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)

Finite element analyses of retention of removable partial denture circumferential clasps manufactured by selective laser melting / 北京大学学报(医学版)

OBJECTIVE@#To compare the retentions of different designs of cobalt-chromium (Co-Cr), pure titanium (CP Ti), and titanium alloy (Ti-6Al-4V) removable partial denture (RPD) circumferential clasps manufactured by selective laser melting (SLM) and to analyze the stress distribution of these clasps during the removal from abutment teeth.@*METHODS@#Clasps with clasp arm size A (1.9 mm width/1.1 mm thickness at the body and 0.8-taper) or B (1.2 times A) and 0.25 mm or 0.50 mm undercut engagement were modeled on a prepared first premolar die, named as designs A1, A2, A3, and A4, respectively. The density and elastic modulus of SLM-built Co-Cr, CP Ti, and Ti-6Al-4V were measured and given to different groups of clasps. The density, elastic modulus, and Poisson ' s ratio of enamel were given to the die. The control group was the cast Co-Cr clasp with design A1, to which the density and elastic modulus of cast Co-Cr alloy were given. The Poisson's ratio of all metals was 0.33. The initial 5 N dislodging force was applied, and the maximum displacement of the clasp along the insertion path was computed. The load was reapplied with an increment of 5 N than in the last simulation until the clasp was completely dislodged. The retentive force range of different groups of clasps was obtained. The retentive forces of the SLM-built Co-Cr, CP Ti, and Ti-6Al-4V clasps with equivalent computed retentive force range to the control group were validated through the insertion/removal experiment. The von Mises stress distributions of these three groups of SLM-built clasps under 15 N loads were analyzed.@*RESULTS@#SLM-built Co-Cr, CP Ti, and Ti-6Al-4V clasps with designs B1 or B2, and Co-Cr clasps with design A2 had higher retentive forces than those of the control group. SLM-built CP Ti and Ti-6Al-4V clasps with design A1 had lower retentive forces than those of the control group. SLM-built Co-Cr clasp with design A1 and SLM-built CP Ti and Ti-6Al-4V clasps with design A2 had equivalent retentive forces to those of the control group. The insertion/removal experiment showed that the measured retentive forces of these three groups of SLM-built clasps were (21.57±5.41) N, (19.75±4.47) N, and (19.32±2.04) N, respectively. No statistically significant measured retentive force difference was found among these three groups of SLM-built clasps (P>0.05). The maximum von Mises stress of these three groups of SLM-built clasps exceeded their responding yield strength except for the Ti-6Al-4V one.@*CONCLUSION@#SLM-built Co-Cr circumferential clasps had higher retention than CP Ti and Ti-6Al-4V ones with the same clasp arm size and undercut engagement. The retention of SLM-built circumferential clasps could be adjusted by changing the undercut engagement and clasp arm size. If SLM-built circumferential clasps are used in clinical practice, the Ti-6Al-4V clasp with clasp arm size A and 0.50 mm undercut engagement is recommended considering the long-term use of RPD in the patient's mouth.

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.

Comparison of the retention of conventional dentures after the use of common adhesive brands on poor denture foundations: an in vitro study / Comparación de la retención de dentaduras convencionales con el uso de marcas comerciales de adhesivos en procesos alveolares deficientes: un estudio in vitro

There is no information about the possible impact in denture retention after the use of common denture adhesives (DAs) when poor denture foundations (PDF) are present. Moreover, there is a lack of information about which current formulation provides greater retention and for how long. Twelve models from edentulous patients with different ridge shape and border height were used and complete dentures were manufactured. Four different formulation brands of DAs were tested after 10 minutes and three, six, nine, and 12 hours of DA application using a universal testing machine. The Fittydent® and Fixodent® adhesives had the highest retention at 12 hours. The PDF group increased on average its retention by 400 %. However, the group presented lower retention compared to the good denture foundation group. In conclusion, DAs significantly increased denture retention. The PDF group were the most benefited with the application of DAs. The Fixodent® paste had the highest retention.

