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1.
Sci Rep ; 13(1): 16753, 2023 10 05.
Article in English | MEDLINE | ID: mdl-37798324

ABSTRACT

Intradialytic hypotension and arrhythmias are complications of hemodialysis. They are associated with decreased intravascular volume due to reduced ultrafiltration volume, cardiac function, and arterial tone. The vascular endothelial glycocalyx, which exists on the surface of healthy vascular endothelial cells and maintains vascular permeability, has been suggested to be impaired by hemodialysis. This single-center retrospective study evaluated the association between syndecan-1, an endothelial glycocalyx dysfunction marker, and complications of hemodialysis. We enrolled 92 patients who underwent outpatient hemodialysis at Gifu Seiryu Hospital from April to July 2022 (346 hemodialysis sessions). The median duration and time of hemodialysis were 40 months and 4.1 h, respectively. Median serum syndecan-1 levels were 67.7 ng/mL before and 98.3 ng/mL after hemodialysis. Hemodialysis complications were noted in 68 sessions, all of which were hypotension. No correlation between pre-hemodialysis syndecan-1 levels and the incidence of complications was observed. However, a positive correlation between the amount of change in syndecan-1 levels before and after hemodialysis and the incidence of hemodialysis complications was noted. Conversely, syndecan-1 levels did not correlate with brain or atrial natriuretic peptides, suggesting that impairment of the vascular endothelial glycocalyx may be a possible cause of intradialytic hypotension and may be useful in preventing intradialytic hypotension.


Subject(s)
Hypotension , Syndecan-1 , Humans , Retrospective Studies , Endothelial Cells , Renal Dialysis/adverse effects , Hypotension/etiology
2.
J Oral Implantol ; 49(4): 382-387, 2023 Aug 01.
Article in English | MEDLINE | ID: mdl-36796076

ABSTRACT

Oral reconstruction in fully edentulous patients can be challenging at times. Hence, it is important to offer the most suitable treatment option after a detailed clinical examination and treatment plan. This 14-year long-term follow-up report is the clinical case of a 71-year-old nonsmoker who visited the clinic in 2006 and opted for full-mouth reconstruction using Auro Galvano crown (AGC) attachments. Maintenance was performed twice a year for the past 14 years, and the clinical results were satisfactory, with no signs of inflammation or lack of retention of the superstructures. This was associated with a high level of patient satisfaction, as indicated by the Oral Health Impact Profile. Compared to the screw-retained implants over dentures, AGC attachments can be a viable and effective treatment option when restoring fully edentulous arches.


Subject(s)
Dental Implants , Jaw, Edentulous , Mouth, Edentulous , Humans , Aged, 80 and over , Aged , Jaw, Edentulous/surgery , Dental Implantation, Endosseous/methods , Treatment Outcome , Mouth, Edentulous/surgery , Dental Prosthesis, Implant-Supported/methods , Follow-Up Studies
3.
J Esthet Restor Dent ; 34(8): 1166-1178, 2022 12.
Article in English | MEDLINE | ID: mdl-36239133

ABSTRACT

OBJECTIVE: To investigate the effect of calcium hydroxide intracanal medicament on the push-out bond strength of resin-based and calcium silicate-based endodontic sealers. METHODS: A comprehensive search of was conducted for all relevant in-vitro studies. All randomized controlled in-vitro studies that evaluated the effect of calcium hydroxide on the push-out bond strength of resin-based or calcium silicate-based endodontic sealers were assessed. The variables of interest were extracted, and the risk of the included studies was evaluated. The standardized mean difference was calculated and the significance level was set at p value <0.05. RESULTS: A total of 26 studies were eligible for analysis. There were 45 independent comparison groups and 1009 recruited teeth. The pooled data showed no significant difference in push-out bond strength between calcium hydroxide and control group in the resin-based group (SMD = 0.03; 95% CI = -0.55, 0.60; p = 0.93), and calcium silicate-based group (SMD = 0.02; 95% CI = -0.31, 0.35; p = 0.90). Most of the studies (21 out of 26) were at medium risk of bias and five studies showed a low risk of bias. CONCLUSION: The available evidence suggests that calcium hydroxide used as intracanal medication does not influence the push-out bond strength of the resin- and calcium silicate-based endodontic sealers. CLINICAL SIGNIFICANCE: The results of this meta-analysis suggest that calcium hydroxide used as intracanal medication does not influence the push-out bond strength of resin-based and calcium silicate-based endodontic sealers.


