bluuebunny/crossref_metadata_2025 huggingface dataset:
Darier's disease: a focal abnormality of cell adhesion
Authors: Burge S. M. , Millard P. R. , Wojnarowska F. , Ryan T. J.
Published: April 2006

Cell adhesion in clinically normal and involved skin in Darier's disease has been investigated using a suction blister technique. We have been unable to detect a subclinical abnormality in cell adhesion which could predispose to the development of acantholytic papules. There may be synthesis of functionally deficient desmosomes, increased breakdown of desmosomes or abnormalities in other adhesion proteins on the surface of the keradnocyte in Darier's disease, but the abnormality in adhesion is focal and restricted to the clinically and histologically abnormal papules.
Distribution of lymphocytes bearing TCRγ/δ in cutaneous lymphocytic infiltrates
Authors: Horn Thomas D. , Farmer Evan R.
Published: April 2006

A monoclonal antibody to the recently characterized T lymphocyte expressing a T cell receptor bearing γ and δ chains (TCRγ/δ) was applied to 60 biopsy specimens spanning a wide range of diagnoses and containing a variable number of T lymphocytes. TCRγ/δ+ cells were not enriched in the tissues examined, representing between 0–5% of the total CD3 positive T lymphocyte population. TCRγ/δ+ cells were identified in 27 cases (45%). The distribution of the TCRγ/δ‐bearing cells was remarkable for preferential stratification at upper cutaneous levels, within the epidermis and papillary dermis in some cases of mycosis fungoides. Benign infiltrates lacked a similar pattern. The role of TCRγ/δ+ cells is uncertain. The data do not reveal a consistent number or distribution of these cells in cutaneous infiltrates.
Immunohistochemistry of intravascular papillary endothelial hyperplasia
Authors: Albrecht S. , Kahn H. J.
Published: April 2006

Intravascular papillary endothelial hyperplasia is an interesting endothelial proliferation, the nature of which has aroused some controversy. Five cases were studied by light microscopy and by immunohistochemistry using antibodies to Factor VHI‐related antigen (FVIII‐rAg), ferritin, α1‐antitrypsin, α1‐antichymotrypsin and vimentin and were compared with conventional intravascular organizing thrombi. The results show a similar progression of the immunophenotype of the endothelial cells in both entities: they are initially positive for ferritin, then acquire vimentin positivity and only display FVIII‐rAg positivity in advanced (“mature”) lesions. This suggests that intravascular endothelial hyperplasia is closely related to organizing thrombi and is probably a peculiar form thereof.
Acrodermatitis chronica atrophicans: A light and electron microscopic study
Authors: de Koning J. , Tazelaar D. J. , Hoogkamp‐Korstanje J. A. A. , Elema J. D.
Published: April 2006

Degeneration of the elastica and collagen fibres in skin biopsies from patients with acrodermatitis chronica atrophicans was studied with light and electron microscopy. Elastic fibres were involved in the infiltrative stage while the elastin plexus was still present. In the atrophic phase, only fragments of elastic and oxytalan fibres were seen and the elaunin plexus was absent. Some collagen fibres were surrounded by osmiophilic material. In all biopsies, myelin sheaths were collapsed without axon structures. Spirochetes could be demonstrated in 69% of the biopsies and were most numerous in infiltrative and nodular lesions. The loss of elasticity of the skin in the atrophic phase may be caused by the destruction of both elastic and elastin fibres.
Scanning electron microscopy of calcium hydroxide induced bridges
Authors: Ulmansky M. , Sela J. , Sela M.
Published: April 2006

Abstract. Calxyl, a commercial preparation of calcium hydroxide, induces the formation of a calcified bridge on the dental pulp after pulpotomy. Since the quality of such bridges is not always the same, it was felt necessary to study bridge structure by means of the scanning electron microscope.

The present results are observations made with the aid of scanning microscopy on three specimens which revealed that calcium hydroxide induced bridges present large defects and a particular topography.
The calcifying ghost cell odontogenic tumor – or the calcifying odontogenic cyst
Authors: Fejerskov O. , Krogh J.
Published: April 2006

Abstract. The paper reports on two new cases of calcifying odontogenic cysts, and gives a survey of 50 cases reported in the literature. In one case the ultrastructure of the characteristic ghost cells was examined. Most of the cells were anuclear or contained pyknotic nuclei. The only organelles found were very thick electro‐dense fibrils of uniform size sharply defined against large empty spaces. Small needle‐like crystalloid structures were seen in most cells. The ghost cells lying free in the connective tissue or embedded in the osteiod material had either lost their plasma membranes entirely or only remmants of it could be found. Histologically there is a marked similarity between the published cases. The epithelium forming either cysts or islands shows a distinct basal layer of columnar cells. Above the basal layer the cells are often stellate. Ghost cells are observed. Scattered both in the epithelium and in the surrounding connective tissue. Outeoid or dentinoid material was observed close to the ghost cells in 14 of 36 cases. Calcified deposits have been described in the ghost cells in 26 out of 36 cases reported. The material demonstrates an almost equal sex distribution of the tumor, and an almost equal distribution between the anterior maxilla and mandible. Two‐thirds of the tumors were intra‐osseous, and one‐third were extra‐osseous. The tumor occurs in all age groups, with an increased incidence in the age group of 10–19 years. There is no similarity between the clinical features of this lesion and those of ameloblastoma and calcifying odontogenic tumor.

