bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of various factors on the rate of phosphate precipitation in an inorganic solution and in saliva
Authors: Mukherjee S.
Published: July 2006

The rate of precipitation of phosphate in an inorganic solution and in saliva was studied under various conditions by a method previously described using32P as a tracer.

The results with inorganic solution showed that an increase in calcium had a greater effect on the precipitation rate than an increase in phosphate concentration. The pH had its most significant effect near 8.0. Magnesium and fluorine had no effect at the concentrations tested. Pyrophosphate at a concentration above 0.125 mM caused precipitation of calcium pyrophosphate and decreased the rate of orthophosphate precipitation when the solution contained 2mM calcium but not when this was 1 mM. An increase in viscosity of the solution to the level of saliva had an insignificant effect.

In saliva an increase in calcium or phosphate or pH caused a rise in precipitation rate. This was observed at concentrations of calcium or phosphate exceeding 0.25 mM for both. The addition of CO2had no significant effect, as was the case for ammonia, urease and pronase. Pyrophosphate at higher concentration (0.4 mM) caused a reduction in precipitation rate. The presence of dental or artificial plaque material or filtration of saliva caused an increase in the precipitation rate.

In the Discussion efforts are made to explain most of the findings. It is pointed out that the estimation of salivary calcium and phosphate should be a valuable diagnostic test and that salivary calcium and phosphate may be related to the general calcium phosphate balance of the individual.
Microvascular changes in cheek‐pouch wounds of oophorectomized hamsters following intramuscular injections of female sex hormones
Authors: Lindhe Jan , Brånemark P‐I , Birch John
Published: July 2006

The increased degree of gingivitis during pregnancy may be ascribed to both the influence of bacterial plaque and the action of sex hormones on the microvascular system. The present investigation was undertaken to elucidate the mechanism behind the changes in vascular structure and function in healthy and in slightly inflamed tissues following an increased blood concentration of estrogens, progesterone and chorionic gonadotropin. The cheek‐pouch of oophorectomized female hamsters constituted the experimental model. The animals were oophorectomized 7 days prior to the start of the hormone experiments. A micro‐wound was produced surgically in the cheek‐pouch to leave a defect area with a slightly damaged vascular bed and a surrounding tissue with unaffected circulation as observed by vital microscopy. Irrigation with Tyrode's solution for 10–15 minutes reversed the inflammatory changes in the defect area. A hormone solution (0.2 ml of 5 mg /ml StilbolR or progesteroneR or 0.2 ml of 1,500 I.U./ml GonadexR) was injected intramuscularly in the hamster's hind leg either once (short term experiments) or daily during a five day period (long term experiments). Estrogen and chorionic gonadotropin caused only minor vascular changes. When progesterone was added to the circulating blood via the hind leg muscle, the resistance of the wound tissue seemed to be lowered and acute inflammation developed in the defect area. The surrounding tissue was unaffected. The symptoms of Inflammation in the wound were more severe than immediately after the surgical procedure as judged by the degree of swelling of the endothelium lining the veins, the number of leucocytes adhering to the vessel walls and the number of micro‐thrombi. The findings are discussed in the light of present knowledge of the effects of female sex hormones on intra vascular and perivascular cell structure and function.
The basal cell layer of the developing oral mucosa in the human fetus
Authors: Coslet J. George , Cohen D. Walter
Published: July 2006

The dense fibrous periosteum of the developing mandibular and maxillary alveolar bones is continuous with the dense collagenous connective tissue of the gum ridge. The polarized columnar basal cell of the gum ridge epithelium is always intimately associated with the dense connective tissue. Cytoplasmic extensions of these cells are seen to penetrate into the connective tissue. Fine reticular fibers appear to connect the cytoplasmic extensions of the basal cell with the dense collagen bundles of the connective tissue. A similar condition prevails in the hard palate between the basal cell of the epithelium and the periosteum of the palatine bone. The connective tissue of the lip, cheek and soft palate is loosely arranged. The epithelial‐connective tissue junction of the cuboidal cell is smooth. Some fine reticular fibers are seen to connect the layer of the epithelium to the sheath of striated muscle fibers.
A two‐year comparison of hand and electric toothbrushes
Authors: Mc Kendrick A. J. W. , Barbenel L. M. H. , Mc Hugh W. D.
Published: July 2006

A controlled study was carried out on 103 dentally‐oriented university students to compare the effects of hand and electric toothbrushing. The study lasted two years. Subjects were examined at the beginning, and 3, 6, 12 and 24 months later. Oral debris and calculus formation were assessed by a modification of Greene and Vermillion's (1960) methods, and gingivitis and periodontitis by Russell's (1956) technique. Half of the subjects using the electric brushes and half of those using hand brushes were instructed how to brush; the others were not.

No significant differences in oral debris or calculus formation, in gingivitis and periodontitis, or in gingival recession were found between any of the groups at any stage in the study. It is concluded that the electric brush is not superior to the hand brush when used by dentally‐oriented young adults.
The state of calcium and phosphate in saliva
Authors: Mukherjee S.
Published: July 2006

The present knowledge on the state of calcium and phosphate in saliva has been reviewed.