Subject(s)
Dental Bonding , Root Canal Filling Materials , Calcium Hydroxide/chemistry , Root Canal Filling Materials/chemistry , Dental Bonding/methods , Materials Testing
4.
Article in English | MEDLINE | ID: mdl-35353090

ABSTRACT

Implant therapy for tooth loss in the molar area is challenging due to the anatomical limitations, requiring bone augmentation procedures that are associated with high surgical complexity and long postsurgical recovery. Recently, many studies have demonstrated the usefulness of short implants. However, few studies have been performed in Japanese patients to evaluate peri-implant bone changes, changes in peri-implant epithelial tissue, and patient satisfaction. The present study included 16 patients (5 men, 11 women; mean age: 60 years) who received 26 short (6-mm) implants. Changes in peri-implant bone and epithelial tissue were measured radiographically at superstructure loading and after 2 years. Peri-implant pocket probing depth was measured at the epithelial tissue and compared at both time points. Patient satisfaction was graded using the Oral Health Impact Profile (OHIP-14) before treatment and at follow-up. The mean mesial and distal bone levels were -0.05 mm and 0.37 mm at loading, respectively, and were 0.33 mm and 0.53 mm after 2 years, respectively. Significant peri-implant bone formation for mesial and distal bone levels at both time points were determined by Wilcoxon signed-rank test. Mean probing depth increased slightly, from 3.03 mm at loading to 3.33 mm after 2 years, but no significant difference was found. The OHIP-14 found that patient satisfaction levels increased after 2 years. Using 6-mm short implants in sites with insufficient bone levels can be a highly beneficial treatment option for patients, as it avoids the need for bone augmentation. However, more long-term and detailed studies on the clinical outcomes for these implants are required.


Subject(s)
Dental Implants , Patient Satisfaction , Dental Implantation, Endosseous , Dental Prosthesis Design , Female , Follow-Up Studies , Humans , Japan , Male , Middle Aged , Retrospective Studies
5.
Article in English | MEDLINE | ID: mdl-30794262

ABSTRACT

This study investigated the level of magnetic energy around implants possessing a static magnetic field (SMF) and assessed the in vivo influence of SMF on bone regeneration. Implants possessing a sintered neodymium magnet internally were placed in a rabbit femur. An implant without SMF was placed as control. After 12 weeks of healing in vivo, the bone samples were subjected to histologic/histomorphometric evaluation. The bone-to-implant contact for the test group and the control group were 32.4 ± 13.6% and 17.1 ± 4.5%, respectively, and the differences were statistically significant (P < .05). The results suggested that the SMF promoted new bone apposition.


Subject(s)
Femur/growth & development , Magnetic Fields , Osteogenesis/radiation effects , Animals , Dental Implantation, Endosseous/methods , Femur/radiation effects , Femur/surgery , Rabbits
6.
Clin Oral Implants Res ; 29(7): 707-715, 2018 Jul.
Article in English | MEDLINE | ID: mdl-29781224

