Does aPDT reduce bacterial load in endodontic infected teeth? A systematic review and meta-analysis.

This systematic review investigated whether antimicrobial photodynamic therapy (aPDT) after chemomechanical root canal disinfection (CD) yields a greater microbial load reduction than only CD. An electronic literature search was conducted on four databases up to November 2022, with no language or publication date restrictions. Randomized and non-randomized clinical trials were included if participants had a primary endodontic infection in permanent teeth, and if microbial loads before and after using aPDT were compared. Two researchers independently screened titles and abstracts to determine study eligibility. Assessments included risk of bias and methodological quality. This review was registered in PROSPERO (CRD42020181783). Eight studies were included in the qualitative analysis, and six were eligible for meta-analysis. In the random effects model, aPDT significantly improved the results of root canal disinfection when compared with standard protocols for cleaning and shaping (p = 0.04, 95% CI -1.72, -0.05). Subgroup analysis suggested that aPDT has a better effect on reducing the load of anaerobic microorganisms (p = 0.003, 95% CI -3.36, -0.69). The use of aPDT as an adjunct to chemomechanical disinfection promotes additional reduction of the microbial load and, therefore, seems to improve the results of root canal treatments in permanent teeth with a primary endodontic infection. However, certainty of evidence should be improved.

Full analysis of the effects of modeler liquids on the properties of direct resin-based composites: a meta-analysis review of in vitro studies.

OBJECTIVES: This study systematically revised the literature to answer the following question: do modeler liquids (MLs) affect the properties of direct resin-based composites (RBCs)? MATERIALS AND METHODS: The review followed the PRISMA statement, and the search was conducted in PubMed, Scopus, Web of Science, Embase, and Lilacs databases. Studies were included if they investigated the properties of RBCs prepared using the restorative dental modeling insertion technique (RDMIT). The risk of bias was performed with the RoBDEMAT tool. Statistical analyses were conducted using Review Manager, and heterogeneity was assessed with the Cochran Q test and I2 statistics. RESULTS: From 309 studies identified, 25 met the eligibility criteria, and 23 were meta-analyzed. In total, 27 MLs and 23 RBCs were evaluated. Modeled and non-modeled RBCs showed similar results in terms of cohesive strength, flexural strength, load-to-fracture, modulus of elasticity, work of fracture, degree of conversion, solubility, weight change, microhardness, and color change. Sorption and roughness benefited from the use of MLs, whereas translucency and whitening index were more adequate in the non-modeled RBCs. Aging affected similarly the modeled and non-modeled RBCs. Most studies showed a moderate risk of bias. CONCLUSIONS: Modeled and non-modeled RBCs performed similarly in most of the properties, and the use of non-solvated lubricants offered beneficial effects in some cases. CLINICAL RELEVANCE: When a balance has to be made between the RDMIT and the conventional technique, our review supports the safe application of modeler liquids for the handling of composite increments during the sculpting fabrication of direct resin-based restorations.

Does the liner material influence pulpal vitality in deep carious cavities submitted to selective caries removal? A network meta-analysis review.

OBJECTIVES: To evaluate whether the restorative material in direct contact with the dentin influences pulp vitality in primary and permanent teeth with deep carious lesions restored after selective caries removal (SCR). MATERIAL AND METHODS: Systematic searches of databases MEDLINE via PubMed, Scopus and ISI Web of Science were performed for primary and permanent teeth. Inclusion criteria were applied for title and abstract reading of databases search results. After full texts review of included studies, those that did not meet exclusion criteria were excluded from meta-analysis. RESULTS: For meta-analysis, 2 studies were included for permanent teeth and 6 for primary teeth. The failure events reported were meta-analyzed using two statistical methods: standard pairwise meta-analysis (SPMA) and network meta-analysis (NMA). The SPMA identified similar failure occurrence of restorations performed with calcium hydroxide (CH) and other liner materials (RR 0.84, 95% CI 0.41, 1.74; p = 0.64), no significant difference between the use of alternative liners or CH regardless deciduous or permanent teeth (RR 0.79, 95% CI 0.36, 1.71; p = 0.55) and similar risk of failing at different follow-ups for all liner materials tested (RR 0.77, 95% CI 0.35, 1.70; p = 0.52). Probabilistic analysis indicated GIC as liner material with the highest probability of clinical success (SUCRA = 72.76%), and CH ranked as the worst liner material (SUCRA = 21.81%). CONCLUSION: Pulpal vitality was not affected by material used as liner after selective caries removal in deep carious cavities. CLINICAL RELEVANCE: Current clinical evidence supports the weak recommendation to not use calcium hydroxide as liner after SCR.

Distribution of anxiety and depression among different subtypes of temporomandibular disorder: A systematic review and meta-analysis.

