Effects of insertion torque values on the marginal bone loss of dental implants installed in sheep mandibles

The aim of the present in vivo study was to analyze and compare the effects on the crestal bone healing of two different implant macrogeometries installed in fresh socket areas and in normal bone areas with different insertion torque values. Two implant macrogeometries were used in the present study, DuoCone implant (DC) and Maestro implant (MAE), forming four groups: group DCws, in which the implants were installed in healing bone (without a socket); group DCfs, in which the implants were installed in post-extraction areas (fresh sockets); group MAEws, in which the implants were installed in healing bone (without a socket); group MAEfs, in which the implants were installed in post-extraction areas (fresh sockets). After 30 and 90 days of implantations in the bilateral mandibles of 10 sheep, eighty implants were evaluated through digital X-ray images and histologic slices. The crestal bone position in relation to the implant platform shoulder was measured and compared. The measured insertion torque was 47.2 ± 4.69 Ncm for the DCws group, 43.4 ± 4.87 Ncm for the DCfs group, 29.3 ± 3.16 Ncm for the MAEws group, and 27.7 ± 4.41 Ncm for the MAEfs group. The radiographic mesio-distal and histological bucco-lingual analyses showed significantly greater vertical bone loss in the implants installed with high torque (DC groups) in comparison to the implants installed with a low torque (MAE groups) (p < 0.05), at both evaluation times. In general, low insertion torque values (Maestro implants) showed better results of MBL when compared to implants installed with higher torque values (Duo Cone implants). Moreover, our results showed that the implants installed in the sites without sockets showed a less MBL in comparison with the implants installed in sites of fresh sockets.

Light-Triggered Adhesive Silk-Based Film for Effective Photodynamic Antibacterial Therapy and Rapid Hemostasis

Successful control of massive hemorrhage in deep wounds with irregular shape and low elasticity still remains great challenges in the clinic. As the wound sites are usually at risk of bacterial infection, it is necessary to design an ideal hemostatic agent with rapid hemostasis and excellent antibacterial activity. In this study, we developed a light responsive hemostatic film for effective handling of liver bleeding with promising photodynamic therapy against S. aureus onnear infrared (NIR) irradiation. Based on silk fibroin, the film exhibited desirable biocompatibility and mechanical property as a hemostat tape. Significantly, the film tape achieved excellent tissue adhesion and hemostasis in vivo within 2 min of UV exposure, which would have a great potential as a multifunctional biomedical material in the field of tissue repair such as wound healing, bone repair, and nerve regeneration.

Synthesis, Characterization and Biomedical Application of Silver Nanoparticles

Silver nanoparticles (AgNPs) have been employed in various fields of biotechnology due to their proven properties as an antibacterial, antiviral and antifungal agent. AgNPs are generally synthesized through chemical, physical and biological approaches involving a myriad of methods. As each approach confers unique advantages and challenges, a trends analysis of literature for the AgNPs synthesis using different types of synthesis were also reviewed through a bibliometric approach. A sum of 10,278 publications were analyzed on the annual numbers of publication relating to AgNPs and biological, chemical or physical synthesis from 2010 to 2020 using Microsoft Excel applied to the Scopus publication database. Furthermore, another bibliometric clustering and mapping software were used to study the occurrences of author keywords on the biomedical applications of biosynthesized AgNPs and a total collection of 224 documents were found, sourced from articles, reviews, book chapters, conference papers and reviews. AgNPs provides an excellent, dependable, and effective solution for seven major concerns: as antibacterial, antiviral, anticancer, bone healing, bone cement, dental applications and wound healing. In recent years, AgNPs have been employed in biomedical sector due to their antibacterial, antiviral and anticancer properties. This review discussed on the types of synthesis, how AgNPs are characterized and their applications in biomedical field.

Combat Lesion in Triceratops: Histological and Chemical Diagnosis

In the collective imagination derived from scientific and popular literature, Triceratops often faced each other in combat. Thus, from the second half of the twentieth century, these ceratopsids were described as pugnacious animals. This arises primarily from the interpretation of extracranial fenestrae in ceratopsids being the result of combat trauma. However, the diagnosis of the traumatic nature of these anatomical variants of their neck frill requires evidence of bone healing and remodelling by microscopy analysis. Here, we present the case of the Triceratops horridus known as Big John, which is one of the largest specimens discovered in the Hell Creek Formation (Upper Cretaceous; MT, USA). Its right squamosal bone shows an extrafenestra with irregular margins and signs of inflammation. Microscopy analysis revealed newly formed and healing bone, with histological signs typical of the bone remodelling phase. Chemical analysis revealed sulphur that was derived from glucosaminoglycans and sulphated glycoproteins of the preosseous osteoid substance present in the healing phases of a bone trauma. Histological and microanalytical analyses confirm that the squamosal fenestra of Big John is the result of a traumatic event, which might indeed have occurred during combat with another Triceratops.

