Novel Cardiokine GDF3 Predicts Adverse Fibrotic Remodeling After Myocardial Infarction.

BACKGROUND: Myocardial infarction (MI) induces a repair response that ultimately generates a stable fibrotic scar. Although the scar prevents cardiac rupture, an excessive profibrotic response impairs optimal recovery by promoting the development of noncontractile fibrotic areas. The mechanisms that lead to cardiac fibrosis are diverse and incompletely characterized. We explored whether the expansion of cardiac fibroblasts after MI can be regulated through a paracrine action of cardiac stromal cells. METHODS: We performed a bioinformatic secretome analysis of cardiac stromal PW1+ cells isolated from normal and post-MI mouse hearts to identify novel secreted proteins. Functional assays were used to screen secreted proteins that promote fibroblast proliferation. The expressions of candidates were subsequently analyzed in mouse and human hearts and plasmas. The relationship between levels of circulating protein candidates and adverse post-MI cardiac remodeling was examined in a cohort of 80 patients with a first ST-segment-elevation MI and serial cardiac magnetic resonance imaging evaluations. RESULTS: Cardiac stromal PW1+ cells undergo a change in paracrine behavior after MI, and the conditioned media from these cells induced a significant increase in the proliferation of fibroblasts. We identified a total of 12 candidates as secreted proteins overexpressed by cardiac PW1+ cells after MI. Among these factors, GDF3 (growth differentiation factor 3), a member of the TGF-ß (transforming growth factor-ß) family, was markedly upregulated in the ischemic hearts. Conditioned media specifically enriched with GDF3 induced fibroblast proliferation at a high level by stimulation of activin-receptor-like kinases. In line with the secretory nature of this protein, we next found that GDF3 can be detected in mice and human plasma samples, with a significant increase in the days after MI. In humans, higher GDF3 circulating levels (measured in the plasma at day 4 after MI) were significantly associated with an increased risk of adverse remodeling 6 months after MI (adjusted odds ratio, 1.76 [1.03-3.00]; P=0.037), including lower left ventricular ejection fraction and a higher proportion of akinetic segments. CONCLUSIONS: Our findings define a mechanism for the profibrotic action of cardiac stromal cells through secreted cardiokines, such as GDF3, a candidate marker of adverse fibrotic remodeling after MI. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifier: NCT01113268.

Antimicrobial activity of essential oils against biofilms formed in dental acrylic resin: a systematic review of in vitro studies.

This study aimed to answer the question formulated according to the PICO strategy: 'Which essential oils show antimicrobial activity against biofilms formed on dental acrylic resin?' composed by population (dental acrylic resin), intervention (application of essential oils), comparison (denture cleansers, antifungal drugs, chlorhexidine, and oral mouthwashes), and outcome (antibiofilm activity). In vitro experimental studies evaluating the activity of EOs on biofilm formed on acrylic resin were included. PRISMA guidelines were followed, and the search was performed in the PubMed, Science Direct, Embase, and Lilacs databases and in the gray literature using Google Scholar and ProQuest in December 2023. A manual search of the reference lists of the included primary studies was performed. Of the 1467 articles identified, 37 were selected for full-text reading and 12 were included. Twelve EOs were evaluated, of which 11 showed activity against Candida spp., 3 against Staphylococcus aureus, and 1 against Pseudomonas aeruginosa. The EOs of Cymbopogon citratus, Cinnamomum zeylanicum, and Cymbopogon nardus showed higher action than chlorhexidine, C. nardus higher than Listerine, C. citratus higher than nystatin, and Melaleuca alternifolia higher than fluconazole and nystatin. However, chlorhexidine was more effective than Lippia sidoides and Salvia officinalis, sodium hypochlorite was more effective than L. sidoides, nystatin was more effective than Zingiber officinale, Amphotericin B more effective than Eucalyptus globulus and M. alternifolia. In conclusion, the EOs of C. zeylanicum, C. citratus, C. nardus, and M. alternifolia showed antimicrobial activity to reduce biofilm on dental acrylic resin.

