bluuebunny/crossref_metadata_2025 huggingface dataset:
Induction of heterotopic bone formation by demineralized dentin in guinea pigs: antigenicity of the dentin matrix
Authors: Bang Gisle
Published: April 2006

Abstract. Fifty autogenous, 120 allogenic and 40 xenogenic demineralized dentin specimens as‐well as 36 undemineralized allogenic specimens were implanted in the abdominal muscles of 74 male guinea pigs for periods ranging from 4 to 12 weeks. An experimental model for the first and second set reaction in allogenic ear skin grafts was established in 10 male guinea pigs. The mean survival times of the first and second sets of these grafts were 10.1 days, s.d. = 1.57 and 5.2 days, s.d. = 0.78, respectively. Repeated implantation of both undemineralized, and demineralized and lyophilized allogenic dentin evoked an immune response in the host resulting in an accelerated skin graft rejection. Furthermore, in the second and third sets of implants the bone inducing process was either prevented (undemineralized dentin) or reduced (demineralized and lyophilized dentin). Xenogenic demineralized dentin failed to induce osteogenesis, probably due to an intense host immune response. The first set of allogenic demineralized dentin implants, on the other hand, induced bone formation in a high percentage of cases, it even gave the impression of enhancing the induction process compared to autogenous dentin.
A study of Danish snuff‐induced oral leukoplakias
Authors: Roed‐Petersen B. , Pindborg J. J.
Published: April 2006

Abstract. In a sample of 450 patients with oral leukoplakias, 32 used snuff, which was a Danish wet variety, Göteborg snus ® (Gothenburg Snuff). The group of snuff users consisted of males only, with a mean age of 58.4 years. The mean life exposure time lo snuff was 197,000 hours, the equivalent of 22 years of constant use. Patients with leukoplakia due lo the use of snuff experienced fewer symptoms than did patients with leukoplakia due to other unknown causes. The snuff users also tended to be older at first examination, and to have a higher alcohol intake. Histological changes characteristic of snuff‐users' leukoplakias were: (1) vacuolated cells in the upper part of the spinous cell layers of the epithelium with intervening streaks of parakeratinized cells, (2) epithelial hyperplasia, and (3) hyalinized, eosinophilic deposits around salivary glands. However, statistically significant differences were not found between snuff‐induced leukoplakias and other leukoplakias either as lo dysplasia observed histologically or as to malignant development.
Hyaline bodies in odontogenic cysts: Electron microscopic observations
Authors: Jensen Jerald L. , Erickson John O.
Published: April 2006

Abstract. Hyaline bodies in odontogenic cysts were studied in the electron microscope after retrieval from paraffin blocks. Although epithelial preservation was poor, hyaline bodies appeared to be well preserved. Our observations do not support unequivocally either of the two major hypotheses of pathogenesis ‐ epithelial cell production or hematogenous origin. Electron micrographs do, however, clearly demonstrate that hyaline bodies are not composed of keratin. Hyaline bodies in our material reveal no ultrastructural similarity to the published electron micrographs of cuticle “B” which Listgarten (1966a, b) suggested corresponds to the secondary enamel cuticle.
Potential of yttrium‐aluminum‐garnet laser in caries prevention
Authors: Yamamoto H. , Ooya K.
Published: April 2006

Abstract. Intact tooth enamel of extracted human teeth was exposed to a pulsed Nd‐YAG laser at an energy density of 10 to 20 joules/cm2. In vitro demineralization by lactic acid was accomplished by dextran‐producing strains of Streptococcus mutatis PK‐1 growing on the enamel surface. Scanning electron microscopic observations on the laser irradiated enamel supported micro‐radiographic findings and indicated that the laser irradiated enamel surface was more resistant to decalcification than the non‐irradiated control enamel. Surface changes suggestive of fusion occurred at the low energy density of 10 to 20 joules/cm2. Laser beam irradiation imparted a degree of alteration to enamel surface that subsequently reduced subsurface demineralization. A significant difference in solubility was found between laser irradiated and non‐irradiated enamel.
The pathogenesis of odontogenic cysts: a review
Authors: Browne R. M.
Published: April 2006

The pathogenesis of the three common forms of odontogenic cyst is discussed. It is concluded that the dental cyst arises from proliferation of the epithelial rests of Malassez in a focus of inflammation stimulated by pulpal necrosis of the associated tooth. It enlarges by unicentric expansion from the hydrostatic pressure of its contents.

The dentigerous cyst arises from pooling of inflammatory exudate, which is derived from the obstructed follicular veins of an unerupted tooth and accumulates between the reduced enamel epithelium and the crown of the tooth. It enlarges by unicentric expansion from the hydrostatic pressure of its contents.

