Influence of new complete dentures on the touch perception threshold and quality of life of edentulous patients.

OBJECTIVE: To evaluate the touch perception threshold of the alveolar mucosa and quality of life of edentulous patients before (T0) and 30 days after (T1) the insertion of new complete dentures. BACKGROUND: Touch perception is important so that edentulous patients can detect the position of complete dentures in their mouth. MATERIALS AND METHODS: This study included 32 complete denture wearers with good oral and systemic health and no temporomandibular disorders for at least 5 years. At each time point (T0 and T1), two tests were performed (touch perception threshold and quality-of-life scale). The touch perception threshold (Von Frey or Semmes-Weinstein test) was assessed using nylon monofilaments on the regions of the alveolar mucosa of the maxilla and mandible. The Oral Health Impact Profile for edentulous individuals (OHIP-EDENT) was administered to evaluate oral health-related quality of life. RESULTS: In the maxilla and mandible, the touch perception thresholds for all regions of the alveolar mucosa were significantly lower at T1 than at T0. The OHIP-EDENT mean scores showed that the overall quality of life was significantly better at T1 (3.6) than at T0 (4.7), and a significant improvement in quality of life was observed in all domains of the OHIP-EDENT at T1. For touch perception threshold, effect sizes ranged from 0.4 to 0.8; and for quality of life, effect sizes ranged from 0.4 to 1.0. CONCLUSIONS: New complete dentures reduced the touch perception threshold of the alveolar mucosa of both edentulous arches and improved individuals' quality of life.

Incidence of peri-implant disease associated with cement- and screw-retained implant-supported prostheses: A systematic review and meta-analysis.

STATEMENT OF PROBLEM: Implant-supported fixed dental prostheses can be cement- or screw-retained on the implant or abutment, with advantages and disadvantages for each method. Cemented prostheses have been associated with peri-implant disease because cement remnants act as a reservoir for bacteria and hinder biofilm control. However, contrasting evidence has been presented regarding this association based on studies with varying designs, and a systematic review and meta-analysis is required. PURPOSE: The purpose of this systematic review and meta-analysis was to answer the focused question: In patients who received implant-supported prostheses, is the incidence of peri-implant diseases higher in cemented implant-supported prostheses than in screw-retained ones? MATERIAL AND METHODS: The search was conducted using the National Library of Medicine (MEDLINE-PubMed), SCOPUS, EMBASE, and ISI Web of Science databases. Randomized clinical trials (RCTs) that assessed the incidence of peri-implant disease in cement- and screw-retained prostheses were included. Two authors independently screened the titles and abstracts, and analyzed the full texts, extracted data, and assessed the risk of bias. The findings were summarized using meta-analyses with random effects, and the level of certainty of the evidence was determined using the grading of recommendations, assessments, development, and evaluations (GRADE) approach. RESULTS: The search yielded 4455 articles that met the inclusion criteria based on the title and/or abstract selection. A total of 6 RCTs were included for analysis. The meta-analysis revealed no significant difference between cement- and screw-retained prostheses for the risk of peri-implant mucositis (RR: 1.36, 95% CI: 0.42-4.38, P=.61). Similarly, no significant difference was observed between cement- and screw-retained prostheses for the incidence of peri-implantitis (RR: 1.00, 95% CI: 0.23-4.31, P=1.00). CONCLUSIONS: Moderate certainty evidence suggests that cement- and screw-retained prostheses present a similar risk for peri-implant mucositis and peri-implantitis.

Clinical outcomes of digital scans versus conventional impressions for implant-supported fixed complete arch prostheses: A systematic review and meta-analysis.

