bluuebunny/crossref_metadata_2025_split huggingface dataset:
Lateral breakdown of nonendodontic origin adjacent to maxillary left incisors
Authors: Fristad I. , Hagen S. O. , Bårdsen A. , Molven O. 
Published: March 2003

AbstractCase reportA 16‐year‐old female presented with a labial fistula located between the central and lateral left maxillary incisors. The teeth had normal colour, responded positively to pulp testing, demonstrated negative percussion tests and had no evidence of periodontal pockets. The patient reported no history of trauma, but mentioned that she had received orthodontic treatment. Radiographic examination showed bone loss between these two teeth. Explorative surgery followed by antibiotic treatment was performed, but a fistula reappeared after 22 months. Surgical retreatment combined with antibiotic treatment resulted in gradual healing over a three‐year period. No root canal treatment was performed. Aetiological considerations connected to tissue injury and inflammation are discussed. Inflammation induced disturbances in local homeostasis may possibly explain the lateral breakdown of bone. Such areas of reduced resistance may, under unfavourable conditions, be infected by blood‐born pathogens. Information about such aberrant cases is important in endodontic decision making.
Effect of exposing dentine to sodium hypochlorite and calcium hydroxide on its flexural strength and elastic modulus
Authors: Grigoratos D. , Knowles J. , Ng Y‐L. , Gulabivala K. 
Published: March 2003

AbstractAimThe aim of this study was to evaluate the effect of sodium hypochlorite (NaOCl) solutions (3%, 5%) and saturated calcium hydroxide (Ca(OH)2) solution, individually and consecutively, on the flexural strength and modulus of elasticity of standardized dentine bars.MethodologyStandardized plano‐parallel dentine bars (n = 121) were divided into five test groups and one control group. The control group 1 consisted of dentine bars, stored in normal saline until testing. The dentine bars in the five test groups were treated by exposure to the following solutions; group 2 – 3% NaOCl, 2 h; group 3 – 5% NaOCl, 2 h; group 4 – saturated Ca(OH)2 solution, 1 week; group 5 – 3% NaOCl, 2 h and then saturated Ca(OH)2 solution 1 week; group 6 – 5% NaOCl, 2 h and then saturated Ca(OH)2 solution 1 week. The dentine bars were then loaded to failure in a three‐point bend test.ResultsThe data revealed a significant (P < 0.001) decrease in the modulus of elasticity and flexural strength of the dentine bars treated with 3% and 5% NaOCl. There was no significant difference in the flexural strength and the modulus of elasticity between the 3% and 5% NaOCl groups. Exposure to Ca(OH)2 significantly (P < 0.001) reduced the flexural strength but had no significant effect on the modulus of elasticity. The groups treated with sodium hypochlorite followed by calcium hydroxide did not have moduli of elasticity and flexural strengths that were significantly different from those treated only with sodium hypochlorite.ConclusionsNaOCl (3 & 5%) reduced the modulus of elasticity and flexural strength of dentine. Saturated Ca(OH)2 reduced the flexural strength of dentine but not the modulus of elasticity. Sequential use of NaOCl and Ca(OH)2 has no additional weakening effect.
Effect of access cavity location and design on degree and distribution of instrumented root canal surface in maxillary anterior teeth
Authors: Mannan G. , Smallwood E. R. , Gulabivala K. 
Published: March 2003

