bluuebunny/crossref_metadata_2025 huggingface dataset:
Uptake and Impact of Carrier Testing for Cystic Fibrosis
Authors: Decruyenaere Marleen , Evers-Kiebooms Gerry , Denayer Lieve , Welkenhuysen Myriam
Published: April 2003

The first aim of the paper is to review research into the uptake of carrier testing for cystic fibrosis and into the impact of carrier testing on self-esteem, risk perception and reproductive decisions. The second aim is to connect the most important findings to psychological theories and concepts. Thirdly, we infer practical suggestions for genetic counselling. The uptake of genetic testing for CF could be explained by at least three (complementary) interrelated psychological concepts: the (lack of) genetic information, the individual’s health beliefs and the concept of coping with a health threat. Cognitive and/or emotional coping mechanisms played also an important role in preserving self-esteem after a positive carrier test and in the subjective evaluation of the residual risk after a negative test result. Suggestions are given regarding genetic counselling in general and regarding free informed decision making.
Improving Access to and Utilization of Genetic Services in Arizona’s Hispanic Population
Authors: Bridge Marianna , Iden Sarah , Cunniff Chris , Meaney F.John
Published: April 2003

This abstract presents a model project aimed to train community lay health workers about genetics, increase cultural competency of genetic services providers, and provide local access to genetic services in primarily Hispanic communities in the state of Arizona. Health Start, a community-based prenatal outreach program, served as the basis for providing genetic education and services. A genetics training curriculum was developed and training of community lay health workers was provided. Cultural and Spanish language training was provided for all genetic services providers. Pediatric genetics outreach clinics were established in eight communities. Community-based lay health workers eagerly incorporate genetic information into their public health knowledge base, but this may not lead to acceptance of these personnel by local health care providers as sources of referrals for specialized health services such as genetics. Cultural competence training of genetic service providers is enthusiastically accepted and utilized in the provision of locally accessible genetics clinics.
Genetic Testing: Can It Predict the Lived Experience of Individuals and Families? A Personal Testimony
Authors: Powell TraciM.
Published: April 2003

An individual’s and family’s experience with a genetic disease is too complex and diverse to be totally predicted using genetic testing. Stigmatization and discrimination of gene carriers can occur if society chooses to utilize genetic technology to eliminate ‘disease and disability’ without accepting human variation and devoting any possible efforts for ameliorating the life of individuals faced with disabilities. In this paper I use Friedreich’s ataxia (FA) to illustrate some ways in which a disease experience can differ from what is expected from textbook descriptions of a given condition. I describe the expected medical characteristics with FA and some of my own personal experience with the disease as well as that of my family.
Analysis of the Population Structure in Oman
Authors: Rajab Anna , Patton Michael A.
Published: April 2003

Knowledge of a population structure can be a unique aid in planning genetic services. In order to facilitate the development of genetic services in the Sultanate of Oman, a tribal data base has been developed. The historic records of the beginning of the 19th century were used as the basis and were updated with contemporary information. The tribal data base includes tribal names, locations, and the main 185 major tribes and their subsections. Tribal data can be used for health care planning and the development of disease-specific genetic registers if the hospital records also include the tribal name. They may also provide a useful aid in genetic screening and disease prevention programmes, as when specific mutations are found in rare diseases, it is likely that these will be found to be exclusive to specific tribes, and laboratory testing will be greatly simplified. It is likely that similar data bases could be developed elsewhere in the Middle East and in the immigrant communities in Western Europe.
Study of 290 Cases of Polyhydramnios and Congenital Malformations in a Series of 225,669 Consecutive Births
Authors: Stoll Claude G. , Roth Marie-Paule , Dott Béatrice , Alembik Yves
Published: April 2003

Objectives: To provide data on polyhydramnios associated with congenital anomalies in 225,669 consecutive pregnancies. Material and Methods: The information in this study came from births of known outcome recorded in our registry of congenital malformations. Routine ultrasonographic examination was performed. Polyhydramnios was diagnosed ultrasonographically. A case-control study allowed the examination of genetic and environmental causal factors of polyhydramnios associated with congenital malformations. Results: The prevalence of this association was 1.28/1,000 (290 cases). Polyhydramnios associated with congenital malformations was diagnosed prenatally in 44.5% of the cases, 10.3% of the infants were stillborn. Forty-one percent of the cases had more than one malformation, 14.5% had a chromosomal aberration, and 20.0% had multiple malformations that do not constitute a syndrome. The more frequent malformations associated with polyhydramnios were cardiac, digestive, central nervous system, musculoskeletal, and urinary. There was increased parental consanguinity. The incidence of polyhydramnios and congenital anomalies among first-degree relatives was 4.1% and first-degree relatives had more malformations than controls (6.2 vs. 3.2%, p < 0.05). Threatened abortions and diabetes mellitus were significantly more frequent among mothers of children with congenital malformations associated with polyhydramnios than among controls. Conclusions: Our study demonstrated that careful fetal examination has to be performed when polyhydramnios is diagnosed as congenital malformations are often associated with polyhydramnios. We recommend the use of fetal chromosome analysis and careful ultrasonographic examination in every pregnancy complicated by polyhydramnios.
The Role of Voluntary Consumer Organisations in Genetic Services in the United Kingdom
Authors: Kent Alastair
Published: April 2003

