Optimisation de la prothèse complète supra-radiculaire mandibulaire par l'usage de l'attachement barre: rapport de cas / Optimization of the mandibular supra-radicular complete prosthesis by the use of the bar attachment: a case report

Introduction : L'équilibre d'une prothèse complète amovible mandibulaire est délicat vu la surface d'appui restreinte. L'objectif du travail était de décrire l'intérêt de la prothèse amovible supra-radiculaire retenue par l'attachement barre dans la gestion d'un édentement subtotal mandibulaire. Observation : Un patient consultait pour bénéficier d'une prothèse esthético-fonctionnelle. L'examen clinique montrait la présence d'un édentement total maxillaire et subtotal mandibulaire avec persistence des canines séparées d'une crête rectiligne. L'examen radiologique révélait un rapport couronne sur racine radiologique égal à 1. L'examen des moulages sur articulateur visualisait une hauteur occlusale utilisable suffisante. La décision prothétique était une prothèse complète maxillaire et une prothèse complète supra-radiculaire (PCSR) mandibulaire retenue par une barre. Le traitement prothétique commençait par une préparation Richmond des plateaux radiculaires. Après sculpture des chapes et fixation de la barre calcinable, la coulée était faite. Une empreinte anatomo-fonctionnelle de situation était réalisée pour confectionner l'infrastructure métallique. Suite à l'enregistrement de l'occlusion, le montage des dents était fait et validé. Le jour de la mise en bouche des conseils d'utilisation et de maintenance étaient prodigués au patient. Commentaires : La PCSR est avantageuse par le maintien du système proprioceptif desmodontal et d'un profil de crête favorable à l'appui. Les racines à conserver doivent valider certains critères pour être exploitables. La barre offre une rétention importante, mais son indication dépend du parallélisme radiculaire, de l'espace prothétique utilisable et de la forme de la crête édentée. Conclusion : Le recours aux attachements en PCSR est intéressant à condition d'établir un plan de traitement rigoureux et d'assurer la maintenance post-prothétique.

Introduction: The balance of a complete removable mandibular prosthesis is delicate given the limited support area. The objective of this work was to describe the benefit of the supra-radicular removable prosthesis retained by the bar attachment in the management of subtotal mandibular edentulism. Observation: A patient consulted to benefit from an aesthetical and functional prosthesis. The clinical examination showed the presence of total maxillary and subtotal mandibular edentulism with persistence of the canines separated by a straight ridge. The radiological examination revealed a crown by radiological root ratio equal to 1. Examination of the casts on the articulator visualized sufficient usable occlusal height. The prosthetic decision was a maxillary complete prosthesis and a mandibular complete supra-radicular prosthesis (CSRP) retained by a bar attachment. The prosthetic treatment began with a Richmond preparation of the root plates. After sculpting the copings and fixing the castable bar, the casting was done. An anatomo-functional impression was made to perform the metal infrastructure. Following the occlusion recording, the assembly of the teeth was done and validated. On the day of denture insertion, instructions about the use and the maintenance was provided to the patient. Comments: PCSR is advantageous by maintaining the periodontal proprioceptive system and a favorable ridge profile for prosthetic bearin. The roots to be kept must validate certain criteria to be usable. The bar offers significant retention, but its indication depends on the root parallelism, the usable prosthetic space and the shape of the edentulous ridge. Conclusion: The use of attachments in CSRP is interesting provided that a rigorous treatment plan is established and post-prosthetic maintenance is ensured.

Prevalencia del Síndrome de Combinación y sus factores asociados en la Clínica de la Facultad de Odontología de la Universidad de Cuenca, periodo 2015-2016 / Prevalence of Combination Syndrome and associated factors at Clínica de la Facultad de Odontología, Universidad de Cuenca, 2015-2016

