1.The selection criteria of temporary or permanent luting agents in implant-supported prostheses: in vitro study.
Angel ALVAREZ-ARENAL ; Ignacio GONZALEZ-GONZALEZ ; Hector DELLANOS-LANCHARES ; Aritza BRIZUELA-VELASCO ; Joseba ELLACURIA-ECHEBARRIA
The Journal of Advanced Prosthodontics 2016;8(2):144-149
PURPOSE: The use of temporary or permanent cements in fixed implant-supported prostheses is under discussion. The objective was to compare the retentiveness of one temporary and two permanent cements after cyclic compressive loading. MATERIALS AND METHODS: The working model was five solid abutments screwed to five implant analogs. Thirty Cr-Ni alloy copings were randomized and cemented to the abutments with one temporary (resin urethane-based) or two permanent (resin-modified glass ionomer, resin-composite) cements. The retention strength was measured twice: once after the copings were cemented and again after a compressive cyclic loading of 100 N at 0.72 Hz (100,000 cycles). RESULTS: Before loading, the retention strength of resin composite was 75% higher than the resin-modified glass ionomer and 2.5 times higher than resin urethane-based cement. After loading, the retentiveness of the three cements decreased in a non-uniform manner. The greatest percentage of retention loss was shown by the temporary cement and the lowest by the permanent resin composite. However, the two permanent cements consistently show high retention values. CONCLUSION: The higher the initial retention of each cement, the lower the percentage of retention loss after compressive cyclic loading. After loading, the resin urethane-based cement was the most favourable cement for retrieving the crowns and resin composite was the most favourable cement to keep them in place.
Alloys
;
Crowns
;
Dental Cements*
;
Glass
;
Patient Selection*
;
Prostheses and Implants*
2.Effect of implant- and occlusal load location on stress distribution in Locator attachments of mandibular overdenture. A finite element study.
Angel ALVAREZ-ARENAL ; Ignacio GONZALEZ-GONZALEZ ; Hector DELLANOS-LANCHARES ; Elena MARTIN-FERNANDEZ ; Aritza BRIZUELA-VELASCO ; Joseba ELLACURIA-ECHEBARRIA
The Journal of Advanced Prosthodontics 2017;9(5):371-380
PURPOSE: The aim of this study is to evaluate and compare the stress distribution in Locator attachments in mandibular two-implant overdentures according to implant locations and different loading conditions. MATERIALS AND METHODS: Four three-dimensional finite element models were created, simulating two osseointegrated implants in the mandible to support two Locator attachments and an overdenture. The models simulated an overdenture with implants located in the position of the level of lateral incisors, canines, second premolars, and crossed implant. A 150 N vertical unilateral and bilateral load was applied at different locations and 40 N was also applied when combined with anterior load at the midline. Data for von Mises stresses in the abutment (matrix) of the attachment and the plastic insert (patrix) of the attachment were produced numerically, color-coded, and compared between the models for attachments and loading conditions. RESULTS: Regardless of the load, the greatest stress values were recorded in the overdenture attachments with implants at lateral incisor locations. In all models and load conditions, the attachment abutment (matrix) withstood a much greater stress than the insert plastic (patrix). Regardless of the model, when a unilateral load was applied, the load side Locator attachments recorded a much higher stress compared to the contralateral side. However, with load bilateral posterior alone or combined at midline load, the stress distribution was more symmetrical. The stress is distributed primarily in the occlusal and lateral surface of the insert plastic patrix and threadless area of the abutment (matrix). CONCLUSION: The overdenture model with lateral incisor level implants is the worst design in terms of biomechanical environment for the attachment components. The bilateral load in general favors a more uniform stress distribution in both attachments compared to a much greater stress registered with unilateral load in the load side attachments. Regardless of the implant positions and the occlusal load application site, the stress transferred to the insert plastic is much lower than that registered in the abutment.
Bicuspid
;
Clothing
;
Denture, Overlay*
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Finite Element Analysis
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Incisor
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Mandible
;
Plastics
3.Role of Endoscopy in the Management of Boerhaave Syndrome.
Juan Ignacio TELLECHEA ; Jean Michel GONZALEZ ; Pablo MIRANDA-GARCÍA ; Adrian CULETTO ; Xavier Benoit D'JOURNO ; Pascal Alexandre THOMAS ; Marc BARTHET
Clinical Endoscopy 2018;51(2):186-191
Boerhaave syndrome (BS) is a spontaneous esophageal perforation which carries high mortality. Surgical treatment is well established, but the development of interventional endoscopy has proposed new therapies. We expose our experience in a Gastrointestinal and Endoscopy Unit. With a retrospective, observational, open-label, single center, consecutive case series. All patients diagnosed with BS who were managed in our center were included. Treated conservatively, endoscopically or surgically, according to their clinical condition and lesion presentation. Fourteen patients were included. Ten were treated with primary surgery. One conservatively. In total, 7/14 patients required an endoscopic treatment. All required metallic stents deployment, 3 cases over-the-scope-clips concomitantly and one case a novel technique an internal drain. 6/7 cases endoscopically treated achieved complete esophageal healing. In conclusion, endoscopy is an useful tool at all stages BS management: difficult diagnosis, primary treatment in selected patients and as salvage when surgery fails. With mortality rates and outcomes comparables to surgery.
Diagnosis
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Endoscopy*
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Esophageal Perforation
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Humans
;
Minimally Invasive Surgical Procedures
;
Mortality
;
Retrospective Studies
;
Stents
;
Surgical Instruments