bluuebunny/crossref_metadata_2025 huggingface dataset:
Eosinophilic granulorna of the mandible—a case report
Authors: MOLVEN O. , HALSE A. , HANSEN O. K.
Published: September 2007

Abstract. This is a case report of a patient who bad an eosinophilic granuloma of the mandible. The lesion was initially considered to be a periapical granuloma associated with an infected pulp in a lower incisor. After the lesion failed to respond to treatment the patient was referred to hospital where a biopsy was performed. Once the diagnosis had been established the affected lower incisors were removed and the lesion curetted. One year later there has been no recurrence.
Emergency treatment—a review
Authors: WALKER RICHARD T.
Published: September 2007

Abstract. This review examines emergencies that occur prior to, during, or immediately after endodontic treatment. The range of treatments, from very little to a great deal, are discussed in relation to irreversibly damaged vital pulps, necrotic pulps and alveolar abscesses. It is concluded that there has been a significant trend towards effective treatment of the emergency by complete instrumentation and sealing of the coronal access at the initial appointment. The need to clean the root canal system and prevent its subsequent infection by the oral flora is stressed.
The relationship between periodontal and pulpal disease
Authors: GULDENER P. H. A.
Published: September 2007

Summary. The relationship between periodontal disease and pulpal disease is reviewed by first considering their pathogenesis and differential diagnosis. The author then proposes a classification of lesions based mainly on their aetiology; this is primary endodontic lesion, primary periodontal lesion and combined lesion. The treatment of the various types is described in detail.
Bone sequestration following root canal therapy: a case report
Authors: PRICE J. D.
Published: September 2007

Summary. The unusual occurrence of the spontaneous shedding of a bony sequestrum following conventional root canal therapy of an upper lateral incisor is reported. A possible sequence of events is discussed.
External root resorption: its implication in dental traumatology, paedodontics, periodontics, orthodontics and endodontics
Authors: ANDREASEN J. O.
Published: September 2007

Summary. The aetiology and pathogenesis of three types of root resorption—surface, inflammatory and replacement—are reviewed, and their occurrence after certain types of orthodontic, periodontal, paedodontic and endodontic treatment is described.
Leakage evaluation in vitro of the root canal sealer cement Sealapex
Authors: HOVLAND ERIC J. , DUMSHA THOMAS C.
Published: September 2007

Summary. Sealapex was compared with two other root canal sealers for leakage in gutta‐percha filled extracted teeth using a silver stain technique. The extent of leakage in vitro in the root canal systems over a 30‐day period between the three root canal sealers was not statistically different. However, each sealer group leaked significantly less than the control group filled with gutta‐percha only. The results support previous findings that a sealer with gutta‐percha prevents apical leakage of the root canal system.
Antibacterial activity in paper points for endodontic therapy
Authors: RAWLE L. , ADAMS D. , WITHERLEY J.
Published: September 2007

Summary. Endodontic paper points were tested for antibacterial activity after the accidental finding: that bacterial cultures were inhibited by one variety. Of five types tested, two, from the same supplier, were found to exhibit diffusible antibacterial activity against salivary and subgingival plaque micro‐organisms. The identity of the agent responsible for this activity has not been determined, but preliminary tests indicate that it is an aldehyde.
The effects in vitro of zinc released from dental restorative materials
Authors: MERYON SYLVIA D. , JAKEMAN KENNETH J.
Published: September 2007

Summary. Zinc at the levels released from several dental restorative materials was toxic to both fibre‐blasts and macrophages, and so appears to be an important factor in the cytotoxicity in vitro of these materials. The toxicity of zinc to fibroblasts was less at high and low pH, but alterations in pH caused a substantial reduction in cell numbers, accompanied by alterations in cell membrane permeability. With macrophages, zinc had a significant effect at all pH values tested and there was little alteration in cell numbers with pH. No evidence was found for the role of zinc in stabilizing either cell or lysosomal membranes. However, as in vivo zinc is readily adsorbed by dentine, it is unlikely to cause toxic effects.
Measurements of the root surface temperature during thermo‐mechanical root canal filling in vitro
Authors: FORS U. , JONASSON E. , BERGQUIST A. , BERG J.‐O.
Published: September 2007

Summary. The temperature rise at the root surface during thermo‐mechanical root canal obturation was studied in vitro in 15 human teeth. The mean temperature elevation at a point 5 mm coronal to the apex was found to be 35°C. The impact of the results on the periodontal tissues during conditions in vivo are discussed.
Cervical external root resorption following trauma—a case report
Authors: MOULE ALEXANDER J. , THOMAS ROBYN P.
Published: September 2007

Summary. A case is presented in which cervical external root resorption occurred 3 years after trauma. Poor soft tissue management at the time of initial treatment is considered to have contributed significantly to the development of the lesion.
Surgical endodontic retreatment
Authors: REIT C. , HIRSCH J.
Published: September 2007