No existe información acerca del posible impacto en la retención de dentaduras después del uso de adhesivos dentales comunes (DAs) cuando existen rebordes alveolares deficientes (PDF). Más aun, existe una falta de información acerca de cuál formula actual provee mayor retención y por cuanto tiempo. Doce modelos de pacientes edentulos con diferentes formas y alturas en sus rebordes alveolares fueron usados, y dentaduras completas les fueron realizadas. Cuatro diferentes fórmulas y marcas de DAs fueron evaluadas después de 10 minutos, tres, seis, nueve y 12 horas de que se aplicó el DA usando una maquina universal de pruebas. Los adhesivos Fittydent® y Fixodent® presentaron la retención más alta a las 12 horas. El grupo con PDF incrementó su retención hasta en un 400 %. Sin embargo, el grupo presentó menor retención cuando se comparó con el grupo que posee adecuados procesos alveolares. Los DAs incrementaron significativamente la retención de las dentaduras. El grupo PDF fue el más beneficiado con la aplicación de DAs. La pasta Fixodent® provee la más alta retención.

Retention strength of ball-attachment titanium post for removable partial denture or overdenture

Aim: To evaluate the retention of an endodontic titanium postwith a spherical head for removable partial denture or overdentureattachment according to surface treatment type. Methods: Sixtyhealthy single-rooted teeth, sectioned at the enamel/cementumjunction, were treated endodontically and steadily fixed in theembedding acrylic resin. The titanium posts were subdivided intofour groups: control, no surface treatment (Ctrl); posts with macroretentivegrooves (MR); air abrasion of the post surface (AB); andposts with macro-retentive grooves and air abrasion of the postsurface (MR+AB). The posts were luted in the root canal usingself-adhesive dual resin cement. Pull-out testing was performedusing a universal testing machine until complete detachment wasachieved. After pull-out testing, the metallic posts were examinedunder an optical microscope and the failures were classifiedbased on the cement distribution pattern on the extracted posts:0, no cement left on the post (cement/post failure); 1, postsurface partially covered by adhered cement (post/cement anddentin/cement mixed failure); 2, post surface completely coveredby cement (dentin/cement failure). The retention data wereanalyzed by one-way ANOVA, Bonferroni­Dunn test (p<0.05)and Weibull analysis. Results: AB showed the highest retentionvalue (485.37±68.36), followed by MR+AB (355.80±118.47), MR(224.63±42.54) and Ctrl (113.12 ± 51.32). AB and MR showedthe highest Weibull moduli. Conclusions: The data indicatedthat air abrasion alone could significantly increase the retentionof titanium posts/attachments for use with overdentures orremovable partial denture

Retención de molares primarios: diagnóstico, etiología, tratamiento y relato de caso clínico / Retenção de molares decíduos: diagnóstico, etiologia, tratamento e relato de caso clínico / Retention of primary molars: diagnosis, etiology, treatment and clinical case report

Este estudio presenta un relato de caso clínico sobre la retención de molares primarios, el objetivo es describir los medios de diagnóstico, la etiología, las implicaciones clínicas y el tratamiento de esta condición. Factores etiológicos locales, ambientales o genéticos pueden llevar a la retención de molares primarios, interfiriendo en la secuencia normal de erupción de los premolares. Paciente de sexo femenino, 12 años de edad, compareció a la clínica de Odontopediatría de la Facultad de Odontología de Araçatuba (FOA/UNESP), Brasil, con queja de dolor y aumento volumétrico en la región vestibular del diente 63 y cuadro casode erupción dentaria incompatible con la edad cronológica de los dientes 54/55, 75, 84/85. Exámenes complementarios fueron realizados para el establecimiento del diagnóstico, el cual se definió como retención prolongada de molares primarios. La conducta terapéutica fue basada en la realización de exodoncia de los dientes con retención prolongada, seguida del control clínico y radiográfico, hasta la erupción de los sucesores. Se concluye que el diagnóstico y la intervención temprana para la retención prolongada son de fundamental importancia para evitar daños a la oclusión.

