bluuebunny/crossref_metadata_2025_split huggingface dataset:
External and internal macromorphology in 3D‐reconstructed maxillary molars using computerized X‐ray microtomography
Authors: Bjørndal L. , Carlsen O. , Thuesen G. , Darvann T. , Kreiborg S. 
Published: March 2003

Aim The aim of this study was to perform a qualitative analysis of the relationship between the external and internal macromorphology of the root complex and to use fractal dimension analysis to determine the correlation between the shape of the outer surface of the root and the shape of the root canal.Methodology On the basis of X‐ray computed transaxial microtomography, a qualitative and quantitative analysis of the external and internal macromorphology of the root complex in permanent maxillary molars was performed using well‐defined macromorphological variables and fractal dimension analysis. Five maxillary molars were placed between a microfocus X‐ray tube with a focal spot size of 0.07 mm, a Thomson‐SCF image intensifier, and a CCD camera compromising a detector for the tomograph. Between 100 and 240 tomographic 2D slices were made of each tooth. Assembling slices for 3D volume was carried out with subsequent median noise filtering. Segmentation into enamel, dentine and pulp space was achieved through thresholding followed by morphological filtering. Surface representations were then constructed. A useful visualization of the tooth was created by making the dental hard tissues transparent and the pulp chamber and root‐canal system opaque. On this basis it became possible to assess the relationship between the external and internal macromorphology of the crown and root complex.Results There was strong agreement between the number, position and cross‐section of the root canals and the number, position and degree of manifestation of the root complex macrostructures. Data from a fractal dimension analysis also showed a high correlation between the shape of the root canals and the corresponding roots.Conclusions It is suggested that these types of 3D volumes constitute a platform for preclinical training in fundamental endodontic procedures.
Comparison of measurements obtained with hand files or the Canal Leader attached to electronic apex locators: an in vitro study
Authors: Steffen H. , Splieth CH. , Behr K. 
Published: March 2003

Aim The aim of the present in‐vitro study was to combine directly the Canal Leader handpiece (SET, Olching, Germany) with the electronic apex locators ROOT ZX (Morita, Kyoto, Japan) and JUSTY (Yoshida, Tokyo, Japan) to find out whether the working length values thus obtained were identical to those resulting from the combination of the same electronic devices with hand files.Methodology A total of 50 natural extracted teeth with single canals and mature apices were used. A radiograph was used as a control and the distance from the radiographic apex to the tip of the file was measured and compared with the results of the electronic length determination.Results For both electronic devices the differences amongst the distribution of the measurements were not statistically significant under the specified conditions (P > 0.05), indicating that the measurements with hand files and with the Canal Leader were identical for the majority of the cases.Conclusions Under the conditions of this study the working length of canals obtained with electronically assisted hand files were similar to those obtained with the electronically assisted mechanical handpiece Canal Leader.
In vitro evaluation of the reliability of the Root ZX electronic apex locator
Authors: Ounsi H. F. , Naaman A. 
Published: March 2003

Aim An experimental comparison of the Root ZX apex locator with the real measurement of the root canal length was carried out using a saline gel to simulate the periodontium.Methodology Lengths were taken when the needle reached the 0.5 mark and the Apex mark on the meter. These measurements were then compared with a calculated reference length representing the real length of the root canal. Reliability was assessed using Student’s t‐test. Precision was assessed using the mean and standard deviation of differences.Results The Root ZX gave measurements within a range of 0.5 mm in 84.72% of the cases. The intra‐operator and inter‐operator variabilities were not statistically significant (P > 0.05).Conclusions The Root ZX is not capable of detecting the ‘0.5 mm from the foramen’ position and thus, should only be used to detect the foramen (major diameter).
Root canal anatomy of anterior and premolar teeth in Down’s syndrome
Authors: Kelsen A. E. , Love R. M. , Kieser J. A. , Herbison P. 
Published: March 2003