The odontogenic keratocyst arises by proliferation of the residues of the dental lamina, possibly as a hamartomatous abnormality. It enlarges by both multicentric expansion due to the proliferation of localized groups of epithelial cells in the lining and by unicentric expansion from the hydrostatic pressure of its contents.
The histology of prolonged candidal infection of the rat's tongue
Authors: Russell C. , Jones J. H.
Published: April 2006

Long‐term candidal infection of the rat's tongue has been found to produce marked epithelial hyperplasia with keratin trapped between the folds of hyperplastic epithelium. The epithelium showed atypia which did not amount to carcinoma in situ. Degenerative changes were found in the superficial layers of the lingual muscle beneath areas of candidal infection, and after a year, hyalinized fibrous tissue appeared to replace the damaged muscle.
Ultrastructure of the oral epithelium in leukoplakia associated with tylosis and esophageal carcinoma
Authors: Tyldesley W. R. , Kempson Susan A.
Published: April 2006

Abstract. Ultrastructural studies have been carried out on epithelium taken from the oral lesions of tylosis‐related leukoplakia and preleukoplakia in a group of patients known to be at high risk for esophageal carcinoma. Several structural abnormalities are described; in particular, the presence of intranuclear electron dense particles 90 nm in diameter. Similar particles have been found in the nuclei of epithelial cells from an esophageal carcinoma developing in one of the patients under study.
Lanthanum staining of cell surface and junctional complexes in normal and malignant human oral mucosa
Authors: Palekar Malini S. , Sirsat Satyavati M.
Published: April 2006

Abstract. Biopsies from normal and malignant human oral epithelium were studied electron histochemically using lanthanum nitrate for a selective demonstration of junctional complexes at the plasma membrane of adjacent cells. The heavy metal complex was found to settle irregularly, sometimes in intimate proximity to the epithelial cell, in areas corresponding to the glycocalyx, gap junctions, desmosomes and nonspecific contact areas. Tight junctions were rarely seen. The lack of these morphological adhesive areas, the desmosomal detachment seen between cancer cells and the increased lanthanum‐positive cell surface may be possible factors responsible for the dissociation of oral malignant cells.
Changes in the Fine Structure of the Human Dental Pulp Subsequent to Carious Exposure
Authors: Torneck Calvin D.
Published: April 2006

Abstract Sections of human pulp tissue taken from the region of a carious exposure in four young patients each having a clinical history of spontaneous dental pain were examined with the electron microscope. All the tissues examined exhibited a generalized edema, and an infiltration with lymphocytes, plasma cells, polymorphonuclear leukocytes and macrophages. Varying degrees of lysis of pulp and inflammatory cells were evident. The unmyelinated nerve axons of the pulp appeared to be least affected. Extracellular lysosomes were present in many of the necrotic areas. Edematous vacuoles were noted in two of the pulp specimens. In some of the sections these vacuoles appeared to be responsible for a physical distortion of adjacent unmyelinated nerve axons. It was postulated that such distortion may be a contributing factor to the pain of pulpitis.

In another of the pulp specimens, micro‐organisms were found intracellularly and extracellularly. Intracellularly they were present within the cytoplasm of polymorphonuclear leukocytes and macrophages and exhibited evidence of lysis. Only two morphological forms, a gram positive rod, and a gram positive coccus were identified.
The effect of turpentine on hamster cheek pouch mucosa: a model of epithelial hyperplasia and hyperkeratosis
Authors: Craig G. T. , Franklin C. D.
Published: April 2006

Abstract Hamster cheek pouches were painted thrice weekly with 50% v/v turpentine in liquid paraffin over periods ranging from 1 day to 16 weeks. Pouch mucosa was examined histologically for changes and measurements of epithelial thickness were made with a calibrated eyepiece micrometer.

An increase in epithelial thickness was first observed 48 h after a single painting and was accompanied by inflammatory changes in both epithelium and connective tissue. Maximal epithelial thickening occurred after 9 weeks of thrice weekly painting. Cheek pouches of animals left without further treatment for up to 1 year following 9 weeks painting were indistinguishable from controls.

The epithelial response to treatment with turpentine is that of a reversible benign epithelial hyperplasia with hyperkeratosis.
Focal epithelial hyperplasia in a group of South Africans: Its clinical and microscopic features
Authors: van Wyk C. W. , Staz J. , Farman A. G.
Published: April 2006

Thirty‐seven cases of focal epithelial hyperplasia were discovered among pupils of reform schools and none among pupils of ordinary schools. This difference in occurrence was significant (P < 0.01). Lesions were either discrete papules or clusters of papules; and the lining mucosa was the most affected part. Eighteen cases were examined microscopically revealing the typical features of the condition. The fact that these lesions occurred in a select group of pupils all of whom are classified as Cape Coloureds point to either a selective distribution of the disease or a spread of the disease among people living in communal circumstances. This pattern of distribution coupled with the clinical and histological features would fit a disease of viral origin which is also communicable.
Intra‐uterine healing of fetal rat oral mucosal, skin and cartilage wounds
Authors: Goss Alastair N.
Published: April 2006

Orofacial wounds, including rupture of the palate, were surgically created in utero on 19½ day Sprague Dawley rat fetuses. Six hours prior to sacrifice 0.1 mgm/100 gm maternal body weight of colchicine was injected subcutaneously. Five fetuses in each group of operated and unoperated controls were sacrificed at 0, 24, 48 and 72 h postoperatively. Serial histological sections in the frontal plane were stained with hemotoxylin and eosin and modified Mallory's.