INTRODUCCIÓN: Un conjunto de cambios patológicos en el sistema estomatognático frente a la pre-sencia de una prótesis total maxilar y una prótesis parcial removible mandibular han sido descritos como el Síndrome de Combinación. El objetivo de este estudio fue determinar la prevalencia del sín-drome y si factores como la edad, el sexo o el tipo de edentulismo mandibular están asociados al mis-mo en los pacientes de la Clínica de la Facultad de Odontología de la Universidad de Cuenca período 2015-2016. MÉTODOS: Estudio observacional,transversal, descriptivo y de correlación. La muestra estuvo cons-tituida por 312 pacientes edéntulos. Se estableció la presencia del síndrome de combinación cuando un paciente presentaba un mínimo de tres signos asociados. Se determinó la prevalencia del síndro-me de combinación en la muestra y la asociación entre las variables sexo, edad, tipo de edentulismo con la presencia de síndrome de combinación. RESULTADOS: La prevalencia del SC resultó en un 21.8%. Padecer de edentulismo parcial clase I de Kennedy (3.6 veces mayor probabilidad que los otros tipos de edentulismo) y ser adulto mayor de 60 años (1.8 veces mayor probabilidad), tuvieron asociación con el desarrollo del síndrome de Combinación. CONCLUSIÓN: La prevalencia de SC es del 21.8%, la progresión de la edad y el edentulismo parcial clase I de Kennedy conducen a una mayor probabilidad para desarrollar el síndrome de combinación y deben evaluarse como factores de riesgo.(au)

BACKGROUND: The set of pathological changes in the stomatognathic system in the presence of a total maxillary prosthesis and a removable partial mandibular prosthesis has been described as the Combi-nation Syndrome. The main purpose of this study was to determine its prevalence and if features such as age, sex or type of mandibular edentulism are associated with the syndrome in the patients of the Odontologic Clinic of the of Faculty of Dentistry, Universidad de Cuenca during the academic period 2015-2016. METHODS: Cuantitative, cross sectional descriptive and correlational study. The sample consisted of 312 edentulous patients. The diagnosis of the syndrome in this study was determined by the presence of a minimum of three associated signs. We determine the prevalence of combiantion syndrome and the as-sociation between sex, age and edentulism type and combination syndrome. RESUlTS: The prevalence of combination syndrome is 21.8%. Adults 60 years or older (1.8 times higher probability) and patients who suffer from Kennedy class I partial edentulism (3.6 times higher probability than other types of edentulism), have a higher probability for developing the syndrome. CONClUSION: The prevalence of CS was 21.8%, age and suffering from Kennedy class I partial edentulism should be considered as risk factors for developing the syndrome.(au)

Evaluation of the inclination effect of non-splinted implants on the prosthetic behavior of overdentures in mandible edentulous patients / Evaluación del efecto de la inclinación de implantes no ferulizados sobre el comportamiento protésico de sobredentaduras en pacientes desdentados mandibulares

ABSTRACT. Introduction: the aim of this study was to evaluate the sagittal inclination of implants with respect to the occlusal plane of mandibular overdentures and their effect on the prosthetic behavior of the overdentures. Methods: 52 implants were evaluated in 26 fully mandible edentulous adults (two interforaminal implants per patient), rehabilitated with ball attachments and overdenture. Cephalometric tracing was conducted, evaluating the sagittal inclination of the implant to mandibular plane (MI), occlusal plane (OI), compensation angle (CA), and anterior facial height. The following clinical variables of prosthetic behavior were assessed: the need for prosthesis rebasing, changes in prosthetic accessories, and loosening of the prosthetic attachment. The variables were described with measurements of central tendency and dispersion. Intragroup comparisons were made with the Student's t test (p < 0.05) and correlations with the Pearson coefficient. Results: 26 patients were evaluated: 70.4% females and 29.6% males. The average age was 67.93 ± 8.6 years. The follow-up period ranged from 24 to 30 months. The average MI was 78.89 ± 10.9 degrees. There was a statistically significant correlation (r = 0.6) between MI and OI in patients who underwent a change in accessories and between MI and bone loss (r = 0.557) (p = 0.007). The average MI was higher in patients subjected to rebasing (89.70 ± 11.7 degrees), compared with those who were not subjected to rebasing (76.91 ± 9.8 degrees). A relationship with prosthetic pillar loosening could not be determined. Conclusions: the sagittal inclination of implants with respect to the occlusal plane in overdentures affects bone loss, leading to a change of accessories as well as prosthesis rebasing after two years of service.

