Effect of professional cleaning and dental brushing with or without fluoridated dentifrice on enamel remineralization

An in situ evaluation of the potential rehardening effect of fluoridated and non-fluoridated toothpastes with or without air polishing was conducted. Ten volunteers, using acrylic palatal appliances containing two bovine enamel blocks with artificial carious lesions, took part in this study. Four times a day, after the main meals and at night, the volunteers, in a habitual way, brushed their natural teeth with the dentifrice indicated to the experimental design and after that the appliances were put again into the mouth. They were divided into 4 different groups: G1 - control - non-fluoridated dentifrice; G2 - fluoridated dentifrice; G3 - non-fluoridated dentifrice, but having a previous prophylaxis using air polishing; G4 - fluoridated dentifrice and previous air polishing. The effects of treatments on enamel rehardening were evaluated in the blocks that were assessed by surface microhardness, and the percentage of surface microhardness change (%reh) was calculated in relation to the baseline values. The results showed that %reh was higher in the groups with fluoridated dentifrice, and professional prophylaxis did not have an additional effect in the groups of fluoridated dentifrices (p<0.05). The data suggested that, in the absence of fluoride, removal of dental plaque helped to increase the process of enamel rehardening.     

Effect of supragingival plaque control on subgingival microflora and gingivo-periodontal tissues

The aim of this study was to carry out a short term evaluation of the effect of supragingival plaque control on the subgingival microflora and gingivoperiodontal tissues in patients with moderate and severe periodontitis. A total of 92 sites from 23 patients were studied; patients ranged between 35 and 60 years of age (x 46.4 +/- 1.71). Plaque Index (PI), Gingival Index (GI), Bleeding on Probing (BP), Probing Depth (PD), and Attachment Level (AL) were measured. Subgingival microflora of the same sites was studied by dark field microscopy, and cultures in non-selective and selective media for Actinobacillus actinomycetemcomitans (Aa), Prevotella intermedia/nigrescens (Pi/n), Porphyromonas gingivalis (Pg) and Fusobacterium nucleatum (Fn). The patients were included in a supragingival plaque control program which included oral hygiene training and assessment, and professional control of supragingival plaque and calculus. After 28 days, measurement of clinical parameters and the microbiological study were repeated. The sites were divided according to baseline PD values into: Group 1 (5 mm), Group 2 (6 mm) and Group 3 (> or = 7 mm). Results revealed a significant reduction in PI scores, GI scores, PB and PD in groups 2 and 3. No significant difference in AL was observed in any of the three groups. PI scores were found to decrease significantly in group 1, and GI scores, BP and PD tended to decrease. A significant increase in coccoid cells and a significant decrease in motile rods and spirochetes, both small and total, was observed in groups 2 and 3. Group 1 showed a significant decrease in medium and total spirochetes. At the end of the study, a significant decrease in Pi/n was found in all three groups. Significant decreases were found in Pg and Fn in Groups 3 and 2 respectively. Although it holds true that supragingival plaque control reduced a potentially pathogenic subgingival microbiota, this effect was not sufficient to be compatible with healthy gingivoperiodontal tissues.     

Osteogenesis imperfecta and dentinogenesis imperfecta: associated disorders.

This paper presents a review of dentinogenesis imperfecta occurring in patients with osteogenesis imperfecta. The systemic manifestations and the oral aspects of dentinogenesis imperfecta in osteogenesis imperfecta are discussed, and an illustrative case is described.     

Microbiological culture analysis of the tongue anaerobic microflora in subjects with and without halitosis

Objective:  Determination of the microflora present on the tongue dorsum of subjects with and without halitosis using conventional microbiological culture methods.
Methods:  Twenty-one halitosis and 20 control patients were recruited using a strict clinical protocol. Samples were collected from the posterior dorsum of the tongue using a sterile brush. Each sample was vortex mixed for 30 s and serial 10-fold dilutions to 10⁻⁷ were carried out. Samples were plated onto fastidious anaerobe agar (FAA) and FAA enriched with vancomycin. These were incubated under anaerobic conditions for 10 days at 37°C. Strict anaerobes were identified by metronidazole sensitivity and bacteria were identified to genus level by a combination of colony morphology, Gram staining and biochemical and enzymatic tests (rapid ID 32 A).
Results:  The predominant species in test and control groups were Veillonella sp. and Prevotella sp. Greater species diversity was found in the halitosis samples compared with controls. The halitosis samples contained an increased incidence of unidentifiable Gram-negative rods, Gram-positive rods and Gram-negative coccobacilli.
Conclusions:  There was no obvious association between halitosis and any specific bacterial genus. The increased species diversity found in halitosis samples suggests that halitosis may be the result of complex interactions between several bacterial species. The role of uncultivable bacteria may also be important in contributing to this process.     

Quercetin ameliorates polychlorinated biphenyls‐induced testicular DNA damage in rats

Polychlorinated biphenyls (PCBs) are a group of environmental contaminants widely reported to cause gonadal toxicity in both humans and animals. This study investigated the amelioratory role of quercetin in PCBs‐induced DNA damage in male Wistar rats. Polychlorinated biphenyls were administered intraperitoneally at a dose of 2 mg kg^?1 alone or in combination with quercetin (orally) at 50 mg kg^?1 for 25 days. Quercetin modulation of PCBs‐induced gonadal toxicity was evaluated using selected oxidative stress indices, comet assay, measurement of DNA concentration and histology of the testes. Administration of PCBs alone caused a significant (P < 0.05) depletion in the total thiol level in testes of treated rats. Conversely, the levels of reactive oxygen species (ROS) and thiobarbituric acid reactive substances (TBARS) production were markedly elevated in testes of PCBs‐treated rats compared with control. Further, PCBs exposure produced statistically significant increases in DNA tail migration, degraded double‐stranded DNA (dsDNA) concentration and histological alterations of testes of the treated rats compared to control. Quercetin cotreatment significantly improved the testicular antioxidant status, decreased DNA fragmentation and restored the testicular histology, thus demonstrating the protective effect of quercetin in PCBs‐treated rats.     

