Antimicrobial potential of new diclofenac hydrogels for disinfection in regenerative endodontics: An in vitro and ex vivo study.

AIM: There is a need to explore new alternatives for root canal disinfection in regenerative endodontics, since the current strategies are far from ideal. Currently, the potential use of diclofenac (DC) is being investigated for controlling root canal infections. The objective was to evaluate the antimicrobial efficacy of novel DC-based hydrogels (DCHs) against polymicrobial biofilms grown in radicular dentine and root canals and to compare results with triantibiotic (TAH) and diantibiotic (DAH) hydrogels, and calcium hydroxide (Ca[OH]2 ). METHODOLOGY: The in vitro antimicrobial activity of intracanal medicaments was evaluated against 3-week-old polymicrobial root canal biofilms grown on human radicular dentine. Dentine samples were obtained and randomly divided into the study groups (n = 4/group): (1) 1 mg/ml TAH; (2) 1 mg/ml DAH; (3) 5% diclofenac (DCH); (4) 2.5% DCH; (5) 1.25% DCH; (6) 1 mg/ml DAH + 5% DCH; (7) Ca(OH)2 paste; (8) positive control. The microbial viability, in terms of percentage of intact cell membranes, was assessed after 7 days by confocal scanning laser microscopy (CSLM). The ex vivo efficacy of intracanal medications was evaluated in root canals infected with a polymicrobial suspension. Intracanal microbiological samples at baseline (S1) and 7 days post-treatment (S2) were taken; microbial quantification and cell viability were assessed by quantitative polymerase chain reaction (qPCR) and flow cytometry (FC). The mean Log10 of bacterial DNA copies in root canal samples before (S1) and the Log10 reduction of DNA copies S1-S2 in qPCR were recorded. The absolute value of total cells stained, and the percentage reduction of intact membrane cells after treatment (S1-S2), were analysed by FC. Global comparison was done using the Kruskal-Wallis test, whilst the Mann-Whitney U test was used for pair-by-pair comparison. RESULTS: Confocal scanning laser microscopy analysis indicated that the greatest effectiveness was obtained with 5% DCH, showing significant differences with respect to the other groups (p < .001). In root canals, the highest Log10 DNA reduction S1-S2 was obtained with 5% DCH and TAH, with no differences between them. The results of FC showed that only 5% DCH proved significantly superior to the other treatments. CONCLUSIONS: Sodium DC hydrogels demonstrate antimicrobial efficacy against endodontic biofilms.

Effectiveness of conservative instrumentation in root canal disinfection.

OBJECTIVES: The impact of conservative instrumentation on the disinfection of root canals with different curvatures has not yet been determined. This ex vivo study aimed to evaluate and compare the effect of conservative instrumentation with TruNatomy (TN) and Rotate and a conventional rotary system, ProTaper Gold (PTG), on root canal disinfection during chemomechanical preparation of straight and curved canals. MATERIALS AND METHODS: Ninety mandibular molars with straight (n = 45) and curved (n = 45) mesiobuccal root canals were contaminated with polymicrobial clinical samples. Teeth were divided into three subgroups (n = 14) according to the file systems and the curvature. Canals were instrumented with TN, Rotate, and PTG, respectively. Sodium hypochlorite and EDTA were used as irrigants. Intracanal samples were taken before (S1) and after (S2) instrumentation. Six uninfected teeth were used as negative controls. The bacterial reduction between S1 and S2 was measured by ATP assay, flow cytometry, and culture methods. Kruskal-Wallis and ANOVA tests were followed by the Duncan post hoc test (p < 0.05). RESULTS: Bacterial reduction percentages were similar for the three file systems in straight canals (p > 0.05). However, PTG showed a lower reduction percentage of intact membrane cells in flow cytometry than TN and Rotate (p = 0.036). For the curved canals, no significant differences were obtained (p > 0.05). CONCLUSION: Conservative instrumentation of straight and curved canals using TN and Rotate files resulted in similar bacterial reduction compared to PTG. CLINICAL RELEVANCE: The disinfection efficacy of conservative instrumentation is similar to conventional instrumentation in straight and curved root canals.

