bluuebunny/crossref_metadata_2025_split huggingface dataset:
Different Patterns of the Fall of Impedance as the Result of Heating During Ostial Pulmonary Vein Ablation: Implications for Power Titration
Authors: REITHMANN CHRISTOPHER , REMP THOMAS , HOFFMANN ELLEN , MATIS TOMAS , WAKILI REZA , STEINBECK GERHARD 
Published: December 2005

Background: A variety of strategies have been proposed to avoid the risks of pulmonary vein ablation for atrial fibrillation. The fall of impedance during radiofrequency catheter ablation can be used as a real time measure of tissue heating. The aim of this study was to analyze the impedance fall during ostial pulmonary vein ablation and to evaluate whether adjusting power to the fall of impedance may contribute to a reduction of the risk of complications.
Methods: Analysis of biophysical parameters of ablation and determination of ostial diameters during follow‐up were performed in 70 patients undergoing impedance‐guided segmental ostial pulmonary vein ablation. Repeat radiographic angiography, local electrograms, and baseline impedance were the criteria to define the position of the 4‐mm electrode tip at atrial sites or inside the proximal pulmonary veins.
Results: Energy application inside the proximal pulmonary veins led to an increased impedance fall inside the first 5–10 mm of the pulmonary veins (1.1 ± 0.5 Ω/W) as compared to ablation at atrial sites (0.7 ± 0.3 Ω/W) (P < 0.01). The analysis of temperature and impedance fall during ostial ablation demonstrated an increased impedance fall with heating at sites inside the proximal pulmonary veins (1.5 ± 0.6 Ω/ °C) as compared to atrial sites (1.2 ± 0.5 Ω/ °C) (P < 0.001). The regression lines analyzing these correlations indicated that adjusting power to a maximum impedance fall of 20 Ω would limit heating at pulmonary venous sites to lower temperatures (average maximum temperature: 48 °C) than at atrial sites (average maximum temperature: 63 °C). The ablation strategy used for segmental ostial ablation in 70 patients, which involved power limitation to a maximum impedance fall of 20 Ω, allowed isolation of 89% of targeted pulmonary veins with a low rate of impedance rises (0.3% of applications). No pulmonary vein stenoses >30% were detected by follow‐up computed tomography analysis.
Conclusions: An increased impedance fall as the result of heating during ostial ablation was found inside the proximal pulmonary veins as compared to atrial sites. Adjusting power to the fall of impedance during segmental ostial pulmonary vein ablation contributes to the prevention of overheating inside the pulmonary veins and may lower the risk of coagulum formation and pulmonary vein stenosis.
The effect of a preventive programme on dental plaque, gingivitis and caries in schoolchildren. Results after one and two years
Authors: Axelsson Per , Lindhe Jan 
Published: December 2005

Abstract The effect on plaque, gingivitis and dental caries of regularly repeated professional mechanical tooth cleaning combined with topical application of monofluoro‐phosphate was tested in a group of 192 schoolchildren, 7–14 years of age, during a 2‐year trial. They were divided into test and control groups.A baseline examination revealed that the test and control groups had a very similar oral hygiene status, degree of gingival inflammation and caries experience. Once every second week during the 2‐year period the children of the test groups were given professional oral prophylaxis including careful tooth cleaning and topical application of 5 % sodium mono‐fluorophosphate. Once every month, the children of the control groups brushed their teeth at school, under supervision, using a 0.2 % sodium fluoride solution.The results after 1 and 2 years of experiment indicate that the test group children had low Plaque Index scores (∼ 0.3), only negligible signs of gingivitis (∼ 0.25) and very low caries increment (0.1 new carious surface per year). The control group children had higher Plaque Index scores (∼ 1.0), showed signs of gingivitis (∼ 0.75), and developed on an average 3.1 new carious surfaces per year.It is suggested that the efficacy of public health programmes, based on professional tooth cleaning and topical fluoride administration, should be tested in larger groups of children and adults.
Effect of professional tooth cleaning on healing after periodontal surgery
Authors: Nyman Store , Rosling Bengt , Lindhe Jan 
Published: December 2005

