ABSTRACT
OBJECTIVE: To evaluate the influence of dietary simulating solvents on surface hardness of chemical, light and dual-cure provisional restorative materials. METHODS: The provisional materials evaluated were Temporary Bridge Resin (TBR) (Dentsply), Protemp Garant (PG) (ESPE-3M), Luxatemp Automix (LA) (DMG), Unifast LC (UF) (GC), Luxatemp Solar Plus (LS) (DMG) and Provipoint DC (PP) (Vivadent). Materials were manipulated according to manufacturers' instructions and placed in customized molds. Immediately after setting/light-polymerization, the materials were stored in the following dietary simulating solvents at 37 degrees C for 1 week: (a) heptane, (b) 100% ethanol solution (ES), (c) 75% ES, (d) 50% ES, (e) 25% ES, and (f) distilled water. Specimens stored in air were used as control. After the one-week conditioning period, hardness testing (KHN; n = 6) was carried out with a digital microhardness tester (load=100 gf; dwell time=15 s). Hardness ratios were plotted against the solubility parameter of the solvents and the Environmental Index was subsequently computed. Data were subjected to ANOVA/Scheffe's test at significance level 0.05. RESULTS: For all materials, conditioning in the various ES resulted in significantly lower KHN values compared to conditioning in air and water. TBR, UF and PP were also significantly softened by conditioning in heptane. Ranking of Environmental Index was as follows: LS>LA>PG>TBR>UF>PP. SIGNIFICANCE: All provisional materials were significantly softened by aqueous ethanol solutions. Materials based on bis-acryl resins were generally more resistant to damage from dietary solvents.
Subject(s)
Dental Restoration, Temporary , Denture, Partial, Temporary , Diet , Solvents , Composite Resins , Ethanol , Hardness , Heptanes , Methacrylates , Methylmethacrylates , Polyurethanes , Solubility , WaterABSTRACT
Six boys aged 9 to 12 years attended a tutoring class focusing on reading for 30 minutes each morning. The investigators employed a modified Latin-square design in which each child began with a 5-day baseline phase followed by six 10-day treatment phases that used drug placebo, noncontingent reinforcers, 0.3 mg/kg methylphenidate, 0.7 mg/kg methylphenidate, and self-reinforcement in various combinations. Amount of academic performance was the major measure of outcome and the target behavior of self-reinforcement. Drug placebo and noncontingent reinforcers had no systematic impact. Methylphenidate had differential effects across the recorded behaviors. Self-reinforcement improved the target behavior; the mean effect size for self-reinforcement was 2.66. The combined effects of methylphenidate and self-reinforcement on academic performance were greater than either of the treatments given alone (mean effect size = 2.89).
Subject(s)
Attention Deficit Disorder with Hyperactivity/therapy , Behavior Therapy , Methylphenidate/therapeutic use , Motivation , Attention Deficit Disorder with Hyperactivity/psychology , Child , Combined Modality Therapy , Dose-Response Relationship, Drug , Humans , Male , Reinforcement Schedule , Remedial Teaching , Social Behavior , Treatment OutcomeABSTRACT
We evaluated the effects of reciprocal peer tutoring combined with group reinforcement contingencies on the arithmetic performance of 12 underachieving fifth-grade students. Results indicated that the intervention increased the students' arithmetic performance to a level indistinguishable from their classmates during treatment and 12-week follow-up phases. Pre-, post-, and follow-up sociometric data indicated that the students who participated in the treatment groups increased their amount of peer affiliation with other treatment group members.
Subject(s)
Behavior Therapy/methods , Learning Disabilities/therapy , Peer Group , Remedial Teaching/methods , Child , Cooperative Behavior , Female , Humans , Learning Disabilities/psychology , Male , Mathematics , Social Environment , Token Economy , UnderachievementABSTRACT
The effects of methylphenidate and behavioral self-control training on sustained attention were compared in 12 boys aged 6-9 years. Subjects were of low-average intelligence and had academic and behavioral problems including distractibility, short attention span, and impulsiveness. Treatment conditions (baseline, placebo, methylphenidate, and behavioral self-control training) were assigned according to a single-subject randomized blocks design. Attention was measured by the Children's Checking Test (CCT). Methylphenidate improved performance on the CCT and was superior to the other treatment conditions. Several children benefited from behavioral training, but statistical analysis of this change was nonsignificant. These results are consistent with and extend those of previous studies.
Subject(s)
Attention Deficit Disorder with Hyperactivity/therapy , Attention/drug effects , Behavior Therapy/methods , Methylphenidate/therapeutic use , Attention Deficit Disorder with Hyperactivity/drug therapy , Child , Humans , Individuality , Intelligence , MaleABSTRACT
Ten, black, second-grade boys served in a series of single-subject studies. They were from poor families, did not do well in arithmetic, were deficient in sustained attention, and presented behavior problems at school. One boy was a therapeutic confederate. Of the remaining nine nontreated students, three observed the confederate reinforced by a teacher, three observed the confederate self-reinforce without having an opportunity to use "self-reinforcement" themselves, and three observed self-reinforcement while having an opportunity to use "self-reinforcement." The target behavior was attending. Other measures of outcome were glancing, academic achievement, and accuracy of reinforcement. The basic experimental design consisted of an ABAB withdrawal applied to the confederate while the nontreated students remained on baseline. Generalization was expressed as a ratio (i.e., percent change in the generalization measure divided by percent change in the target behavior). Teacher-administered reinforcers to the confederate did not produce generalization of any kind. Both arrangements of self-administered reinforcers to the confederate produced across-subjects generalization and subject-response generalization. Additionally, the confederate manifested response generalization.
Subject(s)
Attention , Child Behavior Disorders/rehabilitation , Generalization, Psychological , Learning Disabilities/rehabilitation , Token Economy , Child , Child Behavior Disorders/psychology , Humans , Learning Disabilities/psychology , Male , Outcome and Process Assessment, Health Care , Socioeconomic FactorsSubject(s)
Behavior Therapy/methods , Child Behavior Disorders/rehabilitation , Underachievement , Child , Female , Humans , Token EconomyABSTRACT
Eight fifth- and sixth-grade black males engaged in a set of single-subject, multiple-baseline studies to determine the relative effects of self-observation and self-reinforcement. A black male college student employed the children as research assistants who would study their own behavior. The employer negotiated a series of individualized contracts with each boy. The contracts specified what self-regulation procedures the subject would perform. Overall, the children were more consistent in carrying out their contracts when they were on self-reinforcement than when they were on self-observation. Second, the children were more effective in increasing behavioral deficits than they were in decreasing excesses. Third, self-reinforcement was clearly a superior means of improving their own behavior than was self-observation.