Rapid and complete epithelialization of oral and skin wounds was observed within the 72 h period. There was a complete lack of inflammatory response, scab formation and involvement of nasal epithelium in healing. Nasal cartilage wounds rapidly rounded off and the perichondrium reformed without evidence of callus formation. These findings are discussed in regard to the etiology of some congenital defects and the prospect of fetal surgical correction of orofacial deformity.
Fluoride distribution in the facial surfaces of human maxillary central incisors
Authors: Koulourides Nlckie , Walker Allen
Published: April 2006

Abstract. The fluoride distributions in the incisal, middle and cervical regions of the facial surfaces of six maxillary central incisors were determined by three successive acid etch biopsy procedures. The fluoride concentrations were adjusted to standardized depths of 0–10μm, 10–20 μm and 20–30 μm. In the biopsy areas the enamel fluoride concentrations decreased with increasing depth. In all the teeth the fluoride content was lowest in the incisal region and highest at the cervical third.
The effect on bone repair of aspirin cones placed in extraction sockets in dogs: a histopathologic study
Authors: Baratieri A. , Deli R.
Published: April 2006

Abstract. Four canines of eight 2‐year‐old dogs were extracted surgically, a mucoperiosteal flap being raised. A standardized pair of the post‐extraction cavities were filled with three aspirin cones, the other pair being used as controls. The flaps were sutured with surgical gut. The dogs were killed at intervals of 2, 4, 6 and 8 weeks; bone blocks including the cavities were resected and decalcified for histologic examination; serial sections were stained with hematoxylin and eosin. Microscopic observation on 2 week samples showed an inflammatory response with granulation tissue in both experimental and control cavities with delayed bone apposition in cavities filled with aspirin cones. The 4, 6 and 8 week samples did not show any major difference between the experimental and control cavities. We observed a decrease in infiltrating of cells followed in both by a similarly increasing amount of fibrous tissue and bone remodeling. These results were due perhaps to the details of the experimental method as the suture allowed aspirin to stay in the cavities for only a short time (2‐3 days), as occurs in clinical practice.
Primary mineralization of dentin in rats after pulp capping with calcium‐hydroxide
Authors: Hirschfeld Z. , Bab I. , Ttamari I. , Sela J.
Published: April 2006

It has been previously reported that short term application of calcium‐hydroxide to the dental pulp resulted in the formation of a dentin bridge with matrix vesicle calcification. The present study deals with the induction of reparative dentin in rat molar pulps by direct capping with calcium‐hydroxide. The teeth were examined after 21 and 35 days. Transmission electron microscopy (TEM) Revealed that the calcification process in the newly formed dentin was characterized by apatite deposition in matrix vesicles and the occurrence of calcifying nodules in the matrix. The persistence of these features of primary mineralization, during the experimental period, was associated with the continuous calcium hydroxide contact with pulp tissue, producing changes in its metabolic state.
Bacterial leakage around dental restorations: its effect on the dental pulp
Authors: Bergenholtz G. , Cox C. F. , Loesche W. J. , Syed S. A.
Published: April 2006

This study revealed that the quantity of bacteria filtered from the base of Class V cavity restorations were directly related to the type of medicament used. Of the brands studied: composite, amalgam, silicate, and guttapercha – each produced varying numbers of bacterial colonies, whereas zinc oxide and eugenol cement showed none. Histopathology of the pulps correlated directly to the microbiological data.
Langerhans cells in candidal leukoplakia
Authors: Daniels T. E. , Schwartz O. , Larsen V. , Dahelsteen E. , Pindborg J.
Published: April 2006

Using histochemical and immunohistochemical methods, we examined specimens of Candidal leukoplakia from the oral mucosa of 5 smokers to determine the morphological relationships between Candida and Langerhans cells (LC) in tissue sections. LC were fairly evenly distributed in control sections, but had a patchy distribution in lesions. Fewer LC were found in lesions than in control tissue, but the difference was not statistically significant. Candidal antigens were not detected on LC by the methods used, but we found ATPase‐positive LC among, or at least near, intraepithelial candidal hyphae. However, sections double‐reacted with anti‐Candida and T6 antibodies to label candidal antigens and LC. respectively, showed a clear zone of epithelium between the T6‐positivc LC and the candidal hyphae. The difference in distribution of ATPase‐positive and T6‐positive LC may indicate locations of 2 subtypes of LC, or a change in T6 antigen expression by the LC closest to the candidal hyphae.
Case history of a cyst
Authors: Grossman Louis I.
Published: April 2006

Abstract The case history of a periapical lesion, probably a cyst, observed over a period of 44 years without endodontic treatment is presented. The radiographic appearance of the lesion changed somewhat over the years, and external root resorption became evident. There is no history of fistula, and the tooth remained asymptomatic during the 44 years.
Effect of root curvature on post length in the restoration of endodontically treated premolars
Authors: Zillich Richard , Yaman Peter
Published: April 2006

Abstract Two hundred and eighteen bi‐rooted maxillary premolars were examined radio graphically to determine the length from the apex at which root curvature occurred. The information may serve as a guide in determining post preparation length. The results of the study indicated that the lingual root was slightly straighter than the buccal root. The curvature of the root was on the average 6.47 mm from the apex on the buccal root and 5.18 mm from the apex on the lingual root.
Replantation of teeth and antibiotic treatment
Authors: Hammarström Lars , Blomlöf Leif , Feiglin Barry , Andersson Lars , Lindskog Sven
Published: April 2006