This article describes the role of the Genetic Interest Group (GIG), a UK alliance of charities and voluntary groups for families affected by specific genetic disorders, as an advocate for the needs of patients and their families and as an agent of change in the development of genetic services in the UK. GIG now interacts with a wide range of audiences – lay groups, the professional community, policy makers, government and the media – in a variety of different ways, so that the perspective of the ‘end user’ is reflected in decisions about the application of the new genetics in the field of human health.
Plaque and Gingival Status as Indicators for Caries Progression on Approximal Surfaces
Authors: Ekstrand K.R. , Bruun G. , Bruun M.
Published: April 2003

This study aimed to (1) record the plaque and gingival status on sound and carious approximal surfaces and (2) investigate whether the two parameters could predict approximal lesion progression. For this purpose two samples were selected among 18- to 25-year-old patients at the Dental Faculty in Copenhagen. Sample 1 consisted of 45 patients, each having an approximal posterior surface requiring operative treatment and a contralateral approximal space, where both surfaces were radiographically sound. Sample 2 consisted of 25 patients, each having a posterior approximal tooth surface with an enamel/initial dentinal lesion recorded on a bitewing. Plaque and gingival status were classified using 4-point ranked scales. The recordings were performed once on each participant in sample 1. The recordings in sample 2 were repeated 5 times during a 15-month period. In order to assess lesion progression in sample 2, two serial intraoral examinations were performed, i.e. at the beginning and end of the study. Less than 10% of the sound and carious surfaces were recorded as plaque-free, while about 40% had a thick or heavy plaque accumulation. No significant difference was observed between plaque scores on sound and carious surfaces (p = 0.5), in contrast to findings representing the gingival status (p < 0.001). Tooth surfaces requiring operative treatment were associated with bleeding of the gingiva after probing. In sample 2, 3 of the 25 participants did not finish the study. On the remaining participants caries progression was observed in 9 cases (41%), while no progression was observed in 13 cases. Analyses showed that there were no significant differences between plaque scores in cases with caries progression, as compared with no caries progression (p > 0.05). Similar analyses concerning gingival status showed that bleeding of the gingiva was related to cases with progressing caries. Analyses also disclosed no direct association between plaque and gingival status (Spearman correlation coefficient 0.39). Thus, the occurrence of plaque does not have the same predictive power as bleeding after probing in decision-making as to whether or not a lesion progresses.
A Quantitative Light Microscopic Study of the Odontoblast and Subodontoblastic Reactions to Active and Arrested Enamel Caries without Cavitation
Authors: Bjørndal L. , Darvann T. , Thylstrup A.
Published: April 2003

This study describes cellular and microradiographic findings in thin undemineralized enamel-dentine sections from 36 enamel caries lesions from freshly extracted third molars. Lesions activity was determined by clinical examination and the estimated age of the lesion at extraction time. The cellular reactions to the enamel/dentine lesion complex were measured using computerized histomorphometry under the following conditions: (a) the cytoplasm:nucleus ratio of the odontoblast cell; (b) the odontoblast cell:dentinal tubule ratio, and (c) the adjacent predentine area (μm2). The first cellular reactions were observed beneath superficial enamel lesions before visible alterations in dentine mineralization. The cytoplasm:nucleus ratio of the odontoblast cells was markedly reduced, and only active lesions showed evidence of cellular proliferation into the cell-free zone. In more advanced active lesions the affected odontoblast cells had a significantly lower cytoplasm:nucleus ratio compared with the controls. Similar changes were not seen in arrested or slow-progressing lesions. Before onset of tertiary dentine formation there was a positive correlation between odontoblast cell size and predentine formation. Primary odontoblast cells were involved in early tertiary or reactionary dentine formation without odontoblast cell replacement. Reactionary dentine was only seen in active lesions, suggesting that reactions in the dentine/pulp complex are closely associated with the external environment.
A Mathematical Model of the Influence of Salivary Urea on the pH of Fasted Dental Plaque and on the Changes Occurring during a Cariogenic Challenge
Authors: Dibdin G.H. , Dawes C.
Published: April 2003

Urea diffusing from saliva into dental plaque is converted to ammonia and carbon dioxide by bacterial ureases. The influence of normal salivary urea levels on the pH of fasted plaque and on the depth and duration of a Stephan curve is uncertain. A numerical model which simulates a cariogenic challenge (a 10% sucrose rinse alone or one followed by use of chewing-gum with or without sugar) was modified to include salivary urea levels from 0 to 30 mmol/l. It incorporated: site-dependent exchange between bulk saliva and plaque surfaces via a salivary film; sugar and urea diffusion into plaque; pH-dependent rates of acid formation and urea breakdown; diffusion and dissociation of end-products and other buffers (acetate, lactate, phosphate, ammonia and carbonate); diffusion of protons and other ions; equilibration with fixed and mobile buffers; and charge-coupling between ionic flows. The Km (2.12 mmol/l) and Vmax (0.11 μmol urea/min/mg dry weight) values for urease activity and the pH dependence of Vmax were taken from the literature. From the results, it is predicted that urea concentrations normally present in saliva (3–5 mmol/l) will increase the pH at the base of a 0.5-mm-thick fasted plaque by up to 1 pH unit, and raise the pH minimum after a sucrose rinse or sugar-containing chewing-gum by at least half a pH unit. The results suggest that plaque cariogenicity may be inversely related to salivary urea concentrations, not only when the latter are elevated because of disease, but even when they are in the normal range.
A Descriptive Report of the Effects of a 16-Month Xylitol Chewing-Gum Programme Subsequent to a 40-Month Sucrose Gum Programme
Authors: Mäkinen K.K. , Hujoel P.P. , Bennett C.A. , Isokangas P. , Isotupa K. , Pape Jr. H.R. , Mäkinen P.-L.
Published: April 2003

