bluuebunny/crossref_metadata_2025 huggingface dataset:
The geomorphological setting of some of Scotland's east coast freshwater mills: a comment on Downward and Skinner (2005) ‘Working rivers: the geomorphological legacy . . .’
Authors: Bishop Paul , Jansen John D
Published: December 2005

Many of the water mills on Scotland's east coast streams, unlike those discussed recently by

Downward and Skinner (2005

Area 37 138–47), are found in predominantly bedrock reaches immediately downstream of knickpoints (i.e. bedrock steps). Bedrock knickpoints in the lower reaches of Scottish rivers are a widespread fluvial response to the glacio‐isostatic rebound of northern Britain. These steps in the river profile propagate headward over time, but for intervals of a few centuries or so they are sufficiently stable to be exploited for the elevational fall necessary to power the mill wheel. Many of these mills were apparently powered by ‘run‐of‐the‐river’, as are some today that formerly had mill dams. The typical lack of sediment storage along the erosional lower reaches of many Scottish rivers means that failure of mill structures in Scotland will probably have less dramatic geomorphological and management implications than those suggested by Downward and Skinner for southern English rivers.
Out there and in here: studying Eastern Europe in the West
Authors: Stenning Alison
Published: December 2005

This paper seeks to explore the challenge of studying geographies of Eastern Europe in Western Europe. It reflects on the growing relationships – imagined and material – between Eastern and Western Europe and engages in contemporary debates over ‘relational geographies’ to make a case for geographies which imagine our plural, European spatial connections, which connect different parts of the continent and which encourage the re‐examination and renegotiation of ideas across East and West in the post‐Cold War world. In these ways, the paper borrows from postcolonial frameworks and the ongoing reassessment of area studies to call for studies of Eastern and Western Europe which reinvigorate our "sense of Europe".
The relationship between herders and trees in space and time in northern Cameroon
Authors: GAUTIER DENIS , BONNERAT AMÉLIE , NJOYA ABOUBAKAR
Published: December 2005

Extensive herding is an important activity in northern Cameroon, in terms of both the local social economy and local land management. However, this activity is strongly linked to the availability and accessibility of fodder resources. Due to territorial processes, such as land clearance and wood harvesting, this resource is receding and pasturelands are becoming fragmented. Herders are facing new challenges to secure their livelihoods, and, in this context, fodder trees are emerging as a key resource, allowing herds to subsist up to the end of the dry season. Increasingly, trees are playing a significant part in the herders’ strategies to feed their herds in time and space and to ‘root’ their activities to particular lands. This trend requires an analysis of the importance of fodder trees in the definition of territorial strategies operated by herders in northern Cameroon, in the context of various herding systems (nomadic herding, agro herding using transhumance, and settled agro herding). A discussion of herding strategies needed to address the decreasing access to fodder resources highlights the problems of current extensive herding systems and leads to proposed alternatives.
The dynamics of vulnerability: locating coping strategies in Kenya and Tanzania
Authors: ERIKSEN SIRI H , BROWN KATRINA , KELLY P MICK
Published: December 2005

We investigate how smallholder farmers at two sites in Kenya and Tanzania cope with climate stress and how constraints and opportunities shape variations in coping strategies between households and over time during a drought. On the basis of this analysis, we draw out implications for adaptation and adaptive policy. We find that households where an individual was able to specialize in one favoured activity, such as employment or charcoal burning, in the context of overall diversification by the household, were often less vulnerable than households where each individual is engaged in many activities at low intensity. Many households had limited access to the favoured coping options due to a lack of skill, labour and/or capital. This lack of access was compounded by social relations that led to exclusion of certain groups, especially women, from carrying out favoured activities with sufficient intensity. These households instead carried out a multitude of less favoured and frequently complementary activities, such as collecting indigenous fruit. While characterized by suitability to seasonal environmental variations and low demands on time and cash investments, these strategies often yielded marginal returns. Both the marginalization of local niche products and the commercialization of forest resources exemplify processes leading to differential vulnerability. We suggest that vulnerability can usefully be viewed in terms of the interaction of such processes, following the concept of locality. We argue that coping is a distinct component of vulnerability and that understanding the dynamism of coping and vulnerability is critical to developing adaptation measures that support people as active agents.
Geographies of relatedness
Authors: Nash Catherine
Published: December 2005

This paper explores the analytic purchase and substantive concerns of what I am callinggeographies of relatedness. Drawing on recent work in feminist anthropology which has reconsidered kinship as classificatory system and practice, and highlighting the attentiveness to sites, scales and contexts within this work, I suggest ways in which a focus on relatedness may shape approaches to established and emerging matters of concern in human geography. I consider first the foundational status but flexible meaning of ‘blood’ in kinship thinking, and the ways the flexibility of kinship can be curtailed and its foundational status reinstated in relation to the nation and the state. Second, I consider the geographies of relatedness that are constituted through and practised in the process of establishing degrees of biological connection, delimiting difference, mapping human ‘diversity’ and defining personal, collective and human origins at different scales and with different effects. A focus on geographies of relatedness, I argue, highlights the ways blood ties or similarly naturalized connections move between and connect categories of relatedness with different sizes, extents and configurations across space, as well as different temporalities. It suggests an alertness to new global mappings of human relatedness and difference and combines a critical attention to ideas of the ‘nature’ of human reproduction as foundational, original or primal in the natural order of the social, to ideas of ‘place of origin’: personal, national, ethnic, racialized, universal in their familiar and emergent forms.
Science, text and space: thoughts on the geography of reading
Authors: Livingstone David N
Published: December 2005