A Review on the Application of Silver Nanoparticles in Oral and Maxillofacial Surgery

Silver nanoparticles (AgNPs) have been taken advantage of in dentistry because of their good antibacterial resistance and self-sustaining potential. However, in oral and maxillofacial surgery and implantology, there is a lesser amount of evidence. The few pieces of evidence need to be accentuated for possible amplification of its use in the dental setting. AgNPs in oral and maxillofacial surgery can be used in wound healing, bone healing, extractions, guided tissue regeneration, apical surgeries, oral cancer, and dental implants. This review aims to feature the utilization and application of AgNPs in oral and maxillofacial surgery and implant dentistry, emphasizing its need for potential future development in clinical settings.

Antioxidant Potential of Epigallocatechin-3-gallate, Ascorbic Acid, and Sodium Ascorbate in Solution and Gel Forms by 2,2-diphenyl-1-picrylhydrazyl (DPPH) Assay

Background: Free radicals are molecules without any electron pairs, unstable, and highly reactive. Antioxidants are needed to reduce free radicals. Antioxidants provide various benefits in dentistry as a preventive agent for caries, healing, bone formation, mouthwash, preventive and therapeutic cancer, and reduction of periodontal disease progressions. Additionally, research on antioxidants is still undergone due to the existence of free radical residues on bleached teeth. Epigallocatechin-3-gallate (EGCG), ascorbic acid (AA), and sodium ascorbate (SA) are ingridients that have antioxidant properties. Antioxidants can be in two forms solution and gel. Solutions have a higher substance releasing power than gel. Gel is extremely adhesive, so it does not flow easily. Meanwhile, solutions are rather unstable because it flows easily. Antioxidant activities were evaluated with 2,2-diphenyl-1-picrylhydrazyl (DPPH) Assay method. Purpose: Analyzing through literature reviews the potential antioxidants of EGCG, AA, and SA in solution and gel forms by DPPH Assay. Reviews: There were eight journal articles used in this review. The first article described antioxidant solutions in which EGCG was higher than sodium ascorbate. The second article showed that antioxidant gel EGCG was lower than sodium ascorbate. The third journal explained that ascorbic acid was higher than sodium ascorbate both in solution and gel forms. The other articles provided some information about the antioxidant activity percentages of EGCG, SA, and AA in the forms of gel and solutions by DPPH assay. Conclusion: EGCG has a higher antioxidant activity than SA, but it is lower when compared to AA in both solution and gel forms by DPPH assay.

Pearl Powder—An Emerging Material for Biomedical Applications: A Review

Pearl powder is a well-known traditional Chinese medicine for a variety of indications from beauty care to healthcare. While used for over a thousand years, there has yet to be an in-depth understanding and review in this area. The use of pearl powder is particularly growing in the biomedical area with various benefits reported due to the active ingredients within the pearl matrix itself. In this review, we focus on the emerging biomedical applications of pearl powder, touching on applications of pearl powder in wound healing, bone repairing, treatment of skin conditions, and other health indications.

Bilateral Atypical Femoral Fracture(AFF) After Teriparatide and Subsequent Anti-Resorptive Therapy: A Management Dilemma

Introduction: Femoral fractures carry devastating morbidity for long term ambulation. Atypical femoral fractures (AFF) are uncommon, and bilateral AFFs are more rare with added post-fracture limitations. We report two patients with bilateral AFFs despite receiving teriparatide (TPTD). Case 1: A 72 y.o. Filipino lady with osteoporosis since late 1990 was treated with bisphosphonates (BP) intermittently over 25 years with drug holidays for dental work. She stopped alendronate in mid-2013 and continued raloxifene. She suffered a spontaneous left mid-femur AFF in June, 2015 that was treated with intramedullary (IM) rod and nailing. In July, 2015 she started TPTD 20 mcg daily for 23 months until May, 2017. Alendronate was restarted weekly. In December, 2018 she developed right thigh and hip prodromal pain without x-ray changes. In April, 2019 (46 months after the left AFF and 23 months after TPTD), she sustained a spontaneous right sub-trochanteric AFF. BP was stopped. After IM rod and nailing, she began a second course of TPTD. Case 2: 72 y.o Caucasian lady with osteoporosis since 2000 was treated with alendronate until April, 2006. She was switched to daily TPTD for 22 months from May, 2006 to March, 2008. Oral BP was resumed in April, 2008. She suffered a left AFF in November, 2009; BP was stopped in March, 2010. In July, 2010 she sustained a right AFF (9 months after the left AFF and 28 months post-TPTD). Each spontaneous AFF occurred after prodromal pain, and each was treated with IM rod placement with nailing. She received BP infusion in 2011 and TPTD from March, 2012 to March, 2014. DXA scan in 2020 showed lumbar spine osteopenia. She currently takes calcium and Vit D supplementation. Discussion: TPTD is reported as a potential treatment for enhancing AFF healing, bone mineral density and pain resolution. The expectation is that it might prevent contralateral AFF. No randomized studies of prevention of AFF with TPTD exist. Available reports show variable results. Prolonged presence of BP in bone may contribute to this variation. We identified 7 reported AFF patients treated with TPTD who then developed a contralateral AFF. We found 2 patients with new AFF after TPTD as in our Case 2. In all cases there was previous exposure to BP. Perhaps the 28–30% risk of a contralateral AFF within 4 years in the setting of BP is irremediable. Conclusion: TPTD increases healing of AFF in some reports, but prevention of an initial or further AFF has not been well documented. Our 2 patients and 9 others reported suggest a possible subset with increased sensitivity to the effect of BP and increased AFF risk. The best choice after TPTD is unclear, but it may include permanent removal of anti-resorptive agents. The anti-sclerostin antibody romosozumab also has been associated with AFF. Choices are limited for these patients other than excellent surgical care, adequate calcium/vitamin D intake, and periodic imaging as symptoms dictate.