ABSTRACT

OBJECTIVE: The aim of this study was to investigate the extent of cortical bone remodeling between two different drilling protocols by means of histomorphometric, µ-CT, and biomechanical analyses. MATERIAL AND METHODS: A total of 48 implants were inserted into the mandible of six sheep following two drilling protocols: Group A (Test, n = 24), undersized preparation; Group B (Control, n = 24), non-undersized preparation. The animals were euthanatized to obtain 5 and 10 weeks of implantation time. Removal torque (RTQ) was measured on 12 implants of each group and the peri-implant bone was µ-CT scanned. Bone volume density (BV/TV) was calculated in pre-determined cylindrical volumes, up to 1.5 mm from implant surface. Non-decalcified histology was prepared on the remaining 12 implants from each group, where total bone-to-implant contact (totBIC) and newly-formed BIC (newBIC) was measured. Bone Area Fraction Occupancy (BAFO) was determined in pre-determined areas up to 1.5 mm from implant surface. Paired sample t test or Wilcoxon signed-rank test was used to investigate differences between the groups. RESULTS: Group A presented significantly increased RTQ value at 5 weeks, while no difference was observed at 10 weeks. Group B presented increased BV/TV value at 5 weeks. Both groups showed comparable values for totBIC at both time-points. However, Group A presented significantly lower newBIC at 5 weeks. Higher BAFO was observed in Group B at 5 weeks. CONCLUSIONS: Implants inserted into undersized sites has an increased biomechanical performance, but provoked major remodeling of the cortical bone during the early healing period compared to non-undersized preparations. After 10 weeks, no difference was observed.


Subject(s)
Cortical Bone/surgery , Dental Implantation, Endosseous/methods , Mandible/surgery , Animals , Biomechanical Phenomena , Bone Remodeling , Cortical Bone/anatomy & histology , Cortical Bone/diagnostic imaging , Female , Mandible/anatomy & histology , Mandible/diagnostic imaging , Osseointegration , Sheep , Torque , X-Ray Microtomography
7.
J Biomed Mater Res B Appl Biomater ; 106(1): 201-208, 2018 Jan.
Article in English | MEDLINE | ID: mdl-28067984

ABSTRACT

This study evaluated the sustained release effect of clarithromycin-loaded in PLGA microspheres in a rabbit calvaria defect model. Four bone defects (ø5.0) were created in the calvaria of New Zealand White rabbits (n = 21, n = 7/time point). The defects were randomly designated to four groups. Group 1: No augmentation (sham), Group 2: beta-tricalcium phosphate (ß-TCP), Group 3: ß-TCP with 0.12 µg clarithromycin, and Group 4: ß-TCP with 6.12 µg PLGA microspheres loaded with 0.12 µg Clarithromycin. After 2, 4, and 12 weeks of healing, bone regeneration was evaluated using micro-computed tomography (µCT) and histology. Clarithromycin release from PLGA microspheres revealed sustained release for around 4 weeks with ∼50% release during the first week. Histologically, new bone formation was evident at 2 and 4 weeks of healing in all groups and bone formation increased as a function of healing time. At 12 weeks, Group 4 showed significantly higher amount of newly formed bone compared to Group 1. The µCT showed that Group 4 expressed significantly higher bone formation compared to Group 1 at all time points. The in vivo findings showed that ß-TCP with clarithromycin-loaded microspheres can enhance bone formation in bone defects. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 201-208, 2018.


Subject(s)
Bone Regeneration/drug effects , Clarithromycin , Lactic Acid , Microspheres , Polyglycolic Acid , Skull , Animals , Clarithromycin/chemistry , Clarithromycin/pharmacokinetics , Clarithromycin/pharmacology , Delayed-Action Preparations/chemistry , Delayed-Action Preparations/pharmacokinetics , Delayed-Action Preparations/pharmacology , Lactic Acid/chemistry , Lactic Acid/pharmacokinetics , Lactic Acid/pharmacology , Polyglycolic Acid/chemistry , Polyglycolic Acid/pharmacokinetics , Polyglycolic Acid/pharmacology , Polylactic Acid-Polyglycolic Acid Copolymer , Rabbits , Skull/injuries , Skull/metabolism , Skull/pathology
8.
J Prosthodont ; 27(7): 665-669, 2018 Aug.
Article in English | MEDLINE | ID: mdl-28901663

