Maria Cristina Manzanares-Céspedes

Evaluation of bone loss in antibacterial coated dental implants: an experimental study in dogs

The aim of this study was to evaluate the in vivo effect of antibacterial modified dental implants in the first stages of peri-implantitis. Thirty dental implants were inserted in the mandibular premolar sites of 5 beagle dogs. Sites were randomly assigned to Ti (untreated implants, 10units), Ti_Ag (silver electrodeposition treatment, 10units), and Ti_TSP (silanization treatment, 10units). Coated implants were characterized by scanning electron microscopy, interferometry and X-ray photoelectron spectroscopy. Two months after implant insertion, experimental peri-implantitis was initiated by ligature placement. Ligatures were removed 2months later, and plaque formation was allowed for 2 additional months. Clinical and radiographic analyses were performed during the study. Implant-tissue samples were prepared for micro computed tomography, backscattered scanning electron microscopy, histomorphometric and histological analyses and ion release measurements. X-ray, SEM and histology images showed that vertical bone resorption in treated implants was lower than in the control group (P<0.05). This effect is likely due to the capacity of the treatments to reduce bacteria colonization on the implant surface. Histological analysis suggested an increase of peri-implant bone formation on silanized implants. However, the short post-ligature period was not enough to detect differences in clinical parameters among implant groups. Within the limits of this study, antibacterial surface treatments have a positive effect against bone resorption induced by peri-implantitis.

Chronic periodontitis, inflammatory cytokines, and interrelationship with other chronic diseases

ABSTRACT Periodontal diseases, such as chronic periodontitis, share common inflammatory risk factors with other systemic and chronic inflammatory disorders. Mucosal tissues, such as oral epithelia, are exposed to environmental stressors, such as tobacco and oral bacteria, that might be involved in promoting a systemic inflammatory state. Conversely, chronic disorders can also affect oral health. This review will summarize recent evidence for the interrelationship between chronic periodontitis and other prevalent chronic diseases such as cardiovascular diseases, diabetes, cancer and chronic respiratory diseases. The association with pregnancy is also included due to possible obstetric complications. We will focus on inflammatory cytokines such as TNF-alpha, IL-1, and IL-6, because they have been shown to be increased in patients with chronic periodontitis, in patients with chronic systemic diseases, and in patients with both chronic periodontitis and other chronic diseases. Therefore, an imbalance towards a proinflammatory immune response could underline a bidirectional link between chronic periodontitis and other chronic diseases. Finally, we highlight that a close coordination between dental and other health professionals could promote oral health and prevent or ameliorate other chronic diseases.

Mesenchymal Stem Cells Within Gelatin/CaSO4 Scaffolds Treated Ex Vivo with Low Doses of BMP-2 and Wnt3a Increase Bone Regeneration.

The delivery of osteogenic factors is a proven therapeutic strategy to promote bone regeneration. Bone morphogenetic proteins (BMPs) constitute a family of cytokines with well-known osteogenic and bone regenerative abilities. However, clinical uses of BMPs require high doses that have been associated with complications such as osteolysis, ectopic bone formation, or hematoma formation. In the present work, we sought to improve bone tissue engineering through an approach that combines the use of bone marrow-derived mesenchymal stem cells (BMMSCs), composite scaffolds, and osteoinductive agents. We employed a composite gelatin/CaSO4 scaffold that allows for an early expansion of seeded BMMSCs, which is followed by an increased level of osteogenic differentiation after 10 days in culture. Furthermore, this scaffold enhanced bone formation by BMMSCs in a mouse model of critical-sized calvarial defect. More importantly, our results demonstrate that ex vivo pretreatment of BMMSCs with low amounts of BMP-2 (2 nM) and Wnt3a (50 ng/mL) for 24 h cooperatively increases the expression of osteogenic markers in vitro and bone regeneration in the critical-sized calvarial defect mouse model. These data provide a strong rationale for the development of an ex vivo cooperative use of BMP-2 and Wnt3a. Osteogenic factor cooperation might be applied to reduce the required amount of growth factors while obtaining higher therapeutic effects.

Minimally invasive surgery for hallux valgus: a systematic review of current surgical techniques.

