Prosthetic maintenance assessment for implant fixed complete dentures and implant overdentures: a randomized clinical trial / Avaliação da manutenção protética para próteses totais fixas suportadas por implantes e Overdentures: um ensaio clínico randomizado

Objective: The rehabilitation choice for the edentulous patients usually lies between the fixed and removable prosthetic options. The treatment decisions are affected by many factors where complications and maintenance needs are both considered crucial factors, in addition to the cost effectiveness of the chosen treatment. Material and Methods: This study was applied on 44 edentulous patients, where 22 patient for each group were enrolled in the outpatient clinic of prosthodontics, Cairo University as per a set of eligibility criteria. Four inter-foraminal implants were installed for all eligible participants. Three months later, healing abutments were used for soft tissue preparation prior to the fabrication of the final prosthesis. A prosthetic treatment option was then randomly allocated to obtain two equal groups via computer generated randomization program; Group. A received telescopic implant overdentures, and Group. B received screw retained dentures. All Complications (Screw loosening or fracture, tooth or denture base fracture and mucositis) were reported after overdenture insertion along the follow up period (1, 6, 9 and 12 months respectively). Results: The frequency of the screw loosening for hybrid overdentures where (59.1%) compared to (27.3%) of telescopic prosthesis at 12 months follow up period (p=0.035), mucositis reporting at 6m interval had shown the highest frequency in both groups (Group A (54.5%), Group B (81.8%), (p=0.045), all other reported complications that lack statistical significance either within the same group or between both groups at different time intervals. Conclusion: Both treatment modalities; telescopic implant overdenture and hybrid fixed screw-retained are reliable for restoring the completely edentulous arches, the decision whether to make a fixed or removable implant denture shall be guided with the patient preference together with the dentist assessment in relation (AU)

Objetivo: A escolha da reabilitação para pacientes edêntulos geralmente recai entre próteses fixas e removíveis. As decisões de tratamento são afetadas por muitos fatores onde as complicações e as necessidades de manutenção são consideradas critérios cruciais, além do custo-efetividade do tratamento escolhido. Material e Métodos: Este estudo foi aplicado em 44 pacientes edêntulos, onde 22 pacientes para cada grupo foram matriculados no ambulatório de prótese dentária da Universidade do Cairo de acordo com um conjunto de critérios de elegibilidade. Quatro implantes interforaminais foram instalados para todos os participantes elegíveis. Três meses depois, pilares de cicatrização foram utilizados para preparação dos tecidos moles antes da fabricação da prótese final. Uma opção de tratamento protético foi então alocada aleatoriamente para obter dois grupos iguais por meio de andomização gerada através programa de computador. O Grupo A recebeu overdentures de implantes telescópicos e o Grupo B recebeu dentaduras fixas parafusadas sobre os implantes. Todas as complicações (afrouxamento ou fratura do parafuso, fratura da base do dente ou da prótese e mucosite) foram relatadas após a inserção da overdentures ao longo do período de acompanhamento (1, 6, 9 e 12 meses, respectivamente). Resultados: A frequência do afrouxamento do parafuso para Overdentures híbridas (59,1%) em comparação com (27,3%) da prótese telescópica no período de acompanhamento de 12 meses (p=0,035), o relato de mucosite no intervalo de 6 meses mostrou a maior frequência em ambos os grupos (Grupo A (54,5%), Grupo B (81,8%), p=0,045, todas as outras complicações relatadas foram sem significância estatística dentro do mesmo grupo ou entre os dois grupos em intervalos de tempo diferentes. Conclusão: Ambas as modalidades de tratamento; overdentures sobre implantes telescópicos e próteses híbridas fixas parafusadas são confiáveis para reabilitar as arcadas completamente edêntulas. A decisão de fazer uma prótese fixa ou removível sobre implantes deve ser guiada pela preferência do paciente juntamente com a avaliação do dentista em relação ao estado geral do paciente e sua saúde bucal. (AU)

Bone density and implant stability with advanced platelet-rich fibrin in immediately loaded- implant assisted mandibular overdentures / Densidade óssea e estabilidade dos implantes com fibrina rica em plaquetas avançada em overdentures mandibulares com carga imediata

ABSTRACT Objective: The aim of this study is to determine the effect of Advanced Platelet-Rich Fibrin on bone density and implant stability in immediately loaded- implant-assisted mandibular overdentures (Split-mouth study). Material and Methods: Ten completely edentulous patients received two implants in the mandibular canine region and locator attachments were used to retain immediately loaded- implant mandibular overdentures. Each patient served in two Groups, one Group for each side. One side of the mandible received an implant with topical application of Advanced Platelet-Rich Fibrin in the implant osteotomy site (Group I) and the other site received an implant without application of Advanced platelet-rich fibrin (Group II). Each patient was examined clinically for implant stability using Osstell Mentor device and radiographically by ultra-low dose CT scan to measure bone density around the implant at baseline, three, six months, and one year. Results: There were no statistically significant differences (P>.05) in bone density and implant stability among the studied Groups during one year follow-up period. Conclusion : Advanced Platelet-Rich Fibrin has no effect on bone density and implant stability in immediately loaded implant-assisted mandibular overdenture.(AU)

