| 71. |
- Meirelles, Luiz, 1974, et al.
(författare)
-
The effect of chemical and nano topographical modifications on early stage of osseointegration
- 2008
-
Ingår i: The International Journal of Oral & Maxillofacial Implants. - 0882-2786. ; 23:4, s. 641-7
-
Tidskriftsartikel (refereegranskat)abstract
- Purpose: To investigate the effect of chemically modified implants with similar micro but different nano topography on early stage of osseointegration. Materials and Methods: Screw shaped implants were placed in the flat proximal medial tibial methaphyses of 10 New Zealand white rabbits. Blasted (control); blasted-fluoride and blasted-nano HA implants were investigated. Surface evaluation included chemical analyses with x-ray photoelectron spectroscopy, morphological analyses with scanning electron microscopy and topographical analyses with interferometry. Bone response was investigated with removal torque measurements and histological analyses after a healing period of 4 weeks. Results: Chemical analyses revealed the presence of Ti, O, C and N in all implant groups. The blasted-F group revealed F and the blasted nano HA group Ca and P with simultaneous decrease of Ti and O. Surface roughness parameters showed a slight decrease of the average height deviation for the blasted nano-HA and blasted-F compared to the blasted control implants. SEM images at high magnification indicated the presence of nano structures on the chemically modified implants. Removal torque (RTQ) mean values revealed an increase of 17% to 25% for the chemically modified implants compared to the control implants and the histological analyses demonstrated a similar enhanced bone formation to the chemically modified implants with nanostructures. Conclusion: Chemical modifications used in the present study were capable of producing a unique nano topography and together with the ions present at the implant surface may explain the increased RTQ and histomorphometric values after a healing period of 4 weeks.
|
|
| 72. |
- Milleret, V., et al.
(författare)
-
Rational design and in vitro characterization of novel dental implant and abutment surfaces for balancing clinical and biological needs
- 2019
-
Ingår i: Clinical Implant Dentistry and Related Research. - : Wiley. - 1523-0899 .- 1708-8208. ; 21, s. 15-24
-
Tidskriftsartikel (refereegranskat)abstract
- Background Long-term success and patient satisfaction of dental implant systems can only be achieved by fulfilling clinical as well as biological needs related to maintenance, aesthetics, soft tissue sealing, and osseointegration, among others. Surface properties largely contribute to the biological and clinical performance of implants and abutments. Purpose To decipher the clinical and biological needs in implant dentistry. To address identified needs, next-generation dental implant and abutment surfaces are designed and characterized in vitro. Materials and Methods Novel implant and abutment surface designs were produced and characterized using surface chemical analysis, surface topography analysis, scanning electron microscopy, contact-angle measurements, and cell-culture experiments. Results The novel anodized implant surface was gradually anodized, increasing the surface roughness, surface enlargement, and oxide-layer thickness from platform to apex. The surface was phosphorus enriched, nonporous, and nanostructured at the collar, and showed micropores elsewhere. The novel anodized abutment surface was smooth, nanostructured, nonporous, and yellow. Pristine surfaces with high density of hydroxyl-groups were protected during storage using a removable cell-friendly layer that allowed dry packaging. Conclusions A novel anodized implant system was developed with surface chemistry, topography, nanostructure, color, and surface energy designed to balance the clinical and biological needs at every tissue level.
|
|
| 73. |
|
|
| 74. |
- Mustafa, Kamal, et al.
(författare)
-
The influence of surface topography of ceramic abutments on the attachment and proliferation of human oral fibroblasts.
- 2005
-
Ingår i: Biomaterials. - : Elsevier BV. - 0142-9612. ; 26:4, s. 373-81
-
Tidskriftsartikel (refereegranskat)abstract
- As different implant abutments are introduced to obtain a sufficient soft tissue barrier, the aim of this study was to determine the effect of three different surface modifications of densely sintered high-purity aluminium oxide on morphology, attachment and proliferation of human gingival fibroblasts. Fibroblasts were cultured on pressed aluminium oxide, milled, and then sintered to full density (1), on pressed, densely sintered (2), and on pressed, densely sintered and then polished surfaces (3). The different surfaces were analyzed using a confocal laser scanner, an atomic force microscope and a scanning electron microscope. The cell profile areas were measured using a semiautomatic interactive image analyzer and the figures were expressed as percent of attachment. The polished specimens had the smoothest surfaces and the roughest were the milled surfaces in terms of height deviation. No difference was found in the spacing between the peaks on the polished surfaces compared to the milled surfaces. Fibroblasts on the milled ceramic appeared to follow the direction of the fine irregularities on the surface. The analyses showed the polished surfaces had significantly higher percentages of initial cell attachment than the other surfaces (P < 0.05). After 3 days of cell culture, significantly more cells were attached to the milled and sintered surfaces than to the polished one, possibly indicating higher proliferation capacity on those types of surfaces.
|
|
| 75. |
- Nilsson, Andree, et al.