BACKGROUND: The evidence on the relationship between anxiety and depression and patients with distinct subtypes of temporomandibular disorder (TMD) is uncertain, so a thorough review study on the topic is still missing. OBJECTIVES: This systematic review investigated the distribution and severity of anxiety and depression in patients diagnosed with different subtypes of TMD. METHODS: The study is registered in PROSPERO (CRD42020150562) and it followed the PRISMA 2020 Statement. We searched in PubMed, Web of Science, Scopus and SciELO databases (last search: 12 March 2021) and the reference list from the included studies. Study eligibility criteria consisted of: (i) patients diagnosed with TMD using the Research Diagnostic Criteria (RDC/TMD) or Diagnostic Criteria (DC/TMD) instruments; (ii) assessment of anxiety and/or depression with validated psychological instruments and (iii) allocation of patients into a minimum of two distinct TMD subtypes with at least one group having myofascial pain (comparison group). Analyses were carried out using RevMan 5.3.5 statistical package and random- or fixed-effects models (α = 0.05). The quality of evidence was assessed based on review authors' judgment derived from a 10-item appraisal tool for prevalence studies and with the Newcastle-Ottawa scale. RESULTS: Of the 4086 records identified in total, 24 were eligible for inclusion; meta-analyses were conducted with 20 studies. In total, 3678 subjects were included in the review. Most of the studies found that patients with myofascial pain showed similar occurrence and severity of anxiety/depression as compared to other subtypes of TMD, although the average prevalence seemed to be higher among the diagnoses consisting of myofascial pain (muscular TMD). Despite the moderate-to-high heterogeneity, anxiety and depression were more frequently distributed within patients with myofascial pain (p = .001). TMD patients without myofascial pain presented less severe levels of anxiety and depression than patients with only myofascial pain (p ≤ .01). The type of psychological instrument seems to affect the assessment of both anxiety and depression emotional states. CONCLUSION: The findings of this review suggest that patients with myofascial pain are more anxious and more depressed than patients with other subtypes of TMD. IMPLICATIONS: Considering that anxiety and depression are differently distributed within the TMD population, a proper assessment of the psychological state of patients seems essential to offer an adequate treatment and management of each specific subtype of TMD.

Replacing HEMA with alternative dimethacrylates in dental adhesive systems: evaluation of polymerization kinetics and physicochemical properties.

PURPOSE: To evaluate the mechanical and physical properties of experimental HEMA-containing and HEMA-free resin adhesives. MATERIALS AND METHODS: Experimental HEMA-free adhesives containing alternative dimethacrylates (bis-EMA 10 [B10], bis-EMA 30 [B30], PEG 400 [P400], PEG 1000 [P1000], PEG 400 UDMA [UP400]) were formulated and compared with a HEMA-containing adhesive (control). The adhesives were characterized by rheological analysis, polymerization kinetics (PK), water sorption (WS), and solubility (SL) tests. Flexural strength (FS) and flexural modulus (E) tests were performed under dry or wet conditions (distilled water or 70% ethanol solution). One-way and two-way ANOVA as well as Tukey's test were used to evaluate differences between groups (p < 0.05). RESULTS: The control group showed the lowest viscosity and was the only one with a degree of conversion lower than 50%. The control and the P1000 adhesive showed the statistically significantly highest WS (p < 0.05). The control and the UP400 adhesive showed the highest FS and E, and the dry-stored specimens showed more improved mechanical strength than did the wet-stored specimens (p < 0.05). CONCLUSION: The physicomechanical properties of some of the HEMA-free adhesives were substantially improved when compared with those of the control, indicating that they could be potential monomers for the development of HEMA-free adhesive systems.

Is Cention-N comparable to other direct dental restorative materials? A systematic review with network meta-analysis of in vitro studies.

OBJECTIVES: To compare the performance of Cention-N® with direct restorative materials used at the daily practice (e.g., resin-based composites/RBC, glass ionomer cements/GIC, bioactive resins, silver amalgam) via a systematic review study. METHODS: The review followed the PRISMA-NMA recommendations, and the protocol of the review was published at osf.io/ybde8. The search was conducted in PubMed/MEDLINE, Scopus, Web of Science, Embase, Lilacs, and SciELO databases, as well as in the grey literature (Open Grey, Proquest, and Periódicos CAPES). Studies with an in vitro experimental design evaluating the characteristics and properties of Cention-N in comparison to other restorative materials were included. The risk of bias of included studies was assessed using the RoBDEMAT tool, and meta-analyses were conducted using Review Manager 5.4 and MetaInsight V3 tools. RESULTS: A total of 85 studies were included in the review, from which 79 were meta-analyzed. Several characteristics of direct restorative materials were analyzed, including physical (color change, degree of conversion, hardness, microleakage, polymerization rate, roughness, water solubility, water sorption), mechanical (bond strength to dentin, compressive strength, diametral tensile strength, flexural modulus, flexural strength, load-to-fracture, wear), and biological (alkalinizing effect, antibacterial activity, calcium and fluoride release) properties. SIGNIFICANCE: Cention-N presented similar physico-mechanical properties compared to RBCs, but a stronger behavior than GICs. Despite the Alkasite nature of Cention-N, GICs may still demonstrate the greatest fluoride releasing ability from all direct restorative materials. This review confirmed the adequate behavior of Cention-N when compared to several other more traditionally used materials, confirming its applicability for the permanent restoration of decayed or fractured teeth.

