Contemporary Results of Carotid Artery Stenting Using Low-Profile Dual-Metal Layer Nitinol Micromesh Stents in Relation to Single-Layer Carotid Stents.

PURPOSE: To evaluate patients characteristics, procedural details, perioperative outcomes, and midterm results of carotid artery stenting (CAS) performed with the Roadsaver/Casper stent (Terumo Corp, Tokyo, Japan) as compared to concurrent patients treated with other commercially available carotid stents. MATERIALS AND METHODS: This is a single-center, retrospective, nonrandomized study including 200 consecutive patients who underwent a total of 205 elective CAS procedures due to severe internal carotid artery stenosis between April 2015 and December 2018. Procedural data and outcomes for patients treated with the Roadsaver/Casper stent implantation (100 procedures, in 97 patients) vs first-generation carotid stents implantations (90 procedures, in 88 patients) were compared. Fifteen patients were treated with CGuard carotid stent (InspireMD, Tel Aviv, Israel), and outcomes were reported separately. Primary endpoints were the occurrence of major adverse cerebrovascular events (MACE), including death, ipsilateral stroke, and transitory ischemic attack (TIA). Secondary endpoints were the rate of intrastent stenosis, the need for reintervention, and the occurrence of adverse cardiovascular events, including myocardial infarction, arrhythmias, and need for inotropic support. RESULTS: No difference in demographics and preoperative risk factors were observed between patients treated with and without the Roadsaver/Casper stent. The mean procedure time was shorter in the Roadsaver/Casper group (40.7±16.9 vs 49.4±27.3 minutes; p=0.008), while radial percutaneous access was more frequent (24% vs 5%; p<0.001). The rate of stroke/TIA/death at 30 days was 3% in the Roadsaver group vs 1% in the first-generation stent group (p=0.623). The primary patencyrate was 100% and 93.4% at 1- and 3-year of follow-up in the Roadsaver/Casper groupand 99% and 94.3% in the other stent group, respectively (p=0.95). CONCLUSIONS: In this real-world cohort of patients undergoing CAS, the Roadsaver/Casper stent was used to treat more symptomatic and vulnerable carotid plaques as compared to other carotid stents. Nevertheless, patients treated with this low-profile dual-layer micromesh stent showed low events rates at both 30 days and follow-up, similar to that observed for other stents.

Elective Embolization of Splenic Artery Aneurysms with an Ethylene Vinyl Alcohol Copolymer Agent (Squid) and Detachable Coils.

PURPOSE: To report the safety and efficacy of the embolization of splenic artery aneurysms (SAAs) with coils plus ethylene vinyl alcohol copolymer (EVOH) agent. MATERIALS AND METHODS: A single-center retrospective study was conducted from 2016 to 2019 to collect SAAs. Twelve asymptomatic patients (mean age, 59 years) with 15 SAAs (mean size, 23.6 mm; size range, 15-40 mm) were treated with embolization. Embolization was performed with EVOH (Squid 8/34) and fibered detachable coils. Transfemoral embolization was performed with a microcatheter to achieve a splenic artery occlusion embolizing the SAA and its efferent and afferent branches. Follow-up was based on color Doppler ultrasound at 24 hours and on computed tomography (CT) angiography at 1 (n = 12) and 6 months (n = 12) after embolization. Mean number of coils and Squid vials used for each patient, major/minor complications, technical success, 30-day clinical success, cases of revascularization/reintervention, and mortality were assessed. Technical success was defined as complete exclusion of the aneurysmal segment and cessation of blood flow into the sac. Clinical success at 1 month was based on the absence of clinical symptoms and the exclusion of aneurysm revascularization on CT angiography. RESULTS: The mean number of coils and Squid vials was 5.75 (standard deviation [SD], 1.58; range, 3-9) and 1.41 (SD, 0.49; range, 1-2), respectively. Both technical and 30-day clinical success were 100%, with no cases of aneurysm revascularization (CT angiography performed in all patients at 1 month and 6 months and in 3 patients at 24 months). No major complications or fatal events were recorded. In terms of minor complications, 2 cases of mild pancreatitis (transient amylases increase) and 1 case of focal splenic ischemia without clinical sequelae were recorded. CONCLUSIONS: Embolization in SAAs using coils plus EVOH was safe and effective without SAA revascularization.