RESUMEN. Introducción: el objetivo del presente estudio consistió en evaluar la inclinación sagital de los implantes con respecto al plano oclusal de sobredentaduras mandibulares y su efecto sobre el comportamiento protésico de las mismas. Métodos: se evaluaron 52 implantes en 26 adultos desdentados totales inferiores (dos implantes interforaminales por paciente), rehabilitados con pilares tipo bola y sobredentadura. Se realizaron trazos cefalométricos y se evaluó la inclinación sagital del implante con respecto al plano mandibular (MI), el plano oclusal (OI), el ángulo de compensación (CA) y la altura facial anterior. Se evaluaron variables clínicas de comportamiento protésico: necesidad de rebase de la prótesis, cambio de aditamentos retentivos y aflojamiento del pilar protésico. Las variables se describieron con medidas de tendencia central y dispersión. Las comparaciones intragrupales se hicieron con prueba t de Student (p < 0,05), y las correlaciones con el coeficiente de Pearson. Resultados: se evaluaron 26 pacientes: 70,4% mujeres y 29,6% hombres. La edad promedio fue de 67,93 ± 8,6 años. El rango de seguimiento fue de 24 a 30 meses. El MI promedio fue de 78,89 ± 10,9 grados. Hubo una correlación (r = 0,6) estadísticamente significativa entre MI y OI en los pacientes a quienes se les realizó cambio de aditamentos y entre MI y la pérdida ósea (r = 0,557) (p = 0,007). La MI promedio fue mayor en aquellos pacientes a quienes se les hizo rebase (89,70 ± 11,7 grados), en comparación con los que no tuvieron rebase (76,91 ±9,8 grados). No se pudo determinar la relación con el aflojamiento del pilar protésico. Conclusiones: la inclinación sagital de los implantes con respecto al plano oclusal de las sobredentaduras tiene un efecto sobre la pérdida ósea, lo que conlleva al cambio de aditamentos y rebase de la prótesis después de dos años de observación.

Removable Partial Denture Using Anterior Implant-Supported Fixed Prostheses for Edentulous Patients: A Case Report

This case study was to report the possible increase in the denture retention and psychological relief using the implant-supported fixed prostheses in a completely edentulous patient. The implants were placed in the anterior portion of the mandible in a patient who had completely edentulous state following the extraction of residual abutment teeth, and consequently a distal extension removable partial denture was fabricated. The patient's adaptation and satisfaction to the new prosthesis was monitored and confirmed in terms of masticatory function and esthetics, by restoring the oral condition similar to initial status before the residual teeth extraction. After 6 months, radiographic examination confirmed that both the abutment teeth and the implants were stable and well maintained. Considering the relatively short clinical follow-up period, however, continuous long-term monitoring was required.

Short-term quality of life change perceived by patients after transition to mandibular overdentures

Abstract The aim of this longitudinal observational study was to evaluate the oral health-related quality of life (OHRQoL) following patient rehabilitation with implant-retained mandibular overdentures (IMO) and to identify the contribution of the different domains to OHRQoL. The Oral Health Impact Profile (OHIP-EDENT), Dental Impact on Daily Living (DIDL), and Geriatric Oral Health Assessment Index (GOHAI) questionnaires were completed twice by 25 patients: after 3 months of rehabilitation with complete dentures (CD) and after 3 months of IMO loading using stud abutments. The evaluation after IMO rehabilitation showed significant improvement in three DIDL domains: appearance (p = 0.011), eating and chewing (p = 0.003), and general performance (p = 0.003). The GOHAI results showed significant differences in two domains: psychosocial (p = 0.005) and pain and discomfort (p = 0.0004). The OHIP-EDENT outcomes showed significant improvements in five domains: functional limitation (p = 0.0001), physical pain (p = 0.0002), physical disability (p = 0.0010), and psychological disability and handicap (p = 0.032). The largest observed effect sizes were close to one standard deviation and were observed in the eating and chewing domain (0.93) of the DIDL; the pain and discomfort domain (0.83) of the GOHAI, and the functional limitation (0.89), physical pain (1.02), physical disability (0.84) domains of the OHIP-EDENT. The percentage of satisfied patients increased in all domains. Self-reported OHRQoL of CD wearers was significantly improved after 3 months of treatment with IMO, especially concerning the functional and pain-related aspects.

