| 1. |
- Berglundh, Tord, 1954, et al.
(author)
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Peri-implant diseases and conditions: Consensus report of workgroup 4 of the 2017 World Workshop on the Classification of Periodontal and Peri-Implant Diseases and Conditions
- 2018
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In: J Clin Periodontol. - : Wiley. - 0303-6979 .- 1600-051X. ; 45
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Journal article (peer-reviewed)abstract
- A classification for peri-implant diseases and conditions was presented. Focused questions on the characteristics of peri-implant health, peri-implant mucositis, peri-implantitis, and soft- and hard-tissue deficiencies were addressed. Peri-implant health is characterized by the absence of erythema, bleeding on probing, swelling, and suppuration. It is not possible to define a range of probing depths compatible with health; Peri-implant health can exist around implants with reduced bone support. The main clinical characteristic of peri-implant mucositis is bleeding on gentle probing. Erythema, swelling, and/or suppuration may also be present. An increase in probing depth is often observed in the presence of peri-implant mucositis due to swelling or decrease in probing resistance. There is strong evidence from animal and human experimental studies that plaque is the etiological factor for peri-implant mucositis. Peri-implantitis is a plaque-associated pathological condition occurring in tissues around dental implants, characterized by inflammation in the peri-implant mucosa and subsequent progressive loss of supporting bone. Peri-implantitis sites exhibit clinical signs of inflammation, bleeding on probing, and/or suppuration, increased probing depths and/or recession of the mucosal margin in addition to radiographic bone loss. The evidence is equivocal regarding the effect of keratinized mucosa on the long-term health of the peri-implant tissue. It appears, however, that keratinized mucosa may have advantages regarding patient comfort and ease of plaque removal. Case definitions in day-to-day clinical practice and in epidemiological or disease-surveillance studies for peri-implant health, peri-implant mucositis, and peri-implantitis were introduced. The proposed case definitions should be viewed within the context that there is no generic implant and that there are numerous implant designs with different surface characteristics, surgical and loading protocols. It is recommended that the clinician obtain baseline radiographic and probing measurements following the completion of the implant-supported prosthesis.
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| 2. |
- Berglundh, Tord, 1954, et al.
(author)
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Peri-implant diseases and conditions: Consensus report of workgroup 4 of the 2017 World Workshop on the Classification of Periodontal and Peri-Implant Diseases and Conditions
- 2018
-
In: Journal of Periodontology. - : Wiley. - 0022-3492. ; 89
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Journal article (peer-reviewed)abstract
- A classification for peri-implant diseases and conditions was presented. Focused questions on the characteristics of peri-implant health, peri-implant mucositis, peri-implantitis, and soft- and hard-tissue deficiencies were addressed. Peri-implant health is characterized by the absence of erythema, bleeding on probing, swelling, and suppuration. It is not possible to define a range of probing depths compatible with health; Peri-implant health can exist around implants with reduced bone support. The main clinical characteristic of peri-implant mucositis is bleeding on gentle probing. Erythema, swelling, and/or suppuration may also be present. An increase in probing depth is often observed in the presence of peri-implant mucositis due to swelling or decrease in probing resistance. There is strong evidence from animal and human experimental studies that plaque is the etiological factor for peri-implant mucositis. Peri-implantitis is a plaque-associated pathological condition occurring in tissues around dental implants, characterized by inflammation in the peri-implant mucosa and subsequent progressive loss of supporting bone. Peri-implantitis sites exhibit clinical signs of inflammation, bleeding on probing, and/or suppuration, increased probing depths and/or recession of the mucosal margin in addition to radiographic bone loss. The evidence is equivocal regarding the effect of keratinized mucosa on the long-term health of the peri-implant tissue. It appears, however, that keratinized mucosa may have advantages regarding patient comfort and ease of plaque removal. Case definitions in day-to-day clinical practice and in epidemiological or disease-surveillance studies for peri-implant health, peri-implant mucositis, and peri-implantitis were introduced. The proposed case definitions should be viewed within the context that there is no generic implant and that there are numerous implant designs with different surface characteristics, surgical and loading protocols. It is recommended that the clinician obtain baseline radiographic and probing measurements following the completion of the implant-supported prosthesis.
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| 3. |
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| 4. |
- Renvert, Stefan, et al.