Summary. In teeth with periapical lesions and defective root canal seals non‐surgical retretment is usually preferred. Sometimes, howeve, such treatment may not be feasible and periapical surgery must be performed. The present study investigated a technique of retrograde root canal treatment as an alternative to the more conventional types of surgical procedure. The material consisted of 35 teeth whose root canals contained posts. In 77 percent of the cases it was possible to instrument and obturate the root canal up to the post. Following treatment the periapical tissues, as evaluated clinically and radiographically, showed evidence of having healed in 71 per cent of cases.
Healing sequence in capped inflamed dental pulps of Rhesus monkeys (Macaca mulatta)
Authors: COX C. F. , BERGENHOLTZ G.
Published: September 2007

Summary. Buccal class V cavities were prepared in 35 teeth of five adult Rhesus monkeys. Pulpal exposures were left open to the oral microflora for 24 hours. Twenty‐eight teeth were pulp‐capped with a hard setting Ca(OH)2 medicament and restored with amalgam. Pulpal responses were observed after 24 hours (non‐restored), 3, 5, 10 and 14 days. The pulps of teeth capped 3 days previously were dominated by polymorphonuclear leucocytes at the exposure site. Five‐day pulp‐capped teeth showed clot resolution, areas of necrosis and disintegrating polymorphonuclear leucocytes. Some pulps showed reorganization and stratification of fibroblasts adjacent to the medicament interface. Ten‐day pulp‐capped teeth showed dentine matrix mineralization directly adjacent to some portion of the medicament interface. Fourteen‐day pulp‐capped teeth showed complete soft‐tissue reorganization and new hardtissue formation. This study demonstrates that complete pulp healing and new hard‐tissue deposition will occur within 14 days, following an acute inflammatory lesion in monkeys.
The effects of two temporary crown materials on the dental pulp of monkeys (Macaca fascicularis)
Authors: PEARSON G. J. , PICTON D. C. A. , BRADEN M. , LONGMAN CATHERINE
Published: September 2007

Summary. A method for testing the pulpal response to temporary crown and bridge materials is described. The histological evaluation shows that neither test nor control material produced pulpal irritation over periods up to 4 weeks.
Thermomechanical compaction of gutta‐percha. II. A comparison with lateral condensation in curved root canals
Authors: KERSTEN H.W. , FRANSMAN R. , VAN VELZEN S.K. THODEN
Published: September 2007

Summary. Thermomechanical compaction was compared with lateral condensation by the use of radiographic examination and stereomicroscopic evaluation of transverse root sections for dye penetration etration and for adaptation of gutta‐percha. One hundred and twelve extracted single‐rooted teeth with curved root canals which were either round or oval to ribbon‐shaped in transverse sections were used. Under the condtions of this experiment performed in vitro, thermomechanical compaction proved to be significantly superior to laterl condensation on the aspects of radiographic appearance and the stereomicroscopic adaptation and compaction. With dye penetration no significant difference was found. Thermomechanical compaction resulted in better filling than lateral condensation, especially in the case of widely prepared oval or ribbon‐shaped root canals.
The response of caries‐free, unfilled teeth to electrical excitation: a comparison of two new pulp testers
Authors: DUMMER P.M.H. , TANNER M.
Published: September 2007

Summary. A total of 845 sound teeth in 54 patients were stimulated by one of two new electric pulp testers to obtain pain perception threshold values. The age range of the patients was 18 to 27 years and only incisor, canine and premolar teeth were studied. Both testers were found to produce threshold responses over a wide range of control settings in groups of similar teeth. From the results it is clear that there is no consistent threshold excitation value for teeth with intact‐uninflamed pulps.
Comparative sealing ability of temporary filling materials evaluated by leakage of radiosodium
Authors: FRIEDMAN S. , SHANI J. , STABHOLZ A. , KAPLAWI J.
Published: September 2007

Summary. The sealing ability of four temporary filling materials was evaluated in vitro, by studying leakage of radiosodium from the pulp chambers of teeth into an external medium. Zinc oxide‐eugenol based materials (IRM, ZOE) sealed better than calcium‐sulphate based materials (Cavidentin, Cavit‐G). Statistically significant differences were established between the sealing ability of the two types of materials during most of the experimental period, but no differences were established between the sealing ability of the two materials of the same type.
Tooth lengths in Nigerians
Authors: OKPO HILARY E.A. , AKPATA E.S.
Published: September 2007

Summary. The lengths of maxillary and mandibular teeth with complete apices extracted from Nigerians were measured on graph paper callibrated in millimetre squares. The mean lengths obtained closely approximated to those in previous studies, and therefore did not support the view that Africans have longer teeth than Caucasians.
Biological evaluation of glass ionomer cements
Authors: ÜÇOK M.
Published: September 2007

Summary. Sixty human premolar and canine teeth were used in this study. Class V cavities were prepared with a turbine handpiece. The experimental material was ASPA, with silicate cement and zinc oxide‐eugenol cements being used as controls. The teeth were extracted approximately 4 days, 30 days or 90 days after insertion of the filling material. They were demineralized and prepared for histological examination. The test procedure and evaluation closely followed recommendations by the FDI (1980). The reaction at the short time interval for each material was similar, while at the intermediate and long periods silicate cement caused the most inflammation, zinc oxideeugenol cement the least, and ASPA an intermediate response. The reaction to ASPA was reduced at the long period compared with the intermediate period.
Investigation of the cdytotoxicity of bacterial species implicated in pulpal inflammation
Authors: MERYON SALVIA D. , JAKEMAN K. J. , BROWNE R. M.
Published: September 2007

