| 1. |
- Derks, Jan, 1977, et al.
(författare)
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Reconstructive surgical therapy of peri-implantitis: A multicenter randomized controlled clinical trial
- 2022
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Ingår i: Clinical Oral Implants Research. - : Wiley. - 0905-7161 .- 1600-0501. ; 33:9, s. 921-944
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Tidskriftsartikel (refereegranskat)abstract
- Objective To evaluate the potential benefit of the use of a bone substitute material in the reconstructive surgical therapy of peri-implantitis. Methods In this multicenter randomized clinical trial, 138 patients (147 implants) with peri-implantitis were treated surgically, randomized by coin toss to either a control (access flap surgery) or a test group (reconstructive surgery using bone substitute material). Clinical assessments, including probing pocket depth (PPD), bleeding and suppuration on probing (BOP & SOP) as well as soft tissue recession (REC), were recorded at baseline, 6 and 12 months. Marginal bone levels (MBL), measured on intra-oral radiographs, and patient-reported outcomes (PROs) were recorded at baseline and 12 months. No blinding to group allocation was performed. The primary outcome at 12 months was a composite measure including (i) implant not lost, (ii) absence of BOP/SOP at all aspects, (iii) PPD <= 5 mm at all aspects and (iv) <= 1 mm recession of mucosal margin on the buccal aspect of the implant. Secondary outcomes included (i) changes of MBL, (ii) changes of PPD, BOP%, and buccal KM, (iii) buccal REC and (iv) patient-reported outcomes. Results During follow-up, four implants (one in the test group, three in the control group) in four patients were removed due to disease progression. At 12 months, a total of 69 implants in the test and 68 implants in the control group were examined. Thus, 16.4% and 13.5% of implants in the test and control group, respectively, met all predefined criteria of the composite outcome. PPD reduction and MBL gain were 3.7 mm and about 1.0 mm in both groups. Reduction in mean BOP% varied between 45% (test) and 50% (control), without significant differences between groups. Buccal REC was less pronounced in the test group (M = 0.7, SD = 0.9 mm) when compared to controls (M = 1.1, SD = 1.5 mm). PROs were favorable in both groups without significant differences. One case of allergic reaction to the antibiotic therapy was recorded. No other adverse events were noted. Conclusions Surgical therapy of peri-implantitis effectively improved the clinical and radiographic status at 12 months. While the use of a bone substitute material did not improve reductions of PPD and BOP, buccal REC was less pronounced in the test group. Patient satisfaction was high in both groups.
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| 2. |
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| 3. |
- Ichioka, Yuki, et al.
(författare)
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Factors influencing outcomes of surgical therapy of peri-implantitis: A secondary analysis of 1-year results from a randomized clinical study
- 2023
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Ingår i: JOURNAL OF CLINICAL PERIODONTOLOGY. - 0303-6979. ; 50:10, s. 1282-1304
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Tidskriftsartikel (refereegranskat)abstract
- Aim: To identify predictors of treatment outcomes following surgical therapy of peri-implantitis.Materials and Methods: We performed a secondary analysis of data from a randomized controlled trial (RCT) comparing access flap with or without bone replacement graft. Outcomes at 12 months were probing pocket depth (PPD), bleeding on probing (BOP), soft-tissue recession (REC) and marginal bone level (MBL) change. Multilevel regression analyses were used to identify predictors. We also built an explanatory model for residual signs of inflammation.Results: Baseline PPD was the most relevant predictor, showing positive associations with final PPD, REC and MBL gain, and negative association with probability of pocket closure. Smokers presented higher residual PPD. Absence of keratinized mucosa at baseline increased the probability of BOP but was otherwise not indicative of outcomes. Plaque at 6 weeks was detrimental in terms of residual PPD and BOP. Treatment allocation had an effect on REC. Final BOP was explained by residual PPD & GE;6 mm and plaque at more than two sites.Conclusions: Baseline PPD was the most relevant predictor of the outcomes of surgical therapy of peri-implantitis. Pocket closure should be a primary goal of treatment. Bone replacement grafts may be indicated in aesthetically demanding cases to reduce soft-tissue recession. The importance of smoking cessation and patient-performed plaque control is also underlined.
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| 4. |
- Karlsson, Karolina, 1975, et al.