The authors interpret the lesion as a tumor or hamartoma with a marked tendency for cystic degeneration. Therefore the designation calcifying ghost cell odontogenic tumor has been proposed.
Fibrous tumor of infancy — Report of a case originating in the oral cavity
Authors: Takagi Minoru , Ishikawa Goro
Published: April 2006

Abstract. A fibrous tumor of infancy of the floor of the mouth is reported. The tumor was characterized by congenital occurrence, deeply infiltrating, dense immature fibroblastic cells, focal chondroid differentiation, rapid new growth 3 years following irradiation and no recurrence 6 years after incomplete excision. The diagnosis of an aggressive infantile fibromatosis or juvenile fibromatosis, differentiated fibrosarcoma type, was considered to be the most acceptable.
Proteins in fluid from non‐keratinizing jaw cysts
Authors: Skaug Nils
Published: April 2006

Abstract. Fluids from 32 non‐keratinizing jaw cysts were examined by polyacrylamide gel disc electrophoresis, and by immunoelectrophoresis and double diffusion in agar against rabbit anti‐human serum and rabbit antisera monospecific for six different plasma proteins. Albumin, α1‐antitrypsin, α1‐acid glycoprotein (orosomucoid), transferrin, IgG, IgA, and IgM were invariably recognized. Most cyst fluids also reacted with antiserum to α1‐lipoprotein, α2‐macroglobulin, β1 C/β1A‐globulin (C3/C3c), and fibrinogen. Cyst fluid “fibrinogen” which showed somewhat slower electrophoretic migration than plasma fibrinogen, appeared as two precipitin bands or as one line with an apparently split cathodic end. Two cyst fluids exhibited one additional “fibrinogen” line located in the α1‐globulin region. C3, which was not detected in all cyst fluids, displayed an electrophoretic mobility between that of β1C‐ and β1A‐globulin of serum. In two cases an even faster C3 subtraction appeared. Double diffusion gave a “reaction of identity” between albumin and the α‐ and β‐globulins of cyst fluid and autologous scrum. Cystic “fibrinogen” and fibrinogen of human plasma gave a “reaction of partial identity”. These findings indicate that albumin and the main α‐ and A‐globulins of fluid from non‐keratinizing jaw cysts are derived from plasma and that breakdown products of fibrinogen or fibrin are also present. High levels of IgG and IgA, but decreased amounts of α2‐macroglobulin and C3 as compared to autologous serum are also suggested.
Experimental autoallergic parotitis
Authors: White Stuart C.
Published: April 2006

Abstract. An experimental autoallergic parotitis in the rat with a high incidence, high mean grade of lesion and short time of onset is described.
Proteins in fluid from non‐keratinizing jaw cysts
Authors: Skaug Nils
Published: April 2006

Abstract. Contents of IgG, IgA and IgM in the fluids from 45 non‐keratinizing jaw cysts, and of albumin, α1‐acid glycoprotein (orosomucoid), α1‐antitrypsin, α2‐macroglobulin, ceruloplasmin, C3 (C3/C3c‐globulin), and transferrin in 15 of these cyst fluids have been determined by single radial immunodiffusion. In addition, cystic “fibrinogen” was measured in 37 cyst fluids. The mean ratios of IgG:IgA:IgM were for cyst fluid 20.1:4.8:1 and for the autologous serum 14.6:2.5:1. On the average, cyst fluid contained IgG, IgA and IgM in concentrations 1.2, 1.7 and 0.9 times, respectively, that of autologous serum. These ratios as well as data obtained from other calculations indicate partly local synthesis of cyst fluid immunoglobulins, mainly IgA and IgG. Remarkably high IgA levels were found in some cyst fluids. In apical periodontal cyst fluid there was a highly statistically significant positive correlation (P<0.001) between the concentrations of IgG and IgA. No statistically significant differences were found between the Ig quantities in fluid from apical periodontal, follicular and residual cysts. The non‐immunoglobulin proteins other than fibrinogen, which is structurally altered when present in cyst fluid, occurred in lower concentrations than in autologous serum. Cyst fluid to autologous serum concentration ratios (CCF/CS ratios) for the different proteins have been calculated. Considerably higher CCF/CS ratios were found for immunoglobulins than for non‐immunoglobulin proteins with similar molecular weights. The implications of the findings for cyst wall permeability and clearance of proteins in cyst fluid arc discussed.
Changes in the fine structure of the dental pulp in human caries pulpitis
Authors: Torneck Calvin D.
Published: April 2006

Abstract. An investigation into the nature of the inflammatory infiltrate of early caries pulpitis in humans indicates that the basis response is a mononuclear one in which plasma cells predominate. From their morphological appearance it could be stated that the plasma cells present were engaged in the formation of antibody. It was suggested that the stimulus for this antibody production could arise from substances in the carious lesion or from locally sensitized dental pulp. Although several methods of antibody release from plasma cells were discussed, the only one noted in the study was that occurring as a result of the apparent fusion of distended cisternae of rough endoplasmic reticulum with the plasma membrane.
Histologic and histometric study of the effect of fluoride on the rat mandibular condyle
Authors: Kameyama Yoichiro
Published: April 2006