ABSTRACT

PURPOSE: To evaluate the antifungal activity and mechanical properties of a novel antifungal tissue conditioner containing Juncus powder. MATERIALS AND METHODS: Juncus powder was mixed with GC tissue conditioner at concentrations of 2.5%, 5.0%, and 10.0% by mass. The cylindrical specimens of Juncus-mixed tissue conditioner (dimensions: 10 mm in diameter and 2 and 6 mm in height for antimicrobial and mechanical tests, respectively) were prepared. The specimens placed on the bottom of the 24-well tissue culture plate were cultured with Candida albicans CAD1 for 2 and 4 days. The proliferation of the C. albicans in the wells was determined by measuring the optical density of fungal culture, and the surface of the specimens were also observed by scanning electron microscopy (SEM). To assess the mechanical properties of the specimens, the fluidity and hardness of Juncus-mixed tissue conditioner were measured using the methods certified according to ISO 10139-1. RESULTS: Juncus-mixed tissue conditioner significantly exhibited growth inhibitory effect in a Juncus concentration-dependent manner after both 2- and 4- day cultures. SEM observation showed that the amount of C. albicans on Juncus-mixed specimens drastically decreased, and biofilm formation was markedly inhibited. Moreover, both mechanical properties were found to be within the ranges regulated and specified by ISO. CONCLUSION: These findings demonstrated that the tissue conditioner including Juncus powder has a significant growth inhibitory effect against C. albicans, and it is suggested that the application of Juncus-mixed tissue conditioner may prevent denture stomatitis and oral candidiasis in denture wearers.


Subject(s)
Antifungal Agents/pharmacology , Candida albicans/drug effects , Magnoliopsida , Plant Extracts/pharmacology , Tissue Conditioning, Dental/methods , Biofilms/drug effects , Cell Proliferation/drug effects , In Vitro Techniques , Microscopy, Electron, Scanning
9.
Materials (Basel) ; 10(12)2017 Dec 08.
Article in English | MEDLINE | ID: mdl-29292788

ABSTRACT

Phosphoric acid-etching treatment to the hydroxyapatite (HA) surface can modify the solubility calcium structure. The aim of the present study was to develop phosphate treated porous HA, and the characteristic structures and stimulation abilities of bone formation were evaluated to determine its suitability as a new type of bone graft material. Although the phosphoric acid-etching treatment did not alter the three-dimensional structure, a micrometer-scale rough surface topography was created on the porous HA surface. Compared to porous HA, the porosity of phosphate treated porous HA was slightly higher and the mechanical strength was lower. Two weeks after placement of the cylindrical porous or phosphate treated porous HA in a rabbit femur, newly formed bone was detected in both groups. At the central portion of the bone defect area, substantial bone formation was detected in the phosphate treated porous HA group, with a significantly higher bone formation ratio than detected in the porous HA group. These results indicate that phosphate treated porous HA has a superior surface topography and bone formation abilities in vivo owing to the capacity for both osteoconduction and stimulation abilities of bone formation conferred by phosphoric acid etching.

10.
Clin Oral Implants Res ; 28(10): 1234-1240, 2017 Oct.
Article in English | MEDLINE | ID: mdl-27531124

ABSTRACT

OBJECTIVES: Titanium-zirconium (TiZr) has been proposed as a mechanically stronger alternative to commercially pure titanium for oral and orthopaedic implants. However, not much is known on the osseointegration kinetics of TiZr surfaces. In this study, we aimed to identify the genetic response of bone around TiZr implants compared to pure Ti. MATERIAL AND METHODS: Microtextured and hydrophilic TiZr implants (tests) and cpTi implants grade IV (controls) were placed in the tibia of 30 New Zealand white rabbits. At 2, 4 and 12 weeks, the implants were subjected to removal torque test (RTQ). The expression of a panel of genes involved in the process of osseointegration was measured in the bone around the test and control implants by means of quantitative real-time polymerase chain reaction (PCR) and compared to the control samples. RESULTS: The controls yielded statistically significant higher RTQ at 4 weeks, but the RTQ of the tests had a larger increase between 4 and 12 weeks, when both groups reached similar values. The gene expression analysis showed that all selected markers for bone formation, bone remodelling and cytokines were significantly upregulated around TiZr implants after 2 weeks. After 4 weeks of healing, two bone formation markers were significantly more expressed in the test samples, while at 12 weeks, the expression of all genes was similar in the two groups. CONCLUSIONS: TiZr implants showed comparable biomechanical outcomes to cpTi up to 12 weeks of healing. However, at early healing stages, they showed a significant upregulation of osteogenesis and osteoclastogenesis markers.