The idea of a ‘geography of reading’ provides a potential point of conversation between the cultural and scientific wings of our profession. Here I explore some dimensions of the geography of reading scientific texts. Drawing on a number of theoretical pronouncements – Gadamer's ‘fusion of horizons’, Said's ‘travelling theory’, Secord's ‘geographies of reading’, Beer's ‘miscegenation of texts’, Fish's ‘interpretive communities’ and Rupke's ‘geographies of reception’– I focus on the spaces where scientific theories are encountered. The argument is that where scientific texts are read has an important bearing on how they are read. This realization points to a fundamental instability in scientific meaning and to the crucial significance of what might be called located hermeneutics. As a case study in the development of a cartographics of scientific meaning, I explore the different ways in which Darwin's fundamentally biogeographical theory of evolution by natural selection was construed in a number of different settings. The sites I have chosen to illustrate this are the scientific communities which congregated around the Charleston Museum of Natural History in South Carolina, the Wellington Philosophical Society and New Zealand Institute, and the St Petersburg Society of Naturalists in Russia during the second half of the nineteenth century. In each case the encounter with evolution theory, and the ways it was interpreted, are shown to have been shaped by local cultural politics, thereby disclosing the critical role that space plays in the production of scientific meaning.
Human geography without scale
Authors: Marston Sallie A , Jones John Paul , Woodward Keith
Published: December 2005

The concept of scale in human geography has been profoundly transformed over the past 20 years. And yet, despite the insights that both empirical and theoretical research on scale have generated, there is today no consensus on what is meant by the term or how it should be operationalized. In this paper we critique the dominant – hierarchical – conception of scale, arguing it presents a number of problems that cannot be overcome simply by adding on to or integrating with network theorizing. We thereby propose to eliminate scale as a concept in human geography. In its place we offer a different ontology, one that so flattens scale as to render the concept unnecessary. We conclude by addressing some of the political implications of a human geography without scale.
A tale of two scales, or the two geomorphologies
Authors: Summerfield Michael A
Published: December 2005

Since the 1960s the analysis of small‐scale surface processes has been the dominant approach in geomorphology, the previous focus on regional‐scale landscape evolution having been largely abandoned as a result of the lack of knowledge of processes and process rates at the relevant temporal and spatial scales. It has recently been acknowledged that small‐scale, surface process geomorphology alone is unable to provide an understanding of long‐term landscape development, both because of the significance of tectonics, and because of the important role of contingency at the large temporal and spatial scales involved. But the major advances in geochronological techniques and numerical modelling of landscape evolution that are now revolutionizing our understanding of long‐standing questions of landscape evolution have been largely developed and applied by researchers from outside the traditional geomorphology community. As a result, two distinct communities of researchers have emerged concerned with different scales of landform analysis, but the progress of geomorphology will be best served by greater interaction between them.
Making connections and thinking through emotions: between geography and psychotherapy
Authors: Bondi Liz
Published: December 2005

The current upsurge of interest in emotions within geography has the potential to contribute to critical perspectives that question conventional limits to scholarship. Three precursors of emotional geographies are discussed in this context (humanistic, feminist and non‐representational geographies). Connections between emotional geographies and psychotherapy are explored with a view to resisting the equation of emotion with individualized subjective experience, and developing situated, relational perspectives. Psychotherapy is approached as a theory of practice that accords central importance to affective qualities of relationships, which is shown to be directly relevant to geographical engagements with emotion. The distinction between feelings and representations of feelings is revisited through a discussion of psychotherapeutic meaning‐making.
Weight of Evidence: A Review of Concept and Methods
Authors: Weed Douglas L.
Published: December 2005

“Weight of evidence” (WOE) is a common term in the published scientific and policy‐making literature, most often seen in the context of risk assessment (RA). Its definition, however, is unclear. A systematic review of the scientific literature was undertaken to characterize the concept. For the years 1994 through 2004, PubMed was searched for publications in which “weight of evidence” appeared in the abstract and/or title. Of the 276 papers that met these criteria, 92 were selected for review: 71 papers published in 2003 and 2004 (WOE appeared in abstract/title) and 21 from 1994 through 2002 (WOE appeared in title). WOE has three characteristic uses in this literature: (1) metaphorical, where WOE refers to a collection of studies or to an unspecified methodological approach; (2) methodological, where WOE points to established interpretative methodologies (e.g., systematic narrative review, meta‐analysis, causal criteria, and/or quality criteria for toxicological studies) or where WOE means that “all” rather than some subset of the evidence is examined, or rarely, where WOE points to methods using quantitative weights for evidence; and (3) theoretical, where WOE serves as a label for a conceptual framework. Several problems are identified: the frequent lack of definition of the term “weight of evidence,” multiple uses of the term and a lack of consensus about its meaning, and the many different kinds of weights, both qualitative and quantitative, which can be used in RA. A practical recommendation emerges: the WOE concept and its associated methods should be fully described when used. A research agenda should examine the advantages of quantitative versus qualitative weighting schemes, how best to improve existing methods, and how best to combine those methods (e.g., epidemiology's causal criteria with toxicology's quality criteria).
Some Limitations of a Proposed Linear Model for Antimicrobial Risk Management
Authors: Cox Louis Anthony (Tony)
Published: December 2005