Abstract. The effect of fluoride on the rat mandibular condyle was studied histologically and histometrically. The condyles of the rats that received 50 ppm fluoride in the drinking water for 17 weeks did not differ in structure from those of the control rats fed tap water containing 1 ppm fluoride. However, the condyles of the rats given 100 ppm fluoride in the drinking water for the same period showed a significant increase in both the thickness of the cartilage layer (P < 0.02) and the density of cancellous bone (P < 0.01) when compared to the controls. The thickening of the cartilage layer was due to an increase in the number of hypertrophied chondrocytes. The trabeculae of cancellous bone were thicker and consequently the bone marrow spaces were extremely reduced. The trabeculae contained more calcified cartilage in their cores.
Identification of hamster thymus‐derived lymphocytes employing rabbit anti‐hamster brain serum
Authors: Rheins Melvin S. , Cavalaris C. J. , Filppi Joyce A. , Burns R. A.
Published: April 2006

Rabbit anti‐hamster brain sera prepared from the brains of Syrian and Chinese hamsters were evaluated for their potential to identify thymus‐derived lymphocytes present in these animals. The unabsorbed antisera were cytotoxic in vitro for both homologous and heterologous thymocytes and splenocytes. Following absorption with hamster liver and erythrocytes, the antisera remained toxic for thymocytes, but were less toxic for splenocytes. Comparative testing of both the rabbit anti‐Syrian and anti‐Chinese brain sera with rabbit anti‐C3H mouse brain serum indicated that considerable cross‐reactivity exists between the different anti‐brain sera. The in vivo administration of any of the antisera to C3H mice resulted in a lowered titer to the thymus‐dependent sheep erythrocyte antigen response as measured by the hemolysis‐in‐gel technique. In vitro treatment with the anti‐brain sera had no effect on plaque‐forming cells present in the spleen.
The nature of epithelial proliferation in apical granulomas
Authors: Summers L. , Papadimitriou J.
Published: April 2006

Small sections of granulomas containing proliferating epithelium were incubated with a radio‐opaque marker (Thorotrast®) and tissue culture medium. Electron microscopic examination demonstrated that some epithelial cells had the potential to take up the marker whereas in control sections of apical cysts this did not occur. The implications of these results are discussed.
Ultrastructural characteristics of mast cells from a canine mastocytoma maintained in vitro*
Authors: Cobb Charles M. , Birkedal‐Hansen Henning , Denys Francis R.
Published: April 2006

Abstract. Mast cells obtained from a canine mastocytoma were maintained in cell culture for a period of 11 weeks. Samples of these cells were harvested for electron microscopic examination after 9 weeks in vitro. Although the overall morphologic appearance was sufficient to allow their identification as mast cells, the tumor cells differed in several respects from descriptions of normal tissue mast cells.

In contrast to normal tissue mast cells, the tumor cells exhibited peripheral accumulations of microfilaments, randomly dispersed microtubules, and small clusters of smooth endoplasmic reticulum. The tumor mast cells also presented three different granule types: spherical granules with an amorphous and electron dense matrix; irregularly shaped granules possessing a limiting external membrane and an internal matrix containing laminated and/or coiled structures; and granules containing loosely coiled, unorganized membrane structures similar in appearance to myelin whorls.

The canine mastocytoma is an excellent source of mast cells as they can be obtained in large numbers without contamination by extraneous cell types and the cells can be maintained in vitro for extended periods of time.
Some observations on the fluids of odontogenic cysts
Authors: Browne R. M.
Published: April 2006

Abstract. The fluids of 44 dental cysts, 19 dentigerous cysts, 36 odontogenic keratocysts, and 12 ameloblastomas have been investigated. The incidence of epithelial cells, inflammatory cells, cholesterol crystals and bacteria was recorded in smears. There was a high incidence of epithelial cells in odontogenic keratocysts and not in other lesions. Cholesterol crystals had a similar incidence in all lesions. The proportion of the soluble proteins and total protein content was determined from cellulose acetate electrophoresis. Dental cysts contained an average of 51.19 % albumin, 17.52 %β globulin, 22.04 %γ globulin, and 6.30 g/100 ml protein. Dentigerous cysts contained an average of 61.35 % albumin, 13.98%β globulin, 12.70%γ globulin and 5.40 g/100 ml protein. Odontogenic keratocysts contained an average of 78.03 % albumin, 7.51 β globulin, 7.91 γ globulin, and 2.09 g/100 ml protein. Ameloblastomas contained an average of 67.38% albumin, 12.83%β globulin, 12.60 γ globulin and 4.86 g/100 ml protein. The immunoglobulin content was determined by single radial immunodiffusion. Dental cysts contained an average of 488.9 mg/100 ml IgA, 2535.4 mg/100 ml IgG, and 135.6 mg/100 ml IgM. Dentigerous cysts contained an average of 308.4 mg/100 ml IgA, 1618.2 mg/100 ml IgG, and 155.6 mg/100 ml IgM. Odontogenic keratocysts contained an average of 135.6 mg/100 ml IgA, 491.9 mg/100 ml IgG, and 54.1 mg/100 ml IgM. The significance of these findings in the pathogenesis and diagnosis of these lesions is discussed.
Salivary gland tumors: review of 643 cases
Authors: Main J. H. P. , Orr J. A. , McGurk F. M. , McComb R. J. , Mock D.
Published: April 2006

