Chitosan coatings on titanium-based implants - From development to characterization and behavior: A systematic review.

Chitosan is a promising natural polymer for coatings, it combines intrinsic antibacterial and pro-osteoblastic properties, but the literature still has a gap from the development to behavior of these coatings, so this systematic review aimed to answer, "What is the relationship between the physical and chemical properties of polymeric chitosan coatings on titanium implants on antibacterial activity and osteoblast viability?". PRISMA guidelines was followed, the search was applied into 4 databases and grey literature, without the restriction of time and language. The selection process occurred in 2 blinded steps by the authors. The criteria of eligibility were in vitro studies that evaluated the physical, chemical, microbiological, and biological properties of chitosan coatings on titanium surfaces. The risk of bias was analyzed by the specific tool. Of 734 potential articles 10 were included; all had low risk of bias. The coating was assessed according to the technique of fabrication, FT-IR, thickness, adhesion, roughness, wettability, antibacterial activity, and osteoblast viability. The analyzed coatings showed efficacy on antibacterial activity and cytocompatibility dependent on the class of material incorporated. Thus, this review motivates the development of time-dependent studies to optimize manufacturing and allow for an increase in patents and availability on the market.

Association between anxiety and temporomandibular dysfunction in adult patients - a systematic review.

OBJECTIVE: Anxiety tends to increase muscle tension and painful symptoms; however, its symptoms can be associated with temporomandibular dysfunction (TMD). Therefore, it is crucial for professionals to identify the presence of both comorbidities and determine whether they are related. This study aims to systematically evaluate the literature and answer the question: "Is there an association between anxiety and TMD in adults?" METHODS: The study followed the PRISMA protocol and was registered in PROSPERO. The custom search was performed in PubMed, Embase, Scopus, and Lilacs databases, as inclusion criteria observational studies that evaluated the association between anxiety and TMD in adults. RESULTS: A total of 1640 articles were found. After removing duplicates, 988 were evaluated by title and abstract. Of these, 28 were selected for reading in full, of which 13 were included in the present review. CONCLUSION: The association of anxiety with TMD is positive, except for the minority indicating a low relationship between the disorders, which is explained by neuroscience.

Antimicrobial gel with silver vanadate and silver nanoparticles: antifungal and physicochemical evaluation.

Aim: To develop a ß-AgVO3 gel and evaluate its physicochemical stability and antifungal activity against Candida albicans. Materials & methods: The gel was prepared from the minimum inhibitory concentration (MIC) of ß-AgVO3. The physicochemical stability was evaluated by centrifugation, accelerated stability (AS), storage (St), pH, syringability, viscosity and spreadability tests and antifungal activity by the agar diffusion. Results: The MIC was 62.5 µg/ml. After centrifugation, AS and St gels showed physicochemical stability. Lower viscosity and higher spreadability were observed for the higher ß-AgVO3 concentration and the minimum force for extrusion was similar for all groups. Antifungal effect was observed only for the ß-AgVO3 gel with 20xMIC. Conclusion: The ß-AgVO3 gel showed physicochemical stability and antifungal activity.

We used silver and vanadium to make a gel that can kill fungi in the mouth. We looked at the color of the gel, it's smell and also checked how well it lasted. The gel turned yellow and had no smell and did not spoil for at least 2 months. When we tested the gel against a type of fungus, it worked as well as another medicine called chlorhexidine, which is sold in pharmacies. But when we compared it with another medicine called nystatin, our gel was not as effective in killing the fungus.

Titanium: A systematic review of the relationship between crystallographic profile and cell adhesion.