The FDA Center for Veterinary Medicine (CVM) (Bartholomew et al., 2005) recently proposed an approach to risk management based on the linear modeling framework: Risk = K × Exposure. They suggest that, once K has been estimated from historical data, it can be used to predict how limiting future exposure will reduce future risk. They illustrate the approach for fluoroquinolone‐resistant campylobacter in chicken. However, despite its appealing simplicity, the proposed approach confuses a possibly meaningless descriptive statistical ratio with a valid predictive causal relation. In general, the historical ratio K = (Risk/Exposure) may not predict how changing future exposures will affect future risks, and hence it does not necessarily provide an appropriate guide to current risk management actions. We identify several limitations of the proposed framework, including omission of frequency and severity of human health harm in quantifying “Risk” and omission of microbial load from “Exposure.” Finally, we show that an extended linear modeling approach that considers impacts of changing animal antibiotic use on susceptible as well as on resistant bacteria is consistent with the conclusion that reducing “Exposure” can greatly increase “Risk.”
A model for decision making regarding periodontal treatment needs
Authors: Wennström Jan L. , Papapanou Panos N. , Gröndahl Kerstin
Published: December 2005

Abstract The aim of this study was to present a tentative model for decision making regarding periodontal treatment needs, based on the amount of remaining periodontal bone support. In the model presented, a maintained alveolar bone height of one third of the root length at the age of 75 years was regarded to be a reasonable goal. The data analyzed were derived from a patient sample of 194 dentate individuals aged 25–70 years from whom 2 full mouth series of intraoral radiographs, approximately 10 years apart, were available. For teeth present at both examinations, the radiographs were evaluated with respect to alveolar bone levels at the mesial and distal aspect of the teeth, i.e., the distance between the cemento‐enamel junction and the most coronal level of the bone support. Longitudinal alveolar bone level change was determined for each tooth site and the alteration in alveolar bone height per 5‐year interval between 25 and 75 years of age was described. Based on the calculated mean bone loss data, a rate factor was determined for each tooth site and used in the final description of the alveolar bone level for each particular tooth site at ages 30, 35, 40, …, and 70 years, depicting the amount of bone loss beyond which therapeutic intervention has to be made in order to meet the defined goal of the tentative model. The relevance of the model and its applicability are discussed.
Comparative antiplaque activity of sanguinarine and chlorhexidine in man
Authors: Quirynen M. , Marechal M. , van Steenberghe D.
Published: December 2005

Abstract This clinical investigation examined the effect of a sanguinarine extract on bacterial plaque growth in man. Three different mouthrinses were examined: (i) Veadent® containing 0.03% sanguinarine and 0.2% zinc chloride (test rinse); (ii) a vehicle solution containing all the excipients of Veadent® except the 0.03% sanguinarine (control rinse); (iii) Hibident® a 0.2% chlorhexidine digluconate formulation (positive control rinse). The trial in which 12 dental students participated, was designed as a single‐blind, cross‐over study. During 3 experimental periods of 18 days, the participants refrained from mechanical oral hygiene and rinsed twice a day with one of the above mentioned solutions. Between experimental phases, a wash‐out period of 11 days was instituted. In each subject, 4 teeth were randomly selected for assessment. Clinical evaluations were performed at days 1 (0, 4, 8, 12 hours), 2, 4, 11 and 18. The plaque on the buccal surfaces of the selected teeth was disclosed with neutral red 0.5% and colour slides taken. The % of the tooth surface covered with plaque was calculated planimetrically from these colour slides. The present results show an excellent anti‐plaque effect with Hibident®, a very small effect with Veadent® and a negligible effect with the vehicle solution without the sanguinarine. These findings would suggest that the Veadent® mouthrinse would have at most only a limited role as a plaque inhibitor.
Evaluation of clinical and radiographic scoring methods before and after initial periodontal therapy
Authors: Hämmerle Christoph H. F. , Ingold Hans‐Peter , Lang Niklaus P.
Published: December 2005