Comparative analysis of the physical, chemical, and microbiological properties of Ti-6Al-4V disks produced by different methods and subjected to surface treatments.

STATEMENT OF PROBLEM: To improve the osseointegration of dental implants and reduce microbiological growth, different micro- and nanoscale surface topographies can be used. PURPOSE: The purpose of this in vitro study was to evaluate the influence of Ti-6Al-4V with 4 surfaces, machined (DU), machined+hydroxyapatite (DUHAp), machined+acid-alkali treatment (DUAA), and additive manufacturing (DMA), on the physical, chemical, and microbiological properties. MATERIAL AND METHODS: The topography of Ti-6Al-4V disks with the 4 surfaces was evaluated by scanning electron microscopy (SEM), the chemical composition by energy dispersive X-ray spectroscopy (EDS), and the crystalline structure by X-ray diffraction (XRD). Physical and chemical properties were analyzed by using wettability and surface free energy, roughness, and microbial adhesion against Staphylococcus aureus by colony forming units (CFU). One-way ANOVA analysis of variance and the Tukey multiple comparisons test were applied to evaluate the data, except CFU, which was submitted to the Kruskal-Wallis nonparametric test (α=.05). RESULTS: DU photomicrographs showed a topography characteristic of a polished machined surface, DUHAp and DUAA exhibited patterns corresponding to the surface modifications performed, and in DMA the presence of partially fused spherical particles was observed. The EDS identified chemical elements inherent in the Ti-6Al-4V, and the DUHAp and DUAA disks also had the ions from the treatments applied. XRD patterns revealed similarities between DU and DMA, as well as characteristic peaks of hydroxyapatite (HA) in the DUHAp disk and the DUAA. Compared with DU and DMA the DUHAp and DUAA groups showed hydrophilic behavior with smaller contact angles and higher surface free energy (P<.05). DMA showed a higher mean value of roughness, different from the others (P<.05), and a higher CFU for S. aureus (P=.006). CONCLUSIONS: DUHAp and DUAA showed similar behaviors regarding wettability, surface free energy, and bacterial adhesion. Among the untreated groups, DMA exhibited higher roughness, bacterial adhesion, and lower wettability and surface free energy.

Evaluation of axial displacement and torque loss of Morse-type prosthetic abutments of different angular tapers to their respective implants.

STATEMENT OF PROBLEM: The biomechanical stability of the implant-prosthesis assembly and its maintenance under function is a determining factor in the success of implant prosthesis rehabilitation, but studies of different angular tapers are lacking. PURPOSE: The purpose of this in vitro study was to evaluate the axial displacement and torque loss of prosthetic abutments with Morse-type connections of different angular tapers after thermomechanical cycling by using microcomputed tomography (µCT) and a digital torque wrench. MATERIAL AND METHODS: Eighteen Ø3.5×11.5-mm implants were embedded in polyvinyl chloride cylinders, and the 3 different types of abutments (n=6) with angular tapers of 11.5 degrees - Alvim Cone Morse (ACM-11.5), 16.0 degrees - Helix Gran Morse (HGM-16), and 24.0 degrees - Nobel Replace Conical Connection (NRC-24) were installed with the torque recommended by the manufacturers. To calculate the axial displacements of the abutments about the implants, zirconia maxillary canine crowns were fabricated using a computer-aided design and computer-aided manufacturing (CAD-CAM) system and cemented onto the abutments. Before and after thermomechanical cycling, the assemblies were scanned using microtomography (micro-CT) to assess axial displacement, and the torque losses were calculated after the abutments were finally unscrewed. A load of 100 N, frequency of 2 Hz, and 106 cycles with temperature variation of 5 °C to 55 °C were used for the thermomechanical cycling. Analysis of variance and the Tukey post hoc test (α=.05) were used for analysis. RESULTS: A significant difference was observed between the abutments for axial displacement, measured after thermomechanical cycling (P=.002). The ACM-11.5 abutment showed the highest mean value (134.1 ±58.7 µm), different from HGM-16 (63.3 ±26.1 µm) (P=.013) and NRC-24 (42.7 ±8.7 µm) (P=.002); the 2 latter groups were similar to each other (P=.618). For the torque losses, no significant difference was found among the abutments (P=.928), but there were significant differences for the thermomechanical cycling (before and after) (P<.001) in that the loss of torque was greater after thermocycling. CONCLUSIONS: The smaller the taper angle of the Morse-type prosthetic abutment, the greater its axial displacement, and the thermomechanical cycling significantly reduced pretorque, regardless of taper.

