3,636 research outputs found
b \bar b b\bar b production in proton-nucleus collisions at the LHC
A sizable rate of events, with several pairs of -quarks produced
contemporarily by multiple parton interactions, may be expected at very high
energies as a consequence of the large parton luminosities. The production
rates are further enhanced in hadron-nucleus reactions, which may represent a
convenient tool to study the phenomenon. We compare the different contributions
to production, due to single and double parton
scatterings, in collisions of protons with nuclei at the CERN-LHC.Comment: 13 pages, 4 figure
Synthetic blocks for bone regeneration : A systematic review and meta-analysis
This systematic review is aimed at evaluating the effectiveness of synthetic block materials for bone augmentation in preclinical in vivo studies. An electronic search was performed on Pubmed, Scopus, EMBASE. Articles selected underwent risk-of-bias assessment. The outcomes were: new bone formation and residual graft with histomorphometry, radiographic bone density, soft tissue parameters, complications. Meta-analysis was performed to compare new bone formation in test (synthetic blocks) vs. control group (autogenous blocks or spontaneous healing). The search yielded 214 articles. After screening, 39 studies were included, all performed on animal models: rabbits (n = 18 studies), dogs (n = 4), rats (n = 7), minipigs (n = 4), goats (n = 4), and sheep (n = 2). The meta-analysis on rabbit studies showed significantly higher new bone formation for synthetic blocks with respect to autogenous blocks both at four-week (mean difference (MD): 5.91%, 95% confidence intervals (CI): 1.04, 10.79%, p = 0.02) and at eight-week healing (MD: 4.44%, 95% CI: 0.71, 8.17%, p = 0.02). Other animal models evidenced a trend for better outcomes with synthetic blocks, though only based on qualitative analysis. Synthetic blocks may represent a viable resource in bone regenerative surgery for achieving new bone formation. Differences in the animal models, the design of included studies, and the bone defects treated should be considered when generalizing the results. Clinical studies are needed to confirm the effectiveness of synthetic blocks in bone augmentation procedures
Adjunctive Use of Plasma Rich in Growth Factors for Improving Alveolar Socket Healing: A Systematic Review
Purpose: The purpose of this study was to determine if the adjunctive use of plasma rich in
growth factors in post-extraction sites could be beneficial in terms of hard/soft tissue healing and
patient\u2019s comfort.
Materials and Methods: An electronic search was performed on MEDLINE, EMBASE, Scopus,
and CENTRAL. Only controlled clinical trials or randomized clinical trials that used plasma rich
in growth factors in the test group were included. The primary outcomes were: pain assessment,
complications and adverse events; secondary outcomes were hard tissue healing, bone
remodelling, soft tissue healing.
Results: Eight comparative studies (5 RCTs) were included. Four studies had a split-mouth
design. 614 teeth were extracted in 338 patients. Only qualitative analysis could be done.
Postoperative pain and the incidence of complications like alveolar osteitis was consistently
lower in the test group. Hard tissue healing, evaluated by clinical, radiographic, histological and
histomorphometric technique showed results significantly better for the test group in almost all
studies. Better epithelization, keratinized tissue thickness and healing score were also reported.
Conclusion: Plasma rich in growth factors may bring advantages in some relevant clinical and
radiographic outcomes following tooth extraction, such as bone density and soft tissue healing.
It could also represent a useful tool for reducing adverse events, complications and patients\u2019
discomfort, however still not quantifiable
Self-assessed neurological disturbances after surgical removal of impacted lower third molar: a pragmatic prospective study on 423 surgical extractions in 247 consecutive patients
OBJECTIVES:
The aim of this study was to assess the combined role of current radiographic risk indicators and patient age in predicting lower lip sensitivity disturbances after surgical removal of impacted lower third molars. The question was which combinations indicate low or high risk.
MATERIALS AND METHODS:
A prospective study was implemented involving 247 consecutive outpatients who underwent 423 surgical extractions. The predictor variables were patient age and risk indicators observed on panoramic radiographs. The outcome variable was the incidence of self-assessed lip sensitivity alterations. The extractions were subdivided into four groups according to the predictors.
RESULTS:
Two hundred forty-five teeth were extracted in patients younger than 25 years and 178 in patients 25 years old or older; radiographic risk indicators were associated with 226 out of 423 teeth (53.43%). No permanent neurological damage was observed. Transient lip sensitivity alterations were observed in five cases (1.18%; 95% confidence interval\u2009=\u20090.4 to 2.7%), all in the older group with radiographic risk indicators.
CONCLUSIONS:
The data indicate a low overall incidence of transient lip sensitivity impairment that occurred only in the presence of radiographic risk indicators in patients aged 65\u200925 years.
