Standardized fractal bench test evaluation of coronary stents: Performances in bifurcation lesions treated by the re-proximal optimization technique.

BACKGROUND: Bifurcation lesions in coronary arteries are complex to treat with coronary stents, which are not designed for that purpose and can be unproperly deployed. Moreover, devices are constantly evolving, and so are angioplasty techniques. OBJECTIVES: The aim of this study was to determine the performances of different stents in the treatment of bifurcation lesions using the re-proximal optimization technique (rePOT). METHODS: Eleven stent platforms were evaluated: Xience Sierra (Abbott), Xience Alpine (Abbott), Synergy (Boston), Coroflex Isar (Bbraun), Cobra PzF (Celonova), Ultimaster (Terumo), Resolute Integrity (Medtronic), Resolute Onyx (Medtronic), Optimax (Hexacath), Orsiro (Biotronik), and Absorb (Abbott). Stents were deployed in a silicone fractal bifurcation model using the rePOT. Micro-computed tomography was performed to assess side branch ostium coverage and strut malapposition, as well as the effect of rePOT on stent cell area. RESULTS: Our study showed significant differences between stent platforms regarding side branch ostium coverage (p = .002). The Synergy and Cobra PzF stents were the most performant devices to avoid ostium coverage. Strut malapposition varied significantly between devices (p = .008) but the percentage of malapposed struts was relatively low. Significant differences were observed between stents regarding the cell area before (p = .002) and also after rePOT (p = .003), and the increase in cell area caused by rePOT varied considerably between devices (p = .08). CONCLUSION: This study highlighted significant differences in the performances of stent platforms deployed in a fractal bifurcation model using rePOT, with a variable impact of the procedure on stent cell area.

Standardized bench test evaluation of coronary stents: Biomechanical characteristics.

OBJECTIVES: The purpose of the study was to develop a standardized and global bench test protocol to evaluate the biomechanical characteristics of the most currently used drug-eluting coronary stents. BACKGROUND: The use of coronary stents has contributed to the reduction of cardiovascular mortality but can be associated with specific complications. Improving the biomechanical matching between the stents and the coronary anatomy may reduce these complications. METHODS: We assessed five commercially available drug-eluting stents: the Absorb, Orsiro, Resolute Onyx, Synergy, and Xience Alpine stents. Following stent deployment at nominal pressure in ambient air, radial elastic recoil and foreshortening were measured. Flexibility (crimped and deployed stents) and longitudinal and radial resistances were evaluated using a mechanical tester. RESULTS: Biomechanical characteristics were significantly different for all tested devices (ANOVA, P < 0.01). The Synergy, Orsiro, and Xience Alpine stents presented the lowest elastic recoil. The Synergy and Resolute Onyx stents were the most flexible devices. The Xience Alpine and Absorb stents had the highest longitudinal and radial resistances. CONCLUSIONS: Drug-eluting coronary stents used in current clinical practice have very different biomechanical characteristics, which should be taken into consideration to select the most appropriate device for each clinical situation.

Periimplantitis and Implant Body Roughness: A Systematic Review of Literature.

PURPOSE: The aim of this systematic review was to evaluate whether implant roughness is associated with periimplantitis in humans. MATERIALS AND METHODS: An electronic search of 3 databases (MEDLINE, Web of Knowledge, and the Cochrane Library) was undertaken until October 2017 and was supplemented by manual searching. Prospective studies were included if they met the following criteria: (1) give a clear definition of periimplantitis and (2) contain outcome data (clinical and radiological data) considering the periimplantitis rate. A systematic review was carried out to evaluate the impact of roughness on the periimplantitis rate. RESULTS: Of 4690 potentially eligible articles, 22 were included in the qualitative analysis and quantitative synthesis. CONCLUSIONS: This systematic review suggests that roughness and surface treatment of dental implants are important factors associated with periimplantitis.

Monomer release from orthodontic retentions: An in vitro study.