Abstract The purpose of the present study was to compare the determination of the attachment level by probing and by measuring bone heights prior to and after the completion of a hygienic phase of periodontal therapy. 68 patients with moderate to severely advanced periodontitis underwent initial (hygienic phase) therapy including scaling and root planing, oral hygiene instructions and the elimination of plaque retention factors. Measurements of pocket probing depths, probing attachment levels and the location of gingival margins in relation to the cemento‐enamel junction were performed at 4 aspects of each tooth with a thin calibrated probe at a baseline examination and 3 to 5 months following treatment. During these 3 to 5 months, the patients were kept in a maintenance care program. On the full‐mouth radiographs obtained at baseline, the distance from the cemento‐enamel junction to the marginal alveolar crest was measured in millimeters and as a % of the root length. Furthermore, a subgroup of 11 patients, who were scheduled for modified Widman flap procedures, received another full‐mouth radiographic examination before the surgical treatment. In addition, the level of the alveolar crest was assessed with a periodontal probe during the surgical procedure. The comparison of the different clinical and radiographic parameters showed the best correlations between the various radiographic measurements of bone heights (r = 0.87; r = 0.86). Clinical measurements of probing attachment level and probing level of the alveolar crest revealed slightly weaker correlations (r = 0.72). When comparing radiographic bone heights with clinical measurements of probing attachment levels, the lowest correlations were found (r = 0.65; r = 0.61; r = 0.61).
The composition of gingival inflammatory cell infiltrates in children studied by enzyme histochemistry
Authors: Alcoforado Gil Alves Pessanha , Kristoffersen Tore , Johannessen Anne Christine , Nilsen Rune
Published: December 2005

Abstract Gingival biopsies were obtained from 23 children, aged 5‐11 years (8.6 ± 1.8 years). Specimens were taken from areas of the gingiva adjacent to the teeth which were to be extracted because of caries or its sequelae and which clinically had a gingival index score of at least 1. Staining for α‐naphthyl acetate esterase with unspecific esterase at pH 5.8 (ANAE) permitted identification of T lymphocytes, monocytes/macrophages, plasma cells and non‐reactive (ANAE‐negative) cells. Cells which tentatively were identified as “natural killer” (NK) cells were also observed. Differential cell counting was performed for 10 specimens, selected on the basis of the presence of a well‐defined inflammatory infiltrate, clear morphology throughout and good ANAE staining. Cell counts confirmed earlier studies showing that lymphocytes predominate in the inflammatory infiltrates in childrens' gingivitis. T lymphocytes dominated particularly in the periphery of the most densely infiltrated areas. Relatively few plasma cells were seen. It was concluded that T lymphocytes dominate in the inflammatory infiltrate in childrens' gingivitis.
Darkground microscopy of subgingival plaque from the top to the bottom of the periodontal pocket
Authors: Omar A. A. , Newman H. N. , Bulman J. , Osborn J.
Published: December 2005

Abstract Part of the results of a study of subgingival plaque by darkground microscopy was used to investigate morphotype distribution at different levels within the periodontal pocket. Subgingival plaque was sampled at coronal, middle and apical levels from each of 28 approximal surfaces on 28 teeth extracted from 28 adults with untreated moderate to advanced penodontitis. Sample preparation and darkground microscopy were as described previously. The data recorded only the subgingival level at which the maximum count occurred for a given morphotype and subject. It was found that the maximum count of spirochaetes occurred most frequently at the apical level (p<0.05) and the maximum count of‘others' at the coronal level (p<0.05). Also, coccal counts showed a trend to increase the more apical the sample. Standardised darkground microscopy was able to show that the sampled subgingival level had a significant influence on plaque bacterial morphotype distribution, indicating the importance of accurate sampling of subgingival plaque at the most apical level.
Ultrastructural evidence of large granular lymphocyte (LGL) activity in lesions of chronic adult periodontitis
Authors: Cobb Charles M. , Singla Om , Theisen Frank C. , Shultz Rudane E.
Published: December 2005

Abstract The purpose of this investigation was to determine, on the basis of Ultrastructural evidence, whether large granular lymphocyte (LGL)‐mediated cytotoxic activity could be identified in lesions of chronic adult periodontitis. 18 gingival papilla biopsies were obtained from 8 adult patients, each satisfying the clinical criteria for chronic adult periodontitis. One‐half of each biopsy was processed for examination by transmission electron microscopy (TEM). B‐lymphocyte, T‐lymphocyte, and NK‐cell contributions to the inflammatory cell infiltrate were determined by subjecting the remaining one‐half to the 3‐layer avidin‐biotin affinity immunoperoxidase technique. Immunohistochemistry using the anti‐human leu‐11b monoclonal antibody (representative of NK‐cells which are known to comprise approximately 80% of the LGL population) showed that the Leu‐11b + population comprised 3–7% of the total monocytic infiltrate. The Leu‐11b + cells tended to occur as single cells or in small clusters of 3‐12 cells. Generally, the Leu‐11b+ cells exhibited perivascular locations situated subjacent to the epithelial basal lamina. TEM observations showed LGLs in intimate contact with fibroblasts that exhibited morphologic changes consistent with cellular damage or degeneration. In addition, LGLs were observed to exhibit apparent non‐cytotoxic contacts with plasma cells, macrophages and other monocytic cells.
Occurrence of Bacteroides gingivalis, Bacteroides intermedius and Actinobacillus actinomycetemcomitans in severe periodontitis in relation to age and treatment history
Authors: Rodenburg J. P. , van Winkelhoff A. J. , Winkel E. G. , Goené R. J. , Abbas F. , de Graaff J.
Published: December 2005