Fracture of a Supera Interwoven Nitinol Stent After Treatment of Popliteal Artery Stenosis.

PURPOSE: To present a Supera stent fracture following treatment of popliteal artery stenosis. CASE REPORT: A 60-year-old man previously treated with angioplasty/stenting of a popliteal artery lesion with a Supera stent presented at 8 months with in-stent occlusion that proved to be secondary to stent fracture. CONCLUSION: Supera interwoven nitinol stents, despite having higher radial force and conformability than classic tube stents, are not free from fracture. Moreover, due to their peculiar structure, a break in these stents results in complete loss of integrity and consequent device collapse, thus jeopardizing endovascular recanalization and relining.

Functionalized magnesium alloys obtained by superplastic forming process retain osteoinductive and antibacterial properties: An in-vitro study.

OBJECTIVES: This study aimed to investigate the biocompatibility, osteogenic and antibacterial activity of biomedical devices based on Magnesium (Mg) Alloys manufactured by Superplastic Forming process (SPF) and subjected to Hydrothermal (HT) and Sol-Gel Treatment (Sol-Gel). METHODS: Mg-SPF devices subjected to Hydrothermal (Mg-SPF+HT) and Sol-Gel Treatment (Mg-SPF+Sol-Gel) were investigated. The biocompatibility of Mg-SPF+Sol-Gel and Mg-SPF+HT devices was observed by indirect and direct cytotoxicity assays, whereas the colonization of sample surfaces was assessed by confocal microscopy. qRT-PCR analysis and microbial growth curve analyses were employed to evaluate the osteogenic and antibacterial activity of both SPF-Mg treated devices, respectively. RESULTS: Mg-SPF+HT and Mg-SPF+Sol-Gel showed a high degree of biocompatibility. Analysis of mRNA expression of osteogenic genes in cells cultured on Mg-treated devices revealed a significant upregulation of the expression levels of BMP2 and Runx-2. Furthermore, the bacterial growth in strains developed in contact with both the Mg-SPF+HT and Mg-SPF+Sol-Gel devices was lower than that observed in the control. SIGNIFICANCE: Hydrothermal and Sol-Gel Treatments of Mg alloys obtained through the SPF process demonstrated bioactive, osteogenic and antibacterial activity, offering a promising alternative to conventional Mg-based devices. The obtained Mg-based materials may have the potential to enhance the tunability of temporary devices in maxillary reconstruction, eliminating the need for second surgeries, and ensuring a good bone reconstruction and a reduced implant failure rate due to bacterial infections.

Gallium-doped zirconia coatings modulate microbiological outcomes in dental implant surfaces.

Despite the significant recent advances in manufacturing materials supporting advanced dental therapies, peri-implantitis still represents a severe complication in dental implantology. Herein, a sol-gel process is proposed to easily deposit antibacterial zirconia coatings onto bulk zirconia, material, which is becoming very popular for the manufacturing of abutments. The coatings' physicochemical properties were analyzed through x-ray diffraction and scanning electron microscopy-energy-dispersive x-ray spectroscopy investigations, while their stability and wettability were assessed by microscratch testing and static contact angle measurements. Uniform gallium-doped tetragonal zirconia coatings were obtained, featuring optimal mechanical stability and a hydrophilic behavior. The biological investigations pointed out that gallium-doped zirconia coatings: (i) displayed full cytocompatibility toward human gingival fibroblasts; (ii) exhibited significant antimicrobial activity against the Aggregatibacter actinomycetemcomitans pathogen; (iii) were able to preserve the commensal Streptococcus salivarius. Furthermore, the proteomic analyses revealed that the presence of Ga did not impair the normal oral microbiota. Still, interestingly, it decreased by 17% the presence of Fusobacterium nucleatum, a gram-negative, strictly anaerobic bacteria that is naturally present in the gastrointestinal tract. Therefore, this work can provide a valuable starting point for the development of coatings aimed at easily improving zirconia dental implants' performance.