Summary. The major bacterial species in ferret plaque were indetified and the cytontoxicity of selected orginsisms in vitro assessed to determine their porential role in pulpal inflammation. Of the five species investigated in detail the cell fractions of Escherichia coli and Streptococcus sanguis from anaerobic cultures. The release of a lysosomal enzyme was elicited to differing degree by all five bacterial species. While the amount of enzyme released from macrophages was greater, fibroblasts were generally more sensitive, with the media fraction in addition to the cellular fraction affecting cell numbers and enzyme release. The action of S. faecalis on both cell types was shown to be dose‐department. Since the number of bacteria involved in vivo is small these results suggest they would have little direct toxic effect indicating that some other mechanism must be invoved.
Radiographic appearance of artificially prepared periapical lesions confined to cancellous bone
Authors: LEE S.‐J. , MESSER H. H.
Published: September 2007

Summary. Twenty artificial periapical lesions confined to cancellous bone were prepared at the apices of first and second mandibular molars of human cadavers. The lesions emphasized removal of the lamina dura and preparation of a ‘halo’ lesion surrounding the root apex, plus the addition of a simulated sclerotic border. Radiographs taken before and after creation of the lesions were scored by three examiners for detectable lesions Cross‐sections of the lesions were assessed for the extent of bone destruction. Periapical lesions confined to cancellous bone were detected in 80 per cent of cases, and the presence of a sclerotic border tended to enhance visualization, although not in all cases. Intentional cortical involvement also improved detection of lesions. The anatomical features of the periapical area appear to promote the visualization of lesions which might not be detected in other locations.
Effect of implantaton of AH26 silver‐free in subcutaneous tissue of guinea‐pigs
Authors: TAGGER M. , TAGGER ETTY
Published: September 2007

Summary. Twenty‐five polyethylene tubes filled with AH26 sealer, regular or silver‐free, were implanted subcutaneously in the backs of seven young guinea‐pigs. The tissue reactions were studied after 2 months and evaluated for the amount of inflammation and fibrosis present at the openings of the tubes. The differences between the two sealers were minor.

In almost one‐half of the specimens, some sealer was present outside the tubes and the reaction around these clumps was more severe than at the openings of the tubes. In this respect, the trend of a stronger reaction to AH26 with silver was more noticeable.

The reduced dentine‐staining potential of the silver‐free sealer, combined with its slightly smaller irritational potential, should make it preferable to the regular one if its physical properties are not inferior.
A comparative pulpal study of two dental amalgam alloys
Authors: TOBIAS R. S. , PLANT C. G. , BROWNE R. M.
Published: September 2007

Summary. Pulpal responses to a conventional amalgam, New True Dentalloy, and a high copper amalgam, Solila Nova, were studied over a period of 6 months. Kalzinol was used as a negative control material. Standardized Class V cavities were prepared in the canine teeth of male ferrets under ketamine/xylazine anaesthesia. The animals were killed with excess pentobarbitone and the teeth extracted after 7, 14, 28 and 183 days. After processing, the teeth were serially sectioned and assessed qualitatively and quantitatively according to standard criteria. There were some variations in the pulpal responses at 7 days and 14 days post‐operatively but at 28 days and 183 days, the responses under the two materials were similar with only slight pulpal inflammation being observed. No pulpal inflammation was present beneath surface‐sealed Solila Nova cavities. Gram positive micro‐organisms were observed at the interface of cavity wall and material in conventional cavities but not within those surface‐sealed with Kalzinol.
Apical displacement of a gutta‐percha cone on cementation of a post and core
Authors: LUI J. L.
Published: September 2007

Summary. A case is reported where the root canals of were filled with apical gutta‐percha cones and AH26 sealer. Two months later the was prepared for a post crown, and on cementation of the post the root filling was displaced apically. The tooth gave symptoms until apicetomy and retrograde root filling were carried out.
Maxillary first molar accessory root. A case report
Authors: TIDMARSH B. G.
Published: September 2007

Summary. A case is presented in which resection of the mesiobuccal root of a maxillary first molar revealed the presence of an additional root on the mesial aspect. The occurence of such a root is considered to be rare.
The response of the dental pulp to mechanical exposure in gnotobiotic rats mono‐infected with a strain of Streptococcus mutans
Authors: PATERSON R. C. , POUNTNEY S. K.
Published: September 2007

Summary. The maxillary molar pulps of gnotobiotic rats mono‐infected with a strain of Streptococcus mutans and maintained on a high sugar diet, were mechanically exposed and left open to the oral environment. No evidence of inflammatory cell infiltration of pulp tissue apart from superficial cells was observed. Seven days after pulpal exposure, necrosis was detected in the superficial layers of the pulp. After 28 days, the necrosis was more extensive, and repair, manifested by dentine bridge formation, was observed in only a limited number of teeth. The lack of inflammation and slow progress of necrosis in pulps left open to the oral cavity appeared to indicate that the test strain of Streptococcus mutans had limited pathogenicity to the pulp. These observations provide support for the practice of indirect pulp capping in deep carious lesions.
Effect of calcium hydroxide treated dentine on pulpal responses
Authors: WARFVINGE J. , ROZELL B. , HEDSTRöM K.‐G.
Published: September 2007