Accuracy of partially edentulous arch impressions obtained from different alginates and storage times

Purposes: This study aimed to assess the dimensional accuracy of five commercial alginates verified in stone casts. Methods: Each alginate impression (Cavex ColorChange, Cavex Holland BV; Jeltrate Plus, Dentsply; Hydrogum, Zhermack; Kromopan 100, Lascod; Ezact Kromm, Vigodent) was performed on partially edentulous standard stainless steel mandibular arch cast with reference points on teeth 33, 43, 37 and 47. On the stainless steel cast, the anteroposterior (33-37 and 43-47) and transverse (33-43 and 37-47) distances were measured in a stereomicroscope at 30x magnification and 0.5 µm accuracy. The distances between these points were measured three times, obtaining an average, which was analyzed statistically and compared with the distances obtained from the stone casts. For each alginate the casts were poured gypsum (n = 5) immediately and after a period of 1, 2, 3 and 5 days of the impression procedure. Results: The dimensional accuracy values of stone and stainless steel casts were analyzed statistically by two-way ANOVA and Tukey's test (α=0.05). The results showed significant differences between the alginates; however, no differences in dimensional accuracy were found among the different storage times of alginate impression. Conclusions: It can be concluded that the alginate impressions can be stored for up to 5 days (AU)

Análise da distribuição das tensões em próteses protocolo mandibulares com estruturas fresadas por CAD/CAM e confeccionadas pela técnica convencional: análise pela fotoelasticidade e extensometria / Analysis of stress distribution in full-arch fixed mandibular prosthesis with structures made with the CAD/CAM technology and with the conventional technique: evaluation through photoelastic and strain gauge analysis

O objetivo desse estudo foi avaliar a distribuição de tensão, por meio dos métodos fotoelástico e extensometria, em próteses protocolo mandibulares (tipo Branemärk) com infraestruturas confeccionadas com diferentes materiais e técnicas, sob força de compressão. Foi confeccionado um modelo fotoelástico de uma mandíbula edêntula que recebeu cinco implantes 4x11 mm hexágono externo entre os forames mentonianos. Os grupos foram divididos em: Grupo I - infraestrutura fundida em níquel-cromo com revestimento oclusal em resina acrílica (n=7); Grupo II - infraestrutura fundida em níquelcromo com revestimento oclusal em cerâmica (n=7); Grupo III - infraestrutura fresada em Zircônia estabilizada por óxido de ítrio com revestimento em cerâmica (n=7). Inicialmente, foi realizado o teste da fotoelasticidade e, posteriormente, a extensometria. Pela metodologia da fotoelasticidade, com auxílio de uma máquina de ensaio universal (EMIC) foram aplicadas cargas axiais de 70 N na região do implante mais anterior, entre osincisivos, e no centro do primeiro molar de cada lado. Por meio de imagens fotográficas e com o auxílio do programa Adobe Photoshop CS6, as imagens foram analisadas de acordo com o número de franjas de alta intensidade nos grupos testados. Para a metodologia da extensometria, as cargas foram aplicadas da mesma maneira da metodologia da fotoelasticidade e a medição das tensões foi realizada em duas regiões distintas. Para a primeira região, dois extensômetros elétricos de resistência foram posicionados horizontalmente na região mesial e distal dos cinco implantes, diretamente sobre a crista marginal do modelo fotoelástico. Para a segunda região, a resina fotoelástica foi removida da superfície vestibular e lingual de cada implante, sendo mantida1 mm de resina intacta, onde os extensômetros foram fixados verticalmente. Foram realizados os mesmos testes de compressão descritos anteriormente. Os valores de tensão registrados foram agrupados em tabelas e submetidas à análise de variância (ANOVA) dois fatores e ao teste de Tukey com significância de 5%. Os resultados das duas metodologias demonstraram menores valores de tensão para o Grupo I, quando comparado aos demais grupos. É possível concluir que as próteses protocolo com infraestrutura fundida em metal e revestimento oclusal acrílico demonstraram melhores resultados biomecânicos(AU)

