bluuebunny/crossref_metadata_2025_split huggingface dataset:
The dimensions of mandibular lingual tissues relative to the placement of a lingual bar major connector
Authors: Cameron Stephen M. , Torres Gloria T. , Lefler Thomas B. , Parker M. Harry 
Published: October 2010

Purpose The purpose of this investigation was to measure and describe the lingual tissues of the anterior mandible to determine the acceptable boundaries of the zone of nonmovable tissue for placement of a lingual bar and to compare these to existing numerical guidelines.Materials and Methods Eighty subjects, grouped by age and gender, with clinically normal mandibular lingual gingival tissues from second premolar to second premolar were examined. The lingual sulcular depths (AB) and the distance from the gingival crest to movable tissue of the floor of the mouth (AC) were recorded. The zone of lingual nonmovable tissue was calculated (AC − AB) for each tooth.Results For all subjects, the mean value of the probing depth (AB) ranged from 1.22 mm (±0.33 mm) for central incisors to 1.66 mm (±0.43 mm) for second premolars. The mean distance from the gingival crest to movable tissue of the floor of the mouth (AC) ranged from 7.44 mm (±1.59 mm) for central incisors to 10.28 mm (±2.55 mm) for second premolars. The mean height of the lingual nonmovable tissue (the zone available for the lingual bar; AC − AB) ranged from 6.22 mm (±1.59 mm) for central incisors to 8.63 mm (±2.57 mm) for second premolars. Most subjects presented with the minimum zone of nonmovable tissue at the central incisors, but with increasing age more subjects presented with minimum values at the posterior teeth. The multifactorial analysis of variance (ANOVA) for males' available nonmovable tissue shows significance for both tooth (p < 0.001) and age (p < 0.001) factors. The multifactorial ANOVA for females' available nonmovable tissue shows significance for both tooth (p < 0.001) and age (p < 0.001) factors. Of all subjects, 85% (88% of males, 83% of females) had 4 mm or more of nonmovable tissue, sufficient for a lingual bar. The amount of available room decreased in older females.Conclusion Within the limits of this study, the use of actual measurements of lingual tissues versus existing numerical guidelines increased the percentage of patients for which the lingual bar can be used from approximately 6% to approximately 85%.
Laboratory strength of glass ionomer cement, compomers, and resin composites
Authors: Piwowarczyk Andree , Ottl Peter , Lauer Hans‐Christoph , Büchler Alfred 
Published: October 2010

Purpose The study evaluates the compressive, flexural, and diametral tensile strengths of 8 core build‐up materials from different material classes (highly viscous glass ionomer cement, autocured resin composite, and compomers).Materials and Methods All materials were manipulated according to the manufacturers' recommendations for use as core materials. At a temperature of 23.0 ± 1.0°C the properties of compressive, diametral tensile and flexural strength were determined using a universal testing machine at 15 minutes, 1 hour, and 24 hours after material preparation. Using one‐way analysis of variance (ANOVA), multiple mean value comparisons were performed to determine significant differences (p≤.05) between the core restoration materials.Results The values for compressive strength varied from 40.3 ± 5.2 MPa (compomer) to 237.4 ± 37.3 MPa (autocured resin composite) for the 3 measurement times. At 15 minutes, 1 hour, and 24 hours after first mixing, the ANOVA showed significant differences (p≤.05) between the resin composite Core Paste and all of the other materials. Diametral tensile strengths ranged from 5.5 ± 1.1 MPa for glass ionomer cement to 39.1 ± 2.9 MPa for composite core material. Three‐point flexural strength showed values ranging from 12.1 ± 2.5 MPa for glass ionomer cement to 92.1 ± 9.7 MPa for compomer between the 3 measurement times.Conclusions Setting time influences the mechanical properties of the materials tested in this study. Autopolymerizing resin composite Core Paste demonstrated greater compressive and flexural strengths at the 3 measurement times than the other materials tested. Reinforced composites, in comparison to the autocured resin composites, yielded no improvement in tensile strength. Flexural and tensile strengths of the glass ionomer cement were lower than those of autocured resin composites and compomers.
Effects of carbamide peroxides on wear resistance and color change of enamel opposing porcelain
Authors: Clelland Nancy L , Dorosti Yassamin , Seghi Robert R. 
Published: October 2010

