bluuebunny/crossref_metadata_2025 huggingface dataset:
Digital subtraction radiography for assessment of simulated root resorption cavities. Performance of conventional and reverse contrast modes
Authors: Hintze Hanne , Wenzel Ann , Andreasen Frances M. , Sewerin Ib
Published: April 2006

Abstract A previous study of the sensitivity and accuracy of a standardized radiographic technique for the disclosure of root cavities in a cadaver material indicated that it was not possible to perceive small artificial “resorption” cavities. Using the same material, the aim of the present study was to evaluate whether the use of subtraction radiography would improve the detection of root cavities. In an autopsy material of five mandibular blocks each containing two premolars, small, medium, and large cavities were drilled in the cervical, middle, and apical thirds of the proximal and oral root surfaces. Each jaw block was radiographed before (B) and after (A) cavity preparation with three different exposure times resulting in light, medium, and dark film densities. The radiographs were digitized. Digital subtraction was performed between the A‐ and B images of varying densities by a computer program developed for dental subtraction radiography. Conventional and reverse contrast modes of the subtraction image were assessed independently by four observers. The results showed small inter‐ and intraobserver differences in diagnostic accuracy for assessment of total number of root cavities. Original film density did not influence the diagnostic performance in the resulting subtraction image. Contrast mode in the subtraction image influenced diagnostic performance as the majority of observers did best with the reverse contrast mode (p<0.05). Some of the small root cavities were disclosed by the subtraction technique, but overall accuracy was not increased compared to conventional radiography.
Emergency dental management of a patient with von Willebrand's disease
Authors: Camm J. H. , Murata S. M.
Published: April 2006

Abstract A patient with von Willebrand's disease presenting for dental treatment requires thorough evaluation prior to the determination of a proper course of treatment. In this case report, a patient with von Willebrand's disease presented to the emergency room with dental trauma. A modified treatment plan, taking into account the severity of the patient's systemic illness and the need for medical management, yielded successful results.
Traumatic injuries to primary teeth in Mexico City children
Authors: del Rosario M. E. Llarena , Alfaro V. M. Acosta , Garcia‐Godoy F.
Published: April 2006

Abstract The purpose of this retrospective study was to analyse traumatic injuries to primary teeth in children attending an emergency dental service in a pediatric hospital in Mexico City. A total of 563 children 6‐mo to 7 yrs‐old were treated during the period from January 1981 to December 1987. The 563 children presented 936 traumatic dental injuries. The most common type of trauma was soft tissue injury, followed by luxation and avulsion. More males presented with traumatic injuries (61.8%) than females (38.2%). In both sexes, maxillary teeth received more traumatic injuries than mandibular teeth. Children 2‐3 yrs old presented the highest number of injuries (195) followed by the 4‐5 and 6‐7 year‐olds. The largest number of injuries were seen during winter (36%) followed by summer (25%), spring (21%) and fall (18%).
Influence of irrigation and intracanal dressing on the healing process of dogs’ teeth with apical periodontitis
Authors: Holland R. , Scares I. J. , Scares I. M.
Published: April 2006

Abstract Dogs’ teeth with apical periodontitis were treated endodontically, Dakin's solution being used in an experimental group as the irrigation solution, and camphorated paramono‐chlorophenol as an intracanal dresssing. For a second group of teeth, the irrigation solution used was physiologic saline, dry cotton only being placed into the pulpal chamber to take the place of an intracanal dressing. In a second visit, overinstrumentation and a new application of the same kind of dressing were performed, the root canals being then filled with gutta‐percha cones and zinc oxide‐eugenol cement. Other specimens were treated, in one visit, where physiologic saline or Dakin's solution were the irrigation solutions. The animals were sacrificed 6 months after the obturation of the root canals. Histologic exams showed better results for the experimental group where Dakin's solution and camphorated paramonochlorophenol had been used, with signs of repair characterized by newly formed cementum and bone tissue, as well as a marked reduction in size of the periapical lesions. No differences were seen in the results with physiologic saline or Dakin's solution as irrigants.
Traumatic gemination – triple tooth. Survey of the literature and report of a case
Authors: Çalişkan M. K.
Published: April 2006

Abstract Gemination and twinning are two rarely encountered developmental abnormalities. Although the precise etiology remains unknown, genetic predisposition is often suggested in the process. In the present study a maxillary incisor with three crowns of conical shape and three roots which were presumed to be the gemination of the tooth due to trauma, is reported.
Long‐term retention of a paper point in the periapical tissues: a case report
Authors: Sedgley C. M. , Messer H.
Published: April 2006

Abstract A case is reported of a 15 mm paper point found in the periapical area of a maxillary right central incisor during endodontic surgery for an unresolved periapical radiolucency. The paper point had been present for between live and nine years. Histopathological examination showed the presence of chronically inflamed fibrous connective tissue with a number of foreign body giant cells and focal collections of chronic inflammatory cells. SEM comparison of the specimen with a similarly treated fresh paper point showed no indication of degradation of the paper point by host defense cells.
In vitro evaluation of the effectiveness of calcium hydroxide and paramonochlorophenol on anaerobic bacteria from the root canal
Authors: Georgopoulou M. , Kontakiotis E. , Nakou M.
Published: April 2006