Objetivo: Apresentar um relato de caso clínico sobre a retenção de molares de dentes decíduos, como o objetivo de descrever os meios de diagnóstico, a etiologia, as implicações clínicas e o tratamento desta condição. Fatores etiológicos locais, ambientais ou genéticos podem levar à retenção de molares decíduos, interferindo na sequência normal de erupção dos pré-molares. Paciente do sexo feminino, 12 anos de idade, compareceu à clínica de Odontopediatria da Faculdade de Odontologia de Araçatuba (FOA/UNESP), Brasil queixando-se de dor e aumento volumétrico na região vestibular do dente 63 e quadro de erupção dentária incompatível com a idade cronológica dos dentes 54/55, 65, 74/75, 84/85. Exames complementares foram realizados para o estabelecimento do diagnóstico, o qual foi definiu-se como retenção prolongada de molares decíduos. A conduta terapêutica baseou-se na realização de exodontia dos dentes com retenção prolongada, seguida do controle clínico e radiográfico, até a erupção dos sucessores. Conclui-se que o diagnóstico e a intervenção precoces para a retenção prolongada são de fundamental importância para evitar danos à oclusão.

This study shows a clinical case report about the retention of primary molars, with the aim of describing diagnosis, etiology, clinical implications and treatment of this condition. Local, environmental or genetic etiologic factors may lead to retention of primary molars, interfering with the normal sequence of eruption of the premolars. A 12-year-old female patient attended the Pediatric Dentistry Clinic of the Faculty of Dentistry of Araçatuba (FOA / UNESP), complaining of pain and volumetric increase in the buccal region of the tooth 63 and a scenario of age-incompatible eruption chronological analysis of teeth 54/55, 64/65, 74/75, 84/85. Complementary examinations were performed to establish the diagnosis, which was defined as prolonged retention of deciduous molars. Therapeutic conduct was based on the extraction of teeth with prolonged retention, followed by clinical and radiographic control until the successors erupted. It is concluded that the early diagnosis and intervention for prolonged retention are of fundamental Latinoamericanaimportance to avoid occlusal complications.

Evaluation of the clinical efficacy of implant-supported overdenture with edentulous mandible in elderly patients / 华西口腔医学杂志

The aging society of the global population has led to an increase in the number of patients with edentulous jaw, a common multiple disease. Given the developments in implant techniques, the method of implant denture has received a positive and good response in terms of the quality of life and psychological well-being of patients. Implant-supported overdenture in mandible has two main advantages. 1) It has better retention and chewing efficiency than those of mandibular conventional denture. The required implant site of implant-supported overdenture is less than that of fixed implant-supported denture and can repair more defect tissues to help restore beauty and pronunciation. The price of the former is more acceptable than that of the latter. Therefore, this article aimed to systemically analyze and further discuss the clinical effect of implant-supported overdenture in elderly patients; combine existing related studies on the selection of number, site, and upper restoration of implants; and illustrate the advantages of removable implant-supported protheses in the repair of toothless mandible.

Implant overdenture of mandible with severe unilateral atrophy: Report of two cases / 대한치과보철학회지

There are several unfavorable conditions regarding alveolar bone condition that may compromise the denture patient's satisfaction. Chewing efficiency may not be satisfactory when alveolar bone is deficient, and the denture stability could hardly be achieved when alveolar bone shape is irregular. Implant overdenture can be useful to provide satisfactory denture experience compared to conventional denture. The attachment for implant overdenture can be classified into bar attachment and solitary attachment. When the positions of the implants are in the mandibular anterior region, bar attachment may be favorable to obtain a rigid support of the entire denture. When implants are distributed both on anterior and posterior region, a solitary attachment could be considered for ease of removal and maintenance. This report presents implant overdenture cases with the patients that had unilateral mandibular alveolar bone atrophy conditions. Different abutments were chosen based on the individual patient's mandibular alveolar bone condition and the treatments were successful in terms of patient satisfaction.