Purpose This study evaluated the effects of a simulated 1‐ and 2‐week night guard bleaching technique using various bleaching gel concentrations on wear resistance and color change of human enamel opposing a feldspathic porcelain substrate.Materials and Methods VMK 68 feldspathic porcelain was formed into 15‐mm disks (n = 63) and fired according to manufacturer's recommendations. Enamel cusps were formed and shaped from extracted third molars and treated with 1 of 3 bleaching materials for 7 or 14 days. Specimens were kept at 37°C in 100% humidity. The control group was subjected to identical conditions but with water replacing the bleaching gel between and during bleaching treatments. After simulated bleaching, the enamel cusp specimens were subjected to 3‐body wear testing opposite a highly polished porcelain substrate. Enamel wear was evaluated using optical scanning methods, and color was measured with a small‐aperture colorimeter. Data were subjected to a one‐way repeated‐ measure analysis of variance and various post hoc statistics.Results Results indicated that the within effect of treatment time (7 or 14 days) did not significantly affect (p= 0.13) the size of the resulting enamel wear facet, whereas the between effect of bleaching concentration was significant (p= 0.01). Statistical analysis of unbleached control groups suggests that between‐group differences can be explained by variations in wear rates of the 3 enamel groups, not by the concentration differences in bleaching gels. All bleaching treatments resulted in significant color changes (p= 0.04) compared to the unbleached control, but the bleach concentration did not significantly influence the magnitude of color change (p= 0.81).Conclusions A simulated night guard vital bleaching treatment of 1 or 2 weeks had no significant effect on the wear resistance of human enamel in vitro. The increased bleaching treatment time and concentration did not significantly affect the amount of enamel color change.
The effect of disinfectants on the properties of dental gypsum: 1. Mechanical properties
Authors: Abdelaziz Khalid M. , Combe Edward C. , Hodges James S. 
Published: October 2010

Purpose This study was conducted to evaluate the effect of selected disinfectants incorporated in the liquid of dental stones on material strength properties with the aim of developing a material with acceptable mechanical properties.Materials and Methods Two types of dental stone (types III and V) were mixed with aqueous solutions of 0.525% sodium hypochlorite, 0.1% and 10% povidone‐iodine, and 2% glutaraldehyde, and with water as a control. The liquid/powder ratios recommended by the manufacturer were used. These materials were subjected to further modification by adding a mixture of 1.0% gum arabic and 0.132% calcium hydroxide to the hemihydrate powders before mixing with the disinfectant solutions at 2 different liquid/powder ratios for each. Both the regular and the modified materials were tested for compressive and diametral tensile strength after 1 hour and 1 week from the start of the mix. The structure of set materials was determined by scanning electron microscopy examination of fracture surfaces.Results The disinfectants often reduced the strength of both types of dental stone. However, using either 0.1% povidone‐iodine or 0.525% sodium hypochlorite resulted in strength values comparable with that of the control. The addition of gum arabic and calcium hydroxide helped reduce the mixing liquid/powder ratios, improving the strength properties of the disinfected materials.Conclusions Chemical disinfectants reduce the strength of dental gypsum when used as mixing water substitutes. Gum arabic and calcium hydroxide additives permit a lower liquid/powder ratio and can help offset this weakening.
Survey of implant experience by prosthodontists in the United States
Authors: Eckert Steven E. , Koka Sreenivas , Wolfinger Glenn , Choi Yong‐Geun 
Published: October 2010

Purpose The paper presents results of a survey of members of the American College of Prosthodontists (ACP) conducted to determine experiences and practices with dental implants.Materials and Methods Preliminary survey questions regarding the prosthetic and surgical use of dental implants were developed. The master list of questions was distributed to communities of interest to establish the most pertinent items of interest. The final questionnaire was distributed to all members of the ACP living or practicing in the United States and members engaged in the U.S. armed services. Responses were compiled and analyzed to determine correlation of responses using the chi‐squared test for count data (level of significance α= 0.05). Fisher's exact test was applied to all significant responses.Results Surveys were distributed to 1815 ACP members. A total of 554 (31%) surveys were completed. On the basis of age distribution of survey respondents, it was determined that the respondents were representative of the ACP membership. The majority of the respondents (82%; CI, 79% to 85%) treat patients with implant‐supported prostheses, while 12% (CI, 10% to 15%) surgically place implants. Of those not placing implants, 24% reported a desire to place implants, while 43% of all respondents expressed a desire for an ACP‐sponsored course in implant placement. Increased age of the prosthodontist correlated negatively with a desire to place implants (p < 0.0001). Dissatisfaction with implant placement by others correlates with willingness to surgically place implants (p < 0.0001).Conclusions Most prosthodontists (82%) use implant‐supported prostheses in their practices, but most of the implants are placed by non‐prosthodontists. There is general satisfaction with implant placement regardless of the specialty of the practitioner placing the implants. Younger prosthodontists expressed a greater desire to surgically place implants but were not statistically more likely to do so.
Pressure generated on a simulated oral analog by impression materials in custom trays of different designs
Authors: Masri Radi , Driscoll Carl F. , Burkhardt John , von Fraunhofer Anthony , Romberg Elaine 
Published: October 2010