A previous caries trial (Belize studies) involved the usage of sucrose chewing-gum for a period of 40 months in one group of initially 10-year-old subjects in an environment of high sugar consumption, high caries activity, and limited access to restorative care. After the termination of the 40-month supervised sucrose gum usage, the 109 subjects of the original sucrose group retrieved at the endpoint of the original trial were invited to participate in a xylitol chewing-gum programme (involving the usage of the ‘100% pellet-shaped formular’) for 16 months. The average daily consumption level of xylitol was up to 14 g per subject, normally used in seven daily chewing episodes. Although most subjects used chewing-gum at schools and received their gum portions from a school official, gum chewing during these 16 months was mostly unsupervised. After 16 months, 83 subjects (76%; mean age 14.9 years) were retrieved. The caries status of these subjects was examined by the same calibrated, blinded examiners as in the original trial. To mask the examiners, 141 similar non-participating subjects were recruited from the same school classes and were examined in a random order with the gum-using subjects, according to the same standard routine. The intensified xylitol gum usage for 16 months was associated with a reduction of the mean DMFS score from 10.9 (at 40 months) to 9.3 (at 56 months, p = 0.0013) and a reduction in caries rate from 20.1 caries onsets per 1,000 surface-years (40-month period average rate) to 10.2 caries onsets per 1,000 surface-years. The reduction in DMFS score resulted mostly from the change in the D component of the index and possibly reflected a stabilisation of the caries process and rehardening of some caries lesions to a non-progressive carious state.
The Effect of a Knowledge-based, Image Analysis and Clinical Decision Support System on Observer Performance in the Diagnosis of Approximal Caries from Radiographic Images
Authors: Firestone A.R. , Sema D. , Heaven T.J. , Weems R.A.
Published: April 2003

The aim of this study was to investigate the effect of a knowledge-based image analysis and clinical decision support system (CariesFinder™, CF) on diagnostic performance and therapeutic decisions. The study material consisted of radiographic images of 102 approximal surfaces, 35 sound, 67 caries (25 caries and cavitated and 42 caries). Sixteen general practitioners were presented with (1) radiographic film images and (2) digital filmless images with the results of CF. The viewers were asked to respond whether approximal caries was present and whether a restoration was indicated. Responses were analyzed for accuracy, sensitivity, specificity and agreement. Further, the practitioners were ranked according to the accuracy of their restorative decisions and assigned to ten overlapping groups of 7 practitioners. For each group the diagnostic and therapeutic decisions were then examined for unanimity. The parameters of accuracy, sensitivity and specificity were then established for each group based on only unanimous, correct decisions. The diagnostic and therapeutic accuracy of CF alone was equal or superior to the decisions of the practitioners viewing film images alone. For unanimous decisions, CF alone was more accurate than the most accurate group of practitioners and made fewer incorrect decisions to restore non-cavitated surfaces than the practitioners. In general, dental practitioners viewing the results of CF significantly increased their ability to diagnose caries correctly, their overall diagnostic accuracy, and their ability to recommend restorations for cavitated surfaces. There was a decrease in the accuracy of their restorative decisions overall and in the specificity in particular.
Prevalence and Severity of Dental Caries in 12-Year-Old Children in Kaunas, Lithuania 1995
Authors: Machiulskiene V. , Nyvad B. , Baelum V.
Published: April 2003

In order to evaluate suitable strategies for control of dental caries, a longitudinal study of caries progression has been initiated among 12-year-old children in Kaunas, Lithuania. The aim of the present paper was to describe the baseline caries situation in a sample of 12-year-olds, who had been examined using caries diagnostic criteria which differentiate between active and inactive caries lesions at both the cavitated and non-cavitated levels. The mean fluoride concentration in the drinking waters of Kaunas is 0.16 mg/l. A total of 889 children in the 6th grade from seven selected schools were examined. Each tooth surface of all permanent teeth was classified according to one of the following criteria: 0 = sound; 1 = active, surface intact; 2 = active, surface discontinuity; 3 = active, cavity; 4 = inactive, surface intact; 5 = inactive, surface discontinuity; 6 = inactive, cavity; 7 = filled; 8 = filled with inactive lesion; 9 = filled with active lesion; X = extracted. Distinction between active and inactive lesions was made on the basis of a combination of visual and tactile criteria. Virtually all children (99.7%) had experienced at least 1 DMF surface. The mean DMFS was 15.8. Half of the mean caries experience consisted of surfaces with active lesions (7.9), of which two thirds (4.9) were non-cavitated. The mean number of surfaces with non-cavitated inactive lesions was 4.4. The mean DMFT constituted 7.9; 95% of all first molars were affected, followed by the second molars (61%). A comparison of the caries profile according to the present caries diagnostic criteria with those recommended by WHO revealed that the WHO criteria yielded much lower DMFS and DMFT values, because this scoring system does not include non-cavitated caries lesions. The high level of non-cavitated active caries lesions suggests that in this population caries may to a large extent be controlled by simple preventive measures including use of topical fluorides.
The Effect of Intrinsic Fluoride in Cows’ Milk on in vitro Enamel Demineralization
Authors: Kahama R.W. , Damen J.  J.  M. , ten Cate J.  M.
Published: April 2003