Abstract. 643 cases of salivary gland tumors constitute two series of histological sections that were studied from hospitals and dental schools in Southeast Scotland and Southern Ontario. The Scottish series represented epithelial tumors of the parotid and intra‐oral salivary glands, but the Canadian series also included tumors of the submandibular and sublingual glands. Classification was based on that recommended by the World Health Organisation (Thackray 1972). While direct statistical comparisons between the two series are not appropriate, the differences between them suggest that malignant tumors are more common in Canada. The Scottish series contains the largest proportion of benign salivary tumors so far imported. In the Scottish series, 88.7 % of parotid tumors were benign compared with 51.9% of the Canadian series. In the Canadian series from the submandibular glands, 21.2 % only were benign. Of the intra‐oral salivary tumors, 62.2 % from the Scottish series were benign compared with only 34.7 % from the Canadian series.
Ultrastructure of glycogen‐rich clear cell carcinoma of the palate
Authors: Mohamed Abdel H.
Published: April 2006

Abstract. Tissues from four local recurrences of a palatal tumor and regional lymph node metastases were studied by light microscopy while ultrastructural observations were made on the most recent tumor. The tumor was composed of solid sheets, clumps, and small nests of polyhedral epithelial cells with well‐defined cell boundaries, clear cytoplasm, and cellular pleomorphism. Histochemical stains indicated the presence of abundant intracellular glycogen deposits in all tumor specimens examined. Ultrastructural observations revealed solid sheets of epithelial cells which lacked both surrounding basement lamina and ductal arrangements. The cytoplasm of the tumor cells was filled with P glycogen deposits and contained scattered bundles of tonofilaments and scant organelles. The transition between the glycogen‐rich tumor cells and surface epithelium showed intervening cells which contained diffusely dispersed ribosomes and small amounts of glycogen. The tumor probably originated from surface epithelium.
The Ultrastructure of Oral Neuromas in Multiple Mucosal Neuromas, Pheochromocytoma, Medullary Thyroid Carcinoma Syndrome
Authors: Miller R. L. , Burzynski N. J. , Giammara B. L.
Published: April 2006

The ultrastructure of oral neuromas from 2 patients with multiple mucosal neuromas, pheochromocytoma, medullary thyroid carcinoma syndrome reveals numerous hypertrophic unmyelinated and myelinated axons, hyperplastic neurilemmal cells and associated collagen fiber formation. These tumors are described and compared ultrastructurally with neurilemomas and neurofibromas as described by other authors. On the basis of this comparison, these tumors are not considered to be of neurilemmal origin. On the basis of light and electron microscopic histology it is postulated that these tumors represent hypertrophy of axons similar to that noted in amputation neuromas.
Estimation of the volumes of multinucleate giant cells
Authors: Abrams Basil , Shear Mervyn
Published: April 2006

Abstract An estimation of the volumes of three multinucleate giant cells has been attempted by measurements of the areas of enlarged tracings of serial paraffin sections through each of the cells; and by measurements of the thickness of the sections which was estimated at approximately 5 μm in scanning electron‐micrographs. In addition, three‐dimensional models of these tracings constructed in wax were used to estimate the volumes of the same cells by means of Archimedes' Principle. The results indicate a close correlation between the estimates derived from the two procedures and suggest that the three cells measured have a volume of the order of magnitude of 50,000 to 100,000 μm3.
Histochemical study of labial salivary glands in Sjögren's Syndrome
Authors: Fava‐De‐Moraes F. , Friedman H. , Egami M. I. , Bevilacqua E. M. A. F. , Cossermelli W.
Published: April 2006

Abstract Human labial salivary gland biopsies of patients presenting connective tissue diseases associated with Sjögren's syndrome were submitted to a polysaccharide histochemistry study. The normal acinar secretion is an association of neutral polysaccharides with a sulphosialomucin. In Sjögren's syndrome, there is a great reduction in the secretory activity of the acinar cells, but no qualitative change was observed. The pathogenesis of this decreased production and its importance regarding the clinical manifestations of Sjögren's syndrome are discussed.
Odontoblast metabolism in rats deficient in vitamin D and calcium, III. Protein synthesis in vitro
Authors: Engström C. , Jontell M. , Linde A.
Published: April 2006

Abstract Dentinogenically active rat incisor odontoblasts were dissected out from animals fed a low calcium, vitamin D free diet (R 25). Protein synthesis by these cells was studied by means of short‐time incubation in an in vitro system in the presence of the radioactive labeled precursors L‐leucine, L‐fucose and L‐proline. A significantly increased leucine and proline incorporation into the protein synthesized was noted in the cells from rats fed the deficient R 25 diet compared with odontoblasts from rats fed an adequate control diet (R 47). No difference between the two groups was found when fucose was utilized as a precursor. The well known increase in predentin width when feeding a rachitogenic diet may thus be explained by an increase in organic matrix synthesis in addition to the Possible negative direct effects of lowered serum Ca content. Prior to this study, the behavior of Proline as a precursor in the in vitro system was studied. The possibility of separating leucine‐labeled Proteins synthesized in the in vitro system by means of SDS‐polyacrylamide gel electrophoresis was also shown.
The prevalence of consolidated salivary deposits in the small ducts of human submandibular glands
Authors: Scott John
Published: April 2006