Ultrafiltration studies showed that a part of the calcium + magnesium and phosphate in saliva is non‐ultrafiltrable. On an average 9% of the non‐ultrafiltrable phosphate and 23% of the nonultrafiltrable calcium + magnesium was found to be due to precipitation under the conditions of the experiment. Ultrafiltration carried out under 7.5% CO2 in air had a similar effect on the ultrafiltrability of calcium and phosphate as acidification by hydrochloric acid to the same pH. A viscosity reducing enzyme, pronase, had no significant effect. All the phosphate became ultrafiltrable when the pH was reduced below 5.5. Significant reduction in ultrafiltrable calcium and phosphate was observed when the pH was increased from 6.9 to 7.5, but not when this was further increased to 8.0.

Gel filtration chromatography carried out through a column of G 100 Sephadex showed that all calcium and phosphorus was associated with relatively low‐molecular material. The UV absorption criteria and the dialyzable nature of the substance indicated that this was probably non‐protein in nature. Further work on the identification of this material is in progress.
Periodontal disease in dogs
Authors: Gad Torben
Published: July 2006

The object of this investigation was to evaluate the prevalence and etiology of periodontal discase in dogs. The material comprised 62 dogs with an age range from three months to twelve years. Periodontal disease was registered by means of Russell's Periodontal Index and debris and calculus by Greene and Vermillion's Oral Hygiene Index. The following results were obtained: 1. Periodontal disease, debris and calculus were found in 97 % of dogs and showed a statistically significant increase with age. 2. Both calculus and deposits of debris on the teeth had a statistically significant, independent effect on the severity of periodontal disease. 3. Periodontal destruction occurs approximately five times faster in dogs than in humans. However, this may be explained by the greater amounts of deposits on the teeth of dogs.
Epithelial changes in gingivitis
Authors: Thilander Holger
Published: July 2006

The changes in epithelial structure due to inflammation were studied with the electron microscope. The material comprised biopsies from inflamed gingivae in 12 adult patients. The first change noticed in the epithelium was a widening of the intercellular spaces. When the widening was of moderate degree intermediate junctions, tight junctions and desmosomes were still observed. With increased widening the intermediate junctions disappeared first, then the tight junctions and, as a subsequent change there was a reduction in the number of the desmosomes. Leucocytes of different types were often present between the epithelial cells. In some areas, the lamina densa was diffuse or completely absent. Whether this was a real breakdown or an artefact is difficult to decide. In the cytoplasm of the epithelial cells there were numerous glycogen granules and swollen mitochondria with reduced numbers of cristae.

More advanced changes consisted of localised disintegration of cytoplasm and other changes of the type that precede cell death. The possible effects of these morphological changes upon epithelial permeability are discussed.
Melanin containing organelles in cells of the human gingiva I. Epithelial Melanocytes
Authors: Schroeder Hubert E.
Published: July 2006

Biopsies of the marginal gingiva obtained from 21 caucasoid subjects (average age of 25 years) served for the electron microscopic examination of epithelial melanocytes and their organelles. In 60 to 70 per cent of the subjects, melanin producing dendritic melanocytes could be observed within the stratum basale and the suprabasal stratum spinosum. Electron microscopically, 2 types of structurally different melanocytes could be distinguished: inactive, and actively premelanosomes producing and melanin synthesizing cells. The number of premelanosomes and melanosomes per cytoplasmic unit area of melanocyte projections increased towards their peripheral termination. The developmental stages of possibly two structurally different premelanosomes are described to be comparable to those of the human skin. Fully melanized ovoid melanosomes were measured to be 0.27±0.06 micron long and 0.10±0.04 micron wide. Striated bars inside premelanosomes are suggested to represent a tightly coiled spiral possibly reflecting the molecular arrangement of tyrosinase. The findings are discussed with reference to the knowledge of melanocytes, premelanosomes and melanosomes in human skin, hair bulbs and melanomatous tissues.
Principal fibres of the periodontium
Authors: Smukler H. , Dreyer C. J.
Published: July 2006

The arrangement of the principal fibres of the periodontium of the Vervet monkey was investigated. This study indicates that the cemento‐gingival fibres, radiate out from the cementum of the teeth in much the same way as do the cemento‐alveolar fibres. The radiating cementogingival fibres which terminate in the cementum of the adjacent teeth are responsible for the presence of the trans‐septal band which has been described as a distinct fibre group. Other cemento‐gingival fibres decussate with similar fibres from adjacent teeth. In labio‐lingual sections, these decussations give rise to the appearance of cross‐sectional fibres within the longitudinally orientated masses. These cross‐sectional bundles have been described as a separate fibre system known as the circular band. Certain of these radially arranged cemento‐gingival fibres terminate in muscle fibres of the facial musculature. This continuity is well demonstrated in sections which traverse the mucobuccal fold. The significance of the radial arrangement of fibres of the periodontium and the relationship of cemento‐gingival fibres to the facial musculature is discussed.
An in vitro study of anti‐calculus agents
Authors: Mukherjee S.
Published: July 2006

A number of chemicals that could dissolve the organic part of the dental calculus or its inorganic salts were tested in vitro as possible anti‐calculus agents. Several of them were tried in combination. The effect was studied for five and ten minutes on finely meshed calculus, dentine and enamel.