The Effect of a Selective Inhibitor of Phosphodiesterase‐9 on Oxidative Stress,Inflammation and Cytotoxicity in Neutrophils from Patients with Sickle Cell Anaemia

The aim of the study was to investigate the possible anti‐inflammatory and antioxidant effects of BAY 73‐6691 on neutrophils from SCA patients. This study included 35 patients with a molecular diagnosis of SCA, whose neutrophils were isolated and treated with BAY 73‐6691 at the concentrations 100, 10, 1.0 and 0.1 μg/mL. LDH release and MTT assays were performed to verify cell viability. To evaluate oxidative stress, the following parameters were determined by spectrophotometric assays: NO and malondialdehyde (MDA) levels and activity of catalase, superoxide dismutase (SOD) and glutathione peroxidase (GPx). As inflammatory markers, myeloperoxidase (MPO) levels were evaluated by colorimetric assay and TNF‐α by enzyme immunoassay. The results showed that neutrophils from SCA patients not treated with hydroxyurea (HU) had significantly lower NO levels and catalase and SOD activity, as well as significantly higher MDA, MPO and TNF‐α levels when compared with neutrophils from SCA patients treated with HU and neutrophils from control group. Treatment of SCA neutrophils with BAY 73‐6691 resulted in 94%, 200% and 168% increase in NOx levels, SOD and catalase activity, respectively. In addition, there was a reduction of approximately 46% and 45% in TNF‐α and MPO levels, respectively. In SCAHU neutrophils, there was a 30% and 44% increase in NOx levels and SOD activity, respectively, and a 28% and 37% decrease in TNF‐α and MPO levels, respectively. However, these effects were observed at cytotoxic doses only. The results of this study are original and demonstrate that inhibition of phosphodiesterase‐9 in neutrophils from SCA patients with BAY 73‐6691 was able to increase the NO bioavailability and attenuate oxidative stress and inflammation in neutrophils from patients not treated with HU.     

Monitoring of demineralized dentin microhardness throughout and after bleaching

PURPOSE: To evaluate the effect of six bleaching agents: Nite White [NW] 10% and 22% Excel 2Z (Discus Dental), Rembrandt (REM) 10% and 22% (DenMat), Opalescence (OPA) 10% and 20% (Ultradent) and a placebo agent on demineralized dentin microhardness at different time intervals. METHODS: 105 human dentin slabs (3 x 3 mm) were embedded, planed and submitted to cariogenic challenges, composed of de- and remineralization cycles. For 42 days, specimens were exposed to bleaching agents, consisting of applying them daily for 8 hours, removing and storing the specimens in artificial saliva for 16 hours. At the end of the bleaching treatment, specimens were kept in artificial saliva for 14 days. Knoop Microhardness tests were performed on specimens' surface before (baseline), during (8 hours, 7, 14, 21, 28, 35 and 42 days) and after bleaching procedures (7 and 14 days). RESULTS: The ANOVA for split-plot showed significant effect on the interaction between bleaching agent and time (alpha =0.05). Tukey's test revealed no significant differences on demineralized dentin microhardness exposed to bleaching agents until Day 7. Regression analyses demonstrated that NW 10% and 22% and OPA 10% and 20% increased dentin microhardness in different magnitudes, whereas REM 10% and 22% induced mineral loss during bleaching agent application, followed by microhardness recovery in the post-treatment period.     

A functional interleukin-1 beta gene polymorphism is associated with chronic periodontitis in a sample of Brazilian individuals

BACKGROUND: Interleukin-1 beta (IL-1 beta) is a potent inflammatory mediator and an important polymorphism in the locus +3954 (C/T) of the human IL1 B gene has been shown to affect the levels of this cytokine. This functional polymorphism has been associated with the establishment of inflammatory diseases, including periodontal disease, in European, Asian and North American populations. OBJECTIVE: The aim of this study was to investigate the association between the IL1 B (+3954) gene polymorphism and the occurrence of different clinical forms of periodontitis in a sample of Brazilian individuals. METHODS: This study employed a cross-sectional design involving individuals from the State of Minas Gerais in the south-eastern region of Brazil. Genomic DNA was obtained from oral swabs of 129 individuals and amplified using the polymerase chain reaction (PCR) with specific primers flanking the locus +3954 of IL1 B. PCR products were submitted to restriction endonuclease digestion and analyzed by polyacrylamide gel electrophoresis, to distinguish alleles T and C of the IL1 B gene, allowing for the determination of the genotypes and detection of the polymorphism. RESULTS AND CONCLUSIONS: The chronic periodontitis group displayed a higher percentage of the T allele (28%) when compared to the aggressive periodontitis group (10.7%, chi(2)=5.24, p=0.02, OR=0.31, CI=0.11--0.88) and to control group (8.7%, chi(2)=7.11, p=0.007, OR=0.24, CI=0.08--0.73). Our data suggested that the polymorphism in the locus +3954 of IL1 B gene could be a risk factor for chronic periodontitis in a sample of Brazilian individuals.