Dental implant surface properties such as roughness, wettability, and porosity ensure cell interaction and tissue integration. The clinical performance of dental implants depends on the crystallographic texture and protein and cell bonds to the substrates, where grain size, orientation, and inclination are parameters responsible for favoring osteoblast adhesion and limiting bacterial adhesion. The lack of consensus on the best crystallographic plan for cell adhesion prompted this systematic review, which aims to answer the following question: "What is the influence of the crystallographic plane on titanium surfaces on cell adhesion?" by evaluating the literature on the crystallographic characteristics of titanium and how these dictate topographical parameters and influence the cell adhesion of devices made from this material. It followed the Preferred Reporting Standards for Systematic Reviews and Meta-Analyses (PRISMA 2020) registered with the Open Science Framework (OSF) (osf.io/xq6kv). The search strategy was based on the PICOS method. It chose in vitro articles that analyzed crystallographic structure correlated with cell adhesion and investigated the microstructure and its effects on cell culture, different crystal orientation distributions, and the influence of crystallinity. The search strategies were applied to the different electronic databases: PubMed, Scopus, Science Direct, Embase, and Google Scholar, and the articles found were attached to the Rayyan digital platform and assessed blindly. The Joanna Bringgs Institute (JBI) tool assessed the risk of bias. A total of 248 articles were found. After removing duplicates, 192 were analyzed by title and abstract. Of these, 18 were selected for detailed reading in their entirety, 9 of which met the eligibility criteria. The included studies presented a low risk of bias. The role of the crystallographic orientation of the exposed faces in a multicrystalline material is little discussed in the scientific literature and its impact is recognized as dictating the topographical characteristics of the material that facilitate cell adhesion.

Microstructural characterization, mechanical and microbiological properties of acrylic resins added with reduced graphene oxide.

To evaluate the microstructural characterization, mechanical properties and antimicrobial activity of acrylic resins incorporated with different concentrations of reduced graphene oxide (rGO). Specimens were made of self-cured and heat-cured acrylic resins for the control group and concentrations of 0.5%, 1%, and 3%. The microstructural characterization was evaluated by scanning electron microscopy (SEM) and energy-dispersive X-ray (EDS). For mechanical testing, flexural strength, and Knoop hardness tests were performed. Microbiological evaluations were performed by colony forming units (CFU) analysis, tetrazolium salt reduction (XTT), and SEM images. The modified acrylic resins showed increased mechanical properties at low concentrations (p < 0.05) and with reduced S. mutans (p < 0.05). Reduced graphene oxide interfered with the mechanical performance and microbiological properties of acrylic resins depending on the concentration of rGO, and type of polymerization and microorganism evaluated. The incorporation of graphene compounds into acrylic resins is an alternative to improve the antimicrobial efficacy and performance of the material.

Structure-properties correlation of acrylic resins modified with silver vanadate and graphene.

This study aimed to incorporate ß-AgVO3 and rGO into self-curing (SC) and heat-curing (HC) acrylic resins and to evaluate their physicochemical, mechanical, and antimicrobial properties while correlating them with the characterized material structure. Acrylic resin samples were prepared at 0 % (control), 0.5 %, 1 %, and 3 % for both nanoparticles. The microstructural characterization was assessed by scanning electron microscopy (SEM) (n = 1) and energy dispersive X-ray spectroscopy (EDS) (n = 1). The physicochemical and mechanical tests included flexural strength (n = 10), Knoop hardness (n = 10), roughness (n = 10), wettability (n = 10), sorption (n = 10), solubility (n = 10), porosity (n = 10), and color evaluation (n = 10). The microbiological evaluation was performed by counting colony-forming units (CFU/mL) and cell viability (n = 8). The results showed that the ß-AgVO3 samples showed lower counts of Candida albicans, Pseudomonas aeruginosa, and Streptococcus mutans due to their promising physicochemical properties. The mechanical properties were maintained with the addition of ß-AgVO3. The rGO samples showed higher counts of microorganisms due to the increase in physicochemical properties. It can be concluded that the incorporation of ß-AgVO3 into acrylic resins could be an alternative to improve the antimicrobial efficacy and performance of the material.

Effects of natural products-based dentifrices on acrylic resin for denture bases: A simulated period of 4 years.

PURPOSE: To evaluate the antimicrobial activity of dentifrices based on Malva sylvestris and propolis and the effect on the acrylic resin. METHODS: The inhibitory effect against Candida albicans, Enterococcus faecalis and Streptococcus mutans was determined. The specimens of resin were divided into groups: Control (brushing with distilled water); brushing with Colgate; brushing with Protex; brushing with Malvatricin, brushing with Proporalcare Dental Gel and brushing with Green Propolis Dental Gel. Brushing was carried out in a brushing machine. Roughness and color were assessed. The data were analyzed by ANOVA, followed by the Bonferroni post test (α= 0.05). RESULTS: The products evaluated showed antimicrobial activity against all microorganisms (P< 0.05), except Proporalcare Dental Gel, which was not effective against E. faecalis. Greater roughness (P< 0.05) was observed in the samples treated with Colgate. The samples from control and Protex groups showed the lowest color variation and the highest luminosity, with a difference in relation to the others (P< 0.05), which showed higher values, although clinically acceptable. CLINICAL SIGNIFICANCE: The dentifrices based on natural products can be indicated for cleaning prostheses, since they showed antimicrobial activity and did not cause perceptible color changes of the resin tested. The dentifrices did not produce adverse effects on the surface of the resin or did so less than the conventional dentifrice.