Abstract The investigation was undertaken to find out whether favourable conditions for healing after periodontal surgery would develop in patients whose oral hygiene was professionally maintained at a high standard. The study was performed on 20 patients with advanced periodontal disease. Following an initial examination, comprising plaque index and gingival index scoring, measurement of pocket depths and loss of attachment, the patients were randomly distributed between a test and a control group. The patients first received detailed instructions for oral hygiene and were then subjected to periodontal surgery with the reverse bevel flap procedure. After surgery, the patients of the test group received professional cleaning of the teeth once every 2 weeks. The patients of the control group were recalled for scaling of the teeth once every 6 months. All patients were re‐examined after 6, 12 and 24 months.It was found that the control patients were unable to maintain a high standard of oral hygiene with the result that the treatment of the periodontal disease failed. The patients of the test group maintained a high standard of oral hygiene, and the treatment of the periodontal disease was, therefore, successful.
Plaque‐removing effect of a toothbrush, dental floss, and a toothpick
Authors: Schmid Max O. , Balmelli Oreste P. , Saxer Ulrich P. 
Published: December 2005

Abstract The ability of three different oral hygiene devices to remove 2‐day‐old bacterial deposits was evaluated on 21 young adults with healthy periodontia. On buccal tooth surfaces, the cleaning effect of a multitufted nylon brush was superior to that of a wooden toothpick or unwaxed denial floss. On lingual surfaces, the toothpick was as effective as the brush. On the visible portions of proximal surfaces, all three devices were equally efficient.A combined cleaning exercise with all three instruments together yielded significantly hotter results than did the use of each single device. Eight subjects were able to remove all disclosable deposits.
Radiographs in periodonties
Authors: Lang Niklaus P. , Hill Roger W. 
Published: December 2005

Abstract Intraoral radiographs are widely used in periodontal diagnosis and research. However, accurate radiographic interpretation is only possible with high quality images. Some of the technical and geometric variables to consider have been presented.Early periodontal lesions are not detected in radiographs. The amount of periodontal destruction in more advanced disease is generally underestimated. The accurate topography of periodontal pockets and the buccal and lingual aspects of the teeth cannot be visualized. Clinical probing is therefore a prerequisite for a complete periodontal diagnosis. However, radiographs are a valuable adjunct for the periodontal diagnosis and the diagnosis of trauma from occlusion. With standardized systems, radiographs may furnish additional quantitative data in clinical research.
The plaque‐inhibiting effect of copper amalgam
Authors: Hyyppä Tuula , Paunio Keuo 
Published: December 2005

Abstract In order to assess whether copper amalgam accumulates less bacterial plaque than silver amalgam, 14 copper amalgam cervical restorations were placed in 10 patients. Control silver amalgam fillings were placed in homologous teeth of the same jaw. To evaluate the amount of plaque, the stained areas on the amalgams were analyzed from photographs with a planimetric method. Further quantitative analyses of plaque growth on copper amalgam were carried out with microbiological methods, for which a new group of 10 patients was selected. Cervical cavities were prepared on both sides of the jaw. Specimens of copper amalgam and silver amalgam restorations were placed on opposite sides. The plaque was collected after 2 and 3 days and cultivated under aerobic and anaerobic conditions on blood agar plates and on Mitis Salivarius Agar. The results of both methods show a very significant inhibition of plaque growth on copper amalgam.These results were confirmed by scanning electron micrographs which showed that copper amalgam only had plaque on small areas. The plaque appeared in band formations arranged irregularly on the surface. Higher magnifications revealed a filamentous structure with predominating coccoid organisms. Scanning electron micrographs also showed that pellicle formation, which is considered to be necessary for bacterial adherence to the surface, took place on both amalgams.
Development of gingivitis in pre‐school children and young adults
Authors: Matsson Lars 
Published: December 2005