(author)
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Risk indicators for peri-implantitis : a narrative review
- 2015
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In: Clinical Oral Implants Research. - 0905-7161 .- 1600-0501. ; 26, s. 15-44
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Journal article (peer-reviewed)abstract
- Aim: To examine the existing evidence in identifying risk indicators in the etiology of peri-implantitis. Material and methods: A literature search was performed in MEDLINE via PubMed database of the US National Library of Medicine, for articles published until October 2014 using Medical Subject Heading search terms + free text terms and in different combinations. Results: The microbiota associated with peri-implantitis is complex, demonstrating differences and similarities to the one seen at periodontitis sites. Plaque accumulation at dental implants triggers the inflammatory response leading to peri-implant mucositis/peri-implantitis. Individuals with a history of periodontal disease and smokers have an increased risk of developing peri-implantitis. There is some evidence to support the role of genetic polymorphism, diabetes, and excess cement as risk indicators for the development of peri-implantitis. There is also evidence to support that individuals on regular maintenance are less likely to develop peri-implantitis and that successful treatment of periodontitis prior to implant placement lowers the risk of peri-implantitis. Conclusions: Plaque accumulation at implants will result in the development of an inflammation at implants. A history of periodontal disease, smoking, excess cement, and lack of supportive therapy should be considered as risk indicators for the development of peri-implantitis.
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| 5. |
- Gros, Sébastien, 1977, et al.
(author)
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An improved real-time economic NMPC scheme for Wind Turbine control using spline-interpolated aerodynamic coefficients
- 2015
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In: Proceedings of the IEEE Conference on Decision and Control. - 2576-2370 .- 0743-1546. ; 2015-February, s. 935-940
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Conference paper (peer-reviewed)abstract
- Nonlinear Model Predictive Control (NMPC) is a strong candidate for the control of large Multi-Mega Watt Wind Turbine Generators (WTG), especially when reliable Light Detection And Ranging (LIDAR) systems are available. Recently, a real-time NMPC for WTG control has been proposed, but had a limited reliability if deployed over the full WTG operating range due to the difficulty of handling the WTG aerodynamic coefficients over a large domain and of using a Gauss-Newton Hessian. In this paper, we address these two issues. A fast surface B-spline code has been developed specifically to tackle the interpolation of the aerodynamic coefficients for NMPC-based WTG control. A novel Hessian approximation for the NMPC problem is used, for which an efficient and inexpensive regularization is proposed. The approach presented is real-time feasible, and accurate over the full operating range of the WTG.
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| 6. |
- Merheb, J., et al.
(author)
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Influence of Skeletal and Local Bone Density on Dental Implant Stability in Patients with Osteoporosis
- 2016
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In: Clinical Implant Dentistry and Related Research. - : Wiley. - 1523-0899 .- 1708-8208. ; 18:2, s. 253-260
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Journal article (peer-reviewed)abstract
- Background and PurposeOsteoporosis is a major skeletal disease affecting millions of people worldwide. Recent studies claim that patients with osteoporosis do not have a higher risk of early implant failure compared to non-osteoporotic patients. The aim of this study was to assess the effect of skeletal osteoporosis and local bone density on initial dental implant stability. Materials and MethodsSeventy-three patients were recruited and were assigned (based on a Dual-energy X-ray Absorptiometry scan) to either the osteoporosis (Opr), osteopenia (Opn), or control (C) group. Forty nine of the 73 patients received dental implants and had implant stability measured by means of resonance frequency analysis (RFA) at implant placement and at prosthetic abutment placement. On the computerized tomography scans, the cortical thickness and the bone density (Hounsfield Units) at the sites of implant placement were measured. ResultsAt implant placement, primary stability was on average lower in group Opr (63.310.3 ISQ) than in group Opn (65.3 +/- 7.5 implant stability qutient (ISQ)), and group C (66.7 +/- 8.7 ISQ). At abutment placement, a similar trend was observed: group Opr (66.4 +/- 9.5 ISQ) scored lower than group Opn (70.7 +/- 7.8 ISQ), while the highest average was for group C (72.2 +/- 7.2 ISQ). The difference between groups Opr and C was significant. Implant length and diameter did not have a significant effect on implant stability as measured with RFA. A significant correlation was found between local bone density and implant stability for all regions of interest. ConclusionsImplant stability seems to be influenced by both local and skeletal bone densities. The lower stability scores in patient with skeletal osteoporosis reinforce the recommendations that safe protocols and longer healing times could be recommended when treating those patients with dental implants.
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| 7. |
- Merheb, J., et al.
