bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of Calcium Hydroxide on pH Changes of the External Medium after Intracoronal Bleaching
Authors: Torres Carlos Rocha Gomes , de Sá Patrícia Marra , Jeronymo Raffaela Di Iorio , Yui Karen Cristina Kazue , da Silva Eduardo Galera , Huhtala Maria Filomena Rocha Lima , Gomes Ana Paula Martins 
Published: November 2011

ABSTRACT

Aim
This in vitro study evaluated the effect of calcium hydroxide on pH changes of the external medium after intracoronal bleaching.

Materials and methods
A total of 50 extracted human premolars were prepared and filled with gutta-percha and endodontic sealer. The teeth were randomly divided into five groups according to the bleaching agents employed: (a) Sterile cotton pellet with distilled water (control group); (b) sodium perborate and distilled water; (c) sodium perborate and 10% carbamide peroxide; (d) sodium perborate and 35% hydrogen peroxide; (e) 35% hydrogen peroxide. The teeth were stored in vials containing distilled water and the pH values of the medium surrounding the teeth were analyzed. After 7-day storage, the bleaching agent was removed and replaced by calcium hydroxide, and the distilled water was changed, in which the teeth were kept stored for further 14 days. Measurement of pH of the external medium (distilled water) was performed 7 days after insertion of the bleaching agents, immediately, 7 and 14 days after insertion of the calcium hydroxide. Data were submitted to statistical analysis by the two-way ANOVA and Tukey, s test.

Results
There were pH changes of the external medium at 7- day period after bleaching procedures. These results confirmed the diffusion of bleaching agents to the external medium.

Conclusion
Calcium hydroxide increased the external medium pH and was effective for pH alkalinization after intracoronal bleaching.

Clinical significance
Intracoronal bleaching of endodontically treated teeth may cause cervical root resorption. A possible explanation for this process is the passage of bleaching agents to the periodontal tissues yielding an inflammatory process. In an attempt to keep the neutrality of the periodontal pH, the calcium hydroxide has been recommended. Results of this study showed that this material should be always used after intracoronal bleaching.

How to cite this article
de Sá PM, Jeronymo RDI, Yui KCK, de Silva EG, Huhtala MFRL, Torres CRG, Gomes APM. Effect of Calcium Hydroxide on pH Changes of the External Medium after Intracoronal Bleaching. J Contemp Dent Pract 2011;12(3): 158-163.
Revisiting Amalgam: A Comparative Study between Bonded Amalgam Restoration and Amalgam Retained with Undercuts
Authors: Gupta Indra , Gupta Satyendra , Kothari Anjali 
Published: November 2011

ABSTRACT

Aim
To compare the retention of amalgam restorations in bonded amalgam restoration and restorations with undercuts.

Background
With improvement in adhesive technology problem associated with conventional preparation for amalgam restorations mainly compromised resistance form of tooth structure have been largely overcome.

Materials and methods
Forty caries free extracted molars were used. A basic box preparation was done proximally with buccoproximal and linguoproximal walls diverging at 45° angle and the axial wall is 1.3 mm in dentin.
Group 1 – Teeth with basic box preparation.
Group 2 – Teeth with box preparation for bonded amalgam.
Group 3 – Teeth with box preparation and proximal retention grooves.
Group 4 – Teeth with box preparation and occlusal dovetail.
Group 1, 3 and 4 were restored with silver amalgam and group 2 restored with resin-bonded amalgam. All samples were subjected to simulated occlusal load against marginal ridge using a blunt stainless steel point in an Instron testing machine. The force in kilogram required to dislodge the restorations as well as the type and location of failure were recorded.

Result
The main force required to dislodge the restoration was least in group 1 and 3 and maximum in group 2.

Conclusion
The in vitro study showed that the amalgam bonding technique, using an adhesive resin liner in proximal box form preparation, was more effective than either box form with proximal grooves or dovetails or proximal box only in providing resistance to displacement.

Clinical significance
Amalgam bonding eliminates the unnecessary removal of sound tooth structure during cavity preparations.