STATEMENT OF PROBLEM: With the growing use of digital scanning, an evaluation of the clinical impact of digital scans versus conventional impressions in complete arch implant-supported prostheses is needed. However, systematic reviews on this subject are lacking. PURPOSE: The purpose of this systematic review was to evaluate the scanning and impression times and the radiographic marginal bone loss over time associated with digital scans and conventional impressions for complete arch implant-supported fixed prostheses. MATERIAL AND METHODS: The search was performed in MEDLINE/PubMed, SCOPUS, EMBASE, and Web of Science. Only randomized clinical trials (RCTs) comparing digital scans and conventional impressions for complete arch prostheses were included in the review. The scan and impression times and marginal bone loss were analyzed through random effects meta-analysis. RESULTS: Six RCTs were included. The meta-analysis was conducted by using a standardized mean difference (MD) and indicated a statistically significant reduction in time for the digital scan group compared with the conventional group (MD 10.01 [7.46, 12.55], P<.001, I²=80%). The fact that digital scans were used did not lead to significant differences in radiographic marginal bone loss compared with conventional impressions after 6 months (MD -0.03 [-0.14, 0.08], P=.58, I²=0%), after 12 months (MD -0.06 [-0.24, 0.12], P=.12, I²=45%), and after 24 months (MD -0.12 [-0.32, 0.09], P=.28, I²=58%). CONCLUSIONS: Digital scans significantly reduced the time required compared with conventional impressions for complete arch implant-supported prostheses. Nevertheless, additional studies with more consistent methodologies are needed for confirmation. No significant differences were found in radiographic marginal bone loss between treatments performed with digital scans and conventional impressions.

Clinical reproducibility of different centric relation recording techniques in edentulous individuals: An observational cross-sectional study.

PURPOSE: To assess the reproducibility of four different centric relation (CR) recording techniques, and time spent performing each technique in edentulous individuals. MATERIALS AND METHODS: Four techniques were assessed: extraoral gothic arch (EOGA) tracing, intraoral gothic arch (IOGA) tracing, deglutition (D), and frontal manipulation with tongue elevation (FMTE). Twelve subjects participated in the study; four technique records were performed on each volunteer by the same operator. Each record was repeated three times, in the same period of the day, with a 30 min interval between each technique. The reproducibility of each technique was assessed by the tri-dimensional displacement of the position of the condylar housing (mandible condyle) to the wall of the condylar guide (glenoid cavity) in the semi-adjustable articulator (anteroposterior, mediolateral, and superior-inferior). The time spent on each technique was timed in seconds (from the beginning of each technique until the wax occlusion fixation). The analysis of variance (ANOVA) and the Tukey test were performed for anteroposterior displacement (two-way) and for time spent on CT recording techniques (one-way) (α < 0.05). Regarding mediolateral and superior-inferior displacements, the nonparametric Kruskal-Wallis was performed for the comparison between recording methods, whereas the Mann-Whitney test was performed for the comparison between sides (α < 0.05). RESULTS: The factor recording technique interfered with the anteroposterior displacement (ANOVA: α < 0.001; F = 11.396). The technique D (right side: 3.78 ± 0.69 mm; left side: 3.45 ± 0.74 mm) showed a statistically significant difference compared to the other techniques (EOGA: right side: 3.00 ± 0.00 mm; left side: 3.00 ± 0.00 mm; FMTE: right side: 2.81 ± 0.52 mm; left side: 2.82 ± 0.79 mm; IOGA: right side: 2.90 ± 0.65 mm; left side: 3.12 ± 0.44 mm). The time spent on the recording technique influenced the results (ANOVA: α < 0.001; F = 21.118). The IOGA (340.40 ± 163.41 s) and EOGA (285.93 ± 133.84 s) required more time compared to the D (86.00 ± 34.33 s) and FMTE (101.33 ± 36.72 s) techniques. CONCLUSION: Graphic recordings showed better reproducibility and accuracy of the position of the centric relation.

Cytotoxicity of cleaning agents for ocular prostheses.

BACKGROUND: Polymethylmethacrylate (PMMA) is the most used material for the manufacturing of eye prostheses. OBJECTIVES: To investigate the cytotoxicity of different cleaning agents for ocular prostheses on human conjunctival cells. MATERIAL AND METHODS: Six groups of specimens were created (saline, soap, 4% chlorhexidine, hydrogen peroxide, 1% triclosan, and citronella oil). Three specimens were made for each disinfectant at each disinfection period (1, 7, 15, 30, 60, and 90 days), totaling 108 specimens. Thus, the specimens were disinfected, with different disinfectants, for different periods of time. After each disinfection process, the specimens were washed with sterile distilled water. A human conjunctival cell line was grown on the acrylic resin specimens and then cytotoxicity tests (MTT and Neutral Red (NR)) were performed. A negative control (untreated cell cultures) and positive control (Tween 20) were created. Two-way analysis of variance (ANOVA) and Bonferroni test were performed (p < 0.05). RESULTS: For the MTT and NR tests, when there was a significant difference between the disinfectant and negative control, the disinfectant generated a significant reduction in cell proliferation most of the time. CONCLUSIONS: All reductions in cell proliferation caused by the disinfectants were clinically acceptable. All disinfectants tested in this study were found to be non-cytotoxic to human conjunctival cells.