Postoperative pain after single-visit root canal treatment or vital pulp therapy: A systematic review and meta-analysis.

BACKGROUND: This systematic review aimed to investigate whether vital pulp therapy and root canal treatment (RCT) promote different postoperative pain. STUDIES REVIEWED: The authors searched PubMed, Cochrane Library, Embase, and Latin American and Caribbean Health Sciences Literature databases for studies published through June 30, 2022. The authors included randomized clinical trials if they reported on the assessment of postoperative pain after direct pulp capping, partial pulpotomy, pulpotomy, or single-visit RCT. The authors assessed the frequency of no, mild, moderate, and severe postoperative pain. They conducted meta-analyses to compare postoperative pain after full pulpotomy (PULP) and RCT. RESULTS: The qualitative synthesis included 57 studies, and the authors conducted meta-analysis of 3. PULP leads to more asymptomatic cases (relative risk [RR], 1.06; 95% CI, 1.01 to 1.11; P < .01; I2 = 67%) and to a lower occurrence of mild (RR, 0.89; 95% CI, 0.79 to 0.99; P < .04; I2 = 37%) and moderate (RR, 0.70; 95% CI, 0.51 to 0.95; P < .02; I2 = 57%) postoperative pain than RCT. The frequency of severe pain was very low for both vital pulp therapy and RCT. Moderate to severe postoperative pain was more common at 48 hours through 72 hours after RCT and up to 36 hours after PULP. Pain intensity after PULP was higher using calcium-enriched material compared with using mineral trioxide aggregate at 12, 18, and 36 hours (P < .001). PRACTICAL IMPLICATIONS: PULP showed a significantly higher incidence of no pain and a lower incidence of mild and moderate pain than single-visit RCT. Clinical decisions for RCT or PULP should not be based on differences in postoperative pain. When analgesia is indicated, it probably should be limited to a short time after PULP.

Analysis of Tissue Repair of a New Cement Based on Calcium and Strontium Aluminates: A Triple-Blinded, Randomized, Controlled Trial in an Animal Model.

OBJECTIVE: The focus of this triple-blind randomized study was to evaluate the biocompatibility of a new root canal filling sealer (RCFS) based on tristrontium aluminate and dodecacalcium hepta-aluminate in living tissue. MATERIAL AND METHODS: Forty-five Wistar rats (Rattus norvegicus) were divided into three groups: control (polyethylene), sealer (Bio-C Sealer, Londrina, PR, Brazil), and experimental (tristrontium aluminate and dodecacalcium hepta-aluminate). The tissues were analyzed under an optical microscope to assess different cellular events at different time intervals (7, 15, and 30 days). STATISTICAL ANALYSIS: Data were analyzed using the Kruskal-Wallis and Dunn (p < 0.05) tests. RESULTS: In the initial period, a moderate inflammatory infiltrate was observed, similar between the endodontic cements groups (p = 0.725). The intensity of the infiltrate decreased with time, with no significant difference among the groups (p > 0.05). The number of young fibroblasts was elevated in all groups evaluated at 7 days. The experimental group showed the highest number of cells at all time intervals, but the difference with the sealer group at 7 (p = 0.001) and 15 days (p = 0.002) and the control group at 30 days was not significant (p = 0.001). Regarding tissue repair events, the amount of collagen fibers increased over the experimental intervals, with no significant difference between the sealer and control groups (p > 0.05). CONCLUSION: The experimental RCFS based on calcium and strontium aluminates proved to be biocompatible for use in close contact with periapical tissue, inducing a low inflammatory reaction and favoring rapid tissue repair.

Effects of long-term water storage on the microtensile bond strength of five experimental self-etching adhesives based on surfactants rather than HEMA.

