| 1. |
- Bougas, Kostas, et al.
(författare)
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Bone apposition to laminin-1 coated implants : Histologic and 3D evaluation
- 2013
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Ingår i: International Journal of Oral and Maxillofacial Surgery. - : Elsevier BV. - 0901-5027 .- 1399-0020. ; 42:5, s. 677-682
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Tidskriftsartikel (refereegranskat)abstract
- Laminin-1 has been reported as one of the factors responsible for the nucleation of calcium phosphates and, in vitro, has been reported to selectively recruit osteoprogenitors. This article focused on its in vivo effects, and evaluated the effect of laminin-1 local application on osseointegration. Polished cylindrical hydroxyapatite implants were coated with laminin-1 (test) and the bone responses in the rabbit tibiae after 2 and 4 weeks were evaluated and compared to the non-coated implants (control). Before the samples were processed for histological sectioning, they were three-dimensionally analysed with micro computed tomography (μCT). Both evaluation methods were analysed with regards to bone area around the implant and bone to implant contact. From the histologic observation, new bone formation around the laminin-1 coated implant at 2 weeks seemed to have increased the amount of supporting bone around the implant, however, at 4 weeks, the two groups presented no notable differences. The two-dimensional and three-dimensional morphometric evaluation revealed that both histologic and three-dimensional analysis showed some tendency in favour of the test group implants, however there was no statistical significance between the test and control group results.
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| 2. |
- Bougas, Kostas, et al.
(författare)
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In vivo evaluation of a novel implant coating agent : laminin-1.
- 2014
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Ingår i: Clinical Implant Dentistry and Related Research. - : Wiley Periodicals. - 1523-0899 .- 1708-8208. ; 16:5, s. 728-35
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: The aim of this study was to assess the effect of implant coating with laminin-1 on the early stages of osseointegration in vivo.MATERIALS AND METHODS: Turned titanium implants were coated with the osteoprogenitor-stimulating protein, laminin-1 (TL). Their osteogenic performance was assessed with removal torque, histomorphometry, and nanoindentation in a rabbit model after 2 and 4 weeks. The performance of the test implants was compared with turned control implants (T), alkali- and heat-treated implants (AH), and AH implants coated with laminin-1.RESULTS: After 2 weeks, TL demonstrated significantly higher removal torque as compared with T and equivalent to AH. Bone area was significantly higher for the test surface after 4 weeks, while no significant changes were detected on the micromechanical properties of the surrounding bone.CONCLUSIONS: Within the limitations of this study, our results suggest a great potential for laminin-1 as a coating agent. A turned implant surface coated with laminin-1 could enhance osseointegration comparable with a bioactive implant surface while keeping the surface smooth.
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| 3. |
- Browaeys, Hilde, et al.
(författare)
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A Retrospective Analysis of Early and Immediately Loaded Osseotite Implants in Cross-Arch Rehabilitations in Edentulous Maxillas and Mandibles Up to 7 Years
- 2013
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Ingår i: Clinical Implant Dentistry and Related Research. - : John Wiley & Sons. - 1523-0899 .- 1708-8208. ; 15:3, s. 380-389
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Tidskriftsartikel (refereegranskat)abstract
- Background: Immediate loading of full-arch restorations yields good results in selected cases, but long-term follow-up and the outcome in compromised bone are scarcely evaluated. Purpose: To evaluate immediately loaded Osseotite implants (Biomet 3i, Palm Beach, FL, USA) installed in healed or grafted bone, with regard to implant survival and peri-implant bone loss up to 7 years in function. Materials and Methods: Information was retrospectively retrieved from 83 patients' records with 749 Osseotite implants supporting immediately loaded semipermanent full-arch acrylic restorations. Five hundred sixty-eight (75.8%) implants were placed in healed bone and 181 (24.2%) in augmented bone, regenerated with sinus lifting and/or onlay/inlay grafts with/without biomaterials and membranes. Implant survival and success based on radiological peri-implant bone loss were registered. Wilcoxon rank sum tests evaluated peri-implant bone loss in compromised versus healed bone or between jaws or time intervals with p < .05 as statistically significant. Results: Sixteen of 749 implants failed (2.1%), 11/343 in maxilla (3.2%) and 5/406 (1.2%) in mandible. After 7 years, the cumulative failure rate was 9%. Mean peri-implant bone loss increased to 1.2 mm (SD 1.0) during the first 2 years but remained unchanged thereafter. Around implants in grafted bone, on average, 0.3 mm more bone loss was found. Conclusion: The Osseotite implants offer a predictable long-term outcome in terms of implant survival and stable peri-implant bone under immediate loading even in grafted bone. However, the high incidence of technical repair because of fractures of the semipermanent provisionals requires attention because it may be negative from a cost-benefit perspective. Implants in grafted bone show a tendency to a more pronounced initial bone remodeling without clinical consequence in the long term.