Prevalence of anophthalmia etiological factors in patients treated in a reference center: A retrospective study.

Background: Ocular prosthesis rehabilitation has an important social, psychological, esthetic, and functional role. Congenital factors, trauma, and tumors, among others, can cause anophthalmia, and it is essential to identify the etiology to guide its prevention and treatment. Methods: The aim of this study was to retrospectively investigate the records of patients treated from 2013 to 2020 by the Oral and Maxillofacial Prosthesis Group, aiming to identify the prevalence of patients with anophthalmia and the etiology of their anophthalmia. After approval by the Human Research Ethics Committee, two calibrated researchers evaluated 520 records, identifying those from patients with anophthalmia. The inclusion criteria were records with complete and legible information from patients with anophthalmia and a description of their etiology. Descriptive statistics were performed, and etiological factors were categorized into trauma, congenital cause, end-stage eye disease, and tumor. Spearman's correlation was performed to verify the relation between gender and anophthalmia etiology, with a 5% significance level. Seventy-two records were included in the study. Results: It was observed that 33.4% of patients were women and 66.6% were men. The etiologies were physical trauma (52.4%), tumor (21.8%), end-stage eye disease (16.6%), and congenital cause (9.2%), and there was no correlation between gender and these etiologies (p = .301). Conclusion: Most of the cases identified were of traumatic origin, which allows the establishment of preventive and educational measures to avoid new cases of anophthalmia.

Antagonistic effect of isolated and commercially available probiotics on the growth of Candida albicans on acrylic resin denture surfaces.

STATEMENT OF PROBLEM: Biofilms can be retained on dental prostheses leading to the development of infections. The indiscriminate use of antifungal drugs can result in the development of microorganisms that are resistant to these antimicrobial agents. Whether probiotics are a suitable alternative for reducing the prevalence of oral candidiasis is unclear. PURPOSE: The purpose of this in vitro study was to evaluate the influence of 6 different live strains of probiotics and 2 commercially available probiotic supplements used for inhibiting the growth of Candida albicans biofilm in heat-polymerized acrylic resin denture base material and to determine whether biofilm byproducts modify the surface of specimens. MATERIAL AND METHODS: Biofilms of C. albicans were formed on acrylic resin specimens in the presence of probiotics and quantified by colony-forming units (CFUs), and the surface roughness (Ra) of the specimens was assessed before and after the formation of biofilms. The CFU and roughness data were analyzed by analysis of variance and the Tukey HSD test (α=.05). RESULTS: A significant decrease in the number (CFU/mL) of C. albicans cells was found when they were cultured with 4 probiotics: B. lactis (P=.045), B. longum (P<.001), L. casei (P<.001), and L. helveticus (P<.001) and with the commercially available probiotic Prolive (P=.05). The Ra of specimens decreased after exposure to different microbial biofilms (P≤.05) except in 3 experimental groups. CONCLUSIONS: In general, the tested probiotics had an antagonistic effect on the growth of C. albicans, and the surface of acrylic resin was altered after exposure to biofilm byproducts.

Effect of glaze and chlorhexidine on physical and mechanical properties of bis-acryl resin: An in situ study.