Abstract Earlier studies suggest that children and adults differ in the propensity to develop gingivitis when oral hygiene is abandoned. To confirm the existence of such a difference, a comparative study of pre‐school children and young adults was made with objective registration methods. The author performed all registrationsAfter a period of intensive oral hygiene, all cleaning of teeth was discontinued for 21 days. The amount of bacterial plaque, the amount of gingival exudate and crevicular leukocytes and the bleeding tendency were registered on days 0, 7, 14 and 21.During the experiment the amount of bacterial plaque increased continously in both groups. The amount of gingival exudate and the tendency to gingival bleeding increased to high values in the adults, while only a small rise was seen in the children. The amount of crevicular leukocytes increased in both groups, but the increment was greater in the adults.A comparison concerning differences in gingival exudate and bleeding tendency between pre‐school children and adults was undertaken for gingival units that showed a similar plaque development. Under these statistically acceptable prerequisites, it was shown that there is a real difference in the tendency to develop gingivitis between pre‐school children and adults.
Use of transformed data in clinical trials
Authors: Powell R. N. , Highfield J. E. , Murkell J. F. 
Published: December 2005

Abstract The conduct of clinical trials requires that satisfactory indices are available for the objective measurement of clinical signs and symptoms. While no ideal index exists, it is nevertheless possible to use existing indices, despite their ordinal nature, in such a manner that more sophisticated and complex null hypotheses may be tested. In particular the Analysis of Variance (ANOVA) permits significance tests of interactions between two or more variables.In the case of dental trials, tested differences between groups using one‐way statistical analyses imply that such differences arise from the effects of one variable only. If two variables are manipulated together, their effects are confounded.The capacity of ANOVA to attribute data variability to main effects and interactions is its great power. To enable plaque and gingival inflammation scores to be analysed in this manner it is suggested that a derived frequency score, the G‐ratio, should be employed. Where there are four possible scores (0,1,2,3), there are three possible G‐ratios – G(0), G(O,1) or G(0,2). The G‐ratio which gives an overall mean closest to 0.50 is chosen for any particular investigation in order to avoid skew data distribution.In order to meet ANOVA assumptions, the G‐ratio should be formed on groups of not less than 10 surfaces. Since the distribution of any measure based on a proportion is unlikely to be normal, the data should also be transformed so that X'= are sin x which is to say that the transformed score is equal to the angle whose sine is the square root of the raw score.A clinical study of the effects of lectures and individual instruction in oral hygiene was subjected to analysis by a five‐way ANOVA. Location and jaw effects were markedly qualified by interactions. Such considerations point to the need for care in the design of trials where subject variability, repeated measurements, trial manipulations and interactions occur.
Screening for periodontal disease
Authors: Sheiham Aubrey 
Published: December 2005

Abstract The prime objective of screening is to detect disease at an earlier stage than would normally occur with people presenting with the disease, on the assumption that earlier treatment would alter the natural history of the disease in a significant proportion. However, before a screening survey is done a number of conditions should be fulfilled. The disease should be an important health problem; there should be effective and acceptable treatments available for those with the disease; the natural history of the disease should be adequately understood and there should be an agreed policy on whom to treat.Periodontal disease does not fulfil many of the requirements for a disease suitable for population screening. There is no reliable evidence that earlier detection alters the natural history of the disease or the survival and function of the teeth. Neither is there sufficient information on the importance of clinical signs of periodontal disease. We do not know whether screening tests are able to detect periodontal diesease which is likely to have an important impact on periodontal health. For example, is bleeding an important sign of destructive periodontal disease? Does gingivitis evidenced as redness progress to alveolar bone destruction? The lack of answers to these questions casts serious doubts on the accuracy of estimates of periodontal treatment needs which include all persons with a positive gingivitis score as needing treatment.A number of other gaps in our knowledge relating to periodontal disease are outlined. Because of these, it was concluded that screening for periodontal disease is not justified at present. Instead, research should be directed at answering questions about the natural history of periodontal diseases, the effectiveness of prevention and treatment, the significance of clinical signs of periodontal disease and the validity, sensitivity and specificity of the signs.
General anaesthesia for periodontal surgery
Authors: Manson J. D. , Midlar‐Danks S. 
Published: December 2005

