Self-Distancing as a Strategy to Regulate Affect and Aggressive Behavior in Athletes: An Experimental Approach to Explore Emotion Regulation in the Laboratory.

Self-regulation, especially the regulation of emotion, is an important component of athletic performance. In our study, we tested the effect of a self-distancing strategy on athletes' performance in an aggression-inducing experimental task in the laboratory. To this end, we modified an established paradigm of interpersonal provocation [Taylor Aggression Paradigm (TAP)], which has the potential to complement field studies in order to increase our understanding of effective emotion regulation of athletes in critical situations in competitions. In our experimental setting, we first tested the applicability of the self-distancing perspective and the athletes' ability to dynamically adapt besides the self-distanced perspective a self-immersed perspective to provocation in the TAP. Secondly, we investigated how this altered perspective modulated regulatory abilities of negative affectivity, anger, and aggression. The experiment consisted of two conditions in which the participant adopted either a self-immersed or a self-distanced perspective. Forty athletes (female: 23; male: 17) from different team (n = 27) and individual sports (n = 13) with a mean age of 23.83 years (SD = 3.41) competed individually in a reaction-time task against a (fictitious) opponent. Results show that athletes are equally able to adopt both perspectives. In addition, within-person analyses indicate that self-distancing decreased aggressive behavior and negative affect compared to the self-immersed perspective. Our results suggest that self-distancing modulates different levels of athletes' experience (i.e., affect and anger) and behavior. Furthermore, this demonstrates the feasibility of testing self-regulation of emotion in athletes in a laboratory setting and allows for further application in research in sports and exercise psychology.

Histological, morphological, profilometric and optical changes of human tooth enamel after microabrasion.

PURPOSE: To determine the loss of enamel after a single 20-secondsapplication of a microabrasion slurry and to evaluate structural changes by means of laser fluorescence, and microscopic and optical measurements. METHODS: Defined buccal areas with a diameter of 2 mm from 16 extracted human molars were demineralized for 12 weeks using a demineralization gel (pH 4.8). The created artificial white-spot lesions were divided corono-apically in control and test sites, using a rubber cement that prospectively covered the untreated control site. Teeth were divided into two groups of eight teeth each. One group was treated with an abrasive cleaning paste (Pell-ex) and the other group with a commercially available microabrasion slurry (Opalustre) for 20 seconds, applying a load of 200 g. Before and after treatment, standardized photographs were taken for the determination of luminescence and profilometric tracings of the surface, and these were recorded for the determination of enamel loss. The grade of demineralization was quantified using a laser fluorescence method (Diagnodent). Statistical differences were checked using a Mann Whitney and student t-test. Replicas of the treated areas were made for scanning electron microscopy (SEM) analysis, and teeth were histologically investigated by polarized light microscopy. RESULTS: Loss of tooth substance was significantly higher (P < or = 0.001) for the microabrasion group (134.8 +/- 35.5 microm) compared with the abrasive cleaning paste group (4.5 +/- 1.2 microm). After treatment, statistically significant differences in fluorescence and luminescence measurements could only be detected for microabraded teeth. No significant changes were noted for teeth treated with an abrasive cleaning paste. Histological findings confirmed removal of the demineralized surface zone when microabrading the enamel, whereas no changes were observed in the test group treated with an abrasive cleaning paste. Polarized light microscopy did not indicate any changes in the mineralization pattern, for example compaction, in the treated subsurface zone.

Potential of restorative systems with simplified adhesives: quantitative analysis of wear and marginal adaptation in vitro.