BACKGROUND: Temporary prosthesis protects the oral tissues, in addition to providing aesthetic look and masticatory function until a definitive prosthesis is manufactured. OBJECTIVES: To evaluate the effect of glaze and 0.12% chlorhexidine (CHX) on the physical and mechanical properties of bis-acryl, and to evaluate the antimicrobial efficacy of CHX. MATERIAL AND METHODS: Eighty specimens of bis-acryl resin were made. Over 40 of them the glaze was applied. One specimen with and 1 specimen without glaze were placed in niches of an appliance manufactured for each patient. Each of the 20 volunteers received 2 devices. Initially, the volunteers used one device and treated it with sucrose for 7 days (control), and later they used the other device and treated it with sucrose and CHX for 7 days (test). Color, microhardness, roughness, surface energy, and insoluble extracellular polysaccharides (EPS) tests were performed. All results were submitted to the Tukey's test, with the exception of the EPS results, which were submitted to the Student's t test. RESULTS: The ΔE00 of the unglazed control group was significantly higher than that of the unglazed test group. In all groups, a significant decrease in microhardness occurred over time. At both times, the glaze significantly increased the microhardness of the specimens (in all the glazed groups). At the final time, the test glaze group showed significantly higher microhardness compared with the control glaze group. Roughness in the groups without glaze increased significantly with CHX treatment over time. At both times, the glaze generated a significant reduction in roughness in the control and test groups. There was a significant reduction in surface energy over time in all groups. In most comparisons, the glazed groups showed significantly higher surface energy values compared with the unglazed control group. At the final time point, the unglazed test group showed a significantly higher surface energy value than the unglazed control group; and the glazed test group showed a significantly higher surface energy value compared with the glazed control group. The resins that received CHX had a significantly lower amount of biofilm. CONCLUSIONS: Color values were clinically acceptable in all tested groups. At both time points, the roughness values were clinically acceptable only in the glazed groups. Glaze increased the microhardness of the specimens. Microhardness and surface energy were reduced over time in all groups. Chlorhexidine can help prevent microhardness degradation. Glaze and CHX can increase surface energy. Chlorhexidine reduced the amount of bacterial biofilm.

Alcohol and light-polymerizing glaze effect on the physical and mechanical properties of a bisacrylate composite resin before and after immersion in chlorhexidine gluconate.

STATEMENT OF PROBLEM: The use of 0.12% chlorhexidine gluconate (CHX) may damage bisacrylate composite resin interim restorations, but whether they can be protected with an application of alcohol and/or the use of a glaze is unclear. PURPOSE: The purpose of this in vitro study was to evaluate the effect of applying a 70% alcohol solution on the physical and mechanical properties of a bisacrylate composite resin, with and without the application of a light-polymerizing glaze subjected to 0.12% CHX twice a day for 7 days. MATERIAL AND METHODS: Forty specimens of an autopolymerized bisacrylate composite resin were divided into 4 groups (n=10): Group C (without alcohol, without glaze), Group G (without alcohol, with glaze), Group A (with alcohol, without glaze), and Group AG (with alcohol, with glaze). All specimens were submitted to in vitro treatment with 0.12% CHX for 7 days, and tests of color alteration (ΔE00), microhardness, roughness, and surface were performed initially and after treatment. Data were submitted to analysis of variance (ANOVA) and the Tukey HSD test (α=.05). RESULTS: Group A had the lowest mean value of ΔE00 with a significant statistical difference from Group C. The groups with alcohol presented higher microhardness mean values compared with groups without alcohol in both periods of analysis, except for the groups with glaze in the final period. Group C showed higher mean roughness values in comparison with Group A in both periods. Group AG presented higher mean roughness values than Group G. Surface energy values did not vary significantly among groups, except between Groups C and A in the final period. CONCLUSIONS: The application of alcohol optimized the properties of the autopolymerized bisacrylate composite resin analyzed, with and without the application of glaze. Overall, the use of CHX changed the microhardness and roughness when the glaze was applied.

Community Science for Coastal Acidification Monitoring and Research.