Abstract A total of 242 subjects including 138 untreated severe periodontitis patients and 104 patients with refractory periodontal disease, previously treated for severe periodontitis, were examined for the occurrence of Actinobacillus actinomycetemcomitans, Bacteroides gingivalis and Bacteroides intermedius. Pooled subgingival samples of representative periodontal lesions were used for anaerobic cultivation on blood agar and for the enumeration of A. actinomycetemcomitans on selective TSBV medium, 97% of the untreated patients were infected with one or more of the test micro‐organisms. In this patient group, the occurrence of A. actinomycetemcomitans, B. gingivalis and B. intermedius was 54%, 48% and 63%, respectively. The prevalence of A. actinomycetemcomitans positive patients appeared to be age related and decreased with increasing age. Likewise, the number of patients solely infected with A. actinomycetemcomitans decreased with increasing age. The prevalence of B. gingivalis infected patients appeared to increase with increasing age. These phenomena were not observed in the refractory periodontitis patients. The occurrence of A. actinomycetemcomitans, B. gingivalis and B. intermedius in the refractory periodontitis group was 55%, 27% and 59%, respectively. A statistical significant difference in the prevalence of B. gingivalis was found between the untreated and the refractory periodontitis patients. In both patient groups, the relative proportion of A. actinomycetemcomitans was significantly higher in subjects with this bacterium as the sole indicator microorganism than in patients who, besides being infected with A. actinomycetemcomitans, were also infected with black‐pigmented Bacteroides species. Furthermore, in comparison with untreated patients, unsuccessfully treated patients solely infected with A. actinomycetemcomitans had on average a lower number but also a higher mean % of this bacterium. This indicates that A. actinomycetemcomitans comprised a larger part of the total subgingival microflora in these patients. It was concluded that the occurrence of A. actinomycetemcomitans, B. gingivalis and B. intermedius in untreated periodontitis is related to age. Furthermore. A. actinomycetemcomitans and B. intermedius have a higher incidence in refractory periodontitis patients in comparison with B. gingivalis.
Suspected periodontopathogens in erupting third molar sites of periodontally healthy individuals
Authors: Mombelli A. , Buser D. , Lang N. P. , Berthold H.
Published: December 2005

Abstract 29 periodontally healthy subjects (11 female and 18 male) with a mean age of 24 years (range 19 to 38 years) and with partially erupted lower third molars participated in this study. 18 subjects demonstrated no signs or symptoms of acute inflammation and were without pain (group A). 5 subjects showed redness of the pericoronal tissues and experienced pain upon palpation (group B). 6 subjects suffered from acute pain and exhibited formation of pus (group C). Microbiological samples were taken from the lateral aspect of the pericoronal space using the paperpoint‐method. Continuous anaerobic techniques were utilized for microbiological processing. The samples were cultivated on ETSA and on selective media and were studied by darkfield microscopy. Gram‐negative anaerobic rods accounted for 27% (group A), 34% (group B) and 39% (group C) of all organisms growing on ETSA. Bacteraides intermedius was detected in 61% (group A), 80% (group B) and 83% (group C) of the samples. B. gingivalis was found in 1 sample of group A only. Fusobacterium sp. was detected in 56% (group A), 80% (group B) and 33% (group C) of the samples. Capnocytophaga were seen in 67% (group A), 20% (group B) and 50% of the samples. Actinobacillus actinomycetemcomitans was found in 44% (group A), 40% (group B) and 17% (group C). 72% of the group A and 100% of the group B and C samples contained spirochetes. In all of those positive samples, small spirochetes were present, but only 78% contained medium and only 48% large spirochetes. These results demonstrate that organisms which are thought to be important in the etiology of periodontitis are present in young adults without periodontal disease if suitable ecological conditions such as pocket‐like structures of partially erupted teeth are provided.
The effect of triclosan, stannous fluoride and chlorhexidine products on: (II) Salivary bacterial counts
Authors: Jenkins S. , Addy M. , Newcombe R.
Published: December 2005

Abstract A previous study demonstrated that triclosan and stannous fluoride containing oral hygiene products reduced plaque regrowth compared to saline but were not more effective than a conventional commercial fluoride/anionic detergent toothpaste. To further understand these results, this study measured the persistance of antimicrobial activity of the same products by recording the duration of salivary bacterial count reductions following a single exposure to each product. Comparison was also made with a chlorhexidine rinse as the positive control. From a panel of 16 volunteers, in an 8‐cell randomised cross‐over designed study, salivary bacterial counts were recorded at baseline and to 420 min. All test and control products were significantly more effective than saline and significantly less effective than chlorhexidine at suppressing bacterial counts. Unlike chlorhexidine, evidence of bacterial recovery was apparent after the 30‐min sampling time. There were essentially no significant differences between the test and control products, although the stannous fluoride toothpaste performed marginally better than other products. The findings are consistent with the plaque regrowth results previously obtained and again demonstrate to date that it is difficult to surpass the antimicrobial and plaque inhibitory properties of conventional commercially available toothpastes by the addition of antimicrobial agents such as triclosan and metal salts.
Optimal dosage of chlorhexidine acetate in chewing gum
Authors: Ainamo Jukka , Nieminen Anja , Westerlund Ulla
Published: December 2005