OBJECTIVES: The purpose of this study is to evaluate the hypothesis that replacing 2-hydroxyethyl methacrylate (HEMA) for surfactant dimethacrylates (SD) does not affect the immediate and long-term microtensile bond strength (µTBS) of experimental two-step self-etch HEMA-free adhesive systems applied on dentin. MATERIALS AND METHODS: Five experimental HEMA-free two-step self-etching systems containing different SD (ethoxylated bisphenol A diglycidyl dimethacrylate (Bis-EMA 10, B10), Bis-EMA 30 (B30), poly-ethyleneglycol (400) dimethacrylate (PEG 400, P400), PEG 1000 (P1000), and PEG 400 urethane dimethacrylate (UDMA) (UP400)) and a HEMA-containing system (control) (HA) were formulated. Specimens were subjected to the µTBS test after 24 h and 6 and 12 months of storage. Data (in megapascals) were analyzed by Kruskal-Wallis and Dunn tests (α = 0.05). RESULTS: Medians of the µTBS data after 24 h of storage are: HA = 57.2(A), B10 = 26.2(BC), B30 = 24.0(C), P400 = 32.6(BC), P1000 = 37.3(B), and UP400 = 57.9(A); after 6 months are: HA = 47.9(A), B10 = 18.5(B), B30 = 7.8(C), P400 = 16.1(B), P1000 = 14.6(BC), and UP400 = 51.6(A); and after 12 months are: HA = 31.2(A), B10 = 15.2(B), B30 = 9.0(B), P400 = 9.1(B), P1000 = 13.3(B), and UP400 = 35.7(A). Between the HEMA-free groups, the adhesive system formulated with PEG 400 UDMA produced similar µTBS to the HEMA-containing group. Also, the storage of specimens decreased the µTBS (p < 0.05). CONCLUSION: Replacing HEMA for PEG 400 UDMA in an adhesive system formulation generated a satisfactory µTBS to dentin. CLINICAL RELEVANCE: Surfactant dimethacrylates have a potential use in the development of HEMA-free self-etching adhesive systems, which are more chemically stable.

Preparation and characterization of NaF/Chitosan supramolecular complex and their effects on prevention of enamel demineralization.

Fluoridated mouthrinse is indicated for individuals with high risk of caries. Chitosan (Chit) exhibits antibacterial properties, but little is known about its effects on enamel when combined with sodium fluoride (NaF) to form NaF/Chit supramolecular complexes. In our study, NaF/Chit supramolecular complexes structured as microparticles were synthetized and characterized, and their effects on human enamel were evaluated after cariogenic challenge simulating the daily mouthrinse use. Initially, NaF/Chit complex formation was investigated based on several titrations by measuring the zeta potential, electrical conductivity (κ), hydrodynamic diameter (Dh), viscosity (η) and heat flow (by isothermal titration calorimetry) against the molar ratio [NaF]/[Chitmonomer], which allowed us to identify the interactions between Chit-NaF with a stoichiometry of approximately 0.68. Spontaneous microparticle formation was observed. Samples of enamel blocks were prepared and divided into eight groups (n = 10/group): (i) 0.2% Chit; (ii) 0.2% NaF; (iii) 0.2% NaF/Chit suspension; (iv) 0.2% acetic acid; (v) 0.05% Chit; (vi) 0.05% NaF; (vii) 0.05% NaF/Chit suspension; and (viii) 0.05% acetic acid. Cariogenic challenge was performed in each sample by cycling in demineralization and remineralization solutions for 7 days. Before each demineralization cycle, the corresponding substances were passively applied daily for 90 s, even in groups with 0.02% concentration. After 7 days, samples were examined for Knoop hardness (KHN) measurements. The data were analyzed by repeated-measures ANOVA and Tukey tests (α = 0.05). The 0.2% NaF and 0.2% NaF/Chit groups showed higher KHNpost-challenge values than the other groups. The 0.2% NaF/Chit microparticle suspension reduced the enamel hardness loss after cariogenic challenge as effectively as the 0.2% NaF solution and demonstrated potential for use in a formulation with anti-caries effects.

Correlation between surface roughness and microhardness of experimental composites with varying filler concentration.

AIM: The purpose of this study was to investigate the influence of the surface roughness on the surface microhardness of experimental composites with varying filler concentration. MATERIALS AND METHODS: Experimental resin composites were formulated by mixing Bis-GMA and TEGDMA in a 50/50% weight ratio and CQ/EDAB were added to make the material photosensitive. Silanized glass particles were incorporated in the resin blend in two concentrations: C50 with 50% and C75 with 75% in weight ratio. The surface roughness and the surface microhardness measurements were determined after every three finishing procedures with #280-, #600- and #1200-grit wet sandpapers, respectively. The data were analyzed statistically by Two Way ANOVA and Tukey's test, and comparisons were conducted using the Spearman's correlation test (p > 0.05). RESULTS: The surface roughness and surface microhardness were negatively associated (r = - 0.68) and the finishing procedures of both composites resulted in harder and smoother surfaces than the initial ones. Additionally, in a smooth circumstance, the higher content of fillers has not resulted in a composite with better microhardness and smoothness. CONCLUSION: Finishing procedures decreased the surface roughness and consequently improved the surface microhardness of the composites evaluated. CLINICAL SIGNIFICANCE: Finishing and polishing procedures are effectives in reducing the surface roughness amplitude of composite materials and in improving their surface microhardness. Thus a microhardness test and any hardness evaluation must be conducted only after a properly finished and polished surface is achieved.