This study aimed to evaluate the stress distribution in full-arch fixed mandibular prosthesis (Branemärk type) with infrastructure made of different materials and techniques, and under compressive force, through photoelastic and strain gauge analysis. A photoelastic cast of an edentulous jaw was fabricated and received five external hexagon implants (4x11mm) between the mental foramen. The groups were divided into: Group I - Nickel-Chrome fused infrastructure with acrylic resin occlusal coating; Group II - Nickel-Chrome fused infrastructure with ceramic occlusal coating; Group III ­ Yttriastabilized zirconia fused infrastructure with ceramic coating. First, the photoelastic analysis was performed and later the strain gauge analysis. A force of 70 N was applied by using a testing machine (EMIC) in the region of the most anterior implant, between incisors, and in the center of the first molar on each side. The images were analyzed by a blinded evaluator through images and by using Adobe Photoshop CS6, according to the number of high intensity fringes in each group. Regarding the strain gauge analysis, the stress measure was performed in two distinct regions. For the first region, two resistance strain gauges were placed horizontally in the mesial and distal regions of the five implants, directly on the marginal ridge of the photoelastic cast. For the second region, the photoelastic resin was removed on the buccal and lingual surfaces of each implant, leaving 1 mm of intact resin, where the strain gauges were placed vertically. The same compression tests described above were carried out. Data were submitted to two-way ANOVA and to the Tukey post-hoc test with 5% level of significance. The results of both methods showed lower stress values for Group I, when compared to other groups. It can be concluded that when rigid materials are used for infrastructure fabrication, the esthetic coating influences the load generated on the marginal bone around the implant. The ceramic coating showed less satisfactory results(AU)

Marginal bone loss around tissue level implants in the posterior part of the mandible / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To clarify the related factors of marginal bone loss (MBL) around tissue level implants in the posterior part of the mandible.</p><p><b>METHODS</b>A total of 116 tissue level implants were implanted in the mandibular posterior region of 76 patients. Patients' information, including general characteristics, implant characteristics, implant site characteristics, and prosthesis characteristics, was recorded. Their cone beam computed tomography data were measured immediately after implant placement, 3 months later, and 3 and 12 months after prosthesis loading. The measurement of MBL was conducted by One Volume Viewer software. SPSS 20.0 was used for statistic analysis.</p><p><b>RESULTS</b>Smoking, cortical bone thickness (CBT), collum angle (CA), and implant local sanitation showed significant differences with body mass loss (P<0.05). No significant differences were found among sex, age, length of implant, diameter of implants, implant systems, bone height, prosthesis type, and MBL (P>0.05).</p><p><b>CONCLUSION</b>The risk factors that caused MBL were smoking, thicker CBT, larger CA, and poor implant local sanitation. Among them, poor implant local sanitation had the highest correlation with MBL.</p>

Analysis of maxillofacial prosthetics at university dental hospitals in the capital region of Korea

PURPOSE: The purpose of this study was to investigate the demographic patterns of maxillofacial prosthetic treatment to identify the characteristics and geographic distribution of patients with maxillofacial prosthetics in the capital region of Korea. MATERIALS AND METHODS: This retrospective analytical multicenter study was performed by chart reviews. This study included patients who visited the department of prosthodontics at four university dental hospitals for maxillofacial prosthetic rehabilitation. Patients with facial and congenital defects or with insufficient medical data were excluded. The patients were classified into three categories based on the location of the defect. Patients' sex, age, and residential area were analyzed. Pearson's chi-square test with a significance level of 0.05 was used to analyze the variables. RESULTS: Among 540 patients with maxillofacial prosthetics, there were 284 (52.59%) male patients and 256 (47.41%) female patients. The number of the patients varied greatly by hospital. Most patients were older than 70, and the most common defect was a hard palate defect. Chi-square analysis did not identify any significant differences in sex, age, and distance to hospital for any defect group (P>.05). CONCLUSION: The results of this study indicated that there was imbalance in the distribution of patients with maxillofacial prosthetic among the hospitals in the capital region of Korea. Considerations on specialists and insurance policies for the improvement of maxillofacial prosthetics in Korea are required.

Standardizing the evaluation criteria on treatment outcomes of mandibular implant overdentures: a systematic review