INTRODUCTION: The adhesives used to bond orthodontic retentions are low-loaded composite resins with a resinous matrix containing bisphenol A diglycidyl ether dimethacrylate synthesized from bisphenol A (BPA), fluidizers such as triethylene glycol dimethacrylate (TEGDMA) and hydrophilic polymers such as hydroxyethylmethacrylate. BPA disrupts the endocrine balance, and TEGDMA has high risks for human health: eg, allergies and cytotoxicity. The aim of this study was to evaluate in vitro the release of monomers from orthodontic bonded retentions. METHODS: A reproducible model of bonded retentions was carried out using calibrated molds. We analyzed the release of monomers by gas phase chromatography coupled with mass spectrometry. RESULTS: This model allowed us to qualitatively and quantitatively evaluate the in-vitro release of monomers from orthodontic adhesives. The quantitative and qualitative analyses showed no BPA release above the 0.02 ppm detection limit. A greater release of TEGDMA was observed with Transbond LR (31.7 µg/mL) than with Transbond XT (13.12 µg/mL) (both, 3M Unitek, Monrovia, Calif). Other toxic components (iodobenzene, iodobiphenyl, triphenyl stibine, and so on) were also identified. CONCLUSIONS: Toxic and carcinogenic molecules not mentioned in the material safety data sheets were identified.

The oral cavity microbiota: between health, oral disease, and cancers of the aerodigestive tract.

Many studies show that the human microbiome plays a critical role in the chronic pathologies of obesity, inflammatory bowel diseases, and diabetes. More recently, the interaction between cancer and the microbiome has been highlighted. Most studies have focused on the gut microbiota because it represents the most extensive bacterial community, and the body of evidence correlating it with gut syndromes is increasing. However, in the strict sense, the gastrointestinal (GI) tract begins in the oral cavity, and special attention should be paid to the specific flora of this cavity. This study reviewed the current knowledge about the various microbial ecosystems of the upper part of the GI tract and discussed their potential link to carcinogenesis. The overall composition of the microbial communities, as well as the presence or absence of "key species", in relation to carcinogenesis is addressed. Alterations in the oral microbiota can potentially be used to predict the risk of cancer. Molecular advances and the further monitoring of the microbiota will increase our understanding of the role of the microbiota in carcinogenesis and open new perspectives for future therapeutic and prophylactic modalities.

Release of monomers from orthodontic adhesives.

INTRODUCTION: Most composite resins release both bisphenol A (BPA), which disrupts the endocrine balance, and triethylene glycol dimethacrylate (TEGDMA), which has high risks for human health: eg, allergies and cytotoxicity. The aim of this study was to characterize monomers released from orthodontic adhesives. METHODS: We studied samples of orthodontic adhesives by associating 2 techniques: gas phase chromatography and mass spectrometry. RESULTS: The in-vitro analysis detected significant quantities of BPA, TEGDMA, and other monomers in orthodontic adhesives used in daily practice: Transbond XT, Transbond Supreme LV (both, 3M Unitek, Monrovia, Calif), Blugloo (Ormco, Orange, Calif), and MonoLok 2 (Rocky Mountain Orthodontics, Denver, Colo). CONCLUSIONS: Clinicians should consider that orthodontic adhesives contain BPA, an endocrine disruptor; TEGDMA, an allergic and a cytotoxic compound; and carcinogenic genotoxic compounds. These molecules are not mentioned in the material safety data sheets. Manufacturers should declare all components of dental composites to identify these substances that may result in allergic or undesirable side effects for patients and dental staff.

Implant Health in Treated Periodontitis Patients: A Systematic Review and Meta-Analysis.

BACKGROUND: The aim of this meta-analysis was to evaluate the role of a history of periodontitis on implant failure. The two main judgment criteria studied are peri-implantitis and the survival rate. The two secondary judgment criteria studied are the mean pocket depth and the mean peri-implant bone loss. METHODS: An electronic search was performed via five databases (MEDLINE, Embase, ScienceDirect, LILACS and the Cochrane Library) and was supplemented by manual searching. The search was undertaken in June 2024. RESULTS: Of 10 775 potentially eligible articles, 8 were included in the qualitative analysis and 10 in the quantitative synthesis. CONCLUSIONS: This meta-analysis suggests that a history of periodontitis has a significant impact on the rate of peri-implantitis, survival rate, mean bone loss and pocket depth.