RESUMO Objetivo: O objetivo deste estudo é determinar o efeito da Fibrina Rica em Plaquetas Avançada na densidade óssea e estabilidade dos implantes em Overdentures mandibulares com carga imediata (estudo de boca dividida). Material e Métodos: Dez pacientes edêntulos foram submetidos à instalação de dois implantes mandibulares na região dos caninos e pilares locator foram utilizados como sistema de retenção para as overdentures mandibulares com carga imediata. Cada paciente participou nos dois grupos, sendo um grupo para cada lado. Um lado da mandíbula recebeu implante com aplicação tópica de Fibrina Rica em Plaquetas Avançada no local do sítio cirúrgico do implante (Grupo I) e o outro local recebeu implante sem aplicação de Fibrina Rica em Plaquetas Avançada (Grupo II). Cada paciente foi examinado clinicamente quanto à estabilidade do implante usando o dispositivo Osstell Mentor e radiograficamente por tomografia computadorizada de ultrabaixa dose para medir a densidade óssea ao redor do implante no início do estudo, três, seis meses e um ano. Resultados: Não houve diferenças estatisticamente significativas (P>0,05) na densidade óssea e na estabilidade do implante entre os grupos estudados durante o período de acompanhamento de um ano. Conclusão: A Fibrina Rica em Plaquetas Avançada não tem efeito na densidade óssea e na estabilidade de implantes em Overdentures mandibulares com carga imediata (AU)

Preparation of ICD and overdenture in patients with Cushing's Syndrome: five-year follow-up / Preparo de PTI e overdenture em pacientes com Síndrome de Cushing: cinco anos de acompanhamento

The aim of this study is to report a clinical case of a patient with Cushing's syndrome, low self-esteem and need for oral rehabilitation. A 50-year-old female patient with hypercortisolism sought care at School of Dentistry of the Federal University of Minas Gerais. During anamnesis, the patient reported painful symptoms and mobility of the upper and lower teeth. On clinical examination, absence of many teeth were observed, periodontal disease and caries lesions. After discussion of the case, the planning involved the extraction of all teeth, and the preparation of Maxillary Immediate Complete Dentures (ICD's) and Immediate Mandibular Implant-retained Overdenture (IMIO). The treatment proposed allowed the restored aesthetics, phonetics and chewing(AU)

O objetivo desse estudo é relatar um caso clínico de uma paciente com síndrome de Cushing, baixa autoestima e necessidade de reabilitação oral. Paciente do sexo feminino, 50 anos de idade e com hipercortisolismo, procurou atendimento na Faculdade de Odontologia da Universidade Federal de Minas Gerais. Durante a anamnese, a paciente relatou sintomas dolorosos e mobilidade dos dentes superiores e inferiores. No exame clínico, foi observada a ausência de muitos dentes, doença periodontal e lesões cariosas. Após a discussão do caso, o planejamento envolveu a extração de todos os dentes, e o preparo de Prótese Total Imediata maxilar (PTI), e Overdenture Implantorretida Imediata mandibular. O tratamento proposto permitiu que restaurasse a estética, fonética e mastigação(AU)

Tratamiento protésico con sobredentadura en un anciano / Prosthetic treatment with overdenture in an elderly

Se describe el caso clínico de un anciano de 63 años de edad, con color de la piel mestizo y buena salud general, quien acudió a consulta de Prótesis Dental en la Clínica Estomatológica Provincial Docente Mártires del Moncada de Santiago de Cuba porque se encontraba afectado estéticamente y, además, deseaba preservar sus dientes remanentes; refirió que no había recibido tratamiento protésico previo. Luego de efectuar exámenes bucodental y complementarios, así como otros procedimientos odontológicos, se decidió rehabilitar con sobredentadura para conservar los dientes pilares, restablecer las funciones perdidas y mejorar la estética. El paciente fue rehabilitado estética y funcionalmente y mostró una evolución satisfactoria.

The case report of a half blood 63 years elderly with good general health, who visited the Dental Prosthesis Service in the Mártires del Moncada Teaching Provincial Estomatological Clinic in Santiago de Cuba is described, as he was esthetically affected and, he wished to preserve his remanent teeth; he informed that he had not received any previous prosthetic treatment. After making oral and dental exploration and other exams, as well as other odontological procedures, it was decided to rehabilitate him with overdentures to preserve the abutment teeth, to reestablish the lost functions and to improve esthetics. The patient was rehabilitated esthetically and functionally and he showed a satisfactory clinical course.

Prótese overdenture: sistema o'ring / Overdenture prosthesis: o'ring system

Overdenture é uma prótese total que se caracteriza por usar apoios retentivos para que aumente sua estabilidade e retenção na cavidade bucal, gerando assim menor desconforto ao paciente e melhor adaptação. A Prótese overdenture dentossuportada necessita de elementos dentais remanescentes com canais tratados endodonticamente e que possuam suporte periodontal adequado. O objetivo deste relato de caso clínico é expor a sequência de confecção de uma prótese overdenture dentossuportada maxilar associada a uma prótese total convencional mandibular, com os passos clínicos detalhados por meio de uma abordagem teórica e visual. Esse tipo de reabilitação favorece a adaptação do paciente à nova condição, visto que o uso de próteses totais convencionais pode causar certo desconforto ao paciente devido à falta de retenção e estabilidade. Essa manutenção dos dentes remanescentes favorece à manutenção óssea e a futura decisão do paciente em optar pela instalação de implantes dentários, podendo confeccionar próteses implantorretidas (overdentures) ou implantossuportadas (protocolo).O Paciente demonstrou-se satisfeito com o resultado estético e funcional após a instalação da prótese concretizando que o tratamento é viável(AU)