Abstract. A technique is described in which full‐mouth periodontal surgery is carried out under general anaesthesia. The use of an endotracheal tube with inflatable cuff allows good visibility and access to all parts of the mouth unhampered by a throat pack; access is further improved by sloping the operating table foot‐down.A system of haemorrhage control is used involving a combination of procedures: smooth anaesthetic induction and controlled carbon dioxide levels; intravenous injection of a fibrinolytic inhibitor (epsilon amino‐caproic acid); foot‐down tilt to the operating table and infiltration with local analgesic solution.The advantages and disadvantages of the technique are discussed.
Gingival inflammation and bone loss in periodontal disease
Authors: Kardacihi B. , Wolffe G. N. , Manson J. D. 
Published: December 2005

Abstract Fifty subjects between 27 and 43 years of age were studied to determine the relationship between the severity of gingival inflammation, the amount of bone loss and the plaque score in interproximal sites.The results indicate moderately good correlations between Gingival Index or Plaque Index and percentage bone loss. However a low correlation was found between the amount of crevicular fluid and percentage bone loss. Gingival Index and Plaque Index were well correlated. It was also found that when patients were divided into two age groups, younger and older than 35 years, the older individuals studied had more bone loss interproximally compared with the younger despite comparable amounts of plaque or gingival inflammation. The data suggest that both severity and longevity of the inflammation may play a role in determining the rate of alveolar bone resorption.
Histologic characteristics of experimental gingivitis in the juvenile and adult beagle dog
Authors: Matsson Lars , Attström Rolf 
Published: December 2005

Abstract An earlier study (Matsson & Attström 1979) revealed an unexplained difference between juvenile and adult dogs in the propensity to develop clinical signs of gingivitis. The aims of the present investigation were to depict the structural composition of clinically normal gingiva and to analyze the histologic changes in the gingiva during plaque development in juvenile and adult dogs.Six beagle dogs were used. Two periods of discontinued oral hygiene were studied, the first at 3 and the second at 12 months of age. Biopsies were sampled on days 0, 4, 7, 14, 21 and 28 of each period. Sections from the biopsies were analyzed at two levels of magnification.Compared to adult dog gingiva, juvenile gingiva seemed to display: 1) a thicker keratinized layer of the oral epithelium, 2) a junctional epithelium that structurally resembles the oral epithelium, 3) a cuticular structure at the surface of the junctional epithelium, 4) a limited mononuclear inflammatory cell response during experimental gingivitis, and 5) a delayed establishment of an infiltrated connective tissue portion during experimental gingivitis.In addition, during experimental gingivitis, subgingival plaque formed along the tooth surfaces to a lesser extent in the juvenile stage compared to adult dogs.
Development of experimental gingivitis in the juvenile and adult beagle dog
Authors: Matsson Lars , Attström Rolf 
Published: December 2005

Abstract. In a previous paper a lower tendency to develop gingivitis was reported among preschool children compared to adults. The aim of the present study was to clarify if the same age‐dependent difference exists in dogs.Six beagle dogs from the same litter were used. two periods of discontinued oral hygiene were studied, one period when the dogs were 3 months old and the other at 12 months. Prior to and between the experimental periods the animals were subjected to meticulous toothcleaning. During the experimental periods the Gingival and Plaque Index scores as well as the amounts of gingival exudate and crevicular leukocytes were determined on days 0, 4, 7, 14, 21 and 28.During the juvenile period the development of dental plaque was lower compared with the adult period. The frequency of gingival units with high Gingival Index scores was lower at every registration interval during the juvenile period. The amounts of gingival exudate and crevicular leukocytes increased to high values during the adult stage but only small increments were found in the juvenile stage. An intraindividual comparison of the increase in the amount of gingival exudate from day 0 to day 28 in areas with the same amount of dental plaque accumulation showed a lower increase in gingival exudate during the juvenile stage in all dogs.
Effects of a 1% chlorhexidine gel during the healing phase after inverse bevel mucogingival flap surgery
Authors: Bakaéen G. S. , Strahan J. D. 
Published: December 2005