Aim The aim of this study was to examine tooth length and root canal anatomy of 281 anterior and premolar teeth from 66 DS individuals using a standard protocol.Results The results indicated that root canals in DS are relatively simple and that there is a significant reduction in root and crown length.Conclusions We propose that these observations are commensurate with the suggestion that trisomy 21 exerts its effect by slowing the mitotic cycle and rate of cell proliferation, resulting in generalized retardation of growth.
A comparison of root fracture resistance using two root canal sealers
Authors: Apicella M. J. , Loushine R. J. , West L. A. , Runyan D. A. 
Published: March 2003

Aim The aim of this study was to compare in vitro root fracture resistance following root canal filling with either Ketac‐Endo or Roth's root canal sealer.Methodology The roots of 40 teeth with single canals were instrumented and placed randomly into four groups of 10 teeth. The prepared canals were obturated with lateral compaction using gutta‐percha and Roth's 801 sealer, lateral compaction and Ketac‐Endo sealer or with a single cone and Ketac‐Endo sealer; the fourth group acted as unfilled controls. The roots were stored for 2 weeks in 100% humidity priorto being mounted in acrylic resin blocks. A steel tipped rod attached to an Instron testing machine was positioned against the canal opening and a slowly increasing force was applied until root fracture occurred. The results were subjected to statistical analysis using Kruskal–Wallis one‐way ANOVA.Results There were no significant differences between the groups in terms of force required to vertically fracture the roots.Conclusions Under the conditions of this study, the use of Ketac‐Endo sealer in conjunction with lateral compaction or single‐cone obturation techniques does not increase the fracture resistance of root‐filled teeth.
Development of a method to detect and quantify prostaglandin E2 in pulpal blood from cariously exposed, vital primary molar teeth
Authors: Waterhouse P. J. , Whitworth J. M. , Nunn J. H. 
Published: March 2003

Aim The aim of this in vitro study was to detect and quantify an established marker of inflammation, prostaglandin E2 (PGE2), in blood samples harvested from radicular pulp stumps after coronal pulp amputation.Methodology Harvesting was achieved by a paper strip ‘dip‐stick’ method and the volume of each sample estimated before storage at − 808C. A competitive, plate‐based enzyme immunoassay technique (EIA) was developed for detection and quantification of the inflammatory mediator assumed to be present in bloodsamples. Since this technique had not previously been used to assess pulp blood, steps in the development of harvesting, storage, extraction and validation of this sensitive assay are described.Results Thirty‐nine single‐blood samples were assayed and yielded detectable amounts of PGE2 ranging from 1.0 to 2641 ng mL − 1.Conclusions The results of this investigation indicate that the inflammatory mediator, PGE2 can be detected and quantified in small blood samples from pulp stumps. Further development may derive quantitative tests for determining the condition of pulp tissue in primary molar pulp treatment.
Periapical health related to the quality of root canal treatment in a Belgian population
Authors: De Moor R. J. G. , Hommez G. M. G. , De Boever J. G. , Delmé K. I. M. , Martens G. E. I. 
Published: March 2003

Aim  The aim of this study was to collect data on the prevalence and technical standard of root canal treatment as well as the prevalence of apical periodontitis in Belgium.Methodology The panoramic radiographs of 206 Belgian adults attending the Dental School of the University Hospital of Gent were examined for endodontic treatment, periapical conditions and coronal restorations.Results  Of the 4617 teeth examined, 6.8% were endodontically treated. Periapical radiolucencies were found in 6.6% of all teeth and in 40.4% of the endodontically treated teeth. More than half of the root‐filled teeth (56.7%) were scored inadequate on the basis of a criterion evaluating the level of the root canal filling.Conclusion  The endodontic treatment need of this Belgian subpopulation was great and the technical standard of root canal treatment disappointing. The findings indicate that there is still a substantial need for postgraduate endodontic education in Belgium and a need for specialists in endodontology.
A primary observation on the preparation and obturation of oval canals
Authors: Wu M‐K. , Wesselink P. R. 
Published: March 2003