Overdenture is a denture that utilizing retentive supports for increase stability and retention in oral cavity. The tooth-supported overdenture require dental elements with root canal therapy and good periodontal support. The aim of this study is to report the confection of a maxillary tooth-supported overdenture associated with mandibular denture and your clinical steps. This rehabilitation promotes the patient's adaptation the new condition, since the use of conventional dentures may cause discomfort due to lack of retention and stability. The preservation of dental elements promotes bone maintenance and forthcoming decision of the patient in the installation of dental implants that can choose implantretained or implant-supported prosthesis. Patient was satisfied with aesthetic and functional result after installation of prosthesis(AU)

Qualitative evaluation of immediate rehabilitation: a case report with 5 years of follow-up / Avaliação qualitativa de reabilitação imediata: relato de caso com 5 anos de acompanhamento

Próteses totais imediatas e overdentures mandibulares em carga imediata, são boas alternativas para restaurar a função e a estética. Além disso, proporcionam um fator psicológico positivo, eliminando as consequências emocionais e sociais da perda dos dentes. O objetivo deste estudo foi relatar um caso clínico, com cinco anos de acompanhamento, utilizando parâmetros clínicos e ferramentas qualitativas, para analisar o impacto na qualidade de vida do paciente e no sucesso do tratamento. Este caso clínico foi desenvolvido em um projeto assistencial da Faculdade de Odontologia da Universidade Federal de Minas Gerais, Brasil, que promove a reabilitação oral de pacientes de baixa renda com dentes severamente comprometidos. Paciente do sexo masculino, 57 anos, apresentou-se para tratamento com condição severa de saúde dental e periodontal. O plano de tratamento proposto foi a extração dos dentes remanescentes e confecção de prótese total imediata maxilar e overdenture mandibular, em carga imediata, sobre implantes. O paciente foi acompanhado periodicamente, a cada seis meses, para substituição do o´rings, conforme recomendação do fabricante. Após 5 anos, as próteses foram reembasadas com resina acrílica termopolimerizável e os componentes protéticos da overdenture foram substituídos. Em um acompanhamento qualitativo, a equipe utilizou uma entrevista narrativa, com foco nos impactos do tratamento na qualidade de vida desse paciente. Ele confirmou, em um relato em primeira pessoa, sua satisfação com o tratamento realizado e a melhora nas relações sociais, afetivas e no trabalho, mostrando como a reconquista do sorriso pode transformar a experiência pessoal do indivíduo(AU)

Immediate complete dentures and mandibular immediately loaded overdentures are good alternatives to restore function and aesthetics. Moreover, they provide positive psychological factor, eliminating the emotional and social consequences of tooth loss. The aim of this study was to report a clinical case, with five years of follow-up using clinical parameters and qualitative tools, to analyze the impact on quality of life and the success of treatment. This clinical case was developed in an assistance project of the Dental School of Federal University of Minas Gerais in Brazil, which promotes oral rehabilitation of low-income patients with severely damaged dentitions. A 57-yearold male patient presented for treatment with a severe dental and periodontal health condition. The proposed treatment plan was extraction of the remaining teeth and making maxillary immediate complete denture and mandibular immediately loaded implant-supported overdenture. The patient was monitored periodically, every six months, to replace the polymer ring ball attachment, according to the manufacturer's recommendation. After 5 years, the prostheses were relining with heat-polymerized acrylic resin and overdenture prosthetic components were replaced. In a qualitative follow-up, the team used a narrative interview, focusing on the impacts of treatment in the quality of life of this patient. He confirms, in a firstperson account, his satisfaction with the treatment performed and improvements in social and affective relations and in the work, showing how the reconquest of the smile can transform the personal experience of the individual(AU)

Does the Use of Surface Electromyography Could Improve Quality of Life among Patients Rehabilitated by Mandibular Overdentures on Different Attachments?

Abstract Objective: To analyze and compare changes of quality of life parameter among dental patients rehabilitated by the implant-supported overdentures with different attachment systems. Material and Methods: Forty-eight patients were recruited as a study cohort. The implant placement procedure was based on the results obtained by CBCT scanning and individualized surgical templates manufactured for correct implant placement. Each individual received two k3Pro Implants (Sure Type with 4.0 or 4.5 mm in diameter) at the intraforaminal area due to standard protocol of implantation provided by the manufacturer under local anesthesia. All patients were distributed between two groups based on the fact of using either Locator- or ball-attachments. Rank correlation was measured using Spearman correlation coefficient, while linear correlation was evaluated by Pearson correlation coefficient. Results: No statistically meaningful differences were noted regarding patients' distribution among groups considering age (p>0.05) and gender (p>0.05). Provided patient-level analysis demonstrated that increase of conventional full denture service time was positively correlated with escalation of OHIP-EDENT scores. The most prominent inter-correspondences were noted specifically between longevity of denture service and elevation of scores within "Functional limitation" (r=0.61; p<0.05), "Physical pain" (r=0.51; p<0.05) and "Physical disability" (r=0.57; p<0.05) subdomains. No statistically argumented regressions were noted between increase tendency of OHIP-EDENT scores and gender (p>0.05) or age (p>0.05) parameters. Conclusion: Significant improvements of quality of life measured with OHIP-EDENT were noted for both types of attachments compared to the pre-treatment situation independently of additionally provided surface electromyography-based alignment.

