bluuebunny/crossref_metadata_2025_split huggingface dataset:
Accuracy of a new apex locator: an in vitro study
Authors: Kaufman A. Y. , Keila S. , Yoshpe M. 
Published: March 2003

AbstractAim The purpose of this study was to test in an in vitro model the accuracy of a Bingo 1020 electronic apex locator, to compare the results to those of a well known apex locator, Root ZX, as well as to those of the radiographic method of tooth length determination.Methodology A total of 120 extracted teeth, preserved in Thymol solution and kept refrigerated, was used for the study. The experiment was performed on single‐rooted teeth and on one‐root canal, chosen randomly, in multirooted teeth. The teeth were randomly divided into 12 groups of 10 teeth each. After access preparation, the actual length (AL) was measured. The teeth were embedded in an alginate model specially developed for testing apex locators. Electronic tooth length measurements (EL) were carried out prior to root canal preparation using the two electronic apex locators (EAL) – Root ZX and Bingo 1020; three measurements were taken and an average computed. After the third measurement, the file was left in the root canal and a periapical radiograph was taken. The radiographic length (RL) was recorded by measuring the file length from the coronal reference point to the tip of the file. Each root canal was then prepared to a no. 40 K‐file diameter using a standardized technique; saline was used for irrigation. Upon completion of the root canal preparation, EL measurements were taken by each EAL in dry conditions and with different irrigation solutions. Each measurement was repeated three times. The RL was recorded according to the last EL measurement. Results were subjected to statistical analysis.Results In all parameters tested, a significant statistical difference was found between Bingo 1020 and the Root ZX. Measurements obtained using the Bingo 1020 were consistently closer to the AL (0.08 mm) than those obtained using the Root ZX. Both EALs measured the tooth length with great accuracy and a positive correlation of 0.76 (P = 0.00) existed between the two devices. No significant difference was found between the two apex locators when measurements were taken with the different irrigants (P = 0.34) and the content of the root canal did not affect the accuracy of the measurements. Lengths obtained by calculations from the radiographs were longer than the AL as well as the length obtained by both EALs (P = 0.00).Conclusions The Bingo 1020 proved to be as reliable as Root ZX and was user friendly. Under the experimental conditions, electronic measurements were more reliable than radiographs in the process of root length determination.
An in vitro comparison of pH changes in root dentine following canal dressing with calcium hydroxide points and a conventional calcium hydroxide paste
Authors: Ardeshna S. M. , Qualtrough A. J. E. , Worthington H. V. 
Published: March 2003

AbstractAim This study aimed to measure and compare pH changes at apical and cervical sites on the external root surface of extracted teeth dressed with calcium hydroxide in two different formulations.Methodology Root canals of 45 single‐rooted extracted human teeth were accessed and shaped using a step‐down technique with rotary instrumentation. Standard cavities were prepared on the external root surface at specific apical and cervical sites. The teeth were randomly allocated to three groups. Teeth in group A were dressed with calcium hydroxide points, those in group B were dressed with an aqueous calcium hydroxide paste and teeth in group C were left unfilled. Following storage in humid conditions, the pH of the dentine at apical and cervical sites was measured at baseline and then at 24 h, 72 h, 1 week, 10 days, 2 weeks and 3 weeks.Results The pH of the root dentine at both apical and cervical sites was significantly greater (P < 0.001) in teeth dressed with aqueous calcium hydroxide paste compared with those dressed with calcium hydroxide points, when averaged out across all time periods. For all groups, there was a significant difference between the mean apical and cervical pH values for each tooth with lower values for the apical sites (P < 0.001).Conclusion The results of this study indicate that an aqueous calcium hydroxide paste was more effective than calcium hydroxide points at raising the pH on the external root surface of extracted teeth.
A protocol for polymerase chain reaction detection of Enterococcus faecalis and Enterococcus faecium from the root canal
Authors: Molander A. , Lundquist P. , Papapanou P. N. , Dahlén G. , Reit C. 
Published: March 2003