AbstractAimThe aim of this study was to observe the existence and assess the quality of obturation of uninstrumented recesses in oval canals.MethodologyThe balanced force technique was used in two groups of oval canals in human mandibular incisors. The canals in group 1 were enlarged to conventional sizes, whereas canals in group 2 were enlarged more widely. All canals were obturated with cold laterally condensed gutta‐percha. Two horizontal sections were cut in the apical portion of each filled root. Images of the cross‐sections were scanned and analysed using the KS100 Imaging system.ResultsUninstrumented recesses appeared in 13 (65%) oval canals. The recesses in five of these 13 canals were obturated without visible voids. The recesses in the other eight canals were either obturated with visible voids or completely unfilled. The percentage of filled area was significantly higher in group 1 than in group 2 (P < 0.05).ConclusionsUninstrumented recesses may be left in many oval canals after preparation using the balanced force technique and these recesses may often not be completely obturated with cold laterally condensed gutta‐percha.
Periapical healing of mandibular molars after root‐end sealing with dentine‐bonded composite
Authors: Rud J. , Rud V. , Munksgaard E. C. 
Published: March 2003

AbstractAimThe purpose was to present the frequency of periapical healing in first and second/third mandibular molars, after root‐end resections sealed with a dentine‐bonded resin composite.MethodologyRoot‐end sealing of resected mandibular molar roots was made with dentine‐bonded composite (Gluma‐Retroplast) as a cover on the entire slightly hollowed root‐end, in an attempt to prevent leakage.ResultsOut of the 834 roots recalled between 6 months and 12.5 years postoperatively, 92% showed complete apical healing, 1% uncertain healing and 7% exhibited failure. The healing result of 681 first molar roots was not significantly different (P = 0.21) from that of 153 second/third molar roots, and there was no significant difference in healing between mesial and distal roots (P = 0.32 for first molars, P = 0.86 for second/third molars) or amongst six age groups (P = 0.94). In the patient group: 71–89 years, 36 roots showed an average of 97% with complete healing. Out of 25 failures who were retreated surgically, 80% showed complete healing when examined subsequently.ConclusionRoot‐end sealing of mandibular molars with dentine‐bonded resin composite is a promising technique giving 92% complete healing in cases examined between 6 months and 12 years postoperatively.
Failure of ProFile instruments used with high and low torque motors
Authors: Yared G. M. , Bou Dagher F. E. , Machtou P. 
Published: March 2003

AbstractAimThe purpose of this study was to evaluate the failure incidence of ProFile nickel–titanium rotary instruments when used in conjunction with different motors and a specific instrumentation technique.MethodologyProFile Ni–Ti rotary instruments (PRI) with 0.06 taper were used in a crown‐down technique. In groups 1, 2 and 3, an air, a high torque and a low torque motor were used, respectively. Each group included 30 canals in extracted human molars. One set of PRI sizes 40–15 was used for each canal; they were sterilized before each case. A 2.5% NaOCl solution was used as an irrigant. The number of deformed and separated instruments was recorded for the various experimental groups.ResultsInstrument separation did not occur in any of the three groups. One and two instruments were deformed when using the air and high torque motors, respectively.ConclusionsThe results indicated no difference between the three motors with respect to the incidence of instrument failure. The results suggest that the use of PRI in a crown‐down manner with air control motors was safe.
The long‐term sealing ability of an epoxy resin root canal sealer used with five gutta percha obturation techniques
Authors: De Moor R. J. G. , Hommez G. M. G. 
Published: March 2003