How to cite this article
Gupta I, Gupta S, Kothari A. Revisiting Amalgam: A Comparative Study between Bonded Amalgam Restoration and Amalgam Retained with Undercuts. J Contemp Dent Pract 2011;12(3):164-170.
Thirty Years Clinicopathological Study of 60 Calcifying Cystic Odontogenic Tumors in Iranian Population
Authors: Jafarzadeh Hamid , Habibi Ataollah , Saghravanian Nasrollah , Salehinejad Jahanshah 
Published: November 2011

ABSTRACT

Aim
To reevaluate all cases previously diagnosed as calcifying odontogenic cyst (COC) from the archives of the Department of Oral Pathology at Mashhad Faculty of Dentistry from 1978 to 2008.

Materials and methods
Clinical histories and microscopic slides of all cases diagnosed as COC were reviewed and analyzed statistically. The information about patients such as age, sex, clinical features, radiographic view and other necessary data was gathered from biopsy files.

Results
The majority of cases occurred in mandible and four cases were peripherally. Thirteen cases were associated with other odontogenic tumors and 11 cases were odontoma type. In two cases, recurrence was reported after surgical treatment which underwent malignant transformation.

Conclusion
Calcifying cystic odontogenic tumor (CCOT) in Iranian population occurs in younger age group with slightly male predilection and more mandibular, unicystic and simple type.

Clinical significance
It is better to address the noncystic CCOT lesions with their specific terms in order to make histopathological characteristics clear.

How to cite this article
Habibi A, Saghravanian N, Salehinejad J, Jafarzadeh H. Thirty Years Clinicopathological Study of 60 Calcifying Cystic Odontogenic Tumors in Iranian Population. J Contemp Dent Pract 2011;12(3):171-173.
Unstimulated Whole Saliva Parathyroid Hormone in Postmenopausal Women with Xerostomia
Authors: Mirzaii-Dizgah Iraj , Agha-Hosseini Farzaneh 
Published: November 2011

ABSTRACT

Objective
The aim of this study was to evaluate the correlation of xerostomia severity with unstimulated saliva parathyroid hormone (PTH) and to compare unstimulated whole saliva PTH between postmenopausal women with/without xerostomia.

Methods
A case-control study was carried out in 60 (30 as case and 30 as control) selected postmenopausal women with/ without xerostomia conducted at the Clinic of Oral Medicine, Tehran University of Medical Sciences. Xerostomia inventory (XI) score was also used as an index of xerostomia severity. PTH concentration was analyzed by enzyme-linked immunosorbent assay (ELISA). Statistical analysis of Student's t-test and Spearman correlation was used.

Results
The mean unstimulated saliva PTH concentration was significantly higher but flow rate was lower in the case group compared with control. XI score correlated significantly with saliva PTH (r = 0.688, p = 0.001) and flow rate (r = – 0.529, p = 0.001).

Conclusion
Xerostomia severity correlated positively with unstimulated whole saliva PTH and negatively with saliva flow rate in this group of postmenopausal women. Thus, salivary flow rate and PTH levels appear associated with xerostomia and menopause.

Clinical significance
Salivary PTH level appears to be associated with xerostomia and menopause.

How to cite this article
Agha-Hosseini F, Mirzaii-Dizgah I. Unstimulated Whole Saliva Parathyroid Hormone in Postmenopausal Women with Xerostomia. J Contemp Dent Pract 2011;12(3):196-199.
Chromosomal loss of 3q26.3‐3q26.32, involving a partial neuroligin 1 deletion, identified by genomic microarray in a child with microcephaly, seizure disorder, and severe intellectual disability
Authors: Millson Alison , LaGrave Danielle , Willis Mary J.H. , Rowe Leslie R. , Lyon Elaine , South Sarah T. 
Published: November 2011