The fluoride concentration in cows’ milk has been reported to vary with the fluoride levels in drinking water but it seldom exceeds 0.5 μg/ml. This raised a question as to whether any caries-protective effect could be attributed to the intrinsic fluoride of milk. Two samples of cows’ milk with intrinsic fluoride concentrations of 0.03 and 0.3 μg/ml, respectively, were assessed for their protective effect on enamel in an in vitro demineralization model at relatively severe and mild acidic challenges (pH 4.6 and 5.0, respectively). Polished enamel discs were incubated individually in 5.0 ml of demineralization solution for 20 h per day alternated with 1-hour incubations in 1.0 ml of milk or control buffers: group 1, demineralization solution only (negative control); group 2, milk with 0.03 μg/ml fluoride; group 3, milk with 0.03 μg/ml fluoride; supplemented with NaF to 0.3 μg/ml fluoride; group 4, milk with 0.3 μg/ml fluoride; group 5, 0.3 μg/ml fluoride in 20 mM HEPES, pH 6.7; group 6, milk with 0.03 μg/ml fluoride supplemented with NaF to 5.0 μg/ml fluoride (positive control). The solutions were renewed each day and the calcium concentration in the demineralization solutions was followed during 4 days. The results showed that the protective effect of intrinsic milk fluoride on enamel is limited by the severity of the acidic challenge: There was a significant inhibition of the demineralization in groups 3–6 compared to groups 1 and 2, but only at pH 5.0 (p < 0.0001) and not at pH 4.6 (p = 0.2). The organic components of milk had limited protection against demineralization because milk and HEPES with the same fluoride concentration gave similar results. The 36% reduction in calcium loss at pH 5.0 by treatment with milk with only 0.3 μg/ml fluoride is an indication that intrinsic milk fluoride has some caries-protective properties.
Detection, Diagnosing, Monitoring and Logical Treatment of Occlusal Caries in Relation to Lesion Activity and Severity: An in vivo Examination with Histological Validation
Authors: Ekstrand K.R. , Ricketts D.N.J. , Kidd E.  A.  M. , Qvist V. , Schou S.
Published: April 2003

The aims of the present study were to investigate the ability of 3 experienced clinicians to detect occlusal carious lesions, assess their depth, diagnose their activity and define a logical management for each lesion. The material consisted of 35 third molars scheduled for extraction or surgical removal making it possible to validate the accuracy of the clinical recordings histologically. Examinations were carried out at baseline and after 4 months in order to monitor lesion progression. At the first visit a radiograph was taken; the number of filled surfaces was counted and the oral hygiene assessed generally and by disclosing occlusal plaque of the tooth under examination. After cleaning the occlusal surface caries was recorded in a selected investigation site using a visual ranked caries scoring system, as well as an electrical conductance recording (ECM). Apart from counting fillings and taking new radiographs the same procedure was performed at the second visit, which then was followed by extraction of the tooth. After sectioning the tooth lesion depth was recorded, and lesion activity, based on acid production, was assessed using methyl red dye. Lesion activity was also judged by means of polarized light microscopic examinations of the sections. Results showed strong relationships between the visual, ECM and radiographic assessments and both lesion depth and lesion activity. In contrast, all other parameters were poorly related to lesion activity. Changes in visual assessments and in conductance readings from first to second examination were poorly associated with lesion activity. In conclusion, clinicians are able to detect lesions, predict activity and severity and define a logical management of occlusal caries on the basis of a single examination.
Association between Caries Prevalence and Clinical, Microbiological and Dietary Variables in 1.0 to 2.5-Year-Old Brazilian Children
Authors: Mattos-Graner R.O. , Zelante F. , Line R.C.S.R. , Mayer M.P.A.
Published: April 2003

The association between caries prevalence and clinical (presence of visible plaque in the labial surfaces of maxillary incisors), microbiological (salivary levels of mutans streptococci) and dietary variables was evaluated in 142 1.0- to 2.5-year-old children attending public day-care nurseries in the city of Piracicaba – São Paulo. A significant difference in caries prevalence was observed between those children with and without visible plaque (χ2 = 12.08, p < 0.001). The mean ds (decayed surfaces) was significantly higher in children with visible plaque on the maxillary incisors than in children without it (p < 0.001). Mutans streptococci were detected in 114 (80.3%) of the children. A significantly higher caries prevalence was observed in children with high levels of mutans streptococci compared to children with low levels (χ2 = 28.67, p < 0.001). The mean ds was significantly higher in children with levels of mutans streptococci greater than 50 CFU when compared to children with 0 CFU or 1–50 CFU of mutans streptococci (p < 0.05). Children who were either never breast-fed or only until 3 months exhibited a significantly higher caries prevalence than those breast-fed for a longer time (χ2 = 4.11, p < 0.05). A significantly higher caries prevalence was also observed between children that used bottle containing milk with sucrose and cereal than children using bottle with milk with or without sucrose (χ2 = 6.24, p < 0.05). Children who started to eat salty meals at or after 7 months of age showed a significant higher caries prevalence than children who started earlier (χ2 = 10.30, p < 0.01). These data support the evidence of an association between caries prevalence in young children and mutans streptococci levels, clinical and dietary factors.
Hydrolysis of CaHPO4 in Sodium Fluoride Solutions at 37.4 °
Authors: Martin Roger I. , Brown Paul W.
Published: April 2003