Which self-etch acidic composition may result in higher dental bonds at the long-term? A network meta-analysis review of in vitro studies.

OBJECTIVES: This review evaluated the effects of the acidic composition of self-etch (SE) adhesives at the long-term bond strengths to dentin and enamel. DATA: The review followed the PRISMA Extension Statement for network meta-analysis. Studies were identified by a systematic search in PubMed, Web of Science, and Scopus databases. STUDY SELECTION: The inclusion criteria were in vitro studies that evaluated bond strength data of samples analyzed at both immediate and long-term (after aging simulation) periods and that were bonded to sound dentin/enamel using SE adhesives, with at least one group of adhesives being based on 10-MDP (10-methacryloyloxy-decyl-dihydrogen-phosphate; control) and the other group being comprised of alternative acidic monomers. Statistical analyses were conducted using two methods: standard pairwise meta-analysis (SPMA) and Bayesian network meta-analysis (NMA). Heterogeneity was assessed by using the Cochran Q test and I2 statistics. RESULTS: From 5220 studies identified, 87 met the eligibility criteria and 83 were meta-analyzed. Seventeen adhesives were based on 10-MDP and 44 systems were based on alternative acids. The resin-dentin/enamel bonds were predominantly reduced after aging (∼84% of cases). From the SPMA findings, the following acidic compositions showed lower bond strength values (effect size: mean difference [MD] with 95% confidence interval [95% CI]) than 10-MDP: 4-META (MD -4.99, 95% CI: -7.21, -2.78; p<0.001); sulfonic acids (MD -9.59, 95% CI -12.19, -6.98; p<0.001); unspecified phosphate esters (MD -8.89, 95% CI -17.50, -0.28; p = 0.04); or mixed acids (MD -11.0, 95% CI -13.62, -8.38; p<0.001). The dental bonds were benefited from the presence of 10-MDP upon longer aging (>6 months). From the NMA probabilistic findings, adhesives based on 10-MDP and phosphonic acids ranked as having the best and the worst bonding potential to dentin, respectively. More than one composition (phosphonic acids and mixed acids) ranked similarly to 10-MDP in enamel. The studies scored as having moderate risk of bias (58.6%), followed by low (39.1%) and high (2.3%) risk of bias. CONCLUSION: 10-MDP is an outstanding acidic monomer that contributes to higher bonds to dentin at the long-term. In enamel, there is no evidence that one acidic composition prevails over the other. CLINICAL SIGNIFICANCE: The acidic composition of SE adhesives affects the resistance of dental bonds after simulated aging, with 10-MDP playing a significant role in the adhesion to dentin but not to the enamel. REGISTRATION NUMBER: This report is registered at the Open Science Framework (osf.io/urtdf).

Is the presence of 10-MDP associated to higher bonding performance for self-etching adhesive systems? A meta-analysis of in vitro studies.