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| 4. |
- Browaeys, Hilde, et al.
(författare)
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Ongoing Crestal Bone Loss around ImplantsSubjected to Computer-Guided FlaplessSurgery and Immediate Loading Usingthe All-on-4® Concept
- 2015
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Ingår i: Clinical Implant Dentistry and Related Research. - : John Wiley & Sons. - 1523-0899 .- 1708-8208. ; 17:5, s. 831-843
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Tidskriftsartikel (refereegranskat)abstract
- Background: The All-on-4® concept is widely applied for full-arch rehabilitations, using two tilted and two axially loadedimplants in order to overcome anatomical constraints.Purpose: The aim of this study was to assess the survival and individual success of implants immediately loaded with anAll-on-4 full-arch screw-retained prosthetic bridge i n fully edentulous mandibles or maxillae over up to 3 years.Materials and Methods: In total, 20 patients with atrophic jaws (9 maxillae, 11 mandibles) were treated with computer-guided flapless surgery and immediately provided with a provisional bridge. The final prosthesis was delivered after6 months. In total, 80 TiUnite™ Brånemark implants were placed. Radiographs were taken after surgery and 1 and 3 yearslater.Results: A 3-year survival rate of 100% was seen for all implants, both in lower and in upper jaw. None of the temporaryor definite prostheses were lost over the follow-up period of 3 years. After 1 year, the mean bone loss was 1.13 mm (SD 0.94;range −0.1 to 3.8), and after 3 years, it was 1.61 mm (SD 1.40; range 0 to 5). The mean bone loss between the 1-year and3-year follow-ups was 0.48 mm (SD 0.66; range −1.2 to 3.6). This difference was statistically significant (p < .001), indicativeof ongoing bone loss. Twenty-six percent of the implants had bone loss above 1.5 mm after 1 year, but after 3 years, 30%of the implants had already lost more than 1.9 mm.Conclusion: The implant and prosthetic survival was 100%, and patients benefited from the All-on-4 treatment. However,unacceptable ongoing bone loss was seen in 49.2% of the patients; this may be a warning sign for future problems and needsclinical attention. Overloading and surgery-related aspects need to be investigated as potential explanations.
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| 5. |
- Browaeys, Hilde, et al.
(författare)
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The histological evaluation of osseointegration of surface enhanced microimplants immediately loaded in conjunction with sinuslifting in humans.
- 2013
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Ingår i: Clinical oral implants research. - : Wiley. - 1600-0501 .- 0905-7161. ; 24:1, s. 36-44
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: The aim was to investigate histomorphometrically whether or not implant surface nanotopography improves the bone response under immediate loading simultaneous to sinus grafting. MATERIALS AND METHODS: Dual acid-etched titanium microimplants with/without crystalline surface deposition of calcium phosphate particles were placed in bilateral sinuslift areas grafted with a mixture of iliac crest bone and BioOss. Surface topography of microimplants was characterized using interferometry. Loaded microimplants (MsL) were immobilized in a provisional bridge supported by four normal size implants. Some patients had unloaded microimplants as controls (MsU). Biopsies were trephined after 2 or 4months and histomorphometric analysis of bone area (BA) and bone-to-implant contact (BC) was performed. Nonparametric methods for dependent data were used to compare effect of surface modification, and healing time (2 vs. 4months). RESULTS: A total of 53 biopsies were available from 13 patients. A total of 4/28 and 1/11 MsL failed after resp. 2 and 4months vs. 0/6 and 1/5 MsU. Many loaded biopsies were damaged at the apical portion and showed no bone adhesion. MsL decreased in BA from coronal to apical from 2 to 4months; Coronal>Middle (P=0.047), Coronal>Apical (P<0.001) and Middle>Apical (P<0.001). This gradual decrease was not observed for BC; CoronalApical (P<0.001). Only the middle part showed significant bone contact after 2months. For MsL there was no statistically significant difference between surface or time indicating that improvement of osseointegration over time due to maturation of the graft was poor. The MsU did not show any difference between Osseotite and Nanotite for BIC and BA (P>0.05) but doubled both their BA and BIC (P<0.05) between 2 and 4months. CONCLUSIONS: Osseointegration in sinus-grafted bone mixed with BioOss was poor irrespective of healing time or nanotopographical surface modification. The apex of MsL showed minimal bone contact suggesting that the graft does not add to the loading capacity. Surface enhancement was not beneficial despite the enlarged surface area. Overloading, most critical coronally of an implant, increases risks for implant failure and jeopardizes bone healing especially under immediate loading conditions with high load.
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| 6. |
- Bryington, M. S., et al.