PURPOSE: This in vitro study evaluated: (1) marginal adaptation and (2) attritional wear of composite resin materials with simplified bonding systems. METHODS: 36 standardized Class II MOD cavities were prepared in human mandibulary first molars and divided randomly in six equal groups. Restorations were placed with combinations of resin composites and simplified bonding systems: A = Arabesk and Solobond, B = Z 100 and Scotchbond 1, C = Prodigy and OptiBond, D = FHC Merz light and Resulcin Aqua Prime/Monobond as well as E = Sculpt-It and Bond 1. F = Amelogen Universal in combination with the classical 3 part adhesive system Permaquick served as control for marginal adaptation. For wear rates, enamel versus human enamel served as control. All specimens were subjected to long-term thermomechanical stress in a computer-controlled masticator. Human enamel cusps served as antagonists. Marginal adaptation was evaluated by SEM quantitatively before and after stress. Attritional wear in occlusal contact areas was measured on specimens and antagonists with a surface analyzer. Results were tested for statistical significance with ANOVA. RESULTS: SEM marginal analysis exhibited variations from 45.1 +/- 19.9% (D) to 7.9 +/- 5.4% (E) continuous margin after thermomechanical loading in test groups. All groups achieved statistically significant lower scores (P < 0.05) for marginal adaptation than the control (F: 87.4 +/- 15.5%). Total attritional wear (specimen + antagonist) varied from 153.2 +/- 32.3 microm (D) to 272.3 +/- 132.7 microm (A). Wear of A and F was statistically significantly higher (P < 0.05) than enamel versus enamel (162.2 +/- 111.2 microm).

Linear displacement and force induced by polymerization shrinkage of resin-based restorative materials.

PURPOSE: To measure the linear displacement and force induced by polymerization shrinkage of a series of resin-based restorative materials. METHODS: The materials tested were 10 ultrafine midway-filled resin-based composites, mainly used in anterior restorations (Brilliant Dentin, Brilliant Enamel, Charisma F, Pertac II Aplitip, Prodigy, Resulcin, Sculpt-it, Synergy Duo, Tetric and Z100), 11 ultrafine compact-filled composites, suggested by the manufacturers as "amalgam substitutes" for posterior restorations (Alert, Ariston pHc, Definite, EXI-119, EXI-120, Nulite F, Prodigy Condensed, Prodigy High Viscosity, Solotaire, Surefil and Synergy Compact), and six polyacid-modified composites (Compoglass, Dyract, Dyract AP, Elan, F2000 and Hytac Aplitip), also known as compomers. Each property was measured for 180 seconds from the start of curing with the help of custom made devices in eight specimens for each material. Statistical evaluation of the data was performed with one-way ANOVA, Tukey's Studentized Range (HSD) Test (P= 0.05) and simple linear regression. RESULTS: Statistically significant differences among groups and among composites were found for both of the properties that were studied. The ultrafine compact-filled composites (amalgam substitutes) exhibited the least linear displacement, followed by the polyacid-modified composites (compomers) and the ultrafine midway-filled composites, with statistically significant differences among all groups. The groups followed the same order in the polymerization force, with only the compomer-amalgam substitute comparison not being statistically significantly different. The simple linear regression showed that the two studied properties were also highly correlated (r=0.89).

Evaluation of published clinical studies for reproducibility, comparability and adherence to evidence-based methods.

PURPOSE: To evaluate the "Materials and Methods" of long-term clinical studies in relation to documentation, reproducibility and comparability with and without employing the systematic methods of evidence-based medicine. MATERIALS AND METHODS: The "Materials and Methods" sections in 45 clinical long-term published studies of direct posterior resin-based composite restorations were evaluated for their use of systematic methods of evidence-based medicine. The search was limited to the years 1988-1997, using the key words "clinical study/evaluation/results/report, long-term, in vivo, posterior, Class I/II, composite, restoration". Special attention was directed to comparisons of the underlying documentation, descriptions of the operative techniques used, and their reproducibility. In addition, an evidence-based search was carried out using the Internet PubMed interface for MEDLINE, using identical synonyms, to identify studies with high levels of quality of evidence. Documentation, reproducibility, and comparability of "Materials and Methods" were also evaluated. RESULTS: Results revealed how difficult it is to interpret results based on tenuous premises, subjective standards, and inadequate study designs. Only one article could be identified when the search was limited to "humans" and "randomized clinical trials". None of the articles, even when fulfilling the highest quality of evidence, showed sufficient or satisfactory quality of reproducibility in their descriptions in Materials and Methods.

Two-year clinical and SEM evaluation of glass-fiber-reinforced inlay fixed partial dentures.

