Tilted implants and prototyping: A security option for improving the anchorage in atrophic maxilla

Rehabilitating atrophic maxilla poses many challenges. Reconstructive techniques that require sinus grafting are viable and acceptable; however, these techniques also are considered to be expensive, invasive, and time-consuming. Tilted implants anchored in distal areas using available bone have been reported as a less invasive and highly predictable treatment option. This article presents a case involving implant anchorage via tilted implants as an alternative technique to bone grafting procedures. Copyright © 2013 by the Academy of General Dentistry.

Stress analysis in oral obturator prostheses over parallel and tilted implants: photoelastic imaging

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

All-on-four concept and immediate loading for simultaneous rehabilitation of the atrophic maxilla and mandible with conventional and zygomatic implants

We report the simultaneous rehabilitation of an edentulous patient with a hybrid (zygomatic and conventional implants) all-on-four implant-supported prosthesis for the maxilla and a standard (conventional implants) all-on-four implant-supported prosthesis for the mandible. The transfer impression was made with a multifunctional guide and the upper and lower prostheses were placed 24 h postoperatively. Clinical and radiographic examinations showed no infection or bony resorption 2 years later. Simultaneous maxillary and mandibular rehabilitation with all-on-four immediate loading is a viable, fast and effective option for edentulous patients. (C) 2009 Published by Elsevier Ltd on behalf of The British Association of Oral and Maxillofacial Surgeons.

Dynamic UCLA for single tilted implant in an aesthetic region

The aim of this paper was to present a rehabilitation of a patient with a dynamic universal castable long abutment (UCLA) for a single tilted implant in the anterior maxillary area. A 57-year-old male patient attended the dentistry college clinic complaining of a vertical fracture of a residual root of the dental element 22. The tooth extraction was indicated for the implant installation. Due to the socket buccal wall thickness, the implant was installed with an inclination to the palate. It was done in a two-stage surgical protocol, and an external hexagon implant (3.75×11.5mm) was placed. After a six-month healing period to correct the implant position, a dynamic UCLA was set in place, rectifying the implant emergence profile at 20°. The ceramic structure fitting was performed and, after the patient's consent, the prosthesis was finalized and installed. After a follow-up period of twenty months, no complications were observed. The installation of tilted implants with a dynamic UCLA may be a viable option, faster and less invasive than bone grafts.

Análise fotoelástica de tensões em próteses obturadoras palatinas implantorretidas, sobre implantes paralelos ou inclinados, associados a diferentes tipos de sistemas de retenção

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Avaliação da distribuição das tensões em prótese do tipo “All on Four”: estudo pelo método dos elementos finitos tridimensionais

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Análise das microdeformações geradas ao redor de implantes de hexágono externo sob a aplicação de cargas verticais em pilares microunit retos e angulados

Pós-graduação em Odontologia Restauradora - ICT

Análise das tensões em próteses implantossuportadas esplintadas, variando o tipo de conexão protética e a inclinação do implante: estudo pelo método dos elementos finitos tridimensionais não linear

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Tilted and Short Implants Supporting Fixed Prosthesis in an Atrophic Maxilla: A 3D-FEA Biomechanical Evaluation

Purpose: This study compared the biomechanical behavior of tilted long implant and vertical short implants to support fixed prosthesis in an atrophic maxilla. Materials and Methods: The maxilla model was built based on a tomographic image of the patient. Implant models were based on micro-computer tomography imaging of implants. The different configurations considered were M4S, four vertical anterior implants; M4T, two mesial vertical implants and two distal tilted (45°) implants in the anterior region of the maxilla; and M6S, four vertical anterior implants and two vertical posterior implants. Numerical simulation was carried out under bilateral 150N loads applied in the cantilever region in axial (L1) and oblique (45°) (L2) direction. Bone was analyzed using the maximum and minimum principal stress (σmax and σmin), and von Mises stress (σvM) assessments. Implants were analyzed using the σvM. Results: The higher σmax was observed at: M4T, followed by M6S/L1, M6S/L2, M4S/L2, and M4S/L1 and the higher σvM: M4T/L1, M4T/L2 and M4S/L2, M6S/L2, M4S/L1, and M6S/L1. Conclusions: The presence of distal tilted (all-on-four) and distal short implants (all-on-six) resulted in higher stresses in both situations in the maxillary bone in comparison to the presence of vertical implants (all-on-four). © 2013 Wiley Periodicals, Inc.

Influence of Tapered and External Hexagon Connections on Bone Stresses Around Tilted Dental Implants: Three-Dimensional Finite Element Method With Statistical Analysis

Background: The purpose of this study is to analyze the tension distribution on bone tissue around implants with different angulations (0 degrees, 17 degrees, and 30 degrees) and connections (external hexagon and tapered) through the use of three-dimensional finite element and statistical analyses.Methods: Twelve different configurations of three-dimensional finite element models, including three inclinations of the implants (0 degrees, 17 degrees, and 30 degrees), two connections (an external hexagon and a tapered), and two load applications (axial and oblique), were simulated. The maximum principal stress values for cortical bone were measured at the mesial, distal, buccal, and lingual regions around the implant for each analyzed situation, totaling 48 groups. Loads of 200 and 100 N were applied at the occlusal surface in the axial and oblique directions, respectively. Maximum principal stress values were measured at the bone crest and statistically analyzed using analysis of variance. Stress patterns in the bone tissue around the implant were analyzed qualitatively.Results: The results demonstrated that under the oblique loading process, the external hexagon connection showed significantly higher stress concentrations in the bone tissue (P < 0.05) compared with the tapered connection. Moreover, the buccal and mesial regions of the cortical bone concentrated significantly higher stress (P < 0.005) to the external hexagon implant type. Under the oblique loading direction, the increased external hexagon implant angulation induced a significantly higher stress concentration (P = 0.045).Conclusions: The study results show that: 1) the oblique load was more damaging to bone tissue, mainly when associated with external hexagon implants; and 2) there was a higher stress concentration on the buccal region in comparison to all other regions under oblique load.