Ocean and coastal acidification (OCA) present a unique set of sustainability challenges at the human-ecological interface. Extensive biogeochemical monitoring that can assess local acidification conditions, distinguish multiple drivers of changing carbonate chemistry, and ultimately inform local and regional response strategies is necessary for successful adaptation to OCA. However, the sampling frequency and cost-prohibitive scientific equipment needed to monitor OCA are barriers to implementing the widespread monitoring of dynamic coastal conditions. Here, we demonstrate through a case study that existing community-based water monitoring initiatives can help address these challenges and contribute to OCA science. We document how iterative, sequential outreach, workshop-based training, and coordinated monitoring activities through the Northeast Coastal Acidification Network (a) assessed the capacity of northeastern United States community science programs and (b) engaged community science programs productively with OCA monitoring efforts. Our results (along with the companion manuscript) indicate that community science programs are capable of collecting robust scientific information pertinent to OCA and are positioned to monitor in locations that would critically expand the coverage of current OCA research. Furthermore, engaging community stakeholders in OCA science and outreach enabled a platform for dialogue about OCA among other interrelated environmental concerns and fostered a series of co-benefits relating to public participation in resource and risk management. Activities in support of community science monitoring have an impact not only by increasing local understanding of OCA but also by promoting public education and community participation in potential adaptation measures.

Comparison of different methods for obtaining centric relation: a systematic review.

The objective of this study was to compare techniques of different methods of obtaining centric relation to verify which technique generates the greatest reproducibility of the centric relation. The PubMed/MEDLINE, Cochrane Library, SciELO, Scopus, and Web of Science databases were searched for articles published up to May 15, 2018. The search terms were combinations of "dental centric relation" with each of the following terms (individually): "reproducibility of findings"; "jaw relation record"; "chin point"; "gothic arch"; "bimanual manipulation"; "swallowing"; and "jig." The inclusion criteria included clinical studies in English that had to compare at least 2 techniques representing different methods for obtaining centric relation (based on the reproducibility of the centric relation) in individuals without temporomandibular dysfunction; and studies performed in individuals with complete or nearly complete dentition or complete edentulism. Methods (techniques) included in this study were guided methods (chin point guidance and bimanual manipulation); graphic methods (intraoral and extraoral gothic arch tracing); and physiologic methods (swallowing and tongue retrusion along the palate). A total of 1638 articles were identified. After the inclusion and exclusion criteria were applied, 7 articles were included in this review. None of the reviewed studies evaluated edentulous individuals. Two articles compared physiologic methods with guided methods; one concluded that the swallowing technique generates greater variability than guided methods, and the other concluded that there was no difference between the swallowing technique and chin point guidance. Of 5 articles comparing intraoral gothic arch tracing with guided methods, 2 showed similar results between different methods, 2 showed superior results for gothic arch tracing, and 1 showed superior results for the guided methods. Based on the guided methods and swallowing technique, it is not possible to conclude which technique can generate the greatest reproducibility of the centric relation. It is possible to suggest that in most cases intraoral gothic arch tracing is superior or equivalent when compared to guided methods.

Titanium versus ceramic implants for overdentures: a meta-analysis of prospective studies.

The aim of this study was to compare the use of titanium and ceramic implants for overdentures in terms of their failure rates, surface treatments, and marginal bone loss (MBL). The literature was searched using the PubMed, Scopus, and Cochrane databases up to October 2019. Clinical studies in which ceramic and titanium implants for overdentures were compared in terms of their failure rates, surface treatments, and MBL were included in the meta-analysis. The meta-analysis was performed based on the Mantel-Haenszel and inverse variance methods using a fixed-effects model and 95% confidence intervals. A total of 2747 publications were identified after the exclusion of duplicate articles. Fifteen were selected for full-text reading, and 2 were included in the review. Each of the 2 studies initially enrolled 24 patients, and a total of 38 patients (mean age of 62 years) were evaluated at the 1-year follow-up. A total of 112 titanium implants (success rate of 71.1%) and 146 ceramic implants (success rate of 65.9%) were placed. Twenty titanium implants failed, and an associated MBL of 0.15 mm was observed. For ceramic implants, 42 failures occurred, and an associated MBL of 0.33 mm was observed. Titanium implants provided better clinical results (less MBL and lower failure rate) for the support of overdentures than did ceramic implants.

Analysis of physical properties of facial silicones with different pigmentations submitted to nonthermal plasma treatment and accelerated aging.