Evaluation of Mental Foramen with Cone Beam Computed Tomography: A Systematic Review of Literature.

PURPOSE: The aim of this systematic review is to assess whether the anatomy of mental foramen is precisely evaluable with cone beam computed tomography (CBCT) before implantation in humans. METHODS: A systematic review was carried out to evaluate the anatomy of mental foramen (size, position, symmetry, anterior loop, and accessory mental foramen or multiple mental foramina). According to Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines, an electronic search of three databases (Medline, Web of Science, and Cochrane Library) was undertaken until June 2020 and was supplemented by manual searching. Two reviewers will independently perform the processes of study inclusion, data extraction, and quality assessment. Systematic reviews, studies about children, and case reports were excluded. Only studies using CBCT to do preoperative evaluation were selected. RESULTS: From 728 potentially eligible articles, 72 were included in the qualitative analysis and quantitative synthesis. This systematic review provided an assessment of the anatomy of the mental foramen. The mental foramen was located mostly between the two premolars (between 50.4% and 61.95%) or apically to the second premolar (from 50.3% to 57.9%). The mean diameter of the mental foramen was bigger in males than in females; the difference between them could reach 0.62 mm. The anterior loop seemed to be longer in males (between 0.87 ± 1.81 and 7.25 ± 2.02 mm) than in females (between 0.81 ± 1.18 and 6.52 ± 1.63 mm) and with the presence of teeth (from 0.91 ± 1.18 to 2.55 ± 1.28 for dentate people and from 0.25 ± 0.61 to 2.40 ± 0.88 mm for edentate population). The anterior loop and the accessory mental foramina were detected more frequently with CBCT than panoramic X-ray: only between 0.0 and 48.6% AMFs detected with CBCT were also seen with panoramic images. Clinical Significance. The mental foramen (MF) is an important landmark for local anesthesia and surgical and implantology procedures. Its location, morphology, and anatomical variations need to be considered to avoid mental nerve injury. The aim of this review is to evaluate the mental foramen using CBCT through a systematic literature review to improve knowledge of this complex area for the clinician.

Cytotoxicity evaluation of dental and orthodontic light-cured composite resins.

INTRODUCTION: The aim of this study was to determine the cytotoxicity of light-cured composite resins (Clearfil ES-2, Clearfil ES Flow, Filtek Supreme XTE, Grengloo, Blugloo, Transbond XT, and Transbond LR) then to assess leachable components in contact with human gingival fibroblasts (GFs) and to quantity detected bisphenol A (BPA). METHODS: Light-cured composite resin discs were immersed for 24 hours in gingival fibroblastic medium (n = 3 for each product) and in control medium (n = 2 for each product) contained in plate. Cytotoxicity of the products (n = 95) was determined by the measure of cell viability using MTT assay after reading the optical densities of the plates. The analysis of leachable components was done by gas phase chromatography and mass spectrometry (GC-MS) and detected BPA was quantified. The limit of quantification was 0.01 µg/mL. Statistical analyses were performed by using IBM SPSS Statistics 20 and Kruskal-Wallis and Mann-Whitney U-tests were applied. RESULTS: Cell viabilities were between 85 and 90%. Many chemical compounds including triethylene glycol dimethacrylate (TEGDMA) and BPA were identified. The average concentrations were 0.67 µg/mL ± 0.84 in the control medium and 0.73 µg/mL ± 1.05 in the fibroblastic medium. Filtek Supreme XTE presented the highest concentration of BPA with 2.16 µg/mL ± 0.65 and Clearfil ES Flow presented the lowest with 0.25 µg/mL ± 0.35. No BPA was detected with Transbond XT and Transbond LR. Clearfil ES Flow, Filtek Supreme XTE, Grengloo and Transbond LR presented residual TEGDMA. CONCLUSIONS: Light-cured composite resins are slightly cytotoxic opposite GFs and release many components including BPA and TEGDMA. Clinical precautions should be taken to decrease the release of these monomers.