Abstract. Deposits of apparently solid material were observed in the small salivary ducts in a series of non‐diseased submandibular glands obtained from necropsies evenly divided by sex and adult age. The deposits were of granular or laminated structure. They were of mixed staining, the majority being predominantly eosinophilic. A small number of deposits were essentially wholly hematoxylinophilic and some of these were probably calcified. The prevalence of deposits, expressed as the number per unit sectional area, increased steadily with increasing age but was unrelated to sex. An apparently close correlation between intraductal salivary deposits and foci of obstructive adenitis in the same series of glands was shown to be mainly due to the common influence of age.

The deposits probably form by precipitation of salivary glycoprotein, possibly because of parenchymal age changes. They may be related to early salivary lithogenesis but the statistical evidence of this study suggests that they are unlikely to be a major factor in the etiology of focal obstructive adenitis.
The significance of alterations of pulpal respiration
Authors: Biestereeld Robert C. , Taintor Jerry F. , Marsh Connell L.
Published: April 2006

Abstract. Several methods of assessing pulpal injury due to cavity preparation and cytotoxic properties of restorative materials have been developed by previous investigators. Seldom in the literature are the mechanisms of these injuries considered beyond the histological level. This article examines pulpal injury on an ultrastructural and biochemical basis.
Basal cell extensions in human oral mucosa
Authors: King R. E. , Altini M. , Shear M.
Published: April 2006

Abstract. Basal cell extensions have frequently been observed in a variety of odontogenic lesions as well as in the fibrous epulis (fibrous hyperplasia of the gingiva). In order to determine the frequency of these extensions in normal human oral mucosa, a study using autopsy and surgical material was conducted. The results indicated that a specific type of rete ridge morphology exists for gingiva, including the presence of thin double stranded extensions which may be related to the functional role of the gingiva or to the fact that the odontogenic apparatus is derived from surface epithelium in this region in the developing embryo, or both. Similar extensions have not been found in other oral epithelia.
DNA‐ploidy rates in oral leukoplakias determined by flow‐cytometry
Authors: Grässell‐Pietrusky R. , Delinlein E. , Hornstein O. P.
Published: April 2006

In 11 patients with histologically confirmed benign (n = 4) precancerous (n = 7) oral leukoplakias, the nuclear DNA distribution patterns were analyzed by flow‐cytometry. In two of three precancerous lesions exhibiting severe dysplasia, monoclonal hyperdiploid (aneuploid) cell populations were demonstrated. Aneuploidy was not observed in early or moderate dysplasias. To fully assess the diagnostic significance of flow cytometry in oral premalignancies, a larger quantity of specimens must be examined.
Condylar pathology in jaw dysfunction: a semi‐quantitative study
Authors: Slootweg P. J. , de Wilde P. C. M.
Published: April 2006

The purpose of the study was to determine whether there was any correlation between temporomandibular joint (TMJ) dysfunction and structure of the mandibular condyle. Condyli from 11 patients with TMJ dysfunction were compared with condyli from 13 patients with clinically uninvolved joints. The following histologic aspects were studied: thickness of the articular soft tissue layer; presence of undifferentiated mesenchyme; progressive and regressive remodelling; and arthrosis, features that are thought to reflect the functional load to the articular surfaces. The only difference between both groups was a higher frequency of regressive remodelling in the condyli from dysfunctioning joints. No significant differences were observed with respect to the other histologic features. It seems that mechanical stress to the joint surfaces docs not play a predominant role as a cause of clinical TMJ complaints.
Ultrastructural findings of muscle degeneration in oral submucous fibrosis
Authors: El‐Labban N. G. , Canniff J. P.
Published: April 2006

Muscle changes were investigated ultrastructurally in 2 groups of patients having oral submucous fibrosis. One group was from patients with no evidence of restricted mouth opening and the other was from patients with restricted mouth opening. Electronmicroscopically, the majority of muscle fibres taken from the first group appeared normal with only occasional muscle fibres showing accumulation of homogeneous material and compression of the sarcomeres closest to this material. In contrast, the tissues from patients with restricted mouth opening showed severe changes and necrosis in a high proportion of muscle fibres. The necrotic muscle fibres exhibited complete loss of their plasma membrane, but in which the outline was maintained by an intact basal lamina. It is suggested from this study that restricted mouth opening in submucous fibrosis might depend not only on the sub‐epithelial fibrosis but also on the extent of muscle degeneration.
Human pulpal response to composite resin restorations
Authors: Leidal T. Ingar , Eriksen Harald M.
Published: April 2006

Abstract Composite resin restorations were placed in experimentally prepared cavities in human teeth. Various antibacterial regimens were used and the pulpal responses were studied and correlated with presence of bacteria on the cavity walls. Presence of bacteria seemed to be an important, but not the only reason for harmful pulpal responses. Good pulp protection was obtained by using a calcium hydroxide‐containing base material after acid etching of cavities was carried out. The present results were compared with those from an identical study in monkeys, and good correlation was found.
Thermal trauma to teeth
Authors: Spierings Th. M. , Peters M. C. R. B. , Plasschaert A. J. M.
Published: April 2006

Abstract The literature is reviewed with respect to several thermal loading situations and their influence on the temperature field in teeth. Breathing, food consumption, and dental treatment are processes disturbing the thermal balance in the oral cavity. The tooth temperature will be affected. These thermal changes result in a physical after‐effect on enamel, dentin, and restorative materials, as well as in a histological change of the pulp tissue. Postoperative discomfort is another after‐effect reported as a result of dental treatment. Recommendations concerning cooling technique and the use of a cement base are given to avoid this discomfort.

