Dental implant fractures: aetiology, treatment and case report

Purpose: This study aimed to investigate the etiology, clinical manifestations, and treatment options of dental implants fractures through a literature review and to relate a clinical report. Methods: A literature review was performed using the Medline database and this paper describes a case demonstrating the management of implant fracture. Twenty two articles were selected in the present literature review. Results: Nowadays the use of dental implants to rehabilitate completely and partially edentulous patients became the best treatment option; however, this treatment is suitable to failure. The fracture of implant body is a possible complication. The fracture of implant body is a late complication and is related to the failure in implant design or material, non-passive fitting of the prosthetic crown and overloading. Clinically, prosthesis instability and spontaneous bleeding are observed. Three options of treatment have been indicated: complete removal of implant fragment, maintenance of implant fragment, and surface preparation of the fragment with insertion of a new abutment. Conclusion: The literature indicates the complete removal of the fragment as the best treatment option.

Regeneração óssea guiada em implantodontia: relato de caso

Objective: The use of methods for tissue regeneration has been widely applied in Implantology, in clinical situations with disabilities or anatomical limitations that prevent the placement of osseointegrated dental implants. The evolution of the development of biomaterials revolutionized this therapeutic modality, facilitating the resolution of clinical cases with tissue deficiencies. Thus, this study aimed to describe a clinical case approaching the methods, techniques, and materials used in guided bone regeneration applied to Implantology. Case report: A clinical case of a patient who received a Morse taper dental implant (region 15) is described. The use of biomaterial and membrane on the buccal wall of the socket was required. After the osseointegration period, a reopening surgery was performed, and an immediate provisional implant was produced. After 2 months of follow-up, the final prosthesis was made involving other adjacent elements. Final considerations: The guided bone regeneration technique employed showed satisfactory performance. The patient was positive regarding esthetics and function. However, more controlled studies with longer follow-up period are needed for analyses of predictability

Esthetics in implant-supported prostheses: a literature review

Esthetics is important for success of implant-supported prostheses. This study aimed to review esthetics concepts for implant treatment. Research in the PubMed database included studies published from 1995 to 2010 with the keywords implant esthetics, implant-supported prostheses, and esthetics. Forty-five studies were evaluated regarding the presurgical planning, surgical phase, and temporary and final restoration phases. It was concluded that esthetics in implant-supported prostheses results from a multidisciplinary approach from planning until insertion of the final restoration.

Distal extension removable partial denture with resilient attachment connect to an anterior fixed implant-supported prosthesis: a clinical report

Background: Considering the limited qualitative and quantitative bone in the posterior arch, this modality of prosthetic treatment could provide a positive emotional factor reestablished by immovability of the anterior fixed implant-supported segment. Objective: This clinical report demonstrates the possibility of achieving positive results with a removable partial denture connected to an implant-supported fixed prosthesis associated to an extra resilient attachment. Clinical significance: In cases of posterior mandibular and maxilla atrophy added to the patients desire against the bone graft, this kind of prosthetic treatment has an important place as an alternative.

The influence of the alveolar ridge shape on the stress distribution in a free-end saddle removable partial denture supported by implant

The alveolar ridge shape plays an important role in predicting the demand on the support tooth and alveolar bone in the removable partial denture (RPD) treatment. However, these data are unclear when the RPD is associated with implants. This study evaluated the influence of the alveolar ridge shape on the stress distribution of a free-end saddle RPD partially supported by implant using 2-dimensioanl finite element analysis (FEA). Four mathematical models (M) of a mandibular hemiarch simulating various alveolar ridge shapes (1-distal desceding, 2- concave, 3-horizontal and 4-distal ascending) were built. Tooth 33 was placed as the abutment. Two RPDs, one supported by tooth and fibromucosa (MB) and other one supported by tooth and implant (MC) were simulated. MA was the control (no RPD). The load (50N) were applied simultaneously on each cusp. Appropriate boundary conditions were assigned on the border of alveolar bone. Ansys 10.0 software was used to calculate the stress fields and the von Mises equivalent stress criteria (σvM) was applied to analyze the results. The distal ascending shape showed the highest σvM for cortical and medullar bone. The alveolar ridge shape had little effect on changing the σvM based on the same prosthesis, mainly around the abutment tooth.

Reconstruction of maxillary ridge atrophy caused by dentoalveolar trauma, using autogenous block bone graft harvested from chin: a case report

Background Dentoalveolar trauma, especially when involving front teeth, negatively affect the patient’s life; in particular, tooth avulsion is a complex injury that affects multiple tissues, and no treatment option offers stable long-term outcomes. The aim of this study was to report a case of reconstruction of atrophic anterior alveolar ridge after tooth loss, performed with autograft harvested from the chin, and subsequent prosthetic rehabilitation with the use of an osseointegrated implant. Case report A 23-years-old Caucasian girl, presented an atrophic alveolar bone in the area of tooth 11, as a result of tooth resorption 10 years after a tooth reimplantation procedure. Reconstruction was performed with autogenous bone harvested from the chin. After 6-months healing period to allow autograft incorporation, a dental implant was inserted. After further 6- months, a screw-retained implant supported metal-ceramic prosthesis was fabricated. Results The prosthetic rehabilitation was successful, and after a follow-up period of 5 years, the achieved result was stable.Conclusion It can be concluded that the autogenous bone graft harvested from the chin, is a safe and effective option for alveolar ridge defects reconstruction, allowing a subsequent placement of a dental implant supporting a prosthetic restoration.