Influence of Er:YAG laser irradiation on surface properties of Ti-6Al-4V machined and hydroxyapatite coated.

Surface treatment by laser irradiation can change the topography of titanium; however, little is known about the changes it causes when applied to other coatings. This study aimed to evaluate the influence of Er:YAG laser irradiation on the surface properties of titanium-aluminum-vanadium (Ti-6Al-4V) discs. Four Ti-6Al-4V surfaces were evaluated (n = 10): CON-control, machined without surface treatment; LT-machined + laser treatment; HA-hydroxyapatite coating; and LT-HA-hydroxyapatite coating + laser treatment. For the laser treatment, an Er:YAG laser with a wavelength of 2940 nm, a frequency of 10 Hz, and an energy density of 12.8 J/cm2 was used. The morphology of the coating was investigated by scanning electron microscopy and the surface composition by energy-dispersive X-ray spectroscopy. The influence of laser irradiation treatment on roughness and wettability was also evaluated. The Er:YAG laser promoted a significant reduction in the roughness Sa (p < 0.05) and in the contact angle (p = 0.002) of the LT surface compared to the CON surface. On the LT-HA surface, a significant decrease in roughness was observed only for the Rz parameter (p = 0.015) and an increase in the contact angle (p < 0.001) compared to the HA surface. The use of the Er:YAG laser with the evaluated parameters decreased the surface roughness and improved the wetting capacity of machined without surface treatment. In the group with hydroxyapatite coating, the laser influenced the surface roughness only for the parameter Rz and reduced their wetting capacity.

Analysis of the influence of surface treatment by high-power laser irradiation on the surface properties of titanium dental implants: A systematic review.

STATEMENT OF PROBLEM: High-power laser irradiation may be a promising treatment for titanium dental implant surfaces. However, systematic reviews of the influence of high-power laser irradiation on the different properties of titanium surfaces are lacking. PURPOSE: The purpose of this systematic review was to analyze the influence of surface treatment by high-power laser irradiation on the surface properties of titanium and its alloys. MATERIAL AND METHODS: The PubMed, LILACS, COCHRANE library, and Science Direct databases were searched, and articles published in the last 10 years were included. Of the 725 articles initially identified, 27 were selected after full reading and the application of inclusion and exclusion criteria. RESULTS: The studies evaluated showed that laser irradiation treatment, depending on the settings and parameters used, promoted changes in the surface properties of titanium. In general, lower speed and a higher number of scans increased roughness. Laser surface treatment promoted the inclusion of more oxygen and improved the wetting capacity of titanium. Additionally, laser treatment improved the adherence of coatings. CONCLUSIONS: Changes in the surface properties of titanium after laser treatment have been demonstrated. However, determining protocols with specific parameters is necessary to optimize the results.

Effect of pores on cell adhesion to additively manufactured titanium implants: A systematic review.

STATEMENT OF PROBLEM: Titanium dental implants produced by additive manufacturing have pores that, depending on their size and quantity, may improve osteogenic cell adhesion without impairing mechanical properties. A systematic review of in vitro studies on this topic is lacking. PURPOSE: The purpose of this systematic review was to answer the question "What is the influence of pores on osteogenic cell adhesion on titanium surfaces produced by additive manufacturing?". MATERIAL AND METHODS: The study was designed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) 2020 standards and registered in the Open Science Framework (OSF) (osf.io/baw59). A manual search of published articles without language or time restrictions was conducted in November 2022 in the electronic databases PubMed, Scopus, ScienceDirect, Embase, and in the nonpeer-reviewed literature via Google Scholar. RESULTS: A total of 1338 initial results were found, and after removing duplicates and applying eligibility criteria, 13 articles were included in this review that, according to the Joanna Briggs Institute (JBI) tool, presented a low risk of bias. Pores with larger diameters provide greater a surface area that favors cell filopodia adhesion and has interconnection that optimizes the transport of nutrients and oxygen and bone cell activity. CONCLUSIONS: The presence of pores on the surface of titanium produced by additive manufacturing increases the adhesion, migration, proliferation, and viability of osteogenic cells.