None of the chemicals tested, either alone or in combination with another chemical, had a selective effect on calculus. On the basis of total weight, dentine was often dissolved to a greater extent than calculus, although the percentage of total phosphorus dissolved was greatest for calculus. Organic solvents always showed a low dissolution effect. However, Ascoxal at pH 4.5–5 showed a much greater effect on calculus than on dentine and enamel.
Mast cells of the human gingiva
Authors: Zachrisson Bjǒurn U.
Published: July 2006

One‐side gingivitis was induced in 21 individuals by local abolition of tooth cleansing for 15–17 days. Adjoining sections of biopsies from the non‐cleansing side as well as from the control side with good tooth cleansing were stained with toluidine blue (pH 1.0), acridine orange (pH 0.5), astra blue (pH 0.2—0.3), alcian blue‐safranin and the EACNAS‐GBC technique in order to demonstrate mast cells specifically. The clinically normal gingiva was found to be rich in mast cells. In the inflamed tissue, the number was increased, especially in the pocket area of the connective tissue. The difference was due to an increase of both mature and, particularly, of immature mast cells. In those cases, where the inflammatory infiltrates were heavy, however, the number of mast cells was reduced in the area of cellular infiltration. The results indicate that products from the bacterial plaque at the gingival margin may directly or indirectly induce proliferation of mast cells in the adjacent connective tissue. Above a certain degree of stress, however the mast cells may respond by degranulation and release their active substances, which by contributing to the inflammatory reaction may enhance the local resistance.
The effect of deficiencies of calcium, vitamin D or calcium and vitamin D and of variations in the source of dietary protein on the supporting tissues of the rat molar
Authors: Oliver W. M.
Published: July 2006

An histological investigation has been carried out on the periodontal tissues of young rats fed for eight weeks on diets deficient either in calcium (calcium content 0.026 per cent; calcium to phosphorus ratio 0.058), vitamin D, or calcium and vitamin D, in which protein was supplied either as blood albumen or egg albumen.

When the diet contained blood albumen, the deficiency of calcium resulted in alveolar changes resembling osteoporosis and in a reduction in the number and diameter of the fibres of the periodontal ligament. When the diet contained blood albumen, the deficiency of calcium and vitamin D caused alveolar changes resembling osteoporosis and a reduction in the number and diameter of the fibres of the periodontal ligament. The deficiency of vitamin D had no obvious effect on the periodontal tissues of the rat. The substitution of egg albumen for the blood albumen in the diets intensified the osteoporotic changes caused by the deffciency of calcium. In rats deficient in calcium and vitamin D it superimposed an osteomalacic change, resulting in a condition of the alveolar process which resembled a combination of osteomalacia and osteoporosis. It also increased the incidence of areas of resorption of primary cementum in all dietary groups. The cementoid on the surface of secondary cementum behaved under these conditions of dietary stress in the same way as the osteoid. The manner in which the dietary deficiencies may produce these changes is discussed.
The uptake of H3 proline in the guinea pig gingiva and palate
Authors: Buck Douglas
Published: July 2006

Keratinization is a complex process and at present only incompletely understood. This series of experiments demonstrates the uptake of H3 proline and subsequent appearance of a radioautographic label six to twelve hours later in the keratin of the guinea pig gingiva and palate. Furthermore, the label is lost between day four and day five. The negative result of externally applied H3 proline on the palate rules out external diffusion confirming that at least a portion of the keratin is proline derived.
Physiologic stress and tooth contact
Authors: Butler James H. , Stallard Richard E.
Published: July 2006

This investigation was undertaken to study the relationship between physiologic data, such as pulse rate and stroke volume, to the occurrence of tooth contacts. The tooth contacts were monitored in the intercuspal (I.C.) position and lateral or eccentric to this position with the aid of radio‐transmitters constructed into dental bridgework as described by Kavanagh and Zander (1965), and Butler and Zander (1968). The frequency and duration of tooth contacts during mastication and swallowing observed was not different from previous investigations (Graf and Zander 1963, Adams and Zander 1965). Under varied environmental situations, however, tooth contacts lasting up to 17 seconds were observed occurring with accompanying alteration in the pulse rate‐stroke volume data. These periods of clenching or bruxing type contacts were directly related to periods of emotional reactions, stress and/or anxiety.
The molecular size of enzymes from dental plaque material
Authors: Söder Per‐Östen
Published: July 2006

Amylase, proteases and hyaluronidases were separated from dental plaque material with the aid of gel filtration on Sephadex G‐100 and G‐200. The filtration values of these enzymes were compared to those of proteins of known molecular weight. Good agreement was found between the values estimated from gel filtration and the known values.