Silver acetate and Triclosan Antimicrobial Graft Evaluation for surgical Repair of aortic disease (STAGER Study).

BACKGROUND: The aim of this study was to assess perioperative and late performance of a silver acetate and triclosan impregnated antimicrobial vascular graft (Intergard Synergy, Intervascular SAS, La Ciotat, France) during open surgical repair of abdominal aortic aneurysms (AAA), and to compare it with standard polyester grafts ones. METHODS: This retrospective single-centre study (STAGER Study, clinicaltrials.gov: NCT04557254) included patients undergone non-infectious AAA surgical repair between 2012 and 2019, divided into two groups according to the implanted aortic prosthesis: standard polyester graft (PolyG) and silver-triclosan graft (SynG). Early primary endpoints were 30-day mortality, major adverse events (MAEs), and reintervention rates; late primary endpoints were overall and aortic-related survival, reintervention-free survival, and graft infection rate at a mean follow-up (FU) of 49.4±26.8 months. RESULTS: Five hundred forty-seven patients were included [PolyG 49%, and SynG 51%]. Both groups were substantially homogeneous in risk factors and demographics. Two patients died within 30 days. In-hospital MAE rate [PolyG 14.2% vs. SynG 10.7%; P=.248] and 30-day reintervention rate were not significantly different [PolyG 2.6% vs. SynG 1.4%; P=.374]. At 5 years, overall survival in the PolyG and SynG groups were 85% and 84%, respectively. Reintervention-free survival was 82% for both groups. Aortic-related survival was 95% and 96%, respectively. Graft infection was observed in 8 (3.3%) PolyG patients and 5 (1.8%) SynG patients. CONCLUSIONS: Silver acetate and triclosan impregnated grafts demonstrated good early and mid-term results, being considered safe and durable for AAA open repair. Similar graft infection and related death rates were observed compared to polyester standard grafts, supporting non-superiority of one graft over the other.

TEVAR for ruptured mycotic aneurysm in a patient with a left ventricular assist device.

PURPOSE: To report endovascular treatment of a ruptured mycotic aneurysm in a patient with previous cardiac surgery, a cardioverter-defibrillator, and an intrathoracic left ventricular assist device (LVAD). CASE REPORT: A 75-year-old man was admitted for a syncopal episode and severe back pain. The patient had a past history of postischemic dilatative cardiomyopathy for which a cardioverter-defibrillator was implanted. An LVAD and bioprosthetic aortic valve were subsequently placed due to severe cardiogenic shock. The postoperative course was complicated by methicillin-resistant Staphylococcus aureus mediastinitis and acute renal failure requiring temporary dialysis. At the current admission 4 months later, urgent computed tomography (CT) showed a ruptured aneurysm in the middle third of the descending thoracic aorta; blood cultures were positive for Candida sp . The patient was hemodynamically stable, so he was placed in intensive care and given targeted antimicrobial therapy while an endovascular treatment was planned. At surgery, a rifampicin-soaked Relay Plus 30-mm×95-cm stent-graft was deployed through a right common femoral cutdown to seal the aortic rupture. Successful aneurysm exclusion was confirmed by intraoperative transesophageal echocardiography (TEE). At the 6-month follow-up, the patient was without recurrent pathology or graft infection as demonstrated by CT. CONCLUSION: Thoracic endovascular aortic repair in patients with LVAD is peculiar for several aspects: accurate planning is necessary to adequately visualize the aortic lesion despite the presence of many radiopaque devices and the femoral arteries are pulseless. Moreover, extremely slow washout of contrast from the aortic rupture prevents correct assessment of final sac exclusion with angiography; intraoperative TEE monitoring proved extremely useful.