AbstractNeuroligin 1 (NLGN1) is one of five members of the neuroligin gene family and may represent a candidate gene for neurological disorders, as members of this family are involved in formation and remodeling of central nervous system synapses. NLGN1 is expressed predominantly in the central nervous system, where it dimerizes and then binds with β‐neurexin to form a functional synapse. Mutations in neurexin 1 (NRXN1) as well as two other members of the neuroligin family, NLGN3 and NLGN4, have been associated with autism and mutations in NLGN4 have also been associated with intellectual disability, seizures, and EEG abnormalities. Genomic microarray is recommended for the detection of chromosomal gains or losses in patients with intellectual disability and multiple congenital anomalies. Results of uncertain significance are not uncommon. Parental studies can provide additional information by demonstrating that the imbalance is either de novo or inherited, and therefore is more or less likely to be causative of the clinical phenotype. However, the possibility that even inherited deletions and duplications may play a role in the phenotype of the proband cannot be excluded as many copy number variants associated with neurodevelopmental conditions show incomplete penetrance and may be inherited from an unaffected parent. Here, we report on a patient with a 2.2 Mb deletion at 3q26.3‐3q26.32—encompassing the terminal end of NLGN1 and the entire NAALADL2 gene—detected by genomic microarray, and confirmed by FISH and real‐time quantitative PCR. The same size deletion was subsequently found in her healthy, asymptomatic, adult mother. © 2011 Wiley Periodicals, Inc.
Microtia: Epidemiology and genetics
Authors: Luquetti Daniela V. , Heike Carrie L. , Hing Anne V. , Cunningham Michael L. , Cox Timothy C. 
Published: November 2011

AbstractMicrotia is a congenital anomaly of the ear that ranges in severity from mild structural abnormalities to complete absence of the ear, and can occur as an isolated birth defect or as part of a spectrum of anomalies or a syndrome. Microtia is often associated with hearing loss and patients typically require treatment for hearing impairment and surgical ear reconstruction. The reported prevalence varies among regions, from 0.83 to 17.4 per 10,000 births, and the prevalence is considered to be higher in Hispanics, Asians, Native Americans, and Andeans. The etiology of microtia and the cause of this wide variability in prevalence are poorly understood. Strong evidence supports the role of environmental and genetic causes for microtia. Although some studies have identified candidate genetic variants for microtia, no causal genetic mutation has been confirmed. The application of novel strategies in developmental biology and genetics has facilitated elucidation of mechanisms controlling craniofacial development. In this paper we review current knowledge of the epidemiology and genetics of microtia, including potential candidate genes supported by evidence from human syndromes and animal models. We also discuss the possible etiopathogenesis in light of the hypotheses formulated to date: Neural crest cells disturbance, vascular disruption, and altitude. © 2011 Wiley Periodicals, Inc.
Characteristics of the photochemical prevulcanization in a falling film photoreactor
Authors: Schlögl Sandra , Temel Armin , Schaller Raimund , Holzner Armin , Kern Wolfgang 
Published: November 2011

AbstractThe photochemical prevulcanization of natural rubber (NR) latex via the thiol‐ene reaction is a new approach aiming at the replacement of noxious processing agents used in conventional sulfur vulcanization processes (e.g., accelerators) together with cost saving options. The crosslinking reaction involves the excitation of a selected photoinitiator with ultraviolet (UV) light which is followed by the formation of thioether links due to the thiol‐ene addition reaction. The photochemical process is carried out in a falling film photoreactor which provides not only a continuous prevulcanization process but also exhibits a technology which is already commercially well established. The main advantage of the falling film process lies in the short prevulcanization time and the mild reaction temperature. Following the idea of the manufacture of low‐allergenic surgical gloves made from NR latex without compromising on the glove quality by means of physical performance, crucial process parameters of the falling film process have been determined and characterized in this study. Surgical gloves were made from the photocured NR latex which was prevulcanized using selected process conditions. The physical properties including tensile strength, elongation, modulus, and crosslink density were examined together with the aging stability and the stability against high‐energy radiation (sterilization with gamma rays). It was found that the UV light intensity, the number of illumination cycles, the choice of photoinitiator, and the thiol crosslinker play an important part in the glove quality. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
An improved sample preparation method for monomer conversion measurement using headspace gas chromatography in emulsion polymerization research
Authors: Zhong Jin‐Feng , Chai Xin‐Sheng , Fu Shi‐Yu , Qin Xiao‐Li 
Published: November 2011

AbstractThis article reports an improved headspace gas chromatographic (HS‐GC) technique for the determination of monomers in polymer latex. The method is based on a HS‐GC technique reported previously (Chai et al., J Appl Polym Sci 2006, 99, 392) but includes a major modification in the method of sample preparation. By using a weight‐based sampling method, coupled with initial dissolution in dimethyl sulfoxide (DMSO), followed by water dilution, the uncertainty in the sample preparation associated with previous method can be significantly reduced. The improved method is reliable, practical, and suitable for use in the kinetic study during emulsion polymerization. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
State Variable Approach for the Structural Analysis of Hormonal Controlled Long Term Blood Pressure Regulatory System
Authors: Shahin M. , Maka S. 
Published: November 2011