The effect of attachment types and implant level on the stress distribution in a mandibular overdenture: a 3D Finite Element Analysis / O efeito dos tipos de sistemas de retenção e nível dos implantes na distribuição de tensões em overdentures mandibulares: Análise por Elementos Finitos 3D

Objective: The objective of this study was to evaluate the stress distribution in bone-surrounding implants placed in different levels in a mandibular overdenture. Material and Methods: A Computerized Tomography (CT) scan of an edentulous mandible was used to generate the models. Two implants with an internal connection were placed perpendicular to the occlusal plane in the Canine sites of the mandible. The implant in the left side was placed 1mm higher than the other side. Dolder bar and ball attachments were designed. Loading was performed by clenching the teeth with reconstruction of the muscles. In the anterior loading condition, force was applied to the central incisors and in the posterior loading conditions, it was applied to the molars and premolars. Then the Maximum Principal Stresses in the peri implant bone was evaluated with finite element analysis. Results:In both models, the highest stress values were recorded in the cortical bone surrounding the higher implant except in the ball model with unilateral load application on the right side (64.7 MPa). In almost all loading conditions the stress value differences in models with bar and ball attachments were low. Only in the anterior loading condition, the stress magnitude was higher in two implants of the ball model (60.5 MPa in the left side and 21 MPa in the right side) compared to the bar model (54.5 MPa in the left side and 17.5 MPa in the right side). Conclusion: The stress concentration did not affected considerably by the attachment system. High stress values were found adjacent the implant with a higher level. To reduce the amount of stress, bilateral balance occlusion should be considered. (AU)

Objetivo: O objetivo deste estudo foi avaliar a distribuição de tensões em tecido ósseo ao redor de implantes instalados em diferentes níveis em uma Overdenture mandibular. Material e Métodos: Uma tomografia computadorizada (TC) de uma mandíbula edêntula foi usada para gerar os modelos. Dois implantes de conexão interna foram instalados perpendicularmente ao plano oclusal na região de caninos inferiores. O implante do lado esquerdo foi instalado 1mm acima do que do lado direito. A barra Dolder e o pilar tipo bola foram projetados. A carga foi realizada apertando os dentes com reconstrução dos músculos. Na condição de carga anterior, a força foi aplicada nos incisivos centrais e nas condições de carga posterior, foi aplicada nos molares e pré-molares. Em seguida, as Tensões Máximas Principais no osso periimplantar foram avaliadas com análise de elementos finitos. Resultados: Em ambos os modelos, os maiores valores de tensão foram registrados ao redor do osso cortical ao redor do implante superior, exceto no modelo tipo bola com aplicação de carga unilateral no lado direito (64,7 MPa). Em quase todas as condições de carregamento, as diferenças nos valores de tensão nos modelos com fixações de barra e tipo bola foram baixas. Apenas na condição de carregamento anterior, a magnitude da tensão foi maior em dois implantes do modelo tipo bola (60,5 MPa no lado esquerdo e 21 MPa no lado direito) em relação ao modelo barra (54,5 MPa no lado esquerdo e 17,5 MPa no lado direito). Conclusão:A concentração de tensão não foi afetada considerando o sistema de retenção. Maiores valores de tensão foram encontrados adjacentes ao implante com um nível mais alto. Para reduzir a quantidade de tensão, a oclusão bilateral balanceada deve ser considerada.(AU)

Overdentures as an alternative to conventional dentures: a micro-costing analysis for Public Health Service in Brazil / Overdentures como alternativa às próteses convencionais: uma análise de micro-custeio para o Sistema Único de Saúde

Abstract This study aimed to estimate cost and compatibility with public financial incentives of two technologies for treating the edentulous mandible: lower complete dentures (CD) and overdentures retained by two dental implants (OD). This study consisted of a partial economic evaluation, with a micro-costing bottom-up approach for the calculation of direct costs. The estimates involved the number of consultations, proportion of materials, equipment, instruments' lifetime, and human resources, described in the price panel website of the Ministry of Economy in Brazil. Complementary information was obtained from a panel of experts. A sensitivity analysis was based on 20% variation. The estimated cost of a CD was R$ 189.89 (base scenario), and this varied between R$ 151.91 and R$ 227.89 according to sensibility analysis. The cost of an OD was R$ 663.05 (ranging from R$ 795.66 to R$ 530.44 - 1US=R$ 3.80/July 2019). The Ministry of Health covers appropriately the costs of the CD and OD. Both technologies showed costs that are within the limits of financial public incentives obtained by municipalities. The technologies are economically viable and should be induced through public policies due to their positive impacts on several functional domains of health.

Resumo Estimar os custos e a compatibilidade dos incentivos públicos de duas tecnologias para o tratamento da mandíbula edêntula: prótese total convencional (PTC) e overdenture retida por dois implantes (OD). Este estudo consistiu em uma avaliação econômica parcial, com abordagem "bottom-up" para o cálculo dos custos diretos. As estimativas levaram em consideração o número de consultas, proporção de materiais, equipamentos, vida útil dos instrumentais e recursos humanos. Os custos foram baseados no painel de preços do Ministério da Economia do Brasil e informações complementares foram obtidas de um painel de especialistas. Uma análise de sensibilidade foi baseada na variação de 20% dos custos. Os custos da PTC foram estimados em R$ 189,89 (cenário base) com variação entre R$ 151,91 e R$ 227,89 na análise de sensibilidade. Os custos da OD foram R$ 663,05 (variando de R$ 795,66 a R$ 530,44). O Ministério da Saúde cobre apropriadamente os custos de ambas as tecnologias nos cenários base e mais otimista. Ambas as tecnologias apresentaram custos dentro dos limites dos incentivos públicos recebidos. As tecnologias são economicamente viáveis e devem ser induzidas por políticas públicas diante do impacto positivo em vários domínios funcionais da saúde.