Protocolo Clínico para Control de Prótesis Fija Total con Carga Inmediata / Clinical Protocol for Control of an Immediately Loaded Implant-Supported Prosthesis

RESUMEN: Los protocolos odontológicos de controles son guías que tienen por objetivo optimizar la calidad de atención y estandarizar ciertos procedimientos para poder establecer mejores pronósticos. Varias complicaciones se pueden presentar posterior a la instalación de una prótesis fija total con carga inmediata (PFTC), desde el daño de la estructura protésica provisoria hasta la pérdida de la oseointegración de los implantes dentales. La escasa evidencia sobre el comportamiento clínico que se debe tener posterior a este tipo de tratamiento indica la necesidad de confección de un protocolo para poder mejorar las tasas de éxito. Para confeccionar el protocolo clínico se realizó una revisión sistemática de la literatura en la base de datos PubMed. Los filtros de búsqueda fueron ajustados de la siguiente manera. Se utilizaron los términos de búsqueda "immediate loading" AND "full arch" AND "Resonance frequency analysis". Los que fueron sometidos a los criterios de inclusión y exclusión, dando como resultado un total de 15 estudios. Todos los estudios seleccionados son ensayos clínicos controlados donde se encontraron complicaciones como fracturas, desalojos y desgaste de la estructura protésica, entre otros. En los resultados encontrados no existe evidencia sobre el número y rango de sesiones necesarias para el control clínico de una PFTCI. El momento más indicado para la extracción de la prótesis provisoria e instalación de la prótesis definitiva es durante el 3° y 4° mes posterior a la carga inmediata. Existe escasa evidencia sobre el número, momento y tipo de examen imageneológico a solicitar. Por lo que este protocolo clínico será una guía para los controles que se realicen posterior a una instalación de una PFTCI.

ABSTRACT: Dental protocols are guidelines used to optimize service quality and to standardize procedures to establish a better prognosis. There are many complications that can occur after installation of a an immediately loaded implant-supported prosthesis for rehabilitation. These may generate damage to the provisional structure and even loss of osseointegration from the dental implants. Limited evidence on the clinical approach required to monitor these procedures, makes it necessary to establish clinical protocols for treatment control, and increases the success rate. In order to develop such protocols a systematic research was carried out in the Pubmed database. The filters used were "immediate loading", "full arch" and "Resonance frequency analysis". The results were subject to the inclusion and exclusion criteria. A total of 15 studies were selected. All of the studies were randomized clinical trials. An important number of complications were recorded, such as fractures, dislodgment and wear of the prosthesis structure. There is no evidence about the number and range of sessions needed to assess the clinical control of an immediate loading fixed rehabilitation. The best time to remove the provisional prosthesis and install the restorative rehabilitation is during the third and fourth month following immediate loading. Limited evidence was found regarding the number, time and type of radiological images requested for clinical support. Therefore, the clinical protocol developed by the authors will be a guide for future controls related to an immediately loaded implant-supported prosthesis.

Control Clínico en Pacientes Rehabilitados Mediante Prótesis Fija Total con carga Inmediata. Revisión de la Literatura / Clinical Control of Patients Treated with an Immediately Loaded Implant-Supported Prosthesis. A Systematic Review

RESUMEN: Son varias las complicaciones que se pueden presentar posterior a la instalación de una prótesis fija total con carga inmediata (PFTCI), estas pudiesen generar desde el daño de la estructura protésica provisoria hasta la pérdida de la oseointegración de los implantes dentales. La escasa evidencia sobre el comportamiento clínico que se debe tener posterior a este tipo de tratamiento indica la necesidad de controlar mejor estas complicaciones. En esta revisión narrativa, el 3 de marzo de 2016 se realizó una búsqueda electrónica en la base de datos PubMed. Para poder efectuar una investigación acabada los filtros de búsqueda fueron ajustados de la siguiente manera. Se utilizaron los términos de búsqueda "immediate loading" AND "full arch" AND "Resonance frequency analysis". Los que fueron sometidos a los criterios de inclusión y exclusión, dando como resultado un total de 15 estudios. Todos los estudios eran ensayos clínicos controlados, donde se encontraron complicaciones como fracturas, desalojos y desgaste de la estructura protésica, entre otros. Se pudo observar que desde el día de la carga hasta un mes después el valor ISQ (cociente de estabilidad del implante) disminuye, para luego aumentar paulatina y progresivamente. En conclusión, no existe evidencia sobre el número y rango de sesiones necesarias para el control clínico de una PFTCI. El momento más indicado para la extracción de la prótesis provisoria e instalación de la prótesis definitiva es durante el 3° y 4° mes posterior a la carga inmediata. Existe escasa evidencia sobre el número, momento y tipo de examen imageneológico a solicitar. La presencia de complicaciones protésicas posterior a una PFTCI hace necesaria la confección de un protocolo de control clínico para este tipo de tratamiento.

