bluuebunny/crossref_metadata_2025_split huggingface dataset:
An in vitro investigation of the bulk flow of fluid through apical foramina during simulated tooth extraction: a potential confounder in microbiological studies?
Authors: Kapalas A. , Spratt D. A. , Ng Y‐L. , Gulabivala K. 
Published: March 2003

Aim The ‘pumping action’ induced during tooth extraction may cause bacteria suspended in tissue fluids to be transposed from one anatomical compartment to another. Apart from causing bacteraemia, this may lead to inaccuracies in studies evaluating the presence and distribution of bacteria in and around tooth apices. The aim was to investigate the bulk flow of fluid through apical foramina during simulated extraction of teeth in an in vitro model. The influence of the presence or absence of a coronal restoration was also evaluated. Methodology Twenty extracted single‐rooted, human, mature, permanent teeth were used. Standard access cavities were prepared and the root canals located. Standardized micrographs of the apical foramina were obtained and their area (µm2) was calculated by image analysis software. The teeth were then set and sealed into polyvinylsiloxane (rubber base) impression material. Crystal violet dye was inoculated into the coronal half of the root canal system. Tooth extraction movements were simulated in the impression matrix and the leakage of dyes with and without the presence of a coronal restoration was examined. The procedure was repeated, following application of safranin dye in a coronal trough within the simulated rubber base gingival margin at the CEJ. The results were analysed statistically with the independent‐samples t‐test and the McNemar test. Results In the absence of a coronal restoration crystal violet leaked out of the apical foramina in 18/20 teeth; conversely safranin leaked into the teeth through the apical foramina in 11/20 cases when applied to the external root surface. In the presence of an intact coronal restoration crystal violet dye leaked out in 6/20 teeth and conversely safranin leaked into 7/20 teeth. The presence of a coronal restoration significantly reduced (P = 0.002) dye leakage out of the root canal system. No associations were found for leakage of dye into the root canal system when applied externally. In addition, the amount of dye leakage was positively correlated with the area of the apical foramen in the presence of a coronal restoration (P = 0.009). Conclusion The presence of a coronal restoration significantly reduced leakage of dye out of the apical foramen. Microbiological studies on root canals and periapical lesions using extracted teeth should take potential contamination from this source into account.
An in vitro comparison of three thermal gutta percha systems
Authors: Horrocks M. P. , Qualtrough A. 
Published: March 2003

Aim The aim of this study was to compare the ability of three contemporary obturation techniques to resist microleakage, using root canals prepared in extracted single rooted teeth by a standardized method. Methodology The shaping technique involved the use of tapered nickel titanium rotary files to create a uniform 0.08‐mm/mm taper. Six groups were compared, two representing control groups, a third group being obturated with a warm vertical condensation technique, a fourth group by an injection thermoplasticized system, a fifth group with a thermomechanical compaction method and a sixth group using cold lateral condensation. A zinc oxide/eugenol sealer was used as the sealant in all the obturation procedures. Forty‐six extracted teeth were used in the study, three teeth in each control group and 10 teeth in each of the remaining four groups. Microleakage was compared using dye leakage with Indian ink. Penetration of the dye at the gutta percha/dentine interface was visualized after the root had been rendered transparent. Dye leakage was then measured from four aspects with the use of a stereomicroscope and export of a digital image to a software package, to facilitate accurate assessment of dye penetration. Two parameters were measured for each sample, the mean dye penetration and maximum dye penetration. Results The mean values for linear dye leakage in the thermomechanical compaction group was 0.53 mm, the warm vertical condensation group was 0.73 mm, the injection thermoplasticized group was 0.15 mm and the cold lateral condensation group was 0.53 mm. There was no statistical difference between the means of the different groups (P > 0.05). The mean of the maximum values for dye leakage in the thermomechanical compaction group was 0.65 mm, the warm vertical condensation group was 1.02 mm, the injection‐thermoplasticized group was 0.28 mm and the cold lateral condensation group was 0.74 mm. There was no statistical difference between the means of the different groups (P > 0.05). Conclusions Within the conditions of this study, there was no statistical difference between the different groups with respect to either mean or maximum dye leakage.
The dentinogenic effect of mineral trioxide aggregate (MTA) in short‐term capping experiments
Authors: Tziafas D. , Pantelidou O. , Alvanou A. , Belibasakis G. , Papadimitriou S. 
Published: March 2003