AbstractAim The null hypothesis tested in this study was that in single‐rooted anterior teeth with simple root canal anatomy, different access cavity designs (‘lingual cingulum’, ‘lingual conventional’, ‘incisal straight‐line’) do not influence the ability of endodontic files to plane the walls of the root canals.Methodology  Thirty extracted human maxillary anterior teeth were divided randomly into three groups for each access cavity. The access cavities were prepared according to predefined criteria and the roots embedded in individual polyvinyl‐siloxane putty matrices. The matrices allowed these teeth to be split into buccal and palatal halves and to be reassembled. The split teeth enabled removal of pulpal remnants from the root canal system and the walls to be stained with an even layer of permanent black ink. Once dried, the split roots were reassembled in the putty matrices and a step‐back filing technique was used to prepare the canals with water irrigation. The canal walls were examined for residual ink staining and scored by three independent assessors using an index devised for the purpose.Results There was good agreement between the assessors. None of the access cavities allowed file contact with the entire root canal wall. The overall (palatal and buccal sections) scores showed significant differences (P < 0.01) between the access cavity groups in the extent to which the canal walls could be filed. The straight‐line incisal access cavity had the greatest proportion of instrumented root canal surface. The lingual cingulum access cavity was the worst in this respect. The differences in residual ink scores between the access cavity types were significant for the buccal halves (P < 0.01) but not for the palatal halves (P > 0.05).Conclusions The null hypothesis was proven. Regardless of access cavity design, mechanical preparation did not allow instrumentation of the entire root canal wall. Straight‐line access allowed the greatest proportion of the root canal wall to be instrumented and the lingual cingulum access the least.
The influence of two concentrations of sodium hypochlorite on human blood: changes in haemolysis, pH and protein
Authors: Yamaguchi H. , Hosoya N. , Kobayashi K. , Yokota T. , Arai T. , Nakamura J. , Cox C. F. 
Published: March 2003

AbstractAim To evaluate the in vitro effect of 2.5% and 5.0% sodium hypochlorite (NaOCl) on human blood.Methodology Each concentration of NaOCl was reacted with human blood for 5 min at volume ratios of 1 : 1, 1 : 6, 1 : 12, each creating changes in colour, pH and temperature. Reaction suspensions were separated by centrifugation, and absorption measurements made for separated bilirubin, Fe, and protein supernatants. Each supernatant was desalted, lyophilized, and treated by SDS polyacrylamide gel electrophoresis (SOS‐PAGE).Results Increased ratios and concentrations of NaOCl caused an increase in both pH and temperature. Protein supernatants tended to decompose on SDS‐PAGE. Supernatants showed increased decolourisation with 5.0% NaOCl. Concentrations of bilirubin, Ferrum and protein in supernatants decreased with increased NaOCl concentration. NaOCl had an effect on the protein component in blood.Conclusions These data suggest that changes in molecular structure are due to the chemical effects of NaOCl. Protein bands tended to show low molecular weight, suggesting that haemoglobin components effect the oxidation‐reduction reaction.
Three phosphor plate systems and film compared for imaging root canals
Authors: Shearer A. C. , Mullane E. , Macfarlane T. V. , Gröndahl H.‐G. , Horner K. 
Published: March 2003

AbstractAimThe aim of this study was to compare three phosphor plate intraoral imaging systems (Digora (DA), Digident (DT), Denoptix (DX)) and E‐speed conventional film (CF) for the imaging of root canals.MethodologySixty extracted permanent teeth were exposed using CF, DA, DT and DX. The length of root canal visible from its most apical extent to a line drawn at the level of the cementoenamel junction was measured and this was expressed as a percentage of the distance between the radiographic apex and the cementoenamel line. All images were examined concurrently by two examiners. Films were viewed under standardized conditions and DA, DT and DX images were viewed directly from the monitor screen. The images on the monitor were enhanced to give the subjectively clearest image.ResultsThe mean percentage of canal visible on CF was 90%, DA 78%, DT 81% and DX 83%. The difference was significant for CF–DA (P < 0.001) and CF–DT (P = 0.001). There was no statistically significant difference for CF–DX or between any of the three phosphor plate imaging systems.ConclusionsIt is concluded that a greater length of root canal was visible on conventional film than on three phosphor plate imaging systems and that this may be of clinical significance.
Methodological considerations in the determination of working length
Authors: Martínez‐Lozano M. A. , Forner‐Navarro L. , Sánchez‐Cortés J. L. , Llena‐Puy C. 
Published: March 2003

AbstractAimThe aim of this study was to evaluate the diagnostic efficacy of an electronic system for the determination of working length, in comparison with two radiological methods (conventional film and digital radiography).MethodologyThe study sample consisted of 28 root canals belonging to 20 human mandibular teeth. A comparison was made between the working length measurements obtained by two radiological methods (conventional film and digital radiography) and an apex locator, using as gold standard the observation of the file position within the root following selective grinding of the root tissue.ResultsThe electronic method was satisfactory in 67.8% of cases, versus 50.6% and 61.4% for the conventional and digital radiological methods, respectively. No statistically significant differences occurred between the techniques according to the chi‐squared and Kruskal–Wallis nonparametric tests.ConclusionsNone of the techniques was totally satisfactory in establishing the true working length. There were no differences between the techniques investigated.
Quality of cold and warm gutta‐percha fillings in oval canals in mandibular premolars
Authors: Wu M‐K. , Kašt'áková A. , Wesselink P. R. 
Published: March 2003