STATEMENT OF PROBLEM: Exposure of silicone prostheses to environmental factors can alter their properties, affecting longevity. However, whether nonthermal plasma (NTP) can prevent these alterations is unclear. PURPOSE: The purpose of this in vitro study was to evaluate the surface roughness (Ra), sorption, solubility, and color stability (ΔE00) of the MDX4-4210 and A-120 silicones, with and without NTP treatment in accordance with an independent analysis of the use of 2 pigmentations. MATERIAL AND METHODS: One hundred sixty specimens were fabricated and distributed into 16 groups (n=10) as per the silicone, pigmentation, and NTP coating. The NTP was applied, and the Ra, sorption, solubility, and ΔE00 were evaluated before and after accelerated aging. ANOVA was used, and the HSD Tukey test was applied (α=.05). RESULTS: NTP generated an increase in roughness after aging, regardless of pigmentation or silicone. A-120 silicone without NTP showed a reduction in roughness after aging, regardless of pigmentation. For sorption and solubility, the bronze pigmentation (for A-120 and MDX4-4210) presented the smallest results after NTP treatment. For MDX4-4210 with pink pigmentation and NTP, sorption decreased and solubility increased. For A-120 with pink pigmentation and NTP, sorption and solubility increased. Sorption was reduced in all situations, except for A-120 with pink pigmentation, which increased. Regardless of the silicone used, solubility was reduced after NTP for bronze pigmentation. For A-120 and MDX4-4210 with pink pigmentation and NTP, the solubility increased. For both pigmentations, the NTP treatment promoted lower color alteration only for the A-120 silicone after accelerated aging (within the acceptability threshold). CONCLUSIONS: The NTP protocol of this study, which was applied to facial silicones, generated inconsistent results between the evaluated properties. Therefore, the NTP protocol used does not seem to be ideal for the treatment of silicone surfaces after aging.

Evaluation of the level of cortisol, capillary blood glucose, and blood pressure in response to anxiety of patients rehabilitated with complete dentures.

BACKGROUND: The aim was to analyze the levels of stress of edentulous patients through the state-trait anxiety inventory (STAI) and salivary flow through the visual analogue scale (VAS) xerostomia questionnaire, as well as analyze the levels of cortisol, capillary blood glucose, and blood pressure (BP) before and after the installation of complete dentures. METHODS: Fifty patients were evaluated. The STAI and VAS xerostomia questionnaire were applied before the installation of the prosthesis, on the day of its installation, and 1 month after the last recall visit. The BP measurement, as well as salivary and blood collections, were performed before the installation of the prothesis, and 1 month after the last recall visit. Data from the VAS xerostomia questionnaire and cortisol levels were submitted to ANOVA and the Tukey test (P = .05). Data from the STAI, as well as blood glucose and BP levels, were submitted to the Chi-square test (P = .05). The correlation between cortisol and blood glucose and between cortisol levels and BP was analyzed. RESULTS: There was no statistically significant association between the questions of the VAS xerostomia questionnaire, STAI-state and STAI-trait scores, or the periods analyzed. However, the cortisol level collected in the morning decreased after the installation of the prosthesis. There was a correlation between cortisol and blood glucose and BP levels. CONCLUSIONS: The installation of complete dentures was beneficial for patients since it was probably responsible for the cortisol level reduction.

Can Nonthermal Plasma Improve the Adhesion between Acrylic Resin for Ocular Prostheses and Silicone-Based Relining Material?

PURPOSE: To investigate the influence of nonthermal plasma (NTP) treatment on the tensile bond strength between heat-polymerized acrylic resin for ocular prostheses and silicone reliner, with and without the use of an adhesive primer. MATERIALS AND METHODS: One-hundred and sixty-four acrylic resin specimens were fabricated and randomly distributed into four groups according to the type of surface treatment: Sofreliner Primer, NTP, Sofreliner Primer + NTP, and NTP + Sofreliner Primer. Two specimens interposed with relining material (Sofreliner) formed one test sample to perform the tensile bond strength tests, before (initial) and after storage (final) in saline solution (37°C, 90 days, n = 10). Surface characterization was performed by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The failure type was classified as cohesive, adhesive, or mixed. The data were analyzed statistically using the two-way ANOVA and Tukey test, as well as the chi-squared test (α = 0.05), Bonferroni correction (α = 0.005), and Spearman correlation coefficient (α = 0.05). RESULTS: The SEM and EDS analyses showed the presence of a thin, homogenous organic film in the groups treated with NTP. The NTP + Sofreliner Primer group presented the largest bond strength mean values in the initial period (p < 0.05). Sofreliner Primer and NTP + Sofreliner Primer groups presented the first and second largest tensile bond strength mean values in the final period (p < 0.05), respectively. NTP + Sofreliner Primer group also had the largest number of cohesive (70%, initial) and mixed (90%, final) failures. CONCLUSIONS: The NTP treatment performed before the primer application enhanced the bond between the acrylic resin ocular prosthesis and the Sofreliner silicone-based reliner, even after 90 days of immersion in saline solution.