Análisis retrospectivo de implantes para sobredentaduras en maxilar inferior, en el marco de la formación de recursos humanos / Retrospective analysis of dental implants placed in the lower jaw, within the post graduate dental training framework

Objetivo: Evaluar el porcentaje de implantes oseointegrados colocados en pacientes edéntulos para la confección de sobredentaduras inferiores, en el marco de la formación de recursos humanos. Materiales y métodos: Se analizaron las historias clínicas de los pacientes que recibieron dos implantes dentales inferiores para la confección de sobredentaduras en el servicio de residentes de la carrera de Especialización en Cirugía y Traumatología Bucomaxilofacial de la Facultad de Odontología de la Universidad de Buenos Aires, entre agosto de 2012 y diciembre de 2018. Se consideraron para el análisis el porcentaje de implantes oseointegrados y su relación con el tipo de operador (docente o residente), la situación del reborde óseo y el hábito de fumar. Resultados: De los 176 implantes colocados en 88 pacientes (edad promedio = 67 años), a los 3-4 meses el 98% (IC95: 94-99%) se hallaba oseointegrado. No se encontró una relación estadísticamente significativa entre el tipo de operador y el fracaso (P>0,99) Conclusión: En un servicio de formación, la tasa de éxito, evaluada en la segunda cirugía, de dos implantes dentales colocados en el maxilar inferior para sobredentaduras fue de 98%. No se hallaron diferencias entre los resultados logrados por residentes y docentes del servicio (AU)

Aim: To evaluate the percentage of osseointegrated im- plants placed in edentulous patients to restore with mandib- ular overdentures, within the post graduate dental training framework. Materials and methods: Medical records of patients who received two dental implants in the mandible for the placement of overdentures in the resident clinic of the special- ization career in Oral and Maxillofacial Surgery and Trauma- tology from the Facultad de Odontología de la Universidad de Buenos Aires, between August 2012 and December 2018. The percentage of osseointegrated implants was analysed, and the association with the variables: operator (teacher or resident), mediate or immediate placement, and smoking. Results: 176 implants were placed in 88 patients with an average age of 67 years old. 98% (IC95: 94-99%) of the implants were osseointegrated at 3-4 months. No statistically significant association was detected between the type of oper- ator and implant failure (P>0.99). Conclusion: In the teaching dental training clinic, the success rate, evaluated at the second implant stage surgery, of two dental implants placed in the mandibule for overden- tures was 98%. No differences were found between the results achieved by residents and teachers (AU)

Effect of cleanser solutions on the retention force of oring attachment: an in vitro study

Abstract The aim of this study was to evaluate the effect of cleaning solutions on the retention force of o-ring-type overdenture attachments. The effect of four solutions on nitrile rings were evaluated: Cepacol (C), Cepacol with fluoride (CF), Listerine (L) and 0.05% sodium hypochlorite (SH); deionized water (DW) was used as a control. Matrices containing two implants and abutments and acrylic specimens with the metal capsules were obtained and divided into the groups. A simulation of 90 overnight immersions (8 h) was performed, and the tensile strength value was obtained at the beginning (T0) and in every 30 days (T1, T2 and T3) (n=6). In order to analyze o-ring surface damage after the immersions, a scanning electron microscopy (SEM) was used (n=1). For statistical analysis of the results, analysis of variance (ANOVA) and multiple comparisons with Bonferroni adjustment (test power=1.000; a=0.05) were used. There was a significant difference for the factors time (p<0.001), solution (p<0.001) and for the interaction time × solution (p<0.001). Considering the times of each solution, only for DW there was no significant loss of retention over time. Comparing the solutions in each moment, there was no difference among the solutions in T0. From T1, CF and SH provided less retention than DW (p<0.005). Through SEM it was possible to observe changes in the surface of the CF and SH nitrile o-rings. CF and SH should be avoided due to deleterious action in o-rings.

Resumo O objetivo do estudo foi avaliar o efeito de soluções higienizadoras sobre a força de retenção de encaixes do tipo o-ring. Foram avaliadas quatro soluções: Cepacol (C); Cepacol com flúor (CF), Listerine (L), hipoclorito de sódio 0,05% (HS) e água deionizada (controle/AD) em o-rings de nitrilo. Matrizes contendo dois implantes e pilares e espécimes em acrílico com as cápsulas metálicas foram obtidas e divididas entre os grupos. Foi realizada a simulação de 90 imersões noturnas (8 h), sendo obtido o valor da resistência à tração no início e a cada 30 dias (T0, T1, T2 e T3) por meio da máquina de ensaios mecânicos (n=6). Microscopia eletrônica de varredura (MEV) foi utilizada para análise de danos na superfície do o´ring após a imersão (n=1). Para análise estatística dos resultados foi utilizada análise de variância (ANOVA) e múltiplas comparações com ajuste de Bonferroni (poder do teste=1,000; a=0,05). Houve diferença significante para os fatores tempo (p<0,001), solução (p<0,001) e para interação de tempo × solução (p<0,001). Considerando-se os tempos de cada solução, apenas AD não apresentou perda significativa de retenção ao longo do tempo. Comparando as soluções em cada momento, não houve diferença entre as soluções em T0. A partir de T1, CF e HS propiciaram menor retenção quando comparados à AD (p <0,005). Através do MEV foi possível observar alterações nas superfícies dos o-rings de nitrilo imersos em CF e HS. O Cepacol com flúor e hipoclorito de sódio devem ser evitados devido à ação deletéria nos o-rings.