PURPOSE: The aim of this review was to analyze the evaluation criteria on mandibular implant overdentures through a systematic review and suggest standardized evaluation criteria. MATERIALS AND METHODS: A systematic literature search was conducted by PubMed search strategy and hand-searching of relevant journals from included studies considering inclusion and exclusion criteria. Randomized clinical trials (RCT) and clinical trial studies comparing attachment systems on mandibular implant overdentures until December, 2011 were selected. Twenty nine studies were finally selected and the data about evaluation methods were collected. RESULTS: Evaluation criteria could be classified into 4 groups (implant survival, peri-implant tissue evaluation, prosthetic evaluation, and patient satisfaction). Among 29 studies, 21 studies presented implant survival rate, while any studies reporting implant failure did not present cumulative implant survival rate. Seventeen studies evaluating peri-implant tissue status presented following items as evaluation criteria; marginal bone level (14), plaque Index (13), probing depth (8), bleeding index (8), attachment gingiva level (8), gingival index (6), amount of keratinized gingiva (1). Eighteen studies evaluating prosthetic maintenance and complication also presented following items as evaluation criteria; loose matrix (17), female detachment (15), denture fracture (15), denture relining (14), abutment fracture (14), abutment screw loosening (11), and occlusal adjustment (9). Atypical questionnaire (9), Visual analog scales (VAS) (4), and Oral Health Impact Profile (OHIP) (1) were used as the format of criteria to evaluate patients satisfaction in 14 studies. CONCLUSION: For evaluation of implant overdenture, it is necessary to include cumulative survival rate for implant evaluation. It is suggested that peri-implant tissue evaluation criteria include marginal bone level, plaque index, bleeding index, probing depth, and attached gingiva level. It is also suggested that prosthetic evaluation criteria include loose matrix, female detachment, denture fracture, denture relining, abutment fracture, abutment screw loosening, and occlusal adjustment. Finally standardized criteria like OHIP-EDENT or VAS are required for patient satisfaction.

Distribuição das tensões em próteses protocolo mandibulares com diferentes extensões de cantilever e material de revestimento oclusal / Stress distribution in mandibular Branemark's with different cantilevers lengths and coating materials

Neste estudo objetivamos a avaliação da distribuição de tensões na interface osso/implante, por meio do método da fotoelasticidade, em próteses mandibulares tipos protocolos de Branemark, com diferentes extensões de cantilever, materiais de recobrimento estético e uso de intermediários. Foi confeccionado um modelo fotoelástico de uma mandíbula edêntula, contendo cinco implantes 4.0x13 mm hexágono externo (HE) entre os forames mentonianos. Os grupos foram divididos da seguinte forma: Grupo 1 – UCLA e barra metálica; Grupo 2 – UCLA e revestimento oclusal em resina acrílica; Grupo 3 – UCLA e revestimento em cerâmica; Grupo 4 – Intermediário e barra metálica; Grupo 5 – Intermediário e revestimento em resina acrílica; Grupo 6 – Intermediário e revestimento em cerâmica. Com auxílio de uma máquina de ensaio EMIC inicialmente as forças de 70 N foram aplicadas em um ponto anterior, no implante mais posterior e em diferentes extensões de cantilever (até 37,5mm do último implante) na barra metálica e posteriormente nas próteses confeccionadas com barra metálica e revestimento em cerâmica e resina acrílica. Por meio de imagens fotográficas e auxílio do programa Adobe Photoshop CS6 nas imagens obtidas após o teste foi realizada a análise das tensões de acordo com o número de franjas de alta intensidade e de acordo com a concentração e área de distribuição dessas tensões nos grupos testados. Os resultados mostraram um maior número de franjas de alta tensão com o aumento do cantilever, e melhor distribuição das tensões foram para os grupos com as próteses confeccionadas em resina acrílica e para os grupos que continham componente intermediário. Concluímos que o uso de intermediários com próteses protocolo em resina acrílica e a ausência do cantilever tende a apresentar menores números de franjas de alta tensão ao redor dos implantes...

The aim of this study was to assess the stress distribution, through photoelastic method, on mandibular implant-supported prostheses (Brånemark protocol), associated with different cantilever lengths, aesthetic coating materials and implant abutment. One photoelastic model of an edentulous mandible was made. The model contained five external hexagon implants (HE) with 4.0mm diameters and 13mm lengths placed between the mental foramen. The groups were divided as follows: Group 1 - UCLA and metal bar; Group 2 - UCLA and occlusal acrylic resin coating; Group 3 - UCLA and porcelain coating; Group 4 - Abutment and metal bar; Group 5 - Abutment and acrylic resin coating; Group 6 - Abutment and porcelain coating. A force was applied, using a universal testing machine (EMIC), in different regions - in the most anterior implant, in the most posterior implant and in different cantilever extensions (up to 37.5 mm from the last implant) - in the metal bar and later in the metal bar with porcelain and acrylic resin coated prostheses. The results were obtained through photograph images and the Adobe Photoshop CS6 software was used for qualitative analysis. The analysis was performed according to the number of fringes with high intensity and to the stress distribution area. The results showed a greater number of high stress fringes as the cantilever extension increases. Groups with acrylic resin coating and with abutments exhibited greater stress distribution. We concluded that the use of abutments in acrylic resin protocol prostheses and the absence of the cantilever tends to decrease stress around implants...