AbstractAim The present study was set up to develop a protocol for detection of Enterococcus faecalis and Enterococcus faecium from the root canal.Methodology A collection of type strains and clinical isolates of E. faecalis and E. faecium was used. Specific polymerase chain reaction (PCR) primers targeted against the 16S/23S rDNA intergenic region were used and PCR reactions were set up. PCR products were run on TBE‐agarose gel and analysed. The sensitivity of the PCR system was studied using serial dilutions of (i) bacterial DNA and (ii) bacterial cells from E. faecalis. The specificity of the identification was tested against closely related species.Results All strains of E. faecalis and E. faecium produced identical amplicon profiles composed of two major bands corresponding to sizes of 320 and 420 bp. When amplifying DNA of higher purity, a third band of 600 bp became evident as well. Closely related species demonstrated single bands of various sizes and were easily distinguished from enterococci. The detection level of DNA from serial dilutions of DNA was 10−13 g. The DNA extraction protocol from bacterial cell suspensions resulted in a detection level of 10 bacterial cells per sample.Conclusions The present study demonstrated a good potential for using PCR technology in the detection of E. faecalis and E. faecium from root canal samples. With a high specificity the methodology was able to detect 10 cells of E. faecalis.
An in vitro comparison of the bactericidal efficacy of lethal photosensitization or sodium hyphochlorite irrigation on Streptococcus intermedius biofilms in root canals
Authors: Seal G. J. , Ng Y.‐L. , Spratt D. , Bhatti M. , Gulabivala K. 
Published: March 2003

AbstractAim To compare the bacterial killing of Streptococcus intermedius biofilms in root canals using lethal photosensitization with various combinations of photosensitizer concentration and laser light dose or 3% sodium hypochlorite (NaOCl) irrigation.Methodology Extracted teeth (n = 35) with single canals were selected and the canals prepared to apical size 25 with a 10% taper. The teeth were autoclaved and the canals inoculated with Streptococcus intermedius in brain heart infusion broth and were incubated for 48 h to allow a biofilm to form. The teeth were then subjected to 3% NaOCl irrigation (n = 4) or lethal photosensitization using combinations of a range of toluidine blue O (TBO) photosensitizer concentrations (12.5, 25, 50, 100 µgmL−1) and light doses (60, 90, 120, 300, 600 s equivalent to energy doses of 2.1–21 J) using a 35‐mW helium–neon low power laser targeted at the access cavity (n = 4 for each combination). Controls consisted of laser light only (TBO = 0 µgmL−1) (n = 4), TBO only (light dose = 0 s) (n = 4), and no treatment (positive control n = 17). Following treatment the canal contents were sampled with sterile paper points, the sample was dispersed in transport medium, serially diluted and cultured on blood agar to determine the number of colony forming units (CFU).Results The combination of 100 µgmL−1 TBO and 600 s (21 J) of laser energy achieved maximum reduction in recovered viable bacteria (5 log10 CFU). TBO at low concentrations (≤50 µgmL−1) was not bactericidal but treatment with 100 µgmL−1 TBO alone reduced recovered viable bacteria by 3 log10 CFU. Laser light alone had limited bactericidal effect. No viable bacteria were recovered following treatment with 3% NaOCl.Conclusions The combined use of a photosensitizing agent and a low power laser directed at the access cavity was bactericidal to S. intermedius biofilms in root canals but was unable to achieve total kill, unlike 3% NaOCl.
The perceived benefit of endodontic retreatment
Authors: Kvist T. , Reit C. 
Published: March 2003