Final operative and midterm results of the European experience in the RELAY Endovascular Registry for Thoracic Disease (RESTORE) study.

PURPOSE: Thoracic endovascular aortic repair is increasingly becoming the standard treatment of many thoracic aortic pathologies. New reliable and accurate stent grafts are emerging to widen the endovascular treatment options. We report the results of RELAY (Bolton Medical, Barcelona, Spain) in the large RELAY Endovascular Registry for Thoracic Disease (RESTORE) European registry. METHODS: RESTORE is a multicenter, prospective European registry involving 22 centers in seven European countries. The RELAY device is composed of a stent graft (self-expanding nitinol stents and a polyester vascular graft) and a delivery device specifically designed for the thoracic aorta. Included were acute and elective patients presenting with a variety of pathologies (aneurysms, dissections, ulcerations, intramural hematomas, pseudoaneurysms) and lesions in different aortic and anatomic locations (ascending, arch, descending and thoracoabdominal). RESULTS: The registry enrolled 304 patients from April 2005 to January 2009. All-cause mortality at 30 days was 7.2%. Freedom from all cause mortality and freedom from device- and procedure-related mortality at 2 years were 78.5% and 95.9%, respectively. An average of 1.26 graft components were used per patient, with a technical success of 97.7% irrespective of the etiology. Early endoleak rate was 4.6%. Perioperatively, stroke and paraplegia were registered in 1.6% and 2.0%, respectively. CONCLUSIONS: The results of RESTORE support the safety of thoracic endovascular aortic repair with the RELAY stent graft, even in acute and complicated situations. The device was highly efficient in angulated aortic anatomies, with acceptable mortality and a low rate of neurologic complications.

The ceramic-on-metal coupling in total hip replacements for young patients: a review study.

In the last two decades the performance of total hip replacements (THR) has constantly improved, thanks largely to advances in the field of material science and technology. Although contemporary devices are clinically very reliable, some problems still need to be addressed: the wear of ultra high molecular weight polyethylene components, the release of metal ions from metal-on-metal joints, the toughness of the ceramic cups and the possibility of squeaking for ceramic-on-ceramic couplings. All these drawbacks become particularly relevant in case of THR for young and active patients, when the life expectancy of the orthopedic device is very high and the possibility of mechanical shocks is not negligible.In the last few years an innovative ceramic-on-metal tribologic coupling has been introduced in clinical use. This novel configuration represents a very promising solution to all the aforementioned issues. Ceramic-on-metal offers both the strength points of ceramic and metal surfaces, and overcomes the limits of metal-on-metal and ceramic-on-ceramic bearings. For this reason, the ceramic-on-metal coupling has become the object of investigation for several laboratory studies and has been tested in clinical trials. This review study compares the scientific outcomes of the research on ceramic-on-metal bearings, confirming that this innovative articulation has the potential to be a suitable and attractive solution for young and active patients.

Early results of mechanochemical ablation for small saphenous vein incompetency using 2% polidocanol.