Evaluation of final irrigation regimens with maleic acid for smear layer removal and wettability of root canal sealer.

OBJECTIVE: To evaluate the smear layer removal and wettability of AH Plus sealer on root canal dentin treated with MA (maleic acid), MA + CTR (cetrimide) and MA + CTR + CHX (chlorhexidine) as final irrigating regimens. MATERIAL AND METHODS: For smear layer removal, 40 teeth were instrumented to size F4 and divided into four groups: (1) 7% MA, (2) 7% MA + 0.2% CTR, (3) 7% MA + 0.2% CTR + 2% CHX, (4) distilled water (control). After irrigation, teeth were subjected to SEM analysis. For contact angle analysis, 20 teeth were split longitudinally and divided into four groups similar to smear layer analysis. AH plus sealer was placed on each specimen and contact angle was analysed. RESULTS: In both smear layer (p = .393) and contact angle analysis (p = .961), there was no significant difference between the groups MA and MA + CTR. However, MA + CTR + CHX removed smear layer less effectively (p = .023) and increased the contact angle of the sealer (p = .005). In smear layer analysis, specimens in negative control group were heavily smeared. In case of contact angle analysis, samples in the control group had least contact angle. CONCLUSION: MA alone or in combination with CTR removed smear layer effectively and increased the wettability of AH plus sealer to root canal dentin.

Cluster Randomized Controlled Trial of Intervention to Increase Participant Retention and Completed Home Visits in the Nurse-Family Partnership.

We conducted a cluster-based randomized controlled trial of an intervention designed to improve participant retention in community replication sites of the Nurse-Family Partnership (NFP). We registered 26 sites and randomized them into three groups: retention intervention (RI, N = 9), delayed RI (DRI, N = 6), or control (C, NFP as usual, N = 11). The RI consisted of training nurses to give more explicit control over the frequency of visits and content of the program to the parent participants. Two of the sites assigned to the RI, two assigned to the DRI, and two out of four nurses in one other site assigned to the DRI chose not to participate in the intervention. Primary analyses (intention to treat) contrasted changes in participant retention and completed visits (the primary outcomes) in the two intervention groups (RI and DRI) compared to control sites, focusing on differences in performance among baseline cohorts compared to cohorts enrolled during the first year during which the retention intervention was implemented. Compared to baseline, retention declined in the control sites over time but stayed the same in the RI and DRI sites (p value for interaction = 0.099). Compared to baseline, the number of completed home visits declined over time in the control sites but did not in the RI and DRI sites, producing a significant treatment difference in change in mean completed home visits over time (2.71 visits, SE = 1.164, p = 0.020). The intervention offset a decline over time in retention and completed home visits found in the control group during the time covered by this trial. Quantitative and qualitative evaluation of the intervention indicated that improvements are needed to promote its uptake.

Antimicrobial activity of alexidine, chlorhexidine and cetrimide against Streptococcus mutans biofilm.

BACKGROUND: The use of antimicrobial solutions has been recommended to disinfect demineralized dentin prior to placing the filling material. The aim of this study was to evaluate the ability of several antimicrobials in controlling Streptococcus mutans (SM) biofilm formed in dentin. METHODS: Antimicrobial activity of 0.2% and 2% chlorhexidine (CHX), 0.2% cetrimide (CTR) and 0.2%, 0.5%, 1% and 2% alexidine (ALX) was assayed on 1-week SM biofilm formed on standardized coronal dentin blocks. Results of SM biofilm antimicrobial activity by different protocols were expressed as the kill percentage of biofilm and the term "eradication" was used to denote the kill of 100% of the bacterial population. To compare the efficacies of the different protocols the Student t test was used, previously subjecting data to the Anscombe transformation. RESULTS: All ALX concentrations tested and 0.2% CTR achieved a kill percentage higher than 99%, followed by 2% CHX with percentages above 96% (no statistically significant difference among them). Whereas 2% ALX and 0.2% CTR respectively showed eradication in 10 and 9 of the twelve specimens, 0.2% CHX did not produce eradication in any case. CONCLUSIONS: The present study shows that, when used for one minute, 2% and 1% alexidine, and 0.2% cetrimide, achieve eradication of Streptococcus mutans biofilm in most specimens when applied to a dentin-volumetric model.