In the literature reviewed, attention is mainly focused on temperature within teeth. However, the underlying thermal processes are important in the reported after‐effects. It is concluded that more attention should be paid to this phenomenon in future research.
Suitability of controlled release delivery system for root canal disinfection
Authors: Barnett Frederic , Trope Martin , Kreshtool Daniel , Tronstad Leif
Published: April 2006

Abstract The purpose of the present study was to assess the bacteriologic status of the root canal after disinfection with a quaternary ammonium compound in a controlled release system. Root canal infection was induced in 57 single root teeth in dogs. The canals were then instrumented under aseptic conditions and irrigated with sodium hypochlorite and sterile saline. After the instrumentation, 10 canals were treated with the quaternary ammonium compound in the controlled release system, 9 canals with the quaternary ammonium compound on a cotton pellet, 10 canals with formocresol, 10 canals with a paste of calcium hydroxide. In 18 canals, no intracanal medicament was used. Bacteriologic samples were taken after 14 days using an anaerobic technique. The results indicated that the quaternary ammonium compound in the controlled release system was as effective as formocresol and calcium hydroxide in rendering the root canal free of bacteria. The advantages of an antiseptic with a long‐lasting effect for the elimination of bacteria from the root canal and for the prevention of culture reversals were stressed.
Relationship between pulp dimensions and development of pulp necrosis after luxation injuries in the permanent dentition
Authors: Andreasen F. M. , Zhijie Yu , Thomsen Birthe Lykke
Published: April 2006

Abstract A relationship between type of luxation injury, stage of root development and development of pulp necrosis after injury has been demonstrated. It was therefore decided to delve more deeply into the relationship between stage of root development and the later development of pulp necrosis after injury in a material of luxated permanent teeth. In this context, the diameter of the apical foramen and the distance from the apical foramen to the pulp horn, as measured on radiographs taken at the time of injury, were used as indicators of root development. In order to justify this approach, the precision of the measuring technique and the accuracy of the radiographic technique were studied. Regarding precision of the measuring technique, it was found that there was a 1% to 4.3% error of the means of all measurements for the various parameters and exposure techniques employed. With respect to accuracy of the radiographic technique, it was found that there was a systematic error in the radio‐graphic technique which resulted in a median relative distortion of between 3.5% and 8% image magnification for the various parameters and the exposure techniques employed. These findings indicated that the measuring technique employed in the present investigation was reliable for studying the parameters in question. In a material of 226 extruded, intruded and laterally luxated maxillary permanent incisors, observed for up to 10 years, it was found that the development of pulp necrosis after injury was significantly related to the diameter of the apical foramen. For extruded and laterally luxated teeth, the smaller the diameter, the greater the probability of pulp necrosis. Intruded teeth with incomplete root development (i.e. radiographic diameters ≥1.2 mm) were associated with a much higher probability of pulp survival than teeth with complete root development (i.e. radiographic diameters ≤0.7 mm). The distance from the apical foramen to the pulp horn did not appear to be of importance in predicting pulp survival when diameter of the apical foramen was taken into account. Pulp survival after luxation injuries with displacement thus appears to be dependent upon the size of apical contact between the pulp and the periodontium.
Book Review
Authors: Quinn Peter D.
Published: April 2006

Books reviewed in this articles:

William H. Ball: Surgical Correction of Dentofacial Deformities
The ischemic infarct pulp of traumatized teeth: A light and electron microscopic study
Authors: Cipriano Thomas J. , Walton Richard E.
Published: April 2006

Abstract Extirpated pulps from 42 traumatized, asymptomatic teeth with no history of periapical pathosis, pulp exposure, or responsiveness to pulp tests were examined by light microscopic techniques. Only 5 pulps demonstrated infarcts; these were further evaluated with the transmission electron microscope. Eight microscopically, as compared lo the normal controls, the pulp tissue of the so‐called ischemic infarct was markedly altered. Some areas showed inflammation and altered nuclei, but with no discernible neural elements, and with less collagen. The electron microscopic samples showed evidence of necrosis, pal‐terns of nuclear degradation, relative avascularity, degenerating neural elements, and disorganized collagen. It was concluded that the ischemic in fan; l phenomenon in the traumatized pulp docs occur occasionally, but presents a variety of structural alterations indicating degeneration.
Radiographic assessment of simulated root resorption cavities
Authors: Andreasen F. M. , Sewerin I. , Mandel U. , Andreasen J. O.
Published: April 2006