OBJECTIVE: The aim of the present study was to investigate the early results of mechanochemical ablation (MOCA) for the treatment of small saphenous vein (SSV) incompetence. METHODS: We performed a single-center, retrospective analysis of a prospectively collected database of 60 patients treated with MOCA for single-axis SSV incompetence. All procedures were performed with the patient under local anesthesia using the ClariVein catheter (Merit Medical, South Jordan, Utah) combined with 2% polidocanol and, where appropriate, additional microphlebectomy. The primary study endpoint was to assess the SSV occlusion rate at the 1-, 6-, and 12-month follow-up examinations. The secondary endpoints included the Venous Clinical Severity Score, quality of life (QoL) assessment, periprocedural pain, and further complications after the intervention and during the follow-up period. Patient QoL was assessed using the Aberdeen Varicose Vein Questionnaire. Pain was measured using a 100-mm visual analog scale. RESULTS: Technical success was achieved in 100% of the cases. The mean visual analog scale score on the first postoperative day was 15 mm. No major events were recorded. No neurological complications or deep vein thrombosis were observed. Minor complications included ecchymosis in 3.3% of cases (2 of 60), transient phlebitis of the SSV in 5% of cases (3 of 60), and itching in 3.3% of cases (2 of 60). At the 1-, 6-, and 12-month follow-up examinations, the occlusion rate was 100% (60 of 60), 98.3% (57 of 58), and 92.6% (50 of 54). The median Venous Clinical Severity Score had significantly decreased from 5 (interquartile range [IQR], 3-6) at baseline to 2 (IQR, 1-4) at the 1-month follow-up (P < .001), 1 (IQR, 1-2) at the 6-month follow-up (P < .001) and 1 (IQR, 0-1) at the 12-month follow-up (P < .001). The mean Aberdeen Varicose Vein Questionnaire score had improved from the baseline score of 25 ± 14.61 to 15.81 ± 13.76 at the 1-month follow-up (P < .001), to 9.81 ± 7.42 at the 6-month follow-up (P < .001) and 4.73 ± 3.32 at the 12-month follow-up (P < .001). CONCLUSIONS: The results of our study have shown that MOCA is a feasible, safe, and painless procedure for the treatment of SSV incompetence with an occlusion rate of 92.6% at the 12-month examination. No sural nerve injuries or other major complications were observed. The procedure also provided good clinical results and positive effects on patient QoL.

Mesoporous zirconia surfaces with anti-biofilm properties for dental implants.

Cytocompatible bioactive surface treatments conferring antibacterial properties to osseointegrated dental implants are highly requested to prevent bacteria-related peri-implantitis. Here we focus on a newly designed family of mesoporous coatings based on zirconia (ZrO2) microstructure doped with gallium (Ga), exploiting its antibacterial and pro-osseo-integrative properties. The ZrO2films were obtained via sol-gel synthesis route using Pluronic F127 as templating agent, while Ga doping was gained by introducing gallium nitrate hydrate. Chemical characterization by means of x-ray photoelectron spectroscopy and glow discharge optical emission spectroscopy confirmed the effective incorporation of Ga. Then, coatings morphological and structural analysis were carried out by transmission electron microscopy and selected area electron diffraction unveiling an effective stabilization of both the mesoporous structure and the tetragonal ZrO2phase. Specimens' cytocompatibility was confirmed towards gingival fibroblast and osteoblasts progenitors cultivated directly onto the coatings showing comparable metabolic activity and morphology in respect to controls cultivated on polystyrene. The presence of Ga significantly reduced the metabolic activity of the adhered oral pathogensPorphyromonas gingivalisandAggregatibacter actinomycetemcomitansin comparison to untreated bulk zirconia (p< 0.05); on the opposite, Ga ions did not significantly reduce the metabolism of the oral commensalStreptococcus salivarius(p> 0.05) thus suggesting for a selective anti-pathogens activity. Finally, the coatings' ability to preserve cells from bacterial infection was proved in a co-culture method where cells and bacteria were cultivated in the same environment: the presence of Ga determined a significant reduction of the bacteria viability while allowing at the same time for cells proliferation. In conclusion, the here developed coatings not only demonstrated to satisfy the requested antibacterial and cytocompatibility properties, but also being promising candidates for the improvement of implantable devices in the field of implant dentistry.

Graft perforation by a dislocated rib fracture after open thoracoabdominal aortic repair: emergent endovascular and open repair.

PURPOSE: To describe perforation of a Dacron aortic graft due to a post-thoracotomy dislocated rib fracture in a young Marfan patient. CASE REPORT: Six months after a successful open repair of a type II dissecting thoracoabdominal aortic aneurysm (TAAA), a 40-year-old woman with Marfan syndrome underwent elective repair of a post-thoracotomy dislocated rib fracture. During the procedure, the graft ruptured; 2 TAG stent-grafts were emergently implanted to reline the existing aortic graft. The fractured rib was then resected. The postoperative course was uneventful, without residual leak at computed tomography at 3 days. At 18 months, the patient is well, without need of further operations. CONCLUSION: Early correction of any dislocated rib fracture close to a thoracic aortic graft should be considered, especially if the graft is not wrapped by the aneurysm sac. In these patients, in-graft endovascular relining associated with repair of the rib fracture may be a feasible and effective alternative to redo thoracotomy and surgical graft repair. Prior to attempting rib resection, appropriate thoracic endografts should be on hand in case an endovascular bailout is needed.