A possible chemical process occurring during caries reversal is conversion of acidic calcium phosphates to apatite. The role of fluoride in this process is of particular interest. The effects of fluoride on the rate of CaHPO4 hydrolysis at 37.4 °C were studied by a multimethod analysis involving X-ray diffraction, analyses of variations in solution chemistry, and observation of microstructural evolution. Hydrolysis in low NaF concentrations results in the formation of discrete fluorapatite crystals on the surfaces of the CaHPO4 crystallites. At CaHPO4/NaF molar ratios from approximately 9 :1 to 10 : 2, fluorapatite formed in approximately 3 h as the only crystalline product and complete hydrolysis of CaHPO4 occurred; a pH value as low as 2.4 was attained with solution species being predominantly sodium phosphate. At NaF concentrations beyond those which result in pH minima, fluorapatite and CaF2 are the crystalline products. At 0.6 M NaF, pseudomorphs composed of fluorapatite and CaF2 crystals form without developing morphologies characteristic of individual fluorapatite and CaF2 crystals. CaHPO2 can hydrolyze completely to fluorapatite and CaF2 within a few hours depending on NaF concentration and liquid-to-solids ratio.
Developmental Enamel Defects in Children with Different Fluoride Supplementation – a Follow–Up Study
Authors: Hiller K.-A. , Wilfart G. , Schmalz G.
Published: April 2003

The intake of fluorides with water, food, dental fluoride preparations, or in particular fluoride supplements, such as NaF tablets, may lead to dental fluorosis. In the present study conducted in a nonfluoridated area in Germany, developmental enamel defects were examined using the Modified Developmental Defects of Enamel Index (Mod DDE Index), which subdivides enamel defects into the categories demarcated (Mod DDE score 1) and diffuse (Mod DDE score 2) opacities and hypoplasia (Mod DDE score 3). 158 children, between 8.5 and 10 years old, were assigned to three examination groups, defined by three different fluoride tablet programs. The children in all three examination groups, F1, F2, and F3, had received 0.25 mg F–/day up to the age of 2 years, F1 and F3 from birth on, F2 beginning with the 7th month of life. F1 and F2 received 0.5 mg F–/day during the 3rd and 0.75 mg F–/day during the 4th and 5th year of life. For F3, beginning with the 3rd year of life, no further recommendations were made. 158 sociodemographically matched children living in a neighboring town served as controls and did not take part in any structured fluoride supplementation program. The proportions of children with Mod DDE scores 1, 2, or 3 at least in one index tooth were significantly higher in the examination groups (40%) than in the control group (20%). Also, the proportions of children with Mod DDE score 2 at least in one index tooth were significantly higher in the examination groups (18%) than in the control group (8%). The proportions of children with Mod DDE score 1 at least in one index tooth were 25% in the examination groups and 17% in the control group. No Mod DDE score 3 was found. Not more than 5% of the children in each group had 50% of their teeth with Mod DDE score 1, 2, or 3. The proportions of teeth per child with Mod DDE score 2 were significantly higher in the examination group than in the control group. While uncontrolled variables cannot be excluded, the observed differences between the experimental and control groups may be attributed to the ingestion of fluoride tablets in the experimental group.
Effect of Toothpicks with and without Fluoride on De– and Remineralization of Enamel and Dentine in situ
Authors: Kashani H. , Birkhed D. , Arends J. , Ruben J , Petersson L.G. , Odelius H.
Published: April 2003

The aim of this investigation was to study the effect of the interproximal use of fluoride (F)–impregnated and non–impregnated birch toothpicks on the degree of de– and remineralization of enamel and dentine in situ. Ten volunteers with complete dentures in the upper jaw participated. Each subject had four specimens: (1) sound enamel, (2) demineralized enamel, (3) sound dentine and (4) demineralized dentine; placed pairwise at two approximal sites (15/16 and 25/26) of the maxillary prosthesis. The study involved three test periods (A, B and C), each lasting 4 weeks. In A, the subjects used F toothpicks (impregnated in 4% NaF) and, in B, nonimpregnated toothpicks 3 times daily. During period C, no toothpicks were used. Dentifrice or other F–containing products were not allowed during the 4–week periods. Transversal microradiography was used to determine lesion depth (ld) and mineral loss (ΔZ). The results revealed that all the sound samples lost mineral during the three experimental periods; ΔZ for both enamel and dentine was less for A and B compared with C (p<0.01) and less for A compared with B and C for dentine (p<0.05, p<0.01). The demineralized samples also lost mineral, apart from dentine, during periods A and B, i.e. when F–impregnated and non–impregnated toothpicks were used; ld for enamel and ΔZ for dentine were less for A compared with C (p<0.05). Four weeks' use of toothpicks, especially F–impregnated toothpicks, thus reduces the demineralization of enamel and dentine at approximal sites in situ.
A Light Microscopic Study of Odontoblastic and Non–Odontoblastic Cells Involved in Tertiary Dentinogenesis in Well–Defined Cavitated Carious Lesions
Authors: Bjørndal L. , Darvann T.
Published: April 2003

