Hemorrhagic colitis induced by trientine in a 51-year-old patient with Wilson's disease waiting for liver transplantation: A case report.

BACKGROUND: Wilson's disease (WD) is a rare inherited disorder of copper metabolism. Treatment consists of chelating agents, but side effects are common. We describe a patient who developed colitis during trientine treatment leading to decompensation of liver cirrhosis. CASE SUMMARY: A healthy 51-year-old woman was diagnosed with liver cirrhosis due to decompensation with ascites. Etiologic evaluation raised suspicion of hereditary hemochromatosis because of compound heterozygosity HFE p.C282Y/p.H63D, and phlebotomy was started. Re-evaluation showed low ceruloplasmin, increased urinary copper excretion and the presence of Kayser-Fleischer rings. WD was confirmed by genetic analysis. Because of decompensated cirrhosis, she was referred for liver transplant evaluation. Simultaneously, treatment with trientine was initiated. Liver function initially stabilized, and the patient was not accepted for a liver transplant. Shortly after this, she developed severe hemorrhagic colitis, most probably a side effect of trientine. During that episode, she decompensated with hepatic encephalopathy. Because of a second decompensating event, she was accepted for liver transplantation, and an uneventful transplantation was carried out after clinical improvement of colitis. CONCLUSION: Despite WD being a rare disorder, it is important to consider because it can present with a plethora of symptoms from childhood to an elderly age. Colitis should be recognized as a serious adverse drug reaction to trientine treatment that can result in decompensated liver disease.

Virtual variation simulation of CAD/CAM template-guided surgeries performed on human cadavers: Part II.

STATEMENT OF PROBLEM: CAD/CAM template-guided surgery has gained attention as a method of improving the predictability of dental implant placement. However, due to possible variations during the manufacturing process and in the robustness of the template design, a virtual prediction of the potential positioning of the implants is needed. PURPOSE: The purpose of this study was to perform virtual variation simulations on virtually planned implant placements and to compare them with corresponding results from actual surgeries performed on human cadavers in a previous study. MATERIAL AND METHODS: Seventeen computer-aided plans were used for virtual variation simulation of surgeries conducted on 17 human cadavers and 145 implants placed in the cadavers. For each surgery, 10,000 virtual surgeries were performed, resulting in 1,450,000 implant placements. The results from the virtual variation simulations were statistically compared with the results from the actual surgeries. The Mann-Whitney U test was used to compare the implant distributions (alpha=.05). RESULTS: In the maxillae, the difference between the simulated average mean of the mean and the compared surgical average of the median was 0.22 mm (apex) and -0.35 mm (hex), and for the mandible, the corresponding values were -0.19 mm (apex) and -0.69 mm (hex). The simulated average mean of the range compared to the mean range of the maximum deviation results from the surgeries of the maxillae was 2.96 mm (apex) and 0.44 mm (hex), and 2.3 mm (apex) and 0.26 mm (hex) for the mandible. The implant distributions between the simulations and the surgeries were significantly different at both the hex (P<.001) and apex (P<.001). CONCLUSIONS: The implant distributions were neither static nor normally distributed. Thus, within the limitations of this study, the definitive geometrical variations of the implants were not static, as they depend on the individual anatomy of the jaws and the ability to place the CAD/CAM-guided surgical template in the proper position.

Digitization of simulated clinical dental impressions: virtual three-dimensional analysis of exactness.

OBJECTIVES: To compare the exactness of simulated clinical impressions and stone replicas of crown preparations, using digitization and virtual three-dimensional analysis. METHODS: Three master dies (mandibular incisor, canine and molar) were prepared for full crowns, mounted in full dental arches in a plane line articulator. Eight impressions were taken using an experimental monophase vinyl polysiloxane-based material. Stone replicas were poured in type IV stone (Vel-Mix Stone; Kerr). The master dies and the stone replicas were digitized in a touch-probe scanner (Procera) Forte; Nobel Biocare AB) and the impressions in a laser scanner (D250, 3Shape A/S), to create virtual models. The resulting point-clouds from the digitization of the master dies were used as CAD-Reference-Models (CRM). Discrepancies between the points in the pointclouds and the corresponding CRM were measured by a matching-software (CopyCAD 6.504 SP2; Delcam Plc). The distribution of the discrepancies was analyzed and depicted on color-difference maps. RESULTS: The discrepancies of the digitized impressions and the stone replicas compared to the CRM were of similar size with a mean+/-SD within 40microm, with the exception of two of the digitized molar impressions. The precision of the digitized impressions and stone replicas did not differ significantly (F=4.2; p=0.053). However, the shape affected the digitization (F=5.4; p=0.013) and the interaction effect of shape and digitization source (impression or stone replica) was pronounced (F=28; p<0.0001). The reliability was high for both digitization methods, evaluated by repeated digitizations. SIGNIFICANCE: The exactness of the digitized impressions varied with shape. Both impressions and stone replicas can be digitized repeatedly with a high reliability.

