Influence of Complete Denture Use on Respiratory Capacity: A Systematic Review.

AIM AND OBJECTIVE: This study aimed to determine whether the use of complete dentures has an influence on the respiratory capacity, assessed by the spirometry examination. MATERIALS AND METHODS: A systematic review was conducted following the Preferred Reporting Items for Systematic Review and Meta-Analysis and registered in the International Prospective Register of Systematic Reviews (CRD42021255224). The PICO question (population/exposure/comparison/outcome) was "Does the use of complete dentures influence the respiratory capacity of a toothless subject?" A search strategy was adapted for the PubMed/MEDLINE, The Cochrane Library, OpenGrey, Lilacs, Scopus, and Embase databases. Inclusion criteria were prospective and retrospective studies. The new castle ottawa (NOS) scale and the Methodological Index for Non-randomized studies were selected to assess the quality of the included studies. RESULTS: Four studies were selected, totalizing the evaluation of 242 participants, aged ranging from 40 to 73 years old. Two studies concluded that the use of complete dentures can negatively affect the respiratory capacity. One study stated that it did not interfere regardless of its use during spirometric measurements, and the other reported that dental prosthesis was required in cases of evaluation of the extrathoracic airways. CONCLUSION: The use of complete dentures did not represent relevant changes from the reference values for pulmonary function in the spirometry test. Considering the results of this review, it is not yet possible to establish a clinical protocol for the use of complete dentures during the test. CLINICAL SIGNIFICANCE: Oral rehabilitation with conventional complete dentures is widely used for the treatment of edentulism, especially in elderly patients. In addition, with aging, many complex changes in immunity and respiratory function contribute to the increase in the development of lung diseases. Therefore, it is important to establish a guidance regarding the use or not of the removable dental prostheses in the respiratory capacity test through spirometry examination.

Effect of exercise training on subjective parameters in patients with obstructive sleep apnea: a systematic review and meta-analysis.

Obstructive sleep apnea (OSA) has many effects on subjective parameters of the disease, such as reduction in quality of life (QoL), sleep quality (SQ), and increases in daytime sleepiness. Studies have reported the beneficial effect of exercise training on OSA severity; however, whether it improves subjective parameters remains unclear. The purpose of the present review was to investigate the effect of exercise training on QoL, daytime sleepiness, and SQ in adults with OSA by summarizing the results of clinical trials. The study adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and was registered in PROSPERO. A systematic review of the PubMed, Scopus, and Cochrane (CENTRAL) databases was conducted. Risk of bias analysis was performed using the Cochrane tool, and Review Manager version 5.2 (R Foundation for Statistical Computing, Vienna, Austria) was used to perform the meta-analysis. Of the 1573 studies initially retrieved, 8 relevant studies with 228 participants were included in the analysis. The studies presented moderate risk of bias. Exercise training significantly improved QoL (mean difference, 12.9 [95% confidence interval (CI) 6.4 to 19.5]) and SQ (mean difference, -2.0 [95% CI -3.6 to -0.5]), and reduced daytime sleepiness (mean difference, -3.7 [95% CI -6.1 to -1.2]), and OSA severity (mean difference, -11.4 [95% CI -13.4 to -9.4 events/h]). Thus, physical exercise training was effective in improving subjective parameters and reducing the severity of OSA. Additional randomized clinical trials, however, should be performed to confirm these findings.

Influence of Bariatric Surgery on Salivary Flow: a Systematic Review and Meta-Analysis.

Bariatric surgery is the most effective treatment for morbid obesity, but it can cause numerous adverse effects. This systematic review and meta-analysis aimed to evaluate whether bariatric surgery changes patient salivary flow. We searched for articles in the Web of Science, Pubmed/MEDLINE, and Scopus databases using the search terms "oral health AND bariatric surgery OR gastrectomy OR obesity surgery." We recovered 845 articles. After the removal of duplicates and exclusions, eight studies remained. Of them, five showed no significant difference in salivary flow values, two showed an increase in flow rate, and one showed a reduction in flow rate (p < 0.05). The results of the included studies showed no significant alteration in salivary flow rate for up to 24 months after bariatric surgery.

Efficacy of Dental Bleaching with Whitening Dentifrices: A Systematic Review.