AbstractAim The objective of the present experiment was to study the early pulpal cell response and the onset of reparative dentine formation after capping application of MTA in mechanically exposed pulps.Methodology Thirty‐three teeth from three dogs, 12–18 months of age were mechanically exposed via class V cavities. Light pressure was applied to control haemorrhage. ProRoot MTA (Dentsply Simfra, Paris) was placed at the exposure site and light pressure was applied with a wet cotton pellet. The cavities were restored with amalgam and the pulpal tissue reactions were assessed by light and electron microscopy (transmission and scanning) after healing intervals of 1, 2 or 3 weeks.Results A homogenous zone of crystalline structures was initially found along the pulp–MTA interface, whilst pulpal cells showing changes in their cytological and functional state were arranged in close proximity to the crystals. Deposition of hard tissue of osteotypic form was found in all teeth in direct contact with the capping material and the associated crystalline structures. Formation of reparative dentine (tubular matrix formation in a polar predentine‐like pattern by elongated polarized cells) was consistently related to a firm osteodentinal zone.Conclusions The present experiments indicate that MTA is an effective pulp‐capping material, able to stimulate reparative dentine formation by the stereotypic defensive mechanism of early pulpal wound healing.
Incompletely fractured teeth associated with diffuse longstanding orofacial pain: diagnosis and treatment outcome
Authors: Brynjulfsen A. , Fristad I. , Grevstad T. , Hals‐Kvinnsland I. 
Published: March 2003

AbstractAim To evaluate the diagnostic value of different clinical findings, and analyse the symptoms experienced from teeth with incomplete dentinal fractures in patients with diffuse orofacial pain. Secondly, to present the outcome of different treatment modalities in these patients.Methodology Thirty‐two patients, referred to the teaching clinic at the Faculty of Dentistry, University of Bergen, with poorly localized orofacial pain, were finally diagnosed with 46 incompletely fractured teeth. The distribution and pattern of pain was thoroughly recorded for each patient. The final diagnosis, incompletely fractured tooth, was obtained after removal of fillings and direct inspection of possible fracture lines.Results Many of the patients had suffered diffuse orofacial pain for more than 1 year, and had earlier consulted dental and medical expertise. Direct inspection of fracture lines, combined with staining solution and transillumination proved to be the best diagnostic tools. The longer the duration of pain before the diagnosis of an incompletely fractured tooth was established, the more diffuse was the distribution of pain. Endodontic or restorative treatment relieved the symptoms in 90% of the patients, whilst persisting symptoms in 10% were considered part of an orofacial pain complex of obscure aetiology.Conclusion This study shows that the diagnosis of the incompletely fractured teeth in patients with longstanding diffuse orofacial pain symptoms are time consuming and represent a diagnostic problem. With appropriate endodontic and/or restorative treatment, symptoms were relieved in the majority of cases.
Immunohistochemical localization of V‐ATPases in rat spermatids
Authors: Kawa Gen , Yamamoto Akitsugu , Yoshimori Tamotsu , Muguruma Koei , Matsuda Tadashi , Moriyama Yoshinori 
Published: March 2003

The sperm acrosome exhibits a low pH. However, the mechanism of acidification in the acrosome remains unclear. Vacuolar‐type proton ATPase (V‐ATPase) has been shown to play a principle role in generating and maintaining the acidity of organelles such as lysosomes and endosomes. In this study, we examined whether V‐ATPase is localized in the acrosome membranes using immunohistochemical techniques.Sections of rat testis were immunostained using antibodies against V‐ATPase. Under light microscopic observation, the perinuclear region in spermatids at an early stage of development was heavily immunostained. At the electron microscopic level, gold particles showing the presence of V‐ATPase were localized to the acrosome membranes in the developing spermatids. V‐ATPase was also localized to the membrane of vesicles locating between the trans‐Golgi area and the acrosome. These observations suggest that V‐ATPase may play a role in acrosome acidification.
Sperm DNA damage and cancer treatment1
Authors: Morris Ian D. 
Published: March 2003