Abstract The effectiveness of calcium hydroxide and paramonochlorophenol (PMCP) was tested on anaerobic bacteria isolated from infected root canals, at time intervals 5, 15, 30 and 60 min. The experimental method used was similar to that proposed by the German Society of Hygiene and Microbiology (DGHM), with slight modifications. Testing revealed that calcium hydroxide was significantly more effective than PMCP against the total number of anaerobes. Additionaly, it was proved to be quickly and highly effective against some microorganisms related to severe clinical symptoms, such as B. melaninogenicus and P. gingivalis as well as against actinomyces species.
Root canal therapy of an anomalous maxillary central incisor: a case report
Authors: Pécora J. D. , Conrado C. A. , Zuccolotto W. G. , Neto M. D. Sousa , Saquy P. C.
Published: April 2006

Abstract A case of endodontic conservative treatment of a maxillary central incisor with an atypical crown and Type III dens invaginatus is presented. The greatest difficulty was to locate the root canals due to the atypical internal anatomy. There were not two clear canals, but the coronal pulp chamber showed two entrances to the root canal. The tooth presented a distal periodontal pocket and various lingual radicular grooves. The appearance of the crown was improved by alteration of its dimension using diamond rotary instruments and correction with photopolymerized resin.
Healing process of dogs' pulpless teeth after apicoectomy and root canal filling at different levels
Authors: Holland R. , Filho J. A. O. , Bernabé P. F. E. , de Souza V. , Nery M. J.
Published: April 2006

Abstract Dogs' teeth with infected root canals, were submitted to apicoectomy and the root canals were filled flush or 2 mm short. In a third group the canals were left unfilled and only the access openings were closed. One hundred and eighty days after the treatment, the animals were killed and the specimens prepared for histological analysis. Repair was not observed in the teeth with unfilled root canals. The healing observed in the teeth with root canals filled flush was less complete than the healing observed when the root canals were filled 2 mm short.
Effect of intracanal dressings on repair and apical bridging of teeth with incomplete root formation
Authors: Leonardo M. R. , da Silva L. A. Bezerra , Utrilla L. S. , de Toledo Leonardo R. , Consolaro A.
Published: April 2006

Abstract Periapical repair and apical bridging were studied in dog's teeth with incomplete root formation and induced chronic periapical lesions treated with different dressings. A total of 75 root canals from the upper and lower premolars of 4 dogs approximately 6 months of age were chemo‐mechanically prepared and filled with the following dressings: antibacterial dressing consisting of a calcium hydroxide + camphorated p‐monochlorophenol paste applied for 7 days and followed by monthly renewed calcium hydroxide paste as temporary dressing at 30, 60 and 90 days (Group A); antibacterial dressing consisting of camphorated p‐monochlorophenol alone for 7 days, followed by temporary dressing with calcium hydroxide paste renewed at 30, 60 and 90 days (Group B). A control group (Group C) received no dressings. Ninety days after the last calcium hydroxide paste (Groups A, B) and after the last irrigation/aspiration (Group C). The animals were killed, the maxillae and mandibles were removed, and the material submitted to routine histological processing and examination. Both root canal dressings, were of fundamental importance for apical repair and bridging. The apical bridging was predominantly complete in Group A, incomplete in Group B, and absent in Group C. The calcium hydroxide 4‐camphorated p‐monochlorophenol combination gave better results than camphorated p‐monochlorophenol alone.
Autotransplantations and loss of anterior teeth by trauma
Authors: Schatz Jean‐Paul , Joho Jean‐Pierre
Published: April 2006

Abstract The loss of anterior teeth by trauma has usually been corrected by orthodontic or prosthetic means. In some specific cases, however, the skeletal and dental relationship may contra‐indicate the use of space‐closure mechanics. Autotransplantation of teeth, successfully depicted in many clinical studies, can help to reduce the severity of orthodontic cases complicated by traumatized anterior teeth. A case report is presented to stress both the indications and limitations of such treatment.
Tactile sensitivity of three endodontic instrument handles
Authors: Treble Stephen John , Chandler Nicholas Paul , Shaw Joanna Robyn
Published: April 2006

Abstract Three currently available endodontic instrument handles, introduced over the past four decades, were investigated for tactility. Larger handles have been promoted to overcome sensitivity loss from wearing gloves. Smaller handles were preferred in this experiment. While the largest diameter handle appeared to give enhanced tactility, significance was not reached in any of the tests.
Systemic diseases caused by oral microorganisms
Authors: Debelian Gilberto J. , Olsen Ingar , Tronstad Leif
Published: April 2006

Abstract Human endodontic and periodontal infections are associated with complex microfloras in which approximately 150, (in apical periodontitis) and 350 (in marginal periodontitis) bacterial species have been encountered. These infections are predominantly anaerobic, with gram‐negative rods being the most common isolates. The anatomic closeness of this microflora to the bloodstream can facilitate bacteremia and systemic spread of bacterial by‐products and immunocomplexes. A variety of clinical procedures such as tooth extraction, periodontal and endodontic treatment, may cause translocation of microorganisms from the oral cavity to the bloodstream. The microorganisms that gain entrance to the blood circulate throughout the body, but are usually eliminated by the host (reticuloendothelial system) within minutes. However, in patients with ineffective heart valves or vascular diseases, bacteremia can be a potential danger, leading most commonly to infective endocarditis and myocardial or cerebral infarction. Other forms of systemic diseases such as brain abscesses, hematological infections and implant infections have also been related to oral microorganisms.
Evaluation of calcium hydroxide‐containing root canal sealers with an improved rabbit ear chamber
Authors: Wakabayashi H. , Ishiguro M. , Funato A. , Nakamura Y. , Matsumoto K.
Published: April 2006