Tissue Engineering and Three-Dimensional Printing in Periodontal Regeneration: A Literature Review.

The three-dimensional printing of scaffolds is an interesting alternative to the traditional techniques of periodontal regeneration. This technique uses computer assisted design and manufacturing after CT scan. After 3D modelling, individualized scaffolds are printed by extrusion, selective laser sintering, stereolithography, or powder bed inkjet printing. These scaffolds can be made of one or several materials such as natural polymers, synthetic polymers, or bioceramics. They can be monophasic or multiphasic and tend to recreate the architectural structure of the periodontal tissue. In order to enhance the bioactivity and have a higher regeneration, the scaffolds can be embedded with stem cells and/or growth factors. This new technique could enhance a complete periodontal regeneration. This review summarizes the application of 3D printed scaffolds in periodontal regeneration. The process, the materials and designs, the key advantages and prospects of 3D bioprinting are highlighted, providing new ideas for tissue regeneration.

Silanization of Chitosan and Hydrogel Preparation for Skeletal Tissue Engineering.

Tissue engineering is a multidisciplinary field that relies on the development of customized biomaterial to support cell growth, differentiation and matrix production. Toward that goal, we designed the grafting of silane groups onto the chitosan backbone (Si-chito) for the preparation of in situ setting hydrogels in association with silanized hydroxypropyl methylcellulose (Si-HPMC). Once functionalized, the chitosan was characterized, and the presence of silane groups and its ability to gel were demonstrated by rheology that strongly suggests the presence of silane groups. Throughout physicochemical investigations, the Si-HPMC hydrogels containing Si-chito were found to be stiffer with an injection force unmodified. The presence of chitosan within the hydrogel has demonstrated a higher adhesion of the hydrogel onto the surface of tissues. The results of cell viability assays indicated that there was no cytotoxicity of Si-chito hydrogels in 2D and 3D culture of human SW1353 cells and human adipose stromal cells, respectively. Moreover, Si-chito allows the transplantation of human nasal chondrocytes in the subcutis of nude mice while maintaining their viability and extracellular matrix secretory activity. To conclude, Si-chito mixed with Si-HPMC is an injectable, self-setting and cytocompatible hydrogel able to support the in vitro and in vivo viability and activity of hASC.

Radiopacity of Coronary Stents, an In Vitro Comparative Study.

PURPOSE: Interventional cardiology devices and especially stents are constantly evolving. A good radiopacity is essential to properly position the stent and to reduce the risk of complications during percutaneous coronary intervention (PCI). We wanted to assess the radiopacity of coronary stents. METHODS: 9 stents were evaluated. Stents were deployed in a silicon bifurcation model and several pulsed fluoroscopy acquisitions (7.5 and 15 pulses/s) of each device were performed in a catheterization laboratory. Quantitative radiopacity assessment was performed using a radiopacity visual scale and qualitative radiopacity assessment was performed by showing the images to three experienced operators, single-blind. RESULTS: Our study showed statistically significant differences between stents regarding radiopacity assessed in a quantitative analysis (p < 0.000001) or a qualitative analysis (p < 0.000001), whether the acquisitions were made in 7.5 or 15 pulses/s. Resolute Onyx and Synergy were the most radio-opaque in both qualitative and qualitative analysis. Moreover, there was a statistically significant correlation between the radiopacity of stents, their strut thickness (p < 0.0001) and the presence of platinum in their metallic alloy (p < 0.0001). CONCLUSION: This study highlighted significant differences in the radiopacity of coronary stents deployed in a bench test model. The strut thickness and the presence of platinum increased the radiopacity.

Variability of slot size in orthodontic brackets.

