Effect of photoactivation on the reduction of composite resin contamination.

Composite resins are predominantly marketed in developing countries in tube form, and the contents of the tube may be used in numerous procedures for different patients. This represents a problem because of the risk of cross-contamination. This study aimed to evaluate contamination in vitro of the internal contents of composite resin tubes in the dental clinics of a higher-education institution, as well as the effect of photoactivation on the level of contamination. Twenty-five tubes containing composite resin were randomly chosen (by lottery). From each tube, two samples of approximately 2 mm of composite resin were removed, and then one sample, but not the other, was photoactivated. These samples were plated on Brain-Heart Infusion (BHI), Sabouraud and MacConkey agars, and the plates were incubated at 37°C for 24-48 h. Colony counting and Gram staining were performed for subsequent microscopic identification of fungi and bacteria. The non-photoactivated composite resin group presented significantly higher microbial contamination in relation to the photoactivated composite resin group. The photoactivation of camphorquinone present in composite resin produces reactive oxygen species, which might promote cell death of contaminant microorganisms. Thus, although the same tube of composite resin may be used for a number of different patients in the dental clinics of developing countries, the photoactivation process potentially reduces the risk of cross-contamination.

Scutia buxifolia Reissek essential oil: in vitro antioxidant and antimicrobial activities.

The volatile oil from the stem bark of Scutia buxifolia (Rhamnaceae) has been obtained by hydrodistillation and analyzed by GC-MS. Twenty-one components were identified representing 99.93 % of the total oil composition, spathulenol (35.87%), ß-cubebene (17.26%), germacrene D (6.43%), linalool (5.19%), carvacrol (4.05%) were the main components of S. buxifolia essential oil. Antioxidant and antimicrobial properties of the essential oil were evaluated by free radical scavenging (DPPH) assay and micro broth dilution method, respectively. S. buxifolia essential oil presented interesting radical scavenging activity (IC50 = 15.03 ± 0.11 µg/mL). The antibacterial assay showed that S. buxifolia stem bark essential oil was moderately active against the Staphylococcus aureus and Micrococcus sp. (MIC = 500 µg/mL) and Escherichia coli (250 µg/mL). To the best of our knowledge, this is the first study on the composition, antioxidant and antimicrobial activities of essential oil from the S. buxifolia collected from Brazil.

Effect of Recreational Intervention on the Approach of Pediatric Patients in Dental Treatment: Analysis of Salivary Cortisol

Abstract Objective: To verify whether recreational interaction with pediatric patient before dental care influences cortisol levels and anxiety. Material and Methods: Twelve children were selected and divided into two groups: 6 children who had not previously received recreational intervention (Group I) and 6 children who received recreational intervention before dental care (Group II). Saliva was collected with Salivettes™ kits before and soon after dental care for the measurement of cortisol. Wilcoxon test was applied to verify the difference in salivary cortisol levels before and after the dental visit in the whole sample, and the Mann-Whitney U test was used to analyze the difference between groups I and II. A significance level of 0.05 was considered. Results: Among patients from Group I, 3 had their cortisol levels increased after dental care, 2 had their cortisol levels decreased, and the other 1 patient remained constant. All participants from Group II had no significant difference in cortisol levels pre- and post-procedure. Mean salivary cortisol level was higher in Group I, pre- and post-procedure, compared to Group II. Conclusion: Pediatric patients who participated in an interactive activity prior to dental care have a lower level of anxiety according to the salivary cortisol levels obtained, compared to patients who did not participate in recreation. The techniques for the dentist to approach the child control the anxiety of the patient and make the procedure calmer and less stressful for both of them.