Abstract An improved rabbit ear chamber was used to evaluate calcium hydroxide‐containing root canal sealers on their potential in induce dystrophic calcification in connective tissue. Four sealers and two control materials were introduced into the chambers and the effects of these materials on the living vascular tissue were observed continuously under a biomicroscope up to 9 weeks. Conventional histopathological investigation and examinations with a scanning electron microscope and an X‐ray microanalyzer were done to supplement the results. Sealapex and Calvital (Ca(OH)2+ iodoform) revealed almost the same tissue reaction as calcium hydroxide‐saline paste; they rapidly made a precipitate‐barrier of calcium phosphate in the connective tissue, inducing calcification. However, Dentalis KEZ(ZnO‐ca(OH)2+ eugenol) caused mild disorders of microcirculation without calcification, as well as Canals(ZnO + eugenol). New A (Ca(OH)2+ fatty acid) had good compatibility with micro‐vessels as well as New B(ZnO + fatty acid), however they induced no calcification and disintegrated rapidly in the tissue. These sealers were reclassified according to what they actually bring about in the tissue, not according to what they include.
Immnohistochemical examination on the localization of macrophages and plasma cells in induced rat periapical lesions
Authors: Akamine Akifumi , Hashinguchi Isamu , Toriya Yoshikazu , Maeda Katsumasa
Published: April 2006

Abstract – To investigate the role of plasma cells and macro‐phages in the development of periapical lesions, we immunohistochemically examined the distribution of these inflammatory cells in experimental induced rat periapical lesions after pulpectomy. The number of EDI‐positive mononuclear cells increased rapidly, reached a plateau which remained stable between days 10 and 60, and subsequently decreased. Immunoglobulin (Ig)‐bearing plasma cells appeared alter 60 days, and, of these, IgG‐bearing plasma cells were predominant after 90 days. The radio‐graphic and histopathological findings indicated the develop‐ment of bone destruction at 10 days which continued until 60 days; tissue repair began to take place after 90 days. The results suggested that macrophages had a close relation to bone destruc‐tion and that plasma cells might participate in tissue repair rather than the development of periapical lesions.
An in vitro investigation of Thermafil obturation at different temperatures
Authors: Felstead A. M. , Lumley P. J. , Harrington E.
Published: April 2006

Abstract – The apical leakage of lower premolars obturated with Thermafil at three different temperatures was investigated in vitro. The temperatures were determined after calibration of the Thermaprep oven. The root canals of 35 extracted teeth were prepared chemomechanically and divided into three groups of 10 each with a control group of five. The root canals of the experimental group were obturated using plastic Thermafil obturators at three different temperatures 144, 120 and 100 C with the controls being obturated using laterally condensed gutta percha. The teeth were suspended in indian ink for 28 days prior to being cleared and the degree of apical leakage assessed. The results showed no significant difference (p > 0.05) in the apical leakage of the teeth obturated with Thermafil compared to laterally condensed gutta percha. There was a trend towards less leakage in the teeth obturated with Thermafil at the lower temperatures, this, however, was not significant (p > 0.05).
Reaction of rat subcutaneous tissue to implants of gutta‐percha for endodontic use
Authors: Tavares T. , Scares I. J. , Silveira N. L.
Published: April 2006

Abstract The present work studied the reaction caused in the connective tissue of rats by implantation of two brands of gutta‐percha cones, and thermoplasticized gutta‐percha cylinders. Thirty‐six rats were used, in groups of 12, for periods of 15, 30, and 60 days. Each animal received one test implant of each material, and one implant of Teflon as control. The cylinders, and one of the brands of gutta‐percha cones, were well tolerated by the connective tissue. The cones of the other brand elicited different reactions, of which the possible causes are herein discussed.
Pulpal and periodontal reactions of immature permanent teeth in the dog to intrusive trauma
Authors: Cunha R. F. , Pavarini A. , Percinoto C. , de Oliveira Lima J. E.
Published: April 2006

Abstract Pulpal and periodontal tissues of immature incisors of 10 dogs were radiographically and histopathologically evaluated immediately, 7, 15, 30 and 60 days after experimental intrusion induced by mechanical blows. Forty upper central and mesial lateral incisors showing incomplete root formation on radiographs were submitted to intrusive force. After the observation periods, the dogs were killed, two at a time. The hemi‐maxilas were removed and processed for histopathologic examination. The traumatized teeth showed accelerated apical formation with reduced radicular length. Pulpal vitality was maintained and the subjacent tissues did not present irreversible changes. All traumatized teeth re‐erupted spontaneously.
Pulpal reaction to a dental adhesive in deep human cavities
Authors: Torstenson B.
Published: April 2006