Summary. The purpose of the present study was to test the hypotheses that calcium hydroxide enhances pulpal protection against irritating substances in and around dental restorations when topically applied to cut dentine, and to acquire further information regarding the possible mechanisms involved. Cavities in dentine were treated for 30 days with either a water slurry of calcium hydroxide or a hard‐setting calcium hydroxide containing base. Control cavities were treated with saline. The additional effect of dry cutting prior to the restoration was also included as a control. Pulpal responses after placement of a silicate cement restoration were evaluated after an additional period of 30 or 150 days. From histological sections the volumes of inflamed pulp and the volumes of irregular secondary dentine were calculated with a morphometric method of evaluation. Changes in dentine to the calcium hydroxide treatment were observed with scanning electron microscopy. Most pulps in teeth with cavities treated with saline and restored for 30 days with silicate cement exhibited inflammatory alterations. Calcium hydroxide treated teeth had a significantly lower volume of inflamed pulp compared with the saline controls. Dry preparation was also associated with reduced inflammatory reaction. Pulps in teeth with dentine treated by the calcium hydroxide containing hard‐ setting base displayed the same magnitude of pulpal inflammation as the saline treated controls. After restoration for 150 days the volumes of inflamed pulp tissue were reduced in all treatment groups, however the least pulpal responses were found in teeth treated with calcium hydroxide slurry. Data also showed that the calcium hydroxide treatment was associated with only small volumes of irregular secondary dentine, while in contrast dry cut teeth showed large volumes of irregular secondary dentine. Scanning electron microscopic evaluation of dentine treated with calcium hydroxide revealed reticular structures inside the dentinal tubules
An investigation into the bond strength between a root canal sealer and root‐filling points
Authors: JEFFREY I. W. M. , SAUNDERS W. P.
Published: September 2007

Summary. It is essential that a competent bond should exist between the gutta‐percha point used to obturate a prepared root canal and the scaler cement, in order to avoid the risks of both periapical leakage and possible disruption of the point during preparation of the tooth for a post crown. An experimental method was established whereby disruption between the two media could be examined. Shear tests were carried out using both smooth surfaced and sandblasted gutta‐percha points, and comparisons in their bond strengths were made. Statistical analysis showed that roughening the gutta‐percha points significantly improved the bond strength between point and sealer.
The influence of the smear layer on the sealing ability of canal obturation
Authors: CERGNEUX M. , CIUCCHI B. , DIETSCHI J. M. , HOLZ J.
Published: September 2007

Summary. The sealing of obturated root canals which had previously been cleaned chemically by EDTA or mechanically by ultrasound was compared using 60 single‐rooted teeth in an in vitro study. At first, the canals were manually prepared under copious irrigation with NaOCl. Then the specimens were divided into three experimental groups: in group I (control group) the canals were immediately obturated without further preparation; in group II (ultrasound group) the canals were subjected to ultrasound before being obturated, and in group III (EDTA group) the canals were irrigated with EDTA before being obturated. All speciments were then subjected to dye infiltration before being transversely sectioned at various levels from the apex. The amount of leakage was scored on an arbitrary four‐point scale. The results showed some differences in leakage between the three groups at levels close to the apex: EDTA‐treated canals showed the least infiltration, while those treated with ultrasound showed significantly less compared with the control group. The role of the smear layer and its removal is discussed in the light of these results.
The effect of standard or serial preparation on single cone obturations
Authors: BEATTY R. G.
Published: September 2007

Summary. This leakage study, in vitro, used methylene blue dye as a marker to detect the extent of apical fluid penetration after buccal roots from maxillary first bicuspids were instrumented either by the standard technique or serially, and obturated with laterally condensed gutta‐percha and sealer, a single gutta‐percha master cone and sealer, or sealer alone. The linear extent of dye penetration was measured after the roots were split longitudinally. In this study the laterally condensed gutta‐percha and sealer technique resulted in the least apical penetration of dye. The single gutta‐percha cone and sealer technique groups had less dye penetration than the groups where obturation was with sealer alone. The use of the standard or serial technique of preparing canals resulted in no significant difference in the quality of obturation using a single gutta‐percha cone with sealer or using sealer alone.
Scanning electron microscpe study comparing the effecacy of endodontic irrigating systems
Authors: ALAÇAM T.
Published: September 2007

Summary. Thirty‐five single rooted teeth were biomechanically instrumented with salaine, following' which they were subjected to different methods of irrigation. Four groups of teeth were irrigatied using and Endomate unit with NaOCl in combination with H2O2, or EDTA, or glutaraldehde or saline.

Two groups were irrigated with 5 per cent NaOCl in combination with ultrasound; one of them was further irrigated with 3 per cent H2O2 using the Endomate system.

The control group was irrigated with NaOCl and H2O2 using the conventional technique. The prepared root canals were examined for the presence of smear layer under SEM.