This study examines cellular and microradiographic findings in thin, undemineralized sections of 46 cavitated lesions, that were clinically well–defined with respect to lesion activity and estimated lesion age at extraction time. The progressive stages of surface breakdown ranged from enamel cavitation to larger dentine exposures classified as closed and open lesion environments. Measurements of the following parameters were performed using computerized image processing software: (a) the cytoplasm:nucleus ratio of primary odontoblast cells; (b) the cell:dentinal tubule ratio; (c) the adjacent predentine area (μm2), and (d) the cytoplasm: nucleus ratio of non–odontoblastic cells, and secondary odontoblast–like cells, where estimation of these cell types were based on structural criteria. In active enamel cavitated lesions, reduced odontoblast–predentine regions and indistinct subodontoblastic regions were noted. During initial dentine exposures, non–odontoblastic cells along the pulp–dentinal interface were observed as well. The first indication of tertiary dentine was seen in old lesions with exposed dentine. The tertiary dentine appeared more atubular in the closed/active lesions than in the open/slow–progressing lesions. The involved odontoblastic cells in tubular tertiary dentine in small open/slow–progressing lesions were comparable to the primary odontoblast cells, however, new dentinal tubules were also noted presenting a mixture between reactionary and reparative dentinogenesis. In close/active lesions non–primary odontoblastic cells were aligning the atubular tertiary dentine, whereas well–defined signs of secondary odontoblast–like cells were first seen in larger open lesions, producing tubular tertiary dentine. In conclusion, a strong relationship between external lesion environments and corresponding different formations of tertiary dentine was noted in advanced cavitated lesions. It is additionally suggested that the stimulation of tubular tertiary dentine could be a closely related reaction when an active lesion complex changes into a slower progressing lesion environment.
Posteruptive Changes of Electrical Resistance Values in Fissure Enamel of Premolars
Authors: Schulte Andreas , Gente Michael , Pieper Klaus
Published: April 2003

In studies about 15–25% of the caries–free teeth proved to have as low electrical resistance values as carious teeth, due probably to incomplete enamel maturation. It was the aim of the present prospective clinical study to investigate, if an increase in electrical resistance values could be observed after the eruption of premolars. The electrical resistance measurements were performed in children who were patients of the Dental School of the University of Marburg, Germany. The first measurement was made when a premolar was erupting or when it had erupted within 12 months before. The electrical resistance measurements were repeated every 3–6 months until the 24th posteruptive month. The measuring device consisted of an AC ohmmeter modified by Gente indicating the real component of the impedance and employing a frequency of 500 Hz and an amplitude of about 1 μA. For erupting teeth a mean resistance value of 17±15 kohm was computed when the contact fluid had been NaCl (A). The corresponding values were 72±51 kohm when distilled water (B) had been applied and 392±374 kohm when the initially saliva–coated teeth had briefly been dried (C). The mean resistance values of the premolars increased continuously from the eruption up to the 15th posteruptive month. This observation was independent of the three modes of measuring that had been used. It is concluded that enamel maturation leads to an increase in electrical resistance. To improve accuracy of caries diagnosis with electrical resistance measurements, the posteruptive age of teeth should be taken into account. In addition, electrical resistance measurements offer the opportunity to observe enamel maturation in vivo noninvasively.
The Relationship between Habitual Clove Cigarette Smoking and a Specific Pattern of Dental Decay in Male Bus Drivers in Jakarta, Indonesia
Authors: Soetiarto F.
Published: April 2003

This study has been conducted to establish the relationship between habitual smoking of clove cigarettes and a specific type of dental decay. A retrospective cohort study of 1,160 bus drivers in Jakarta who smoked clove cigarettes and non–smokers showed that a specific type of decay occurs in terms of form, location and pathology. The prevalence was 55.8%. The type of decay is affected by the number of years of smoking and the number of cigarettes smoked each day. Thirty–two percent of the lesions were on the buccal surfaces of the upper teeth, 39.3% on the buccal surfaces of the lower teeth, and 18% of palatal surfaces were affected. The prevalence of clove cigarette caries was related to years of smoking and numbers of cigarettes smoked per day. Of the men who smoked 10 years or less, 27% had caries. The prevalence increased to 79.6% for those smoking for 11–15 years. For those smoking for more than 15 years the prevalence was 89.3%. The relative risk of those smoking 7–12 cigarettes a day was 2.66 (p<0.0001) compared to those smoking 0–6 cigarettes a day. The relative risk increased to 3.19 in those smoking 13–18 cigarettes and 2.96 (p<0.0001) in men smoking more than 18 cigarettes per day.
Caries Prevention in a Community–Dwelling Older Population
Authors: Powell L.V. , Persson R.E. , Kiyak H.A. , Hujoel Ph.P.
Published: April 2003