ABSTRACT: There are many complications that can occur following placement with an immediately loaded implant-supported prosthesis in rehabilitation, these may generate damage to the provisional structure and even loss of the osseointegration from the dental implants. Limited evidence about clinical behavior post-installation, creates the need to better assess possible future complications that may arise. In this review, a systematic research was made in the PubMed database. The filters used were "immediate loading", "full arch" and "Resonance frequency analysis". The results were subject to the inclusion and exclusion criteria. A total of 15 studies were selected. All of the studies were randomized clinical trials, many complications were recorded, such as fractures, dislodgement and wear of the prosthesis structure. It was observed that from the first day of immediate loading until the first month, Implant Stability Quotient value decreases, subsequently, progressively increasing. There is no evidence about the number and range of sessions needed to assess the clinical control of a immediate loading fixed rehabilitation. The ideal time for removal of the provisional prosthesis and installation of the restorative rehabilitation, is during the third and fourth month after the immediate loading. Limited evidence was found regarding the number, the time and type of radiological images for clinical support. The possibility of several complications after an installation of a immediately loaded implant-supported prosthesis are very real, therefore is necessary to establish a clinical protocol for controls regarding this treatment.

Implant inclination and horizontal misfit in metallic bar framework of overdentures: analysis by 3d-fea method

Abstract The aim of this study was to evaluate by three-dimensional finite element analysis (3D-FEA) the biomechanics involved in bar-framework system for overdentures. The studied factors were latero-lateral angulation in the right implant (-10, -5, 0, 5 and 10 degrees), and different bar cross-sections (circular, Hader and oval) presenting horizontal misfits (50 or 150 µm) on the opposite implant. Positive angulation (5 and 10 degrees) for implant inclination to mesial position, negative angulation (-5 and -10 degrees) for distal position, and zero degree for parallel implants. The von Mises stresses evaluated the bar, screw and the implant; maximum principal, minimum principal and shear stress analyses evaluated the peri-implant bone tissue. Parallel implants provide lower stress in alveolar bone tissue; mesial inclined bars showed the most negative effect on prosthetic structures and implants. In conclusion, bar cross-section showed no influence on stress distribution for peri-implant bone tissue, and circular bar provided better behavior to the prosthetic system. Higher stress concentration is provided to all system as the misfit increases.

Resumo O objetivo neste estudo foi avaliar por meio do método por elemento finito tridimensional (3D-AEF) a biomecânica envolvida na infraestrutura do sistema barra-clipe para overdentures. Os fatores de estudo foram inclinação mésio-distal entre implantes (-10, -5, 0, 5, 10 graus) e diferentes seções transversais da barra metálica (circular, oval e Hader) com desajuste horizontal (50 e 150 µm). Valores de inclinação positivas (5 e 10 graus) indicam inclinação do implante para mesial e valores negativos (-5 e -10 graus) mostram inclinação para distal, enquanto zero grau indica implantes paralelos. Valores de tensões equivalentes de von Mises foram utilizadas nos sistemas barra, parafuso e implante. Tensão máxima e mínima principal, e cisalhante foram utilizadas para análise do osso alveolar peri-implante. Implantes paralelos promoveram menores tensões em tecido peri-implante; as inclinações para mesial apresentaram piores resultados para as estruturas protéticas e implantes. As diferentes seções transversais da barra não mostraram influência na distribuição de tensões no osso alveolar peri-implante. Concluindo, a barra circular apresentou melhores resultados para os componentes protéticos e maiores valores de tensões foram observados em todos os modelos na medida que o desajuste aumentou.