(författare)
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The influence of nano hydroxyapatite coating on osseointegration after extended healing periods
- 2013
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Ingår i: Dental Materials. - : Elsevier BV. - 0109-5641 .- 1879-0097. ; 29:5, s. 514-520
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Tidskriftsartikel (refereegranskat)abstract
- Objective. Studies observing early wound healing periods around dental implants demon-strate an implants ability to enhance osseointegration, the bone-implant interactions for extended healing periods though have not been thoroughly studied. Methods. Twenty threaded titanium alloy (Ti6Al4V, Grade 5) implants were inserted bilaterally, half prepared to impart stable hydroxyapatite nanoparticles onto a sand blasted and acid etched surface (HA) and half with a non-coated control surface with only heat treatment (HT), into eighteen rabbit femurs. At 12 weeks, the bone-implant blocks were retrieved for micro computed tomography (mu CT), histologic processing and histomorphometric evaluation. Results. The bone-to-implant contact for the entire threaded portion of the implant revealed 57.1% (21.0) for the HT group and 38.8% (17.7) for the HA group with a total bone area within the threads 72.5% (13.9) (HT) and 59.7% (12.5) (HA). The 3D reconstructed mu CT image corresponded to the histomorphometric results. Significance. It is suggested that multiple factors such as the change in topography and chemistry may have influenced the outcomes.
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| 7. |
- Cuellar, Jason M., et al.
(författare)
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The Effects of Amicar and TXA on Lumbar Spine Fusion in an Animal Model
- 2014
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Ingår i: Spine. - : Lippincott Williams & Wilkins. - 0362-2436 .- 1528-1159. ; 39:19, s. E1132-E1137
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Tidskriftsartikel (refereegranskat)abstract
- Study Design. Animal model. Objective. To determine whether aminocaproic acid (Amicar) and tranexamic acid (TXA) inhibit spine fusion volume. Summary of Background Data. Amicar and TXA are antifibrinolytics used to reduce perioperative bleeding. Prior in vitro data showed that antifibrinolytics reduce osteoblast bone mineralization. This study tested whether antifibrinolytics Amicar and TXA inhibit spine fusion. Methods. Posterolateral L4-L6 fusion was performed in 50 mice, randomized into groups of 10, which received the following treatment before and after surgery: (1) saline; (2) TXA 100 mg/kg; (3) TXA 1000 mg/kg; (4) Amicar 100 mg/kg; and (5) Amicar 1000 mg/kg. High-resolution plane radiography was performed after 5 weeks and micro-CT (computed tomography) was performed at the end of the 12-week study. Radiographs were graded using the Lenke scale. Micro-CT was used to quantify fusion mass bone volume. One-way analysis of variance by ranks with Kruskal-Wallis testing was used to compare the radiographical scores. One-way analysis of variance with least significant difference post hoc testing was used to compare the micro-CT bone volume. Results. The average +/- standard deviation bone volume/total volume (%) measured in the saline, TXA 100 mg/kg, TXA 1000 mg/kg, Amicar 100 mg/kg, and Amicar 1000 mg/kg groups were 10.8 +/- 2.3%, 9.7 +/- 2.2%, 13.4 +/- 3.2%, 15.5 +/- 5.2%, and 17.9 +/- 3.5%, respectively. There was a significant difference in the Amicar 100 mg/kg (P < 0.05) and Amicar 1000 mg/kg (P < 0.001) groups compared with the saline group. There was greater bone volume in the Amicar groups compared with the TXA group (P < 0.001). There was more bone volume in the TXA 1000 mg/kg group compared with TXA 100 mg/kg (P < 0.05) but the bone volume in neither of the TXA groups was different to saline (P = 0.49). There were no between-group differences observed using plane radiographical scoring. Conclusion. Amicar significantly "enhanced" the fusion bone mass in a dose-dependent manner, whereas TXA did not have a significant effect on fusion compared with saline control. These data are in contrast to prior in vitro data that antifibrinolytics inhibit osteoblast bone mineralization.
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| 8. |
- De Bruyn, Hugo, et al.
(författare)
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Radiographic evaluation of modern oral implants with emphasis on crestal bone level and relevance to peri-implant health.
