Seven-Year Follow-up of Full-Arch Prostheses Supported by Four Implants: A Prospective Study.

PURPOSE: To evaluate biologic and prosthetic outcomes of implant-supported mandibular full-arch fixed prostheses treated with the All-on-4 treatment concept after 7 years. MATERIALS AND METHODS: Patients were selected to receive full-arch fixed immediate prostheses supported by four implants up to 72 hours after surgery. The following biologic aspects were evaluated: Plaque Index (PI) and Bleeding Index (BI), implant stability by resonance frequency, and marginal bone loss (MBL) measured with the aid of periapical radiographs. The prosthetic complications evaluated were related to screw loosening, framework or acrylic teeth fractures, or fractures of implants. The means of implant stability and MBL were subjected to analysis of variance and the Tukey test (P < .05). For PI and BI, the Friedmann test was used (P < .05). RESULTS: Sixteen patients (12 women and 4 men; mean age: 59.1 years) received 64 implants, and in all patients, two implants were positioned axially at the incisor region and two distally tilted implants at the region of the second premolars or molars. Patients were evaluated immediately after surgery and at 1, 2, and 7 years. Fifteen patients attended the recall after 2 years; one patient could not attend the scheduled follow-up visit and was excluded from the sample. In the 7-year evaluation, the sample size decreased to 12 patients; one could not attend because of a severe disease, and two were deceased. The cumulative implant survival rate was 100%. There was a significant (P < .0162) decrease in PI at the 1- and 7-year evaluations (71.87% and 47.92%, respectively), while the BI was the same at 1 and 7 years (43.75%). There was no statistical difference in MBL (P = .12) and implant stability (P = .48) between axial and tilted implants (P = .48). The survival rate of prostheses was 100%. The following technical complications were observed: tooth fracture occurred in one patient (6.25%); loosening of prosthetic screws and abutments were observed in three patients (18.75%); after 5 years, three patients (18.75%) had changed the denture acrylic teeth because of the replacement of the removable total maxillary prostheses with fixed implant prostheses. CONCLUSION: For the 12 patients who attended the recall after 7 years, implant loss was not found, the implant stability was high, MBL was low, and prosthetic complications were easily solved. Thus, it can be concluded that rehabilitation with implant-supported mandibular full-arch fixed prostheses with four implants has proved to be a treatment with a high survival rate.

Enxerto ósseo onlay autógeno de área doadora intraoral: relato de caso / Autogenous onlay bone grafts from an intraoral donor site: case report

A reconstrução óssea com blocos de enxertos tem sido utilizada na Implantodontia com o propósito de possibilitar a instalação de implantes quando o tecido de suporte é insuficiente ou não possibilitaria o posicionamento do implante na sua forma ideal. A técnica de enxertia realizada com o uso de osso autógeno é considerada a primeira opção de tratamento por esse material possuir características mais próximas do ideal como osteogenicidade e biocompatibilidade. Áreas doadoras intrabucais demonstram fornecer tecido suficiente, com menor morbidade e custo comparadas as áreas extrabucais. O presente relato de caso, associado à revisão de literatura, tem como objetivo analisar e discutir os diferentes aspectos de um tratamento com utilização de enxerto autógeno como: definição dos parâmetros que levam a opção pelo tratamento com enxerto ósseo, limitações do tratamento, escolha da área doadora, descrição da técnica e escolha pela colocação dos implantes simultaneamente ou não ao enxerto

Reconstruction with bone block grafts has been used in Implantology in order to permit the installation of implants when the alveolar ridge support is insufficient or can’t provide the positioning of the implant in its ideal form. The grafting technique accomplished with the use of autogenous bone is considered the first choice of treatment because this material has characteristics closer to ideal such as osteogenic potential and biocompatibility. Intraoral donor sites have proved to provide enough quantity of bone, with lower morbidity and cost compared to extraoral areas. The present case report, associated with a literature review, aims to analyze and discuss the different aspects of treatment using autograft such as: defining the parameters that lead to choosing treatment with bone graft, limitations of treatment, choice of donor area, description of technique and choice for placing implants simultaneously or not to graft

Utilização de implante estreito de TiZr em região de alta incidência de carga: relato de caso / The use of TiZr narrow implant in high impact load region: case report

Implantes estreitos de titânio surgiram na Implantodontia com a indicação clássica de serem utilizados para substituição de incisivos laterais superiores, incisivos inferiores, espaços edêntulos pequenos e com baixa incidência de carga mastigatória. Porém, na literatura encontra-se relatos de falhas mecânicas e biológica desses implantes, quando utilizados em situações de maior incidência de carga mastigatória, como em caninos e molares. Para permitir uma ampliação das indicações dos implantes de diâmetro reduzido, uma nova liga foi desenvolvida com objetivo de compensar as deficiências relatada. Os novos implantes estreitos são confeccionados a partir de uma liga de titânio e zircônia (TiZr), com 13-17% de zircônia em sua composição e possuem 3,3 mm de diâmetro. A nova liga apresenta maior resistência do que os implantes de titânio grau IV e melhor biocompatibilidade que as ligas de Ti-6Al-4V. Assim, vem sendo uma alternativa viável para ampliar as indicações clássicas dos implantes estreitos convencionais. No caso apresentado, o implante estreito de TiZr foi utilizado em região de segundo molar inferior como pilar de uma prótese fixa de 4 elementos, a fim de permitir a reabilitação de uma paciente que possuía perda óssea vertical severa, necessitando o implante tangenciar do nervo alveolar inferior. O controle foi feito durante 15 meses sem apresentar qualquer complicação, sendo assim, concluiu-se que os implantes estreitos de TiZr podem ser utilizados em espaços edêntulos reduzidos e táboa óssea fina, independente do dente a ser substituído

Narrow titanium implants came with the classic indication for use for replacement of maxillary lateral incisors, lower incisors and small edentulous spaces with low incidence of masticatory load. However, the literature reports biological and mechanical failures of these implants when used in situations of higher incidence of masticatory load, such as canines and molars. To amplify the indication of small diameter implants, a new alloy was developed in order to compensate for the deficiencies reported. The new narrow implants are made from an alloy of titanium and zirconium (TiZr) with 13-17% of zirconia in their composition and have 3.3 mm diameter. The new alloy has higher resistance than the titanium implants grade IV and better biocompatibility than the alloy Ti-V-6Al4, therefore it has being a viable alternative to broaden the classical indications of narrow conventional implants. In the case reported, the Strait of TiZr implant was used in the region of the second molar as an abutment for a fixed prosthesis in the four elements in order to allow the rehabilitation of a patient with severe vertical bone loss requiring that the implant was tangent to lower alveolar nerve. The control was carried out for 15 months without any complications, and therefore, it was concluded that the narrow TiZr implants can be used in reduced edentulous spaces and thin bone, independent of the tooth to be replaced