Subject(s)
Dental Implants , Dental Prosthesis Design , Osseointegration/physiology , Titanium , Zirconium , Animals , Female , Materials Testing , Rabbits , Signal Transduction , Time Factors , Titanium/chemistry , Zirconium/chemistry
11.
J Mech Behav Biomed Mater ; 61: 581-589, 2016 08.
Article in English | MEDLINE | ID: mdl-27148637

ABSTRACT

The prosthetic applications of titanium have been challenging because titanium does not possess suitable properties for the conventional casting method using the lost wax technique. We have developed a production method for biomedical application of porous titanium using a moldless process. This study aimed to evaluate the physical and mechanical properties of porous titanium using various particle sizes, shapes, and mixing ratio of titanium powder to wax binder for use in prosthesis production. CP Ti powders with different particle sizes, shapes, and mixing ratios were divided into five groups. A 90:10wt% mixture of titanium powder and wax binder was prepared manually at 70°C. After debinding at 380°C, the specimen was sintered in Ar at 1100°C without a mold for 1h. The linear shrinkage ratio of sintered specimens ranged from 2.5% to 14.2%. The linear shrinkage ratio increased with decreasing particle size. While the linear shrinkage ratio of Groups 3, 4, and 5 were approximately 2%, Group 1 showed the highest shrinkage of all. The bending strength ranged from 106 to 428MPa under the influence of porosity. Groups 1 and 2 presented low porosity followed by higher strength. The shear bond strength ranged from 32 to 100MPa. The shear bond strength was also particle-size dependent. The decrease in the porosity increased the linear shrinkage ratio and bending strength. Shrinkage and mechanical strength required for prostheses were dependent on the particle size and shape of titanium powders. These findings suggested that this production method can be applied to the prosthetic framework by selecting the material design.


Subject(s)
Prostheses and Implants , Titanium/chemistry , Materials Testing , Particle Size , Porosity
12.
Int J Nanomedicine ; 11: 1435-42, 2016.
Article in English | MEDLINE | ID: mdl-27103801

ABSTRACT

Polyether ether ketone (PEEK) possesses excellent mechanical properties similar to those of human bone and is considered the best alternative material other than titanium for orthopedic spine and trauma implants. However, the deficient osteogenic properties and the bioinertness of PEEK limit its fields of application. The aim of this study was to limit these drawbacks by coating the surface of PEEK with nano-scaled hydroxyapatite (HA) minerals. In the study, the biological response to PEEK, with and without HA coating, was investigated. Twenty-four screw-like and apically perforated implants in the rabbit femur were histologically evaluated at 3 weeks and 12 weeks after surgery. Twelve of the 24 implants were HA coated (test), and the remaining 12 served as uncoated PEEK controls. At 3 weeks and 12 weeks, the mean bone-implant contact was higher for test compared to control (P<0.05). The bone area inside the threads was comparable in the two groups, but the perforating hole showed more bone area for the HA-coated implants at both healing points (P<0.01). With these results, we conclude that nano-sized HA coating on PEEK implants significantly improved the osteogenic properties, and in a clinical situation this material composition may serve as an implant where a rapid bone fusion is essential.


Subject(s)
Coated Materials, Biocompatible/pharmacology , Durapatite/pharmacology , Femur/anatomy & histology , Implants, Experimental , Ketones/pharmacology , Nanoparticles/chemistry , Osseointegration/drug effects , Polyethylene Glycols/pharmacology , Animals , Benzophenones , Femur/drug effects , Imaging, Three-Dimensional , Particle Size , Polymers , Rabbits
13.
Biomed Mater ; 11(1): 015012, 2016 Feb 02.
Article in English | MEDLINE | ID: mdl-26836201