(author)
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Relation between Spongy Bone Density in the Maxilla and Skeletal Bone Density
- 2015
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In: Clinical Implant Dentistry and Related Research. - : Wiley. - 1523-0899 .- 1708-8208. ; 17:6, s. 1180-1187
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Journal article (peer-reviewed)abstract
- © 2015 Wiley Periodicals, Inc. Background and Purpose: Osteoporosis is a disease affecting more than 300 million people worldwide and is responsible for numerous medical complications. This study aimed to investigate the relation between skeletal and maxillary bone density. Materials and Methods: Seventy-three patients were recruited and divided between group A (osteoporosis), group B (healthy, control), and group C (osteopenia) on the basis of a dual-energy x-ray absorptiomery (DXA) scan. These patients also received a CT scan on which bone density measurements were performed at five sites: maxilla midline, retromolar tuberosities, incisor, premolars, and molar regions. Results: The bone density was lower in osteoporotic patients compared with the control patients. The bone mineral density (BMD) of the tuberosities showed the strongest correlations with the BMD of the hip and the spine (respectively, r=0.50 and r=0.61). The midline region showed moderate correlations with the hip (r=0.47) and the spine (r=0.46). For potential implant sites, the correlations with the BMD of the hip and spine were, however, small to insignificant. Based on measurements of bone density of the maxilla, it was possible to predict if the patient was osteoporotic or not with a sensitivity of 65% and a specificity of 83%. Conclusions: The maxillary bone density of subjects with osteoporosis is significantly lower than that of healthy patients. Moreover, there is a direct correlation between the density of the skeleton and the density of some sites of the maxilla. Using measurements of maxillary bone density in order to predict skeletal bone density might be a useful tool for the screening of osteoporosis.
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| 8. |
- Temmerman, A., et al.
(author)
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A Prospective, Controlled, Multicenter Study to Evaluate the Clinical Outcome of Implant Treatment in Women with Osteoporosis/Osteopenia: 5-Year Results
- 2019
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In: Journal of Dental Research. - : SAGE Publications. - 0022-0345 .- 1544-0591. ; 98:1, s. 84-90
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Journal article (peer-reviewed)abstract
- The impact of osteoporosis on implant treatment is still a matter of debate in the scientific community, as it may possibly lead to higher failure rates. As long-term controlled trials are missing, the aim of this study was to verify the long-term outcome of implants placed in patients with systemic osteoporosis. Postmenopausal women in need of implants underwent bone mineral density measurements in hip and spine, using dual X-ray absorptiometry scans. Based on T-scores, they were divided into 2 groups: group O (osteoporosis group) with a T-score <=-2 or group C (control group) with a T-score of >=-1. Implants were placed in a 2-stage manner and loaded 4 to 8 wk after abutment surgery. Six months after loading and thereafter yearly, clinical and radiographical parameters were assessed. In total, 148 implants were placed in 48 patients (mean age: 67 y [range, 59-83]). Sixty-three implants were placed in 20 patients (group O) and 85 implants in 28 patients (group C). After 5 y, 117 implants (38 in group O and 79 in the group C) in 37 patients were assessed. Cumulative survival rate on an implant level was 96.5% (group O: 91.5%; group C: 100.0% [P < 0.05]) and 95.7% (group O: 89.2%; group C: 100.0% [P > 0.05]) on a patient level. The overall marginal bone-level alterations, after 5 y of loading, were -0.09 +/- 0.78 mm (group O: -0.15 +/- 0.50 mm; group C: -0.06 +/- 0.89 mm) on an implant level and -0.09 +/- 0.54 mm (group O: -0.18 +/- 0.43 mm; group C: 0.06 +/- 0.58 mm) on a patient level (P > 0.05). Oral implant therapy in osteoporotic patients is a reliable treatment option with comparable osseointegration rates, implant survival, and marginal bone-level alterations after 5 y of functional loading (ClinicalTrials.gov NCT00745121).
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| 9. |
- Verschueren, R., et al.
(author)
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A Sparsity Preserving Convexification Procedure for Indefinite Quadratic Programs Arising in Direct Optimal Control
- 2017
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In: SIAM Journal on Optimization. - : Society for Industrial & Applied Mathematics (SIAM). - 1052-6234 .- 1095-7189. ; 27:3, s. 2085-2109
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Journal article (peer-reviewed)abstract
- Quadratic programs (QP) with an indefinite Hessian matrix arise naturally in some direct optimal control methods, e.g., as subproblems in a sequential quadratic programming scheme. Typically, the Hessian is approximated with a positive de finite matrix to ensure having a unique solution; such a procedure is called regularization. We present a novel regularization method tailored for QPs with optimal control structure. Our approach exhibits three main advantages. First, when the QP satisfies a second order sufficient condition for optimality, the primal solution of the original and the regularized problem are equal. In addition, the algorithm recovers the dual solution in a convenient way. Second, and more importantly, the regularized Hessian bears the same sparsity structure as the original one. This allows for the use of efficient structure-exploiting QP solvers. As a third advantage, the regularization can be performed with a computational complexity that scales linearly in the length of the control horizon. We showcase the properties of our regularization algorithm on a numerical example for nonlinear optimal control. The results are compared to other sparsity preserving regularization methods.
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