In vitro evaluation of the effect of natural orange juices on dentin morphology

The patient's diet has been considered an important etiological factor of dentin hypersensitivity. The frequent ingestion of acidic substances can promote the loss of dental structure or remove the smear layer. The purpose of this study was to evaluate the degree of smear layer removal and dentinal tubules exposure by different natural orange juices. Extracted human teeth were submitted to manual scaling in order to develop the smear layer. Seventy dentin samples were obtained and distributed into the following groups: Control, lime orange, lime, valência orange, navel orange, mandarin, and tangerine. Each group included 2 methods of application: Topical and topical + friction. After preparation for SEM analysis, photomicrographs were assessed by a blind calibrated examiner using an index system. The Kruskal-Wallis test indicated a significant influence of the orange juices on smear layer removal. Significant difference was observed between navel orange, valência orange, mandarin and the control group (p < 0.05). These orange juices resulted in greater removal of the smear layer and greater opening of dentinal tubules. The comparison between the application methods for each group using the Mann-Whitney test showed that friction increased smear layer removal significantly only for lime orange and lime. The data suggest that certain natural orange juices are more effective in terms of smear layer removal and dentinal tubules exposure than others.

Meta-heuristic approaches for a soft drink industry problem

The present paper evaluates meta-heuristic approaches to solve a soft drink industry problem. This problem is motivated by a real situation found in soft drink companies, where the lot sizing and scheduling of raw materials in tanks and products in lines must be simultaneously determined. Tabu search, threshold accepting and genetic algorithms are used as procedures to solve the problem at hand. The methods are evaluated with a set of instance already available for this problem. This paper also proposes a new set of complex instances. The computational results comparing these approaches are reported. © 2008 IEEE.

Evaluating genetic algorithms with different population structures on a lot sizing and scheduling problem

This paper studies the use of different population structures in a Genetic Algorithm (GA) applied to lot sizing and scheduling problems. The population approaches are divided into two types: single-population and multi-population. The first type has a non-structured single population. The multi-population type presents non-structured and structured populations organized in binary and ternary trees. Each population approach is tested on lot sizing and scheduling problems found in soft drink companies. These problems have two interdependent levels with decisions concerning raw material storage and soft drink bottling. The challenge is to simultaneously determine the lot sizing and scheduling of raw materials in tanks and products in lines. Computational results are reported allowing determining the better population structure for the set of problem instances evaluated. Copyright 2008 ACM.

Utilização do alcohol use disorders identification test (Audit) para identificação do consumo de álcool entre estudantes do ensino médio

Alcohol is one of the drugs most widely used among teenagers. Just recently, studies have been developed regarding the screening of use of alcohol by this population. This work aimed to investigate the use of AUDIT as a method for screening and evaluation of alcohol consumption among High School students. The sample was composed by 1227 students from two public schools, who answered to the Alcohol Use Disorders Identification Test (AUDIT) and informed their socioeconomic level, religion, and occurrence of relationship problems caused by drunkenness of family members. Using an 8 cut-off point, AUDIT has identified 17.8% of students with risk drinking. These results have revealed that AUDIT is easy to be applied and well accepted by the students. It was also evident the importance of this instrument in the follow-up programs of prevention and intervention of alcoholic beverages use.

Características reológicas e sensoriais de bebidas lácteas funcionais

This research studied the effects of the independent variables whey protein concentrate - WPC (3.0; 3.5; 4.0%), skimmed milk powder - SMP (4.0; 5.0; 6.0%), and isolated soy protein - IPS (1.5; 2.0; 2.5%) on the rheological and sensorial characteristics of functional dairy beverages. In all tests 7% of sucrose was added to the ingredients. The rheological parameters were obtained in duplicate at the temperature of 10° C using a cone and plate rheometer, and fitted to the Power law model. The samples revealed a non-Newtonian fluid behavior both in the upward and downward curves, typical of a tixotropic fluid. The dairy beverages were submitted to a sensory analysis by a group of fifty untrained tasters who used a hedonic scale of nine points, the extremes being 1 - disliked extremely and 9 - liked extremely, in order to evaluate the following parameters: general acceptability; appearance and color; consistency; taste and aroma. The dairy beverage produced with 3% WPC, 6% SMP and 1.5% IPS, (treatment 3), was the one that obtained the best average score for those attributes and was preferred by the tasters. The variables SMP and IPS and the interaction between WPC and SMP presented a positive effect on the sensory consistency attributes: the higher amount of those ingredients in the formula the more the tasters liked the consistency.

In vitro evaluation of the effect of dietary acids and toothbrushing on human root dentin permeability

OBJECTIVES: The purpose of this in vitro study was to quantify the alterations in human root dentin permeability after exposure to dietary acids and to evaluate the effect of toothbrushing after acid application. METHOD AND MATERIALS: Extracted human third molars had their crowns sectioned above the CEJ, pulp tissue removed, and cervical root dentin exposed using a high-speed bur (approximately 1 mm in depth of substance loss). From each root fragment, one specimen was prepared. A total of 25 specimens were used and distributed randomly into five groups. The specimens were attached to a hydraulic pressure apparatus to evaluate the alterations of root dentin permeability after exposure to different acids. Dentin permeability was measured after the following sequential steps: (1) treatment with EDTA for 3 minutes to obtain the maximum permeability; (2) root planing to create a smear layer; (3) exposure to different acidic substances for 5 minutes (vinegar, cola drink, lemon juice, white wine, and orange juice); and (4) brushing for 3 minutes. RESULTS: All acidic substances increased dentin permeability after root planing. Lemon juice produced higher values for permeability when compared to the other substances (P = .009); moreover, orange juice showed similar results (P < .02) except when compared to vinegar (P = .12). Brushing right after acid exposure significantly reduced dentin permeability except in the vinegar group (P = .07). CONCLUSION: Under the experimental conditions, dietary acids increased root dentin permeability, and immediate brushing reduced permeability levels.