ABSTRACT

Porous titanium has long been desired as a bone substitute material because of its ability to reduce the stress shielding in supporting bone. In order to achieve the various pore structures, we have evolved a moldless process combined with a space holder technique to fabricate porous titanium. This study aims to evaluate which pore size is most suitable for bone regeneration using our process. The mixture comprising Ti powder, wax binder and PMMA spacer was prepared manually at 70 °C which depended on the mixing ratio of each group. Group 1 had an average pore size of 60 µm, group 2 had a maximum pore size of 100 µm, group 3 had a maximum pore size of 200 µm and group 4 had a maximum pore size of 600 µm. These specimens were implanted into rabbit calvaria for three and 20 weeks. Thereafter, histomorphometrical evaluation was performed. In the histomorphometrical evaluation after three weeks, the group with a 600 µm pore size showed a tendency to greater bone ingrowth. However, after 20 weeks the group with a pore size of 100 µm showed significantly greater bone ingrowth than the other groups. This study suggested that bone regeneration into porous titanium scaffolds is pore size-dependent, while bone ingrowth was most prominent for the group with 100 µm-sized pores after 20 weeks in vivo.


Subject(s)
Bone Substitutes/chemical synthesis , Osseointegration , Polymethyl Methacrylate/chemistry , Skull Fractures/pathology , Skull Fractures/therapy , Tissue Scaffolds , Animals , Bone Regeneration , Equipment Design , Equipment Failure Analysis , Materials Testing , Porosity , Rabbits , Skull Fractures/physiopathology , Treatment Outcome , Waxes/chemistry
14.
J Oral Maxillofac Res ; 7(4): e2, 2016.
Article in English | MEDLINE | ID: mdl-28154746

ABSTRACT

OBJECTIVES: The objective of this study is to develop a Ti fibre knit block without sintering, and to evaluate its deformability and new bone formation in vivo. MATERIAL AND METHODS: A Ti fibre with a diameter of 150 µm was knitted to fabricate a Ti mesh tube. The mesh tube was compressed in a metal mould to fabricate porous Ti fibre knit blocks with three different porosities of 88%, 69%, and 50%. The elastic modulus and deformability were evaluated using a compression test. The knit block was implanted into bone defects of a rabbit's hind limb, and new bone formation was evaluated using micro computed tomography (micro-CT) analysis and histological analysis. RESULTS: The knit blocks with 88% porosity showed excellent deformability, indicating potential appropriateness for bone defect filling. Although the porosities of the knit block were different, they indicated similar elastic modulus smaller than 1 GPa. The elastic modulus after deformation increased linearly as the applied compression stress increased. The micro-CT analysis indicated that in the block with 50% porosity new bone filled nearly all of the pore volume four weeks after implantation. In contrast, in the block with 88% porosity, new bone filled less than half of the pore volume even 12 weeks after implantation. The histological analysis also indicated new bone formation in the block. CONCLUSIONS: The titanium fibre knit block with high porosity is potentially appropriate for bone defect filling, indicating good bone ingrowth after porosity reduction with applied compression.

15.
Clin Implant Dent Relat Res ; 17 Suppl 2: e670-8, 2015 Oct.
Article in English | MEDLINE | ID: mdl-25879834

ABSTRACT

BACKGROUND: Clinically, there is a demand for mechanically stronger alloyed implants; however, not much evidence exists with regard to these materials. PURPOSE: To test the osseointegration property of TiZr1317 implants in a rabbit model. MATERIALS AND METHODS: Hydrophilic titanium-zirconium alloy (TiZr1317) implants with sand-blasted and acid-etched surface (test) and hydrophilic cpTi implants with the same treatment (control) were placed pairwise in the hind limbs (two in each tibia and one in each femur) of 36 Swedish lop-eared rabbits. After 2, 4, and 12 weeks (n = 12/time point), the bone samples were subjected to removal torque (RTQ, proximal tibia and femur) and histologic/histomorphometric (distal tibia) testings. RESULTS: The control presented significantly higher RTQ than the test at 2 weeks (55 vs 36 Ncm). No differences were observed for other time points. The test presented higher mean BIC than the control (19.25 vs 13.89 %) at 4 weeks; however, there were no statistical differences for the following time point tested in vivo.The new bone area was significantly higher for the test at 4 weeks in the marrow areas. CONCLUSION: The TiZr1317 implants presented comparable biologic outcomes to that of the cpTi implants through a 12-week evaluation period.