Abstract In a previous study, 800 mg pieces of sorbitol‐flavored gum, each piece containing 5 mg chlorhexidine (CHX) acetate, when chewed 2 at the time 5 × daily, were found to have an excellent plaque growth inhibiting effect. The aim of Trial 1 of the present study was to assess whether chewing only 2 × daily, 2 pieces of the same concentration CHX gum for about 10 min would be as effective. 6 dental students participated in the 3 × randomly crossed over double‐blind clinical trial. During the 5‐day chewing periods, no other oral hygiene measures were allowed. The Hibitane Dental (HD) rinse was used as a positive and the gum base containing neither CHX nor the sweetening agent as a negative control. At the end of each test period, recordings were made for the plaque index (P11), the plaque wet weight (PWW) and the relative area of plaque covered tooth surface (plaque area %). Chewing of CHX gum twice daily inhibited plaque growth as effectively as the HD rinse. The aim of Trial 2 was to assess the antiplaque effect of lower concentration CHX gums with, hopefully, a less unpleasant taste. For this trial, 8 dental students were recruited to chew 2 × daily during 6‐day periods two 800 mg pieces of sorbitol‐flavored gum, each piece now containing either 5 mg, 4 mg or 3 mg CHX acetate. The effect of these dosages did not differ from the effect of the HD rinse. Chewing 2 × daily for 6 days only one 800 mg piece of gum containing 5 mg CHX acetate resulted in higher PIT and plaque area % scores than use of HD rinses 2 x daily. The subjective evaluation by the test subjects revealed an inverse correlation between effect and taste of the CHX products.
Mycoplasma in relation to gingivitis and periodontitis
Authors: Kwek H. S. N. , Wilson M. , Newman H. N.
Published: December 2005

Abstract In this study, mycoplasma were enumerated in the gingival crevicular fluid (GCF) of gingivitis and periodontitis patients. GCF samples were obtained from the mesial (approximal) gingival crevice or periodontal pocket of the maxillary right first permanent molar. Samples were cultured anaerobically on a medium selective for mycoplasmas as well as on a non‐selective medium to obtain a total anaerobic count. Mycoplasmas were present in the GCF of both gingivitis and periodontitis patients, but a greater % was obtained from the GCF of patients with periodontitis. The proportions of mycoplasma appeared to be independent of the disease activity as expressed by bleeding on probing (FBI), but to be related to probeable pocket depth, as shown by the higher %s in periodontitis than gingivitis for a given FBI. On the basis of an increased proportion in relation to disease severity, mycoplasmas would therefore appear to be amongst those micro‐organisms associated with CIPD.
The effectiveness of a patient‐applied tooth desensitizing gel A pilot study
Authors: Reinhart Thomas C. , Killoy William J. , Love John , Overman Pamela R. , Sakumura Joseph S.
Published: December 2005

Abstract Potassium nitrate has been found to be an effective ingredient for reducing dentinal hypersensitivity. The purpose of this study was to evaluate the effectiveness of a patient‐applied 10% potassium nitrate glycerine‐based gel in decreasing dentinal sensitivity on cold on teeth with exposed dentin apical to the cementoenamel junction. 12 patients, each having 3 hypersensitive teeth, were tested. The patients were divided into 3 treatment groups: group 1 was treated with a glycerine‐based ‐10% potassium nitrate gel: group 2 was treated with a glycerine gel without potassium nitrate; and group 3 received no gel and no treatment (control). Following brushing and flossing, groups 1 and 2 applied the gel to the test teeth using custom‐made soft acrylic trays, for a period of 5 min/ day for 4 weeks. Patient responses to cold water stimuli of 20° C, 10° C and 0° C, were measured at baseline (week 0). then at 1‐, 2‐, 3‐ and 4‐week intervals. Group 1 patients showed a significant decrease in sensitivity to cold at week 2 only. The group 2 patients showed a significant decrease in sensitivity to cold after 3 and 4 weeks. A statistically significant decrease in sensitivity was noted between group 2 and group 3 patients at week 3. The most sustained decrease in sensitivity to cold was found on teeth treated with plain glycerine.
The prevalence of overhanging margins in posterior amalgam restorations and periodontal consequences
Authors: Pack Angela R. C. , Coxhead Leslie J. , McDonald Barry W.
Published: December 2005

Abstract The purpose of this study was to determine the prevalence of overhanging margins and associated periodontal status in 100 patients who had received completed treatment by final year dental students. Pockets, bleeding on probing and clinically detectable overhanging margins were recorded on all posterior teeth. Overhanging margins on approximal restorations were detected by use of bitewing radiographs. 1319 teeth were examined in which 2117 restored surfaces were evaluated. Of these, 1186 (56%) had overhanging margins. 62% of all approximal restorations had overhanging margins while 35% of buccal and 40% of lingual restorations had overhanging margins. 59% of new approximal restorations placed in previously unrestored surfaces had overhanging margins, and 595 overhanging margins identified on pre‐treatment radiographs were still present on post‐treatment radiographs. 64.3% of pockets adjacent to overhanging margins were >3 mm, compared with 23.1% of pockets adjacent to unrestored surfaces and 49.2% of pockets adjacent to restorations without overhanging margins. A similar association existed between restorative status and bleeding. 32% of pockets adjacent to overhanging margins bled on probing compared with 10.5% of pockets adjacent to unrestored surfaces and 21.6% of pockets adjacent to restorations without overhanging margins. Periodontal disease was more severe when overhangs were present. However, when approximal overhanging margins were adjacent to an edentulous space, the periodontal effects were lessened. When adjacent to neighbouring teeth, overhanging margins also significantly affected the periodontal status of those teeth.
Cellular reactions in pulpal and periodontal tissues after periodontal wound debridement
Authors: Bergz J‐O. , Blomlöf L. , Lindskog S.
Published: December 2005