OBJECTIVE: The purpose of this systematic review and meta-analysis was to analyze the literature on the bond strength of self-etching (SE) adhesives containing 10-MDP or other acidic functional monomers, comparing the bonding performance of both compositions. METHODS: This study is registered in PROSPERO (CRD42020175715) and it followed the PRISMA Statement. The literature search was performed in PubMed, Web of Science, SciELO, Scopus, LILACS, IBECS, and BBO from the starting coverage date through 30 June 2021. Study eligibility criteria consisted of in vitro studies that evaluated the bond strength (microtensile, microshear, tensile or shear testing) to sound dentin/enamel of a minimum of two distinct SE systems, with at least one material containing 10-MDP and one other being comprised of a distinct acidic composition. Statistical analyses were carried out with RevMan 5.3.5 and using random-effects models with the significance level at p < 0.05. Also, Bayesian network meta-analysis (NMA) was conducted using MetaInsight V3 tool. RESULTS: From 740 relevant studies evaluated in full-text analysis, 210 were incorporated to the systematic review and 206 in meta-analysis. The majority of studies was classified as having medium risk of bias (56.7%), followed by low (35.2%) and high (8.1%) risk of bias. Data from a total of 64 adhesive systems were collected, which favored the 10-MDP-based group at both dentin (overall effect: 6.98; 95% CI: 5.61, 8.36; p < 0.00001) and enamel (overall effect: 2.79; 95% CI: 1.62, 3.96; p < 0.00001) substrates. Microtensile testing was more frequently used (73.4%) in the included studies. Adhesives based on 10-MDP showed greater bonding performance than adhesives comprised of monomers such as PENTA, 6-MHP, 4-META, 4-MET, pyrophosphate esters, mixed composition or monomers derived from sulfonic acid (p ≤ 0.01); whereas similar bond strength values were verified between 10-MDP-based materials and those containing PEM-F, acrylamide phosphates, 4-AET, MAC-10, or monomers derived from polyacrylic and phosphonic acids (p ≥ 0.05). Adhesives based on GPDM were the only ones that resulted in greater bonding potential than the 10-MDP-based group (p = 0.03). Dental bonds in dentin were favored with the application of 2-step 10-MDP-based adhesives; whereas in enamel the dental bonds were favored for both 2-steps versions of adhesives, regardless of the presence of 10-MDP. Indirect evidence from NMA revealed that 1-step 10-MDP-free and universal 10-MDP-free adhesives seemed to perform worst in dentin and enamel, respectively. SIGNIFICANCE: Adhesives containing 10-MDP showed higher bonding performance than materials formulated with other acidic ingredients, although this result relied on the type of mechanical testing, type of the substrate, acidic composition of the adhesive, and the application category of the SE system. This review summarized the effects of the foregoing factors on the adhesion to dental substrates.

Tooth- and Patient-Related Conditions May Influence Root Canal Treatment Indication.

AIM: To investigate predisposing aspects related to the indication for root canal treatment (RCT) at Dental Schools of Brazil. METHODS: Data of 207 patients referred to endodontic treatment at undergraduate Dental Schools of Brazil were collected over a period of 8 months. Patient-related data included age, gender, first dental visit, tooth brushing frequency, number of remaining teeth, and previous endodontic treatment, and tooth-related information regarding number, type, and location in the mouth of teeth that need RCT, waiting time for the endodontic treatment, endodontic diagnosis, pain report, and dental crown condition was collected for each participant. Bivariate analysis (Chi-square test; p < 0.05) associated gender and tooth/patient-related conditions. Poisson regression analysis compared multiple endodontic need and exposure variables. RESULTS: Patients were mainly comprised of women (65.2%), aged 18-39 years (69.6%). Previous RCT was significantly more prevalent in women when compared to men (p=0.005). First dental visit at later moment (after 20 years of age) demonstrated 400% greater prevalence of multiple RCT demand when compared to patients that attended the dental office at age below seven years (p=0.032). Most of the patients presented only one tooth needing RCT (80.2%), mainly premolars (44.9%). Interestingly, women underwent more RCT in maxillary teeth (p=0.016) and significantly contributed with their report to the diagnosis process when compared to men (p=0.014). Regarding dental crown condition, 45.4% of all teeth registered unsatisfactory restorations, which were more pronounced in female patients (p=0.018). Unsatisfactory restorations or dental caries had 75% and 82%, respectively, less prevalence of multiple RCT indication when compared to sound dental crown (p=0.001). CONCLUSIONS: RCT was undertaken more frequently in young female adults' premolars presenting unsatisfactory restorations. First dental visit, number of teeth with previous endodontic treatment, tooth group, and dental crown condition were significantly associated with the necessity of multiple endodontic treatments.

Synthesis of a chitosan nanoparticle suspension and its protective effects against enamel demineralization after an in vitro cariogenic challenge.

OBJECTIVE: Our study aims to synthesize, characterize, and determine the effects of a ChNPs suspension on human enamel after cariogenic challenge via pH-cycling. METHODOLOGY: ChNPs were synthesized by ion gelation and characterized by Transmission Electron Microscopy (TEM) and Dynamic Light Scattering. Forty enamel blocks were divided into four groups (n=10/group): (i) ChNPs suspension; (ii) chitosan solution; (iii) 0.05% sodium fluoride (NaF) solution; and (iv) distilled water. Specimens were exposed to cariogenic challenge by cycling in demineralization solution (3 h) and then remineralized (21h) for 7 days. Before each demineralization cycle, the corresponding solutions were passively applied for 90 s. After 7 days, specimens were examined for surface roughness (Ra) and Knoop hardness (KHN) before and after the cariogenic challenge; % KHN change (variation between initial and final hardness), and surface topography by an optical profilometer. The data were analyzed by repeated-measures ANOVA, One-way ANOVA, and Tukey tests (α=0.05). RESULTS: TEM images showed small spherical particles with diameter and zeta potential values of 79.3 nm and +47.9 mV, respectively. After the challenge, all groups showed an increase in Ra and a decrease in KHN values. Optical profilometry indicated that ChNPs- and NaF-treated specimens showed uneven roughness interspersed with smooth areas and the lowest %KHN values. CONCLUSION: The ChNPs suspension was successfully synthesized and minimized human enamel demineralization after a cariogenic challenge, showing an interesting potential for use as an oral formulation for caries prevention.