A clinical trial was conducted to compare the effect of different caries–preventive strategies on caries progression in lower–income, ethnically diverse persons 60 years of age and older. Two hundred and ninety–seven subjects were randomized into one of five experimental groups. Group 1 received usual care from a public health department or a private practitioner. Group 2 received an educational program of 2 h duration implemented twice a year. Group 3 received the educational program plus a 0.12% chlorhexidine rinse weekly. Group 4 received the education and chlorhexidine interventions and a fluoride varnish application twice a year. Group 5 received all the above interventions as well as scaling and root planing every 6 months throughout the 3–year study. A carious event was defined as the onset of a carious lesion, a filling, or an extraction on a surface which was sound at baseline. Two hundred and one subjects remained in the study for the 3–year period. Groups that received usual intraoral procedures (groups 3, 4, and 5) had a 27% reduction for coronal caries events (p = 0.09) and 23% for root caries events (p = 0.15), when compared to the groups that received no intraoral procedures (groups 1 and 2). Routine preventive treatments may have had only a small–to–moderate effect upon caries development.
A Comparison of Clinical and Radiographic Caries Diagnoses in Posterior Teeth of 12–Year–Old Lithuanian Children
Authors: Machiulskiene V. , Nyvad B. , Baelum V.
Published: April 2003

Bite–wing radiography has been recommended for use in adolescents as clinical examinations alone may lead to underestimation of carious lesions in approximal and occlusal surfaces. The aim of this study was to describe the relationship between clinical and radiographic caries diagnoses among 12–year–old Lithuanians using a new clinical scoring system which differentiates between cavitated and non–cavitated caries lesions. Eight hundred and seventy–two children were examined clinically and two standardized posterior bite–wing radiographs were taken of each participant. Bite–wing radiography contributed significantly to the total number of lesions diagnosed only at the dentin level in approximal surfaces. Clinical examination performed better than radiographic examination at the non–cavitated/enamel level, particularly on occlusal surfaces. Less than 2% of the clinically sound surfaces were diagnosed with dentin lesions/fillings radiographically. When using the cavitated level of clinical diagnosis, the frequency of ‘hidden’ caries lesions increased from 1.9 to 2.9% in approximal surfaces, and from 1.7 to 5.2% in occlusal surfaces. The intra–examiner reliability data for the clinical and radiographic recordings supported the conclusion of an additional diagnostic value of bite–wings only for approximal surfaces. The findings demonstrate that the diagnostic yield of bite–wing radiography is higher for approximal than for occlusal surfaces. The efficacy of bite–wings depends on the refinement of the clinical caries diagnostic criteria. ‘Hidden’ caries does not seem to be a major problem when the clinical caries diagnostic criteria include non–cavitated diagnoses.
Effect of Apis mellifera Propolis from Two Brazilian Regions on Caries Development in Desalivated Rats
Authors: Koo H. , Rosalen P.L. , Cury J.A. , Park Y.K. , Ikegaki M. , Sattler A.
Published: April 2003

The purpose of the present study was to evaluate the effect of Apis mellifera propolis collected from two regions of Brazil on caries development in desalivated rats. Ethanolic extracts of propolis (EEP) were prepared from crude propolis samples collected in Minas Gerais state (MG), southeastern Brazil, and Rio Grande do Sul state (RS), southern Brazil. The flavonoid composition of EEP was analyzed by high–performance thin–layer chromatography (HPTLC) and reversed–phase high–performance liquid chromatography (HPLC). For the animal study, 30 specific pathogen–free Wistar rats were infected with Streptococcus sobrinus 6715 and surgically desalivated. The rats were randomly divided into three groups which were treated with 80% ethanol (control), EEP from MG and EEP from RS. The animals were placed in a König–Höfer programmed feeder and received 17 meals of diet 2000 daily at hourly intervals. The solutions were applied on the rat molars (25 μl on molars of each quadrant) twice a day, by using graduate syringes. After 3 weeks, the animals were killed by CO2 asphyxiation. For microbial assessment, the left jaw was removed and sonicated in 154 mM NaCl solution. Dental caries was evaluated according to Larson’s modification of Keyes’ system. The HPTLC patterns and HPLC profiles demonstrated that both quality and quantity of flavonoid aglycones of EEP from MG were different compared to EEP from RS. In general, it is apparent that EEP from RS contained the highest concentrations of pinocembrin, chrysin, acacetin and galangin. The group of animals treated with EEP from RS showed the lowest smooth–surface and sulcal caries scores as well as less caries severity in smooth–surface and sulcal lesions, and these data were statistically different when compared with the control group. The group treated with EEP from MG only demonstrated a significant difference in the severity of sulcal lesions when compared to the control group. The percentage of S. sobrinus was lower in the groups treated with EEP, but did not differ statistically from the control group. The results showed that the cariostatic effect of propolis depends on its composition, and consequently the region of collection of propolis samples.
Fingernail Fluoride: A Method for Monitoring Fluoride Exposure
Authors: Whitford G.M. , Sampaio F.C. , Arneberg P. , von der Fehr F.R.
Published: April 2003