Incorporating versus coating antimicrobials for polymethyl methacrylate: A systematic review.

STATEMENT OF PROBLEM: Incorporating and coating with antimicrobials are techniques that can confer antimicrobial action on polymethyl methacrylate (PMMA) denture bases, which can accumulate microorganisms and promote oral and systemic disease. PURPOSE: The purpose of this systematic review was to answer the question: "Do techniques for incorporating and coating antimicrobial agents in PMMA promote antimicrobial action?" MATERIAL AND METHODS: The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist guidelines were followed, and the SCOPUS, PubMed/Medline, EMBASE, and Science Direct databases searched. The studies were selected in 2 stages, reading the titles and abstracts and then reading the selected studies in full. The risk of bias was analyzed by adapting the quasi-experimental studies tool by the Joanna Briggs Institute (JBI). RESULTS: A total of 970 articles were found in the databases; 71 were duplicates and, after reading the abstracts, 38 were selected for full reading. From these, 6 were excluded because they did not fulfill the inclusion criteria, and 32 studies were included in this review. Autopolymerizing, heat- polymerizing, and light-polymerizing resins were evaluated, with the incorporating technique prevailing over the coating, but both techniques effectively promoted antimicrobial activity. CONCLUSIONS: Incorporating and coating antimicrobial agents are effective methods of promoting antimicrobial activity in PMMA. Combining the 2 methods led to increased antimicrobial activity compared with each individually.

Effect of silver vanadate on the antibiofilm, adhesion and biocompatibility properties of denture adhesive.

Aim: To evaluate the biological and mechanical properties of an adhesive with nanostructured silver vanadate (AgVO3). Materials & methods: Specimens in poly(methyl methacrylate) (PMMA) were treated with Ultra Corega Cream (UCCA) denture adhesive with or without AgVO3. Biofilms of Candida albicans, Candida glabrata and Streptococcus mutans were grown and the viable cells counted. Fluorescence microscopy was used. The viability of the VERO cell and adhesive strength were evaluated. Results: All concentrations of AgVO3 reduced the biofilm formation and showed no cytotoxic effect. At 5 min and 24 h, UCCA with 5 and 10% AgVO3 showed better performance, respectively. Conclusion: AgVO3 promoted the antibiofilm activity of the adhesive, with a positive effect on the adhesive strength, and was biocompatible.

What is this summary about? Some people wear false teeth called dentures. They use a special glue to keep these false teeth in their mouths. It is important to clean dentures well and remove the glue every day. If the dentures get dirty, they can cause infections of the gums. Doctors and dentists can help, but sometimes medicines do not work well. This study checked to see whether adding a medicine that can kill bacteria into the glue could stop gum swelling and other illnesses, or make them better.What were the results? The glue containing the medicine killed microbes like fungi and bacteria. It also stuck things together well and was safe to use.What do the results mean? Using this special glue could help people with dentures to avoid illness.

Influence of post-processing on the adhesion of dual-species biofilm on polylactic acid obtained by additive manufacturing.

Introduction: Post-processing (PP) is performed to improve the surface, which can favor microbial adhesion and consequent pathological manifestations that impair the indication of polylactic acid (PLA) obtained by fused filament fabrication (FFF) for biomedical applications. This aims to evaluate the influence of chemical, thermal, and mechanical PP on the adhesion of Streptococcus mutants and Candida albicans, roughness, and wettability of the PLA obtained by FFF with and without thermal aging. Methods: The specimens were designed in the 3D modeling program and printed. The chemical PP was performed by immersion in chloroform, the thermal by the annealing method, and the mechanical by polishing. Thermal aging was performed by alternating the temperature from 5 °C to 55 °C with 5000 cycles. Colony-forming unit (CFU/mL) counting was performed on dual-species biofilm of C. albicans and S. mutans. Roughness was analyzed by rugosimeter and wettability by the sessile drop technique. Data were verified for normality using the Shapiro-Wilk test, two-way ANOVA (α = 0.05) applied for CFU and wettability, and Kruskal-Wallis (α = 0.05) for roughness. Results: Chemical, thermal, and mechanical PP methods showed no influence on CFU/mL of C. albicans (p = 0.296) and S. mutans (p = 0.055). Thermal aging did not influence microbial adhesion. Chemical PP had lower roughness, which had increased after aging. Wettability of the mechanical PP was lower. Conclusions: Post-processing techniques, do not present an influence on the adhesion of S. mutans and C. albicans in PLA obtained by FFF, chemical PP reduced roughness, and mechanical reduced wettability. Thermal aging did not alter the microbial adhesion and altered the roughness and wettability.