Abstract In the last years several dental adhesives have been developed. They are supposed to chemically adhere to dentin and a liner to protect the pulp is not used. The aim of this study was to compare the short‐term pulpal reaction, in an intra‐toothpair study, between a dental adhesive, Scotchbond 2, and a lining system, Tubulitec, in combination with P‐50 in surface‐sealed cavities. Deep buccal cavities in 16 human pairs of premolars, 32 teeth, were restored in vivo with a light cured composite resin, P‐50. To minimize bacterial contamination all cavities were treated with a cleanser, Tubulicid, and the cavities were surface‐sealed with temporary cement, Coltosol. One tooth in each pair, the test, was treated with Scotchprep Dentin Primer and Scotchbond 2 Light Cure Dental Adhesive. In the other tooth in the pair, the control, Tubulitec Primer and Liner were used. The teeth were extracted after 6–14 days. The sections where evaluated for degree of inflammation and the presence of bacteria. Irrespective of treatment of dentin the majority of teeth, 23, including one pulpal exposure, revealed no inflammation or a few inflammatory cells. In four test teeth, including one pulpal exposure, and two controls, growth of bacteria was found on the cavity walls and slight or moderate inflammation was seen in the corresponding pulps. In one test and two control teeth slight inflammation was seen but no bacteria could be detected. In the absence of bacteria Scotchbond 2 did not seem to irritate the pulp. However, in almost one third of the restorations the bond strength to dentin was not sufficient to resist the contraction forces during polymerization as indicated by bacterial growth at the interface between dentin and adhesive/composite.
Clinical investigation of traumatic injuries of permanent incisors in Izmir, Türkiye
Authors: Çalişkan M. K. , Türkün M.
Published: April 2006

Abstract 470 injured teeth of 370 patients who consulted the Dental Clinic of Ege University, Izmir, Turkiye for examination of treatment between 1981–1993 were evaluated. Information concerning sex, age of patients at the time of injury, cause of trauma, number of injured teeth, type of tooth and type of trauma were recorded. More boys suffered traumatic injuries (64.8%) than girls (35.2%). Patients aged 11–15 years old exhibited the highest number of injuries (37.4%) followed by the 6–10 years old group (24.5%). Most injuries involved one tooth (60%) and maxillary central incisors were the most often affected teeth (66.2%). The leading cause of injury was undefined falls (45.1%). The most common type of trauma was non‐complicated crown fracture (40.4%). At the initial examination, cases seen after a long posttraumatic period showed more complications than those presented within a short time period. Educational programs about the importance of dental trauma, ways of preventing from trauma, the benefits of immediate attendance and conservation of avulsed and fractured teeth would be very helpful for patients. Additionally improving the knowledge of the dental practitioner about trauma would be another important point in solving the problem.
Evaluation of sealing ability, pH and flow rate of three calcium hydroxide‐based sealers
Authors: Siqueira J. F. , Fraga R. C. , Garcia P. F.
Published: April 2006

Abstract Three endodontic sealers containing calcium hydroxide (Sealapex, Sealer 26 and Apexit) and a zinc oxide‐eugenol cement (Grossman's sealer) were examined for sealing ability, release of hydroxyl ions and flow rate. Dye penetration test was used to assess the sealing ability of the endodontic sealers. The pH test was accomplished to evaluate the release of hydroxyl ions from sealers and the pH readings were done at intervals of 30 min, 60 min and 7 days. In the flow test the sealers were placed between two glass slabs and a weight of 500 g was placed on the top of the glass. The diameters of the formed discs were recorded. The results revealed no statistically significant difference between apical seal provided by the four sealers. All of the calcium hydroxide based sealers alkalinized the surrounding medium. Sealer 26 cement presented significantly superior flow rate when compared with the other cements. These findings indicated that endodontic sealers containing calcium hydroxide presented satisfactory physicochemical properties when compared with a zinc oxide‐eugenol sealer commonly used in endodontics.
Dentists' views on cervical hypersensitivity and their knowledge of its treatment
Authors: Schuurs A. H. B. , Wesselink P. R. , Eijkman M. A. J. , Duivenvoorden H. J.
Published: April 2006

Abstract A random sample of 400 Dutch general practitioners was asked to complete a questionnaire dealing with the prevalence, conditions and therapies of cervical hypersensitivity of their patients. According to the 259 responding dentists an average of 10% of their patients suffered from moderate cervical pain. The estimated mode for severe pain was 1%. More than two thirds of the dentists reported inadequate brushing of the teeth to cause the hypersensitivity, about one half acknowledged periodontal causes, well over one quarter mentioned the involvement of dietary acids, and about one sixth implicated psychosomatic factors. Other causal factors were mentioned less often. Of the therapies available, the home‐care methods appeared to be promoted most often, i.e. brushing with therapeutic toothpastes (77%), improvement of oral hygiene (51%) and local self‐application (with finger) of a therapeutic toothpaste or fluoride preparations before the night (41%). Well over 50% reported to apply occasionnally bondings/varnishes and 28% said to make sometimes cervical fillings. Other therapeutic possibilities were not, or very seldom, used.
Digital radiographic images will benefit endodontic services
Authors: Lavelle C. L. B. , Wu C.‐J.
Published: April 2006