Rhipicephalus microplus infected by Metarhizium: unveiling hemocyte quantification, GFP-fungi virulence, and ovary infection.

Hemocytes, cells present in the hemocoel, are involved in the immune response of arthropods challenged with entomopathogens. The present study established the best methodology for harvesting hemocytes from Rhipicephalus microplus and evaluated the number of hemocytes in addition to histological analysis from ovaries of fungus-infected females and tested the virulence of GFP-fungi transformants. Different centrifugation protocols were tested, and the one in which presented fewer disrupted cells and higher cell recovery was applied for evaluating the effect of Metarhizium spp. on hemocytes against R. microplus. After processing, protocol number 1 (i.e., hemolymph samples were centrifuged at 500×g for 3 min at 4 °C) was considered more efficient, with two isolates used (Metarhizium robertsii ARSEF 2575 and Metarhizium anisopliae ARSEF 549), both wild types and GFP, to assess their virulence. In the biological assays, the GFP-fungi were as virulent as wild types, showing no significant differences. Subsequently, hemocyte quantifications were performed after inoculation, which exhibited notable changes in the number of hemocytes, reducing by approximately 80% in females previously treated with Metarhizium isolates in comparison to non-treated females. Complementarily, 48 h after inoculation, in which hemolymph could not be obtained, histological analysis showed the high competence of these fungi to colonize ovary from ticks. Here, for the first time, the best protocol (i.e., very low cell disruption and high cell recovery) for R. microplus hemocyte obtaining was established aiming to guide directions to other studies that involves cellular responses from ticks to fungi infection.

Clinical outcome of removable prostheses supported by mini dental implants. A systematic review.

INTRODUCTION: For many years, edentulous patients have had no other option than conventional dentures to reestablish their oral function. To avoid the need for bone graft surgery, some professionals have suggested the use of mini dental implants (MDIs) to support prostheses. The MDIs are narrow implants, ranging approximately from 1.8 to 2.9 mm in diameter. Recently, the promising results of mini implants regarding osseointegration and patient satisfaction have led clinicians to accept them as a definitive treatment option. OBJECTIVE: Therefore, the proposition of this systematic review was to assess information on the outcomes of MDIs supporting removable prostheses. METHODS: The PubMed and Cochrane databases were searched for articles published before September 2017, which yielded a total of 774 studies for analysis. After exclusion and inclusion criteria, 22 prospective studies were included in this systematic review. RESULTS: Most mini implants were placed in a flapless single-stage surgery and loaded immediately. Most studies reported failures in the first year and prosthetic complications. The mean survival rate of the selected studies was 95.6%, and mean follow-up was 22.8 months. CONCLUSION: The MDI-supported removable prostheses successfully improved patients' chewing and speaking ability, quality of life, and satisfaction, suggesting that MDIs are a viable and safe option to support removable prostheses in the mandibular arch.

Effects of mouth rehabilitation with removable complete dentures on stimulus perception and the electromyographic activity of the orbicularis oris muscle.

