Overdenture sobre raízes: uma alternativa na reabilitação protética de pacientes parcialmente dentados / Root-retained overdentures: prosthodontic rehabilitation alternative to partially dentate patients

O propósito do estudo foi realizar uma revisão de literatura a respeito do aproveitamento de raízes remanescentes para retenção de overdenture, as indicações dessa modalidade protética, sua longevidade e benefícios como alternativa reabilitadora viável. Foram consultadas bases de dados científicas, pesquisas diretas através de buscadores virtuais e em bibliotecas físicas, sem período cronológico estabelecido, tendo como descritores: ôsobredentaduraõ, ômanutenção de raízesõ, ôdentadura retida por dentesõ, ôoverdentureõ, ôroot maintainingõ e ôtooth-retained dentureõ. Baseada na revisão de literatura, concluiu-se que a overdenture retida por dentes remanescentes é mais estável e retentiva quando comparada a próteses removíveis convencionais, leva à manutenção dos estímulos proprioceptores, impede a reabsorção óssea adjacente, proporciona adequada eficiência mastigatória, restabelece o bem-estar social e psíquico do paciente e é um tratamento de baixo custo, fácil manutenção e evita procedimentos extensos e invasivos...

The purpose of the study was to review the literature on using remaining dental roots for overdenture retention, indications for these prosthodontics mode, its longevity and benefits as a viable rehabilitation alternative. For this literature review, scientific databases were perused and direct Internet searches were done, with no time period established, having as descriptors: ôoverdentureõ, ôroot maintainingõ and ôtooth-retained dentureõ. Based on the literature review, it was concluded that overdentures retained by remaining teeth are more stable and retentive when compared to conventional removable prosthesis, it leads to the proprioception maintaining, continued preservation of the bone around the remaining teeth, provides appropriate chewing efficiency, reestablishes the patientÆs social e psychic comfort, and it is a low cost, easy maintenance treatment that avoid extensive procedures...

Influence of different cantilever extensions and glass or polyaramid reinforcement fibers on fracture strength of implant-supported temporary fixed prosthesis

In long-term oral rehabilitation treatments, resistance of provisional crowns is a very important factor, especially in cases of an extensive edentulous distal space. The aim of this laboratorial study was to evaluate an acrylic resin cantilever-type prosthesis regarding the flexural strength of its in-balance portion as a function of its extension variation and reinforcement by two types of fibers (glass and polyaramid), considering that literature is not conclusive on this subject. Each specimen was composed by 3 total crowns at its mesial portion, each one attached to an implant component (abutment), while the distal portion (cantilever) had two crowns. Each specimen was constructed by injecting acrylic resin into a two-part silicone matrix placed on a metallic base. In each specimen, the crowns were fabricated with either acrylic resin (control group) or acrylic resin reinforced by glass (Fibrante, Angelus) or polyaramide (Kevlar 49, Du Pont) fibers. Compression load was applied on the cantilever, in a point located 7, 14 or 21 mm from the distal surface of the nearest crown with abutment, to simulate different extensions. The specimen was fixed on the metallic base and the force was applied until fracture in a universal test machine. Each one of the 9 sub-groups was composed by 10 specimens. Flexural strength means (in kgf) for the distances of 7, 14 and 21 mm were, respectively, 28.07, 8.27 and 6.39 for control group, 31.89, 9.18 and 5.16 for Kevlar 49 and 30.90, 9.31 and 6.86 for Fibrante. Data analysis ANOVA showed statistically significant difference (p<0.05) only regarding cantilever extension. Tukey’s test detected significantly higher flexural strength for the 7 mm-distance, followed by 14 and 21 mm. Fracture was complete only on specimens of non-reinforced groups.

Influence of different catilever extensions and glass or polyamaramid reinforcement fibers on fracture strength of implant-supported temporary

In long-term oral rehabilitation treatments, resistance of provisional crowns is a very important factor, especially in cases of an extensive edentulous distal space. The aim of this laboratorial study was to evaluate an acrylic resin cantilever-type prosthesis regarding the flexural strength of its in-balance portion as a function of its extension variation and reinforcement by two types of fibers (glass and polyaramid), considering that literature is not conclusive on this subject. Each specimen was composed by 3 total crowns at its mesial portion, each one attached to an implant component (abutment), while the distal portion (cantilever) had two crowns. Each specimen was constructed by injecting acrylic resin into a two-part silicone matrix placed on a metallic base. In each specimen, the crowns were fabricated with either acrylic resin (control group) or acrylic resin reinforced by glass (Fibrante, Angelus) or polyaramide (Kevlar 49, Du Pont) fibers. Compression load was applied on the cantilever, in a point located 7, 14 or 21 mm from the distal surface of the nearest crown with abutment, to simulate different extensions. The specimen was fixed on the metallic base and the force was applied until fracture in a universal test machine. Each one of the 9 sub-groups was composed by 10 specimens. Flexural strength means (in kgf) for the distances of 7, 14 and 21 mm were, respectively, 28.07, 8.27 and 6.39 for control group, 31.89, 9.18 and 5.16 for Kevlar 49 and 30.90, 9.31 and 6.86 for Fibrante. Data analysis ANOVA showed statistically significant difference (p<0.05) only regarding cantilever extension. Tukey's test detected significantly higher flexural strength for the 7 mm-distance, followed by 14 and 21 mm. Fracture was complete only on specimens of non-reinforced groups.

Avaliaçäo da dureza Rockwell (30T) de 29 resinas compostas / Rockwell hardness (30T) of 20 composite resins

A dureza é um dos importantes fatores a ser observado dentre as características dos materiais, sendo provavelmente indicativa de algumas outras propriedades mecânicas, inclusive para as resinas compostas. Foi analisada a dureza Rockwell 30T de 29 compósitos, confeccionando-se 3 corpos-de-prova para cada material. Após fotopolimerizaçäo por 80 segundos, aguardava-se mais 5 minutos e determinava-se a dureza (inicial); os espécimes eram entäo armazenados em água desionizada, a 37§C, durante 168 horas, quando nova leitura da dureza (final) era realizada. Estatisticamente, todas as resinas mostraram aumento de dureza, da mediçäo imediata para a com 168 horas; a resina Filtek Z-100 isoladamente apresentou o maior valor de dureza inicial; quando da dureza final, ela também apresentou o maior valor, agora acompanhada pela Filtek P-60; a de pior desempenho foi a Helioprogress, em ambas as idades