AbstractKvist T, Reit C. The perceived benefit of endodontic retreatment. International Endodontic Journal, 35, 359–365, 2002.Aim There is substantial variation amongst dentists in the management of symptom‐free periapical lesions in root‐filled teeth. It has been suggested that this variation can be understood as clinicians’ choice of different cut‐off points on a continuous periapical health scale (the ‘Praxis Concept (PC) theory’). Based on this suggestion, an individual’s inclination to propose retreatment can be expressed in the Retreatment Preference Score (RPS). In the present study it was hypothesized that: (i) the PC theory is valid amongst experienced endodontists; and that (ii) interindividual variation in RPS can be explained by a corresponding variation in the perceived benefit of endodontic retreatment.Methodology The RPS was determined for 16 experienced Swedish endodontists. The retreatment benefit (RTB) was defined as the gain in utility when a root‐filled tooth with a persistent periapical lesion (‘health state B’) moved to a state where the lesion had healed (‘health state A’). For each individual the utility values of the two health states were measured by means of the standard gamble technique.Results The RPS and RTB were found to be subjected to substantial inter‐ and intrarater variation. The decision makers acted in accordance with the PC theory. No significant correlation between RPS and RTB was detected.Conclusions Findings suggest that the PC theory is valid amongst endodontic experts. The study did not support the notion that the more potential utility that could be produced, the more the individual dentist should tend to perform retreatment. However, alternative consequentialist strategies focusing low risk taking may be involved.
Reduction in intracanal bacteria during root canal preparation with and without apical enlargement
Authors: Coldero L. G. , McHugh S. , MacKenzie D. , Saunders W. P. 
Published: March 2003

AbstractAim To compare in vitro intracanal bacterial reduction using nickel–titanium rotary instruments with and without apical enlargement.Methodology Thirty‐eight palatal roots of maxillary molar teeth, with mature apices were subdivided according to lengths and then randomly assigned to two experimental and one control groups. The roots were sterilized and then reinfected with Enterococcus faecalis, which served as a bacteriological marker. All roots in the experimental groups were prepared in a step‐down sequence with engine‐driven GT rotary files at 350 rpm. In experimental group A (n = 16) additional apical enlargement to ISO size 35 was performed. In group B (n = 16) a serial step‐back technique was followed with no apical enlargement. This was combined in groups A and B with irrigation with NaOCl and EDTA. In the control group (group C, n= 6) irrigation only was carried out, with no mechanical preparation. Samples were then taken from the root canals to determine the numbers of remaining bacteria.Results In groups A and B, 15 (94%) and 13 (81%) specimens were rendered bacteria‐free, respectively. In the control group C none of the specimens were bacteria‐free. There was a significant difference (P < 0.001) in the antibacterial effects of experimental and control regimens. There was, however, no significant difference (P = 0.276) between the preparation methods used in the experimental groups.Conclusions There was no significant difference in intracanal bacterial reduction when Ni–Ti GT rotary preparation with NaOCl and EDTA irrigation was used with or without apical enlargement preparation technique. It may therefore not be necessary to remove dentine in the apical part of the root canal when a suitable coronal taper is achieved to allow satisfactory irrigation of the root canal system with antimicrobial agents.
Supplementary routes to local anaesthesia
Authors: Meechan J. G. 
Published: March 2003

Abstract Meechan JG. Supplementary routes to local anaesthesia. International Endodontic Journal, 35, 885–896, 2002.The satisfactory provision of many dental treatments, particularly endodontics, relies on achieving excellent pain control. Unfortunately, the administration of a local anaesthetic solution does not always produce satisfactory anaesthesia of the dental pulp. This may be distressing for both patient and operator. Fortunately, failure of local anaesthetic injections can be overcome. This is often achieved by using alternative routes of approach for subsequent injections. Nerves such as the inferior alveolar nerve can be anaesthetized by a variety of block methods. However, techniques of anaesthesia other than the standard infiltration and regional block injections may be employed successfully when these former methods have failed to produce adequate pain control. This paper describes some supplementary local anaesthetic techniques that may be used to achieve pulpal anaesthesia for endodontic procedures when conventional approaches have failed. Although some of these techniques can be used as the primary form of anaesthesia, these are normally employed as ‘back‐up’. The methods described are intraligamentary (periodontal ligament) injections, intraosseous anaesthesia and the intrapulpal approach. The factors that influence the success of these methods and the advantages and disadvantages of each technique are discussed. The advent of new instrumentation, which permits the slow delivery of local anaesthetic solution has led to the development of novel methods of anaesthesia in dentistry. These new approaches are discussed.
Testosterone replacement therapy in older adult men
Authors: Tenover J. Lisa 
Published: March 2003