Abstract A split‐mouth double‐blind trial was designed to compare the effects of chlorhexidine and placebo gels during the healing phase following mucogingival flap surgery.Fifteen patients were treated with 30 inverse bevel flap procedures, one on each side of the maxilla, with an interval of 4 weeks between each procedure. Gel was applied to the gums using a toothbrush once daily.Comparison of results revealed no significant differences in Plaque Index, Gingival Index, crevicular fluid or depth of pockets. More pain and swelling were recorded on the side treated with placebo gel, and more patients indicated that they preferred the chlorhexidine gel. The results were comparable to previous investigations using penicillin and suggest that, because of the reduced pain and swelling, chlorhexidine gel may be a suitable alternative to penicillin after periodontal flap surgery.
Cigarette smoking, oral hygiene and periodontal health in Swedish army conscripts
Authors: Preber Hans , Kant Theo , Bergström Jan 
Published: December 2005

Abstract Possible dissimilarities between smokers and nonsmokers regarding oral hygiene, gingivitis, periodontal pocketing and alveolar bone loss were studied in a sample of 134 army conscripts. Compared to nonsmokers, smokers had a higher plaque index and greater severity of gingivitis, while no differences were found concerning pocket depth and bone loss.It could be demonstrated that the difference regarding gingivitis disappeared when a check was made for plaque values. It still remains to be explained why plaque deposition is more pronounced in smokers.
Interproximal periodontal intrabony defects
Authors: Nielsen I. M. , Glavind L. , Karhing T. 
Published: December 2005

Abstract The purpose of the present investigation was to study the distribution of interproximal periodontal intrabony defects as related to age, sex and localization, and to examine the relationship between some possible etiological factors and the occurrence of intrabony defects.A total of 209 adult patients presenting for dental treatment at the Royal Dental College in Arhus participated in this study. The patients were subjected to a questionnaire and were examined clinically and radiographically. All osseous defects in the radiographs were recorded but only those with a depth and width of at least 2 mm were considered periodontal intrabony defects. Only 18 % of the participants had one or more periodontal intrabony defects but the prevalence was higher in older than in younger age groups. While periodontal intrabony defects occurred with the same frequency on the various tooth types, more defects were found on distal than on mesial surfaces. The presence of periodontal intrabony defects correlated with loss of attachment, increased tooth mobility, a wide interproximal space and open mesio‐distal contact relationships between the teeth.
Histometric evaluation of periodontal surgery II. Connective tissue attachment levels after four regenerative procedures
Authors: Caton Jack , Nyman Sture , Zander Helmut 
Published: December 2005

Abstract The present study was undertaken to determine the effect of four periodontal regenerative procedures on the connective tissue attachment level. The procedures tested were: 1) the modified Widman flap procedure, 2) the modified Widman flap procedure combined with transplantation of previously frozen autogenous red marrow and cancellous bone, 3) the modified Widman flap procedure in combination with implantation of beta tricalcium phosphate, and 4) periodic root planing and soft tissue curettage. Eight adult Rhesus monkeys, divided into four equal groups, were used. Periodontal pockets were produced around contralateral teeth in a standardized manner. In each group of animals, the pockets on one side of the jaws were subjected to one of the above‐mentioned surgical treatments, while the contralateral pockets remained as unoperated controls. Three weeks before surgery, a carefully designed plaque control program was instituted and continued until the animals were sacrificed 12 months after surgery. In histologic sections, linear measurements along the root surfaces were made from the cemento‐enamel junction (CEJ) to the most apical cells of the junctional epithelium (JE). These measurements from operated and unoperated sites were then compared.The data revealed that healing following the four different regenerative procedures resulted in the reformation of an epithelial lining (long junctional epithelium) along the treated root surfaces, with no new connective tissue attachment.