Osseointegration in relation to drilling speed in the preparation of dental implants sites: A systematic review.

STATEMENT OF PROBLEM: The drilling speed used for preparing dental implants may affect bone-implant contact (BIC), implant stability quotient (ISQ), and bone area fraction occupancy (BAFO). Different rotational speeds and the presence or absence of irrigation during site preparation have been investigated, but an established protocol for achieving the best osseointegration results is lacking. PURPOSE: The purpose of this systematic review was to investigate the influence of drill rotational speed on bone drilling for dental implant placement and its relationship with osseointegration. MATERIAL AND METHODS: This review included the preferred reporting items for systematic reviews and meta-analyses (PRISMA) and was registered in the international prospective register of systematic reviews (PROSPERO) database. Electronic searches were performed in the MEDLINE (PubMed), Scopus, Science Direct, and Embase databases. The risk of bias was analyzed by using the systematic review center for laboratory animal experimentation (SYRCLE). RESULTS: A total of 1282 articles were found, and after removing duplicates and applying the eligibility criteria to in vivo articles on animals that addressed drilling speed and its relationship to osseointegration, 8 articles were selected for analysis. Of these, 5 articles showed no statistical differences, and 3 others showed significantly better osseointegration results by analyzing the parameters of BIC, BAFO, ISQs, and pull-out forces (PoFs). In all selected articles, high-speed drilling was performed with irrigation. CONCLUSIONS: Although drilling speed seems to affect bone perforation, no definitive protocol was found in the literature consulted. The results vary depending on the combination of different factors, including bone type, irrigation, and drilling speed.

In situ evaluation of microbial profile formed on Ti-6Al-4V additive manufacturing disks: 16S rRNA sequencing.

STATEMENT OF PROBLEM: Dental implants obtained by additive manufacturing may present changes in the microbiome formed. However, studies profiling the microbial communities formed on Ti-6Al-4V are lacking. PURPOSE: The purpose of this in situ study was to characterize the profile of the microbial communities formed on Ti-6Al-4V disks produced by additive manufacturing and machining. MATERIAL AND METHODS: Titanium disks produced by additive manufacturing (AMD) and machining (UD) were housed in the buccal region of removable intraoral devices. These devices containing both disks were used by eight participants for 96 hours. After every 24 hours of intraoral exposure, the biofilm that had formed on the disks was collected. The 16S rRNA genes from each specimen were amplified and sequenced with the Miseq Illumina instrument and analyzed. Total microbial quantification was evaluated by analysis of variance-type statistics using the nparLD package. The Wilcoxon test was used to evaluate alpha diversity (α=.05). RESULTS: A difference was found in the microbial communities formed on additively manufactured and machined disks, with a reduction in operational taxonomic units (OTUs) for the AMD group compared with the UD group. Firmicutes and Proteobacteria were the most abundant phyla. Of the 1256 genera sequenced, Streptococcus predominated on both disks. CONCLUSIONS: The microbiome of the biofilm formed on the Ti-6Al-4V disks was significantly influenced by the fabrication method. The AMD disks showed lower total microbial counts than the UD disks.

Mouse HSA+ immature cardiomyocytes persist in the adult heart and expand after ischemic injury.

The assessment of the regenerative capacity of the heart has been compromised by the lack of surface signatures to characterize cardiomyocytes (CMs). Here, combined multiparametric surface marker analysis with single-cell transcriptional profiling and in vivo transplantation identify the main mouse fetal cardiac populations and their progenitors (PRGs). We found that CMs at different stages of differentiation coexist during development. We identified a population of immature heat stable antigen (HSA)/ cluster of differentiation 24 (CD24)+ CMs that persists throughout life and that, unlike other CM subsets, actively proliferates up to 1 week of age and engrafts cardiac tissue upon transplantation. In the adult heart, a discrete population of HSA/CD24+ CMs appears as mononucleated cells that increase in frequency after infarction. Our work identified cell surface signatures that allow the prospective isolation of CMs at all developmental stages and the detection of a subset of immature CMs throughout life that, although at reduced frequencies, are poised for activation in response to ischemic stimuli. This work opens new perspectives in the understanding and treatment of heart pathologies.