Subject(s)
Dental Alloys/therapeutic use , Prostheses and Implants , Titanium/therapeutic use , Zirconium/therapeutic use , Animals , Biomechanical Phenomena , Female , Femur/surgery , Male , Osseointegration , Rabbits , Tibia/surgery , Torque
16.
Clin Cosmet Investig Dent ; 7: 45-53, 2015.
Article in English | MEDLINE | ID: mdl-25792855

ABSTRACT

The purpose of the study was to evaluate histologically, whether vertical bone augmentation can be achieved using a hollow ceramic space maintaining device in a rabbit calvaria model. Furthermore, the chemistry of microporous hydroxyapatite and zirconia were tested to determine which of these two ceramics are most suitable for guided bone generation. 24 hollow domes in two different ceramic materials were placed subperiosteal on rabbit skull bone. The rabbits were sacrificed after 12 weeks and the histology results were analyzed regarding bone-to-material contact and volume of newly formed bone. The results suggest that the effect of the microporous structure of hydroxyapatite seems to facilitate for the bone cells to adhere to the material and that zirconia enhance a slightly larger volume of newly formed bone. In conclusion, the results of the current study demonstrated that ceramic space maintaining devices permits new bone formation and osteoconduction within the dome.

17.
Clin Implant Dent Relat Res ; 17(6): 1048-59, 2015 Dec.
Article in English | MEDLINE | ID: mdl-25178845

ABSTRACT

BACKGROUND: Mesoporous coatings enable incorporation of functional substances and sustainedly release them at the implant site. One bioactive substance that can be incorporated in mesoporous is magnesium, which is strongly involved in bone metabolism and in osteoblast interaction. PURPOSE: The aim of this experimental study was to evaluate the effect of incorporation of magnesium into mesoporous coatings of oral implants on early stages of osseointegration. MATERIAL AND METHODS: Titanium implants were coated with thin films of mesoporous TiO2 having pore diameters of 6 nm and were loaded with magnesium. The implant surfaces were extensively characterized by means of interferometry, atomic force microscopy, scanning electron microscopy, and energy-dispersive spectroscopy and then placed in the tibiae of 10 rabbits. After 3 weeks of healing, osseointegration was evaluated by means of removal torque testing and histology and histomorphometry. RESULTS: Histological and biomechanical analyses revealed no side effects and successful osseointegration of the implants. The biomechanical evaluation evidenced a significant effect of magnesium doping on strengthening the implant-bone interface. CONCLUSIONS: A local release of magnesium from the implant surfaces enhances implant retention at the early stage of healing (3 weeks after implantation), which is highly desirable for early loading of the implant.


Subject(s)
Bone Regeneration/physiology , Dental Implantation, Endosseous/methods , Dental Implants , Magnesium/chemistry , Osseointegration/physiology , Titanium/chemistry , Animals , Implants, Experimental , Interferometry , Materials Testing , Microscopy, Atomic Force , Microscopy, Electron, Scanning , Porosity , Rabbits , Spectrometry, X-Ray Emission , Surface Properties , Tibia
18.
Clin Implant Dent Relat Res ; 17 Suppl 1: e65-74, 2015 Jan.
Article in English | MEDLINE | ID: mdl-23910386

ABSTRACT

OBJECTIVE: To 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 METHODS: Commercially 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 1 week after placement and subjected to quantitative polymerase chain reaction analysis to explore the inflammatory markers. After 8 weeks, 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. RESULTS: No statistically significant differences in immunological response to the different implant surfaces were found for IL-6 (p = .438), TGF-ß2 (p = .467), MMP-8 (p = .758), CCL-3 (p = .758), IL-8 (p = .771), and IL-1ß (0.771). Histomorphometric evaluation presented no statistically significant difference between the two mini-implant surfaces with regards to number of inflammatory cells (p = .669). CONCLUSION: Nano-hydroxyapatite-coated surfaces in the transmucosal region yielded similar inflammatory response and is suggested to be as biocompatible as commercially pure titanium surfaces.