Abstract Future assurances for endodontic services and assessments of traumatized teeth will depend in part on significant improvements to the quality of dental radiographs. Whereas digital images offer many potential sensor, display and archival advantages over film–based radiographs, the marginal image improvements from intraoral sensors primarily benefit patient education. Precisely digitized conventional radiographs are more likely to yield quantum image resolution improvements, although neither dentists nor patients will benefit until cost‐effective digitizing systems have been developed for the dental office.
Use of ultrafast computed tomography in dental surgery: a case report
Authors: Grimm W.‐D. , Wentz K. , Boedecker T. , Eberhard J. , Jackowski J. , Kamann W.
Published: April 2006

Abstract ‐ A case of a transdental fixation planned on the basis of ultrafast computed tomography is reported. This method allows to gain an insight in the osseous structures required for the operative procedure. Ultrafast computed tomography is superior to the convential radiographs in obtaining accurate information about the vertical bone supply and the extension of the facial osseous sinus wall. A set of axial CT‐images with an extension of 3 mm was acquired in the region of the alveolar bone. By means of frontal reconstructions and data processing methods the thickness of the bone layer in transverse direction was accurately determined. The calculated bone thickness allowed to anchor a transdental self‐tapping titanium screw.
Effect of various sealers with gutta‐percha as root‐end fillings on healing after replantation
Authors: Pitt Ford T. R. , Andreasen J. O. , Dorn S. O. , Kariyawasam S. P.
Published: April 2006

Abstract This study examined histologically the effect of three sealers used with gutta‐percha as root‐end fillings placed in a replantation model. A total of 14 molar teeth were used in seven monkeys. Alter extraction, root ends were resected, the canals contaminated with oral bacteria, root‐end cavities prepared, and fillings of gutta‐percha and sealer placed prior to replantation. After 8 weeks the teeth and surrounding Jaw were removed and prepared for histological examination. Six roots filled with gutta‐percha plus a fortified zinc oxide‐eugenol cement (IRM). 13 With gutta‐percha plus zinc oxide‐eugenol (EP), and eight with gutta‐percha pins Kloropercha. were available for examination. The tissue response to gutta‐percha with either Zinc oxide material was characterized by little or no inflammation of limited extent. In contrast, more severe inflammation was observed against root ends filled with gutta‐percha and Kloropercha. Gutta‐percha plus IRM or Zinc oxide‐eugenol had a much more favourable response than that to amalgam reported previously in a similar experiment.
Scanning electron microscopic observations of apical root surfaces of teeth with apical periodontitis
Authors: Lomçali G. , Şen B. H. , Çankaya H.
Published: April 2006

Abstract The aim of this study was to observe apical fool surfaces of teeth with chronic periapical lesions. Five premolars and three molars with radiographically demonstrable periapical lesions were extracted and fixed in 2.5% phosphate‐buffered glutaraldehyde solution For 9 days. The apical 3‐mm portion of 17 roots was removed and prepared for scanning electron microscope. Lacunar resorption zones were frequently observed on the root surfaces. Bacteria and yeast cells were detected in some of the lacunae. Periapical bacterial plaque with a smooth structure was present mostly around the main apical foramen. Cementum‐like tissue deposits indicative of repair were seen adjacent to some resorption areas. Clastic cells lightly attached to crater‐like depressions with linger‐like projections were observed laterally on the specimens. Current research should be focused on new procedures to eliminate extraradicular microrganisms and periapical bacterial plaque in persistent periapical infections.
Role of cementoenamel junction on the radicular penetration of 30% hydrogen peroxide during intracoronal bleaching in vitro
Authors: Koulaouzidou E. , Lambrianidis T. , Beltes P. , Lyroudia K. , Papadopoulos C.
Published: April 2006

Abstract Intracoronal bleaching of nonvital teeth with 30% hydrogen peroxide is occasionally associated with external cervical root resorption. The exact mechanism by which bleaching induced root resorption occurs is not yet fully understood. The relationship of cementum to the enamel at the cementoenamel junction may have clinical significance. Seventeen single rooted human mandibular premolars extracted atraumatically for orthodontic reasons were used. The radicular hydrogen peroxide penetration in each tooth was measured in vitro by an indirect colorimetric method. Thereafter, the teeth were examined with a scanning electron microscope to determine the type of the cementoenamel junction. It was found that the radicular penetration of 30% hydrogen peroxide was related to the type of cementoenamel junction.
Reasons for apicectomies. A retrospective study
Authors: El‐Swiah J. M. , Walker R. T.
Published: April 2006

Abstract A retrospective study was carried out to evaluate the clinical factors involved in deciding to perform apicectomies. Five hundred and seventeen teeth from 392 patients (211 women and 181 men) that had undergone apicectomy during the period from September, 1990 to December, 1992 were assessed using the patients’ clinical records. The information recorded included the source of referral, the quality of preoperative root canal filling, the size of periradicular lesion, the type of the lesion (for biopsed lesions), the type of coronal and radicular restorations, and the different factors that influenced the decision to perform an apicectomy for each tooth. These factors were classified into technical and biological, and when they occurred together they were classified as combined. The decisions to perform apicectomies most commonly involved combined technical and biological factors. Biological factors alone only amounted to 35% of the total. Technical factors alone amounted to only 3% of the total. When all (actors were considered, biological factors constituted 60%, whilst technical factors constituted 40%, of the total. The most common biological factors were persistent symptoms (54%), and continuing presence of a periradicular lesion (44%). The most common technical factors were post crown (60%) and crowned teeth without posts (31%). This study emphasised the need for a high standard of conventional root canal treatment in order lo avoid surgical treatment.
An in vitro study of the efficacy of mouthguard protection for dentoalveolar injuries in deciduous and mixed dentitions
Authors: Johnston T. , Messer L. B.
Published: April 2006