Silver vanadate nanomaterial incorporated into heat-cured resin and coating in printed resin - Antimicrobial activity in two multi-species biofilms and wettability.

OBJECTIVES: To incorporate the nanostructured silver vanadate decorated with silver nanoparticles (AgVO3) into denture base materials: heat-cured (HC) and 3D printed (3DP) resins, at concentrations of 2.5 %, 5 %, and 10 %; and to evaluate the antimicrobial activity in two multi-species biofilm: (1) Candida albicans, Candida glabrata, and Streptococcus mutans, (2) Candida albicans, Pseudomonas aeruginosa, and Staphylococcus aureus, and the wettability. METHODS: The AgVO3 was added to the HC powder, and printed samples were coated with 3DP with AgVO3 incorporated. After biofilm formation, the antimicrobial activity was evaluated by colony forming units per milliliter (CFU/mL), metabolic activity, and epifluorescence microscopy. Wettability was assessed by the contact angles with water and artificial saliva. RESULTS: In biofilm (1), HC-5 % and HC-10 % showed activity against S. mutans, HC-10 % against C. glabrata, and HC-10 % and 3DP-10 % had higher CFU/mL of C. albicans. 3DP-5 % had lower metabolic activity than the 3DP control. In biofilm (2), HC-10 % reduced S. aureus and P. aeruginosa, and HC-5 %, 3DP-2.5 %, and 3DP-5 % reduced S. aureus. 3DP incorporated with AgVO3, HC-5 %, and HC-10 % reduced biofilm (2) metabolic activity. 3DP-5 % and 3DP-10 % increased wettability with water and saliva. CONCLUSION: HC-10 % was effective against C. glabrata, S. mutans, P. aeruginosa, and S. aureus, and HC-5 % reduced S. mutans and S. aureus. For 3DP, 2.5 % and 5 % reduced S. aureus. The incorporation of AgVO3 into both resins reduced the metabolic activity of biofilms but had no effect on C. albicans. The wettability of the 3DP with water and saliva increased with the addition of AgVO3. CLINICAL SIGNIFICANCE: The incorporation of silver vanadate into the denture base materials provides antimicrobial efficacy and can prevent the aggravation of oral and systemic diseases. The incorporation of nanomaterials into printed resins is challenging and the coating is an alternative to obtain the inner denture base with antimicrobial effect.

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.

Artificial teeth obtained by additive manufacturing: Wear resistance aspects. A systematic review of in vitro studies.

Wear resistance is one of the properties that must be considered for maintaining the long-term functionality of artificial teeth in dental prostheses. This property can be altered by the method of tooth fabrication, the material, the chewing force, and the relationship to the antagonist tooth. This systematic review evaluated the wear resistance of artificial teeth obtained by the additive manufacturing method and aims to answer the question, "Do artificial teeth for dental prostheses obtained by additive manufacturing show wear resistance similar to prefabricated ones?" The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Checklist guidelines were followed with a customized search in Scopus, PubMed/Medline, Embase, Science Direct, and Google Scholar databases on August 30, 2023. The inclusion criteria were artificial teeth for dental prostheses in acrylic resin by additive manufacturing and comparing the wear resistance with conventional prefabricated teeth, in vitro and English studies, without time restriction. And excluded if 1) do not make artificial teeth by additive manufacturing or that were metal or ceramic teeth; 2) clinical trials, animal studies, review articles, case reports, letters to the editor, short communication, book chapters; 3) another language that is not English. The selection was in two steps, reading the titles and abstracts, followed by reading the selected studies in full. The risk of bias analysis was performed with the adaptation of the quasi-experimental studies tool by Joanna Briggs Institute. Four hundred and twelve articles were found in the databases, after the selection steps and application of eligibility criteria, 6 articles were included for qualitative data analysis and presented low risk of bias. For teeth obtained by additive manufacturing, 2 studies reported lower wear resistance, 2 studies had higher resistance, and 2 similar compared to prefabricated ones. Additive manufactured teeth compared to prefabricated teeth show influences on wear resistance due to differences in material composition, relationship to the antagonist's tooth, applied force, chewing cycles, and processing methods.