The calculated values for the different enzymes in the dental plaque are:

The hyaluronidase, H1 > 300.000, H2∼200.000, H3∼150.000 and H4∼100.000. The proteases, PIIa∼40.000, PIIb∼23.000 and PIIc∼18.000. The amylase∼16.000.
A study of the periodontal state in two hundred and two skulls of primitive peoples
Authors: Davies D. M. , Picton D. C. A.
Published: July 2006

Using the method described previously the periodontal state of two hundred and two skulls was examined by calculating the Tooth Cervical Height Index. The skulls were selected from seventeen racial groups, detailed records being available concerning each skull. The attrition index modified from Davies and Pedersen (1955) and the calculus index (Ramfjord 1966) were also estimated. Multiple regression analysis revealed that TCH‐index was not dependent on the age, sex or body height. A significant dependence was shown, however, between TCH‐index and the calculus index, and between TCH‐index and the degree of attrition. The mean TCH‐index for one hundred and one skulls which had been found within fifty miles of the sea was 1.89 ± 0.47 while for one hundred and one skulls collected further inland was 2.98 ± 0.89; a significant dependence was detected in the analysis.
Melanin containing organelles in cells of the human gingiva
Authors: Schroeder Hubert E.
Published: July 2006

Biopsies of the marginal gingiva obtained from 21 caucasoid subjects (average age of 25 years) served for the electron microscopic examination of melanin containing organelles in keratinocytes of the oral epithelium. Basal and suprabasal keratinocytes situated at epithelial rete pegs of the free and attached gingiva were observed to contain granules of melanin representing premelanosomes as well as single and compound melanosomes. These organelles were either randomly distributed or preferentially located at the cell poles or arranged around the nucleus. Single melanosomes were 0.31 ± 0.08 micron long and 0.12 ± 0.04 micron wide. Compound melanosomes were areas, 0.36 ± 0.12 micron in diameter, bound by a unit membrane and containing numerous single melanosomes which in part appeared to dissolve in granules. There was a centrifugal transport of melanin containing organelles with advancing keratinocytes. Single and compound melanosomes were occasionally found in cells up to the upper stratum spinosum. The findings are discussed with regard to comparable observations as well as in connection with the prevailing theories of melanin transfer and degradation.
The primary immune response of mice to two submucosal antigens
Authors: Young W. G. , Dick H. M. , Trott J. R.
Published: July 2006

Within the limits of these experiments there appeared to be a difference in quality of the immune response of mice to Bovine Serum Albumin and Horse Ferritin. A primary injection of Bovine Serum Albumin in the mandibular labial sulcus was followed by cell replication and plasma cell differentiation in the cervical lymph nodes and a rise in serum antibody.

No similar quantitatively measurable cellular response was found in the cervical lymph nodes to a primary injection of Horse Ferritin in the same site, although detectable quantities of serum antibody were present in the same animals.
The effects of diets of different physical consistencies on the periodontal proliferative activity in young adult rats
Authors: Weiss R. , Stahl S. S. , Tonna E. A.
Published: July 2006

Twenty young adult male rats were divided into two groups of ten rats each and fed either a powder or pellet diet of identical content for a thirty day experimental period. One hour prior to sacrifice, each rat was given an intraperitoneal injection of 0.5uc of tritiated thymidine per gram of body weight. After sacrifice, the maxillae were dissected out and prepared for autoradiographic and histologic study.

Proliferative cellular activity was determined in the periodontal tissues of the maxillary first molars. Significantly higher activity was noted in the crestal epithelium and in the fibroblasts at the interradicular septum of the pellet fed rats when compared to powder fed animals. These elevated values may reflect tissue responses to the coarser consistency of the pellets.
Vestibular deepening by the technique of Edlan and Mejchar
Authors: Wade A. Bryan
Published: July 2006

Deepening of the inferior labial vestibule was undertaken according to the technique of Edlan and Mejchar on 25 patients aged 17–55 years (X =). Observations were made at intervals, the total period ranging from (X =). Mean vestibular depth before operation was 2.24 ± 0.15 and post‐operatively 6.96 ± 0.23, the difference of 4.72 mm. was statistically significant (P < 0.01). Pre‐operatively the gingival state on the labial aspect of the mandibular central incisors showed a mean value of 2.28 ± 0.36 units and 0.90 ± 0.20 units post‐operatively. The difference was statistically significant (P < 0.01). The Plaque Index pre‐operatively was 1.70 ± 0.31 and 0.88 ± 0.20 post‐operatively (difference ‐ significant: P < 0.05). The correlation coefficient between the plaque and gingivitis scores before operation, r =+0.36, and post‐operately, r =+ 0.43 suggests that there was a definite relation which was strengthened as a result of the operation. It is concluded that when there is only a limited amount or no gingival tissue on the labial aspect of the mandibular anterior teeth, but no pockets the technique provides a predictable way in which gingival health can be achieved and maintained.
The plaque‐inhibiting capacity of 11 antibacterial compounds
Authors: Gjermo Per , Lyche Baastad Kirsten , Rölla Gunnar
Published: July 2006