AbstractAimThe aim of this study was to determine the quality of cold and warm gutta‐percha fillings in oval canals.MethodologyTwo groups of mandibular premolars with oval canals were selected after bucco‐lingual and mesio‐distal radiographs indicated an internal long : short diameter of ≥1.6 at a level 5 mm from the apex. After instrumentation they were obturated, respectively, by cold lateral compaction of gutta‐percha cones (cold GP) and vertical compaction of warm gutta‐percha (warm GP). Leakage along apical root fillings was measured using a fluid transport model. After the leakage test, horizontal sections were cut 2 and 4 mm from the apex. The area of the canal and gutta‐percha in cross‐sections was measured using an image analysis program. The quality of root fillings was evaluated by calculating the percentage of gutta‐percha‐filled canal area (PGP).ResultsNo significant difference in leakage was found between the two groups (P = 0.570). The warm GP group produced significantly higher PGPs than the cold GP group 4 mm from the apex only (P = 0.522 at 2 mm; P = 0.000 at 4 mm).ConclusionsThe percentage of gutta‐percha‐filled canal area using warm GP was greater than that of the cold GP in oval canals.
Guided bone regeneration (GBR) using membranes and calcium sulphate after apicectomy: a comparative histomorphometrical study
Authors: Yoshikawa G. , Murashima Y. , Wadachi R. , Sawada N. , Suda H. 
Published: March 2003

AbstractAim The purpose of the present study was to evaluate the effects of resorbable and non‐resorbable membranes, and calcium sulphate on bone regeneration in osseous defects in conjunction with apicectomy.Methodology The mandibular third and fourth premolars of 12 beagle dogs were root treated, and apicectomies were performed. The osseous defects were divided randomly into five groups. In groups A, B and C the osseous defects were covered with e‐PTFE membranes, PLGA membranes, and collagen membranes, respectively. In group D, defects were filled with calcium sulphate. Nothing was used in group E, which served as controls. The dogs were sacrificed 4, 8, and 16 weeks after the surgery. Undemineralized sections were obtained and evaluated histomorphometrically.Results Newly formed cortical bone had closed the defect in the cortical plate in all groups at 16 weeks. The degree of concavity of the new cortical bone at 16 weeks in groups A and D was significantly less than in group B (P < 0.01). The percentage of regenerated bone in group A was significantly greater than in groups B (P < 0.01), C (P < 0.05) and E (P < 0.05). In group D, it was significantly greater than in groups B (P < 0.01) and E (P < 0.05).Conclusions The data suggests that e‐PTFE membrane is more effective compared to resorbable membranes and controls for bone regeneration after apicectomy, and that calcium sulphate could be substituted for e‐PTFE membrane.
Effects of rotary instruments and ultrasonic irrigation on debris and smear layer scores: a scanning electron microscopic study
Authors: Mayer B. E. , Peters O. A. , Barbakow F. 
Published: March 2003

AbstractAim This study evaluated debris and smear layer scores after two types of instruments manufactured from different alloys were used to ultrasonically activate irrigants during canal preparation. The influence of two rotary preparation techniques on cleanliness of the shaped canals was also studied.Methodology Apical stops were prepared to size 45 in 42 single‐canalled extracted premolars and canines, which were divided into six equal groups. Groups 1, 2 and 3 were prepared by ProFile .04 (PF) while groups 4, 5 and 6 were prepared by Lightspeed (LS). All groups were irrigated using 5.25% NaOCl and 17% EDTA. Irrigants in groups 2 and 5 were ultrasonically activated using a size 15 steel K‐file and by a blunt flexible nickel–titanium wire in groups 3 and 6. Groups 1 and 4 served as negative controls. Roots were split and canal walls examined at 15×, 200× and 400× magnification in an SEM. Smear layer and debris scores were recorded at 3, 6 and 9 mm levels using a 5‐step scoring scale and a 200‐µm grid. Means were tested for significance using nonparametric Mann–Whitney U and Kruskal–Wallis tests.Results Debris and smear layer scores for the six groups varied from 1.98 ± 1.04 to 3.47 ± 0.97 and from 1.37 ± 0.4 to 2.36 ± 0.99, respectively. Although all groups had significantly higher smear layer and debris scores at the 3 mm levels compared to the 9 mm levels (P < 0.05), no significant differences were recorded due to the ultrasonic energy transmitted by the two alloys.Conclusion Ultrasonically activated irrigants did not reduce debris or smear layer scores. This finding was not influenced by the material nor by the design of the instrument used to transmit ultrasonic activation.
Antioxidant status in delayed healing type of wounds
Authors: Rasik Anamika M. , Shukla Arti 
Published: March 2003