Evaluation of the maladaptation of the test base in acrylic resin regarding the technique of preparation, place of measurement and storage time / Avaliação da desadaptação da base de prova em resina acrílica em relação à técnica de confecção, local de mensuração e tempo de armazenagem

Introduction: The most used material for the preparation of the baseplates is the acrylic resin, but it can present distortions. Objective: To evaluate preparation technique, region and storage time that presents less maladaptation of the base when made with self-cured acrylic resin. Material and method: Models were created in gypsum type III simulating edentulous maxilla, as divided into 3 groups (n = 10): GC (control group) thermopolymerizable acrylic resin; G1 - manual adaptation technique and G2 - drip technique. For the measurements, silicone by condensation of light consistency that was interposed between base and model was used. With a hydraulic press, 50 kg pressure was applied leading the base of the model. The obtained mold was measured in the palate, canine and molar regions with a digital caliper at the following times: immediately after the base polymerization, at 24, 48, 72, 96 hours and one week. The results were submitted to statistical analysis. Result: G1 presented maladaptation of 0.43 mm ± 0.10, while G2 obtained 0.39 mm ± 0.11. The lowest maladaptation occurred in the CG. The palate region presented greater maladaptation (0.52 ± 0.07) and the canine region, the lowest (CD = 0.27 mm ± 0.07 and CE = 0.27 ± 0.09); There was no statistically significant difference for storage times. Conclusion: G2 presented lower values than G1, with no statistically significant difference. The palate region presented greater maladaptation, followed by molars and canines. The bases continued to maladaptation the model after the immediate polymerization, with no statistically significant difference.

Introdução: O material mais empregado para confecção da base de prova é a resina acrílica por oferecer maior rapidez e praticidade, embora tenda a maior distorção. Objetivo: Avaliar técnica de confecção, região e tempo de armazenagem que apresente menor desadaptação da base de prova confeccionada com resina acrílica ativada quimicamente. Material e método: Confeccionaram-se modelos em gesso tipo III simulando maxila edêntula que foram divididos em 3 grupos (n = 10): GC - (grupo controle) resina acrílica termopolimerizável; G1 - técnica da adaptação manual; e G2 - técnica do gotejamento. Para as mensurações utilizou-se silicone por condensação de consistência leve que foi interposto entre base e modelo. Com uma prensa hidráulica aplicou-se pressão de 50 kg levando a base de encontro ao modelo. O molde obtido foi mensurado nas regiões de palato, caninos e molares com paquímetro digital nos seguintes tempos: imediatamente após a polimerização da base, em 24, 48, 72, 96 horas e uma semana. Os resultados foram submetidos à análise estatística. Resultado: O G1 apresentou média de desadaptação de 0,43mm±0,10, enquanto o G2 obteve 0,39 mm ± 0,11. Os menores valores de desadaptação ocorreram no GC; A região do palato apresentou maior desadaptação (0,52 mm ± 0,07) e a região de caninos, as menores (CD = 0,27 mm ± 0,07 e CE = 0,27 ± 0,09); Não houve diferença estatisticamente significante para os tempos de armazenagem. Conclusão: O G2 apresentou menores valores que o G1, sem diferença estatisticamente significante; A região de palato apresentou maior desadaptação, seguida de molares e caninos; As bases continuaram desadaptando ao modelo após a polimerização imediata, sem diferença estatisticamente significante.

Prosthetic rehabilitation using an obturator in a fully edentulous patient who had partial maxillectomy

Prosthetic rehabilitation of an edentulous patient who has a maxillary defect is difficult to achieve for many clinicians. The maxillary defect causes leakage of air during pronunciation and compromises denture stability, support and retention by reducing denture-bearing area and breaking peripheral seal. In these patients, the sizes and shapes of defects are very important factors which attribute to prognosis of maxillary obturators. This case report shows the prosthetic rehabilitation of the patient who had maxillectomy on the right maxillary sinus because of squamous cell carcinoma. The patient had a stepwise treatment protocol which started with pre-operative dental examination and followed by surgical, interim and definitive obturation phase. In this case, an acceptable level of retention could be obtained due to well-defined static defects and the preserved premaxillae and the patient was satisfied with the result of the treatment in the aspect of function and esthetics.