PurposeThe aim of this study was to systematically evaluate the available literature on minimally invasive surgical (MIS) treatment for hallux valgus and to provide an overview of the different surgical techniques.MethodsA systematic review of the literature available in MEDLINE, EMBASE, and the Cochrane database was performed including studies from January 2001 to 1 January 2018. The radiological outcomes (hallux valgus angle (HVA), intermetatarsal angle (IMA)), complication rates, and clinical outcome scores were evaluated. The MINORS scale was used to assess the methodological quality of included articles.ResultsOf 278 reviewed articles, 23 met the inclusion criteria. The included studies reported on the results of 2279 procedures in 1762 patients. The surgical techniques were divided into five categories: the Bosch technique, MIS Chevron-Akin, Reverdin-Isham procedure, Endolog system, and techniques involving distal soft tissue release and fixation. Results regarding radiological correction, clinical outcomes, and complication rate varied widely.ConclusionsThe studies included were of too little level of evidence to allow for data pooling or meta-analysis. There were too few studies on each surgical technique category to assess whether one is more effective than the rest. However, there is some evidence that the Chevron and Akin showed the most potential for improvement of the HVA and the Endolog for the IMA. An overall complication rate of 13% was obtained among all included studies. Appropriately powered randomized controlled trials, utilizing validated outcome measures, blinded assessors, and long-term follow up are needed to assess the efficacy of MIS techniques.

Vascular labeling of the head and neck vessels: technique, advantages and limitations

Background Vascular staining techniques have been used to describe the vascular structures of several anatomic areas. However, few reports have described this procedure in the head and neck region. This paper describes a head and neck vascular labeling procedure, and describes some of the technical complications that may occur. Material and Methods Fifteen specimen cadaver heads were prepared. After drying the vascular system, the internal carotid arteries were ligated and a solution with latex and a gelling agent was injected into the internal carotid arteries and external jugular veins. Two different colors were employed to differentiate arteries from veins. A total of 60ml latex was injected into each blood vessel. Subsequently, the specimens were refrigerated at 5°C for a minimum of 24 hours. Finally, a dissection was performed to identify the venous and arterial systems of the maxillofacial region. Results In most specimens, correct identification of the vascular structures (lingual artery, pterigoyd plexus, and the major palatal arteries, among others) was possible. However, in three heads a major technical problem occurred (the latex remained liquid), making the dissection unfeasible. Other minor complications such as latex obstruction due to the presence of atheromas were found in two further specimens. Conclusions The vascular labeling technique is a predictable, effective and simple method for analyzing the vascular system of the maxillofacial area in cadaveric studies, including vessels of reduced diameter or with an intraosseous course. This procedure can be especially useful to teach vascular anatomy to dental students and postgraduate residents. Key words:Blood vessels, vascular casting, vascular labeling, head and neck arteries, carotid arteries, jugular veins.

Short-term effects of strain produced on a split palatal screw-type hyrax appliance after rapid maxillary expansion: A clinical trial

INTRODUCTION The aim of this study was to establish an accumulated strain pattern in different parts of rapid maxillary expansion appliances and relate them to different vertical growth patterns. A clinical study was conducted of 40 patients with posterior crossbite who required rapid palatal expansion. METHODS Patients (mean age, 8.48 years) were recruited and treated at the Dental Hospital of Bellvitge, Hospitalet de Llobregat, Barcelona, Spain. Strain gauges were placed on the arms of the RME hyrax screw appliance to record deformation (strain) during the expansion and the retention phases for 75 days. A finite element model was used to place the gauge at the point where the strain was most expressed. The vertical coefficient of variation was used to classify the patients by their vertical growth pattern. P = 0.05 was considered to be statistically significant. RESULTS During the expansion phase, the highest values of accumulated strain were measured in the posterior part of the appliance for all facial biotypes, but these values passed to the anterior area at the end of the retention phase of the mesocephalic and brachycephalic patients. There was statistically significant difference in the strain of the posterior arms in accordance with the vertical growth pattern (P = 0.05) during the retention phase. At 75 days of retention, 61.25% of the arms had already begun to have strain dissipation. CONCLUSIONS The accumulated strain pattern in the rapid maxillary expansion appliance can vary depending on the facial biotype. In the future, orthodontists should try to tailor the activation and retention protocol based on each patients characteristics.