Retrograde type A dissection after endovascular repair of a "zone 0" nondissecting aortic arch aneurysm.

Retrograde type A dissection (RTAD) is not so uncommon after thoracic endovascular aortic repair of type B dissections, especially in the presence of connective tissue disorders. Risk of RTAD after thoracic endovascular aortic repair of nondissecting aneurysms has still to be clarified, mainly if proximal arch involvement requires hybrid repair with ascending aortic side clamping, supra-aortic trunks proximal re-routing and endograft landing in ascending aorta. We report a mid-term RTAD after hybrid repair of a proximal arch nondissecting aneurysm without connective tissue disorders. The technique for ascending aortic replacement without arch endograft removal and literature review about this poorly known complication are presented.

Aortobifemoral bypass grafting using expanded polytetrafluoroethylene stretch grafts in patients with occlusive atherosclerotic disease.

The aim of this retrospective study was to evaluate the performance of bifurcated, longitudinally extensible (stretch), expanded polytetrafluoroethylene (ePTFE) grafts implanted in patients with aortoiliac or aortofemoral occlusive atherosclerotic disease. Between October 1991 and December 2005, 822 consecutive patients (708 men, 114 women; mean age 63.8 years) underwent aortoiliac or aortofemoral reconstruction using a bifurcated ePTFE stretch graft. Preoperatively, all patients had ultrasonographic and arteriographic evaluations and were divided into groups according to the TASC II morphological stratification of iliac lesions. Seventy-seven patients (9.4%) had type B lesions, 314 (38.2%) had type C lesions, and 431 (52.4%) were classified as type D lesions. Endarterectomy of the aorta was required in 172 patients (21%); femoral arteries were endarterectomized in 222 (27%). Femoropopliteal bypass grafting was performed in 18 patients, aortorenal bypass in 12, and mesenteric artery grafting in one. One patient died perioperatively of a myocardial infarction. Perioperative morbidity included cardiac (2.2% of patients), respiratory (0.9%), and gastrointestinal (1.2%) complications, as well as acute renal insufficiency (1.3%). Seven patients had bleeding requiring surgical revision within the first 24hr after surgery. There were four cases (0.5%) of immediate graft thrombosis and five (0.6%) of single-limb graft thrombosis. During a mean follow-up time of 72 months (range 28-170), 58 patients (7.1%) were lost to follow-up and 205 patients (24.9%) died. The primary and secondary graft-patency rates during the observation period were 90.6% and 97.9%, respectively. Twelve late graft occlusions resolved after thrombectomy alone. Eleven cases of single-limb late thrombosis resolved after thrombectomy and profundoplasty. The limb-salvage rate during the observation period in patients who underwent operation for critical limb ischemia was 84.5%. There were nine postoperative graft infections (1.1% infection rate) in the series. Our long-term experience with ePTFE stretch grafts in aortoiliac and aortofemoral reconstruction shows that these prostheses have a high rate of patency and a low rate of graft-related complications.

Osteogenic differentiation of human mesenchymal stromal cells on surface-modified titanium alloys for orthopedic and dental implants.