Abstract Administration of antibiotics is usually recommended when a traumatically avulsed tooth is replanted, in order to prevent bacterial contamination. In the present study, permanent lateral incisors of monkeys were extracted, allowed to dry for 1 h and then replanted. Some teeth had their pulp chambers opened labially and left open for 3 wk after replantation. The monkeys were treated with antibiotics (i.m.) either at the lime of replantation or 3 wk after replantation. In some monkeys, antibiotics were placed in the pulpal cavity. Comparisons were made of the effect of endodontic treatment on periodontal healing and root resorption. The monkeys were killed 8 wk after replantation. It was found that after systemic antibiotic treatment at the time of replantation there was no inflammatory root resorption. Also, endodontic treatment at the time of replantation prevented inflammatory root resorption. When systemic antibiotic treatment was instituted 3 wk after (he replantation, there was no reduction of the inflammatory root resorption as compared with teeth without antibiotic treatment. Application of antibiotics in the pulp 3 wk after replantation almost completely eliminated the inflammatory resorption. In all the treatment groups where administration of antibiotics or endodontic treatment had prevented, reduced or eliminated inflammatory root resorption, 30–45% of the root surface area was ankylotic 8 wk after replantation.
Root curvature localizations as indicators of post length in various tooth groups
Authors: Perez Enrique , Zillich Richard , Yaman Peter
Published: April 2006

Abstract The straight line length available for post preparations in pulps of 957 human teeth was evaluated. Analysis of radiographs in both buccolingual and mesiodistal directions showed that only 2.7% of the teeth studied were straight to the apex in both views. Average straight line lengths were calculated for the different types of teeth and used to offer guidelines for the length of post preparation. Buccal roots of maxillary molars and the mesial roots of the mandibular molars frequently showed straight line lengths insufficient for post preparations.
The effect of saline storage before replantation upon dry damage of the periodontal ligament
Authors: Andreasen Jens Ove , Schwartz Ole
Published: April 2006

Abstract The effect of 30 min of saline storage before replantation of teeth, which had been dried out for 30 min, was studied in 10 Green Vervet monkeys (Cercopithecus aethiops). Maxillary central incisors were extracted and dried out for 30 min, after which 1 incisor was replanted and the other transferred to a saline solution for 30 min before replantation. No splinting or endodontic treatment was carried out. The teeth were examined after 8 wk. Histometric analysis showed identical extent of root resorption in the 2 groups, with ankylosis being the dominant resorption type, and with very limited pulpal repair in either group. It is concluded that saline storage under the experimental conditions chosen had no effect on development of root resorption or pulpal repair, presumably because 30 min dry storage had inflicted close to maximal damage on the periodontal ligament at the root surface. On the other hand, it is of clinical importance that a certain delay in the replantation procedure does not influence periodontal and pulpal healing, as long as the tooth is kept in saline storage. This suggests that replantation under these conditions can be reserved for dental professionals, rather than favoring immediate replantation by anyone ‘on‐the‐spot’.
Mandibular molar with C‐shaped canal
Authors: Barnett Frederic
Published: April 2006

Abstract This case report describes a mandibular molar with a C‐shaped canal. Radiographically, the tooth had a normal morphological appearance with 2 distinct and separate roots. However, the pulp chamber door had only 2 root canal orifices, a mesiolingual orifice and a buccal C‐shaped trough that was continuous from the normal location of the mesiobuceal canal to the location of the distal canal. The trough was extensive and persisted along the entire length and width of the C‐shaped root canal. During endodontic treatment of the tooth, it became evident that the C‐shaped canal bifurcated into a mesiobuceal and a distal canal in the apical 2 mm of the root. It appears that this case demonstrates the morphological pattern of the true C‐shaped canal.
Rate and predictability of pulp revascularization in therapeutically reimplanted permanent incisors
Authors: Kling Margareta , Cvek Miomir , Mejàre Ingegerd
Published: April 2006

Abstract The aim of the present investigation was to study the frequency of pulp revascularization in therapeutically reimplanted incisors as well; is its relationship with the following factors: width of apical foramen, duration of extra‐alveolar lime, storage conditions and postoperative administration of antibiotics. Out of 72 immature teeth (width of apical foramen 1.1–5.0 mm) the pulp was revascularized in 13 (18%), while in 88 mature teeth (width of apical foramen 1.0 mm or less) no revascularization occurred. Among parameters tested statistically in immature teeth, a significantly increased frequency of revascularization (p < 0.05) was only found in teeth reimplanted within 45 minutes after avulsion, when compared with teeth reimplanted after a longer extra‐alveolar time, and in mandibular incisors when compared with maxillary incisors (p < 0.01). All teeth in which revascularization did not occur exhibited a periapical radiolucency and/or external inflammatory root resorption.
Re‐eruption of completely intruded immature permanent incisors
Authors: Shapira Joseph , Regev Liora , Liebfeld Harry
Published: April 2006