Bacterial leakage in root canals filled with AH Plus and dentine bonding agents.

OBJECTIVE: The aim of this study was to compare the efficacy of different dentine adhesives in delaying the coronal bacterial leakage of Enterococcus faecalis in filled root canals. Materials and methods. Ninety-five lower incisors of patients >65 years of age were instrumented using the ProTaper system and were irrigated with 1 mL of 2.5% sodium hypochlorite (NaOCl) alternated with 1 mL 17% EDTA between each file change. Final irrigation was performed with 5 mL of 17% EDTA and then flushed with 5 mL of distilled water. The teeth were randomly divided into five experimental groups (n = 15/group) and one of the following dentine adhesives was applied: (1) AdheSE; (2) Excite DSC; (3) Clearfil Protect Bond; (4) One Coat 7.0; or (5) Control group without adhesive. After filling the root canals, the samples were mounted on a double chamber device to evaluate the bacterial filtration of E. faecalis during a period of 240 days. The results underwent non-parametric Kaplan-Meier survival analysis and comparisons among groups were done using the Log-Rank test. RESULTS: At 240 days, E. faecalis was detected in samples of all groups in the lower chamber. The highest survival value was obtained by One Coat 7.0, giving statistically significant differences from the other groups, whereas Clearfil Protect Bond, AdheSE and Excite DSC showed similar behaviours, likewise similar to the Control group. CONCLUSIONS: One Coat 7.0 adhesive system provides the longest survival value to delay E. faecalis coronal leakage in filled root canals.

Novel Ti surface coated with PVA hydrogel and chitosan nanoparticles with antibacterial drug release: An experimental in vitro study.

OBJECTIVES: The aims of this study were to design a novel titanium surface coated with a PVA hydrogel matrix and chitosan-based nanoparticles and to investigate the antibiotic release and its ability to inhibit microbial activity. METHODS: Two drug delivery systems were developed and mixed. Chitosan-based nanoparticles (NP) and a polyvinyl alcohol film (PVA). The size, ζ-potential, stability, adhesive properties, and encapsulation profile of NP, as well as the release kinetics of drug delivery systems and their antimicrobial ability of PVA and PVANP films, were studied on Ti surfaces. The systems were loaded with doxycycline, vancomycin, and doxepin hydrochloride. RESULTS: Nanoparticles presented a ζ-potential greater than 30 mV for 45 days and the efficiency drug encapsulation was 26.88% ± 1.51% for doxycycline, 16.09% ± 10.24% for vancomycin and 17.57% ± 11.08% for doxepin. In addition, PVA films were loaded with 125 µg/mL of doxycycline, 125 µg/mL of vancomycin, and 100 µg/mL of doxepin. PVANP-doxycycline achieved the antibacterial effect at 4 h while PVA-doxycycline maintained its effect at 24 h.

Quasi-experimental pilot study of intervention to increase participant retention and completed home visits in the nurse-family partnership.

We evaluated an intervention to increase participant retention and engagement in community practice settings of the Nurse-Family Partnership (NFP), an evidence-based program of nurse home visiting for low-income, first-time parents. Using a quasi-experimental design (6 intervention and 11 control sites that delivered the NFP), we compared intervention and control sites on retention and number of completed home visits during a 10-month period after the intervention was initiated. Nurses at the five intervention sites were guided in tailoring the frequency, duration, and content of the visits to participants' needs. NFP nurses at the control sites delivered the program as usual. At the intervention sites, participant retention and completed home visits increased from the pre-intervention to intervention periods, while at the control sites, these outcomes decreased from the pre-intervention to intervention periods, leading to a significant intervention-control difference in change in participant retention (hazard ratio, 0.42; p = 0.015) and a 1.4 visit difference in change in completed home visits (p < 0.001, ES = 0.36). We conclude that training nurse home visitors to promote adaptation of program dosage and content to meet families' needs shows promise as a way to improve participant retention and completed home visits.