This investigation studied the contribution of antioxidants in delaying healing in excision cutaneous wounds (8 mm) in diabetic, aged and immunocompromised animals. Skin levels of catalase, glutathione (GSH), ascorbic acid (AA) and vitamin E in streptozotocin‐induced diabetic rat were lower as compared to nondiabetics. The 7‐d wound tissue of diabetic rats showed an increased vitamin E level along with depleted GSH content. In aged rats (18 months old), higher levels of skin superoxide dismutase (SOD), glutathione peroxidase (Gpx) and thiobarbituric acid reactive substances (TBARS) and lower levels of catalase and GSH were found as compared to their values in young rats (3–4 months old). The levels of SOD, GPx, catalase, AA, GSH and vitamin E in 7‐d wound tissue of aged rats were significantly lower in comparison to those in young rats. However, TBARS were elevated in these wound tissues. The non‐wounded skin of immunocompromised (athymic) mice showed lower levels of SOD, catalase, and TBARS and higher GSH and GPx levels in comparison to those present in normal mouse skin. Surprisingly, the analysis of 7‐d wound tissue showed higher levels of SOD, catalase, GPx, and GSH and lower TBARS level in athymic mice compared to the wound tissue of normal mice.Thus low levels of antioxidants accompanied by raised levels of markers of free radical damage play a significant role in delaying wound healing in aged rats. In diabetic rats reduced glutathione levels may have a contributory role in delaying the healing process. However, in immunocompromised mice the antioxidant status following injury showed an adapted response.
Control of microbial growth on rice sprouts
Authors: Piernas Valérie , Piernas Valérie , Guiraud Joseph P. , Guiraud Joseph P. 
Published: March 2003

SummaryDifferent methods were investigated to prevent microbial hazards during rice sprouting. Disinfection of rice seeds before germination resulted in an immediate but temporary fall in microbial counts, except for minor populations (e.g. coliforms growing at 44 °C), which were totally eliminated. The levels were otherwise back to those of unsanitized seeds 24 h later. In‐process sprays of chlorinated water failed to limit the growth of residual bacteria. Post‐harvest decontamination was considered to improve the microbiological quality of sprouts. Experiments with artificially inoculated seeds demonstrated that immersing sprouts for 5 min in 60 °C water could decrease potential Listeria contamination to a safe level but that immersion would have no effect on the numbers of Bacillus cereus unless the temperature was increased to 100 °C.
Effects of the indigenous microflora of minimally processed lettuce on the survival and growth of Listeria innocua
Authors: Francis Gillian A. , O'Beirne David 
Published: March 2003

Interactions between the natural background microflora of shredded lettuce and Listeria innocua (in lieu of Listeria monocytogenes) were studied. The effect of increasing the initial size of indigenous populations (from 103 to 106–107 CFU g−1) was tested for its ability to reduce L. innocua growth on shredded lettuce. Co‐culture experiments were performed in model media, where bacterial isolates from the indigenous microflora were tested for possible inhibitory effects. Varying the size of the indigenous populations had no effect on L. innocua survival or growth. However, interactions with individual species and mixed populations from lettuce did affect the survival and growth of L. innocua in model media. In general, mixed populations diminished L. innocua growth. In the undiluted lettuce medium, the various species tested individually either reduced or did not affect the growth of L. innocua. However, when the medium was diluted, some species extended the survival of L. innocua. Competition between the indigenous microflora and L. innocua resided mostly with the Enterobacter spp. and not with the pseudomonads. Enterobacter cloacae was particularly effective in reducing L. innocua growth. Lactic acid bacteria also reduced L. innocua growth in undiluted media. It is concluded that interactions with the natural background microflora may play an important role in determining the dynamics of Listeria populations on shredded lettuce.
Antibiotic use in aquaculture: development of antibiotic resistance – potential for consumer health risks*
Authors: Alderman D. J. , Hastings T. S. 
Published: March 2003