Attachment systems for mandibular implant overdentures: a systematic review

PURPOSE: The aim of this systematic review was to address treatment outcome according to attachment systems for mandibular implant overdentures in terms of implant survival rate, prosthetic maintenance and complications, and patient satisfaction. MATERIALS AND METHODS: A systematic literature search was conducted using PubMed and hand searching of relevant journals considering inclusion and exclusion criteria. Clinical trial studies on mandibular implant overdentures until August, 2010 were selected if more than one type of overdenture attachment was reported. Twenty four studies from 1098 studies were finally included and the data on implant survival rate, prosthetic maintenance and complications, patient satisfaction were analyzed relative to attachment systems. RESULTS: Four studies presented implant survival rates (95.8 - 97.5% for bar, 96.2 - 100% for ball, 91.7% for magnet) according to attachment system. Ten other studies presented an implant survival rate ranging from 93.3% to 100% without respect to the attachment groups. Common prosthetic maintenance and complications were replacement of an assay for magnet attachments, and activation of a matrix or clip for ball or bar attachments. Prosthetic maintenance and complications most commonly occurred in the magnet groups. Conflicting findings were found on the rate of prosthetic maintenance and complications comparing ball and bar attachments. Most studies showed no significant differences in patient satisfaction depending upon attachment systems. CONCLUSION: The implant survival rate of mandibular overdentures seemed to be high regardless attachment systems. The prosthetic maintenance and complications may be influenced by attachment systems. However patient satisfaction may be independent of the attachment system.

Number of implants for mandibular implant overdentures: a systematic review

PURPOSE: The aim of this systematic review is to address treatment outcomes of Mandibular implant overdentures relative to implant survival rate, maintenance and complications, and patient satisfaction. MATERIALS AND METHODS: A systematic literature search was conducted by a PubMed search strategy and hand-searching of relevant journals from included studies. Randomized Clinical Trials (RCT) and comparative clinical trial studies on mandibular implant overdentures until August, 2010 were selected. Eleven studies from 1098 studies were finally selected and data were analyzed relative to number of implants. RESULTS: Six studies presented the data of the implant survival rate which ranged from 95% to 100% for 2 and 4 implant group and from 81.8% to 96.1% for 1 and 2 implant group. One study, which statistically compared implant survival rate showed no significant differences relative to the number of implants. The most common type of prosthetic maintenance and complications were replacement or reattaching of loose clips for 2 and 4 implant group, and denture repair due to the fracture around an implant for 1 and 2 implant groups. Most studies showed no significant differences in the rate of prosthetic maintenance and complication, and patient satisfaction regardless the number of implants. CONCLUSION: The implant survival rate of mandibular overdentures is high regardless of the number of implants. Denture maintenance is likely not inflenced substantially by the number of implants and patient satisfaction is typically high again regardless os the number of implants.

Guide flange prosthesis for early management of reconstructed hemimandibulectomy: a case report

Surgical resection of the mandible due to presence of benign or malignant tumor is the most common cause of the mandibular deviation. Depending upon the location and extent of the tumor in the mandible, various surgical treatment modalities like marginal, segmental, hemi, subtotal, or total mandibulectomy can be performed. The clinicians must wait for extensive period of time for completion of healing and acceptance of the osseous graft before considering the definitive prosthesis. During this initial healing period prosthodontic intervention is required for preventing the mandibular deviation. This case report describes early prosthodontic management of a patient who has undergone a reconstructed hemi-mandibulectomy with modified mandibular guide flange prosthesis. The prosthesis helps patient moving the mandible normally without deviation during functions like speech and mastication.