Abstract A study into the sensitivity and accuracy of a standardized radiographic technique for the disclosure of root resorption cavities was performed in a cadaver material. Film contrast and horizontal angulation were varied in order to identify factors in radiographic exposure which resulted in the greatest diagnostic reliability. In an autopsy material of 5 jaw blocks containing both mandibular premolars, “small, medium and large” cavities simulating root resorptions of 0.6, 1.2 and 1.8 mm in diameter and 0.3, 0.6 and 0.9 mm in depth, respectively, were drilled at the cervical, middle and apical thirds of the proximal and oral root surfaces of the premolars. Cavity locations were distributed to ensure an equal number of locations with and without cavities and an equal number of cavities of each size. Results of the investigation indicated that the small cavities were never visualized, nor were 6 out of 13 medium cavities nor 1 out of 13 large cavities; that cavities located proximally were more readily seen than those located orally and that there was no clif Terence in cavity visualization between cavities on the apical, middle or cervical thirds of the roots; high density (contrast) films allowed the best cavity visualization. Finally, radiographs from the time of injury (i.e. preresorption radiographs) as well as radiographs taken at various horizontal angulations were found to be of importance in order to increase the possibility of cavity visualization.
Blood loss during endodontic surgery
Authors: Selim Hassan A. , El Deeb Mahmoud E. , Messer Harold H.
Published: April 2006

Abstract The volume of blood lost during endodontic surgery was measured for 60 patients undergoing routine surgical procedures using local anesthesia. Blood loss averaged 9.5 ml for all patients, with a range of 1.2 to 48.4 ml. Operating time was the major variable influencing blood loss; the rate of blood loss correlated very strongly (r = 0.86) with duration of surgery. Other than palatal surgery of maxillary molars, differences in blood loss associated with different teeth were small. Endodontic surgery on any teeth in either arch was far below the level at which fluid replacement therapy might be considered, and was comparable to loss during single tooth extractions.
Mixed anaerobic periapical infection with sinus tract
Authors: Haapasalo Markus , Ranta Kari , Ranta Helena
Published: April 2006

Abstract A complicated periapical infection of a right lateral maxillary incisor is reported. Conservative treatment including standardized mechanical preparation and local medication with calcium hydroxide was not successful. Neither was directed antibiotic therapy effective in eliminating the infection. Periapical surgery was performed and the healing proceeded uneventfully. Bacteria were isolated both from the root canal and the periapical lesion. The findings are discussed in relation to phagocytosis and bacterial synergism.
Primary teeth traumatic injuries at a private pediatric dental center
Authors: Garcia‐Godoy Franklin , Garcia‐Godoy Federico , Garcia‐Godoy Federico M.
Published: April 2006

Abstract The purpose of this study was to analyze primary teeth traumatic injuries at a private pediatric dental center. A total of 114 children with 196 traumatized teeth participated in this study from 1980–1984. The most common injury was concussion. The 1–2 year olds presented the highest number of injuries (p<0.01). Falling against an object was the most common cause of injury in both sexes. Most of the injuries occurred inside the home. July and August were the months that showed the highest number of children with injured teeth; 38.7% of the children visited the dental office the same day of the injury, while 37.8% did so 1–7 days later.
Root form and canal anatomy of maxillary 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 root form and canal anatomy has not been established. Features of root and root canal morphology that occur at particularly high frequency in Mongoloid populations have not been systematically documented, and the implications that such features may have upon clinical endodontics have not been fully reported. In this study 100 maxillary first premolars 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. Sixty per cent of the maxillary first premolars examined were found to be single‐rooted, but only 13% were found to have a single canal. The high frequency of single‐rooted teeth with two canals suggests that the single‐rooted condition represents a fusion, occurring in the relatively recent past, of two original roots.
An atypical tooth fracture due to an indirect trauma mechanism
Authors: Oikarinen Kyösti
Published: April 2006

Abstract This report presents a crown‐root fracture of a lower premolar due to an indirect trauma mechanism. Violent closure of the teeth was caused when the patient hit his chin on hard ground after a fall from a bicycle. The fact that a lower premolar was injured is suggested to be due to the tooth involved having had abnormal anatomy of the root. Angulation in the root configuration makes the tooth act like an ankylotic one, which means decreased capacity to resist sudden occlusal forces.
Decision strategies in endodontics: on the design of a recall program
Authors: Reit Glaes
Published: April 2006

Abstract In order to diagnose periapical pathosis in endodontically treated teeth, a recall program based on clinical and radio‐graphic examination has to be established. Since different observation periods have been recommended before treatment results are classified as successes and failures, various approaches to such programs are possible. However, substantial interindividual variations have been demonstrated in radiographic diagnosis of periapical disease. Therefore, in the present study 2 diagnostic criteria were used within each program. The recall strategies were evaluated using formal decision analysis and cost‐effectiveness analysis. This investigation showed that the best strategy would be to examine the patients 1 year after endodontic treatment. Patients with clinical and/or radiographic signs of periapical disease would be re‐examined 3 years later. At this point any suspicion of periapical pathosis would lead to re‐treatment of the tooth.
Experimental dental traumatology: development of a model for external root resorption
Authors: Andreasen J. O.
Published: April 2006