Abstract Periodontal wounds in monkeys were prepared with a bur followed by the application of microbially contaminated cotton pellets. 3 weeks later, the wounds were debrided by scaling followed by etching with citric acid or by treatment with carbonate/peroxidate. The cellular reactions in the periodontal tissues and in the pulp 4, 11, 25, 39 and 53 days after treatment were followed with light microscopy. The marginal periodontium showed heavy inflammatory reactions immediately after treatment, regardless of the debridement procedure. 25 days after debridement, a long epithelial junction had been formed. The apical part of the epithelium deviated from the root surface into the connective tissue, delineating a heavily inflamed part of the connective tissue. After 39 to 53 days, most of the experimental wounds were covered by an epithelial lining. The pulpal reactions were generally limited to a production of irregular dentin on the pulpal wall facing the periodontal wound. It was concluded that the marginal healing pattern following various chemical treatments to the root surface followed, in all essential aspects, conventional treatment with scaling and root planing.
One‐wall proximal defects: pre‐treatment characteristics and bone response following flap curettage
Authors: Heins P. , Avriett A. , Chace R. , Hartigan M.
Published: December 2005

Abstract Several characteristics of 53 infrabony defects were compared with changes in bone height, following treatment by flap‐curettage and regular maintenance. The mean post‐surgical interval was 11.4 years. Proximal angular defects from mandibular posterior teeth comprised the study population. Changes in bone height following therapy were compared with the pre‐treatment bone loss, tooth‐bone angle, and inter‐radicular width. The influence of the post‐surgical duration on these factors was also evaluated. Bone height was examined at both the deep and shallow sides of each proximal defect. Data were collected from enlarged tracings of pre‐and post‐treatment radiographs. Gain or loss of bone was established at >2 SD of the measurement error as determined by replicate calibration trials. Deep‐side sites which gained bone exhibited the most pretreatment bone loss at a mean of 57.1%. These sites also exhibited a mean tooth‐bone angle of 31.9° and a mean inter‐radicular width of 3.1 mm. Gaining sites were those with longer post‐surgical durations. Deep‐side sites that lost bone following therapy had a mean pre‐treatment bone loss of 43.6%, a mean tooth‐bone angle of 50.3°, and a mean interradicular width of 2.9 mm. Losing sites were those with shorter post‐surgical durations. The majority of deep‐side sites with <55% pretreatment bone loss remained unchanged. Shallow‐side sites which gained bone following treatment had a greater mean pretreatment bone loss and a smaller tooth‐bone angle than losing sites.
Variation in the composition of gingival inflammatory cell infiltrates
Authors: Johannessen A. C. , Nilsen R. , Kristoffersen T. , Knudsen G. E.
Published: December 2005

Abstract Biopsy specimens were taken at gingivectomy from 18 adult patients undergoing treatment for chronic marginal periodontitis. They were embedded so that the cut surface of the gingiva was parallel to the top of the block to obtain a comprehensive view in a transversal plane of the inflammatory cell infiltrate near the bottom of the pocket. Sections were stained with HES or with toluidine blue for histological description, and acid α‐naphthyl acetate esterase (ANAE) was used to differentially stain T lymphocytes, plasma cells and monocytes/macrophages. Sections stained with HES showed that the density and size of the cell infiltrates varied along the circumference of a tooth over very short distances and on various surfaces on neighbouring teeth. Differential counts of cells stained for ANAE demonstrated great variation in the composition of the cell infiltrates, particularly along the pocket epithelium. The predominating ANAE positive cell type in this area was T lymphocytes, while in the central connective tissue, plasma cells predominated. There was no systematic covariation between the localization of the gingiva (i.e. mesial, facial, etc.) and the composition of the cell infiltrates. The local variation in the composition of the cellular infiltrate most likely reflects local variability in the noxious substances (i.e. plaque composition) within the periodontal pocket, and in the resulting local inflammatory response.
Root exposure in the primary dentition studied in human skulls
Authors: Bimstein E. , Ranly D. M. , Skjonsby S.
Published: December 2005