SummaryCancer treatments are well known to adversely affect male fertility. Reduction of sperm output arises from the cytotoxic effects of chemo‐ or radiotherapy upon the spermatogenic epithelium. However, if the epithelium survives there is a hazard to reproduction as the treatments are also mutagenic. The presence of DNA damage in the male genome is shown in animal experiments where there is transgenerational expression as a variety of effects ranging from miscarriage to carcinogenesis. The application of DNA damage methodology to sperm provides the opportunity for direct assessment. The Comet and Chromatin structure assays (SCSA) measure DNA damage by different principles, however, conclusions arising from the data are similar. DNA damage is present in sperm from fertile and infertile men and there is some association with infertility. Both assays detect sperm DNA damage after in vivo treatment with genotoxic agents. In a man treated with chemotherapy for cancer there was increased and persistent DNA damage in sperm. This information is consistent with the generation of human genetic diseases after conception with sperm carrying high loads of DNA damage. Whilst studies have not supported any association between paternal cytotoxic cancer therapy and genetic disease in their children, it would be unwise to discount these observations. The institution of better surveillance of genetic disease in the offspring of men surviving cytotoxic therapies may provide more robust risk assessment.
Characterization of the fertility of Kit haplodeficient male mice
Authors: GUERIF F. , CADORET V. , PLAT M. , MAGISTRINI M. , LANSAC J. , HOCHEREAU‐DE REVIERS M. T. , ROYERE D. 
Published: March 2003

SummaryThe role of the proto‐oncogene Kit expression during gonadal development, then in differentiated spermatogonia has been thoroughly established. The present study was designed to investigate the consequences of a partial defect in Kit gene expression on sperm fertilizing ability, using Kit haplodeficient mice (kitW‐lacZ/+). Same inbred mice (kit+/+) were used as controls. Epididymal sperm characteristics and in vivo fertility were assessed, then in vitro‐fertilization experiments were carried out for mice of both genotypes. Epididymal sperm count was drastically reduced, and sperm motility was also decreased in kitW‐lacZ/+ compared with kit+/+ males. Both in vivo or in vitro fertility were greatly reduced in kitW‐lacZ/+ compared with kit+/+ males. By contrast, the fertility of kitW‐lacZ/+ females was apparently unaffected. Additionally, a higher number of spermatozoa with undetected acrosomal contents was revealed by fluorescein isothiocyanate‐labelled Pisum sativum agglutinin acrosomal staining after epididymal sperm retrieval in kitW‐lacZ/+ mice, whereas no difference was observed after induction of acrosomal reaction in mice of either genotype. Ultra‐structural data confirmed the higher frequency of abnormal acrosome in spermatozoa of kitW‐lacZ/+ mice. Thus, sperm production is impaired in Kit haplodeficient mice both on a quantitative and a qualitative basis. Finally, we show that one single copy of Kit gene is not sufficient to maintain genuine fertility in male mice.
Androgen receptor and prostate cancer invasion1
Authors: Bonaccorsi Lorella , Muratori Monica , Carloni Vinicio , Zecchi Sandra , Formigli Lucia , Forti Gianni , Baldi Elisabetta 
Published: March 2003

