Choosing Implant Type for Using with Allogeneic Bone Ring Graft: Guidance of Stress Analysis-Part I

WOS: 000429609000006Objective: The aim of this study is to compare the stress distribution of three different implant macro design applied with allogeneic cancellous bone rings using three dimensional finite element analyses. Material and Methods: Finite element models of maxilla and mandible that augmented with allogeneic bone ring graft with implants were created. Vertical force of 100 N and oblique force of 100 N at 45 degrees angle were applied to three different (variable thread, cylindrical, standard thread) macro design implants. Results: Stress concentrations in the conjunction of neck of the implant and allogeneic bone ring were higher than other areas. The highest calculated values of Von Misses stresses were observed in standard thread implant with oblique loading in mandible model. In all models the highest stress values were greater for oblique loading compare to vertical loading. Discussion: Implant macro designs shows different distributions to implanted bone or graft. It should be considered when choosing an implant in the cases augmented with allogeneic cancellous bone ring.Kirikkale University Scientific Research Project Department [2015/104]This study supported by Kirikkale University Scientific Research Project Department. Project No: 2015/104

Prevalence of Dental Trauma and Mouthguard Awareness Among Weekend Warrior Soccer Players

Traumatic dental and facial injuries are frequent in sports and often cause esthetic, functional, psychological, and economic problems. The term "weekend warrior" is used to describe people who participate in physically demanding activities only on the weekend, or part-time. In this prospective cohort study, we examined the prevalence of dental trauma and knowledge of traumatic dental injuries among weekend warriors in Ankara, Turkey. A detailed questionnaire on mouthguard awareness and knowledge and experience of dental trauma was distributed to 1,007 weekend warrior athletes participating in a soccer tournament. The results showed that 9.8% of participants had experienced orofacial trauma, 21.7% were aware of mouthguards, 2.9% reported using mouthguards, 15.4% were aware of the field of sports dentistry, and 19.6% were aware of emergency treatment for dental trauma. Participation in sports, especially contact sports, greatly increases the risk of dental injury. The present results show that knowledge of traumatic orofacial and dental injuries is limited among weekend warriors. Public health authorities should develop relevant educational programs, including broad dissemination of information on the risks of traumatic dental injuries and methods for protection against such injuries.WoSScopu

Data Mining Framework for Power Quality Event Characterization of Iron and Steel Plants

In this paper, a power quality (PQ) knowledge discovery and modeling framework has been developed for both temporal and spatial PQ event data collected from transformer substations supplying iron and steel (I&S) plants. PQ event characteristics of various I&S plants have been obtained based on clustering and rule discovery techniques. The data are collected by the PQ analyzers, which detect the voltage sags, swells, and interruptions according to the IEC Standard 61000-4-30. The constructed clustering strategy ensures feasible system monitoring by reducing unmanageable number of PQ events collected by the distributed PQ measurement systems into event clusters count. An abstraction for event representation has been developed, through which representative feature bags are constructed for each event to be used in the similarity decisions. The developed model has been applied satisfactorily to PQ event data obtained from 15 major transformer substations supplying heavy industry zones of the transmission system up to a five-year time period and from two additional transformer substations supplying some other industrial zones, for comparison purposes. The developed PQ data mining framework, which is used to identify PQ event distributions based on the event descriptions given in the IEEE Std. 1159, provides a useful analysis and evaluation infrastructure for taking countermeasures against the most probable event occurrences, specific to those feeders of I&S plant transformer substations

Vitamin D receptor gene polymorphisms in multiple sclerosis disease: A case-control study

Multiple sclerosis (MS) is a common neurologic disorder that is a chronic inflammatory, demyelinating, and neurodegenerative disease of the central nervous system (CNS). Its etiology remains unknown. Several recent studies have found that decreased susceptibility to vitamin D deficiency is also associated with a decreased risk of MS. The role of vitamin D receptor (VDR) gene and its polymorphisms are highlighted as susceptible components. In this study, we aimed to identify the relationship between ApaI (rs7975232), BsmI (rs 1544410), and TaqI (rs731236) gene polymorphisms with MS. ApaI, BsmI, and TaqI genotypes were determined in 70 patients with MS and in 70 control subjects. DNA was isolated from blood samples, and then ApaI, BsmI and TaqI gene polymorphisms were identified using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay. The distribution of BsmI and TaqI polymorphisms did not show any significant differences in MS patients and controls; however, increased A allele of ApaI polymorphism was found in MS patients. Our findings suggest that the ApaI gene polymorphism might be associated with MS. Investigation of a larger population and functional work on these gene structures and function in MS patients are recommended

Comparison of the effects of subconjunctival and topical anti-VEGF therapy (bevacizumab) on experimental corneal neovascularization

Purpose: To compare the effects of bevacizumab applied either subconjunctivally or topically, in a rat model of corneal neovascularization induced by alkali burn. Methods: The right corneas of 24 Wistar-Albino rats were cauterized with silver nitrate sticks. The rats were divided randomly and equally into three groups: no treatment control (n=8), subconjunctival bevacizumab treatment (n=8), and topical bevacizumab treatment (n=8). Immediately following cauterization, the subconjunctival group was treated with a 0.05 ml (1.25 mg) bevacizumab subconjunctival injection. The topical group was treated with 10 mg/ml bevacizumab twice daily, and the control group received subconjunctival saline injections twice daily. The burn stimulus and neovascularization scores were evaluated using a technique previously described by Mahoney and Waterbury. Digital photographs were obtained before the eyes were enucleated and corneal sections were then analyzed by histopathology. Results: The mean burn stimulus score was 1.86 ± 0.6 and there was no statistical difference between the groups (p=0.730). The mean neovascularization scores in the subconjunctival and topical bevacizumab groups were statistically lower than the control group (p<0.05). The mean percentage area of corneal neovascularization was 82.5 ± 22.1 in the control group, 42.7 ± 15.0 in the subconjunctival group, and 55.8 ± 18.2 in the topical group. The differences between the control and treatment groups were statistically significant (p<0.05). Histopathology showed that the treatment groups presented less neovascularization, inflammation, and fibroblast activity than the control group (p<0.05). Conclusions: This study demonstrates that both subconjunctival and topical administrations of bevacizumab inhibit corneal neovascularization and decrease inflammation and fibroblast activity in a rat model of corneal neovascularization induced by alkali burn

Effect of Locally Applied bFGF on Implant Stability: Biomechanical Evaluation of 2 Different Implant Surfaces in Rabbits

WOS: 000340373100016PubMed: 25051415Objectives: The aim of this study was to evaluate the implant stability with the addition of local application of basic fibroblast growth factor (bFGF) during the osseointegration of 2 different dental implant surfaces using rabbit tibia model. Materials and Methods: Fifty-six dental implants, 28 of hydrophilic surface (SLActive) and 28 of hydrophobic surface (OsseoSpeed), were placed in 14 mature New Zealand rabbits. The rabbits each received both SLActive and OsseoSpeed implants per tibia, and bFGF was applied locally on 1 randomly selected tibia. Half of the subjects were killed at the fourth week of healing period, and the other half were killed at the twelfth week. Stabilization was assessed using resonance frequency analysis (RFA) and removal torque value (RTV). Results: The local application of bFGF was found to enhance osseointegration, especially at the fourth week of healing period after application (P = 0.046). RFAs and RTVs were found to be higher in bFGF-treated implant with hydrophilic surfaces when compared with both bFGF-treated hydrophobic implants and nontreated hydrophilic controls. Conclusion: Local application of bFGF seems to increase the stabilization values in implants with hydrophilic surfaces and those with hydrophobic surfaces