Abstract The aims of the present study were to examine, on the primary dentition of 75 human dried skulls, the distance from the cemento‐enamel junction (CEJ) to the alveolar bone crest, and to evaluate its relation to developmental age, bone morphology and attrition. The measurements from the CEJ to the alveolar crest were longer for the maxillary teeth, the second molars showed the shortest measurements, while the cuspids showed the longest. Significant positive partial correlations were found between age and the distance from the CEJ to the alveolar crest when controlling for attrition (r=0.64), and between age and attrition when controlling for the distance from the CEJ to the alveolar bone crest (r=0.54). The partial correlation between migration and attrition when controlling for age proved to be not significant (r=0.13). Significant correlations were found between age and the distances from the mental foramen to: the alveolar crest (r=0.90), and to the lower border of the mandible (r=0.97). These findings suggest that root exposure takes place in the primary dentition, as the result of continuous eruption at a faster rate than formation of alveolar bone, presumably to compensate for facial growth.
Immunohistological analysis of gingival lymphocytes in adult periodontitis
Authors: Çelenligil Haviye , Kansu Emin , Ruacan Sevket , Eratalay Kenan , Çaglayan Gürhan
Published: December 2005

Abstract Inflammatory periodontal diseases are mediated by interactions between the dental plaque and the components of the host immune system. This study was designed to analyse the phenotypic properties of gingival lymphocytes in adult periodontitis. Biopsies were obtained from 12 patients and aged between 35 and 55 years. The tissues were processed for both histopathological and immunohistological examinations. Gingival tissue lymphocytes were identified using monoclonal and polyclonal antibodies with the immunoperoxidase technique. All speciments revealed a significant degree of CD3(+) cell infiltration beneath the pocket epithelium, which is located adjacent to the bacterial plaque, compared to that on the oral epithelial side. CD4(+) and CD8(+) cells were evenly distributed within these infiltrates. Numerous HLA‐DR(+) cells were also noted. The majority of plasma cells in the central lamina propria bore IgG isotypes. These findings suggest that T‐cell mediated regulatory mechanisms play an important role in the pathogenesis of adult periodontitis.
Reliability of attachment loss measurements in a longitudinal clinical trial
Authors: Best A. M. , Burmeister J. A. , Gunsolley J. C. , Brooks C. N. , Schenkein H. A.
Published: December 2005

Abstract In order to appropriately carry out a longitudinal assessment of periodontal attachment loss in individuals with untreated periodontitis, reliable criteria for determining “real” changes in attachment level (AL) are required. In the present study, 25 subjects were to be examined every 2 months for up to 2 years to determine changes in AL and to relate clinical and laboratory criteria to such changes. Trained examiners for the study underwent calibration trials to determine inter‐examiner and intra‐examiner reliability both before the study and at intervals during the study. It was found that AL measurements were in agreement within 2 mm more than 95% of the time. The calibration trials provided an estimate of the error in attachment loss measurements, since no “real” attachment loss had occurred. From estimates of measurement error, the probability of false positive changes were determined. It was found that acceptable false positive rates (< 5%) could be achieved if 2 examiners each detected 3 mm change at a given site or if 2 examiners each detected 2 mm change at a site and verified that this change persisted at a subsequent examination. The results of the longitudinal trial were then compared to the probability estimates calculated from the calibration trials. It was found that probabilities of AL changes detected during the longitudinal trial for less stringent conditions than described above (e.g., single examiner, 2 examiners unconfirmed) were similar to previously estimated false positive rates. However, under conditions chosen for confirmation of AL change (2 examiners confirmed), the actual % of examinations in which at least 1 site changed was considerably greater than predicted (28% versus 5%), indicating that true AL change had likely been detected. Thus, detection of AL change with a standard periodontal probe in a longitudinal study is reliable when 2 examiners each detect a change in AL of 3 mm from baseline or when 2 examiners each detect a 2 mm change that is confirmed at a subsequent examination. Furthermore, calibration trials provide a good estimate of expected rates of measurement error during a subsequent longitudinal trial.
Randomized controlled trial of doxycycline in prevention of recurrent periodontitis in high‐risk patients: antimicrobial activity and collagenase inhibition
Authors: McCulloch C. A. G. , Birek P. , Overall C. , Aitken S. , Lee W. , Kulkarni G.
Published: December 2005

Abstract 82 patients with a recent history of periodontal abscesses and/or loss of gingival attachment (GAL) despite active periodontal therapy were enrolled in a double‐blind, randomized, placebo‐controlled trial. Clinical measurements and subgingival scaling were performed every 2 months. If any site exhibited ≥ 2 mm loss of GAL or a periodontal abscess, patients were administered either 100 mg Doxycycline per day for 3 weeks or placebo. During 12 months of monitoring, 55 patients exhibited recurrent active disease and were then randomly assigned to either the Doxycycline or placebo groups. Clinical measurements of GAL and microbiological culture of subgingival bacteria were made at intervals between 1 week and 7 months after completion of the drug regime. Within 7 months, 15 out of 19 patients on placebo exhibited recurrent disease compared to 13 out of 29 patients on Doxycycline, a relative risk reduction of 43% (p < 0.05) for Doxycycline compared to placebo. Minimal inhibitory concentrations of Doxycycline for subgingival plaque samples from active sites ranged between 25–100 μg/ml, which are several fold higher than reported crevicular fluid concentrations for this drug. However gingival crevicular fluid collagenase was inhibited in vitro at concentrations of 5‐10 μg/ml Doxycycline. These data indicate that Doxycycline provides significant risk reduction of recurrent periodontitis in patients with active disease.