Denture stomatitis: Treatment with antimicrobial drugs or antifungal gels? A systematic review of clinical trials.

STATEMENT OF PROBLEM: Gel formulations containing antimicrobials are a potential alternative for the development of new medicines for the treatment of denture stomatitis (DS). However, whether they are more effective than antifungal drugs is unclear. PURPOSE: The purpose of this systematic review was to identify whether gels formulated with antimicrobial substances are more effective and biocompatible for the treatment of DS than antifungal drugs. MATERIAL AND METHODS: This systematic review was structured according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and registered in the International Prospective Register of Systematic Reviews (PROSPERO; CRD42022379510). Searches were performed in the PubMed, Lilacs, Web of Science, Scopus, Embase, and Google Scholar databases in November 2022. Randomized and nonrandomized clinical trials comparing the efficacy of experimental gels and conventional antifungals in the treatment of DS were included. RESULTS: Gels formulated with Zataria multiflora essential oil and clove and cinnamon extracts showed higher antimicrobial efficacy compared with miconazole and clotrimazole. Formulations containing Uncaria tomentosa, Punica granatum, and propolis extract showed similar efficacy to nystatin and miconazole. Two formulations containing P. granatum were less effective than nystatin and miconazole. Gels of Z. multiflora and miconazole induced adverse effects including burning, itching, nausea, and vomiting. The included studies did not evaluate the biocompatibility of the gels. CONCLUSIONS: Gels formulated with natural antimicrobials such as Z. multiflora, U. tomentosa, P. granatum, propolis, and clove and cinnamon showed higher or similar antimicrobial efficacy to conventional antifungals in the treatment of DS. The biocompatibility of experimental gels based on natural agents should be evaluated.

Hydroxyapatite coatings versus osseointegration in dental implants: A systematic review.

STATEMENT OF PROBLEM: Knowledge of the effectiveness of hydroxyapatite coatings on the surface of titanium dental implants is lacking because of difficulties in standardizing their thickness, roughness, and effect on osseointegration. The selection of articles describing this coating in osseointegration will be of great relevance to implant dentistry. PURPOSE: This systematic review aimed to answer the question, "How effective is hydroxyapatite on titanium surfaces for osseointegration?" MATERIAL AND METHODS: The Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) 2020 guidelines were followed, and the protocol was registered on the international prospective register of systematic reviews (PROSPERO) database (CRD42023422601). The PubMed, Scopus, Web of Science, and Embase databases were searched, and articles were selected manually in 2 steps by 2 blinded investigators according to the previously selected eligibility criteria. The risk of bias was assessed using the systematic review center for laboratory animal experimentation (SYRCLE) tool. RESULTS: Initially, 671 results were found. After analysis of eligibility criteria and full reading, 15 articles were included in the present review. Of these, 12 reported favorable osseointegration results for hydroxyapatite-coated surfaces, and 3 found no significant long-term difference between the coated and uncoated groups. CONCLUSIONS: Hydroxyapatite surface treatment is effective in the osseointegration of titanium dental implants because it favors the absorption of proteins, adhesion, and proliferation of bone cells when obtained by methods that ensure proper adhesion. (J Prosthet Dent xxxx;xxx:xxx-xxx).

Influence of dental implant/mini-implant design on stress distribution in overdentures: a systematic review.

PURPOSE: Critically evaluate the existing literature and answer the question, "Does the dental implant/mini-implant design influence the stress distribution in prosthetic overdentures according to finite element analysis?". METHODS: This systematic review was registered in the Open Science Framework (osf.io/2bquj) and followed the PRISMA protocols. The custom search strategy was applied to 4 databases. In vitro experimental studies that evaluated the influence of dental implant/mini-implant design on stress distribution in overdentures by FEM, without time and language restrictions, were included. The selection process was carried out in two stages by two reviewers independently. Risk of bias analysis was performed by a checklist of important parameters. RESULTS: Sixty articles were evaluated by their title and abstract, four were selected for full reading, three were relevant, and nine were included by additional search. The 12 studies have a low risk of bias. The meta-analysis could not be performed due to the heterogeneity of the data (implant type, design variation, load intensity, and direction). CONCLUSION: It can be inferred from the evaluated literature that design modifications influence the stress distribution, but as the FEM presents limitations inherent to the in vitro study, clinical trials are necessary to infer the effectiveness of the modifications. It should be noted that there is no consensus on which is the best thread design and that implants with a very narrow diameter are subject to the highest stress concentration.