The plaque inhibiting effect in vivo of 11 antibacterial agents was compared with their antibacterial activity against salivary bacteria in vitro. The in vivo effect was tested for 4 days in a human model with a supplement of sucrose in the diet. The antibacterial activity of the compounds, which were chosen from different main groups of disinfectants (alcohols, iodophores, dyes, quaternary ammonium bases, amidines, guanidines) were tested in four in vitro systems. No correlation was evident between the in vivo and in vitro effects. Chlorhexidine gluconate and ‐acetate proved most effective in vivo, whereas several other substances equally or more effective against salivary bacteria in vitro, exhibited no effect in vivo. It is concluded that other factors than the antibacterial properties are important in plaque inhibition in vivo.
The development of the vascular bed of the marginal periodontium
Authors: Kindlová M.
Published: July 2006

The vascular bed of the periodontum of rat molars develops from the vascular network of the alveolar mucosa, from the vascular network of the enamel organ and from vessels which, with the development of roots, form the bed of the periodontal membrane. Although these vascular areas form a unity in a developed periodontium, they retain their differences in arrangement. During the formation of the enamel, the bed of the enamel organ is arranged in rat molars and in the permanently growing rat incisor according to the same principles. In both types of teeth, the principles of this arrangement correspond with the metabolic needs of amelogenesis.
A comparison of four epidemiological methods of assessing periodontal disease
Authors: Sheiham Aubrey , Striffler David F.
Published: July 2006

An epidemiological study of periodontal disease, using four methods of assessment of severity of periodontal disease, was conducted on a representative sample of 1,976 New Mexicans aged 18 to 44 years. Periodontal disease was assessed using PI and PDI and radiographic and mobility assessments. One objective of the study was to assess whether radiographic scores and measurements of clinical mobility added significantly to the precision of discrimination between the severity of periodontal disease in populations when using the PI and PDI. Findings indicated that the PI discriminated between population groups as efficiently as the PDI plus radiographic and mobility scores. In this study females had less severe periodontal disease than males; Anglos had less severe disease than Spanish‐Americans, Mexicans, American‐Indians, and Negroes; persons with a greater number of years of schooling and persons in the higher socioeconimic groups had less severe periodontal disease than persons with fewer years of schooling and in the lower socio‐economic groups respectively; urban and rural persons had a similar severity.
A comparison of four epidemiological methods of assessing periodontal disease
Authors: Sheiham Aubrey , Striffler David F.
Published: July 2006

Periodontal disease was assessed using PI and P.D.I. and radiographic and mobility assessments. Analysis of data by worst score in the mouth and by individual teeth indicated that PI did underestimate the severity of periodontal disease. P.D.I. diagnosed destructive periodontal disease in 45.0 per cent of mouths and 38 per cent of teeth considered free of destructive periodontal disease using PI. P.D.I. detects more destructive periodontal disease than PI at the lower radiographic scores (4 and 5); at radiographic scores 6 and 7 the disparity between the P.D.I. and PI decreased. The measurements of mobility underestimated the severity of periodontal disease; ninety five per cent of all teeth examined were considered to have a mobility score of 0 whereas 20 per cent were considered free of periodontal disease using PI. Radiographic examination did not add significantly to the PI and P.D.I. examinations.
Mycoplasma salivarium in human gingival sulci
Authors: David Engel L. , Kenny George E.
Published: July 2006

The prevalence and quantity of mycoplasmata in the gingival sulcus area of periodontally diseased and periodontally healthy subjects was tested. Mycoplasma salivarium was the predominant sulcular species and occurred in a significantly higher percentage of diseased subjects than healthy subjects (p<.0005) (86.7 % vs 31.8 %). When mycoplasmata were present in the sulcus their concentration was usually 106–107 per gram of fluid whereas the concentration in saliva was approximately 100 to 1000 fold less. Therefore M. salivarium appears to be primarily a sulcular organism. M. salivarium may be part of the complex plaque which appears to produce gingivitis.
Endosteal bone formation following vascular obstruction
Authors: Vandersall D.C. , Kennedy J.
Published: July 2006

Partial occlusion of the periodontal microvasculature was achieved by introducing black carbonized microspheres unilaterally into the external carotid artery of squirrel monkeys. The contralateral side of the animal served as its own control. One week following the vascular obstruction, tritiated 2‐glycine was injected intraperitoneally to label newly formed endosteal bone. All animals were sacrificed four weeks following the injection of tritiated glycine. The jaws were removed, hemi‐sected, fixed, decalcified, and sectioned bucco‐lingually through the interdental areas (cols). Autoradiography was performed on tissue sections selected from the posterior col areas of the experimental and control sides. Measurements were made from sections of interdental labelled and unlabelled endosteal bone surfaces. Less endosteal bone formation was evident on the experimental side following the vascular insult.
Dietary influences on the formation of dental calculus in rats
Authors: Shannon Ira L. , Carroll Edward C. , Madsen Kenneth O.
Published: July 2006

Eleven diets were evaluated for their ability to produce dental calculus in albino rats. A diet containing 50 % cornstarch, 32 % nonfat dry milk, 3 % liver powder, 5 % celluflour, 1 % cottonseed oil, 5 % powdered sucrose, 1 % calcium chloride dihydrate, 2.7 % sodium dihydrogen phosphate monohydrate, and 0.3 % magnesium sulfate (Francis and Briner 1969) was remarkably effective. On the basis of a 0–3 calculus scoring system, an average score of 2.36 (S.D. = 0.65) resulted after 4 weeks' exposure to the above diet and, after 8 weeks, the average score was 2.59 (S.D. = 0.56).

