures such as tongue, lips, cheeks and mouth floor. When planning and making complete prostheses, the muscular dynamic is not always considered. This can generate instability of the device during function, the location of the artificial teeth is made arbitrarily on the top and middle parts of the flange, and the configuration of the polished areas is made according to mechanistic concepts. This factor takes more relevance in patients with severe atrophy of their residual flanges, where the prosthetic stability can be a decisive factor between the success or failure of the rehabilitation. It is known that the osseointegrated implants provide retention, support and stability. However, there are special situations in which it is not possible to access to this type of treatment, both for medical surgical reasons or associated costs. In this study, a Piezographyc record of the Neutral Zone was used in a patient with facial nerve involvement generating involuntary muscle spasms of the affected side. A prosthetic rehabilitation based on the appropriate relation between external prosthetic surface and surrounding tissues was obtained, improving functional requirements such as retention and stability. The computerized tomographic Cone Beam system was used, with the objective to show the piezographic record. The results obtained with these piezographic prostheses prove to be superior in factors like comfort and speech articulation, but inferior in masticatory efficiency, where the conventional technique is still better.

Virtual planning and construction of prototyped surgical guide in implant surgery with maxillary sinus bone graft

PURPOSE: To evaluate the efficacy of associating techniques of bone grafting in the maxillary sinus with the use of a prototyped surgical guide for planning and positioning dental implants in total edentulous maxillae, rehabilitated after six months. METHODS: Eight patients consecutives with totally edentulous maxilla presenting few remaining bone in the posterior alveolar ridge, associated with pneumatization of the maxillary sinus were selected. Twenty eight Brånemark RP 10mm implants were installed in 14 maxillary sinuses. The surgical planning for the implant installation was performed with the DentalSlice software by means of a computerized tomography. The obtained images were used for building a surgical guide that, placed over the maxilla, showed the exact position for the implants installation (prototyped surgical guide). The portion of the implants that went into the maxillary sinus was covered by an autogenous bone graft. RESULTS: The patients were re-evaluated six months after the surgery and a 100% success rate was achieved. All of the implants presented no mobility or symptoms, permitting an oral rehabilitation with total fixed screw-retained prosthesis over the implants. CONCLUSION: The technique of associating implants and bone graft in the maxillary sinus aided by a prototyped guide planned on DentalSlice has showed itself efficient for positioning implants and for quantifying and locating the bone graft.

Stress Distribution in Co-Cr Implant Frameworks after Laser or TIG Welding

Lack of passivity has been associated with biomechanical problems in implant-supported prosthesis. The aim of this study was to evaluate the passivity of three techniques to fabricate an implant framework from a Co-Cr alloy by photoelasticity. The model was obtained from a steel die simulating an edentulous mandible with 4 external hexagon analog implants with a standard platform. On this model, five frameworks were fabricated for each group: a monoblock framework (control), laser and TIG welding frameworks. The photoelastic model was made from a flexible epoxy resin. On the photoelastic analysis, the frameworks were bolted onto the model for the verification of maximum shear stress at 34 selected points around the implants and 5 points in the middle of the model. The stresses were compared all over the photoelastic model, between the right, left, and center regions and between the cervical and apical regions. The values were subjected to two-way ANOVA, and Tukey's test (α=0.05). There was no significant difference among the groups and studied areas (p>0.05). It was concluded that the stresses generated around the implants were similar for all techniques.

Resumo A falta de passividade tem sido associada a problemas biomecânicos em próteses implantossuportadas. A proposta deste estudo foi avaliar, por meio da fotoelasticidade, a influência de três diferentes de fabricação de infraestrutura em liga de Co-Cr na passividade destas. O modelo foi obtido a partir de uma matriz de aço simulando uma mandíbula edêntula com 4 análogos de implantes de hexágono externo com plataforma padrão. Neste modelo, foram confeccionados cinco amostras para cada grupo: infraestruturas em monobloco, infraestruturas soldadas a laser e soldadas a TIG. O modelo fotoelástico foi feito com uma resina epóxi flexível (GIII, Polipox Industria e Comercio Ltda.). Na análise fotoelástica, as infraestruturas foram aparafusadas no modelo para a verificação da tensão de cisalhante máxima em 34 pontos selecionados ao redor dos implantes e 5 pontos na região média do modelo. Foram comparadas as tensões em todo o modelo fotoelástico, entre as regiões direita, esquerda e centro e também entre as regiões cervical e apical. Os valores foram submetidos à análise de variância a dois critérios, seguido pelo teste de Tukey (α=0,05). Os resultados não mostraram diferença significativa entre as tensões presentes nos grupos e nas áreas estudadas. Conclui-seque as tensões geradas ao redor dos implantes foram semelhantes entre as diferentes técnicas de confecção e entre todas as regiões analisadas. .

Salvation of a severely resorbed mandibular ridge with a neutral zone technique.

The objective of any prosthodontic service is to restore the patient to normal function, contour, esthetics, speech, and health. An optimum denture stability is difficult to achieve in conventional complete dentures. This problem is more magnified in mandibular dentures. The design of prostheses to replace lost teeth and resorbed ridges is largely determined by the position and amount of morphological change in the denture-bearing area of the jaws. A neutral zone may be defined as the space where, during function, the forces of the lips and cheeks pressing inward neutralize the forces of the tongue pressing outward. The neutral zone concept implies acquired muscle control, especially by tongue, lips, and cheeks toward the denture stability. Advocates of the neutral zone concept agree that a lack of favorable leverage is observed when teeth are positioned directly over the ridge. By employing the neutral zone concept, the dislodging muscle energy can easily become a retentive and stabilizing force.