Serum testosterone levels decline slowly with normal ageing in men and, although all men are not destined to become hypogonadal as they age, the prevalence of androgen deficiency in the older male is not insignificant. Over the past several decades, there has been an increasing interest in evaluating whether testosterone therapy (male HRT) might be beneficial for certain older men in preventing or reversing some aspects of ageing. The major androgen target organs of interest with regard to beneficial effects of male HRT include bone, muscle, adipose tissue, the cardiovascular system and the central nervous system (libido and aspects of mood). At the same time, potential adverse effects of male HRT on target organs such as the prostate continue to be evaluated. It is the purpose of this review to summarize the information to date with regard to testosterone replacement therapy in the older man and to discuss areas where more research and clinical information need to be forthcoming.Hormonal replacement therapy (HRT) for post‐menopausal women has been studied and discussed for many years. The idea of male HRT, however, is a relatively recent development, with increasing interest in this area occurring only over the past two decades. Reasons for this nascent enthusiasm include burgeoning evidence that testosterone levels decline with normal male ageing (and with age‐associated diseases) and an interest in preventing age‐related dysfunction and prolonging quality life among an ever increasing population of older adults. The decline in testosterone with age often parallels unfavourable changes in organs upon which androgens act and the goal of male HRT would be to prevent, stabilize or even reverse some of these detrimental target‐organ changes.
Inter‐observer variation in the results of the clinical andrological examination including estimation of testicular size
Authors: Carlsen Elisabeth , Andersen Anne‐Grethe , Buchreitz Louise , JØrgensen Niels , Magnus Øystein , Matulevicuus Valentinas , Nermoen Ingrid , Petersen JØrgen Holm , Punab Margus , Suominen Jyrki , Zilaitiene Birute , Giwercman Aleksander 
Published: March 2003

Inter‐observer variation in andrological examination by 10 clinical investigators from five Nordic and Baltic countries was investigated. In addition, information on intra‐observer variation was obtained for six of the 10 investigators. Testicular size was measured using Prader’s orchidometer and one of the investigators also performed an ultrasound estimate of testicular size. A highly significant difference (p < 0.001) between observers was found with an inter‐observer error of 16% in estimating testicular size in 23 young men. The difference in the estimate tended to increase with increasing testicular size. There was no significant intra‐observer difference in two measurements performed on consecutive days. Only differences in median testis size, which were greater than 31% between measurements by two investigators, were found to be significant at the 5% level. The ultrasound estimate of testicular size was significantly lower than the orchidometer estimate, with a mean difference of 3.6 mL for the left testis and 4.3 mL for the right testis. Tanner staging of genitalia and diagnosis of a varicocele was subject to great inter‐observer variation, and for the diagnosis of varicocele only one‐third of the investigators was able to reproduce their results on a second examination.In conclusion, it was found that the clinical andrological examination of young men is subject to great inter‐observer variation. This should be kept in mind when results from different studies are compared as well as in daily clinical practice.
Seminal plasma androgen/oestrogen balance in infertile men
Authors: LUBOSHITZKY R. , KAPLAN‐ZVERLING M. , SHEN‐ORR Z. , NAVE R. , HERER P. 
Published: March 2003

SummaryThe hypothesis that the balance between oestrogen and androgen in seminal plasma is important for normal fertility was investigated. We determined the concentrations of oestradiol and testosterone in blood and seminal plasma from 62 infertile men and 32 normozoospermic men. Infertile men were classified according to semen analysis (concentration, motility and morphology): asthenozoospermia, oligozoospermia and oligoteratoasthenozoospermia. Serum luteinizing hormone (LH) and follicle‐stimulating hormone (FSH) were determined in all participants. For all subjects, mean testosterone levels were lower and mean oestradiol were higher in seminal plasma than in blood. Seminal plasma testosterone levels were lower in the infertile groups vs. control men ( p < 0.0002). Oligpzoospermic and oligoteratoasthenozoospermic men had significantly higher seminal plasma oestradiol levels compared with controls ( p < 0.03). The three infertile groups had significantly lower seminal plasma testosterone/oestradiol ratio than control men ( p < 0.001). Sperm analysis data (concentration, motility and morphology) significantly correlated with seminal plasma testosterone/oestradiol ratio. The findings of elevated seminal plasma oestradiol, decreased testosterone and testosterone/oestradiol ratio in infertile men, and the significant correlation between hormone levels and sperm analysis data suggest that the local balance between androgen and oestrogen is important for spermatogenesis.
Quantitative analysis of the development of experimentally induced post surgical adhesions: a microstereological study
Authors: Ricketts Sally‐Ann , Sibbons Paul D. , Green Colin J. 
Published: March 2003