PURPOSE: Surface properties of titanium alloys, used for orthopedic and dental applications, are known to affect implant interactions with host tissues. Osteointegration, bone growth and remodeling in the area surrounding the implants can be implemented by specific biomimetic treatments; these allow the preparation of micro/nanostructured titanium surfaces with a thickened oxide layer, doped with calcium and phosphorus ions. We have challenged these experimental titanium alloys with primary human bone marrow stromal cells to compare the osteogenic differentiation outcomes of the cells once they are seeded onto the modified surfaces, thus simulating a prosthetic device-biological interface of clinical relevance. METHODS: A specific anodic spark discharge was the biomimetic treatment of choice, providing experimental titanium disks treated with different alkali etching approaches. The disks, checked by electron microscopy and spectroscopy, were subsequently used as substrates for the proliferation and osteogenic differentiation of human cells. Expression of markers of the osteogenic lineage was assessed by means of qualitative and quantitative PCR, by cytochemistry, immunohistochemistry, Western blot and matrix metalloprotease activity analyses. RESULTS: Metal surfaces were initially less permissive for cell growth. Untreated control substrates were less efficient in sustaining mineralized matrix deposition upon osteogenic induction of the cells. Interestingly, bone sialo protein and matrix metalloprotease 2 levels were enhanced on experimental metals compared to control surfaces, particularly for titanium oxide coatings etched with KOH. DISCUSSION: As a whole, the KOH-modification of titanium surfaces seems to allow the best osteogenic differentiation of human mesenchymal stromal cells, representing a possible plus for future clinical prosthetic applications.

Laser versus LED polymerization: Comparison of in vitro preventive sealing procedures.

INTRODUCTION:: The technique of sealing is a widely accepted procedure for prevention of caries. The aim of our in vitro study was to compare the effect of two different curing units (traditional LED source and innovative laser diode lamp) on the integrity of fissure sealant material and its interface with tooth enamel. MATERIALS AND METHODS:: Sixty healthy third molars were randomly assigned to two groups. In group A were teeth intended for polymerization by LED B lamp, and group B comprised teeth to be polymerized by an innovative laser diode. Both groups were treated with the traditional sealing technique, subjected to a metallization process, and analyzed by scanning electron microscope. RESULTS:: Micro-gaps between the sealant and the enamel were found in specimens in both A (43%) and B (40%) groups ( p=0.793), and sealant shrinkage was seen. Significant differences between the groups emerged in the percentage of perimetric micro-erosion sites (80% vs. 100%, p=0.010) and the presence of holes and micro-bubbles on the sealant surface (21% vs. 63%, p=0.001). CONCLUSIONS:: Although macroscopic clinical polymerization occurred with both instruments, the microscopic evaluation showed significant differences between the studied groups in terms of perimetric micro-erosion sites and micro-bubbles, which were higher in laser-cured samples.

Effect of a multiphasic anodic spark deposition coating on the improvement of implant osseointegration in the osteopenic trabecular bone of sheep.

PURPOSE: Anodic spark deposition techniques have been effectively applied to achieve a microporous morphology on metals. To investigate the effect of a new anodic spark deposition-based treatment in the enhancement of titanium implant osseointegration in trabecular bone of aged and ovariectomized sheep, a histomorphometric and microhardness study was carried out. MATERIALS AND METHODS: Ten sheep were divided into 2 groups. Five were submitted to a bilateral ovariectomy to induce an estrogen-deficiency osteopenia (Ovariectomized), and 5 were left untreated (Aged). Twenty-four months later, they underwent a bilateral implantation of commercially pure titanium screw threads in the lateral surface of femoral condyles: electrochemically treated titanium (SP) and acid-etching treated titanium (BioRough). Twelve weeks after the second operation, the animals were sacrificed and femur segments and iliac crest biopsy specimens were examined for histomorphometric and microhardness evaluations. RESULTS: The histomorphometry of the trabecular bone of the iliac crest biopsy specimens and that around screws showed marked signs of bone rarefaction in the Ovariectomized group when compared to the Baseline and Aged groups. Significantly greater bone-implant contact was observed for SP implants in comparison with BioRough implants in both the Aged (P < .001) and Ovariectomized (P < .01) groups. No significant differences in terms of microhardness were found between SP and BioRough implants within the Aged group, while a significantly higher Bone Maturation Index was observed for SP in the Ovariectomized group (P < .05). CONCLUSIONS: The novel electrochemical treatment SP produced the most promising results and was able to introduce substantial improvements in achieving the fast and stable osseointegration of implants in osteopenic bone.