Levels of scientific evidence of the quality of life in patients treated for oral cancer.

Treatments used in cancer of the oral cavity have great impact on the physical, psychological and functional state of patients. There has been increasingly interest in evaluating the health-related quality of life using questionnaires among patients treated with oral cancer. Up to our knowledge no review on this theme has incorporated the level of evidence of the single identified studies. The objective of the present study is to determinate results and conclusions about the health-related quality of life of these patients, in view of scientific evidence. In general, the diversity of designs, level of evidence and questionnaires used for their assessment does not affect results, which indicate a decline in the health related quality of life after treatment. This decline is greater when the tumor is large in size, and when radiotherapy is used, though the situation is seen to improve over the span of a year. Questionnaires on health-related quality of life provide concrete information regarding the impact of cancer treatment on patients.

Decalcifying effects of antimicrobial irrigating solutions on root canal dentin.

OBJECTIVE: The aim of this study was to determine the decalcifying efficacy of 7% maleic acid (MA), 2% chlorhexidine (CHX), and combinations of 7% MA + 0.2% cetrimide (CTR) and 2% CHX + 0.2% CTR, in four time periods. STUDY DESIGN: Four specimens per tooth were obtained from a 2-mm thick slice of the cervical third of the root of ten human incisors. At 1, 2, 3 and 5 minutes of immersion, the concentrations of Ca2+ were measured by atomic absorption spectrophotometry. The results were analyzed using the Mann-Whitney U-test. RESULTS: Statistically significant differences were seen for the extracted calcium in all time periods. The amount of calcium extracted by 7% MA was the highest at all four immersion times, followed by 7% MA + 0.2% CTR. Two percent CHX and its combination with 0.2% CTR extracted virtually no calcium. CONCLUSIONS: The decalcifying capacity of 7% MA and 2% CHX diminished when combined with 0.2% CTR.

Ex vivo study of bacterial coronal leakage in indirect pulp treatment.

OBJECTIVE: The aim of this study was to evaluate, ex vivo, bacterial coronal leakage with different antimicrobial agents applied to the dentine for indirect pulp treatment (IPT). STUDY DESIGN: Sixty extracted teeth were prepared and randomly distributed into 5 groups (n=10): Group 1: no antimicrobial dentine treatment; group 2: 1% chlorhexidine (CHX)+1% thymol varnish (Cervitec); group 3: 2 % CHX solution; group 4: 40% CHX varnish (EC40) and group 5: Clearfil Protect Bond (CPB). Ten teeth served as controls. The teeth were restored using a resin-modified glass ionomer cement (GIC) and then mounted in a two-chamber device. The coronal access was exposed to Streptococcus mutans for 45 days. The appearance of turbidity in the BHI broth of the lower chamber was considered as specimen leakage. RESULTS: Survival analysis, determined by non parametric Kaplan-Meier and log-rank tests, showed that the best results were for groups EC40+GIC and GIC alone; yet there were not statistically significant differences between them. All specimens of CPB+GIC and 2% CHX+GIC, leaked at 45 days. CONCLUSIONS: In IPT the use of GIC without pretreatment of the dentine and pretreatment with 40% CHX varnish resulted in a significant delay of bacterial coronal leakage.

Efficacy of mixed diclofenac solutions against root canal biofilms.