While it was found that, in general, high cornstarch and milk powder diets were associated with higher calculus scores, no other diet remotely approached the above diet in calculogenicity.
An electron microscopic study of the regeneration of gingival epithelium following gingivectomy in the dog
Authors: Innes P.B.
Published: July 2006

Regeneration of dog gingival epithelium following gingivectomy was studied electron microscopically. The wounds were sampled at 24 hour intervals until 14 days following the operation. From a relatively undifferentiated migrating epithelium the process of differentiation resulted in the following sequence of events. In areas where the cells made contact with the fibrin of the blood clot, a basal lamina and hemidesmosomes appeared, the number of cytofilaments increased as did the number of desmosomes and free ribosomes. Further differentiation in the masticatory epithelium was related to keratinization. The cytofilaments in the cells of the upper layers became grouped into bundles, membrane‐coating granules and keratohyalin granules appeared, the intercellular spaces in the superficial layers became narrowed and finally a stratum corneum was formed by the seventh day. In the epithelium lining the crevice a stratum corneum was not formed, the intercellular spaces in all the layers remained wide and the cells in the upper layers developed a relatively prominent Golgi apparatus and numerous membrane‐bound granules throughout their cytoplasm.

The result of the differentiation in the regenerated gingiva was the formation of masticatory and crevicular epithelium which were ultrastructurally similar to the two epithelia originally present.
The influence of time of examination, eating, smoking and frequency of brushing on the oral debris index
Authors: McKendrick A.J.W. , Barbenel L.M.H. , McHugh W.D.
Published: July 2006

The effect of time of day, eating since the teeth were last brushed, and the number of stained teeth in smokers, on the Oral Debris Index (Greene and Vermillion 1960) was examined. The effects were found to be non‐significant.

Increased frequency of toothbrushing was found to produce a statistically significant reduction in oral debris.
Dental anatomy and coronal cementum in the Mongolian gerbil
Authors: Wasserman B.H. , Moskow B.S. , Rennert M.C.
Published: July 2006

The embryogenesis and morphologic characteristics of the teeth and supporting structures of the Mongolian gerbil were studied in animals ranging in age from ten days to five years. Three molar teeth are present in each quadrant and consist of three, two, and one lobe respectively. The occlusal surfaces are flat and devoid of enamel. The lobular nature of the teeth effects a series of buccal and lingual grooves extending almost the entire height of the crown. On the buccal and lingual prominences of the crown lobes and on the interproximal surface, the enamel is covered by a thin layer of cementum which runs one‐sixth up the height of the tooth. Within the grooves, a thick covering of globular‐like cementum, which is continuous with the root covering, can be seen.
Periodontal conditions in patients treated with dental bridges
Authors: Silness John
Published: July 2006

The periodontal condition of 242 abutment teeth carrying full and partial crowns used for retaining dental bridges was compared with the periodontal condition of 242 contralateral teeth in the same patients. The periodontal condition was assessed by recording the Plaque Index (Silness and Löe 1964), Gingival Index (Löe and Silness 1963) and by measuring pocket depth according to Glavind and Löe (1967). The position of the retainer margins in relation to the gingival crest was recorded according to the Margin Index (Silness 1970). Abutments carrying complete crowns with full coverage showed larger amounts of soft deposits, more severe gingivitis and increased depth of the periodontal pockets compared to the contralateral teeth. This was the case whether or not patients had received instruction in methods to improve the oral hygiene. In instructed patients, the periodontal condition of abutments carrying complete crowns with limited coverage did not differ significantly from those of the control teeth. This was also the case for teeth carrying partial crowns with limited coverage in instructed patients.
Periodontal conditions in patients treated with dental bridges
Authors: Silness John
Published: July 2006

The periodontal condition of 385 lingual abutment tooth areas with varying location of the retainer margins was compared with that of 385 contralateral tooth surfaces which were caries‐free and devoid of fillings. The periodontal condition was assessed by recording the Plaque Index (Silness and Löe 1964), Gingival Index (Löe and Silness 1963) and by measuring pocket depth by the method of Glavind and Löe (1967). The location of the retainer margins was recorded according to the Margin Index (Silness 1970a). A supragingival position of the crown margins seemed to be the most favourable location, whereas retainer margins at and below the gingival crest interfered significantly with gingival health. The most harmful effects upon the gingival condition seemed to be produced by retainer margins located subgingivally.
A study of the effects of gingival plaque extracts on cells cultured in vitro
Authors: Baboolal R. , Mlinek A. , Powell R.N.
Published: July 2006