All groups irrigated with the ultrasonic technique and the group irrigated with the endomate system using EDTA solution showed significantly cleaner surfaces; the smear layer was also greatly reduced.
Separating instrument technique for root canal filling: a case report
Authors: TAMSE A. , KATZ A.
Published: September 2007

Summary. When no accepted method of canal sealing is possible in narrow curved cancals, intentionally separating stainless steel files in the canal can be considered. A case is presented in which this method was applied in aseverely curved mesial root of a lower second molare with a 4‐year follow‐up. The advantages and disadvantages of this method are discussed.
Root resorption in autotransplanted maxillary canine teeth
Authors: EDMUNDS D. H. , BECK C.
Published: September 2007

Summary. The results of the endodontic management of root rsorption in 77 transplanted teetharedescribed. Apical bny radiolucelncy healed in 75 per cent of cases but the prognosis for root resorption was poorer; in only 34 per cent of cases was the resorption arrested. Various factors which might have influendced the outcome of treatment are discussed
The effects of hand, sonic and ultrasonic instrumentation on the shape of curved root canals
Authors: TANG M. P. F. , STOCK C. J. R.
Published: September 2007

Summary. This study compared the effects of hand, sonic and ultrasonic instrumentation on the shape of curved root canals in 60 extracted human lateral incisors and premolars. Each root of moderate or severe canal curvature was mounted onto a simulated crown and filled with a radiocontrast medium. Enlarged photographic prints obtained from radiographs taken before and after root canal preparation were measured. The results indicated a lower incidence of apical zip and elbow formation in the ultrasonic preparations when compared with those prepared by hand and sonic, irrespective of the canal curvature. A more prominent hour‐glass shape was prepared by hand and sonic instruments particularly in severely curved root canals. A distinctive taper was produced by each method of preparation. All three instrumentation techniques showed preferential dentine removal from the convex aspect of the canal in the apical portion and the concave aspect in the middle portion of the root canal.
The heat generated on the external root surface during post space preparation
Authors: SAUNDERS E. M. , SAUNDERS W. P.
Published: September 2007

Summary. The heat generated on the external root surface of human premolar teeth during post space preparation was measured in vitro. The rise in temperature was recorded at a point 6 mm from the apex of the tooth using a thermocouple attached to a chart recorder. The temperature rise was greatest when the removal of gutta‐percha was combined with post channel preparation. Temperature rises of up to 31°C were recorded. Instruments that only removed gutta‐percha did not generate the same amount of heat.

The results from this study suggest that the use of engine‐driven drills to prepare post channels in teeth may generate temperature rises that may cause periradicular tissue damage, and caution should be exercised during their use.
An in vitro comparison of ultrasonic and conventional methods of irrigant replacement
Authors: DRUTTMAN A. C. S. , STOCK C. J. R.
Published: September 2007

Summary. The effectiveness of irrigant replacement in fine canals was compared using three sizes of irrigating needle and an ultrasonic method. The result showed that irrigant replacement became progressively less effective towards the apex regardless of the method of irrigation or needle size. With conventional methods, irrigation performance varied with the size of needle and volume of irrigant. With the ultrasonic method results depended on irrigation time, but was independent of irrigant flow rate through the handpiece, the size of the canal or the file size.
Dens invaginatus with an open apex: a case report
Authors: MORFIS A.S. , LENTZARI A.
Published: September 2007

Summary. A severe case of dens invaginatus is described on an upper central incisor that was associated with a discharging sinus tract. The outer pulp chamber contained vital tissue while the inner one contained necrotic material. Root canal treatment was carried out with long‐term calcium hydroxide dressings to induce apical closure. The canal system was subsequently filled and the tooth followed up for 4 years.
Effect of disinfection on number and stainability of Gram‐positive bacteria
Authors: VAN MULLEM P.J. , WIJNEERGEN M.
Published: September 2007

Summary. Evidence provided by the Brown and Hrenn stain for the presence of bacteria in fixed tissue sections depends on the ability to demonstrate them by staining. Previously, in a model experiment, it has been shown that demineralizing agents reduce the number of blue‐staining Gram‐positive bacteria (Wijnbergen & Van Mullem 1987). In the present study the influence of a structure‐destroying disinfectant, a structure‐preserving disinfectant or heat disinfection on number and stainability was investigated using S. faecalis suspensions. Numbers were determined using a haemocytometer, and percentages of blue‐staining organisms were ascertained from smears. Immediately after disinfection the relative number of Gram‐positive staining bacteria was reduced by a factor of three for chlorhexidine, almost two for alcoformol, and was slightly reduced by heat. After 4 days of storage the reduction factors were 90, 4, and 2, respectively. After 14 days of storage the reduction factors were infinite, 30 and 5, respectively. These results were explained on the basis of the rate of cell wall destruction evoked by the respective agents.
Digital image analysis for the diagnosis of periapical bone lesions: a preliminary study
Authors: MOL A. , VANDER STELT P. F.
Published: September 2007

Summary. Digital image analysis techniques enable the problem of examiner variability to be circumvented, and can be used to develop quantitative descriptions of bone lesions. This study investigated a method for describing periapical bone lesions.

An edge‐detection technique was developed for application to routine periapical radiographs. Most periapical bone lesions appear radiographically as dark areas compared with the surrounding tissues. The digital imaging process resulted in an outline resembling the contour of the image of the lesion present. This contour could be successfully projected on to the original image with only limited operator assistance.