This work was based on the hypothesis that fingernail clippings can be used as a biomarker for the subchronic exposure to fluoride. The results provide data on factors that may affect the concentration of fluoride in fingernail clippings as determined with the electrode following HMDS–facilitated diffusion. The following variables had only minor or no effects on the concentrations: (1) the surface area of the clippings (intact, minced or filed into powder) that were placed into the diffusion dishes; (2) soaking in deionized water for up to 6 h; (3) soaking in fluoridated water (1.0 ppm) for 2 h, and (4) removal of the organic material of nails by dry ashing. Fingernail fluoride concentrations were approximately 50% higher than those in toenails. A 1–month period of increased fluoride intake by one of the authors resulted in significant increases in fingernail fluoride concentrations after a lag time of approximately 3.5 months. The fluoride concentrations in fingernail clippings obtained from three groups of Brazilian children were directly related to the concentrations in the drinking water (0.1, 1.6 or 2.3 ppm). The results indicate that: (1) HMDS–facilitated diffusion completely separates fluoride from intact nail clippings, so the need for ashing or other preparative methods is obviated; (2) fingernail fluoride is derived mainly from the systemic circulation, and (3) fluoride intake is reflected by the concentrations in fingernails.
Measurements of the Wettability of Protein–Covered Hydroxyapatite Surfaces
Authors: Kawasaki K. , Kambara M. , Matsumura H. , Norde W.
Published: April 2003

We developed a new method (dropping time method, DTM) to investigate the wettability of a surface of a protein layer adsorbed on glass plates in aqueous solution. However, the previous setup of DTM can only be utilized for optically transparent materials. In this study, we have extended the method to optically nontransparent materials such as hydroxyapatite plates. DTM is based on measuring the dropping time of a liquid film along a protein–covered surface when this surface is instantaneously vertically removed from the protein solution. The intensity of the reflected light beam depends on the presence of a liquid film on the surface. This allows to estimate the movement of the liquid film along the sorbent surface. Thus, the extended DTM can be used for determining the wettability of optically nontransparent solid plates. The adsorption behavior of four proteins (albumin, lysozyme, β–lactoglobulin, ovalbumin) on a hydrophobic hydroxyapatite plate in water was studied by this method. When adsorbed from a protein solution of high concentration, the surfaces of adsorbed proteins, except ovalbumin, were fairly hydrophilic; this hydrophilicity was already attained at the initial stage of the adsorption process. The surface of ovalbumin on hydroxyapatite was more hydrophobic than those of the other proteins, and the hydrophilicity increased with the protein adsorption process. At low protein concentration, the hydrophilicity increased in the course of the adsorption process. The change in hydrophilicity with time depends on the kind of protein. Hen’s egg lysozyme is more hydrophilic and the time to reach saturation is shorter than for the other proteins. The processes of increasing hydrophilicity of the surface of human serum albumin, β–lactoglobulin and ovalbumin are similar. However, for β–lactoglobulin hydrophobicity at adsorption saturation is stronger than for human serum albumin and ovalbumin. Thus, using DTM it is shown that the hydrophilicity of the surface of adsorbed protein on hydroxyapatite depends strongly on the kind of protein.
Rates of Mineral Loss in Human Enamel during in vitro Demineralization Perpendicular and Parallel to the Natural Surface
Authors: Anderson P. , Elliott J.C.
Published: April 2003

Human enamel is a structurally anisotropic material. The aim of this study was to investigate whether this structural anisotropy is reflected in the demineralization behaviour of enamel. Kinetics of demineralization of in vitro caries lesions with the direction of acid attack perpendicular to the natural surface of dental enamel from human premolar teeth were compared with kinetics when demineralized parallel to this surface. Pairs of enamel samples from the same tooth were demineralized under identical conditions. Loss of mineral with time was very nearly linear for both directions (consistent with the rate–controlling step being reaction at the advancing front rather than transport processes), but the perpendicular rate was, on average, about 14% higher than the parallel rate. The rate of demineralization parallel to the surface increased from the natural surface to the enamel–dentine junction by 10–25%, depending on sample. The origin of fine structure and slight departures from linearity in the loss of mineral with time plots are discussed. Mineral masses per unit area were determined from absorption of a 15–μm diameter X–ray beam using photon (AgKα) counting methods.
Polarization–Sensitive Optical Coherence Tomography of Dental Structures
Authors: Baumgartner A. , Dichtl S. , Hitzenberger C.K. , Sattmann H. , Robl B. , Moritz A. , Fercher A.F. , Sperr W.
Published: April 2003

Optical coherence tomography (OCT) has been developed during the last 10 years as a new noninvasive imaging tool and has been applied to diagnose different ocular and skin diseases. This technique has been modified for cross–sectional imaging of dental structures. In this first preliminary study the technique was applied to obtain tomographic images of extracted sound and decayed human teeth in order to evaluate its possible diagnostic potential for dental applications. Classical OCT images based on reflectivity measurements and phase retardation images using polarization–sensitive OCT were recorded. It was demonstrated that polarization–sensitive OCT can provide additional information which is probably related to the mineralization status and/or the scattering properties of the dental material. One of the attractive features of OCT is that it uses near–infrared light instead of ionizing radiation. Furthermore, high transversal and depth resolution on the order of 10 μm can be obtained. Present limitations, e.g. the limited penetration depth, and possible solutions are discussed.