A systematic review was performed to evaluate whether whitening toothpastes promote tooth whitening when compared to the use of conventional (nonbleaching) dentifrices. This review was registered at PROSPERO (CRD42017065132) and is based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. Electronic systematic searches of PubMed/MEDLINE, Scopus, and the Cochrane Library were conducted for published articles. Only randomized clinical trials in adults that compared the use of so-called whitening dentifrices to the use of nonwhitening dentifrices were selected. The outcome was tooth color change. Twenty-two articles from 703 data sources met the eligibility criteria. After title and abstract screening, 16 studies remained, after which a further five studies were excluded. In total, nine studies were qualitatively analyzed. Significant differences in tooth color change were found between the groups using whitening dentifrices and those using nonwhitening dentifrices. Within the limitations of this study, the evidence from this systematic review suggests that bleaching dentifrices have potential in tooth whitening. However, although many whitening dentifrices have been introduced into the dental market for bleaching treatments, it is important to analyze tooth surface and color changes when performing home bleaching.

Effect of Pressure, Post-Pressing Time, and Polymerization Cycle on the Degree of Conversion of Thermoactivated Acrylic Resin.

Herein, the effect of different post-pressing times and pressure in two cycles of polymerization on the degree of conversion (DC) of thermally activated acrylic resin (TRRA) is analyzed to optimize the polymerization of this material. After post-pressing for 0, 6, or 12 h, polymerization was performed with or without a pressure of 60 psi (0.41 MPa) in a short (4 h) or a long (11 h) cycle, totaling 12 groups. To determine the DC, PMMA specimens were analyzed by Fourier transform infrared spectroscopy. The influence of each factor alone on the DC was studied by experimental planning. The statistical tests used were three-way ANOVA, t-test, Tukey's test, and Levene's test, with a margin of error of 5%. Two groups prepared with post-pressing times of 12 h had the lowest DC (p < 0.001). Post-pressing times of 0 and 6 h did not yield statistically different results. Pressure increased the DC in only one group (long cycle +12 h, p=0.001). The short cycle resulted in a higher DC than the long cycle in 2 groups (with pressure +0 h, p=0.002; without pressure +6 h, p=0.015), while the long cycle yielded a statistically higher DC in only one group (with pressure +12 h, p < 0.001). The polymerization showed satisfactory DC in all 12 groups. Small differences found among the specimens indicate that the pressure, post-pressing time, and polymerization cycles herein were not influential factors for the DC of PMMA.

Pattern of humoral immune response to Plasmodium falciparum blood stages in individuals presenting different clinical expressions of malaria.

BACKGROUND: The development of protective immunity against malaria is slow and to be maintained, it requires exposure to multiple antigenic variants of malaria parasites and age-associated maturation of the immune system. Evidence that the protective immunity is associated with different classes and subclasses of antibodies reveals the importance of considering the quality of the response. In this study, we have evaluated the humoral immune response against Plasmodium falciparum blood stages of individuals naturally exposed to malaria who live in endemic areas of Brazil in order to assess the prevalence of different specific isotypes and their association with different malaria clinical expressions. METHODS: Different isotypes against P. falciparum blood stages, IgG, IgG1, IgG2, IgG3, IgG4, IgM, IgE and IgA, were determined by ELISA. The results were based on the analysis of different clinical expressions of malaria (complicated, uncomplicated and asymptomatic) and factors related to prior malaria exposure such as age and the number of previous clinical malaria attacks. The occurrence of the H131 polymorphism of the FcgammaIIA receptor was also investigated in part of the studied population. RESULTS: The highest levels of IgG, IgG1, IgG2 and IgG3 antibodies were observed in individuals with asymptomatic and uncomplicated malaria, while highest levels of IgG4, IgE and IgM antibodies were predominant among individuals with complicated malaria. Individuals reporting more than five previous clinical malaria attacks presented a predominance of IgG1, IgG2 and IgG3 antibodies, while IgM, IgA and IgE antibodies predominated among individuals reporting five or less previous clinical malaria attacks. Among individuals with uncomplicated and asymptomatic malaria, there was a predominance of high-avidity IgG, IgG1, IgG2 antibodies and low-avidity IgG3 antibodies. The H131 polymorphism was found in 44.4% of the individuals, and the highest IgG2 levels were observed among asymptomatic individuals with this allele, suggesting the protective role of IgG2 in this population. CONCLUSION: Together, the results suggest a differential regulation in the anti-P. falciparum antibody pattern in different clinical expressions of malaria and showed that even in unstable transmission areas, protective immunity against malaria can be observed, when the appropriated antibodies are produced.

Variants in the toll-like receptor signaling pathway and clinical outcomes of malaria.