The effects of soluble and phenol extracted fractions of human dental plaque obtained from the gingival crevice on the growth and morphology of Baby Syrian Hamster cells (BHK21) were investigated. The results indicated that cells grown in the presence of both fractions showed considerable degenerative morphological changes involving lysis of the cytoplasm, deterioration of the nuclei and intra nuclear structures, when compared with control cultures. Both fractions produced marked inhibition on the growth cycle resulting in significant decrease in cell numbers. However, there were no significant differences between the soluble and phenol extracted fractions with regard to their ability to inhibit cell growth. Preliminary analyses of the fractions revealed that the soluble contained 15% protein and several reducing monosaccharides and two amino sugars. In the phenol extracted portions no proteins were detected. Electrophoretic studies indicated that both fractions were composed of more than one molecular species.
Disc electrophorethic pattern of gingival collagen isolated from a patient with palmoplantar hyperkeratosis
Authors: Shoshan Shmuel , Finkelstein Shifra , Rosenzweig Kurt A.
Published: July 2006

Acetic acid soluble collagen was extracted from a sample of clinically uninflamed gingiva obtained from a 14 year‐old boy suffering from Papillon‐Lefevre syndrome (PFS). After purification, the collagen was gelatinized and then examined by disc electrophoresis. Collagen extracted from samples of clinically healthy gingiva (NG) and clinically inflamed gingiva (IG) of otherwise healthy young people, was similarly treated. Comparison of the results showed that the disc electrophoretic pattern of PFS gingival collagen differed from that of NG and IG collagen, and that it was reminiscent of, but not identical with that of published electrophoretic patterns of collagens digested by animal collagenases.
Specific antibody in gingiva and submandibular nodes of monkeys with allergic periodontal disease
Authors: Ranney Richard R.
Published: July 2006

Gingiva and submandibular lymph nodes from 12 squirrel monkeys that had been sensitized to ovalbumin, and from 4 unsensitized monkeys, were studied for the presence of cells containing specific antibody after intracrevicular challenge with ovalbumin‐soaked thread. Immunofluorescent methods were used to identify antibody to ovalbumin in cells in these tissues.

The chronic allergic response in the gingiva of sensitized animals that had been challenged three times per week for three months did include cells containing antibody to the antigen used for sensitization and challenge. Such cells were not found in gingiva from similarly treated unsensitized monkeys, or from sensitized monkeys challenged for a shorter time.

A few antibody‐containing cells were found in the submandibular lymph nodes ipsilateral to chronic intracrevicular placement of antigen in unsensitized animals, indicating active sensitization by gingival absorption of antigen. Antibody formation by cells in submandibular nodes, induced by systemic sensitization, was continued in nodes ipsilateral to gingival challenge, but tended to disappear in contralateral nodes.
Attachment of plaque and calculus to tooth surfaces
Authors: Selvig Knut A.
Published: July 2006

The ultrastructural nature of the interface between dental hard tissue and soft and calcified deposits was studied in undecalcified and decalcified thin sections from 28 extracted human teeth. Uncalcified plaques contained clusters of densely packed microorganisms which adhered to cuticular structures or directly to the tooth surface. In calcified deposits, on the other hand, larger amounts of intercellular material generally separated the cells from each other and from the tooth surface. An intimate relationship existed in most instances between the intercellular matrix of calculus and the organic matrix of the dental hard tissue as well as between the mineral crystals of calculus and those of the underlying tooth surfaces.

Mechanical locking of the deposits in cracks, resorptions, carious lesions, and other defects of the tooth surface was frequently observed. Moreover, calculus was closely adapted to the sub‐microscopic irregularities which were present even on “smooth” tooth surfaces. At the ultra‐structural level, the predominant mode of attachment appeared to be the adhesion of organic interbacterial substance to the tooth surface, in addition to intercrystalline forces of inorganic nature acting between crystals of calculus and underlying tooth substance. The relative importance of the latter factor presumably increases as the concrement matures.
Ultrastructural features of chronic marginal gingivitis
Authors: Gavin John B.
Published: July 2006

Inflamed cat and dog gingivae were examined electron microscopically to determine the ultrastructural features of chronic marginal gingivitis and to compare inflamed with clinically healthy gingiva. With increasing degrees of inflammation there was an increase in: the dilatation of blood vessels; the number of intravascular, extravascular and intraepithelial neutrophils; the frequency and depth at which ruptured and degranulated neutrophils were observed; in the width of the intercellular spaces of the crevicular epithelium and in the number of plasma cells and macrophages. There was a corresponding decrease in the number of fibroblasts, collagen fibrils, and desmosomes in the crevicular epithelium. Some blood vessels were fenestrated and some showed concentric laminae of material which resembled and was continuous with the perivascular basal lamina. Breaks up to several microns in width were observed in the epithelial basal lamina and these were often associated with, or occupied by, neutrophils or macrophages. Neutrophils were found in the keratinized masticatory epithelium only in severely inflamed specimens. The striking features of chronically inflamed gingivae—wide intercellular spaces, neutrophil infiltration, cellular degeneration—were essentially those features which distinguish the crevicular region from other areas of the oral mucosa, but were quantitatively much increased.
Gingival collagen biosynthesis in mongolism
Authors: Claycomb C.K. , Summers G.W. , Hall W.B. , Hart R.W.
Published: July 2006

