Search results for "pulp"
showing 10 items of 717 documents
Dentin-pulp complex reactions in conventional and radiation-related caries: A comparative study
2019
Background Radiation-related caries (RRC) is one of the most significant oral toxicities of head and neck radiotherapy (HNRT); however, the potential of radiation to directly cause harmful dentin and pulpal effects and impair response to caries progression is controversial. Material and Methods Therefore, the aim of this study was to characterize the reactions of the dentin-pulp complex in teeth affected by RRC. Patients and methods: Twenty-two carious teeth extracted from 22 head and neck cancer (HNC) patients were divided into control (conventional caries; n=11) and irradiated (RRC; n=11) groups and paired matched by dental homology, clinical patterns of caries progression following the P…
Aroma transfers in and through plastic packagings: orange juice andd-limonene. A review. Part I: Orange juice aroma sorption
1997
Orange juice and one of its major volatile constituents, d-limonene, were probably amongst the first food products to be thoroughly studied. Yet, no extensive literature review has been undertaken in order to obtain a general and accurate description of the sorption and diffusion phenomena. This review underlines the effects of packaging on the organoleptic quality of citrus juices; it therefore presents a focused interest on d-limonene mass transfer experimental results with a variety of plastic polymers. Part I deals with first, loss of organoleptic quality of orange juice during storage and d-limonene sorption is discussed. Second, generalites are presented concerning volatiles transfer …
The Finnish pulp and paper industry: a case study in media as stakeholder
1998
Presents and analyses a current discourse surrounding social and environmental responsibility in the Finnish paper industry between 1970–1995. Addresses theoretical modes of social responsibility and related environmental issues. Media as forum for debate and discourse are described and the campaign to protect Finnish wild forestry is discussed. Implications for strategic communication theory and practice are considered.
Radiographic Investigation of Frequency and Location of Root Canal Curvatures in Human Mandibular Anterior Incisors In Vitro
2007
The aim of the present in vitro study was to evaluate the degree and location of root canal curvatures of mandibular anterior incisors. A total of 396 extracted human permanent anterior incisors (248 central and 148 lateral) were included in this investigation. Exclusion criteria were teeth with extensive carious lesions, restorations, and root canal treatment. The specimens were fixed in a special device and digitally x-rayed (Heliodent MD; Sirona, Benzheim, Germany; Merlin 2.1, Olympus/PerkinElmer, Waltham, MA) with the parallel technique. The distances from the cementoenamel junction (CEJ) to the first curvatures as well as the according angles were recorded. The results were analyzed de…
A smart rotary technique versus conventional pulpectomy for primary teeth: A randomized controlled clinical study.
2017
Background Techniques with adequate accuracy of working length determination along with shorter duration of treatment in pulpectomy procedure seems to be essential in pediatric dentistry. The aim of the present study was to evaluate the accuracy of root canal length measurement with Root ZX II apex locator and rotary system in pulpectomy of primary teeth. Material and methods In this randomized control clinical trial complete pulpectomy was performed on 80 mandibular primary molars in 80, 4-6-year-old children. The study population was randomly divided into case and control groups. In control group conventional pulpectomy was performed and in the case group working length was determined by …
Three canals in the mesial root of mandibular first permanent molars: a clinical study
1989
Traditional teaching of the anatomy of root canals in different teeth can lead clinicians into the misguided belief that a predetermined number of root canals is always present in any given tooth. A new understanding of the root canal system has enabled the location of additional canals. Results of the clinical study of 760 first mandibular molars, showed that 20 (2.6 per cent) had three canals in the mesial root. Of these 20 teeth, 13 (65 per cent) had an intermediate canal which joined the mesiobuccal canal in the apical third. In six cases (30 per cent) it joined the mesiolingual canal in the same area. In only one case did the intermediate or third canal retain its individual nature and…
Radiographic Investigation of Location and Angulation of Curvatures in Human Maxillary Incisors
2008
The aim of this radiographic study was to evaluate the degree and location of root canal curvatures of human maxillary incisors. A total of 286 extracted human maxillary incisors (145 central and 141 lateral incisors) were included in this investigation. Exclusion criteria were teeth with extensive carious lesions, restorations, and root canal treatment. For this in vitro study, the teeth were fixed in a special device and digitally x-rayed with the parallel technique. The distances from the cementoenamel junction (CEJ) to the first curvature and the according angle were recorded. The results were analyzed descriptively, and p values were calculated with the Wilcoxon Mann-Whitney test. The …
In vitro comparison of root-canal measurements with conventional and digital radiology.
2002
Aim The present study compared the efficacy of digital and conventional radiology for root-canal length measurement. Methodology Seventy extracted teeth with pre-served roots were used. Root-canal length measurements were completed with K-Flexofiles (numbers 08, 10 and 15) with conventional and digital radiography using two systems (radiovisiography and photostimulate storage phosphor). All films and sensors were exposed at projections of 0 degrees and 20 degrees to the mesial. The images obtained were evaluated with and without magnification, and analysed using the Cohen's kappa test. The accuracy of the three systems to determine the root-canal length were evaluated by measuring the dista…
Canal shaping with a reciprocating system is easy to learn.
2018
To assess progressive learning of root canal shaping in order to define the number of simulated canals in resin blocks needed to reach a level of learning beyond which no further improvement in performance is observed.A total of 216 simulated canals in resin blocks were instrumented by 18 operators without experience in Endodontics and by 18 Endodontists. The R25 file of the Reciproc system (VDW, Munich, Germany) was used to prepare the canals. The blocks were photographed before and after instrumentation. An analysis was made of the variations in the dimensions of the canals at 6 locations and of the instrumentation time. A Student's t-test was used to analyse the data (P 0.05).The group …
Development of a Higee bioreactor (HBR) for production of polyhydroxyalkanoate: Hydrodynamics, gas–liquid mass transfer and fermentation studies
2010
Abstract This study addresses the hydrodynamics and mass transfer characterisation of a Higee bioreactor (HBR) for application to polyhydroxyalkanoate (PHA) production from Pseudomonas putida KT2442 fermentation. The motivation for this work is to address the potential oxygen transfer limitations which can severely impede the progress of this aerobic fermentation process and reduce PHA productivity in conventional bioreactors. It is shown that a maximum of 2.5 transfer units can be achieved in an oxygen-stripping operation where the presence of packing, higher rotor speeds, higher air flowrates and lower liquid flowrates all have a positive influence on the number of transfer units (NTU). W…