Evaluation of suitability and stability in a skeletal Class III complete denture patient with flabby tissue: A case report / 대한치과보철학회지

To obtain denture retention, support, and stability in Class III edentulous cases with flat alveolar ridges and extensive flabby tissue is very difficult. The patient was a 72-year-old male who wore ill-fitting 20 year old dentures made by non-medical institutions. There was flabby tissue on the maxillary anterior ridge. The patient showed Angle Class III skeletal relationship with severe protruded mandible. First, temporary dentures were fabricated to restore the masticatory function, and final dentures were made through non- pressure impression technique and careful the arrangement of the posterior resin teeth. Improvement of the retention and stability of the denture during the occlusal force application is reported.

A new method for evaluating the retentive efficacy of different denture adhesives

Aim: The aim of this study was to evaluate a new method for measuring the retention values of different denture adhesives. Methods: The adhesive strength values of three different commercial denture adhesives (Corega powder, Corega adhesive tape and Ultra Corega cream) were evaluated using three different moisturizing agents (distilled water, artificial saliva and natural saliva). The adhesive test was performed on a universal testing machine, after applying the adhesive products to acrylic resin specimens, under two different test conditions (wetting or dipping). Tensile bond strength values in MPa were obtained for each denture adhesive presentation and test condition. Viscosity of the denture adhesives mixed with the different moisturizing agents was determined using a rotary rheometer. Maximum viscosity values were analyzed using the one-way ANOVA test. Tensile bond strength data was analyzed using Kruskal-Wallis and the Tukey's test. Pooled data of each denture adhesive presentations for all test conditions was also carried out. Correlation between viscosity and pooled tensile strength values was analyzed through linear regression analysis. A significance level of α=0.05 was set for all analyses. Results: Results showed that statistically higher adhesion strength was obtained with tape and cream adhesives when using natural saliva as moisturizing agents (p<0.05). The adhesive strength values obtained with the dipping method were similar to those obtained with the conventional wetting method. The denture retention strength was influenced by both the denture adhesive type and moisturizing agent used. Conclusion: The dipping method showed to be a reliable test capable to simulate the oral conditions and should be better explored in further studies

Odontoma compuesto. presentación de un caso / Odontoma compound. presentation of a case

Se presentó el caso clínico de un niño de 8 años de edad, que acude a consulta de Estomatología del Policlínico "Mártires de Jamaica", del municipio Manuel Tames, de la provincia Guantánamo, acompañado de la madre preocupada por la no erupción del diente 21. Al examen clínico se observó ausencia clínica del 21 con espacio para su ubicación con ligero aumento de volumen en el fondo del surco vestibular a nivel de la zona de consistencia dura a la palpación. Se indicó radiografía panorámica observándose imagen radiolúcida con numerosas formaciones radioopacas en su interior que asemejan estructuras dentarias y una banda radiolúcida en su periferia que presuntivamente se diagnosticó como un odontoma compuesto, se remite al segundo nivel de atención para excéresis y diagnóstico definitivo. Se discuten algunas características de su etiología, diagnóstico y tratamiento(AU)

It was presented the clinical case of an 8-year-old boy, who was attended in the clinic of "Mártires de Jamaica" Polyclinic, in Manuel Tames municipality of Guantanamo province, accompanied by the mother concerned about the non-eruption of tooth 21 .On clinical examination, was observed absence of tooth 21 with space for its location with slight increase in volume at the bottom of the vestibular sulcus at the level of the area hard to palpation. Panoramic x-ray is indicated, with a radiolucent image with numerous radio opaque formations that resemble dental structures and a radiolucent band in its periphery presumptively diagnosed as a compound odontoma. It is referred to the second level of attention for excresis and definitive diagnosis. Some characteristics of its etiology, diagnosis and treatment were discussed(AU)

Factors associated with the non-wear of mandibular dentures in the Brazilian public primary health care