Processing of the image resulted in increased definition of the structures present, with considerable noise reduction. The result was a simplified diagnostic examination process that promised a high degree of objectivity in periapical bone lesion detection.

It is concluded that the results encourage further development of image processing techniques suitable for the definitive detection and diagnosis of periapical bone lesions.
Microbiological evaluation of the Hygenic Ultrafil heated gutta‐percha delivery system
Authors: GLICKMAN G. N. , WINFORD T. E. , GUTMANN J. L.
Published: September 2007

Summary. The Ultrafil heated gutta‐percha delivery system was evaluated to determine if (i) the prepackaged gutta‐percha used in the system was contaminated and antimicrobial, (ii) the gutta‐percha‐containing cannules were packaged in a sterile state, and (iii) a combination of alcohol soak and low heat was sufficient to eliminate any contaminating microbes. The results showed that although the gutta‐percha did not appear to be contaminated with cultivable bacteria, the cannules were contaminated with micro‐organisms that could not be totally eliminated by alcohol soak and low heat. Suggestions for the maintenance of clinical asepsis when using this technique are provided.
Bactericidal effects of human neutrophils and sera on selected endodotic pathogenic bacteria in an anaerobic environment
Authors: WU M. K , HENRY C. A. , GUTMANN J. L.
Published: September 2007

Summary. Phagocytosis by normal human neutrophils and the bactericidal activity of normal human pooled serum were measured under anaerobic conditions on six endodontic pathogenic bacterial species from the genera Actmomyces, Bacteroides, Fusobacterium, Peptostreptococcus and Streptococcus. The results revealed that Actinomyces viscosus was not killed either by human neutrophils or by 20 per cent serum; Peptostreptococcus anaerobius was not killed by either 20 per cent or 95 per cent serum; and Bacteroides intermedius was susceptible to both 20 per cent and 95 per cent serum, but was not killed by neutrophils after exposure for 20 minutes. The other species showed intermediate susceptibility patterns. Such results suggest that oral pathogens vary with regard to the bactericidal effects of these two host defence mechanisms, and that this variation may at least in part explain the relative quantities of microbes recovered in certain oral infections.
Penetration of dentine by three oral bacteria in vitro and their associated cytotoxicity
Authors: MERYON S. D. , BROOK A. M.
Published: September 2007

Summary. Three common oral bacteria, namely Streptococcus sanguis. Actinomyces viscosus and Curynebacterium spp, were studied with regard to their ability to penetrate etched and unetched dentine and for their effect on underlying cell cultures. The test organisms were grown in cylinders above dentine slices 100 and 500 μm thick for 72 hours. The slices were in contact with tissue culture medium covering a layer of fibroblasts. Penetration of 100 μm slices was most rapid with 5. sanguis, followed by A. viscosus and Corynebacterium. The pattern was similar but slightly delayed when 500 μm slices were used, but in most cases penetration had occurred by 72 hours. The presence of a smear layer had no effect on the results obtained. Following penetration, cell destruction was most extensive with S. sanguis, the most cytotoxic organism, followed by Corynebacterium and A. viscosus. In the limited number of dishes where no penetration occurred there was little effect on cell numbers.
Adhesion of root canal sealers to bovine dentine and gutta‐percha
Authors: WENNBER A. , NIOM D. ØRSTAVIK
Published: September 2007

Summary. The adhesive properties of eight root canal sealers, applied as a thin layer between a dentine and a gutta‐percha surface, were investigated. Tensile bond strengths ranged from 0.02 MPa (Sealapex) to 2.38 MPa (AH26). Inspection of fractured surfaces indicated failure of adhesion to dentine (Tubli‐Seal) and to gutta‐percha (AH26, Diaket) as well as failure of cohesion (CRCS, Kloroperka N‐Ø, ProcoSol, rosin chloroform, Sealapex). Pretreatment of the dentine surface with EDTA caused a significant increase in bond strength for ProcoSol, rosin chloroform, Sealapex, and Tubli‐Seal.
Predominant obligate anaerobes invading the deep layers of root canal dentine
Authors: ANDO N. , HOSHINO E.
Published: September 2007

Summary. This study was carried out to investigate the presence and types of bacteria invading the deep layers (0.5–2.0 mm from the surface of the root canal wall) of infected dentine of human root canals by sampling with an anaerobic glove box system the split surfaces of eight freshly extracted teeth. More bacteria were recovered after incubation in an anaerobic glove box than after aerobic incubation in air with 30 per cent CO2. Out of 256predominant bacteria isolated, 205 isolates (80 per cent)were bligate anaerobes. These findings suggest that the environment of deep layers of endodontic dentmal lesions is anaerobic and favours the growth of anaerobes. Among the obligate anaerobic isolates, strains belonging to Lacto‐bacillus (30 per cent) and Streptococcus (13 per cent) were predominant, followed by Propionitacterium (9 per cent). No strains of obligate anaerobic Gram‐negative rods were isolated. The tnicroflora of deep layers of infected root dentine is somewhat similar to that of the deep layers of carious lesions in coronal dentine.
Root canal anatomy of mandibular second molars. Part I
Authors: MANNING S. A.
Published: September 2007