Abstract Sports‐related dental trauma remains a risk for children and adolescents. Although mouthguards provide protection, up to 25% of dentoalveolar injuries can occur with a mouthguard in place. This study examined the effect of mouthguard protection in an in vitro model. A total of 97 sheep mandibular segments with incisors at four developmental stages (early deciduous, ED, 11 = 37; middle deciduous, MD, n = 20; late deciduous, LD, n=18; mixed dentition, PD, 11 = 22) was used. Customised pressure formed mouthguards (MG) provided protection from trauma produced by a servohyclraulic materials testing machine to test incisors. Injuries were examined clinically, radiographically and by dissection. Mean forces required to produce dentoalveolar injury were significantly greater in test (with MG) teetli than control (no MG) teeth. Mean forces to produce injury in test teeth decreased with resorbing root lengths. Deciduous incisors differed in injury type: subluxalions and horizontal root fractures predominated in test teeth; lateral luxations and horizontal root fractures in control teeth. Predominant injuries in test and control permanent incisors were enamel infractions and snblnxations. The magnitude of lateral luxation measurements of individual teeth was reduced significantly by mouthguard protection in both deciduous and permanent dentitions. The mouthguard tended to increase the mobility of the teeth it encompassed and, in some instances, promoted dentoalveolar injury of adjacent teeth.
Bacterial penetration of the root canal of intact incisor teeth after a simulated traumatic injury.
Authors: Love R. M.
Published: April 2006

Abstract One of the aims in treating traumatiseed teeth is to maintain the vitality of the pulp or allow conditions favourable for pulp revaseularisation. However, infection of the pulp and root canal system may prevent this. A number of pathways have been proposed that allow bacteria to invade the root canal system, however most of these pathways cannot account for pulp infection in teeth that did not sustain injury to the periodontal attachment. Enamel/dentine cracks have been proposed as a portal for backrial invasion of seemingly intact teeth and the aim of this study was to determine if bacteria could invade the root canal system after a simulated traumatic episode. Twenty intact and sound upper central incisors were chosen and prepared. One tooth was selected as a sterility control and the external crown surface of the remaining 19 teeth was subjected to infection with Streptococcus gordonii in a bacterial microleak‐age model. Over 7 days samples of growth media from the root canal system were taken and tested for bacteria. Sixteen of the teeth did not demonstrate bacterial invasion over the time frame. These teeth were then prepared for testing in a pendulum impact device and were subjected to a blow which did not fracture the crowns or dislodge the tooth from its simulated alveolus. The teeth were then prepared and tested in the bacterial microleakagc model. After impact seven of the teeth demonstrated bacterial invasion of the root canal system (P=0.002). These teeth were then rcprcpared lor testing in the bacterial microleakagc model. The crowns of live teeth, selected at random, were coated with two layers of light cured unfilled resin, tin‐remaining two were used as positive controls. All the teeth coated with resin did not demonstrate bacterial invasion (P=0.00), while the positive controls demonstrated invasion. The results suggested that enamel/dentine infractions were pathways for bacterial invasion of the root canal system of traumatiscd teeth. The application of unfilled resin to the anatomical crown prevented infection.
Comparison of lipopolysaccharides from Bacteroides, Porphyromonas, Prevotella, Campylobacter and Wolinella spp. by Tricine‐SDS‐PAGE
Authors: Firoozkoohi J. , Zandi H. , Olsen I.
Published: April 2006

Abstract Lipopolysaccharides (LPSs) of 11 bacterial strains from the type species of the genera Bacteroides (B, fragilis), Prevotella (Pr. melaninogenica), Porphyromonas (Po. gingivalis), Canmpylobacter (C. fetus subsp. fetus), and Wolinella (W. succinogens), and from the type strains of B. distasonis, B. forythus, B. ureolyticus, Po. levii, Po. macacae, and C. gracilis, were extracted with hot water‐phenol (Westphal method). S‐form LPSs, obtained from all organisms, were well resolved with tricine‐sodium‐dodecyl‐sulphate polyacrylamide gel electrophoresis and visualized by silver staining. Lipid A was not stained. Also profiles from LPS of Escherichia coli, serotypes 0111:B4 and 055:B5, could be distinguished. While W. succinogenes showed a relatively short S‐form LPS on electrophoregrams, the other bacteria, including B. fragilis, exhibited long‐ladder LPSs. Po. gingivalis displayed the largest number of bands and the longest O‐chain. The long O‐chain of this bacterium may be important for its virulence.
Electrical impedance measurements of root canal length
Authors: Meredith N. , Gulabivala K.
Published: April 2006