The aim of this study was to quantitatively define the development of post surgical adhesions (PSAs) in a well characterized experimental model and identify possible windows of pathogenesis where pharmaceutical intervention may be most effective.PSAs were induced, in an established rabbit uterine horn model, using standardized reproducible injury, in 17 experimental groups, each with 8 experimental sites and these PSAs were sampled from 30 seconds to 42 days post surgery. Using design based, unbiased stereology, mean volumes of PSAs and associated tissue damage and reaction per experimental site were calculated for each sample time point.PSA development followed the normal pattern of wound healing with surrounding adjacent tissue having a profound influence and interaction. There was a direct relationship between volume of damage (initial and subsequent) and the volume of injury tissue generated. In vivo weak fibrinous PSAs were present from 10 min following injury, with tenacious fibrinous PSAs present from 1 h and onwards. PSA development can be classified into two distinct stages: (i) PSA modelling — occurring during the first 16 h, in which maximum rate of PSA construction is achieved; and (ii) PSA remodelling — from 16 h onwards. Considering this, PSA prevention should ideally be initiated immediately post injury to prevent PSA modelling or, alternatively, during PSA modelling.
The biology of the combretastatins as tumour vascular targeting agents
Authors: TOZER GILLIAN M. , KANTHOU CHRYSO , PARKINS CHARLES S. , HILL SALLY A. 
Published: March 2003

SummaryThe tumour vasculature is an attractive target for therapy. Combretastatin A‐4 (CA‐4) and A‐1 (CA‐1) are tubulin binding agents, structurally related to colchicine, which induce vascular‐mediated tumour necrosis in animal models. CA‐1 and CA‐4 were isolated from the African bush willow, Combretum caffrum, and several synthetic analogues are also now available, such as the Aventis Pharma compound, AVE8062. More soluble, phosphated, forms of CA‐4 (CA‐4‐P) and CA‐1 (CA‐1‐P) are commonly used for in vitro and in vivo studies. These are cleaved to the natural forms by endogenous phosphatases and are taken up into cells. The lead compound, CA‐4‐P, is currently in clinical trial as a tumour vascular targeting agent. In animal models, CA‐4‐P causes a prolonged and extensive shut‐down of blood flow in established tumour blood vessels, with much less effect in normal tissues. This paper reviews the current understanding of the mechanism of action of the combretastatins and their therapeutic potential.
Some factors affecting Norway lobster (Nephrops norvegicus) cuticle polyphenol oxidase activity and blackspot development
Authors: Bartolo Ivan , Birk Else O. 
Published: March 2003

SummaryPolyphenol oxidase (PPO) activity was measured in the cuticles of Norway lobsters caught over a period of 7 months. Increased PPO activity was observed between early August and early October 1995, coinciding with one of the reported annual periods of peak moulting activity, although a high PPO activity detected in May may have marked the spring moulting period. A relationship was found between the number of claws remaining on the Norway lobsters and the PPO activity, suggesting that exposing Norway lobsters to damage and stress is associated with an increase in PPO activity. No correlation was observed between initial PPO activity and blackspot development during storage of the Norway lobsters. This indicates that biochemical events occurring during storage are more important to blackspot development than the initial PPO level.
Verification of a formula for estimating average quality factor degradation in thermally processed foods in cylindrical containers
Authors: Garrote Raúl L. , Ré Roberto 
Published: March 2003

Summary A formula suggested by Jen et al. (1971) may be suitable for estimating the average retention of quality factors in conduction heated foods. This hypothesis was tested by comparing the results obtained for thiamine retention with calculations based on analytical and finite difference solutions of transient heat conduction in cylindrical containers. For a high Biot number, agreement was within 10.8% over a wide range of processing conditions (can size, retort temperature, initial temperature, etc).