SummaryEvidence indicates that androgen‐sensitive prostate cancer cells have a lower malignant potential. We previously demonstrated that expression of androgen receptor (AR) by transfection of the androgen‐independent prostate cancer cell line PC3 decreases invasion and adhesion of these cells through modulation of α6β4 expression. Treatment with the androgen further reduced adhesion and invasion of the cells without, however, modifying α6β4. Here we investigated whether the androgen has a direct effect on α6β4‐EGF receptor (EGFR) interaction and signalling leading to invasion of these cells. Immunoconfocal microscopy demonstrated that in control cells (PC3‐Neo), α6β4 and EGFR colocalize and redistribute in response to epidermal growth factor (EGF). In PC3‐AR cells colocalization and redistribution between the two molecules was reduced and abolished by pre‐treatment with R1881. Co‐immunoprecipitation studies demonstrated that tyrosine phosphorylation of β4 in response to EGF was reduced in PC3‐AR cells compared to PC3‐Neo. Immunoconfocal and co‐immunoprecipitation studies demonstrated colocalization at membrane level and co‐immunoprecipitation of EGFR and AR, indicating an interaction between the two proteins. PI3K activity, a key signalling pathway for invasion of these cells, was decreased in PC3‐AR cells in response to EGF and further reduced by treatment with R1881. EGFR internalization was strongly reduced in PC3‐AR compared with PC3‐Neo cells and was reduced by treatment with R1881. In conclusion, the expression of AR by transfection in PC3 cells confers a less malignant phenotype by interfering with EGFR‐‐α6β4 interaction and signalling leading to invasion through a mechanism involving an interaction between the classic AR and EGFR.
The chronology and sequence of eruption of human permanent teeth in Northern Ireland
Authors: Kochhar R. , Richardson A. 
Published: March 2003

Objectives. To ascertain the average and range of ages and sequence of eruption of human permanent teeth, taking into account the effect of premature loss of primary antecedents.Design. Longitudinal study.Setting. Caucasian subjects in Northern Ireland.Sample and methods. Study casts at 6‐monthly intervals from age 5 to 15 years of 276 children (146 males and 130 females) enrolled in the Belfast Growth Study. The mean and range of ages of eruption of each individual tooth were computed. Comparisons were made between the mean ages of eruption with and without premature loss of primary antecedents, between upper and lower arches, between right and left sides and between males and females. The sequence of eruption was also investigated.Results. The means and ranges of eruption ages are reported. Premature loss of primary antecedents delayed eruption of permanent successors except for the upper premolars which were accelerated. The differences relating to the upper first premolar and lower canine were not statistically significant. Each lower tooth erupted before its upper counterpart except for the premolars. There was no significant difference in age of eruption between right and left sides. Females tended to erupt teeth before males with the exception of the second molars in both arches; however, the only differences to reach statistical significance related to upper and lower canines and upper lateral incisors. The most frequent orders of eruption were unique to the subject. These occurred in 22% of upper and 33% of lower arches. The classic sequences: first molar–central incisor–lateral incisor–first premolar–canine–second premolar–second molar (M1‐I1‐I2‐PM1‐C‐PM2‐M2) in the upper arch and I1‐M1‐I2‐C‐PM1‐PM2‐M2 in the lower arch occurred in only 16% of upper arches and 13% of lower arches. Males adhered to the textbook sequence (20% upper, 17% lower) more than females (12% upper, 8% lower). In the upper arch of females, the order M1‐I1‐I2‐PM1‐PM2‐C‐M2 in 10% of subjects was almost as frequent as the classic sequence.Conclusion. The ages, ranges and orders of eruption found in this study are more reliable than many which are frequently quoted on account of its longitudinal nature and the fact that the effect of premature loss of primary antecedents is taken into account. The exclusively Caucasian sample makes the data quite precise but limits applicability to patients of this ethnic origin.
Oral health behaviour of 12‐year‐old children in Kuwait
Authors: Vigild M. , Petersen P.E. , Hadi R. 
Published: March 2003

Objectives. The objectives of the study were: (1) to describe the pattern of oral health behaviour of 12‐year‐old children in Kuwait, (2) to analyse this in relation to parental education, dental visiting habits and location, and (3) to establish a baseline for planning and evaluation of an oral health care programme for secondary schoolchildren. Design. Cross‐sectional, interviews with children in 1995. Sample and methods. The sample included 500 12‐year‐old schoolchildren (250 boys and 250 girls) selected from schools in Kuwait. All the children agreed to take part. Interviews with the children were carried out in the schools by four trained and calibrated Arabic speaking interviewers. Results. During the previous 12 months, 28% of the children had experienced oral health problems – toothache (10%), or had felt discomfort (18%) either often or occassionally. The children reported that they needed oral hygiene instruction (71%), fillings (32%) and tooth extraction (23%). For 53% of the children the reason for the most recent visit to a dentist was pain or problems with teeth or gums. At their last dental visit 26% of the children had undergone a tooth extraction. The consumption of sugary foods and drinks was extremely high. Children who had visited a dentist within the last 12 months and children whose parents had higher education levels more often claimed frequent toothbrushing than those with no previous dental visiting experience and those whose parents had a low level of education. Conclusions. Oral health education and oral health care programmes should be established in secondary schools in Kuwait to influence the oral health behaviour of the children and to avoid further deterioration in their oral health.
Traditional tooth bud gouging in a Ugandan family: a report involving three sisters
Authors: Dewhurst S.N. , Mason C. 
Published: March 2003