Summary. The root canal anatomy of 149 mandibular second molars was studied using a technique in which the pulp was removed, the canai space filled with black ink and the roots demineralized and made transparent. Of the 149 teeth, 22 per cent had single roots, 76 per cent had two roots and 2 per cent had three roots. In the single‐rooted teeth, three canals were most common, while in the mesial root of the two‐rooted teeth, two canals that joined near the apex and one canai in the distal root were most frequent. Round canals were most common in two‐rooted teeth and C‐shaped canals in single‐rooted teeth. Transverse anastomoses were found in 33 per cent of roots, most commonly in the middle third of the root. Lateral canals were found in 72 per cent of roots, most commonly in the apical third of the root. The apical foramen was positioned at the apex in only 33 per cent of roots, and apical deltas were found in 35 per cent.

The patient's age and race affected canal shape, with more round canals present in patients over 35 years of age, and more C‐shaped canals in Asians. The sex of the patient and the side of the mouth affected the presence of apical deltas, with more being found in males and on the left side. Single‐rooted teeth had more complex root canal systems than two‐rooted teeth, with more lateral canals, transverse anastomoses, apical deltas and C‐shaped canals.
Periapical tissue reaction to root fillings with Sealapex
Authors: SONAT B. , DALAT D. , GüNHAN O.
Published: September 2007

Summary. The histological response of periapical tissues to root canal fillings with Sealapex, pure calcium hydroxide and gutta‐percha points was studied in dogs' teeth. After putpal extirpation the root canals were enlarged, irrigated and dried. Teeth in the first group were filled with gutta‐percha points alone, those in the second group were filled with pure calcium hydroxide and gutta‐percha, and those in the third group were filled with Sealapex and gutta‐percha. The animals were killed after 7, 30 and 90 days and histological sections of each specimen were prepared. It was concluded that hard tissue formation was more pronounced after root filling with Sealapex than with calcium hydroxide or gutta‐percha points.
Effect of gloves on tactile discrimination using an endodontic model
Authors: CHANDLER N. P. , BLOXHAM G. P.
Published: September 2007

Summary. This study used as endodontioc model to investigate the effect of glove wearing on tactile sensitivity. Dental students, all of wham had worn gloves throughout their clinical training, used a file to detect resistance at the apical end of an endodontic teaching aid. Wearing gloves produced a statistically significant reduction in tactile sensitivity. As large intra‐ and inter‐subject variations were observed both with and without gloves, the sensitivity change brought about by the wearing of the latter seems unlikely to be of significance in clinical endodontic.
Evaluation of sealing properties of 70°C thermoplasticized gutta‐percha used as a retrograde root filling
Authors: WOO Y. R. , WASSELL R. W. , FOREMAN P. C.
Published: September 2007

Summary. The efficacy of low temperature (70°C) thermoplasticized gutta‐percha used to seal root canals by the retrograde approach following apicectomy was assessed. A dye leakage technique was used, and gutta‐percha was compared with amalgam. Two groups of different sized roots were apicected, and their root canals instrumented and filled conventionally with laterally condensed gutta‐percha. Each group was randomly divided into four sub‐groups; one was the control group in which no further treatment was carried out. In the other three groups the apical 3 mm of gurta—percha was removed, and the apical cavities filled as follows: group I with 70°C thermoplasticized gutta‐percha with sealer; group II with 70°C thermoplasticized gutta‐percha without seaier; group III with amalgam. The roots were rendered transparent by acid demineralization, and maximum dye penetration was measured. The results showed statistically significant ranking of leakage between the four sub‐groups: 70°C thermoplasticized gutta‐percha with sealer 70°C thermoplasticized gutta‐percha without sealer amalgam control. The larger canals in all four sub‐groups also exhibited significantly greater leakage than the smaller ones.
Tissue response to glass ionomer retrograde root fillings
Authors: FORD T. R. PITT , ROBERTS G. J.
Published: September 2007

Summary. The periapical tissue response to glass ionomer cement retrograde root fillings was investigated both in the presence and in the absence of fillings in the root canals of eight upper incisor teeth of four monkeys. The pulps of the teeth were extirpated and one canal in each pair was filled with laterally condensed gutta‐percha immediately after canal preparation. The other canal was prepared but left open to oral contamination. Apicectomies were performed on both teeth in each pair 1 week later, and glass ionomer cement retrograde root fillings were placed. After 5 months, the teeth and surrounding tissues were removed and prepared for histological examination.

All four of the teeth without root canal fillings showed severe periapical inflammation, and bacteria were present in the interface between the dentine and the retrograde root filling. The teeth with root canal fillings showed or no periapical inflammation.

