Retenção de grampos cirucenferenciais associados a retentores intra-radiculares com encaixe era utilizados em overdentures parciais removíveis

• Autor(a) principal: SOUZA, José Everaldo de Aquino
• Data de Publicação: 2008
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UFG
• dARK ID: ark:/38995/001300000bt43
• Texto Completo: http://repositorio.bc.ufg.br/tede/handle/tde/1382
• topic: Prótese Parcial Removível; Grampos Dentários; Encaixe de Precisão de Dentadura; Removable Partial Denture; Dental Clasps; Denture Precision Attachment; CNPQ::CIENCIAS DA SAUDE::ODONTOLOGIA::CLINICA ODONTOLOGICA

The overdentures can be defined as total or partial removable dentures that cover root or osseo integrated implants rehabilitating the whole dentition. The mechanical retention in the removable partial overdentures (RPOs) is obtained through the use of cast clasps and attachments. This biomechanical principle has a great importance, since is inwardly associated with long term behavior and clinical performance of prosthesis and consequently, with comfort and satisfaction of the patients. So, the aim of this study was to assess the retention of metallic framework with simple circumferential claps associated intraradicular retainer with attachment type ERA (Extra coronal Resilient Attachment, Sterngold Implamed, Attleboro, EUA) in function of the metals based cobalt-chromium alloy (Co-Cr), titanium commercially pure (Ti cp) and nickel-chromium with titanium alloy (Ni-Cr with Ti), of the retentive undercuts of 0,25mm and 0,75mm and in function of the time of use in each simulated period (initial, 6 months, 1, 2, 3, 4 e 5 years). Through of metallic matrices representing a partially edentulous mandibular right hemi-arch segment constituted by the crown of the first molar, root of the inferior canine and with the absent of the premolars, were made 60 metallic frameworks being obtained 03 groups of each metal and subgroups representative of the 0,25mm and 0,75mm retentive undercuts of the circumferential clasp (totalizing 10 samples in each subgroup). Acrylic denture bases were constructed on the denture space and on the canine root that anchored the attachments and these received retentive capsules in the gray color of the system. Previously the mechanic tests, radiographic exams of the Ti cp frameworks were realized with the aim of detecting possible casting defects that could avert the posterior use. Next, the samples were mechanically tested simulating the insertion and removal of the framework using the testing apparatus designed at the Ribeirão Preto School of Dentistry (Testing apparatus, São Paulo University, Ribeirão Preto, Brazil), representing 5 years of simulated used. To simulate the intraoral conditions and realize the tests, a gadget fulfilled with artificial saliva was adapted in the testing apparatus. The retentive force data were recorded and submitted linear regression analysis and analysis of variance (ANOVA) to gauge a presence or not of significant differences and applied the Tukey complementary test 5% to comparison of the differences between the groups and subgroups. The groups of Ni-Cr with Ti and Co-Cr samples obtained most retentive mean with significant differences to group of Ti cp samples that obtained least retentive mean in every periods of time analyzed. To groups Ni-Cr with Ti and Co-Cr samples there was not significant difference of retention between the times analyzed free-standing of retentive undercuts (p > 0,05). In the group Ti cp samples there was significant difference of retention between the times analyzed just to subgroup samples with 0,75mm undercuts (p < 0,05). The Ni-Cr with Ti and Co-Cr samples with 0,75mm undercuts presented the most retentive mean and the Co-Cr samples with 0,25mm undercuts presented retention mean intermediate between biomechanical design in every periods of time analyzed. The Ti cp samples with 0,25mm undercuts presented the least retentive mean until second year of the analyze and the Ti cp samples with 0,75mm undercuts presented the least retentive mean of third until fifth year of the analyse. The circumferential claps casting in Ti cp used in 0,75mm undercuts have potential risk of fractures, mainly after the 2o year of use