Avaliação da distribuição de tensões em casos de prótese parcial removível de classe 1 mandibular convencional e associada a implante osseointegrado pelo método dos elementos finitos / Evaluation of the distribution of tensions in cases of inferior removable partial denture class 1 conventional and associated with osseointegrated implant by the finite element analysis

A associação das próteses parciais removíveis (PPRs) e implantes osseointegrados tem sido relatada na literatura, mas ainda não existem relatos sobre a melhor forma de conexão com o último dente suporte nos casos de extremidade livre. Assim, o objetivo deste trabalho foi estudar, através do MEF bidimensional, o comportamento das estruturas de suporte de uma PPR convencional e associada a implante osseointegrado, agindo apenas como suporte, variando-se os sistemas de conexão com o último dente suporte entre apoio distal e placa distal. Foram confeccionados 4 modelos hemi-mandibulares, com presença apenas do dente 33, sendo: Mod A, PPR convencional e apoio distal; Mod B, PPR convencional e placa distal; Mod C, PPR associada a implante de 3,75 x 10,0 mm e apoio distal; Mod D, PPR associada a implante de 3,75 x 10,0 mm e placa distal. O programa de elementos finitos utilizados foi o ANSYS 9.0 com carregamento de 50N em cada ponta de cúspide, estritamente vertical. Os resultados foram obtidos através de mapas de deslocamento e tensão de Von Mises. Os resultados mostraram alívo do ligamento periodontal e dente suporte quando da presença da placa distal, tanto nos mapas de deslocamento quanto nos mapas de tensão. Por esta metodologia foi possível concluir que: 1. A placa distal diminuiu a tendência de movimento do dente suporte, tanto dos modelos com PPR convencional, quanto nos associados a implante; 2. Os modelos que incorporaram a placa distal melhoraram a distribuição interna de tensões de von Mises, principalmente pelo alívio do dente suporte.

The association of the removable partial dentures (RPDs) and osseointegrated implants it has been mentioned in the literature, but reports don’t still exist on the best connection form with the last support tooth in the cases of distal extension. Like this, the objective of this work was to study, through the bidimensional FEA, the behavior of the support structures of a conventional RPD and associated with implants, just acting as support, by variation in the connection systems with the last support tooth between distal incisal rest or and distal plate. 4 hemi-mandibular models were made, with presence just of the tooth 33: Model A: conventional RPD and distal incisal rest; Model B: conventional RPD and distal plate; Model C: RPD associated with implant (3,75 x 10,0 mm) and distal incisal rest; Model D: RPD associated with implant (3,75 x 10,0 mm) and distal plate. The finite element program used was ANSYS 9.0 with loading of 50N in each cusp tip, strictly vertical. The results were obtained through displacement maps and tension maps. The results showed decrease of the ligament and support tooth tension when distal plate were present, as in the displacement maps or in the tension maps. For this methodology it was possible conclude: 1. The distal plate reduced the tendency of movement of the support tooth in all models; 2. the models that incorporated the distal plate improved the internal distribution of von Mises tensions, mainly for the relief of the support tooth.

Reconstrucción mandibular a medida con prótesis HTR-PMI con esqueleto de titanio / Patient matched mandibular reconstruction with HTR-PMI prosthesis with titanium framework

La prótesis HTR-PMI (hard tissue replacement - patient matched implant) es una prótesis reconstructiva compuesta por una combinación de materiales: un polímero de polimetilmetacrilato y polihidroxietilmetacrilato, no reabsorbible, biocompatible, aloplástico, indicado para la reparación de defectos esqueletales. El objetivo de este trabajo es presentar un caso clínico de reconstrucción mandibular post-osteomielitis de injerto libre de cresta ilíaca, por resección de un ameloblastoma invasivo, con un seguimiento de 7 años. El uso de este tipo de prótesis ofrece una alternativa más para la reconstrucción de grandes defectos.

A study on individual mandibular prostheses according to 3D reconstruction of CT images and CNC simulation method / 中国医疗器械杂志

The new method of manufacturing individual mandibular prostheses, in combination with CT data and CNC technique, can duplicate bone tissues accurately, and can have the individual mandibular prosthesis made to order, and repair the mandibular defect (especially the lager mandibular segmental defect).

Reconstrução de mandíbula severamente reabsorvida usando a técnica da tenda de tecido mole – Relato de caso / Severely atrophic mandible reconstruction using the soft tissue matrix technique - Case report

As técnicas de reconstrução óssea na mandíbula são muito usadas para permitir a reabilitação com implantes. A mandíbula severamente reabsorvida (6 mm ou menos) ainda permanece como um desafio em razão das taxas de insucesso e risco de fratura mandibular. Os autores apresentam um caso de reconstrução de mandíbula severamente reabsorvida usando a técnica da tenda de tecido mole com a colocação simultânea de implantes na região anterior de mandíbula.