This study showed that adhesive retrograde root fillings were successful when the root canal was completely filled, but in the absence of a guttapercha canal filling they failed to provide a seal.
An investigation into the apical leakage of root‐filled teeth prepared for a post crown
Authors: EWART A. , SAUNDERS W. P.
Published: September 2007

Summary. The effect of post canal preparation on the apical seal of endodonticaily treated teeth was studied in vitro. Single‐rooted teeth with mature apices were prepared chemomechinically and obturated with gutta‐percha and sealer using one of four techniques: cold lateral condensation, thermo‐mechanical compaction, thermomechanical compaction as an adjunct to lateral condensation (hybrid technique), or lateral condensation using an electrically heated spreader, the Endotec. Forty‐eight hours after obturation each group of 15 teeth was prepared to accept a post crown. Five teeth in each group were left unprepared as controls. The extent of apical leakage was then determined using a dye, Indian ink, and a clearing technique that rendered the teeth transparent. Linear measurement of the dye penetration was recorded. The results showed that, for each method of obturation, there were no statistically significant differences between the teeth prepared for a post and the unprepared controls. There were no significant differences in leakage between the different groups that had been prepared for a post, or between the control groups.
Extensive bone loss associated with periapical infection with Bacteroides gingivalis: a case report
Authors: SJÖGREN U. , HÄNSTRÖM L. , HAPPONEN R. P. , SUNDQVIST G.
Published: September 2007

Summary. A case is presented in which rapid and extensive bone loss occurred around a maxillary molar with periapical infection by Bacleroides gingivalis (Ptrphyrmaonas gingivalis). The lesion failed to respond to conventional endodontic therapy. An adjacent vital molar was extracted and an unfavourable periodonta) condition occurred despite microbiological investigation and surgery.
The effects on the dental pulp of a composite resin and two dentine bonding agents and associated bacterial microleakage
Authors: GRIEVE A. R. , ALANI A. , SAUNDERS W. P.
Published: September 2007

Summary. The pulpat reaction associated with a composite resin alone and composite resin used in conjunction with two dentine bonding agents was studied. Class V cavities were prepared on the labial surfaces of the canine teeth of 18 male ferrets. After acid etching of the enamel margins, the cavities were restored with either a composite resin alone or in combination with one of two dentine bonding agents, Scotchbond and Gluma. One cavity in each animal was filled with Kalzinol as a control. The animals were killed after 7, 14 and 28 days. After histoiogicat processing, the pulpal changes were assessed qualitatively and quantitatively according to standard criteria.

There were variations in the pulpal response at all time intervals. The responses to the two dentine bonding agents were similar to those found with composite resin alone. No pulpal inflammation was observed in the control teeth. Gram‐positive micro‐organisms were identified at the interface of restoration and cavity wall, or within the dentinal tubules in virtually all cases in which pulpal inflammation was observed.
Organizing a postgraduate course
Authors: STOCK C. J. R.
Published: September 2007

Summary. The running of a section 63 hands‐on course on endodontics requires prior planning. Suggestions on how to plan such courses include the design of the programme, the number of course members and instructors, requirements from the postgraduate centre, equipment and materials needed, travel and accommodation, and finally reimbursement.
British Endodontic Society proposals for recruitment of instructors for ‘hands‐on’ courses for general dental practitioners
Authors: HOSKINSON A. E.
Published: September 2007

Summary. This paper addresses the problem of the insufficient number of instructors available for ‘hands‐on’ endodontic courses for dental practitioners throughout the UK. The Council of the British Endodontic Society proposes the setting up of regional endodontic study clubs. Subsequently, some study club members will be encouraged to present ‘hands‐on’ courses to other practitioners in their region. It is hoped that Area Representatives of the Council, who will organize the study clubs, will be found among the university teachers of endodontics.
Establishing a postgraduate course in endodontics
Authors: FORD T. R. PITT
Published: September 2007

Summary. A proposal was first made to the University of London in 1985 to establish an MSc degree in Endodontics. It was finally approved in 1988. The first course started in 1988, and is now offered by two schools of the University, the United Medical and Dental Schools of Guy's and St Thomas's Hospitals and the Institute of Dental Surgery. The course has three main components: a taught part, clinical practice and a research project. The taught part is a course common to both the schools, while clinical practice and the research are carried out at the students' respective schools.
Identification of alpha2 adrenoceptors in the blood vessels of the dental pulp
Authors: IBRICEVIC H. , HEYERAAS K. J. , JUHAS E. PASIC , HAMAMDZIC M. , DJORDJEVIC N. , KRNIC J.
Published: September 2007

Summary. Using selective agonists and antagonists of alpha, adrenoceptors, attempts were made to identify the subtype alphaj adrenoceptors in the blood vessels of the canine dental pulp. In chloralose‐anaesthetized dogs, intra‐arterial administration of noradrenaline and guanabenz in different doses produced a dose‐related pulpal vasoconstriction which was measured using hydrogen‐gas clearance. The vasoconstrictor response to noradrenaline was inhibited by phentolamine, a non‐selective alpha adrenoceptor antagonist. The response to guanabenz was inhibited by rauwoiscine, a highly selective alpha, adrenoceptor antagonist. The results demonstrated that alpha, adrenoceptors are present in the blood vessels of dog dental pulp.
Inherent variability in the power output of endosonic instruments
Authors: LUMLEY P. J. , WALMSLEY A. D.
Published: September 2007

Summary. The dispiacement amplitude of endosonic files was measured with the aid of light microscopy in order to determine the power output of different ultrasonic units. The results showed that there was a substantial difference in the displacement amplitudes when the same size of file was used in different ultrasonic units made by the same or different manufacturers. File fracture was found to be a problem when files were driven at high displacement amplitudes.