Protein absorption on titanium surfaces treated with a high-power laser: A systematic review.

STATEMENT OF PROBLEM: The surface of titanium dental implants treated with a high-power laser has been reported to favor osseointegration, mainly by altering protein uptake. Despite the large number of articles that address the topic, the heterogeneity of methodologies and results makes an understanding of the treatment's benefits difficult, and a systematic review is needed. PURPOSE: The purpose of this systematic review was to further the knowledge on protein uptake on titanium surfaces that have undergone treatment with a high-power laser. MATERIAL AND METHODS: This review followed the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines and was registered with the Open Science Framework (OSF) (osf.io/gcbna). Searches were performed in PubMed, Scopus, Web of Science, Embase, and Google Scholar databases. The articles were selected in 2 steps by 2 independent reviewers according to the previously selected eligibility criteria. The risk of bias was analyzed by using the Joanna Briggs Institute (JBI)-adapted quasi-experimental study evaluation tool. RESULTS: The studies addressed have shown that applying a high-power laser to the implant surface, depending on its settings, generates topographical changes that can optimize the protein absorption process and thus accelerate the other biological processes. CONCLUSIONS: The studies identified in this systematic review showed that surface treatment with a high-power laser represents a promising technique with a positive influence on protein uptake and osseointegration.

Dental mini-implant designs to support overdentures: Development, biomechanical evaluation, and 3D digital image correlation.

STATEMENT OF PROBLEM: Custom mini-implants are needed for edentulous patients with extensive mandibular deficiencies where endosteal placement is not possible. However, the best design for these mini-implants is unclear. PURPOSE: The purpose of this in vitro study was to develop 2 dental mini-implant designs to support mandibular overdentures and evaluate the effect of their geometries on primary stability and stress distribution. MATERIAL AND METHODS: Two mini-implant designs were developed with changes in the shape, size, and arrangement of threads and chamfers. The experimental mini-implants were made of Grade V titanium alloy (Ti-6Al-4V), (Ø2.0×10 mm) and submitted to a nanoscale surface treatment. Thirty mini-implants (n=10) were placed into fresh swine bones: experimental-threaded, experimental-helical, and a commercially available product model (Intra-Lock System) as the control. The biomechanical evaluations of the experimental mini-implants were compared with those of the control in terms of primary stability, through insertion torque (IT), and with the pullout test. The analysis of stress distribution was performed by using the method of 3D digital image correlation under 250-N axial load and 100-N oblique (30-degree angled model) load. The data were analyzed by ANOVA and the Tukey HSD test (α=.05). RESULTS: The IT and pullout test presented a statistically significant difference for all mini-implants (P<.05), with higher IT for the experimental-threaded and maximum pullout force for the control, followed by threaded (P=.001) and helical (P=.001). Regarding the 3D digital image correlation, a lower incidence of stress was found in the cervical third for all mini-implants. No statistically significant differences were found between the designs evaluated (P>.05). CONCLUSIONS: Comparing the experimental mini-implants with the commercially available control, the experimental-threaded model presented greater primary stability, and all mini-implants showed less stress in the cervical third.

In vitro assessment of polyetheretherketone for an attachment component for an implant-retained overdenture.