Which materials would account for a better mechanical behavior for direct endocrown restorations?

PURPOSE: To investigate the mechanical performance and fracture behavior of endocrown restorations prepared using different composite materials and following a direct technique. METHODS: Sound molars were cut at 2 mm above the cementoenamel junction, endodontically treated, and allocated according to the type of restoration (n = 7): without post (endocrowns) or with post (post-retained restorations). Endocrowns were fabricated with conventional composite (Filtek Z350); bulk fill composite (Filtek Bulk Fill); conventional composite modeled using resin adhesives (SBMP: Scotchbond Multipurpose Adhesive; or SBU: Scotchbond Universal Adhesive); and lithium disilicate ceramic (E.max; Positive control). The post-retained restorations were fabricated with glass-fiber post combined with conventional or bulk fill composites. All restorations were bonded following an etch-and-rise adhesive approach or self-adhesive resin cement. The teeth were submitted to fatigue (Byocycle) and compression (EMIC DL500) testing at a crosshead speed of 1 mm/min. Data were analyzed with ANOVA and Tukey (p < 0.05) and Weibull analysis was carried out in order to evaluate the reliability of restorations. RESULTS: The bulk-fill-based endocrown showed a stronger performance than the control. The presence of SBMP or the use of bulk-fill composite resulted in the occurrence of less aggressive fractures than the other restorative systems. Endocrowns bonded directly to the tooth seemed to produce similar fracture strength properties as compared to endocrowns bonded using self-adhesive resin cementation. The bulk-fill-based endocrown showed the greatest reliability of study. CONCLUSION: Resin-based restorative materials seem to be interesting alternative options to fabricate large dental restorations in lieu of the more traditionally used glass ceramics or root canal post systems.

Antimicrobial, mechanical and biocompatibility analysis of chlorhexidine digluconate-modified cements.

BACKGROUND: The focus of this study was to evaluate the antimicrobial, mechanical properties and biocompatibility of glass ionomer (GICs) modified by Chlorhexidine (CHX). MATERIAL AND METHODS: For biocompatibility, 105 male Wistar rats were used, divided into 7 groups (n=15): Group C (Control,Polyethylene), Groups M, M10, M18, and Groups RL, RL10, RL18 (M-Meron and RL-Riva Luting: conventional, and modified with 10%, and 18% CHX, respectively). The tissues were analyzed under optical microscope for different cellular events and time intervals. Antibacterial effect and Shear Bond Strength Test (SBST) were also analyzed. Biocompatibility was analyzed by the Kruskal-Wallis and Dunn tests; SBST one-way ANOVA and Tukey test (P<0.05). For the antibacterial effect, the Kruskal-Wallis and Friedman, followed by Dunn (P<0.05) tests were used. RESULTS: Morphological study of the tissues showed inflammatory infiltrate with significant differences between Groups C and RL18, in the time intervals of 7(P=0.013) and 15(P=0.032) days. The antimicrobial effects of the cements was shown to be CHX concentration-dependent (P=0.001). The SBST showed no significant difference between the Groups of Meron cement (P=0.385), however, there was difference between Group RL and Groups RL10 and RL18 (P=0.001). CONCLUSIONS: The addition of CHX did not negatively influence the SBST. Meron-CHX-10% was the most biocompatible, and Riva-CHX-18% had more influence on the inflammatory process and presented slower tissue repair. Key words:Glass ionomer, chlorhexidine, biocompatibility, antimicrobial properties, microscope.

In Vivo Biocompatibility, Mechanical, and Antibacterial Properties of Cements Modified with Propolis in Different Concentrations.