Purpose To measure the pressure exerted by maxillary edentulous impressions composed of 3 commonly used impression materials using four different impression tray configurations.Materials and Methods The study was performed using an oral analog that simulated an edentulous maxillary arch. Three pressure transducers were imbedded in the oral analog, 1 in the mid‐palate area and the other 2 in the right and left ridge (maxillary first premolar areas). Custom trays of 4 different configurations were fabricated. The 3 impression materials tested were irreversible hydrocolloid, light‐body and medium‐body vinyl polysiloxane, and polysulfide. A total of 128 impressions were made. The custom tray and the oral analog were mounted using a reline jig. A Satec universal testing machine was used to apply a constant pressure of 2 kg/cm2 over a period of 5 minutes on the loaded custom tray. The pressure was recorded every 10 seconds. Factorial analysis of variance and Tukey's multiple comparison test were used to analyze the results.Results A significant difference in the pressure produced using different impression materials was found (p≤0.001). Irreversible hydrocolloid and medium‐body vinyl polysiloxane produced a significantly higher pressure than light‐body vinyl polysiloxane and polysulfide impression materials. The presence of holes and/or relief did not significantly alter the magnitude of pressure.Conclusions All impression materials produced pressure during maxillary edentulous impression making. Tray modification was not important in changing the amount of pressure produced. The impression materials used had more effect on the pressure produced during impression making on the simulated oral analog.
Evaluation of the pH of a new carbonated soft drink beverage: An in vivo investigation
Authors: Bartlett David W. , Bureau George P. , Anggiansah Angela 
Published: October 2010

Purpose Recently, a modified version of a successful soft drink has been developed that aims to reduce the potential for dental erosion in consumers. The aim of this investigation was to compare the effect of the modified and original formula soft drink on the pH at various tooth surfaces during and after ingestion in subjects without erosion.Materials and Methods Fifteen subjects (10 female and 5 male) without dental erosion drank both a modified and an unmodified beverage for over 5 minutes in a randomized order. Oral pH was measured with antimony electrodes positioned on the labial and palatal surfaces of an incisor and premolar and held in place by a close‐fitting vacuum‐formed appliance. The results were compared (using the Wilcoxon signed rank test, with matched pairs) for the percentage and total time that pH fell below 4, 5, and 5.5.Results The percentage and total time that pH fell below 4 was significantly different between the drinks (P <0.02), but the total time that pH fell below 5 and 5.5 was not. The time taken for subjects to return to pre‐exposure pH levels in the mouth showed considerable variation between individuals.Conclusions The modified‐formula drink appeared to have less erosive potential than the original formula when assessed by measuring pH at the tooth surface. Although the erosive potential has been reduced by modifying the soft drink, it has not been eliminated.
Understanding Our Understanding of Strategic Scenarios: What Role Do Chunks Play?
Authors: Linhares Alexandre , Brum Paulo 
Published: October 2010

AbstractThere is a crucial debate concerning the nature of chess chunks: One current possibility states that chunks are built by encoding particular combinations of pieces‐on‐squares (POSs), and that chunks are formed mostly by “close” pieces (in a “Euclidean” sense). A complementary hypothesis is that chunks are encoded by abstract, semantic information. This article extends recent experiments and shows that chess players are able to perceive strong similarity between very different positions if the pieces retain the same abstract roles in both of them. This casts doubt on the idea that POS information is the key information encoded in chess chunks, and this article proposes, instead, that the key encoding involves the abstract roles that pieces (and sets of pieces) play—a theoretical standpoint in line with the research program in semantics that places analogy at the core of cognition.
Extending the E‐Z Reader Model of Eye Movement Control to Chinese Readers
Authors: Rayner Keith , Li Xingshan , Pollatsek Alexander 
Published: October 2010

AbstractChinese readers' eye movements were simulated in the context of the E‐Z Reader model, which was developed to account for the eye movements of readers of English. Despite obvious differences between English and Chinese, the model did a fairly good job of simulating the eye movements of Chinese readers. The successful simulation suggests that the control of eye movements in reading Chinese is similar to that in an alphabetic language such as English.
Language Evolution by Iterated Learning With Bayesian Agents
Authors: Griffiths Thomas L. , Kalish Michael L. 
Published: October 2010