Subject(s)
Dental Implantation, Endosseous/methods , Dental Implants , Durapatite/immunology , Gingival Crevicular Fluid/immunology , Aged , Biocompatible Materials , Biopsy , Coated Materials, Biocompatible , Female , Gene Expression , Humans , Jaw, Edentulous, Partially/rehabilitation , Male , Middle Aged , Polymerase Chain Reaction , Surface Properties , Titanium/immunology , Treatment Outcome
19.
J Oral Maxillofac Res ; 5(3): e3, 2014 Jul.
Article in English | MEDLINE | ID: mdl-25386230

ABSTRACT

OBJECTIVES: This study aims to evaluate bone response to an implant surface modified by 1α,25-dihydroxyvitamin D3 [1.25-(OH)2D3] in vivo and the potential link between 1.25-(OH) 2D3 surface concentration and bone response. MATERIAL AND METHODS: Twenty-eight implants were divided into 4 groups (1 uncoated control, 3 groups coated with 1.25-(OH)2D3 in concentrations of 10(-8), 10(-7) and 10(-6) M respectively), placed in the rabbit tibia for 6 weeks. Topographical analyses were carried out on coated and uncoated discs using interferometer and atomic-force-microscope (AFM). Twenty-eight implants were histologically observed (bone-to-implant-contact [BIC] and new-bone-area [NBA]). RESULTS: The results showed that the 1.25-(OH)2D3 coated implants presented a tendency to osseointegrate better than the non-coated surfaces, the differences were not significant (P > 0.05). CONCLUSIONS: The effect of 1.25-(OH)2D3 coating to implants suggested possible dose dependent effects, however no statistical differences could be found. It is thought that the base substrate topography (turned) could not sustain sufficient amount of 1.25-(OH)2D3 enough to present significant biologic responses. Thus, development a base substrate that can sustain 1.25-(OH)2D3 for a long period is necessary in future studies.

20.
Acta Biomater ; 10(12): 5193-5201, 2014 Dec.
Article in English | MEDLINE | ID: mdl-25153781

ABSTRACT

Local release of Mg ions from titanium implant surfaces has been shown to enhance implant retention and integration. To clarify the biological events that lead to this positive outcome, threaded implants coated with mesoporous TiO2 thin films were loaded with Mg-ions and placed in the tibia of rabbits for 3weeks, after surface characterization. Non-loaded mesoporous coated implants were used as controls. Peri-implant gene expression of a set of osteogenic and inflammatory assays was quantified by means of real-time quantitative polymerase chain reaction. The expression of three osteogenic markers (OC, RUNX-2 and IGF-1) was significantly more pronounced in the test specimens, suggesting that the release of Mg ions directly at the implant sites may stimulate an osteogenic environment. Furthermore, bone healing around implants was evaluated on histological slides and by diffraction-enhanced imaging (DEI), using synchrotron radiation. The histological analysis demonstrated new bone formation around all implants, without negative responses, with a significant increase in the number of threads filled with new bone for test surfaces. DEI analysis attested the high mineral content of the newly formed bone. Improved surface osteoconductivity and increased expression of genes involved in the bone regeneration were found for magnesium-incorporation of mesoporous TiO2 coatings.


Subject(s)
Bone Regeneration/physiology , Bone Screws , Intercellular Signaling Peptides and Proteins/metabolism , Magnesium/administration & dosage , Magnesium/chemistry , Osteogenesis/physiology , Titanium/chemistry , Animals , Biocompatible Materials/chemistry , Biocompatible Materials/pharmacology , Bone Regeneration/drug effects , Coated Materials, Biocompatible/chemistry , Coated Materials, Biocompatible/pharmacology , Diffusion , Equipment Failure Analysis , Osteogenesis/drug effects , Porosity , Prosthesis Design , Rabbits
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