Abstract Intentional replantation of teeth appears to be a suitable model for examining the etiology and pathogenesis of root resorption elicited after traumatic dental injury. A histomorphometric analysis of root resorption developed with this model is described. An analysis of the accuracy and precision of the method in replanted monkey incisors has demonstrated that the method is usually reliable in revealing the extent and type of root resorption. In some experimental circumstances, however, where the pulp status was not controlled by endodontic therapy, a large intra‐ and interanimal variation was found in the extent of root resorption. Apart from a relation to tooth maturation and tooth type (incisors versus molars), this variation was primarily caused by haphazard occurrence and extent of inflammatory resorption. Based on an analysis of a series of experimental replantation studies, the following guidelines for experimental design seem appropriate: 1) selection of teeth according to identical tooth development and pulp status (i.e. intact, extirpated or root‐canal‐treated); 2) use of a standardized extraction procedure; 3) consideration of the type of teeth included (i.e. molars vs. incisors), unless paired experiments are planned or the experimental design includes an equal number of incisors and molars allotted to the different experimental groups; 4) side differences (right vs. left side) are apparently of no or minor importance; 5) sex differences are apparently of no or minor importance; 6) an individual proneness to resorption is apparently of no or minor importance, which means that more than one tooth can be used in each animal. The experimental design thus does not dictate the use of paired (i.e. homologous) teeth. However, as a matter of safety, when small differences in healing are expected, paired observations should be used.
Evaluation of statistics and desirable experimental design of a histomorphometrical method for studies of root resorption
Authors: Andersson Lars , Jonsson Björn G. , Hammarström Lars , Blomlöf Leif , Andreasen Jens Ove , Lindskog Sven
Published: April 2006

Abstract This study characterizes how the accuracy and precision of estimates of the true extent of root resorption are influenced when measuring serial‐sectioned individual teeth; different types of teeth with different degrees of resorption, sampling different numbers of sections and registration points. Maxillary and mandibular central and lateral incisors can be used for studies of root resorption with this method. Eight points of registration were required for every section when smaller differences in the means of root resorption between experimental groups were expected. When comparing groups with extensive differences, 4 points of registration were enough. The points should be labial, lingual, mesial and distal. Ten to 17 sections per tooth seemed to be sufficient in most instances. The number of experimental animals needed depended on the statistical procedures and expected outcome of the experiment.
Pulpal calcifications in patients with coronary atherosclerosis
Authors: de Moura Abilio Albuquerque Maranhäo , de Paiva José Gustavo
Published: April 2006

Abstract Our objective was to investigate the occurrence of free pulpal calcifications in the pulpal chamber of teeth of patients suffering from coronary alterations. The incidence of denticles was higher in patients with coronary atherosclerosis than in patients who did not suffer from this disease. Moreover, patients suffering from coronary atherosclerosis presented a higher number of teeth with pulpal calcifications than patients in the control group.
Effect of Dycal® on dentin permeability
Authors: Tao Liwen , Reynolds J. Marvin , Pashley David H.
Published: April 2006

Abstract The ability of 3 formulations of a hard‐setting calcium hydroxide‐containng base material (Dycal®) to seal dentinal tubules was evaluated in an in vitro model. The latest light‐cured generation of the material was clearly superior to the previous formulations at all time periods tested.
Effect of concentrated hydrogen peroxide solution on the surface morphology of cut human dentin
Authors: Titley K. , Torneck C. D. , Smith D. C.
Published: April 2006

Abstract The effect of concentrated hydrogen peroxide solution, alone and in combination with acid‐etching with 37% phosphoric acid for 60 s, on the surface morphology of cut human dentin was investigated by SEM and compared to controls in which saline solution rather than hydrogen peroxide solution was used. Examination of the specimens revealed that the smear layer on the surface of cut dentin was not removed by hydrogen peroxide alone, and that a dense amorphous precipitate was formed on the surface of the smear layer after extended exposure. The precipitate accumulation was first noted after 20 min of exposure. Examination of the dentin after hydrogen peroxide exposure followed by acid‐etching revealed the presence of a fine granular deposit on an otherwise clean dentin surface. A modest amount of amorphous precipitate was seen over the entire dentin surface after 60 min of hydrogen peroxide exposure. Examination of specimens that were acid‐etched before being exposed to hydrogen peroxide indicated that the smear layer was effectively removed and the orifices of the dentinal tubules were enlarged to permit more effective penetration of the peroxide solution. It also resulted in less accumulation of precipitate on the dentin surface than the other methods.
Quantitative chemical study of root canal preparations with calcium hydroxide
Authors: Cohen Florence , Lasfargues Jean‐Jacques
Published: April 2006

Abstract Chemical tests were carried out in order to determine the rate of carbonatation of different samples of calcium hydroxide used in intracanal therapeutics. The methods were based either on direct measurement of the kinetics of CO2 fixation by dry powder or on analytical titration of the carbonate content of fresh and aged samples. Dry powder preserved in closed flasks and paste preparations packed in screw syringes were free from carbonate even after several years. When samples were exposed to open air the rate of carbonatation was extremely slow. The carbonate formation in normal clinical conditions of calcium hydroxide utilization seemed not to be responsible for the variability sometimes observed in clinical results.