Abstract This study investigated factors that affect the use of complete conventional mandibular dentures (CCMD) by patients of the Brazilian Public Health Service. For this, two hundred and thirty one subjects who received CCMD in the Primary Health Care of the Public Health Service in Belo Horizonte - Brazil were evaluated and divided in Group 1 - irregular/non-wear; Group 2 - regular wear. Multivariate logistic regression analysis was used to create predictive models for CCMD non-wear and included socio-demographic and biological variables, technical quality of CCMD, and user satisfaction. The prevalence of CCMD non-wear was 41.10%. The mean score of CCMD quality was 54.97 (0-100). Not wearing the CCMD was significantly associated with user satisfaction and technical quality (p < 0.05). The lack of retention of the CCMD was the most important factor in the evaluation of satisfaction and quality. The final predictive model (specificity = 92.65%; AROC = 0.8759) for not wearing the CCMD retained the variables CCMD stability (OR = 0.888; 95%CI = 0.827-0.954), freeway space (OR = 0.916; 95%CI = 0.860-0.976), satisfaction with speech (OR = 0.694; 95%CI = 0.612-0.786), and irregular CCMD edges (OR = 3.185; 95%CI = 1.478-6.864). Socio-demographic and biological variables were not associated with patients not wearing the CCMD, whereas technical quality and user satisfaction were strongly associated.

One-year prospective clinical study comparing patient satisfaction and masticatory performance of mandibular overdentures supported by one versus two implants

Abstract There is a lack of clinical evidence on mandibular overdentures (MOD) supported by a single implant. Objective: To compare patient satisfaction and masticatory performance in MOD supported by one versus two implants in a two-group parallel randomized clinical trial. Material and Methods: Twenty-one patients wearing new maxillary and mandibular complete dentures (CDs) were randomly divided to receive one (GI, n = 11) or two (GII, n = 10) implants in the mandibular arch. Four months after implant placement, o-ring abutments were installed in the implants, and matrix attachments were placed in the lower complete dentures. Patient satisfaction with their dentures and masticatory performance were compared at baseline, 3, 6, and 12 months after the procedure. Data on patient satisfaction were analyzed using the Friedman test and the Mann-Whitney U test. Data on masticatory performance were analyzed using one-way repeated measures analysis of variance (ANOVA) and Student's t test (α=0.05). Results: Both groups exhibited a significant increase in overall patient satisfaction in all periods evaluated (p<0.05), except for GI after 12 months, which had values similar to baseline (p=0.74). Satisfaction levels of GI and GII were similar at baseline, 3 and 6 months, but GII showed higher satisfaction levels (p=0.01) than GI at 12 months. GI and GII exhibited a significant increase (p<0.05) in masticatory performance for all periods relative to baseline. However, GII had higher masticatory performance with dentures than GI, regardless of the period (p<0.05). Conclusion: MOD supported by two implants demonstrated better patient satisfaction in the follow-up at 12 months and better masticatory performance than MOD supported by one implant.

Clinical application of mandibular removable partial denture using implant-supported surveyed crown: A case report / 대한치과보철학회지

When making conventional removable partial denture for the remaining teeth where the remaining teeth are only on one side, rotation of the denture occurs -in function- on the axis of the connected remaining teeth. If the edentulous portion is long, it becomes harder to obtain retention and stability for the abutment as the importance of the mucous membrane support is elevated. Such movements of denture decrease denture retention and stability, put excessive stress on the abutment, and give bad influence on periodontal health. Therefore, additional implant placement can be of a good choice in gaining additional retention and stability for partial denture. Thus hereby we report this clinical case as successful results were obtained by placing implants symmetrical to the remaining teeth and putting implant-supported surveyed crowns on the implants, allowing the partial denture to be designed to accept varying components and to have suitable path of insertion.

Fabrication of complete dentures for a patient with odontogenic myxoma: A case report / 대한치과보철학회지

Odontogenic myxoma of the jaws is a rare benign odontogenic tumor. In this case, a 61-year-old male patient had a chief complaint about maxillary anterior gingival mass and excisional biopsy result confirmed odontogenic myxoma. The clear acrylic resin custom tray was designed to minimize displacement of flabby tissue which remained after the surgery. Neutral zone and external impression technique could provide satisfactory result in terms of denture stability and retention during jaw relation record and wax denture try-in procedure. This clinical report describes fabrication of complete dentures for a patient with odontogenic myxoma in regard to flabby tissue and neutral zone.