Observation of the effect on immediate mandibular implant-supported overdenture of micro implant system of Italy / Observação do efeito na sobredentadura imediata mandibular suportada por implante do sistema de micro implante da Itália

The study was design to investigate the clinical effect of Micro implant system in Italy on immediate mandibular implant-supported overdenture. A total of 192 patients with mandibular edentulous treated in our hospital were randomly divided into 2 groups in which the control group consisted of 96 patients treated with immediate mandibular implant-supported overdenture by Xive implant system, while the observation group included 96 cases treated with the overdenture by Italy Micro implant system. Patients were followed up for 1 year and then the states of implant-borne overdentures, marginal bone resorption around alveolar bone, the compatibility of implant restorations with adjacent teeth, adverse events and satisfaction degree were compared between the groups. According to the results of 1-year follow-up, the resorption around alveolar bone of the observation group was significantly higher than that of the control group (p<0.05). In the observation group the differences in labial gingival margin position, gingival color and texture were significantly better (p<0.05) as compared to control group. The incidence of adverse events was notably lower (p<0.05). The Italy Micro implant system has significant curative effect on mandibular implant-supported overdentures with good compatibility of the implant restorations with adjacent teeth and low incidence rate of adverse reactions, so it is worthy of clinical application and spreading.

O estudo foi desenvolvido para investigar o efeito clínico do sistema de implantes de B&B na Itália na prótese total imediata apoiada em implante mandibular. Um total de 192 pacientes com desdentação mandibular, tratados em nosso hospital foram divididos aleatoriamente em 2 grupos, nos quais o grupo controle consistia em 96 pacientes tratados com overdenture imediato apoiado por implante mandibular pelo sistema de implante Xive, enquanto o grupo de observação incluiu 96 casos tratados com o sobredentadura pelo sistema de implantes Itália B&B. Os pacientes foram acompanhados por 1 ano e, em seguida, foram comparados os estados de sobredentaduras implanto-suportadas, reabsorção óssea marginal ao redor do osso alveolar, compatibilidade das restaurações do implante com dentes adjacentes, eventos adversos e grau de satisfação. De acordo com os resultados do seguimento de 1 ano, a reabsorção ao redor do osso alveolar do grupo de observação foi significativamente maior que a do grupo controle (p <0,05). No grupo de observação, as diferenças na posição da margem gengival labial, cor gengival e textura foram significativamente melhores (p <0,05) em comparação ao grupo controle. A incidência de eventos adversos foi notavelmente menor (p <0,05). O sistema de implantes B&B da Itália tem um efeito curativo significativo nas sobredentaduras mandibulares suportadas por implantes, com boa compatibilidade das restaurações dos implantes com dentes adjacentes e baixa taxa de incidência de reações adversas, por isso é digno de aplicação clínica e disseminação.

Evaluation of bite force and masticatory performance: complete denture vs mandibular overdenture users

Abstract: This cross-sectional observational study with 24 patients evaluated differences in bite force (BF) and masticatory performance (MP) between conventional complete denture (CCD) and implant mandibular overdenture (IMO) users and the correlation between these variables. The BF test was performed bilaterally with an occlusal force device. During the MP test, patients were asked to chew Optocal particles for 40 cycles. The Shapiro Wilk test was employed to verify the normality of the data, the student t test to identify differences between groups, and Pearson's correlation to investigate interrelationships between variables. A multiple linear regression was subsequently performed via the stepwise method. P values ≤0.05 were considered statistically significant. Unlike IMO users, CCD users presented a significant difference (25.6%) in BF between the dominant and non-dominant chewing side (p=0.04). IMO users presented significantly higher BF (p=0.01) without presenting a dominant side (p=0.38), and also performed significantly better for the following MP parameters: MPX50 values decreased by 27.25% in IMO users (p=0.01), MPB decreased by 48.38% (p=0.01), and ME 5.6 decreased by 53.25% (p=0.02), while ME2.8 increased by 151.57% (p=0.01). The BF and MPX50 in the IMO wearers group were negatively correlated (-0.57; p=0.05); this correlation coefficient was the only parameter included in the multivariate regression model. IMO users have higher BF and better masticatory performance than CCD users, especially in terms of chewed particles size reduction. MP is correlated with a higher BF in IMO users through better particle trituration.

Resumo Este estudo observacional transversal com 24 participantes teve como objetivo avaliar as diferenças na força de mordida (FM) e na PM (performance mastigatória) entre usuários de prótese total convencional (PTC) e de overdenture mandibular (OM) e a correlação entre essas variáveis. O teste de FM foi realizado bilateralmente com um dispositivo de força oclusal. Durante o teste de PM, os pacientes foram solicitados a mastigar uma porção padronizada de Optocal por 40 ciclos mastigatórios. O teste de Shapiro Wilk foi empregado para verificar a normalidade dos dados, o teste T de Student para identificar diferenças entre os grupos e os coeficientes de correlação de Pearson para investigar inter-relações entre variáveis. Uma regressão linear múltipla foi realizada pelo método stepwise. Valores de p≤0,05 foram considerados estatisticamente significantes. Diferentemente dos usuários de OM, os usuários de PTC apresentaram uma diferença significativa (34%) na FM entre o lado dominante e o não dominante (p=0,04). Os usuários de OM apresentaram FM significativamente maior (p=0,01) sem apresentar um lado dominante (p=0,38) e obtiveram PM significativamente melhor nos seguintes parâmetros: os valores de PMX50 diminuíram 27,25% (p=0,01), PMB diminuiu em 48,38% (p=0,01), e EM 5.6 diminuiu 53,25% (p=0,02), enquanto EM2.8 aumentou 151,57% (p=0,01). A FM e PMX50 no grupo de usuários da IMO foram negativamente correlacionados (-0,57;p=0,05); esse coeficiente de correlação foi o único parâmetro incluído no modelo de regressão multivariada. Os usuários da OM possuem maior FM e melhor performance mastigatória do que os usuários de PTC, observados principalmente na redução do tamanho das partículas mastigadas. A PM está correlacionada com um maior FM nos usuários da OM através de uma melhor trituração de partículas.