(författare)
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Health economic aspects of implant-supported restorative therapy
- 2022
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Ingår i: Clinical Oral Implants Research. - : Wiley. - 0905-7161 .- 1600-0501. ; 33:2, s. 221-230
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Tidskriftsartikel (refereegranskat)abstract
- Background: It is poorly understood how much additional dental care patients consume subsequent to implant therapy. The aim of the present study is to evaluate costs associated with implant-supported restorative therapy during the long-term follow-up. Material and Methods: Costs associated with preventive measures and complication-related procedures over a mean follow-up period of 8.2years were assessed in patient files of 514 Swedish subjects provided with implant-supported restorative therapy. The restorative therapy and each of the subsequent interventions were assigned a specific cost. Accumulated costs were calculated in three categories: (i) total cost including initial restorative therapy and complication-related interventions, (ii) cost of preventive measures alone, and (iii) cost of complication-related procedures alone. Potential differences by background variables were analyzed using growth curve models. Results: In the whole sample, costs during follow-up ranged from 878 € (95% CI 743; 1,014) for patients with single-tooth restoration(s) to 1,210 € (95% CI 1,091; 1,329) for subjects with full-jaw restoration(s). The majority of costs during follow-up originated from preventive measures (741 € 95% CI 716; 766). Among individuals receiving ≥1 intervention dealing with a complication (n=253), complication-related costs amounted to 557 € (95% CI 480; 634). For patients with full-jaw restorations, the corresponding amount was 769 € (95% CI 622; 916). Procedures related to peri-implantitis and technical complications resulted in costs similar to each other. Implant loss generated greater costs than any other type of complication. Conclusions: Costs related to implant-supported restorative therapy during follow-up were associated with the extent of initial therapy. The higher costs during follow-up noted in patients provided with full-jaw restorations were explained by complication-associated procedures. Implant loss was the most costly type of complication.
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| 5. |
- Karlsson, Karolina, 1975, et al.
(författare)
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Interventions for peri-implantitis and their effects on further bone loss: A retrospective analysis of a registry-based cohort
- 2019
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Ingår i: Journal of Clinical Periodontology. - : Wiley. - 0303-6979 .- 1600-051X. ; 46:8, s. 872-879
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Tidskriftsartikel (refereegranskat)abstract
- Objective The aim of the present study was to assess interventions and their consequences with regard to further bone loss at sites diagnosed with peri-implantitis. Materials and Methods In 2017, records of 70 patients diagnosed with moderate/severe peri-implantitis at >= 1 implant sites 4 years earlier were obtained. Changes of marginal bone levels during the study period assessed on radiographs and predictors of disease progression were identified by Cox regression and mixed linear modelling. Patient files were analysed for professional interventions related to the treatment of peri-implantitis. Results Mean bone loss (+/- SD) at implants diagnosed with moderate/severe peri-implantitis was 1.1 +/- 2.0 mm over the observation period of 3.3 years. While non-surgical measures including submucosal and/or supra-mucosal cleaning of implants were provided to almost all patients, surgical treatment of peri-implantitis was limited to a subgroup (17 subjects). Surgically treated implant sites demonstrated a mean bone loss of 1.4 +/- 2.4 mm prior to surgical intervention, while only minor changes (0.2 +/- 1.0 mm) occurred after therapy. Clinical parameters (bleeding/suppuration on probing and probing depth) assessed at diagnosis were statistically significant predictors of disease progression. Conclusions Non-surgical procedures were insufficient to prevent further bone loss at implant sites affected by moderate/severe peri-implantitis. Surgical treatment of peri-implantitis markedly diminished the progression of bone loss. Clinical assessments of bleeding on probing and probing depth at diagnosis predicted further bone loss.
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| 6. |
- Karlsson, Karolina, 1975, et al.
(författare)
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Occurrence and clustering of complications in implant dentistry
- 2020
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Ingår i: Clinical Oral Implants Research. - : Wiley. - 0905-7161 .- 1600-0501. ; 31:10, s. 1002-1009
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Tidskriftsartikel (refereegranskat)abstract
- Objectives The aim was to evaluate the overall occurrence and potential clustering of biological and technical complications in implant dentistry. Material and Methods 596 patients provided with implant-supported reconstructions were evaluated for the occurrence of (a) technical complications, (b) peri-implantitis and (c) implant loss during a period of 9 years. Time and type of event were scored, and potential risk factors were explored through parametric modelling of survival and hazards. Clustering of complications was assessed at the patient level, and patient satisfaction was evaluated by questionnaire completed at the 9-year examination. Results 42% of patients were affected by technical and/or biological complications during the 9-year observation period. Extent of therapy (Hazard Ratio 2.5: patients with partial jaw restorations; HR 3.9: patients with full jaw restorations) and a history of periodontitis (HR 1.6) were identified as risk factors. While technical complications occurred mostly as isolated events, 41% of subjects identified with peri-implantitis and 52% of subjects with implant loss also presented with other complications. The hazard for technical complications and implant loss peaked at 0.7 years and 0.2 years, respectively, while the hazard for peri-implantitis was consistent throughout the observation period. The overall proportion of satisfied patients at 9 years was high (95%), and only minor differences between individuals with and without complications were noted. Conclusions Complications following implant-supported restorative therapy were common findings. Extent of therapy and periodontitis were identified as risk factors. While technical complications occurred in an isolated pattern, peri-implantitis and implant loss demonstrated clustering with other types of complications.