- 2013
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Ingår i: Periodontology 2000. - : Wiley. - 1600-0757 .- 0906-6713. ; 62:1, s. 256-70
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Tidskriftsartikel (refereegranskat)abstract
- Implant stability and maintenance of stable crestal bone level are prerequisites for the successful long-term function of oral implants, and continuous crestal bone loss constitutes a threat to the longevity of implant-supported prosthetic constructions. The prevalence/incidence and reasons for crestal bone loss are under debate. Some authors regard infection (i.e. peri-implantitis) as the cause for virtually all bone loss, while others see crestal bone loss as an unavoidable phenomenon following surgery and implant loading. Irrespective of the cause of continuous crestal bone loss, correct usage and scientifically sound interpretation of radiographs are of utmost importance for evaluation of oral implants. The periapical radiographic technique is currently the preferred method for evaluating implant health based on bone loss, and digital radiographs allow easy standardization of the image contrast. It is suggested that baseline radiographs should be taken at the time the transmucosal part pierces the mucosal tissues and annually thereafter. The number of unreadable radiographs should be presented in scientific publications to give insights into the quality of the radiographic examination. It is suggested that not only mean values, but also the range of bone levels, should be presented to describe the proportion of implants that show continuous crestal bone loss. In the absence of other clinical symptoms, bleeding on probing around implants seems to be a weak indicator of ongoing or future loss of crestal bone. According to recent longitudinal studies on modern implant surfaces peri-implantitis defined as 'infection with suppuration associated with clinically significant progressing crestal bone loss' occurs with a prevalence of less than 5 % in implants with 10 years in function.
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| 9. |
- De Wilde, Elisabeth A. W. J., et al.
(författare)
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The soft tissue immunologic response to hydroxyapatite-coated transmucosal implant surfaces : a study in humans
- 2015
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Ingår i: Clinical Implant Dentistry and Related Research. - : John Wiley & Sons. - 1523-0899 .- 1708-8208. ; 17:S1, s. e65-e74
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Tidskriftsartikel (refereegranskat)abstract
- ObjectiveTo evaluate the soft tissue response in humans immunologically and histologically after placement of mini-implants coated with or without nano-size hydroxyapatite coatings. Material and MethodsCommercially pure (cp) titanium mini-implants (n=13) or nano-hydroxyapatite-coated ones (n=12) were randomly placed into partially edentulous jaws. Crevicular fluid was sampled 1week after placement and subjected to quantitative polymerase chain reaction analysis to explore the inflammatory markers. After 8weeks, implants and surrounding soft and hard tissue were trephined, and undecalcified ground sections were prepared. Inflammatory cell accumulation within a defined region of interest in the soft tissue was quantified histomorphometrically. ResultsNo statistically significant differences in immunological response to the different implant surfaces were found for IL-6 (p=.438), TGF-2 (p=.467), MMP-8 (p=.758), CCL-3 (p=.758), IL-8 (p=.771), and IL-1 (0.771). Histomorphometric evaluation presented no statistically significant difference between the two mini-implant surfaces with regards to number of inflammatory cells (p=.669). ConclusionNano-hydroxyapatite-coated surfaces in the transmucosal region yielded similar inflammatory response and is suggested to be as biocompatible as commercially pure titanium surfaces.
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| 10. |
- Dierens, Melissa, et al.
(författare)
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Alterations in soft tissue levels and aesthetics over a 16–22 year period following single implant treatment in periodontally-healthy patients : a retrospective case series
- 2013
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Ingår i: Journal of Clinical Periodontology. - : John Wiley & Sons. - 0303-6979 .- 1600-051X. ; 40:3, s. 311-318
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Tidskriftsartikel (refereegranskat)abstract
- Purpose Long term studies on single implants are scarce and merely focus on clinical response parameters, complications and bone remodelling. The objective of this retrospective case series was to assess alterations in soft tissue levels and aesthetics over a 16–22 year period in periodontally-healthy patients. Material and methods Patients who had received a single turned implant in the anterior maxilla/mandible at the Dental Specialist Clinic in Malmö between 1987 and 1993 were invited for a re-examination on the basis of a number of inclusion criteria. Both neighbouring teeth had to be present at re-examination and baseline clinical photographs (within the first year of function) had to be available for soft tissue evaluation. These photographs were superimposed onto final clinical photographs to assess longitudinal soft tissue alterations. Results Twenty-one patients (nine females; mean age 23, range 16–41) treated with 24 single implants met the criteria for soft tissue evaluation. Peri-implant soft tissue levels (papillae, midfacial level) remained stable over a 16–22 year observation period (p ≥ 0.372). However, neighbouring teeth demonstrated midfacial recession and eruption pointing to a major distortion with the implant crown (> 1 mm) in 5/24 (21%) and 10/24 (42%) of the cases, respectively. Baseline aesthetics was considered poor (mean Pink Esthetic Score 7.42, mean White Esthetic Score 5.43), yet a significant time effect could not be demonstrated (p ≥ 0.552). Implant and tooth bone loss was low (mean 0.6 mm and 0.4 mm, respectively) over a 16–22 year period. Conclusions This limited case series demonstrated stable peri-implant soft tissue levels and aesthetics in the long term following single implant treatment in periodontally-healthy patients. However, midfacial recession and eruption may be expected at neighbouring teeth.
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