(författare)
-
Infraposition of anterior maxillary implant-supported single-tooth restorations in adolescent and adult patients-A prospective follow-up study up to 6 years
- 2019
-
Ingår i: Clinical Implant Dentistry and Related Research. - : John Wiley & Sons. - 1523-0899 .- 1708-8208. ; 21:5, s. 953-959
-
Tidskriftsartikel (refereegranskat)abstract
- Background In the maxillary incisor area infraposition of implant restorations can be an esthetic problem. Purpose The aim was to analyze the prevalence of infraposition of single-tooth implant restorations in the anterior maxilla in adolescent and adult patients. Material and Methods The study comprised of 31 patients, 18 women and 13 men, with 39 restorations and with a mean and median age of 23.8 and 18.8 years, range 17.8 to 52.8 years, at the time of implant crown connection. The mean and median time in function for the restorations was 4.5 and 4.3 years respectively with a range of 3.3 to 6.6 years. Results Twenty restorations 51%, showed no signs of infraposition. A slight infraposition (<0.5 mm) was seen in 36% of the restorations. Only in one patient, the observed infraposition of the implant crown was more than 1 mm. We found no significant difference of the observed level of vertical infraposition, Score A (0 mm) and Score B (<0.5 mm), in subjects where the restoration was placed before the age of 20 years compared to the older patients. There were no significant differences in changes of the vertical infraposition when comparing different parameters such as age, gender, jaw relation (Angle-classes I-III), overbite/overjet, occlusal contact on the implant crown, bone augmentation before or at implant installation or if orthodontic treatment of the neighboring teeth had been made before or after the implant installation. Conclusions In the present study, there was a significant yet low correlation between the observed vertical infraposition of the single-tooth implant restoration and the subject's evaluation of the esthetics of the restoration (VAS). Fifty-one percent of the implant-supported crowns, showed no signs of vertical infraposition. A slight infraposition (< 0.5 mm) was however seen in 36% of the restorations. Only one crown showed a vertical infraposition of more than 1 mm.
|
|
| 76. |
- Olander, Julia, 1984, et al.
(författare)
-
Implant-Supported Single Crowns with Titanium or Zirconia Abutments: A Retrospective Up-to-5-year Follow-up Study.
- 2022
-
Ingår i: The International journal of prosthodontics. - : Quintessence Publishing. - 1942-4426 .- 0893-2174. ; 35:4, s. 387-395
-
Tidskriftsartikel (refereegranskat)abstract
- To compare the clinical outcomes of single implants with titanium (Ti) or zirconia (Zr) abutments after up to 5 years in function.This study was a retrospective analysis on single implants with screw-retained abutments (Zr or Ti) covered with porcelain veneer placed between 2011 and 2013 at one referral specialist clinic. Clinical data from patient records were collected from 132 patients and 174 implants. Technical complications such as fractures, chipping, and abutment screw loosening were registered. Radiographs were analyzed comparing both annual bone loss and accumulated bone loss at 5 years. In 57 patients with 85 implants, the values of accumulated bone loss at 5 years were compared to baseline.Technical complications occurred in 16 (9%) of the implants, most often during the first year. The following complications were found: fracture of the abutment (n = 1); loosening of the abutment screws (n = 5); and chipping of the porcelain veneer (n = 11). Ti abutments had more complications than Zr abutments (79%). Of all the implants, 45% had an annual bone loss ranging between 0.05 and 2.15 mm, and 59% had an accumulated bone loss at 5 years ranging between 0.05 and 4.25 mm. Zr abutments had a statistically significantly higher amount of yearly and accumulated bone loss at 5 years.Abutment material affected marginal bone loss. The Zr group displayed statistically more bone loss both yearly and after 5 years compared to the Ti group. Technical complications were not affected by abutment material but were affected by age of the patient.
|
|
| 77. |
- Olander, Julia, 1984, et al.
(författare)
-
Inflammatory Gene Profile and Particle Presence in Peri-Implant Mucosa: a Pilot Study on 9 Patients
- 2023
-
Ingår i: Jomr-Journal of Oral & Maxillofacial Research. - 2029-283X. ; 14:3
-
Tidskriftsartikel (refereegranskat)abstract
- Objectives: The purpose of this pilot study is to compare gene expression in mucosa around dental implants with zirconia abutment to titanium and investigate presence of particles in mucosa samples and on implant heads. Material and Methods: Ten patients with a single implant supported prosthesis connected to zirconia or titanium abutments were invited at the five-year control. A clinical examination and a survey on experience of function and appearance were conducted. A mucosa biopsy taken in close vicinity to the implant were analysed by real-time polymerase chain reaction (qPCR) and presence of particles in a scanning electron microscope/energy-dispersive X-ray spectroscope (SEM/EDX). Cytological smear samples were collected and analysed through inductively coupled plasma mass spectrometry (ICP-MS) to investigate presence of particles on implant heads. Results: In total, 9 patients participated in the study, five with titanium abutments and four with zirconia abutments. All patients were satisfied with function and aesthetics. Titanium and iron particles were detected in mucosa biopsies. The ICP -MS analysis demonstrated presence of zirconia and titanium. Several proinflammatory genes were upregulated in the zirconia abutment group. Conclusions: Around zirconia abutments a slight increase in proinflammatory response and amount of wear particles was seen as compared to titanium. Wear particles of titanium were present in all soft tissue samples, however zirconia particles only in the samples from implants heads/mucosa with zirconia abutments.
|
|
| 78. |
- Olander, Julia, 1984, et al.