AbstractAim The aim of the present study was to evaluate the long‐term sealing ability (both apical and coronal) of an epoxy resin root canal sealer (AH26) when used with different gutta‐percha obturation techniques.Methodology Straight single‐rooted teeth with mature apices were divided into 10 groups of 75 teeth and one group of 40 control teeth. Root canals were prepared according to the crown‐down/step‐back technique and using both 2.5% sodium hypochlorite and an EDTA paste. Root canals were obturated using cold lateral condensation, warm vertical condensation and hybrid condensation of gutta‐percha; and with Thermafil and Soft‐Core obturators. AH26 was used as the sealer in all cases. After root canal filling, each group was divided into five individual groups of 15 teeth. The first group of 15 teeth was kept for 1 day, the second for 1 week, the third for 4 months, the fourth for 6 months and the fifth for 12 months at 37°C in vacutainers in 80% relative humidity. The teeth were immersed in India ink for 90 h, each root was split and sectioned longitudinally, and the maximum extent of leakage was measured using a stereomicroscope at ×6 magnification.Results Leakage occurred whatever filling technique was combined with AH26. The number of teeth with gross leakage increased with time up to 4 months, but did not appear to increase between 6 and 12 months storage. The degree of apical leakage and the number of leaking teeth in the Soft‐Core obturator groups was significantly higher than all four other gutta‐percha obturation techniques. Up to 4 months the degree of coronal leakage and the number of leaking teeth in the Thermafil groups was significantly higher than the other gutta‐percha obturation techniques, except for Soft‐Core. In the Soft‐Core obturator groups the degree of coronal leakage and the number of leaking teeth was significantly higher than the other gutta‐percha obturation techniques, except for Thermafil at all evaluation times.Conclusion The hybrid gutta‐percha condensation technique was superior to the other four obturation techniques in respect of apical leakage. Coronal leakage was significantly greater during the first 4 months for the Thermafil system as compared to the three condensation techniques; coronal leakage was significantly greater at all time periods for the Soft‐Core system. There were no significant differences between the Thermafil and the Soft‐core system.
Evaluation of smear layer removal by EDTAC and sodium hypochlorite with ultrasonic agitation
Authors: Guerisoli D. M. Z. , Marchesan M. A. , Walmsley A. D. , Lumley P. J. , Pecora J. D. 
Published: March 2003

AbstractAim To evaluate smear layer removal by different irrigating solutions under ultrasonic agitation.Methodology Twenty recently extracted mandibular incisors with a single root canal were divided into four equal groups. Three groups were instrumented using the modified double‐flared technique, the fourth remained unprepared. Each group was irrigated with either distilled water, 1.0% sodium hypochlorite alone or associated with 15% EDTAC between each file size. The final group was not instrumented but irrigated with 1.0% sodium hypochlorite and 15% EDTAC. A size 15 file energised by ultrasound was used with small amplitude filing movements against the canal walls in all groups. The teeth were split longitudinally and the roots measured to provide three sections of the same size (cervical, middle and apical). Samples were examined under the scanning electron microscope and assessed for the amount of smear layer by three independent and calibrated examiners. The scoring system ranged from 1 (no smear layer) to 4 (all areas covered by smear layer). Due to the non‐parametric nature of the data, Friedman’s test was used for statistical analysis.Results Canal walls were covered with smear layer in the group irrigated with 1% sodium hypochlorite alone and the group irrigated with distilled water. Canals irrigated with 1.0% sodium hypochlorite associated with 15% EDTAC had less smear layer throughout the canal (P < 0.001). There were no statistical differences for the amount of smear layer found on the cervical, middle and apical thirds when each group was analysed separately.Conclusions Under ultrasonic agitation, sodium hypochlorite associated with EDTAC removed the smear layer from root canal walls, whereas irrigation with distilled water or 1.0% sodium hypochlorite alone did not remove smear layer.
Electronic determination of root canal length in primary teeth with and without root resorption
Authors: Mente J. , Seidel J. , Buchalla W. , Koch M. J. 
Published: March 2003

AbstractAim To test an electrical device for determining root canal length in primary teeth in vitro, and to compare it with the radiographic length measurement.Methodology Two examiners determined the root canal length of 24 extracted maxillary primary incisors (12 with visible root resorption and 12 without) using an electrical root canal meter (Tri Auto ZX, Morita, Dietzenbach, Germany). The instrument was left in the root canal after the second examination and a radiograph was taken. The whole tooth was cleared by immersion in methylsalicylate and subsequently photographed. Both radiographs and photographs of cleared teeth were measured and compared with the electronic measurements.Results The evaluation of the radiographs showed a mean distance between the instrument tips and apices of 0.60 (± 0.41) mm; evaluation of the cleared teeth showed an equivalent distance of 0.62 (± 0.40) mm. The mean distance between instrument tip and acceptable working length (determined with the clearing method) was 0.26 (± 0.24) mm in teeth without resorption and 0.29 (± 0.30) mm in teeth with resorption.Conclusion The presence of resorption in primary teeth did not affect the accuracy of electrical measurement of root canal length in vitro. The application of this method in primary teeth should be evaluated further.
Collagen synthesis in rat skin and ileum fibroblasts is affected differently by diabetes‐related factors
Authors: VERHOFSTAD MICHIEL H.J. , BISSELING TANYA M. , HAANS ELOY M.H. , HENDRIKS THIJS 
Published: March 2003