BACKGROUND: Malaria is one of the most significant infectious diseases in the world and is responsible for a large proportion of infant deaths. Toll-like receptors (TLRs), key components of innate immunity, are central to countering infection. Variants in the TLR-signaling pathway are associated with susceptibility to infectious diseases. METHODS: We genotyped single nucleotide polymorphisms (SNPs) of the genes associated with the TLR-signaling pathway in patients with mild malaria and individuals with asymptomatic Plasmodium infections by means of polymerase chain reaction. RESULTS: Genotype distributions for the TLR-1 I602S differed significantly between patients with mild malaria and persons with asymptomatic infection. The TLR-1 602S allele was associated with an odds ratio (OR) of 2.2 (P= .003; P(corrected)= .015) for malaria among patients with mild malaria due to any Plasmodium species and 2.1 (P= .015; P(corrected)= .75) among patients with mild malaria due to Plasmodium falciparum only. The TLR-6 S249P SNP showed an excess of homozygotes for the TLR-6 249P allele in asymptomatic persons, compared with patients with mild malaria due to any Plasmodium species (OR 2.1; 95% confidence interval [CI], 1.1- 4.2; P= .01; P(corrected)= .05), suggesting that the TLR-6 249S allele may be a risk factor for malaria (OR, 2.0; 95% CI, 1.1-3.7; P=0.01; P(corrected)= .05). The TLR-9 -1486C allele showed a strong association with high parasitemia (P< .001). CONCLUSIONS: Our findings indicate that the TLR-1 and TLR-6 variants are significantly associated with mild malaria, whereas the TLR-9-1486C/T variants are associated with high parasitemia. These discoveries may bring additional understanding to the pathogenesis of malaria.

Antigenic polymorphism and naturally acquired antibodies to Plasmodium vivax merozoite surface protein 1 in rural Amazonians.

Merozoite surface protein 1 of Plasmodium vivax (PvMSP-1), a major target for malaria vaccine development, contains six highly polymorphic domains interspersed with conserved sequences. Although there is evidence that the sequence divergence in PvMSP-1 has been maintained over 5 million years by balanced selection exerted by the host's acquired immunity, the variant specificity of naturally acquired antibodies to PvMSP-1 remains poorly investigated. Here, we show that 15 recombinant proteins corresponding to PvMSP-1 variants commonly found in local parasites were poorly recognized by 376 noninfected subjects aged 5 to 90 years exposed to malaria in rural Amazonia; less than one-third of them had detectable immunoglobulin G (IgG) antibodies to at least one variant of blocks 2, 6, and 10 that were expressed, although 54.3% recognized the invariant 19-kDa C-terminal domain PvMSP-1(19). Although the proportion of responders to PvMSP-1 variants increased substantially during subsequent acute P. vivax infections, the specificity of IgG antibodies did not necessarily match the PvMSP-1 variant(s) found in infecting parasites. We discuss the relative contribution of antigenic polymorphism, poor immunogenicity, and original antigenic sin (the skew in the specificity of antibodies elicited by exposure to new antigenic variants due to preexisting variant-specific responses) to the observed patterns of antibody recognition of PvMSP-1. We suggest that antibody responses to the repertoire of variable domains of PvMSP-1 to which subjects are continuously exposed are elicited only after several repeated infections and may require frequent boosting, with clear implications for the development of PvMSP-1-based subunit vaccines.

Identification of novel consensus CD4 T-cell epitopes from clade B HIV-1 whole genome that are frequently recognized by HIV-1 infected patients.

OBJECTIVE: To identify promiscuous and potentially protective human CD4 T-cell epitopes in most conserved regions within the protein-coding genome of HIV-1 clade B consensus sequence. DESIGN: We used the TEPITOPE algorithm to screen the most conserved regions of the whole genome of the HIV-1 subtype B consensus sequence to identify promiscuous human CD4 T-cell epitopes in HIV-1. The actual promiscuity of HLA binding of the 18 selected peptides was assessed by binding assays to nine prevalent HLA-DR molecules. Synthetic peptides were tested with interferon-gamma ELISPOT assays on peripheral blood mononuclear cells (PBMC) from 38 HIV-1 infected patients and eight uninfected controls. RESULTS: Most peptides bound to multiple HLA-DR molecules. PBMC from 91% of chronically HIV-1 infected patients recognized at least one of the promiscuous peptides, while none of the healthy controls recognized peptides. All 18 peptides were recognized, and each peptide was recognized by at least 18% of patients; 44% of the patients recognized five or more peptides. This response was not associated to particular HLA-DR alleles. Similar responses were obtained in CD8 T-cell-depleted PBMC. CONCLUSION: In silico prediction of promiscuous epitopes led to the identification of naturally immunodominant CD4 T-cell epitopes recognized by PBMC from a significant proportion of a genetically heterogeneous patient population exposed to HIV-1. This combination of CD4 T-cell epitopes - 11 of them not described before - may have the potential for inclusion in a vaccine against HIV-1, allowing the immunization of genetically distinct populations.