AbstractLong term arterial blood pressure regulation involves complex interactions of the cardiovascular system, kidney and other organs. In hypertension related diseases, the control pathways are impaired and parameters for its quantification might be of prognostic importance. In this paper, we introduce methods based on the state variable approach for the enhanced analysis of complex interactions. To assess the dynamics of arterial blood pressure regulation, the linearized state model has been employed. This paper presents a seventh order nonlinear mathematical model of the long term arterial blood pressure regulation incorporating many of the nervous control mechanisms and hormonal activities. Subsequently, the structural properties, as well as the transient and steady state properties, are assessed using the eigen value concept. The comparison of model response with those of the nonlinear model shows close matching. In conclusion, the analysis of the linearised model provides insights into complex, nonlinear physiological interactions and furthermore reveals physiological cardiovascular control about the equilibrium point.
Combinatorial insulin secretion dynamics of recombinant hepatic and enteroendocrine cells
Authors: Durvasula Kiranmai , Thulé Peter M. , Sambanis Athanassios 
Published: November 2011

AbstractOne of the most promising cell‐based therapies for combating insulin‐dependent diabetes entails the use of genetically engineered non‐β cells that secrete insulin in response to physiologic stimuli. A normal pancreatic β cell secretes insulin in a biphasic manner in response to glucose. The first phase is characterized by a transient stimulation of insulin to rapidly lower the blood glucose levels, which is followed by a second phase of insulin secretion to sustain the lowered blood glucose levels over a longer period of time. Previous studies have demonstrated hepatic and enteroendocrine cells to be appropriate hosts for recombinant insulin expression. Due to different insulin secretion kinetics from these cells, we hypothesized that a combination of the two cell types would mimic the biphasic insulin secretion of normal β cells with higher fidelity than either cell type alone. In this study, insulin secretion experiments were conducted with two hepatic cell lines (HepG2 and H4IIE) transduced with 1 of 3 adenoviruses expressing the insulin transgene and with a stably transfected recombinant intestinal cell line (GLUTag‐INS). Insulin secretion was stimulated by exposing the cells to glucose only (hepatic cells), meat hydrolysate only (GLUTag‐INS), or to a cocktail of the two secretagogues. It was found experimentally that the recombinant hepatic cells secreted insulin in a more sustained manner, whereas the recombinant intestinal cell line exhibited rapid insulin secretion kinetics upon stimulation. The insulin secretion profiles were computationally combined at different cell ratios to arrive at the combinatorial kinetics. Results indicate that combinations of these two cell types allow for tuning the first and second phase of insulin secretion better than either cell type alone. This work provides the basic framework in understanding the secretion kinetics of the combined system and advances it towards preclinical studies. Biotechnol. Bioeng. 2012; 109:1074–1082. © 2011 Wiley Periodicals, Inc.
Application of hollow fiber‐supported liquid‐phase microextraction coupled with HPLC for the determination of guaifenesin enantiomer–protein binding
Authors: Hatami Mehdi , Farhadi Khalil 
Published: November 2011

ABSTRACTA hollow fiber liquid‐phase microextraction technique coupled with high‐performance liquid chromatography with fluorescence detection was employed for determination and evaluation of the binding characteristics of drugs to bovine serum albumin (BSA). Enantiomers of guaifenesin (an expectorant drug) were investigated as a model system. After optimization of some influencing parameters on microextraction, the proposed method was used for calculation of the target drug distribution coefficient between n‐octanol and the buffer solution as well as study of drug–BSA binding in physiological conditions. The developed method shows a new, improved and simple procedure for determination of free drug concentration in biological fluids and the extent of drug–protein binding. Copyright © 2011 John Wiley & Sons, Ltd.
Transcatheter aortic valve implantation with a self‐expanding nitinol bioprosthesis
Authors: Saia Francesco , Lemos Pedro A. , Bordoni Barbara , Cervi Elena , Boriani Giuseppe , Ciuca Cristina , Taglieri Nevio , Mariani Jose , Filho Roberto Kalil , Marzocchi Antonio 
Published: November 2011