Untreated diabetes reduces wound strength: a concomitant reduction in collagen deposition has been found in cutaneous wounds but not in intestinal anastomoses. This raises the question if collagen synthesis in fibroblasts from skin and intestine reacts differently to the diabetic state. Fibroblast lines were established from healthy rat skin and ileum. Diabetic rat serum was collected from hyperglycaemic rats 3 days after intravenous injection of streptozotocin (200 mg/kg). Fibroblast cultures were grown to confluency in foetal calf serum and maintained in various concentrations of glucose, insulin, normal or diabetic rat serum. Collagen synthesis was measured by incorporation of [3H]‐proline into Collagenase‐Digestible‐Protein.Collagen synthesis in fibroblasts from both skin and ileum was not affected by increasing glucose concentrations. Insulin strongly and specifically stimulated collagen synthesis in skin fibroblasts whereas in ileum fibroblasts only a nonspecific increase of total protein synthesis was observed. In skin fibroblasts, diabetic rat serum stimulated collagen synthesis to a significantly lesser extent than normal rat serum, whereas in ileum fibroblasts stimulation by serum was far less explicit and no difference was observed between normal and diabetic serum.The fact that ileum fibroblasts respond less strongly to culture in diabetic serum than skin fibroblasts may explain our prior finding that wound collagen accumulation in intestinal anastomoses is virtually unaffected during diabetes and supports the existence of tissue‐specific healing responses.
Animal models of acute hepatic failure
Authors: Manibur Rahman Tony , Hodgson  
Published: March 2003

The understanding and treatment of acute hepatic failure has developed rapidly over the last 40 years reducing morbidity and mortality from this syndrome. Progress has been made by the study of animal models that reflect the clinical, biochemical and histological pattern of the syndrome seen in man. This is of increasing importance with the use of therapeutic intervention, liver transplantation and the use of extra‐corporeal liver support devices.This review examines and critically appraises the various approaches to the study of acute hepatic failure in animal models, including both surgical and pharmacological approaches.
Caries prediction model in pre‐school children in Riyadh, Saudi Arabia
Authors: Al Ghanim  , Adenubi  , Wyne  , Khan  
Published: March 2003

Objectives. To evaluate the significance of variables such as oral hygiene, dietary habits, socio‐economic status and medical history of a child in assessing the level of caries risk and to generate a caries prediction model for pre‐school Saudi children.Design. Cross‐sectional study of pre‐school children.Setting. Clinics and schools in Riyadh, Saudi Arabia.Sample and methods. A sample of 446 Saudi pre‐school children, 199 males and 247 females, with a mean age of 4·13 years, were selected at random from clinics and schools. Selection was limited to subjects who either had no caries (dmft= 0) or who had high caries experience (dmft > 8). Each child was examined for caries experience and oral hygiene status. Their mothers were interviewed through a standardized questionnaire for information about oral hygiene habits of the children, diet history, childhood illness and socio‐economic status.Results. There was a highly significant difference between the two groups in: debris index (P<0.0001), age child started tooth brushing, (P<0·0001), age breastfeeding was stopped (P<0·005), nocturnal bottle feeding with milk formula (P<0·0001), use of sweetened milk (P<0·0001), frequency of use of soft drinks (P<0·0005), frequency of consumption of sweets (P<0·0001), and age at first dental visit (P<0·0001). A caries prediction model developed through stepwise multivariate Logistic Regression (LR) analyses showed debris index, use of sweetened milk in bottle, frequency of consumption of soft drinks, frequency of intake of sweets and child’s age at the first dental visit to be significant. Predictive probability of the model was 86·31% with a sensitivity of 90·1% and a specificity of 80·6%.Conclusions. Risk factors for dental caries have been identified and a caries prediction model has been developed for Saudi pre–school children. The prediction model, if verified, may provide dentists with guidance in identifying high caries risk Saudi pre‐school children as targets for preventive programmes