(författare)
-
Wear particle release at the interface of dental implant components: Effects of different material combinations. An in vitro study
- 2022
-
Ingår i: Dental Materials. - : Elsevier BV. - 0109-5641. ; 38:3, s. 508-516
-
Tidskriftsartikel (refereegranskat)abstract
- Objectives: Particle generation from implant components caused by frictional wear affect the surrounding peri-implant tissues. The objective of this study was to evaluate the effect of combining implant and abutment materials on wear and particle release in a dynamical loading setup. Methods: A customized dynamical loading machine was used to subject two implant materials (Titanium and Titanium- Zirconium alloy) paired with two different abutment materials (Titanium and Zirconia) to a cyclic loading set of 240.000 cycles (simulating 1 year of clinical use). The implant and abutment complex was immersed in corrosive liquid to collect particle debris and measure the release of corroded ions. Scanning electron microscopy was used to analyze signs of wear on the components after testing and evaluate the size and composition of particle debris. Results: Wear signs were evident in all material couplings. Particle debris was found on top, inside the implants, and on the abutment heads. The particle size ranged between 0.6 and 16.9 µm, with larger particles composed of Ti. Smaller-sized particles were found in the container liquid ranging from 0.253 to 1.7 µm compared to inside the implants ranging from 3.25 to 95.3 µm. Larger particles were found inside Tizr implants compared to Ti implants. Low levels of ions released due to corrosion were found when measuring content in surrounding liquid. Significance: Particle generation is evident when subjecting dental implant and abutment couplings in a dynamic loading setup. Internally connected implants hinder the release of larger particles to surrounding container liquid. © 2022 The Authors
|
|
| 79. |
- Peruzzi, Niccolò, et al.
(författare)
-
Multimodal ex vivo methods reveal that Gd-rich corrosion byproducts remain at the implant site of biodegradable Mg-Gd screws
- 2021
-
Ingår i: Acta Biomaterialia. - : Elsevier. - 1742-7061 .- 1878-7568. ; 136, s. 582-591
-
Tidskriftsartikel (refereegranskat)abstract
- Extensive research is being conducted on magnesium (Mg) alloys for bone implant manufacturing, due to their biocompatibility, biodegradability and mechanical properties. Gadolinium (Gd) is among the most promising alloying elements for property control in Mg alloy implants; however, its toxicity is controversial. Investigating Gd behavior during implant corrosion is thus of utmost importance. In this study, we analyzed the degradation byproducts at the implant site of biodegradable Mg-5Gd and Mg-10Gd implants after 12 weeks healing time, using a combination of different imaging techniques: histology, energy-dispersive x-ray spectroscopy (EDX), x-ray microcomputed tomography (µCT) and neutron µCT. The main finding has been that, at the healing time in exam, the corrosion appears to have involved only the Mg component, which has been substituted by calcium and phosphorus, while the Gd remains localized at the implant site. This was observed in 2D by means of EDX maps and extended to 3D with a novel application of neutron tomography. X-ray fluorescence analysis of the main excretory organs also did not reveal any measurable accumulation of Gd, further reinforcing the conclusion that very limited or no removal at all of Gd-alloy happened during degradation.
|
|
| 80. |
- Qian, Jie, et al.
(författare)
-
Reasons for Marginal Bone Loss around Oral Implants
- 2012
-
Ingår i: Clinical Implant Dentistry and Related Research. - : Wiley. - 1523-0899 .- 1708-8208. ; 14:6, s. 792-807
-
Tidskriftsartikel (refereegranskat)abstract
- Background The reasons for long-term marginal bone loss around oral implants are not well understood. Purpose The aim of this paper is to analyze presented evidence behind anticipated reasons for long-term marginal bone loss around oral implants. Materials and Methods A computerized research was conducted on PubMed in April 2011 with the following keywords: oral implants and marginal bone resorption/crestal bone loss/bone loss/bone resorption. This search resulted in a total of one thousand one hundred ninety-four papers of which seven hundred fifty-three were clinical contributions. Further search and filtering finally resulted in 21 experimental studies and one hundred sixteen clinical studies, which were reviewed. Results No evidence was found that primary infection caused marginal bone resorption. Clinical papers that have reported high levels of peri-implantitis were not supported by data given. Clinical evidence was presented that the so-called combined factors (implant hardware, clinical handling, and patient characteristics) may lead to marginal bone resorption. However, once tissue damage has been caused by combined factors, inflammation and/or infection may develop secondarily and then result in peri-implantitis that may need particular clinical treatment. Conclusions As marginal bone loss primarily depends on numerous background factors, it seems logical that, for example, the use of poorly constructed implants placed and handled by untrained clinicians may result in high numbers of patients with secondary problems in form of peri-implantitis; having said this, control of combined factors may likewise lead to very good clinical results where peri-implantitis would represent a very rare disease indeed even at follow-up times of 10 years or more.
|
|