STATEMENT OF PROBLEM: Frequent maintenance because of the limited lifetime of overdenture attachments with O-rings has led to the development of materials that might improve their functionality and longevity. However, testing of newly developed attachment materials is lacking. PURPOSE: The purpose of this in vitro study was to evaluate a newly developed attachment made of polyetheretherketone (PEEK) for an implant-retained overdenture. MATERIAL AND METHODS: Specimens of PEEK, polyacetal, and Teflon O-ring materials were prepared for analysis of roughness, surface hardness, and compressive strength. For the fatigue resistance test, new specimens based on acrylic resin were subjected to 2880 insertion and removal cycles. Compression and roughness data were compared with the Kruskal-Wallis and Dunn post hoc test; hardness data with ANOVA and t test; and fatigue and stereomicroscopy with ANOVA with repeated measures, t test, and Bonferroni adjustment (α=.05). RESULTS: Polyacetal had the lowest surface roughness (P=.038). There was a significant difference in hardness among the materials (P<.05). PEEK presented the highest compressive strength among the materials (P<.001). For the fatigue resistance, only polyacetal showed a difference between the initial time-point (P<.05) and subsequent time-points. Polyacetal had a higher fatigue resistance than Teflon (P<.001) and PEEK (P<.05). Regarding the internal deformation of the attachments, a significant difference was observed among the materials (P<.05). CONCLUSIONS: PEEK showed promising results regarding the physicomechanical properties necessary for use as an overdenture attachment when compared with other evaluated materials. In addition, the PEEK attachment showed results comparable to those in the control group (O-rings) in terms of retention.

Stress Distribution Analysis of Novel Dental Mini-Implant Designs to Support Overdenture Prosthesis.

This study aimed to test and compare 2 novel dental mini-implant designs to support overdentures with a commercial model, regarding the stress distribution, by photoelastic analysis. Three different mini-implant designs (Ø 2.0 mm × 10 mm) were tested: G1-experimental threaded (design with threads and 3 longitudinal and equidistant self-cutting chamfers), G2-experimental helical (design with 2 long self-cutting chamfers in the helical arrangement), and G3-Intra-Lock System. After including the mini-implants in a photoelastic resin, they were subjected to a static load of 100 N under two situations: axial and inclined model (30°). The fringe orders (n), that represents the intensity of stresses were analyzed around the mini-implants body and quantified using Tardy's method that calculates the maximum shear stress (τ) value in each point selected. In axial models, less stress was observed in the cervical third mini-implants, mainly in G1 and G2. In inclined models (30°), higher stresses were generated on the opposite side of the load application, mainly in the cervical third of G2 and G3. All mini-implant models presented lower tensions in the cervical third compared with the middle and apical third. The new mini-implants tested (G1 and G2) showed lower stresses than the G3 in the cervical third under axial load, while loading in the inclined model generated greater stresses in the cervical of G2.

Effect of Auricular Acupuncture on the Reduction of Symptoms Related to Sleep Disorders, Anxiety and Temporomandibular Disorder (TMD).

BACKGROUND: Auricular acupuncture (AA) is a complementary/integrative therapy, and can be used as adjuvant treatment in sleep disorders, anxiety and the painful symptomatology of temporomandibular disorders (TMDs). OBJECTIVE: The aim of this investigation was to evaluate the effectiveness of AA in reducing the symptoms of sleep disorders, anxiety and TMDs by applying the Fletcher and Luckett, Beck-BAI and RDC/TMD questionnaires: Axis II, respectively. DESIGN: This was a nonrandomized clinical trial in which AA was administered to patients between the ages of 20 and 45 years from the School of Dentistry at Ribeirão Preto, São Paolo, Brazil, who had at least one of the following: sleep disorder, anxiety or TMD. INTERVENTION: Mustard seeds were applied to predetermined auricular acupoints including: Shen Men, neurovegetative system (sympathetic), kidney, anxiety, stomach, maxilla and mandible, liver and stress, once a week for 8 weeks. OUTCOME MEASURES: To analyze the reduction in sleep disorder symptoms, we used the Fletcher and Luckett questionnaire; for anxiety symptoms, the Beck-BAI questionnaire, and for the degree of chronic TMD pain, the RDC/TMD (Axis II) questionnaire. RESULTS: Data on sleep, anxiety and TMD disorders were analyzed via Fisher's exact, Wilcoxon and Chi-Square non-parametric tests (α = 0.05), respectively. Reduction in sleep disorder symptoms after the proposed intervention was verified, showed a statistically significant difference (P = .014). There was a reduction in mean anxiety score and a decrease in painful TMD symptoms, but no significant difference (P = .50; P = .947, respectively) before and after AA. CONCLUSION: In our study, AA was effective in reducing sleep disorder symptoms and our data suggests some relief of symptoms of anxiety and TMD pain.