Computer aided analysis of digitized dental stone replicas by dental CAD/CAM technology.

OBJECTIVES: To determine the reproducibility of digitized dental stone replicas compared to the master model and the reliability of the computer aided analysis. METHODS: Four master dies, prepared for complete crowns were fabricated in presintered yttria-stabilized tetragonal zirconia (Y-TZP). Eight vinyl polysiloxane impressions (PROVIL novo; Heraeus Kulzer) were taken of each die and stone replicas were poured in type IV stone (Vel-Mix Stone; Kerr). The master dies and the stone replicas were digitized in a touch-probe scanner (Procera Forte; Nobel Biocare AB), to create triangulated surface-models. The point-cloud from the first of the repeated digitizations of each master die was used as CAD-reference-models (CRM). Discrepancies between the points in the triangulated surface-models and the corresponding CRM were measured by a matching-software (CopyCAD 6.504 SP2; Delcam Plc). The distribution of the discrepancies was analyzed and presented in color-difference-maps. RESULTS: The precision of the measuring method, presented as the repeatability coefficient, ranged between 7 and 16 microm (entire surface), whereas the analysis of the stone replicas revealed a precision (repeatability coefficient) ranging from 19 to 26 microm. The accuracy of the replica to master (the mean discrepancy) ranged from 0.5 to 2.0 microm (95% confidence interval 1.5-2.9 microm). SIGNIFICANCE: The greatest precision of the measurement was seen in the jacket surface of the die. The size of the stone replicas varied and the repeatability coefficient was on average 15 microm (2-25 microm) greater for the replica-to-master alignment than the repeated digitizations of the master.

A three-dimensional evaluation of a laser scanner and a touch-probe scanner.

STATEMENT OF PROBLEM: The fit of a dental restoration depends on quality throughout the entire manufacturing process. There is difficulty in assessing the surface topography of an object with a complex form, such as teeth, since there is no exact reference form. PURPOSE: The purpose of this study was to determine the repeatability and relative accuracy of 2 dental surface digitization devices. A computer-aided design (CAD) technique was used for evaluation to calculate and present the deviations 3-dimensionally. MATERIAL AND METHODS: Ten dies of teeth prepared for complete crowns were fabricated in presintered yttria-stabilized tetragonal zirconia (Y-TZP). The surfaces were digitized 3 times each with an optical or mechanical digitizer. The number of points in the point clouds from each reading were calculated and used as the CAD reference model (CRM). Alignments were performed by registration software that works by minimizing a distance criterion. In color-difference maps, the distribution of the discrepancies between the surfaces in the CRM and the 3-dimensional surface models was identified and located. RESULTS: The repeatability of both scanners was within 10 microm, based on SD and absolute mean values. The qualitative evaluation resulted in an even distribution of the deviations in the optical digitizer, whereas the dominating part of the surfaces in the mechanical digitizer showed no deviations. The relative accuracy of the 2 surface digitization devices was within +/- 6 microm, based on median values. CONCLUSION: The repeatability of the optical digitizer was comparable with the mechanical digitization device, and the relative accuracy was similar.

A computed tomographic scan-derived customized surgical template and fixed prosthesis for flapless surgery and immediate loading of implants in fully edentulous maxillae: a prospective multicenter study.

BACKGROUND: Based on three-dimensional implant planning software for computed tomographic (CT) scan data, customized surgical templates and final dental prostheses could be designed to ensure high precision transfer of the implant treatment planning to the operative field and an immediate rigid splinting of the installed implants, respectively. PURPOSE: The aim of the present study was to (1) evaluate a concept including a treatment planning procedure based on CT scan images and a prefabricated fixed prosthetic reconstruction for immediate function in upper jaws using a flapless surgical technique and (2) validate the universality of this concept in a prospective multicenter clinical study. MATERIALS AND METHODS: Twenty-seven consecutive patients with edentulous maxillae were included. Treatments were performed according to the Teeth-in-an-Hour concept (Nobel Biocare AB, Göteborg, Sweden), which includes a CT scan-derived customized surgical template for flapless surgery and a prefabricated prosthetic suprastructure. RESULTS: All patients received their final prosthetic restoration immediately after implant placement, that is, both the surgery and the prosthesis insertion were completed within approximately 1 hour. In the 24 patients followed for 1 year, all prostheses and individual implants were recorded as stable. CONCLUSION: The present prospective multicenter study indicates that the prefabrication, on the basis of models derived from three-dimensional oral implant planning software, of both surgical templates for flapless surgery and dental prostheses for immediate loading is a very reliable treatment option. It is evident that the same approach could be used for staged surgery and in partial edentulism.

Health risks and occupational exposure to volatile anaesthetics--a review with a systematic approach.