Collagen biosynthesis, as measured by conversion of 3–4 3H‐proline to 3H‐hydroxyproline, was studied in excised gingival samples utilizing an in vitro tissue slice incubation technique. Samples of clinically normal gingiva and gingiva affected by periodontitis were studied in ten mongoloid patients and eleven non‐mongoloid mentally normal patients. High 3H‐proline uptakes were found in all samples of mongoloid gingiva indicating a high level of collagen synthesis. A possible metabolic block in collagen maturation is suggested as an etiologic factor in the severe form of periodontitis observed.
Presence of leukocytes in crevices of healthy and chronically inflamed gingivae
Authors: Attström Rolf
Published: July 2006

The presence of leukocytes within the crevices of clinically healthy and chronically inflamed gingivae has been studied in human and dog. Cellular samples were obtained from the gingival crevices by the “Styroflex” technique. The area on the styroflex film showing the presence of leukocytes was determined and a differential count of the cells performed. Biopsies were also taken from dogs with clinically healthy gingivae.

Neutrophils, lymphocytes and monocytes were regularly found in samples from clinically healthy gingivae even when histological sections failed to show any inflammatory infiltrates in the gingival connective tissue. The differential counts showed 95–97 % neutrophils, 1–2 % lymphocytes and 2–3 % monocytes. Increased numbers of leukocytes were found in the crevices of chronically inflamed gingivae. However, the proportions of the various leukocytes were the same as those found in the crevices of clinically healthy gingivae. The results of the present investigation support the view that only quantitative differences exist between clinically healthy and chronically inflamed gingivae.
Emigration of blood neutrophils and monocytes into the gingival crevices
Authors: Attström Rolf , Egelberg Jan
Published: July 2006

The migration of neutrophil polymorphonuclear leukocytes and monocytes into crevices of resting clinically healthy, and chronically inflamed gingivae has been studied in dogs. Cellular samples were obtained from crevices by the use of the “Styroflex” technique. Labelling of blood neutrophils and monocytes was performed with intravenously injected colloidal carbon. Samples were collected from the crevices at various time intervals after the labelling procedure. Labelled neutrophils and monocytes were found in the crevices of both healthy and chronically inflamed gingivae. The cells appeared to migrate at a higher rate into the inflamed crevices than into the healthy crevices. The monocytes seemed to migrate somewhat more slowly than the neutrophils.
The effect of dietary carbohydrates on the deposition of calculus in baboons
Authors: Ashley F.P. , Naylor M.N.
Published: July 2006

The lower incisor teeth of 28 male baboons used in a six‐month nutritional study were examined post mortem and assessed for calculus deposits. Animals fed a predominantly sucrose diet were found to have significantly more calculus than animals on predominantly fructose and spray dried liquid glucose diets.
Periodontal conditions in patients treated with dental bridges
Authors: Silness John
Published: July 2006

The investigation was undertaken to evaluate the effect on the periodontal conditions of fixed unilateral bridges which had been in the mouth 1 to 3 years. Seventy‐three bridges in 73 patients (50 women, 23 men) were examined. One group of 35 individuals had been instructed in methods for improving their oral hygiene, whereas another group (38 individuals) had not.

In all, 146 abutment teeth were examined. An equal number of homologus teeth in the same patients served as controls. The gingival state and oral hygiene were recorded according to index systems proposed by Löe and Silness (1963) and Silness and Löe (1964). Pocket depth measurements were made as explained by Glavind and Löe (1967). The location of the crown margins of the bridge retainers was recorded according to a Margin Index System proposed by the author. The distribution of soft deposits and the location of gingivitis were similar around the abutment teeth and the homologous teeth. The average pocket depth of the abutment teeth was not deeper than that of the controls. In areas with crown margins below the gingival crest, more severe gingivitis was registered than in the control areas. The periodontal conditions were better in the individuals who had been instructed to practice oral hygiene measures as compared to the non‐instructed individuals. Possible reasons why soft deposits remain undetected on clinical examination of subgingival restorations are discussed. It is suggested that the gingival inflammation around the abutment teeth and the homologous teeth is caused by the usual bacterial mechanisms.
In vitro experiments on gingival exudate mesurements
Authors: Leirskar Jakob
Published: July 2006

Different test solutions moved 2.5–2.9 times faster on Munktell's filter paper no. 3 than on Whatman filter paper no. 1. The paper quality may thas be an important factor when measuring gingival exudatc by the filter paper method, and results obtained with different types of paper may not be comparable.

Upon descending chromatography a 30–50 per cent increase was found in mobility as compared to ascending chromatograpiiy, indicating that gingival exudate measurements may be influenced by the flow direction.
Scanning electron microscopy of the dog periodontium
Authors: Shackleford John M.
Published: July 2006

The periodc‐ntium of premolar teeth of dogs has been examined by scanning electron microscopy. lighl microscopy and microradiography. Scanning electron microscopy reveals a highly developed plexus of indifferent fibers associated with the principal fibers, The indifferent fiber plexus may be important in accomodalion of the periodontal ligament to tooth movement through anastomotie relationships between the plexus and principal fibers. Principal fibers perforate alveolar bone as compact bundles of smaller fibers. Perforating fibers of cementum enter calcified matrix as coiled or straight fibers. The number of coiled fibers is greatest in acellular cementum and the straight fibers are largest in diameter at root apices.