Influence of chemical composition on cell viability on titanium surfaces: A systematic review.

STATEMENT OF PROBLEM: A consensus on which dental implant alloy and surface treatment provide the best cell viability is unclear. PURPOSE: The purpose of this systematic review was to provide information on the influence of surface and intrinsic titanium alloy chemical components on cell viability. MATERIAL AND METHODS: The PubMed, LILACS, COCHRANE library, and Science Direct databases were electronically searched for the terms dental implants AND titanium AND cytotoxicity. Inclusion criteria were research articles that studied titanium or its alloys for chemical composition and cell viability and were published in English between 1999 and 2019. Articles that did not study titanium and its alloys, articles with nondental or biomedical implants, and articles that were not found in their entirety were excluded. RESULTS: A total of 1226 articles selected by title or abstract according to the inclusion and exclusion criteria resulted in 51 articles that were reduced to 27 after reading in full. The treatments analyzed were arc fusion, electron beam physical deposition, plasma electrolytic oxidation, coating addition, micro arc oxidation, anodization, thermochemical process, BMP-2 immobilization, pressure-assisted sintering, and alkali heat treatment. CONCLUSIONS: The evaluated literature did not allow a determination of the best surface treatment for cell viability because of the heterogeneity of the studies regarding the type of alloy, cell used in the MTT assay, study, and implant purpose (biomedical or dental). The cytotoxic effect of chemical components was dependent on dose, time, size, temperature, and cell type. The niobium, tantalum, zirconium, and molybdenum elements have been most often added in the development of less toxic Ti alloys with lower modulus of elasticity and increased strength.

Effect of saliva and beverages on the surface roughness and hardnessof acrylic resin modified with nanomaterial.

PURPOSE: To evaluate the surface roughness and hardness of thermopolymerized acrylic resin incorporated with nanostructured silver vanadate (AgVO3) subjected to saliva and beverages. METHODS: The 128 specimens (5×5×2 mm) were prepared in thermopolymerized acrylic resin, according to the AgVO3 concentrations (n=32): 0%, 2.5%, 5% and 10%. The roughness and hardness were analyzed before and after immersion in saliva, Coca-Cola, orange juice and red wine, for 12 and 24 days. 2-way ANOVA and Bonferroni test (α= 0.05) were performed. RESULTS: After 12 days, Coca-Cola caused the highest roughness increase in the 2.5% group. The 10% group with saliva presented a higher roughness increase (P= 0.009). The control presented a decrease in roughness when in beverages (P< 0.05). After 24 days, orange juice and Coca-Cola produced a higher decrease in roughness in the control group (P< 0.05). After 12 days, saliva and wine produced a higher decrease in hardness of the 2.5% group (P< 0.05). Coca-Cola produced a decrease in hardness and wine an increase in hardness in the group with 10% AgVO3 concentration (P< 0.05). After 24 days, the group with 2.5% presented the highest decrease in hardness (P< 0.05). The immersions produced decreased hardness in the acrylic resin. Initially, there was an increase in roughness, however, over time, it decreased. CLINICAL SIGNIFICANCE: The control of oral biofilm is fundamental for the maintenance of the patient's oral health; however the incorporation of antimicrobial nanomaterial into prosthetic materials frequently exposed to saliva and beverages in the oral cavity interfered with the physical-mechanical properties of the products tested.

Effect of nanomaterial incorporation on the mechanical and microbiological properties of dental porcelain.