STATEMENT OF PROBLEM: Many elderly individuals are rehabilitated with removable complete dentures, which require an initial adaptation period for both oral perception and the perioral muscles. Studies assessing the changes in stimulus perception and the electromyographic (EMG) activity of the orbicularis oris muscle shortly after conventional complete denture insertion are lacking. PURPOSE: The purpose of this clinical study was to evaluate the effect of mouth rehabilitation with removable complete dentures on stimulus perception and the EMG activity of the orbicularis oris muscle. MATERIAL AND METHODS: This study was approved by the Human Research Ethics Committee of the Araçatuba Dental School (São Paulo State University). Fifteen participants who had worn their removable complete dentures for at least 5 years and needed rehabilitation with new prostheses were enrolled in the study. A perception questionnaire was applied, and surface EMG examinations of the orbicularis oris muscle during rest, suction of water with a straw, and pronunciation of the syllables /bah/, /mah/, /pah/, and the word 'Mississippi' were performed before (T0) and 30 (T1) and 100 (T2) days after insertion of the new prostheses. The data were analyzed with the Cochran Q test, McNemar test, 2-way repeated measures ANOVA, and honestly significant difference (HSD) Tukey test (α=.05). RESULTS: Significant improvement was reported in the perception questionnaire in terms of the oral discomfort sensation in the T2 period. EMG activity decreased during rest and suction after insertion of the new prostheses. A statistical difference between the upper and lower fascicles of the orbicularis oris muscle was detected, with a decrease of EMG activity between the T0 and T1 periods on the lower fascicle, except for when pronouncing the /pah/ syllable. CONCLUSIONS: Mouth rehabilitation with removable complete dentures decreased oral discomfort and, depending on the oral function, decreased or increased EMG activity of the orbicularis oris muscle. In addition, the lower fascicle was more active than the upper fascicle during rest and most functional activities.

Effect of nonthermal plasma on the properties of a resinous liner submitted to aging.

STATEMENT OF PROBLEM: The properties, such as softness and viscoelasticity, of a resinous reliner can deteriorate and extrinsic elements can become incorporated, making surface protection of the reliner material essential. PURPOSE: The purpose of this in vitro study was to evaluate the effect of low temperature plasma on Coe-Soft resinous reliner, submitted to aging in artificial saliva for up to 180 days. Sorption, solubility, Shore A hardness, surface energy, and topographic characteristics were analyzed by scanning electronic microscopy (SEM) and energy-dispersive spectroscopy (EDS). MATERIAL AND METHODS: Forty-four specimens were fabricated and distributed in 2 groups: nonplasma reliner (control group) and reliner with plasma (plasma group). The plasma was applied with a mixture of 70% hexamethyldisiloxane, 20% O, and 10% Ar. Total work pressure was maintained at a constant 20 Pa for 30 minutes of deposition. The specimens were analyzed before and after aging in an incubator with immersion in artificial saliva for 30, 90, and 180 days. The quantitative data were submitted to 2-way ANOVA and the Tukey test (α=.05), while qualitative data were compared visually. RESULTS: The control group presented lower Shore A hardness values only in the initial period, and surface energy increased with aging for both groups until 90 days. Greater sorption percentage values were encountered at 180 days in the plasma group. Greater solubility values were encountered in the control group in all periods. CONCLUSIONS: Plasma is an option for the protection of the material studied because the deposited film remained on the surface of the reliner material after aging.

Effect of different acidic solutions on the optical behavior of lithium disilicate ceramics.

STATEMENT OF PROBLEM: The stability of the optical characteristics of dental ceramics is essential. Degradation of these materials resulting from pH or temperature alterations in the oral cavity can lead to treatment failure. PURPOSE: The purpose of this in vitro study was to evaluate the color change (ΔE), the L* coordinate, the translucency parameter, and the contrast ratio of lithium disilicate ceramic exposed to commonly used and potentially colorant solutions. MATERIAL AND METHODS: Fifty lithium disilicate specimens were prepared and divided into 5 groups according to the immersion solution (artificial saliva, orange juice, cola, coffee, and red wine). Immersions in acidic beverages were alternated in a thermocycler with artificial saliva. The control group was immersed in artificial saliva at 37°C throughout the immersion period. After 168 hours of immersion, the color parameters were assessed with a spectrophotometer and calculated using the because system on 2 backgrounds (black and white) and in 2 time periods, before thermocycling and after thermocycling. Data were submitted to analysis of variance followed by the Tukey honest significant difference test (α=.05). RESULTS: Greater color change (ΔE) and lower L* coordinate values were observed after immersion in orange juice and cola. Regarding the translucency parameter and contrast ratio, the immersion in coffee resulted in greater opacity and lower translucency of the material. CONCLUSIONS: Alterations in the color stainability, the L* coordinate values, the translucency parameter, and the contrast ratio of the lithium disilicate ceramic were observed, according to the acidic solutions tested.