Overdenture on dental remaining in oncological patients: case report / Overdenture sobre remanescente dental em paciente oncológico: relato de caso

Head and neck cancer occupy the seventh place among the most common neoplasms in the world, with an annual incidence of approximately 640,000 new cases. Radiotherapy treatment has been highlighted, because there is greater tissue preservation, possibility of regression of the disease, decreased tumor volume, prevention of possible tumor recurrences and metastases, and even total cancer cure, but patients undergoing radiotherapy are at high risk of osteoradionecrosis if they perform surgical interventions in the region, such as dental implants and dental extraction, making prosthetic rehabilitation of partially edentulous patients after treating oral cancer something complex and often omitted; although it is a crucial factor in restoring oral function. Thus, the aim of the present study was to describe the planning, treatment and follow-up of a twelve-month prosthetic approach to rehabilitate the lower arch shape and function of a partially edentulous patient undergoing head and neck radiotherapy with a full denture mucus supported and tooth retained. After twelve months of follow-up, it was possible to evidence the functional and aesthetic clinical success, with preserved occlusal pattern, soft and bone tissue around and dental roots. (AU)

O câncer de cabeça e pescoço ocupa o sétimo lugar entre as neoplasias mais comuns do mundo, com uma incidência anual de aproximadamente 640.000 novos casos. O tratamento com radioterapia tem se destacado, pois há maior preservação tecidual, possibilidade de regressão da doença, diminuição do volume tumoral, prevenção de possíveis recorrências e metástases tumorais e até cura total do câncer, mas os pacientes submetidos à radioterapia apresentam alto risco de osteorradionecrose se realizar intervenções cirúrgicas na região, como implantes dentários e extração dentária, fazendo com que a reabilitação protética, de pacientes parcialmente dentados depois de tratar o câncer bucal, algo complexo e frequentemente omitido; embora seja um fator crucial para o reestabelecimento da função oral. Assim, o objetivo do presente estudo foi descrever o planejamento, tratamento e acompanhamento de doze meses de uma abordagem protética para reabilitar forma e função do arco inferior de um paciente parcialmente desdentado, submetido a radioterapia de cabeça e pescoço, com o uso de uma prótese total mucossuportada e dente retida. Após doze meses de acompanhamento, foi possível evidenciar o sucesso clínico funcional e estético, com padrão oclusal, rebordo alveolar e remanescentes dentários preservados (AU)

Effects of type of magnet attachment and implant angulation in two implant overdenture models

PURPOSE: The purpose of this study is to evaluate the effects of type of magnet attachment and implant angulation in two implant overdenture models.MATERIALS AND METHODS: Magnet attachments used in this study were flat and dome types (MGT5515, MGT5520D, Dentium Co., Seoul, Korea). Two implants with keepers were inserted in the resin blocks at a distance of 24 mm. For the first model, the implants were parallel to the vertical and perpendicular to the horizontal; for the second model, both were angulated 5 degrees to the mesial; for the third model, both were angulated 10 degrees toward the mesial. The retentive force was measured in both vertical and lateral directions. Statistical analyses were performed using SPSS software version 22.0 (α=.05).RESULTS: The flat type magnet attachment showed the highest lateral retentive force in the 20° divergent group (P<.05) and the dome type magnet attachment showed the highest lateral retentive force in the parallel group (P<.05). The vertical and lateral retentive force of the dome type magnet attachment was greater than that of the flat type magnet attachment in every direction (P<.05).CONCLUSION: Within the limitations of this study, the dome shape magnet attachment can resist vertical and lateral retentive force more superiorly than the flat type magnet attachment, regardless of angle, in the mandibular two implant model.

Implant-assisted removable partial denture using freely removable abutment in a fully edentulous patient: A case report / 대한치과보철학회지

Implant-Assisted Removable Partial Dentures (IARPDs) treatment is being performed in a fully edentulous patient using implant surveyed prosthesis as an abutment. Implant-supported prosthesis as an abutment of IARPDs is classified into screw-retained and cement-retained type according to the retention type, and each has advantages and disadvantages. The EZ crown system (Samwon DMP, Yangsan, Korea) has a cylinder combined with abutment, and the nickel-titanium spring in this cylinder provides a constant force on the zirconia ball to obtain retention in EZ crown system. In this patient, the natural abutment teeth of the mandibular overdenture was hopeless. We planned implant assisted removable partial denture using anterior implant surveyed prosthesis considering functional and esthetical rehabilitation, cost and patient's needs. When fabricating IARPDs using implant as abutment, we could compensate for the shortcomings of existing implant-supported prosthesis retention type and made the design of removable partial denture easy due to using EZ crown system.