STATEMENT OF PROBLEM: Dental porcelain restorations are subject to biological failures related to secondary caries and periodontal disease leading to prosthesis replacement. PURPOSE: The purpose of this in vitro study was to explore the microbiological and mechanical properties of dental porcelain incorporated with different percentages of silver vanadate (ß-AgVO3) through microbiological analysis, roughness tests, and the Vickers microhardness test. MATERIAL AND METHODS: IPS InLine porcelain specimens were made by using a cylindrical Teflon matrix in the dimensions of 8×2 mm. For the control group, the porcelain was manipulated according to the manufacturer's instructions. The groups incorporating the nanomaterial were prepared with 2.5%, 5%, and 10% of ß-AgVO3, which was added proportionally by mass to the porcelain powder. In vitro microbiologic analysis, roughness tests, and the Vickers microhardness test were performed. RESULTS: Against Streptococcus mutans, the control group showed no inhibition halo (0 mm). All groups with AgVO3 showed a zone of inhibition, the highest for the group with 10% (30 mm) and then the groups with 2.5% (9 mm) and 5% (17 mm). For Vickers microhardness, no statistically significant difference (P<.05) was observed between the evaluated groups. The group with 10% of AgVO3 had the highest mean roughness and was statistically different (P<.001) from the other groups. CONCLUSIONS: Adding ß-AgVO3 to dental porcelain demonstrated antimicrobial effectiveness at all concentrations (2.5%, 5%, and 10%), with no effect on Vickers microhardness. The 10% group had higher roughness than the other groups.

Retention force and deformation of an innovative attachment model for mini-implant-retained overdentures.

STATEMENT OF PROBLEM: The gradual loss of retention and the need for periodic replacement of attachment-system components are the most frequent complications in implant-supported overdentures. PURPOSE: The purpose of this in vitro study was to develop a new attachment system for overdentures with polymeric materials and compare its retention and deformation with a conventional O-ring attachment system. MATERIAL AND METHODS: A matrix with 2 mini-implants with ball abutments was used to simulate the mandibular border during a fatigue resistance test. A total of 60 polyacetal (n=20), polytetrafluoroethylene (n=20), and conventional O-ring (n=20) attachments were captured in pairs with acrylic resin and subjected to 3625 insertion and removal cycles, simulating 30 months of overdenture use. The internal and external deformations of the attachments were assessed using an optical stereomicroscope. One-way ANOVA and the Tukey honestly significant difference tests were used for statistical evaluation (α=.05). RESULTS: The polyacetal attachment system showed the highest retention (P<.001), followed by the O-ring and polytetrafluoroethylene attachments. The O-ring attachments exhibited the lowest deformation (P<.001), and the polyacetal attachments had the highest internal deformation (P<.001). CONCLUSIONS: The newly developed polyacetal attachment model increased the retention of mini-implant-retained overdentures, and despite the deformation experienced, the retention period appears to be better than that of conventional systems.

Surface treatment of implant materials with antimicrobial nanoparticulates.

This study analyzed nanostructured silver vanadate (AgVO3) films on certain substrate surfaces found in dental implant devices in order to see if these films promote antimicrobial activity. Enamel and glaze vehicles were used to apply the nanomaterial (0.0% [control], 2.5%, 5.0%, and 10.0% concentrations) on 3 substrates (280 specimens per substrate): polytetrafluoroethylene (PTFE), polyacetal, and acrylic resin. An agar diffusion method was performed in triplicate to determine the antimicrobial activity against 8 microorganisms. Physical behavior and morphologic properties were also analyzed. The growth of Pseudomonas aeruginosa, Escherichia coli, Streptococcus mutans, Enterococcus faecalis, and Staphylococcus aureus was inhibited with the application of AgVO3. For Candida albicans, Porphyromonas gingivalis, and Prevotella intermedia, no antimicrobial activity was observed. Except for S mutans, the type of substrate did not influence the microbiologic results. The glaze showed greater antimicrobial efficacy against S aureus, E faecalis, and S mutans than did the enamel vehicle (P < 0.05). Films with 10% AgVO3 showed greater antimicrobial activity (P < 0.05). The choice of substrate or vehicle did not influence the surface roughness (P > 0.05); however, the application of 10% AgVO3 caused greater surface change (P < 0.05). The application of the nanomaterial did not influence the surface hardness of substrates when compared with the control group (P > 0.05). The use of the glaze as a vehicle provided higher hardness values (P < 0.05).