SummaryAs aquaculture has developed, a range of bacterial diseases have been encountered that have caused both major production problems and animal welfare difficulties. These diseases were initially controlled almost exclusively by the use of antimicrobial agents. Fish farming is now a sufficiently large and mature an industry to have justified the development of an effective range of vaccines that have largely supplanted the use of antimicrobial agents for most bacterial diseases in salmonid farming in Europe and North America. For most salmonid bacterial diseases, use of antimicrobial agents is now largely confined to emergency use in the event of breakdown of vaccine protection. In addition to the increasing availability of vaccines, aquaculture is steadily developing a range of improved husbandry methods to reduce the impact of disease. Although there is evidence that antibiotic resistance can be selected for in normal therapeutic use in aquaculture, the risks of transfer of such resistance to human consumers by any of the possible routes appears to be low. Where new species are under development for aquaculture and during the development of these species, bacterial diseases may be expected to occur that will need use of antimicrobials for disease control before vaccines can be developed. If antimicrobials were not available for use with new species, development would be likely to transfer to countries with poorer controls on antibiotic use. Use of antimicrobial agents in ornamental fish, particularly in some exporting countries, is significant, and evidence exists that multiple antibiotic resistant bacteria may be frequent in such animals. Although ornamental fish are not eaten, they do enter homes and are in close contact with humans.
Aquaculture production and potential for food safety hazards in sub‐Saharan Africa: with special reference to Malwai*
Authors: Chimatiro S. K. 
Published: March 2003

SummaryAquaculture in Africa accounts for less than 2% of total domestic fish production. Although its contribution has expanded significantly from 59 000 Mt in 1985 to 85 000 Mt in 1990, the estimated potential is 3.5 million Mt per year. Of the 20 major species cultured, only Nile tilapia, African catfish and common carp are farmed throughout Africa. The leading fish culture producers, Cote d'Ivoire, Egypt, Kenya, Nigeria, South Africa, Tunisia and Zambia, accounted for more than 95% of production in 1990. Production has remained static in many countries (e.g. Cameroon, Ghana and Nigeria) and has decreased in others (e.g. Madagascar, Uganda). The potential for aquaculture in the Southern African Development Community (SADC) region is 250 000 t year−1 (present production is 5000 t year−1). Extensive, small‐scale fish farming has expanded in Malawi, Mozambique, Tanzania and Zimbabwe, where there are some 25 000 fish ponds. Fish farming has virtually ceased in Angola and is negligible in other SADC countries. In South Africa, production increased 663% between 1982 and 1992, the fastest growth in the world. Aquaculture development in South Africa has been market driven, dominated by large‐scale producers and no small‐scale operators. Potential health hazards from aquaculture products arise from either contaminants that find their way into the fish during the process of farming (feed additives, drugs) or loss of quality due to poor handling and processing. Poor handling is the greatest potential food safety issue in sub‐Saharan Africa, because much of aquaculture production is undertaken by small‐scale farmers who grow and handle relatively small quantities. About 90% of the fish from capture fisheries in Africa is preserved by means of smoking or roasting (40%) and sun drying (50%). However, the bulk of fish from small‐scale rural aquaculture is sold fresh, whole and ungutted at the pond site. Although the FAO Code of Conduct for Responsible Fisheries and the FAO/WHO Codex Alimentarius Commission make provisions for regulating standards, there are no functional mechanisms to monitor and enforce standards in many countries in sub‐Saharan Africa (probably with the exception of South Africa). There is a need to define ‘reasonable’ critical control points that can easily be achieved by many aquaculture operators in the region. Information flow from produces to consumers and documentation of food safety hazards must also be established, and functional at national and regional level.