Electrochemical surface modification of titanium for implant abutments can affect oral bacteria contamination.

PURPOSE: This research concerns the characterization of an electrochemical surface treatment applied to titanium, focused especially on the treatment of the transmucosal area of dental implants and abutments. The treatment is applied to improve soft tissue adhesion, to control and limit bacteria adhesion and proliferation, and to improve the aesthetic performance through a proper colorization of the metal surface. METHODS: The electrochemical treatment considered, obtained on titanium by Anodic Spark Deposition technique (ASD), was performed in a calcium phosphate enriched solution. The bacteria behaviour was assessed by in vitro and in vivo tests. RESULTS: The investigated ASD treatment showed some antibacterial effect. No negative cytocompatibility effects were found on MG63 - human osteosarcoma cell lines and L929 - murine fibroblasts. CONCLUSIONS: The ASD modified treatment was found capable of modifying the titanium oxide layer providing a prevalent anatase crystalline structure and a microporous morphology, which can play an important role in the tissue integration process. The treatment was found capable of enriching the surface with calcium, providing improved biocompatibility and a light gray colorization. This last point is important for the aesthetic improvement of dental implant systems in the transgingival area.

Comparative in vitro study on a ultra-high roughness and dense titanium coating.

A new implant surface has been developed with the purpose of avoiding as much stress shielding as possible, and thus prolong the prosthesis lifespan. The aim of this study was to investigate the in vitro effect of this new ultra-high roughness and dense Titanium (Ti) surface (PG60, Ra = 74 microm) in comparison with medium (TI01, Ra = 18 microm) and high (TI60, Ra = 40 microm) roughness and open porous coatings; all the coatings were obtained by vacuum plasma spraying. MG63 osteoblast-like cells were seeded on the tested materials and polystyrene, as control, for 3 and 7 days. Cells proliferated on the material surfaces similarly to the control. Alkaline phosphatase activity had lower values for TI60 than TI01 (p < 0.0005) and PG60 (p < 0.005). Osteocalcin levels measured on TI60 were significantly (p < 0.0005) lower in comparison with TI01 and PG60 at 7 days. Procollagen-I synthesis reduced with increasing roughness and the lowest data was found for PG60. While at 3 days Transforming Growth Factor beta1 levels augmented with increasing roughness, at 7 days TI60, the high roughness surface, was significantly lower than PG60 (p < 0.005) and TI01 (p < 0.001). All tested materials showed significantly higher Interleukin-6 levels than those of polystyrene at both experimental times. Nitric Oxide activity on TI01 was significantly (p < 0.05) higher than on TI60 and polystyrene. In conclusion, the new ultra-high roughness and dense coating PG60 provided a good biological response, even though, at least in vitro, it behaved similarly to the coatings already used in orthopaedics.

In vitro assessment of the osteointegrative potential of a novel multiphase anodic spark deposition coating for orthopaedic and dental implants.

Hydroxyapatite coatings have been proven to improve the osteointegration of metal implants through a tight binding to the bone mineral phase as well as through favorable osteoblast adhesion and proliferation onto the implant surface. However, hydroxyapatite coatings are not stable and they tend to delaminate from the metal surface when challenged by the mechanical stresses experienced by the implant. Recently, a new multiphase anodic spark deposition (ASD) method has been optimized where the formation of a thick oxide film is followed by the deposition of a calcium phosphate mineral phase and its etching by alkali. The data in this paper demonstrate that this novel type of coating, BioSpark, improves the material osteointegration potential when compared to conventional ASD while offering more mechanical stability. A faster mineralization was obtained by incubation in simulated body fluids and osteoblasts showed better adhesion, proliferation, differentiation, and collagen production. These performances were related to the surface morphology, to the film calcium/phosphate ratio and its surface oxygen content, as well as to a preferential binding of structural proteins such as fibronectin.