CLINICAL RELEVANCE:
Informed consent should include the possibility of inferior alveolar nerve injury in mature patients with radiographic risk indicators. Prophylactic removal of impacted teeth with radiographic signs of risk may be indicated when the patient is not yet aged 25 years
Scale Factor in Double Parton Collisions and Parton Densities in Transverse Space
The scale factor , which characterizes double parton collisions
in high energy hadron interactions, is a direct manifestation of the
distribution of the interacting partons in transverse space, in such a way that
different distributions give rise to different values of in
different double parton collision processes. We work out the value of the scale
factor in a few reactions of interest, in a correlated model of the
multi-parton density of the proton recently proposed.Comment: 10 pages, 2 figure
Gene Delivery Therapeutics in the Treatment of Periodontitis and Peri-Implantitis : A State of the Art Review
Background: Periodontal disease is a chronic inflammatory condition that affects supporting tissues around teeth, resulting in periodontal tissue breakdown. If left untreated, periodontal disease could have serious consequences; this condition is in fact considered as the primary cause of tooth loss. Being highly prevalent among adults, periodontal disease treatment is receiving increased attention from researchers and clinicians. When this condition occurs around dental implants, the disease is termed peri-implantitis. Periodontal regeneration aims at restoring the destroyed attachment apparatus, in order to improve tooth stability and thus reduce disease progression and subsequent periodontal tissue breakdown. Although many biomaterials have been developed to promote periodontal regeneration, they still have their own set of disadvantages. As a result, regenerative medicine has been employed in the periodontal field, not only to overcome the drawbacks of the conventional biomaterials but also to ensure more predictable regenerative outcomes with minimal complications. Regenerative medicine is considered a part of the research field called tissue engineering/regenerative medicine (TE/RM), a translational field combining cell therapy, biomaterial, biomedical engineering and genetics all with the aim to replace and restore tissues or organs to their normal function using in vitro models for in vivo regeneration. In a tissue, cells are responding to different micro-environmental cues and signaling molecules, these biological factors influence cell differentiation, migration and cell responses. A central part of TE/RM therapy is introducing drugs, genetic materials or proteins to induce specific cellular responses in the cells at the site of tissue repair in order to enhance and improve tissue regeneration. In this review, we present the state of art of gene therapy in the applications of periodontal tissue and peri-implant regeneration. Purpose: We aim herein to review the currently available methods for gene therapy, which include the utilization of viral/non-viral vectors and how they might serve as therapeutic potentials in regenerative medicine for periodontal and peri-implant tissues
Cone-beam computed tomography accuracy in pulp chamber size evaluation: An ex vivo study
This study aimed to assess ex vivo the accuracy of cone-beam computed tomography (CBCT), as compared to operative microscope, for evaluating pulp chamber size. A total of forty teeth were extracted for periodontal reasons and a horizontal section was done at the most apical level of the cement-enamel junction. The pulp chamber was photographed using a digital camera connected to an optical microscope. Then, the tooth was scanned with CBCT and the horizontal slide matching the anatomical section of pulp chamber was digitally stored. The pulp chamber section area was measured through image analysis software. The two methods provided similar results, either for monoradicular (P = 0.14) or multiradicular teeth (P = 0.93). Correlation was statistically significant (P < 0.0001), being the coefficient r = 0.89 and 0.94 for monoradicular and multiradicular teeth, respectively. Conclusively, CBCT is suitable for pulp chamber morphology evaluation. However, it has limitations in detecting the anatomical variability of small branches in root canal system
Relation between serum creatinine and body mass index in elite athletes of different sport disciplines
Objectives: To document the relation between serum creatinine concentration and body mass index in elite athletes from five different sports, and to study potential differences among athletes performing different sports with different features and requirements. Methods: Before the start of the competitive season, serum creatinine was measured in 151 elite athletes from five different sports: rugby (n = 44), soccer (n = 27), alpine skiing (n = 34), sailing (n = 22), cycling (n = 24). Pearson's correlation analysis was used to evaluate the relation between serum creatinine and body mass index (BMI). Analysis of variance and unpaired Student's t test were used to compare creatinine concentration and BMI in different sport disciplines. Results: In the whole group of athletes, a positive correlation between serum creatinine and BMI was found (r = 0.48, p<0.001). Significant differences in creatinine concentration and BMI were found between athletes competing in different sports: their mean (SD) values were respectively 1.31 (0.12) mg/dl and 28.83 (2.41) for rugby players, 1.27 mg/dl (0.10) and 23.10 (1.01) for soccer players, 1.15 (0.11) mg/dl and 25.8 (1.50) for skiers, 1.08 (0.11) mg/dl and 26.93 (2.36) for sailors, and 0.91 (0.07)mg/dl and 21.33 (1.21) for cyclists. Conclusions: There is a correlation between creatinine concentration and BMI in elite athletes competing in different sports characterised by different kinds of training, competitive season, and involvement of aerobic and anaerobic metabolism. Interpretation of creatinine concentrations in male athletes should consider professional status as well as the specific sport performed. All athletes should be monitored with consecutive creatinine assessments, using as the baseline the concentration determined before the start of training and the competitive season, but taking into consideration the specific sport performed and the BMI until equations that include creatinine and factors that affect its concentration are used
Zygomatic Implant Survival in 9 Ectodermal Dysplasia Patients with 3.5 to 7-year Follow Up
Ectodermal dysplasia syndrome is a complex group of genetic disorders identified by the abnormal development of the ectodermal structures. The aim of this retrospective clinical case series report was to evaluate the outcomes of the ectodermal dysplasia syndrome patients that underwent zygomatic implant surgery.
Materials and Methods: A total of 9 ectodermal dysplasia syndrome patients aged between 21 and 56 years (mean age 36.8) with severely atrophic maxilla were included in this study. All the patients were treated with a total of 19 zygomatic implants. The mean follow-up of the patients was 55 months (with a range of 44\u201384 months). The implant survival rate was evaluated as a primary outcome. The intra- and postoperative
complications were evaluated as additional criteria for success.
Results: The overall implant survival rate was 100% without any complications. Final or provisional prosthesis was delivered on the same day of surgery, which resulted in an improvement of the quality of life of the patients.
Conclusion: According to the results of this study, zygomatic surgery can be considered
as a viable and safe alternative to conventional treatment modalities for oral
rehabilitation of ectodermal dysplasia syndrome patients
Production and detection of doubly charmed tetraquarks
The feasibility of tetraquark detection is studied. For the cc\bar{u}\bar{d}
tetraquark we show that in present (SELEX, Tevatron, RHIC) and future
facilities (LHCb, ALICE) the production rate is promising and we propose some
detectable decay channels.Comment: 6 pages, 5 figure
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