Effect of framework soldering on the deformation of implant abutments after framework seating

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

Effect of veneering material on the deformation suffered by implant-supported fixed prosthesis framework

The aim of this study was to evaluate the deformation suffered by cantilevered implant-supported fixed prostheses frameworks cast in silver-palladium alloy and coated with two occlusal veneering materials: acrylic resin or porcelain. Material and Methods: Two strain gauges were bonded to the inferior surface of the silver-palladium framework and two other were bonded to the occlusal surface of the prosthesis framework covered with ceramic and acrylic resin on each of its two halves. The framework was fixed to a metallic master model and a 35.2 N compression force was applied to the cantilever at 10, 15 and 20 mm from the most distal implant. The measurements of deformation by compression and tension were obtained. The statistical 2-way ANOVA test was used for individual analysis of the experiment variables and the Tukey test was used for the interrelation between all the variables (material and distance of force application). Results: The results showed that both variables had influence on the studied factors (deformation by compression and tension). Conclusion: The ceramic coating provided greater rigidity to the assembly and therefore less distortion compared with the uncoated framework and with the resin-coated framework. The cantilever arm length also influenced the prosthesis rigidity, causing higher deformation the farther the load was applied from the last implant.

EREMOPHYGUS BICOLOR (GUTIÉRREZ) (COLEOPTERA: SCARABAEIDAE: RUTELINAE: RUTELINI): A NEW TRIBAL AND GENERIC PLACEMENT FOR THE BOLIVIAN SCARAB PLATYCOELIA BICOLOR (GUTIÉRREZ) (ANOPLOGNATHINI)

Platycoelia bicolor (Gutiérrez) (Scarabaeidae: Rutelinae) is transferred from the tribe Anoplognathini, subtribe Platycoeliina, to the tribe Rutelini. Platycoelia bicolor is placed in the genus Eremophygus Ohaus and the taxonomic history of the species is discussed. The transfer creates a new combination, Eremophygus bicolor (Gutiérrez) and places the generic name Heterocallichloris Gutiérrez as a junior synonym of Eremophygus (new synonymy). Morphological characters that warrant the transfer are discussed. Se transfiere Platycoelia bicolor (Gutiérrez) (Scarabaeidae: Rutelinae) de la tribu Anoplognathini, subtribe Platycoeliina, a la tribu Rutelini. Se transfiere Platycoelia bicolor al género Eremophygus Ohaus y se discute su historia taxonómica. La transferencia crea una nueva combinación, Eremophygus bicolor (Gutiérrez) y ubica al nombre genérico Heterocallichloris Gutiérrez como un sinónimo junior de Eremophygus. Se discuten los caracteres morfológicos que justifican la transferencia.

An algorithm for the strip packing problem using collision free region and exact fitting placement

The irregular shape packing problem is approached. The container has a fixed width and an open dimension to be minimized. The proposed algorithm constructively creates the solution using an ordered list of items and a placement heuristic. Simulated annealing is the adopted metaheuristic to solve the optimization problem. A two-level algorithm is used to minimize the open dimension of the container. To ensure feasible layouts, the concept of collision free region is used. A collision free region represents all possible translations for an item to be placed and may be degenerated. For a moving item, the proposed placement heuristic detects the presence of exact fits (when the item is fully constrained by its surroundings) and exact slides (when the item position is constrained in all but one direction). The relevance of these positions is analyzed and a new placement heuristic is proposed. Computational comparisons on benchmark problems show that the proposed algorithm generated highly competitive solutions. Moreover, our algorithm updated some best known results. (C) 2012 Elsevier Ltd. All rights reserved.