Evaluation of the effect of coating vertex denture lining material with plant oils on microbial growth and hardness

Aims: To evaluate the effect of surface coating with natural plant oils (Salvia officinalis, ginger and eucalyptus) on Candida growth and the hardness of Vertex denture lining material. Materials and method: Forty five specimens were prepared from soft acrylic lining material, twenty five of which were 10x10x2mm in size for testing antifungal activity, and twenty samples were 20mm in diameter and 12mm in thickness, for testing shore A hardness after coating samples with three types of natural oils (Salvia officinalis, ginger and eucalyptus oils). Significant differences among the groups at (p≤0.05) level of significance were determined statistically with one way analysis of variance and Duncan's multiple range test Result: Antifungal assay showed a significant difference between five groups regarding Candida albicans growth (p≤ 0.05). For the hardness test, comparing different times of storage in water (1, 7, 14, 30 days) revealed a significant difference within all groups (p≤0. 05). While comparing the groups coated with natural oils with the control group, significant differences were found between different times of storage in water (1, 7, 30 day) (p≤0.05), except at 14 days of water storage there was no significant difference between groups (p>0.05). Conclusion: All tested natural oils were effective as fungicidal agents and increased the softness and duration of soft acrylic lining material.

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.

Sensorial ability, mastication and nutrition of single-implant overdentures wearers

Abstract The use of two-implant overdentures improves mastication of edentulous elderly patients. However, little is known about the effects of single-implant overdentures (SIO) on oral perception and masticatory function in such elders. This study compared the effects of conventional complete dentures (CD) and SIO on the oral sensorimotor ability (OSA), masticatory function, and nutritional intake of elderly people with residual alveolar mandibular height classified as Class III or IV according to the American College of Prosthodontics. Twelve elders first received new conventional CD, which were later converted to SIO. All variables were evaluated after use of each prosthesis for 2 months. To evaluate OSA, elders closed their eyes and orally identified test pieces prepared from raw carrots. A kinesiographic device was used to measure chewing movements during mastication of a test material (Optocal). Masticatory performance (MP) was determined with the sieving method, and a 3-day food diary verified nutrient intake based on a standard Brazilian Food Composition Table. Data were analyzed using the Wilcoxon signed rank test and Student's paired t test (P < 0.05). OSA results did not differ according to prosthesis type. However, opening and closing velocities during chewing and MP increased after SIO insertion (P < 0.05). Although no difference was observed in the intake of most nutrients, sodium ingestion decreased after SIO insertion (P < 0.05). SIO use had no effect on OSA, but significantly improved mastication and sodium intake of elders with decreased residual ridges height (Brazilian Registry of Clinical Trials #RBR-3kgttj).

Resumo A utilização de overdentures suportadas por dois implantes melhora a mastigação de pacientes idosos edêntulos que apresentam rebordos residuais reabsorvidos. No entanto, pouco se sabe sobre os efeitos de overdentures suportadas por único implante central mandibular (SIO) em relação à percepção oral e função mastigatória em tais idosos. O atual estudo comparou os efeitos de próteses totais convencionais (CD) e SIO na capacidade de sensorimotora oral (OSA), função mastigatória e ingestão nutricional de idosos com altura de rebordos mandibulares tipo III e IV de acordo com a Colégio Americano de Prótese. Doze idosos receberam primeiramente novas CD convencionais, as quais, posteriormente, foram transformadas em SIO. Variáveis foram avaliadas após o uso de cada prótese durante 2 meses. Para avaliar OSA, os idosos fecharam os olhos e testaram oralmente a identificação de formatos geométricos confeccionados de cenouras cruas. Um dispositivo cinesiográfico foi utilizado para medir os movimentos durante a mastigação de material de teste (Optocal). A performance mastigatória (MP) foi determinada com o método de fracionamento de peneiras e um diário de alimentação aplicado por 3 dias consecutivos verificou a ingestão de nutrientes com base em uma Tabela Brasileira Padrão de Composição de Alimentos. Os dados foram analisados utilizando os testes Wilcoxon signed rank test e Student's paired t test (p<0,05). OSA resultados não diferiram de acordo com o tipo de prótese. No entanto, as velocidades de abertura e fechamento durante a mastigação e MP aumentaram após a inserção de SIO (p<0,05). Embora não tenha sido observada diferença na ingestão da maioria dos nutrientes, a ingestão de sódio diminuiu após a inserção de SIO (p<0,05). O uso de SIO não teve efeito sobre OSA, mas melhorou significativamente a mastigação e a ingestão de sódio de idosos com altura de rebordos residuais reduzidas (Registro Brasileiro de Ensaios Clínicos # RBR-3kgttj).

Biomechanical behavior of overdentures supported by different implant position and angulation using Micro ERA® system: a finite element analysis study

Aim: The aim of this study was to investigate the biomechanical behavior of implant-retained mandibular overdentures using Micro ERA® system with different implant position and angulation by finite element analysis (FEA). Methods: Four 3D finite element models of simplified mandibular overdentures were constructed, using one Bränemark implant with a Micro ERA® attachment. The implant was positioned on the canine or lateral incisor area with an angulation of either 0º (C-0º; LI-0º) or 17º (C-17º, LI-17º) to the vertical axis. A 100 N axial load was applied in one side simultaneously, from first premolar to second molar. In all models it was analyzed the overdenture displacement, compressive/tensile stress in the bone-implant interface, and also the von Mises equivalent stress for the nylon component of the housing. The stresses were obtained (numerically and color-coded) for further comparison among all the groups. Results: The displacement on the overdenture was higher at the posterior surface for all groups, especially in the C-17º group. When comparing the compressive/tensile stress in the bone-implant interface, the lateral-incisor groups (LI-0º and LI-17º) had the highest compressive and lowest tensile stress compared to the canine groups (C-0º and C-17º). The von Mises stress on the nylon component generated higher stress value for the LI-0º among all groups. Conclusions: The inclination and positioning of the implant in mandibular overdenture interferes directly in the stress distribution. The results showed that angulated implants had the highest displacement. While the implants placed in the lateral incisor position presented lower compressive and higher tensile stress respectively. For the attachment the canine groups had the lowest stress