Abstract The treatment approach for 4 completely intruded immature permanent teeth is described. Urgent endodontic treatment was required in 3 of the intruded teeth while awaiting spontaneous re‐eruption. Access to the pulp chambers was obtained by palatal gingivectomy around and above the embedded teeth. Considerable acceleration of the re‐eruption was noted after the surgery and the debridement of the root canals.
A new treatment of heterotransplanted teeth to prevent progression of root resorption
Authors: Sperling Israel , Itzkowitz Dov , Kaufman Aryeh Y. , Binderman Itzhak
Published: April 2006

Abstract A new treatment is suggested to prevent root resorption of heterotransplanted teeth. After conservative root canal treatment, the root surface was treated with concentrated citric acid solution to demineralize the root surface. The demineralized collagenous matrix was then treated with n‐acetylcysteine to inhibit collagenase activity and collagen degradation. Two cases are presented. The initial results supported the notion that anti‐collagenase drugs might be useful in preventing resorption of mineralized collagenous matrices such as cementum, dentin and bone.
Demineralized dentin, hydroxylapatite and dentin chips as apical plugs
Authors: Brandell D. Wylie , Tora‐binejad Mahmoud , Bakland Leif K. , Lessard George M.
Published: April 2006

Abstract Demineralized dentin, hydroxylapatite, or dentin chips were condensed into the apical 2 mm of canals with perforated apexes in 36 anterior teeth of 8 adult cynomolgus monkeys. The coronal sections of the canals were then obturated with gutta percha and Grossman's sealer. Twelve additional canals with perforated apexes were obturated 2 mm short of their radiographic apexes and served as controls. The amount of hard tissue formation and the degree of inflammation were evaluated after 3 and after 6 months. No differences were noted between the various materials after 3 months. However, after 6 months the samples with apical plugs of hydroxylapatite had more hard tissue formation and less inflammation than the others.
Five root canals in a mandibular first molar
Authors: Friedman Shimon , Moshonov Joshua , Stabholz Adam
Published: April 2006

Abstract Endodontic therapy was performed in a mandibular first molar with 5 root canals, 3 of which were located in 3 distal roots. The existence of 3 distal root canals was assumed after careful reading of radiographs. Two of the distal root canals were close to one another and located buccally to the midline. The 3rd was remote, located lingually. The 2 mesial root canals were found in their normal locations. This case demonstrates a rare anatomical configuration, and joins with recent reports in the emphasis of the existence of such configurations in mandibular first molars.
Root canal posts — some prosthodontic aspects
Authors: Glantz Per‐Olof , Nilner Krister
Published: April 2006

Abstract Prosthodontic treatment of non‐vital teeth following endodontic therapy faces problems originating from the fact that such teeth generally have damaged clinical crowns, necessitating retention beyond the remaining coronal portions of the teeth. Additional intraradicular retention can be obtained by means of root canal posts. The total need for retention shows wide variations. Each case, therefore, should be carefully analyzed before decisions arc made about post types, post designs and post dimensions. The need for retention is dependent upon intermaxillary relations, type of prosthetic appliance, position of tooth, and volume and shape of remaining tooth substance. At least 3 mm of well‐sealed root canal should be left apically to the post preparation, but normally the post preparation should not extend into the apical one‐third of the root. Sufficient additional retention through a post is usually achieved when the extention of the post into the root canal at least equals the difference between the mean height of the prepared coronal dentin and the height of an ideal crown preparation of the tooth.
The effect of apical foramen patency on condensation stresses
Authors: Gimlin Dennis R. , Parr Charles H. , Aguirre‐Ramirez Gilbert
Published: April 2006

Abstract Mathematical models and computer‐based engineering tools were used to evaluate the effect of a patent or closed apical foramen on stresses that are produced within gutta‐percha during condensation. We examined a mathematical model of a tapered canal with a definite constriction and compared the results when the apical foramen was closed or open. When the canal was closed an almost constant stress was seen throughout the gutta‐percha. When the foramen was open a sharp increase in lateral stress was observed in the apical portions of the canal. The constriction near the foramen caused the gutta‐percha to be squeezed together and the stress was increased. This increases the likelihood that the gutta‐percha is well adapted to the apical constriction. However, the stresses are also transferred to the surrounding dentin, resulting in a stress concentration near the apical foramen where the bulk of dentin is minimal.
External root resorption in patients with secondary bone‐grafting of alveolar clefts
Authors: Gerner Nina Wiencke , Hurlen Bjern , Bergland Olav , Semb Gunvor , Bever‐Olsen Eva M. S.
Published: April 2006

Abstract External root resorption as a complication to bone grading of alveolar clefts is described and a treatment procedure evaluated. The root resorption was related to possible etiologic factors. In this study a total of 419 cleft sides in 354 patients were treated with iliac bone grafting. External dental root resorption was diagnosed radiographically in 16 teeth. Thirteen of these teeth were treated at the Dental Faculty, University of Oslo. The treatment procedure was a combination of enclodontic treatment and a surgical flap operation to remove granulation tissue in the resorptive defect. Non‐zinc silver amalgam was used for the restoration of the defects. Arrest of the lesions was achieved in 11 teeth, evaluated 18–36 months post‐operatively. The resorption described is progressive in nature and shows a characteristic localization in the cervical area of the tooth.
Sinusitis caused by endodontic materials displaced into the maxillary sinus
Authors: Bjornland Tore , Haanss Hans R. , Beyer‐Olsen Eva Margrethe S.
Published: April 2006