Leakage of Saliva Through the Implant-Abutment Interface: In Vitro Evaluation of Three Different Implant Connections Under Unloaded and Loaded Conditions

Purpose: Bacterial leakage along the implant-abutment interface, with consequent species harboring the inner parts of two-part dental implant systems, has been reported in the literature. The aim of this in vitro study was to evaluate bacterial leakage from human saliva to the internal part of the implants along the implant-abutment interface under loaded and unloaded conditions using DNA Checkerboard. Materials and Methods: Sixty denial implants-20 each of external-hexagon, internal-hexagon, and Morse cone-connection designs-and their conical abutments were used in this study. Each group was subdivided into two groups of 10 loaded and 10 unloaded implants. The assemblies were immersed in human saliva and either (1) loaded with 500,000 cycles at 120 N (experimental group) or (2) incubated in static conditions for 7 days at 35 degrees C (unloaded control group). Results: Microorganisms were found in the internal surfaces of all types of connections. The Morse cone connection presented the lowest count of microorganisms in both the unloaded and loaded groups. Loaded implants presented with higher counts of microorganisms than unloaded implants for external- and internal-hex connections. Conclusion: Bacterial species from human saliva may penetrate along the implant-abutment interface under both unloaded and loaded conditions for all connections evaluated. Morse cone-connection implants showed the lowest counts of microorganisms for both conditions. External- and internal-hex implants showed a higher incidence of bacteria and higher bacterial counts after simulated loading. INT J ORAL MAXILLOFAC IMPLANTS 2012;27:551-560.

Efficient Placement of Fault Indicators in an Actual Distribution System Using Evolutionary Computing

This paper proposes an evolutionary computing strategy to solve the problem of fault indicator (FI) placement in primary distribution feeders. More specifically, a genetic algorithm (GA) is employed to search for an efficient configuration of FIs, located at the best positions on the main feeder of a real-life distribution system. Thus, the problem is modeled as one of optimization, aimed at improving the distribution reliability indices, while, at the same time, finding the least expensive solution. Based on actual data, the results confirm the efficiency of the GA approach to the FI placement problem.

Programming peculiarities in two cochlear implant users with superficial siderosis of the central nervous system

To report the audiological outcomes of cochlear implantation in two patients with severe to profound sensorineural hearing loss secondary to superficial siderosis of the CNS and discuss some programming peculiarities that were found in these cases. Retrospective review. Data concerning clinical presentation, diagnosis and audiological assessment pre- and post-implantation were collected of two patients with superficial siderosis of the CNS. Both patients showed good hearing thresholds but variable speech perception outcomes. One patient did not achieve open-set speech recognition, but the other achieved 70% speech recognition in quiet. Electrical compound action potentials could not be elicited in either patient. Map parameters showed the need for increased charge. Electrode impedances showed high longitudinal variability. The implants were fairly beneficial in restoring hearing and improving communication abilities although many reprogramming sessions have been required. The hurdle in programming was the need of frequent adjustments due to the physiologic variations in electrical discharges and neural conduction, besides the changes in the impedances. Patients diagnosed with superficial siderosis may achieve limited results in speech perception scores due to both cochlear and retrocochlear reasons. Careful counseling about the results must be given to the patients and their families before the cochlear implantation indication.

Bacterial leakage along the implant-abutment interface: culture and DNA Checkerboard hybridization analyses

Objective Bacterial species have been found harboring the internal surface of dental implants as consequence of their failed connections. The aim of the present study was to compare the detection frequency of bacterial leakage from human saliva through the implantabutment interface, under non-loading conditions, using either DNA Checkerboard or culture method. Materials and methods Thirty dental implants with hexagonal platforms were connected to pre-machined abutments according to the manufacturers specifications. The assemblies were individually incubated in human saliva under anaerobic conditions for 7 similar to days at 37 degrees C. Afterward, contents from the inner parts of the implants were collected and evaluated with either DNA Checkerboard (s similar to=similar to 15) or culture (n similar to=similar to 15). Subsequently, identification and quantitation of bacterial species from saliva and implants were carried out for the group evaluated with the DNA Checkerboard method. Results Both DNA Checkerboard and culture showed positive signals of bacterial leakage in 6 of the 15 evaluated samples. Capnocytophaga gingivalis and Streptococcus mutans were the most frequently detected species harboring the internal surface of the implants followed by Veillonella parvula. Conclusion Occurrence of bacterial leakage along the implantabutment interface is comparably detected with both DNA Checkerboard hybridization and conventional culture methods.

Measurement of buccal bone volume of dental implants by means of cone-beam computed tomography

Purpose: The aim of this study was to evaluate the accuracy of cone-beam computed tomography (CBCT) for measuring the buccal bone volume around dental implants. Materials and methods: Three to six implants were inserted into the anterior maxilla of eight skulls, depending on the availability of bone, and after this, the CBCT was performed. By means of CBCT image, measurements of the bone wall at three points of the implant were obtained, analyzed and compared with those obtained in the plaster skull casting. Results: The results showed that for the three points of the implants, no statistically significant difference in the measurements was obtained from the plaster model and CBCT images. Conclusions: CBCT can be a useful tool for assessing buccal bone volume along the implant. To cite this article:?Shiratori LN, Marotti J, Yamanouchi J, Chilvarquer I, Contin I, Tortamano-Neto P. Measurement of buccal bone volume of dental implants by means of cone-beam computed tomography.?Clin. Oral Impl. Res. 23, 2012; 797804.?doi: 10.1111/j.1600-0501.2011.02207.x