It has been reported in the literature that some rural populations of Sub‐Saharan and Eastern Africa and other isolated areas around the world, practise gouging or enucleation of primary tooth buds to cure childhood illnesses. The unerupted primary canine tooth bud is believed to be the cause of febrile illness, diarrhoea, and vomiting; prevalent in infants in these areas of the world.Tooth bud gouging has implications for the developing dentition, and is a potential risk to the health and life of the child. Reported prevalence ranges from 22%‐90%.From the information in this case report, the practise of tooth bud gouging is no longer confined to rural areas and may well be performed by communities that have emigrated to the UK. The three sisters described, now resident in the UK, suffered tooth gouging in a city clinic in Uganda. The damage caused to the primary and permanent dentition is described and treatment planning and options are suggested for each case to restore structure and function.Appropriate provision of healthcare and education could avoid the potential long‐term damage to the health of the child and their developing dentition by the practise of tooth bud gouging, whether it occurs in the developing or developed world.
Factitial oral lesions in an autistic paediatric patient
Authors: Medina A. C. , Sogbe R. , Gómez‐Rey A. M. , Mata M. 
Published: March 2003

Summary.Self Injurious Behaviour (SIB) is a deliberate harm to the body that may lead to factitial injuries. Its origin may be functional or biological and it has a higher prevalence in females and in psychologically impaired individuals. Seventy per cent of autistic patients have SIB. Seventy‐five per cent of factitial injuries are located in the head and neck region. A paediatric case report concerning a 4‐year‐old autistic female is presented. Detailed medical history, physical examination, clinical intraoral and radiographic examination, incisional biopsy, neuropaediatrical, psychological and speech evaluation were undertaken. Diagnosis included hypochromic macrocytic anaemia, caries, coronal fracture, factitial ulcer, factitial periodontitis, self‐extraction of primary teeth and permanent teeth buds, non‐specific oral ulcer with inflammatory reaction, mild mental retardation, speech impairment, autistic syndrome and self injurious behaviour consisting of putting fingers and foreign objects in the gingiva, fingernail biting and hair pulling. Differential diagnosis included hystiocitosis X, prepuberal periodontitis and leukocyte adhesion deficiency. Dental preventive and restorative treatment was performed. Non‐contingent reinforcement therapy was successfully used to diminish SIB. Treatment of factitial oral injuries must be interdisciplinary and requires cooperation of the patient, the parents, health care providers, and medical team.
Close encounters: the use of critical reflective analysis as an evaluation tool in teaching and learning
Authors: Chambers Nadia 
Published: March 2003

Close encounters: the use of critical reflective analysis as an evaluation tool in teaching and learning¶ Teaching and learning are complex activities which, when combined with professional practice‐based activity, take on additional dimension and depth. This makes the use of traditional, product‐based evaluation problematic in that a purely empirical approach does not facilitate thorough evaluation of every facet of such an encounter.This paper describes the use of critical reflective analysis as an alternative method of evaluation. The reflective framework facilitating this process has been adapted from three key sources: patterns of nursing knowledge; evaluative paradigms based upon knowledge — constitutive interests; descriptors for a reflective practicum. The reflective activity is structured around a teaching and learning encounter in a care‐based setting and focuses on `doing the drug round'. Descriptive vignettes are used to facilitate reflection‐on‐action and, through critical reflective analysis, the author identifies the essential value (e‐value‐ation) of the encounter in terms of credibility, utility and worth.