Abstract Three cases of endodontically‐induced maxillary sinusitis are presented. Two of the cases had previously been treated with overextension of gutta‐percha points. The 3rd patient had been treated endodontically approximately 15 years earlier. All patients were treated with surgical removal of the endodontic material via an intraoral approach to the sinus.
Development of predictable periapical lesion monitored by subtraction radiography
Authors: Pascon Elizeu Alvaro , Introcaso Joseph Hudson , Langeland Kaare
Published: April 2006

Abstract Forty‐eight teeth of two baboons were used to establish a methodology for the development of predictable periapical lesions. The canines and third molars were used as controls. All pre‐ and post‐operative radiographs were taken using modified Precision® X‐ray beam guiding to maintain exposure geometry. After routine endodontic access preparation, the pulps were damaged 3–4 mm short of the apex, dental plaque was introduced and mixed with pulp debris, and the access opening was closed with amalgam. Control radiographs were taken at 7‐day intervals. Ten experimental and two control teeth were used for each observation period of 1, 4, 8, and 20 weeks. The radiographs were analyzed using computerized temporal subtraction. After the animals were killed, the specimens were processed for histologic examination. In all cases, pulpal necrosis and bacteria were present in the root canal, and in the periapical area adjacent to necrotic tissue. The periapical lesions had a mixture of inflammatory cells, with predominance of plasma cells, lymphocytes and multinucleated cells. Racliographic analysis by subtraction radiography showed hard tissue changes as early as 7 days. The method predictably developed periapical lesions, which could be monitored by subtraction radiography, and there was a correlation established between radiographic and histologic findings.
Histological evaluation of the effect of intrapulpal anesthesia in pulpotomies
Authors: Massone Joaquin Enrique , Goldberg Fernando , Barros Ramon Enrique
Published: April 2006

Abstract The effect of intrapulpal anesthesia prior to pulpotomies was histologically studied on 12 young human premolars. In 9 teeth (75%) a mineralized bridge adjacent to the remaining pulp tissue containing dilated blood vessels was observed. The rest (25%) had no mineralized bridge and the remaining pulp tissue showed inflammation with hemorrhage as well as necrotic areas.
Root form and canal anatomy of mandibular first molars in a southern Chinese population
Authors: Walker Richard T.
Published: April 2006

Abstract Racial differences in dental crown morphology have long been recognised, but the diverse aspects of root form and canal anatomy of human teeth have not received the same attention. The majority of books on dental anatomy fail to supply detailed information of the features of root and root canal morphology that occur at particularly high frequency in Mongoloid populations. These features have not been systematically documented and the implications that these variations may have upon clinical endodontics have not been fully reported. In this study 100 mandibular first molars extracted from Hong Kong Chinese patients were examined visually and radiographically. For each tooth, the number of roots, root canals, and apical foramina were noted. Fifteen per cent of the mandibular first molars examined were found to be 3‐rooted. Forty‐five per cent of the sample displayed 2 distal canals and 28% of the teeth had 2 separate distal apical foramina. The frequency of the second distal canal is higher than the previously reported findings for non‐Mongoloid groups.
Release and diffusion through human tooth roots in vitro of corticosteroid and tetracycline trace molecules from Ledermix® paste
Authors: Abbott Paul Vincent , Heithersay Geoffrey Sinclair , Hume Wyatt Roderic
Published: April 2006

Abstract The release of corticosteroid and antibiotic tracer molecules in Ledermix® paste from the pulp space to the external environment of human tooth roots was determined in vitro. For demeclocycline little of the tracer was released through the root apex; the great majority diffused through dentine. For triamcinolone about one‐third of the tracer left the roots via the apical foramen; the remainder exited via the dentine. The rate of release of the tracers was highest during the first day, and declined exponentially with time thereafter. After 14 weeks, 98% of triamcinolone and 66% of demeclocycline had been released. In the teeth examined, diffusion rate was not related to the age or sex of the donor. Total release of the tracers was directly related to the area of contact between the paste and dentine. The data obtained are of immediate clinical relevance, and also add to our general understanding of drug dynamics in tooth roots.
Occurrence of traumatic injuries in the oromaxillary region of children in a Japanese prefecture
Authors: Uji Toshiyasu , Teramoto Toyonori
Published: April 2006

Abstract The authors conducted a survey by sending questionnaires to school‐aged boys (7966) and girls (7856) in Kumamoto Prefecture, to study the actual condition of traumatic injuries of teeth and in the maxillary and mandibular regions by comparing the results with those reported by others. An average of 21.8% of the pupils suffered from some kind of trauma in the oral region. It was also found that 37.7% of the traumas resulted from falls and 29.2% from sporting activities. Tooth luxation and fractures accounted for a relatively high percentage of the tooth injuries: 17.3% for the former and 6.9% for the latter, while exarticulation was only 1.6%. Of the total number of traumas, only 12.9% were treated at hospitals or dental clinics. The rest were left untreated.
Orofacial pain – troll and control: five topics on clinical problems
Authors: Helee Berit
Published: April 2006