Objective: The accuracy of the information incorporated into brackets is a determining factor for the efficacy of torque applied to teeth. The aim of this study was to compare the dimensions of a bracket's slots with the nominal values announced by the manufacturer. Materials and methods: A total of 730 maxillary right central brackets manufactured by seven companies (Dentsply Gac, American Orthodontics, Rocky Mountain Orthodontics, GC Orthodontics, 3M Unitek, and Dentaurum) were studied. The sample included 0.018 × 0.025 and 0.022 × 0.028 in., metal and ceramic, conventional and self-ligating brackets. Images were obtained with an Olympus BX51 optical microscope. Slot dimensions were measured at the base and at the face on both mesial and distal sides using ImageJ software. Data were analyzed using Wilcoxon, sign tests, two- and three-way ANOVA, and Tukey's tests. Intraclass correlation coefficient was employed to assess the intraobserver and interobserver variability. The threshold for statistical significance was p ≤ .05. Results: Statistical analysis showed that the slot dimensions of 90% to 97% of studied brackets were significantly different from nominal values. In general, slot size was oversized, with a face size larger than the base size. Comparison between mesial and distal sides showed that up to 45% of the brackets were significantly asymmetrical. The manufacturer had a significant effect for base and face widths (p = .0001) and for length (p = .003). Conclusion: This study shows that a large proportion of measured brackets displays dimensional inaccuracies when compared with stated values. Clinically, the slot oversize and the divergence of slot walls cause an increase of wire-slot play, inducing a loss of torque control. Practitioners cannot fully trust the precision of used appliances and should be aware that adjustments could be needed in the finishing stages of the treatment.

The use of laser Doppler flowmetry to evaluate oral soft tissue blood flow in humans: A review.

The objective of this work is to define the conditions for improving the use of laser Doppler flowmetry (LDF) and to determine the limits for the use of this technique. This article systematically reviews the literature on the evaluation of oral soft tissue blood microcirculation by LDF. We analysed the available literature through October 2016 using the database resources Medline/PubMed, the Cochrane Oral Health Group Specialist Trials Register and the ISI Web of Knowledge. Several points emerged from this literature review The use of LDF involves specific constraints; however, the influence of different factors (temperature, tobacco, pressure etc.) must be adequately controlled when using LDF. LDF measurements of soft tissue within the oral cavity vary depending on the anatomical site. In dentistry, LDF can be used to track healing progress in periodontal surgery and to diagnose vascular flow changes in the connective tissue of mucosae covered by a removable prosthesis at an early stage prior to the onset of clinical inflammation signs.

[Bone substitutes]. / Substituts osseux.

Bone substitutes, used to fill a defect after a surgery or a trauma, provide a mechanical support and might induce bone healing. They constitute an alternative to autogenous bone grafts, the 'gold standard' which remains the reference despite its risk of postoperative complications. The clinician choice of a bone substitute is based on the required bone volume, the handling (injectability, malleability) and mechanical properties (setting time, viscosity, resorbability among others) of the material. Bone substitutes are commonly used in orthopedic surgery, neurosurgery, stomatology and dental applications. Their use increases steadily, with the recent clinical development of injectable forms. In addition, novel technologies by subtractive or additive techniques allow today the production of controlled architecture materials. Here, we present a bone substitutes classification according to their origin (natural or synthetic) and chemical composition, and the most common use of these substitutes.

Diagnosis of skull fractures according to postmortem interval: an experimental approach in a porcine model.

Most studies on fracture morphology of fresh or dry bones, specifically skull bones, have a limited focus, and they are often based on observations rather than experimental tests. This study characterized pig cranial fractures sustained under known impact conditions. An impact machine (mobile carriage guided by columns) was used to perform a fracture on each skull. Impacts were performed at the same energy level on fresh and dry bones, with two types of impactor: a sharp striker (n = 50) and a blunt striker (n = 50). We found distinct features under different conditions, including osseous flakes on fresh bones, 90° fracture angles on dry bones, and more fractures with greater fragmentation on dry bones. These features highlighted the effects of time on perimortem fracture characteristics and the importance of bone storage conditions in the study of fracture genesis.