AbstractObjective: To ascertain incidence and predictors of new permanent pacemaker (PPM) following transcatheter aortic valve implantation (TAVI) with the self‐expanding aortic bioprosthesis. Background: TAVI with the Medtronic Corevalve (MCV) Revalving System (Medtronic, Minneapolis, MN) has been associated with important post‐procedural conduction abnormalities and frequent need for PPM. Methods: Overall, 73 consecutive patients with severe symptomatic AS underwent TAVI with the MCV at two institutions; 10 patients with previous pacemaker and 3 patients with previous aortic valve replacement were excluded for this analysis. Clinical, echocardiographic, and procedural data were collected prospectively in a dedicated database. A standard 12‐lead ECG was recorded in all patients at baseline, after the procedure and predischarge. Decision to implant PPM was taken according to current guidelines. Logistic multivariable modeling was applied to identify independent predictors of PPM at discharge. Results: Patients exhibited high‐risk features as evidenced by advanced age (mean = 82.1 ± 6.2 years) and high surgical scores (logistic EuroSCORE 23.0 ± 12.8%, STS score 9.4 ± 6.9%). The incidence of new PPM was 28.3%. Interventricular septum thickness and logistic Euroscore were the baseline independent predictors of PPM. When procedural variables were included, the independent predictors of PPM were interventricular septum thickness (OR 0.52; 95% CI 0.32–0.85) and the distance between noncoronary cusp and the distal edge of the prosthesis (OR 1.37; 95% CI 1.03–1.83). Conclusions: Conduction abnormalities are frequently observed after TAVI with self‐expandable bioprosthesis and definitive pacing is required in about a third of the patients, with a clear association with depth of implant and small interventricular septum thickness. © 2011 Wiley Periodicals, Inc.
Organogel–Hydrogel Transformation by Simple Removal or Inclusion of N‐Boc‐Protection
Authors: Kar Tanmoy , Mandal Subhra Kanti , Das Prasanta Kumar 
Published: November 2011

AbstractDevelopment of organo‐ and hydrogelators is on the rise because of their extensive applications, from advanced materials to biomedicine. However, designing both types of gelator from a common structural scaffold is challenging, and becomes more significant if transformation between them can be achieved by a simple method. The present work reports the design and synthesis of both organo‐ and hydrogelators from amino acid/peptide‐based amphiphilic precursors with a naphthyl group at the N terminus and a primary amine‐containing hydrophilic ethyleneoxy unit at the C terminus. In alkaline medium, tert‐butyloxycarbonyl (Boc) protection at the primary amine of the amphiphiles resulted in efficient organogelators (minimum‐gelation concentration (MGC)=0.075–1.5 % w/v). Interestingly, removal of the Boc protection from the ethyleneoxy unit, under acidic conditions, yielded amphiphiles capable of gelating water (MGC=0.9–3.0 % w/v). Simple protection and deprotection chemistry was used to achieve transformation between the organogel and hydrogel by alteration of the pH. Combinations of different aliphatic and aromatic amino acids were investigated to discover their cumulative effect on the gelation properties. Field‐emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) were employed to investigate the supramolecular morphology of the thermoreversible gels. Spectroscopic investigations (FTIR, photoluminescence, XRD) revealed that noncovalent interactions, such as hydrogen bonding, π–π stacking, and van der Waals interactions play a decisive role in self‐assembled gelation.
Exploring photochemistry of 2‐(phenylazo)pyridine dye by using TDDFT/DFT methods
Authors: Tongying Pornthip , Yoopensuk Suthirat , Leesakul Nararak , Tantirungrotechai Yuthana 
Published: November 2011

AbstractThe non‐emissive behaviour of 2‐(phenylazo)pyridine, azpy, observed in the fluorescence experiment was explained by investigating its photoisomerisation mechanism. By using the Density Functional Theory and Time‐dependent Density Functional Theory (DFT/TDDFT) methods, the two‐dimensional potential energy surfaces in the ground state, and the first and second excited states which are relevant to the trans‐to‐cis isomerisation were constructed. The pathways related to the inversion, rotation and their concerted motion of the phenyl and pyridyl groups around NN bond were considered. The energy profiles depend not only on the type of pathways but also on the moving group. The concerted‐inversion pathways show the possibility of S1/S2 and S0/S1 conical intersections. The relaxation through such intersections should increase the non‐radiative transition rate to the extent that the compound does not emit fluorescence. © 2011 Canadian Society for Chemical Engineering