Abstract Pain is etymologically combined with penalty, emotionally with anxiety and depression, and physiologically with inflammatory processes and other kinds of pressure augmentation in the tissues. Pain is a subjective experience that cannot be measured or “objectively” verified by other individuals. Reactions to pain, however, can be registered by others. Pain in the orofacial area may have several etiological explanations. Since the functional pattern of the area is multi‐faceted, persisting pain in the area most likely has a multi‐factorial background, and also a variety of effects. Treatment should be made considering delicate diagnostical distinctions. A thorough clinical examination contains lots of treatment components. This paper discusses some psychological factors in the diagnosis and treatment of orofacial pain.
Ciprofloxacin treatment of periapical Pseudomonas aeruginosa infection
Authors: Barnett Frederic , Axelrod Peter , Tronstad Leif , Slots Jorgen , Graziani Amy , Talbot George
Published: April 2006

Abstract Survival of bacteria in periapical tissues may be the reason for endodontic failures. This case report describes the treatment of a patient with periapical lesions refractory to endodontic treatment. Microbiological sampling from fistulae associated with the lesions revealed the presence of Pseudomonas aeruginosa. Phenoxymethyl penicillin, metronidazole and carbenicillin were ineffective in eliminating the periapical infection. However, an investigational antibiotic, Ciprofloxacin, which was administered orally twice daily for 15 weeks, proved to be an effective, safe and convenient medicament in the treatment of periapical Pseudomonas aeruginosa infection. The fistulae closed in less than 2 weeks and a radiograph taken during the fourteenth week of therapy showed healing of the apical periodontitis with osseous regeneration. It is suggested that Ciprofloxacin is a valuable agent in the treatment of apical periodontitis, and probably other odontogenic infections caused by susceptible aerobic gram‐negative bacilli.
Resorption and mineralization processes following root fracture of permanent incisors
Authors: Andreasen Frances M. , Andreasen Jens O.
Published: April 2006

Abstract The records of 85 patients treated for 95 root fractures of permanent incisors and followed regularly for up to 11 years were studied with respect to healing events after injury. The radiographic exposure best suited for disclosing root fractures in the apical third of the root was a steep occlusal exposure, while a conventional bisecting angle periapical exposure was optimal for revealing fractures in the cervical third. It is concluded that both exposures should, therefore, be used at the initial examination at the time of injury. Root resorption processes were observed in 60% of the material and could usually be detected within one year after injury. These preceded fracture healing and obliteration of the apical and/or coronal root canals. The changes observed represented one or more of four resorption entities: 1) external surface resorption, characterized by the rounding of the fracture edges mesially and/or distally; 2) internal surface resorption, manifested as rounding of the fracture edges centrally, in the apical and coronal root canals, at the intersection between the pulp canal and fracture line; 3) internal tunneling resorption, going behind the predentin layer and burrowing along the root canal walls of the coronal fragment; and 4) transient apical breakdown of the apical lamina dura. While the resorption processes were self‐limiting and required no treatment, the pattern of resorption and pulp canal obliteration appeared to be decisive for the type of fracture healing. Thus, all resorption entities collectively and internal tunneling resorption particularly were significantly related to healing at the fracture site by interposition of connective tissue. However, when seen alone, internal surface resorption was significantly related to fracture healing by hard tissue union. The different root resorption entities may represent osteoclastic activity connected with the ingrowth of new vascularized connective tissue into the fracture site or the coronal part of the root canal.
Root canal anatomy of mandibular first premolars in a southern Chinese population
Authors: Walker Richard T.
Published: April 2006

Abstract Racial differences in dental crown morphology have long been recognized, but the frequency of genetically determined variations in the root canal anatomy of teeth has not been fully established. There is, therefore, a need to study the morphology of non‐Caucasoid teeth to establish the existence and prevalence of racially determined root canal variations. In this study 100 mandibular first premolars of Chinese origin were accurately identified and radiographed in vitro to establish the frequency of root canal bifurcation. Thirty‐six per cent of the sample presented with more than one canal. The division of these canals occurred at various levels of the root, and in all but one of the teeth the canals remained separate.
Restored vitality in luxated teeth assessed by laser Doppler flowmeter
Authors: Gazelius Bertil , Olgart Leif , Edwall Björn
Published: April 2006

Abstract Revascularization of the pulps in 4 luxated lower incisors in an 11‐year‐old boy was demonstrated with a laser Doppler flowmeter. Pulpal blood flow arrested at the 1–week control was partly restored at 6 weeks and reached normal values 9 months after the trauma. Pulpal obliteration was recognized after 9 months and was pronounced at the 1–year and 2–year controls. Electrometric sensitivity started to appear in 3 of the teeth at 9 months and was further restored in all teeth at the 1–year and 2–year controls.
Prognosis of root‐fractured permanent incisors — prediction of healing modalities
Authors: Andreasen Frances M. , Andreasen Jens O. , Bayer Thomas
Published: April 2006