Posterior partially edentulous jaws, planning a rehabilitation with dental implants

To discuss important characteristics of the use of dental implants in posterior quadrants and the rehabilitation planning. An electronic search of English articles was conducted on MEDLINE (PubMed) from 1990 up to the period of March 2014. The key terms were dental implants and posterior jaws, dental implants/treatment planning and posterior maxilla, and dental implants/treatment planning and posterior mandible. No exclusion criteria were used for the initial search. Clinical trials, randomized and non randomized studies, classical and comparative studies, multicenter studies, in vitro and in vivo studies, case reports, longitudinal studies and reviews of the literature were included in this review. One hundred and fifty-two articles met the inclusion criteria of treatment planning of dental implants in posterior jaw and were read in their entirety. The selected articles were categorized with respect to their context on space for restoration, anatomic considerations (bone quantity and density), radiographic techniques, implant selection (number, position, diameter and surface), tilted and pterygoid implants, short implants, occlusal considerations, and success rates of implants placed in the posterior region. The results derived from the review process were described under several different topic headings to give readers a clear overview of the literature. In general, it was observed that the use of dental implants in posterior region requires a careful treatment plan. It is important that the practitioner has knowledge about the theme to evaluate the treatment parameters. The use of implants to restore the posterior arch presents many challenges and requires a detailed treatment planning.

Annual evolution of global, direct and diffuse radiation and fractions in tilted surfaces

Avaliou-se a evolução anual das componentes global, direta e difusa da radiação solar incidente em superfícies inclinadas a 12,85; 22,85 e 32,85º, com face voltada ao Norte, em Botucatu-SP. Foram obtidas frações radiométricas para cada componente da radiação nas superfícies supracitadas, através de razões com a radiação global e a do topo da atmosfera. A sazonalidade foi avaliada através das médias mensais dos valores diários. As medidas ocorreram entre 04/1998 e 07/2001, em 22,85º; 08/2001 e 02/2003, em 12,85º; e de 03/2003 a 12/2007, em 32,85º, com medidas concomitantes no plano horizontal (referência). Os níveis das radiações global e direta nos planos inclinados foram inferiores no período de verão e superiores entre os equinócios, quando comparadas ao plano horizontal. A radiação difusa nas superfícies inclinadas foi inferior na maioria dos meses, com perdas de até 65%. Ocorreu uma tendência de aumento das diferenças entre as superfícies horizontal e inclinada com o incremento do ângulo em todas as componentes e frações da radiação incidente. A evolução anual das precipitações pluviométricas e da razão de nebulosidade afetou diretamente a transmissividade atmosférica das componentes direta e difusa na região.

Extraocular muscle fixation to porous polyethylene orbital implants using 2-octyl-cyanoacrylate

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

The influence of external ultrasound on the histologic architecture of the organic capsule around smooth silicone implants: Experimental study in rats

Background Capsular contracture is the main complication related to breast silicone implants, and its prevention remains a medical challenge. The authors present experimental research examining the effect of external ultrasound on the formation and contracture of peri-implant capsules.Methods In this study, 42 male Wistar rats had a 2-mm smooth surface implant placed in a dorsal submuscular pocket. They then were separated into ultrasound'' and control'' groups that received repeated external applications either with or without the ultrasound power on. Ultrasound applications were given three times a week for a period of 90 days. After that, both groups were housed under the same conditions with no application scheduled. Five animals of each group, killed at 30, 60, 90, and 180 days, had their implants removed along with the capsule, which received a special histologic preparation via annular sectioning that provided wide circumferential observation of the capsular tissue. Sections were stained with hematoxylin/eosin stain, Masson's trichrome stain, and Pricrosirius Red stain for regular microscopic evaluation under normal and polarized light.Results Histologic data showed that capsules from the ultrasound and control groups had statistically significant differences. Ultrasound application developed a capsular architecture similar to that shown within textured silicone implants, and its effect had an early definition with subsequent stabilization.Conclusion The authors conclude that early and repeated external ultrasound application enhances the thickness, cellular count, and vascularity of smooth silicone capsular tissue, whereas it diminishes the pattern of parallel orientation of collagen fibers.

Gel and porous polyethylene implants for anophthalmic cavity reconstruction-evaluation using the B scan ultrasound

AIM: To evaluate the host response of the gel and porous polyethylene implants in anophthalmic cavities using the B scan ultrasound.METHODS: Thirty-six white rabbits underwent unilateral enucleation with placement of gel or porous polyethylene spheres implants. The animals were submitted to clinical examination weekly and to ultrasound evaluation on 30, 60 and 90 days after surgery.RESULTS: All rabbits with gel polyethylene spheres, except one, showed implant extrusion probably because the gel spheres have hydrated and increased in volume. The B ultrasound of the gel polyethylene implant did not show vessels inside during the following period. Five animals (27.8%) with porous polyethylene spheres presented implant extrusion after 30 days of surgery. According to B ultrasound, the porous polyethylene implant showed irregular and heterogeneous architecture and reflective peaks similar to vascularized tissues.CONCLUSION: More studies are required to determine the ideal volume of gel polyethylene implant necessary to correct the diminished orbital content in the anophthalmic cavity. The B ultrasound effectiveness showed in this study for anophthalmic socket implants evaluation provides useful information for further in vivo studies and might substitute expensive methods of implants vascularization evaluation,