AIMS AND OBJECTIVES: To provide practicing nurse anaesthetists with evidence based knowledge as to whether they are at risk handling volatile anaesthetics by answering the question: What are the health risks threatening health care personnel occupationally exposed to volatile anaesthetics? BACKGROUND: The interpretations of results from specific scientific studies vary and preliminary research results indicate that occupational exposure to volatile anaesthetics affects the health of operating room personnel. DESIGN: Review of scientific literature with a systematic approach. METHOD: The review included a systematic search in three major databases, a screening process of abstracts/articles followed by a quality assessment of the included studies. The screening process and the quality assessment were done independently by the six reviewers and followed specific protocols. RESULTS: A systematic search of The Cochrane Library, MedLine and CINAHL resulted in a screening of 413 abstracts of which 31 articles were assessed for quality, all done independently by the reviewers. Finally, the reviewers agreed upon how to interpret the results of the assessed articles. CONCLUSIONS: The 31 articles assessed covered areas such as genotoxic effects, neurobehavioural effects, immunology, and general health effects. In the scientific literature reviewed there is no evidence of occupational exposure to volatile anaesthetics either being associated with health risks or being harmless. Studies indicating a potential health risk are all investigating circumstances ignorant of modern environmental regulations and/or with no scavenging equipment. RELEVANCE TO CLINICAL PRACTICE: Although no answer has been given, this review illuminates the methodological difficulties encountered in designing studies. The result of this review further stresses the need for scientific knowledge in this area and enhances the extensive use of scavenging equipment.

Titanium dental copings prepared by a powder metallurgy method: a preliminary report.

PURPOSE: The purpose of this study was to determine if the Procera pressed-powder method can be used to fabricate titanium copings. MATERIALS AND METHODS: Commercially pure titanium powder was used to prepare the copings. The powder was pressed onto an enlarged tooth preparation die of aluminum using cold isostatic pressing. The outer shape of the coping was formed using a Procera milling machine, and the copings were vacuum sintered. RESULTS: Titanium copings could be prepared using this method. The density of the sintered copings reached 97% to 99%+ of theoretic density, and the copings showed ductile behavior after sintering. Enlarging the tooth preparation die to compensate for the sintering shrinkage could optimize the final size of the copings. CONCLUSION: Ductile and dense titanium dental copings can be produced with powder-metal processing using cold isostatic pressing, followed by milling and sintering to final shape. The forming technique has, if properly optimized, a potential of becoming a more cost-efficient production method than spark erosion.

All-ceramic crowns and preparation characteristics: a mathematic approach.

PURPOSE: The purpose of this investigation was to compare two mathematically calculated preparation parameters, ie, retentive capacity and finish line type, with a visual characterization based on a 3-D projection of the same prepared teeth on a PC screen. MATERIALS AND METHODS: Data from 400 teeth prepared for all-ceramic crowns recorded and manufactured by the Procera system, ie, 100 teeth each of types 11, 13, 14, and 16, were selected. Teeth were visually characterized for retentive capacity as good, acceptable, or insufficient, and type of finish line was characterized as deep chamfer, chamfer, or knife edge. For the mathematic calculations, data points located along vertical lines every 10 degrees around the tooth from finish line to occlusal/incisal midpoint were selected to calculate retentive area, defined as the part of the axial walls with an angle of less than 10 degrees to the preparation midline, and the area at the finish line with an angle of more than 45 degrees to the midline. RESULTS: Significant differences were found between the calculated size of surface areas for all types of prepared teeth visually characterized as having good retention and the two other categories (acceptable and insufficient). The difference between the latter two categories was not significant. Significant differences were also found between calculated surface areas for teeth visually characterized as having a deep chamfer and the two other finish line categories, ie, small chamfer and knife edge, but not between the latter two categories. CONCLUSION: The mathematic program allows a characterization of preparation parameters and may be further developed for use in prospective or retrospective studies of CAD/CAM restorations.

A custom template and definitive prosthesis allowing immediate implant loading in the maxilla: a clinical report.

PURPOSE: The purpose of the present investigation was to examine to what extent precision data from 3-dimensional planning software for oral implants can be transferred to the operative field by means of a drilling template, containing high-precision drilling sleeves, fitted on the jawbone. It was investigated whether this procedure would allow advance preparation of a fixed definitive prosthesis that could be placed at the completion of surgery. MATERIALS AND METHODS: This procedure was experimentally carried out in 2 cadavers and later in 8 consecutive human patients. RESULTS: The results indicated a nearly perfect match between the positions and axes of the placed implants and those planned. DISCUSSION: This procedure permitted the placement of a definitive fixed prosthesis with limited freedom of space between the abutments and the metallic cylinders incorporated into the prosthesis. CONCLUSION: These encouraging results of the Leuven information technology-based oral rehabilitation by means of implants (LITORIM) are presently being further investigated at the clinical level.