Abstract A population of 85 patients, comprising 95 root‐fractured permanent incisors followed up to 11 years, was studied prospectively for the type of fracture healing that occurred (i.e. union of the fragments by interposition of hard tissue (HT) or connective tissue (CT), or nonunion characterized by interposition of granulation tissue between the fragments (GT)). Initial treatment was provided according to established treatment guidelines by the attending oral surgeon at the emergency room. Follow‐up examination and treatment were provided by 2 of the authors. It appeared that GT could be diagnosed after approximately 3 weeks, while HT or CT could be diagnosed approximately 6 weeks after trauma. Many factors considered one at a time were found to have a significant or nearly significant effect on the type of fracture healing that occurred. However, a multivariate regression analysis revealed that the following factors were significantly related to fracture healing by HT: a large diameter of the apical foramen and severity of luxation of the coronal fragment (concussion/subluxation > lateral luxation > extrusion); fracture healing by CT: the presence of restorations in the injured teeth at the time of injury and the presence of marginal periodontal disease; and fracture nonhealing by GT: type of fixation (i.e. orthodontic band fixation versus acid etch or no fixation), antibiotic therapy, a constricted apical foramen, increased loosening of the coronal fragment, and stage of root development (GT never occurred in teeth with open apices). It was previously demonstrated following luxation injuries that type of luxation, stage of root development and type of fixation (orthodontic bands versus acid etch or no fixation) determined the prognosis of pulp survival. It therefore appears that the general factors that are able to predict the type of healing seen after root fracture are the same as those after luxation injuries, supporting the hypothesis that root fractures are another form of luxation injury, this time of only the coronal fragment.
A longitudinal study of changes in frequency and technical standard of endodontic treatment in a Swedish population
Authors: Eckerbom Mats , Andersson Jan‐Erik , Magnusson Tomas
Published: April 2006

Abstract Longitudinal studies of endodontic treatment are rare. The purpose of this investigation was to study changes in frequency, technical standard and treatment need in a Swedish population with an interval of 5–7 years. The number of endodontically treated teeth in the population increased while the number of periradicular radiolucencies was at about the same level at the second examination. The number of radiolucencies found in endodontically treated teeth was reduced while it was increased in untreated teeth. The number of root fillings ending ≤2 mm from the apex of the tooth as well as fillings with a proper seal had increased at the second examination, but still only 40.2% ended ≤2 mm from the apex of the tooth and 59.1% of the root fillings were judged to have a proper seal. It was concluded that a great need for endodontic treatment existed in the population examined. A slight improvement in the quality of the treatment was evident at the second examination. However, the technical standard was still poor and obviously affected the outcome of the treatment. It is the opinion of the authors that endodontic treatment methods should be simplified as much as possible in an effort to improve the technical quality of the treatment. The prognosis of endodontic treatment would then improve as well.
Pulpal pathosis and severe alveolar lesions: a clinical study
Authors: Hirsch Robert S. , Clarke Nigel G. , Srikandi Woro
Published: April 2006

Abstract Gingivitis is widely believed to be the precursor of crestal alveolar bone destruction (periodontitis) in some individuals. However, there is no correlation between gingivitis and severe localized lesions of alveolar bone. Specific ‘periodontopathogens’ of the indigenous oral flora are hypothesized to be the cause of localized lesions but the evidence to date is one of association only. Acute and chronic pulpal inflammation are known causes of irritation to the periodontal ligament and alveolar bone; retrograde pockets may subsequently form. Contamination by indigenous organisms best adapted to the special environment of the deep pocket could be expected to follow the establishment of the new conditions. This study was undertaken to examine the clinical and histological status of the pulps of teeth affected by severe localized alveolar lesions. A total of 153 teeth in 90 subjects were studied; full periodontic and endodontic assessments were made. Seventy‐seven teeth responded in the normal range to pulp testing, but 52% of these had no recoverable tissue from their root canal systems on endodontic opening. The findings indicated that pulpal pathosis was not clinically detectable in the majority of teeth studied when conventional endodontic diagnostic tests were applied. Rather, the presence of localized severe alveolar defects was a more accurate predictor of pulpal pathosis. The strong association between pulpal pathosis and localized, severe alveolar defects and the appearance of similar lesions in dry skulls indicates that the alveolar lesions were of pulpal origin with spread to localized periodontal sites.
Differentiation of radicular cyst and granulomas using computerized tomography
Authors: Trope Martin , Pettigrew James , Petras James , Barnett Frederic , Tronstad Leif
Published: April 2006

Abstract The purpose of this investigation was to study periapical lesions by means of computerized tomography to ascertain if this noninvasive method could be of value in distinguishing between radicular cysts and granulomas. Periapical radiographs were taken of the teeth of 60 human cadavers. Periapical radiolucencies were seen in conjunction with 33 teeth. Based on the periapical radiographs, an oral radiologist (J.P.) attempted to select 4 granulomas and 4 cysts from the 33 radiolucencies. Computerized tomography was performed on the root tips and the periapical lesions of these 8 teeth. The roots and periapical lesions were then surgically removed and prepared histologically for microscopic examination. In the tomographs, 7 of the periapical lesions had a cloudy appearance with a density similar to each other and to the surrounding soft tissue. In the eighth lesion a homogeneous dark area with a distinctly lower density could be distinguished from surrounding cloudy areas. Histologically, the dark area was shown to be an epithelialized cyst cavity. The other 7 lesions were granulomas. Thus, a cyst could be differentiated from periapical granulomas by computerized tomography because of a marked difference in density between the content of the cyst cavity and granulomatous tissue.