PURPOSE: To clinically evaluate conservative fiber-reinforced composite inlay fixed partial dentures (IFPDs) bonded to inlay abutments. MATERIALS AND METHODS: Forty fiber-reinforced composite IFPDs were made for 29 patients. Restorations were manufactured with the composite Targis reinforced by Vectris prefabricated glass-fiber elements and were inserted with a high viscosity insertion technique. Forty bonded IFPDs were examined clinically after 1 year, and 25 after 2 years, using modified USPHS criteria. Twenty-five abutment inlays and 12 pontics were analyzed quantitatively by scanning electron microscopy SEM. Results were tested for statistical significance with ANOVA. RESULTS: Although most clinical criteria were rated "alpha", four IFPDs had to be replaced: two retainers debonded and two presented total delamination of veneering material from fiber framework. Two partial delaminations were repaired intraorally. No fractures of framework were observed. SEM marginal analysis of tooth-composite interface exhibited 96.5 +/- 3.0% continuous margin at baseline, 91.0 +/- 5.7% at the 1-year and 89.6 +/- 5.2% at the 2-year recall. Decrease of marginal quality was statistically significant between baseline and 1 year (P= 0.001), but not between 1- and 2-year recalls.

Advances in abrasive technology--prophylaxis pastes.

A newly developed prophylaxis paste that contains perlite as an abrasive medium was compared to conventional prophylaxis pastes with regard to relative dentin and enamel abrasion, cleaning ability, and polishing power. Rubber cups and nylon brushes were used as paste carriers. Water, flour of pumice, and a dentin polishing paste served as controls. The Prophylaxis Paste Index was created to assess the clinical potential of the various prophylaxis pastes more accurately. The index was computed for dentin as cleaning ability divided by relative dentin abrasion x surface roughness (in Ra) x 10, and for enamel as cleaning ability divided by relative enamel abrasion x surface abrasion (in Ra). On dentin and enamel, the perlite-based prophylaxis paste consistently yielded low relative dentin and enamel abrasion values, a good cleaning ability, and low surface roughness scores with both rubber cups and nylon brushes. Of all tested prophylaxis pastes, the perlite-based prophylaxis paste excelled in the Prophylaxis Paste Index on dentin and enamel and with both rubber cup and nylon brush applications. Therefore, a perlite-containing prophylaxis paste may have broad professional therapeutic indications and may be used universally as a single paste to clean and polish both dentin and enamel.

Cleaning and polishing efficacy of abrasive-bristle brushes and a prophylaxis paste on resin composite material in vitro.

OBJECTIVE: This study evaluated the cleaning and polishing effect of a prophylaxis paste (Cleanic), two differently shaped abrasive-bristle brushes (Occlubrush normal cup and Occlubrush minipoint), and a nylon-bristle brush (Prophy brush) on a fine (Tetric Ceram) and a coarse hybrid resin composite (Tetric Condense) under standardized conditions. METHOD AND MATERIALS: A total of 48 round specimens with a diameter of 17.2 mm (232.32 mm2) of a fine and a coarse hybrid resin composite were readied and fixed on scanning electron microscopic mounts. After a standardized polishing procedure, the mean surface roughness values were evaluated using five horizontal and five vertical measurements over an area of 1 x 3 mm. The gloss of each specimen was assessed with a spectrophotometer. Both hybrid resin composite groups were treated with one of the following instruments: a nylon-bristle brush (n = 8), a normal-cup abrasive-bristle brush, or a minipoint abrasive-bristle brush. The medium used was either water (control) or a prophylaxis paste. Surface roughness and gloss were measured after instrumentation times of 15, 30, 60, 90, and 120 seconds. For the evaluation of cleaning ability, another 48 total round specimens of fine and coarse hybrid resin composite were covered with a thin layer of black dispersion color and air dried for 24 hours. Specimens were treated with a nylon-bristle brush or an abrasive-bristle brush in combination with water or prophylaxis paste for 15, 30, 60, 90, and 120 seconds. At the beginning and after every treatment interval, the specimens were scanned, the images were digitized, and the percentage of cleaned surface was measured planimetrically. RESULTS: The abrasive-bristle brush, used in combination with water, produced the best outcomes for cleaning ability, surface roughness, and gloss on resin composite restorations. CONCLUSION: There is no positive cumulative effect when an abrasive-bristle brush, with its cleaning and polishing effect, is used in conjunction with a prophylaxis paste. Abrasive-bristle brushes used with plain water are highly suitable for cleaning and polishing resin composite surfaces.