Abstract Electronic methods are now widely used during endodontic treatment for the assessment of root canal length. These commonly measure the electrical resistance or impedance between the root canal and the buccal mucosa. A number of studies have been undertaken to determine the accuracy of commercially available instruments. The aims of this investigation were to determine the electrical impedance characteristics of the root canal and periapical tissues in vivo, measure the changes relative to the distance of an endodontic instrument from the apical constriction and propose an equivalent circuit modelling the periapical tissues. The length of the root canals of 20 previously untreated teeth were determined using radiographic and electronic methods. Minimal canal preparation was carried out and measurements were made with a size 10 K‐Flex file. A microprocessor‐controlled LCR analyser was used to measure the electrical impedance characteristics of each root canal. The instrument measured the series and parallel resistive (Rs, Rp) and capacitance (C$, CP) component of the tissues at two test frequencies, 100 Hz and 1 kHz. Measurements were made for each root canal when the diagnostic file was placed at the apical constriction and repeated when the file was withdrawn to ‐0.5, ‐ 1.0, ‐ 1.5, ‐2.0 and ‐5.0 mm from the foramen. Readings were taken for each canal after the canal had been dried with paper points, and flooded first with deionisecl water and then with sodium hypo‐chlorite. The root canals were then prepared, cleaned and obturated using standard endodontic procedures. The LCR analyser selected the series resistance component as the major measurement parameter. There was a clear increase in series resistance (Rs) with increasing distance from the radiographic apex for dry canals and those containing deionised water and sodium hypochlorite. The mean resistance for dry canals was markedly higher than for those containing fluid, ranging from 22.19 kd to 92.07 kω in comparison with 9.32 kω to 12.10 kω for deionised water and from 7.46 kω to 8.92 kω for canals containing sodium hypochlorite. There was a marked change in the series and parallel resistive component with distance from the apex, suggesting a complex relationship between the impedance of the smear layer and bulk dentine. The impedance characteristics of a root canal were a complex electrical network comprising resistive and capacitive series and parallel elements.
Crown‐root fracture of lower molar – restorative procedures
Authors: Theodossopoulou J. N.
Published: April 2006

Abstract Endodontically treated teeth may undergo crown, crown‐root, or root fractures. The treatment of fractured teeth can be complicated, sometimes because of difficulties with the final restoration. This case report describes a case of crown‐root fracture of a left lower first molar in which endodontic treatment and rapid orthodontic eruption of the tooth made a good prosthetic restoration possible.
Hemisection and vital treatment of a fused tooth – literature review and case report
Authors: Hülsmann M. , Bahr R. , Grohmann U.
Published: April 2006

Abstract Fusion and gemination of permanent teeth are developmental anomalies of the dental hard tissues which may require endodontic and surgical treatment for functional, orthodontic or aesthetic reasons. Following a review of the dental literature on tooth fusion and gemination, a case of fusion of a maxillary central incisor and a supernumerary tooth and its endodontic and surgical treatment is presented.
Survival of avulsed permanent maxillary incisors in children following delayed replantation
Authors: Barrett E. J. , Kenny D. J.
Published: April 2006

AbstractThe purpose of this study was to identify the variables that significantly influenced the survival of incisors replanted after extended extraalveolar duration at The Hospital for Sick Children, Toronto, Canada, between June 1988 and December 1993. Survival analysis was used to identify variables that significantly influence the retention of replanted incisor teeth. Survival was defined as the time that elapsed between the replantation of an avulsed incisor and the time it was finally lost. Information on 9 variables was collected for 3H patients (25 males; 13 females) and 52 replanted permanent maxillary incisors. The mean extraalveolar duration for the sample was 123 min. The mean follow‐up interval was 942 days (range: 364–2126 days). Incisors replanted with open apices had a significantly decreased survival compared with teeth with mature apices (P=0.04; relative risk 4.2). There was also a significant association between increased survival and obturation of the root canal with gutta‐percha and sealerP=0.006 relative risk 10.0). A trend towards improved survival of replanted incisors was found for children older than I 1 years old at the time of replantation (P= 0.09; relative risk 2.8). These results are consistent with previous studies and may assist clinicians and parents in the decision‐making process associated with the management of avulsed teeth in children.
Effect of calcium hydroxide dressing on seal of permanent root filling
Authors: Kontakiotis E. G. , Wu M.‐K. , Wesselink P. R.
Published: April 2006

Abstract Low apical leakage along root fillings following an application of calcium hydroxide was reported in a few methylene blue dye penetration studies. It has been found recently that methylene blue is decolored by calcium hydroxide, indicating that the short penetration of methylene blue may not be due to a tight seal only. Of the 80 roots of human maxillary central incisors used in this study, 40 roots (group 1) received calcium hydroxide root canal dressing whereas another 40 roots (group 2) did not. All the roots were then obturated with gutta‐percha and Tubli‐Seal sealer. Leakage along 20 filled roots in each group was measured using a modified fluid transport model at 48 h, 2, 4, 8 and 16 weeks after obturation; whereas leakage of another 20 filled roots in each group was measured using dye penetration with 1% methylene blue. Using the fluid transport model, no significant difference was found between the two groups at any time interval (P=0.4847, 0.3875, 0.9490, 0.4786, 0.9148 respectively after 48 h, 2, 4, 8 and 16 weeks); using the methylene blue penetration method, leakage in group 1 (with root canal dressing) was significantly less than that in group 2 (without root canal dressing) P=0.0374). The contradiction in results from the different models indicated that problems existed with the models.
Apical leakage in canals filled with glass ionomer sealer and gutta‐percha after dentin conditioning
Authors: Raiden G. , Olguín A. , Peralta G. , Posleman I. , Lagarrigue G.
Published: April 2006