3D Bioprinted Bacteriostatic Hyperelastic Bone Scaffold for Damage-Specific Bone Regeneration

Current strategies for regeneration of large bone fractures yield limited clinical success mainly due to poor integration and healing. Multidisciplinary approaches in design and development of functional tissue engineered scaffolds are required to overcome these translational challenges. Here, a new generation of hyperelastic bone (HB) implants, loaded with superparamagnetic iron oxide nanoparticles (SPIONs), are 3D bioprinted and their regenerative effect on large non-healing bone fractures is studied. Scaffolds are bioprinted with the geometry that closely correspond to that of the bone defect, using an osteoconductive, highly elastic, surgically friendly bioink mainly composed of hydroxyapatite. Incorporation of SPIONs into HB bioink results in enhanced bacteriostatic properties of bone grafts while exhibiting no cytotoxicity. In vitro culture of mouse embryonic cells and human osteoblast-like cells remain viable and functional up to 14 days on printed HB scaffolds. Implantation of damage-specific bioprinted constructs into a rat model of femoral bone defect demonstrates significant regenerative effect over the 2-week time course. While no infection, immune rejection, or fibrotic encapsulation is observed, HB grafts show rapid integration with host tissue, ossification, and growth of new bone. These results suggest a great translational potential for 3D bioprinted HB scaffolds, laden with functional nanoparticles, for hard tissue engineering applications.

Increased Mesenchymal Stem Cell Functionalization in Three-Dimensional Manufacturing Settings for Enhanced Therapeutic Applications

Mesenchymal stem/stromal cell (MSC) exist within their in vivo niches as part of heterogeneous cell populations, exhibiting variable stemness potential and supportive functionalities. Conventional extensive 2D in vitro MSC expansion, aimed at obtaining clinically relevant therapeutic cell numbers, results in detrimental effects on both cellular characteristics (e.g., phenotypic changes and senescence) and functions (e.g., differentiation capacity and immunomodulatory effects). These deleterious effects, added to the inherent inter-donor variability, negatively affect the standardization and reproducibility of MSC therapeutic potential. The resulting manufacturing challenges that drive the qualitative variability of MSC-based products is evident in various clinical trials where MSC therapeutic efficacy is moderate or, in some cases, totally insufficient. To circumvent these limitations, various in vitro/ex vivo techniques have been applied to manufacturing protocols to induce specific features, attributes, and functions in expanding cells. Exposure to inflammatory cues (cell priming) is one of them, however, with untoward effects such as transient expression of HLA-DR preventing allogeneic therapeutic schemes. MSC functionalization can be also achieved by in vitro 3D culturing techniques, in an effort to more closely recapitulate the in vivo MSC niche. The resulting spheroid structures provide spatial cell organization with increased cell–cell interactions, stable, or even enhanced phenotypic profiles, and increased trophic and immunomodulatory functionalities. In that context, MSC 3D spheroids have shown enhanced “medicinal signaling” activities and increased homing and survival capacities upon transplantation in vivo. Importantly, MSC spheroids have been applied in various preclinical animal models including wound healing, bone and osteochondral defects, and cardiovascular diseases showing safety and efficacy in vivo. Therefore, the incorporation of 3D MSC culturing approach into cell-based therapy would significantly impact the field, as more reproducible clinical outcomes may be achieved without requiring ex vivo stimulatory regimes. In the present review, we discuss the MSC functionalization in 3D settings and how this strategy can contribute to an improved MSC-based product for safer and more effective therapeutic applications.