OBJECTIVES: The focus of this triple-blind randomized study was to evaluate the mechanical properties, antibacterial effect, and in vivo biocompatibility of glass ionomer cements (GICs) modified with ethanolic extracts of propolis (EEP). MATERIALS AND METHODS: For biocompatibility tests, 135 male Wistar rats were used and divided into nine groups: Group C (control, polyethylene), Groups M, M10, M25, M50 (Meron; conventional, and modified with 10%, 25%, 50% EEP, respectively), Groups KC, KC10, KC25, KC50 (Ketac Cem; conventional, and modified with 10%, 25%, 50% EEP, respectively). The tissues were analyzed under an optical microscope for different cellular events in different time intervals. Shear bond strength test (SBST) on cementation of metal matrices (n = 10, per group), adhesive remnant index (ARI) in bovine incisors (n = 10, per group), and antibacterial properties by the agar diffusion test (n = 15, per group) were analyzed. STATISTICAL ANALYSIS: Data were analyzed by Kruskal-Wallis test followed by Dunn, and one-way analysis of variance test followed by Tukey's test (p < 0.5). RESULTS: Morphological evaluation demonstrated intense inflammatory infiltrate in Groups M10 and KC10 in the time intervals of 7 (p = 0.001) and 15 (p = 0.006) days. Multinucleated giant cells were shown to be more present in Group M1, with statistical difference from Control and KC50 Groups in the time interval of 7 days (p = 0.033). The SBST showed no statistical significance among the groups (p > 0.05). Antibacterial property showed a statistically significant difference between Meron and Meron 50%-EEP Groups, and between Ketac and Ketac 50%-EPP Groups (p = 0.001). CONCLUSIONS: The intensity of histological changes resulting from the cements was shown to be inversely proportional to the concentration of propolis added; Ketac 50%-EPP was the concentration that had the most favorable biocompatibility results. Addition of EEP to GIC did not negatively change the SBST and ARI. Antibacterial property demonstrated a concentration-dependent effect.

Effect of Orthodontic Treatment on Tooth Autotransplantation: Systematic Review of Controlled Clinical Trials.

This systematic review was focused on evaluating tooth autotransplantation, considering its impacts on the teeth, bone, soft tissues, and aesthetics in orthodontic patients. A bibliographic search was conducted without limitations on year of publication or language in the databases of PubMed, Web of Science, Scopus, Medline Complete, Cochrane, Clinical Trials, and Trials Central. For triage of articles, indications, surgical planning, orthodontic movement, risk factors for treatment, and long-term follow-ups were considered. For outcomes, the results with reference to teeth, alveolar bone, periodontal tissues, and esthetic satisfaction were considered. Risk of bias was evaluated using the methodological index for nonrandomized studies-MINORS. The results showed 10 controlled clinical trials, and no randomized clinical trials were found. The selected studies included 715 patients and 934 autotransplanted teeth among which there were premolars, molars, and anterior teeth evaluated in the long term, indicating that orthodontics associated with autotransplantation indicated a result that was generally clinically acceptable. The quality of the set of evidence was considered medium due to the presence of different methodological problems, risk of bias, and significant heterogeneity in the evaluated studies. There was a sufficient body of evidence that justified autotransplantation in patients who needed orthodontic movement. In teeth, there was an increase in root resorption influenced by orthodontics, but without impacting on the general clinical result in the long term. Bone and periodontal tissue do not appear to be affected by orthodontics. The patient's aesthetic satisfaction was not considered in the studies.

New material perspective for endocrown restorations: effects on mechanical performance and fracture behavior.

The aim of this study was to investigate the mechanical performance and the fracture behavior of endocrown restorations prepared using distinct restorative materials. A total of 42 sound molars with similar crown size and shape were cut at 2 mm above the cementoenamel junction and endodontically treated. They were categorized according to the restorative material used to fabricate endocrown restorations (n=7), namely, conventional composite (Filtek™ Z350 XT), bulk fill composite (Filtek™ Bulk Fill), conventional composite modeled using resin adhesives (SBMP: Scotchbond™ Multipurpose Adhesive; or SBU: Scotchbond™ Universal Adhesive), and IPS e.max lithium disilicate (Ivoclar Vivadent; positive control). Unprepared sound teeth were used as negative control. All endocrowns were bonded using a self-adhesive cement (Rely-X™ U200). The teeth were submitted to fatigue (Byocycle) and fracture (EMIC DL500) testing. Load-to-fracture (in N) and work-of-fracture (Wf, in J/m2) values were analyzed by ANOVA (p < 0.05). The endocrowns did not fracture or de-bond upon fatigue, showing similar load-to-fracture and work-of-fracture values, regardless of the restorative material (p > 0.05). The endocrowns fabricated by combining Z350 and SBMP had the least harsh fractures, in contrast to endocrowns prepared using Z350 only, which exhibited an equilibrium between repairable and irrepairable fractures. The e.max endocrowns exhibited more aggressive failures (root fracture) than other groups, resulting in higher rates of irrepairable fractures. In conclusion, dental practitioners may satisfactorily restore severely damaged nonvital teeth using the endocrown technique. Composite endocrowns prepared using resin adhesive as modeler liquid or using bulk fill material may result in less aggressive failures, thus providing a new material perspective for endocrown restorations.