Osseointegration, antimicrobial capacity and cytotoxicity of implant materials coated with graphene compounds: A systematic review.

The use of graphecs excellent mechanical properties. However, it is necessary to evaluate the biological effects of this material. This systematic review aimed to observe and understand through studies the current state of the art regarding osseointegration, antimicrobial capacity, and the cytotoxicity of graphene coating applied to the surface of dental implant materials. Searches in PubMed, Embase, Science Direct, Web of Science, and Google Scholar databases were conducted between June and July 2021 and updated in May 2022 using the keywords: graphene, graphene oxide, dental implants, zirconium, titanium, peek, aluminum, disilicate, methyl-methacrylate, cytotoxicity, osseointegration, and bone regeneration. The criteria included in vivo and in vitro studies that evaluated antimicrobial capacity and/or osseointegration and/or cytotoxicity of dental implant materials coated with graphene compounds. The risk of bias for in vitro studies was assessed by the JBI tool, and for in vivo studies, Syrcle's risk of bias tool for animal studies was used. The database search resulted in 176 articles. Of the 18 articles selected for full reading, 16 remained in this systematic review. The use of graphene compounds as coatings on the surface of implant materials is promising because it promotes osseointegration and has antimicrobial capacity. However, further studies are needed to ensure its cytotoxic potential.

Antibacterial activity of barbatimão (Stryphnodendron adstringens) against periodontopathogens and cytotoxic effects on fibroblasts.

This in vitro study aimed to evaluate the growth-inhibitory effects against periodontal disease-causing bacteria and cytotoxic effects against mouse fibroblast cells of the Stryphnodendron adstringens (barbatimão) hydroalcoholic extract. The contents of phenols and tannins in the extract were determined. The growth-inhibitory activity of the barbatimão was evaluated by determining the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). The viability of fibroblast cells was analyzed using the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl-tetrazolium bromide assay at 24 and 48 h post-treatment. The MIC values of the extract against Prevotella intermedia, Porphyromonas gingivalis, and Fusobacterium nucleatum were 0.05, 0.125, and 2 mg mL-1, respectively, while the MBC values were 4, 2, and 2 mg mL-1, respectively. The viability rate of barbatimão (0.25 mg mL-1)-treated L929 cells was higher than that of chlorhexidine (0.12%)-treated L929 cells at 48 h post-treatment. The contents of total phenolics and total tannins in the extract were 837.39 ± 0.10 and 785.82 ± 0.14 mg of tannic acid equivalent per gram of the extract, respectively. These findings indicate that the barbatimão hydroalcoholic extract, which exerted potent growth-inhibitory effects against the test microbial species and low cytotoxic effects on fibroblasts, has potential applications in the development of novel mouthwash products.

Graphene loaded into dental polymers as reinforcement of mechanical properties: A systematic review.

Graphene compounds are incorporated into polymers in order to improve their mechanical properties and in dentistry this modification favors the clinical performance of these materials. The aim of this review was to evaluate graphene compounds, their concentrations, and their effect on mechanical properties as flexural, tensile, and compressive strength and hardness of polymethylmethacrylate (PMMA) and polyether-ether-ketone (PEEK) for dental application. The search was carried out in two steps in PubMed/Medline, Embase, Scopus, and Web of Science databases. The eligibility criteria included studies that incorporated pure graphene compounds into dental polymers and evaluated their mechanical properties. Were found 4984 results, of which 11 articles were included in this review. Graphene compounds: graphene oxide (GO), reduced graphene oxide (rGO), and graphene nanoplatelets (GNP) were incorporated into PMMA and PEEK, in concentrations ranging from 0.1 to 10 wt%. Concentrations lower than 0.75 wt% of GO in PMMA and 1 wt% of GNP in PEEK resulted in increased flexural, tensile, compression strength, and hardness of these polymers. It was concluded that the incorporation of graphene compounds in low concentrations increases dental polymers' mechanical properties.