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| 7. |
- Karlsson, Karolina, 1975, et al.
(författare)
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Technical complications following implant-supported restorative therapy performed in Sweden
- 2018
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Ingår i: Clinical Oral Implants Research. - : Wiley. - 0905-7161 .- 1600-0501. ; 29:6, s. 603-611
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Tidskriftsartikel (refereegranskat)abstract
- ObjectiveThe aim of this study was to evaluate the occurrence and consequences of technical complications in implant-supported restorative therapy. Material & MethodsThe occurrence and consequences of technical complications in implant-supported restorative therapy over a mean follow-up period of 5.3years were assessed based on documentation in files from 2,666 patients. Risk indicators were identified by the use of survival models, considering repeated events. Results were expressed as hazard ratios (HR) including 95% confidence intervals. ResultsTechnical complications occurred in 24.8% of the patients. Chipping and loss of retention were the most common, affecting 11.0% and 7.9% of supraconstructions, respectively, while implant-related complications (e.g., implant fracture) were rare. More than 50% of the affected patients experienced technical complications more than once and almost all reported complications led to interventions by a dental professional. The extent of the supraconstruction was the strongest risk indicator for both chipping (HR<0.2) and loss of retention (HR>3). ConclusionOver a 5-year period, technical complications in implant-supported restorative therapy occurred frequently and their management required professional intervention.
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| 8. |
- Karlsson, Tord, 1975
(författare)
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Comparison of flow fields of a pure fluid and a zeotropic mixture for condensation in a shell-and-tube condenser
- 2005
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Ingår i: Proceedings of International energy agency heat pump conference, May 30 to June 2 2005, Ceasars Palace, Las Vegas, USA. ; , s. Paper P6-5
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Konferensbidrag (refereegranskat)abstract
- Condensation of a pure refrigerant and a zeotropic refrigerant mixture in a shell-and-tube condenser is investigated in an advanced calculation model based on a developed condensation routine coupled to a commercial CFD program. The aim of the investigation is to make a three-dimensional calculation model for mixture condensation, and to see if previous results from 2D calculations also can be seen in 3D calculations, namely a significant difference between the flow fields of a pure fluid and a mixture. The calculation results presented here show the same tendencies as 2D calculations in the earlier work. The flow field of the mixture is much more complex than that of the pure refrigerant. Large vortexes arise, starting at the top of the shell, going down along the shell and into the tube bundle from below. Vapour is therefore mainly fed from below, causing a counterflow between vapour and condensate. A well-mixed condensate, which here is an unfavourable situation, results in a performance 30 % lower compared to the case where the condensate phase is unmixed. The latter is normally considered to be the inferior case.
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| 9. |
- Karlsson, Tord, 1975, et al.
(författare)
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Comparison of Heat Transfer for R22 and some Alternatives in a 25 MW Shell-and-Tube Condenser
- 2000
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Ingår i: (Presented at the 8th Int. Refrigeration Conf., Purdue, USA, July 25-28, 2000.). - 1404-7098.
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Konferensbidrag (refereegranskat)abstract
- Calculations have been carried out for a 25 MW horizontal shell-and-tube condenser with shell-side condensation, part of a heat pump for district heating. Due to a coming ban on refilling R22, which is used in some district heating heat pumps, calculations of heat transfer were carried out for R22, R134a and four zeotropic refrigerant mixtures, to see how well they perform. It was found that some of the refrigerant mixtures are competitive to R134a as replacement for R22. Two comparisons were made, one for fixed duty and one for a fixed heat pump system. In both comparisons some of the mixtures seem to have better performance than R134a when considering duty and heat transfer whilst maintaining lower flow rates.
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| 10. |
- Karlsson, Tord, 1975, et al.
(författare)
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Condensation of mixtures in shell-and-tube condensers – the influence of important factors on calculation results
- 2002
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Ingår i: 1st Int. Conf. On Heat Transfer, Fluid Mechanics, and Thermodynamics 8-10 April 2002, Kruger Park, South Africa. - 1404-7098.
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Konferensbidrag (refereegranskat)abstract
- Calculations are carried out for condensation ofzeotropic refrigerant mixtures in a horizontal shell-andtubecondenser, in order to investigate possible causesfor overpredictions of heat transfer found whencomparing with experimental data. A rigorouscalculation method is compared to an earlier usedsimplified method, and to experimental measurements,but the rigorous method turns out to predict even betterheat transfer. Mass transfer in the gas phase is calculatedto reduce heat transfer up to 10%, but this effect cannotalone explain the overprediction of heat transfer.However, investigations show that the degree of mixingin the condensate layer is of great importance, and canbe one important reason for the overprediction.Geometry data turned out to have only minor effects on calculation results.
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