AbstractLanguages are transmitted from person to person and generation to generation via a process of iterated learning: people learn a language from other people who once learned that language themselves. We analyze the consequences of iterated learning for learning algorithms based on the principles of Bayesian inference, assuming that learners compute a posterior distribution over languages by combining a prior (representing their inductive biases) with the evidence provided by linguistic data. We show that when learners sample languages from this posterior distribution, iterated learning converges to a distribution over languages that is determined entirely by the prior. Under these conditions, iterated learning is a form of Gibbs sampling, a widely‐used Markov chain Monte Carlo algorithm. The consequences of iterated learning are more complicated when learners choose the language with maximum posterior probability, being affected by both the prior of the learners and the amount of information transmitted between generations. We show that in this case, iterated learning corresponds to another statistical inference algorithm, a variant of the expectation‐maximization (EM) algorithm. These results clarify the role of iterated learning in explanations of linguistic universals and provide a formal connection between constraints on language acquisition and the languages that come to be spoken, suggesting that information transmitted via iterated learning will ultimately come to mirror the minds of the learners.
What Makes People Revise Their Beliefs Following Contradictory Anecdotal Evidence?: The Role of Systemic Variability and Direct Experience
Authors: Markovits Henry , Schmeltzer Christophe 
Published: October 2010

AbstractThe extent to which belief revision is affected by systematic variability and direct experience of a conditional (if A then B) relation was examined in two studies. The first used a computer generated apparatus. This presented two rows of 5 objects. Pressing one of the top objects resulted in one of the bottom objects being lit up. The 139 adult participants were given one of two levels of experience (5 or 15 trials) and one of two types of apparatus. One of these was completely uniform, while the other had an element that randomly alternated in its result. Following the testing of the apparatus, participants were asked to rate their certainty of the action of the middle element, which was always uniform (the AB belief). Then they were told of an observation inconsistent with this belief. Participants were then asked whether they considered the AB belief or the anecdotal observation to be more believable. Results showed that increased experience decreased the tendency to reject the AB belief, when the apparatus did not have any randomness. However, the presence of a single element showing random variation in the system strongly increased rejection of this belief. A second study looked at the effect of a single random element on a mechanical system as well as an electronic system using graphical representations. This confirmed the generality of the effect of randomness on belief revision, and provided support for the effects of embedding a belief into a system of relations. These results provide some insight into the complex factors that determine belief revision.
Spatial Visualization in Physics Problem Solving
Authors: Kozhevnikov Maria , Motes Michael A. , Hegarty Mary 
Published: October 2010

AbstractThree studies were conducted to examine the relation of spatial visualization to solving kinematics problems that involved either predicting the two‐dimensional motion of an object, translating from one frame of reference to another, or interpreting kinematics graphs. In Study 1, 60 physics‐naíve students were administered kinematics problems and spatial visualization ability tests. In Study 2, 17 (8 high‐ and 9 low‐spatial ability) additional students completed think‐aloud protocols while they solved the kinematics problems. In Study 3, the eye movements of fifteen (9 high‐ and 6 low‐spatial ability) students were recorded while the students solved kinematics problems. In contrast to high‐spatial students, most low‐spatial students did not combine two motion vectors, were unable to switch frames of reference, and tended to interpret graphs literally. The results of the study suggest an important relationship between spatial visualization ability and solving kinematics problems with multiple spatial parameters.
Assessment of a novel device‐based diagnostic algorithm to monitor patient status in moderate‐to‐severe heart failure: rationale and design of the CLEPSYDRA study
Authors: Auricchio Angelo , Brugada Josep , Ellenbogen Kenneth A. , Gold Michael R. , Leyva Francisco ,   for the CLEPSYDRA investigators
Published: October 2010

AimsMonitoring systems integrated into electronic implantable devices for heart failure (HF) have significantly expanded the possibility of obtaining diagnostic information and can be used to enhance patient follow‐up. The ability to obtain advance warning of worsening HF is currently being explored using a variety of diagnostic parameters. A novel device‐based algorithm, physiological diagnostic (PhD), combines data from minute ventilation and accelerometer sensors to provide an indicator of the overall status of HF patients and detect clinically relevant acute HF events. The objective of this study was to evaluate the effectiveness of the PhD algorithm for detecting HF events in patients with HF.MethodsCLEPSYDRA is a multicentre, prospective, non‐randomized, single‐arm double‐blinded study in 62 centres in Europe, the USA, and Canada. Patients with moderate‐to‐severe HF, on stable optimal pharmacological therapy, QRS ≥ 120 ms, and ejection fraction ≤0.35% will be included. Patients will be followed at 3‐month intervals until study end, or for a minimum of 13 months. The primary endpoint is the sensitivity of the PhD (proportion of HF‐related clinical events occurring within a 4‐week period after a PhD HF indication). Secondary endpoints include the sensitivity of PhD with regard to HF events related to oral treatment modification, and adverse events. The first patient was included in October 2009. At the time of manuscript submission (Week 26, 2010), 214 patients had been enrolled. Study results are expected in 2012.PerspectiveCLEPSYDRA will provide essential data on the utility of the PhD algorithm in a HF population with blinded investigators and patients. A successful outcome will demonstrate the potential for the algorithm to be implemented in clinical practice. This would improve clinical management and further the ability to generate dynamic and reliable risk profiles for patients with HF.