Abstract This study assessed in vitro apical leakage in root canals filled with gutta‐percha and Ketac‐Endo using different dentin conditioning and filling techniques. The root canals of 63 single‐rooted teeth were instrumented and randomly divided into the following four groups: group A – canals were irrigated with 25% tannic: acid and filled with Ketac‐Endo and a standardized gutta‐percha cone; group B – canals were irrigated with 1% NaOCl and filled as in group A; group C – canals were irrigated with 25% tannic acid and filled with Ketac‐Endo and a chloroform‐softened gutta‐percha cone adapted to the canal walls; group D – canals were irrigated with 1 % NaOCl and filled with Grossman's sealer and laterally condensed gutta‐percha. After storage for 72 hours at 37°C and 100% humidity, the gutta‐percha was removed to a level 4 mm short of the working length, using a Peeso reamer. Teeth were immersed in India ink for 48 hours and cleared, and the coronal extent of dye penetration examined under a binocular dissecting microscope at × 15 magnification. The mean value of leakage for group A was 0.86 mm, for group B 2.23 mm, for group G 2.34 mm, and for group D 0.55 mm. Tukey's multiple comparison lest disclosed significant differences (P<0.05) between group A and groups B and C, and between group D and groups B and C. Differences between groups A and D, as well as between groups B and C, were not significant.
MICROFLUIDICS‐BASED OPTICAL BIOSENSING METHOD FOR RAPID DETECTION OF ESCHERICHIA COLI O157:H7
Authors: LI YANBIN , SU XIAO‐LI
Published: April 2006

Microbial contamination of food products causes foodborne diseases and related costs, presenting an urgent need for the rapid detection of bacterial pathogens in food samples. In this research, a microfluidics‐based optical biosensing method was investigated for the rapid detection of Escherichia coli O157:H7, and specifically the performance of microfluidic channels was evaluated. The biosensing system consisted of a syringe pump for sample/reagent delivery, an antibody‐modified microfluidic channel as a bioseparator/bioreactor for bacterial capture and enzymatic amplification and an optical detector for signal measurement. Affinity‐purified anti‐E. coli O157:H7 antibodies were chemically immobilized onto the inner wall of microfluidic channels. The immobilized antibodies captured target bacteria in a sample being pumped through the microfluidic channel. Sandwich complexes of immobilized antibody–target bacteria‐labeled antibody were formed in the channel after alkaline phosphatase‐labeled antibodies passed through. Then, p‐nitrophenyl phosphate was injected into the channel as the substrate of the alkaline phosphatase conjugates, and the absorbance of the enzymatic product, 4‐nitrophenol, was measured at its maximum absorption wavelength of 402 nm. The results indicate that the microfluidics‐based optical biosensing method was able to detect E. coli O157:H7 with a detection limit of 10–100 cfu/mL in 2 h without any enrichment. The absorbance was not significantly different among the microfluidic channels with different lengths from 10 to 60 cm. Interference from generic E. coli and other bacterial species was negligible. The microfluidic channel designed as the bioseparator/bioreactor showed its advantages in improved immunoassay kinetics and minimized reagent consumption and its potentials for automated operation and portable biosensors.
A plea for rationality in the law of murder
Authors: Wilson William
Published: April 2006

It is generally agreed that the law of murder is in need of reform. The scope of the reform necessary has however become the subject of increasingly robust debate. The retreat from Hyam, it has been argued, leaves us with a law of murder which is both too wide and too narrow to justify the continued bifurcation of murder and manslaughter. believe this objection to be justified but consider equally that the substantive aims of a two-tiered law of homicide are not, as some believe, incompatible with doctrinal rationality. The task of criminal lawyers therefore must be to attempt to effect the necessary reconciliation of substance with form. I shall argue that central to this enterprise is the maintenance of the dividing line between intentional and reckless killings but that a definition of intention must be adopted which incorporates certain categories of risk-taking. As the definition now stands, the wrong categories are incorporated at the expense of the right ones.
Towards a European criminal jurisprudence? The justification of criminal law by the Strasbourg court
Authors: Bengoetxea Joxerramon , Jung Heike
Published: April 2006

The European Convention for the Protection of Human Rights and Fundamental Freedoms (hereafter the Convention) has been in operation for almost 40 years, the Commission and the court for more than 30 years. In the meantime, recourse to Strasbourg has become a built-in mechanism of judicial review in the Member States. In particular, art 25 of the Convention which entitles individuals to plead a violation of the Convention has turned into a corner-stone of a working system of human rights protection, since the court's first decision in 1960. Even though the court's output cannot compare to internal state jurisdictions, applications to Strasbourg have risen dramatically over the years.
‘To the uttermost ends of the earth’? The War Crimes Act and international law
Authors: Cunningham Andrew J.
Published: April 2006

‘The National Socialist rulers of Germany invented new ways of controlling the policy and action of other countries without subjecting them to a formal military occupation, and some day it may be necessary for our courts to consider whether conduct equivalent to the German practice of establishing complete and effective domination over professedly neutral countries by insinuating agents and specialist troops into key positions, while permitting their governments nominally to continue to exercise their functions, as a prelude to plunging them into war, amounts to enemy occupation or not’