The objective of this research was to evaluate the efficacy of diclofenac sodium solutions, with or without cetrimide (CTR) added, against polymicrobial root canal biofilms grown in dentin specimens. The study groups were: (1) 5% diclofenac sodium (DCS); (2) 2.5% DCS; (3) 2.5% DCS + 0. 2% CTR; (4) 2.5% DCS + 0.4% CTR and (5) 0.9% saline solution (SS) as the control. After 5 min of solution contact with the biofilms, the antimicrobial activity was evaluated by means of the adenosine triphosphate (ATP) assay as well as confocal laser scanning microscopy (CLSM). Microbial quantification was indicated as the percentage reduction of relative light units (RLUs) for the ATP assay, the Log10 total biovolume and the viability percentage (green cells) for CLSM. Solutions of 2.5% DCS + 0.4% CTR and 5% DCS showed the highest antimicrobial efficacy. Cetrimide increased the antibiofilm activity of diclofenac sodium against endodontic biofilms.

Biological and chemical properties of 2-in-1 calcium-chelating and antibacterial root canal irrigants.

OBJECTIVES: To evaluate the capacity of canal wall smear layer removal, precipitation caused by irrigant interaction, antibacterial activity and cytotoxicity of three 2-in-1 root canal irrigating solutions. METHODS: Forty single-rooted teeth were mechanically instrumented and irrigated with QMix, SmearOFF, Irritrol or 0.9% saline. Each tooth was evaluated for smear layer removal using scanning electron microscopy. Precipitation after interaction of the irrigating solutions with sodium hypochlorite (NaOCl) was evaluated with 1H nuclear magnetic resonance and mass spectroscopy. Confocal laser scanning microscopy was used to evaluate the antimicrobial activity of the irrigants against Enterococcus faecalis biofilms. Neutral red and clonogenic assays were performed on Chinese hamster V79 cells to evaluate the short-term and long-term cytotoxicity of the irrigants. RESULTS: There was no significant difference between QMix and SmearOFF in eliminating smear layers from the coronal-third and middle-third of the canal spaces. In the apical-third, SmearOFF removed smear layers effectively. Irritrol incompletely removed smear layers from all the canal-thirds. When mixed with NaOCl, precipitation was evident only with Irritrol. QMix demonstrated a higher E. faecalis cell death percentage and a smaller biovolume. SmearOFF exhibited a larger decrease in biovolume compared with Irritrol, although Irritrol had a higher death percentage. Irritrol was more cytotoxic than the other irrigants on a short-term interval. In terms of long-term cytotoxicity, both Irritrol and QMix were cytotoxic. CONCLUSION: QMix and SmearOFF performed better in smear layer removal and antimicrobial activity. QMix and Irritrol were cytotoxic when compared to SmearOFF. Irritrol was associated with precipitation after interacting with NaOCl. CLINICAL SIGNIFICANCE: Evaluation of the smear layer removal capability, antibacterial activity and cytotoxicity of 2-in-1 root canal irrigants is necessary to ensure that they are safe to use during root canal treatment.

Three-dimensional evaluation of root canal morphology in lower second premolars of early and middle Pleistocene human populations from Atapuerca (Burgos, Spain).

The aim of this study is to describe the morphology of the roots and root canals of permanent lower second premolars (LP4s) with fully developed roots of five hominin groups: Homo sp. (ATE9-1 specimen) from Atapuerca-Sima del Elefante locality, H. antecessor (ATD6-4 and ATD6-125) from Atapuerca-Gran Dolina TD6 locality, H. heidelbergensis from Atapuerca-Sima de los Huesos locality, H. neanderthalensis from Krapina, Regourdou, and Abri Bourgeois-Delaunay localities, and two contemporary H. sapiens groups. The teeth were scanned by means of microtomography. The roots were divided into three virtual segments by three planes: cemento-enamel junction (CEJ), mid-root (MR), and mid-apex (MA). Volumetric and planar direct measurements of the whole teeth and each segment were taken. Descriptive statistical analyses and nonparametric Mann-Whiney test were performed to test for significant differences (P < 0.025) between groups. ATE9-1 and Gran Dolina-TD6 fossils present intricate radicular complexes that might be transitional between the morphologies of Australopithecus robustus and African early Homo and the derived conditions typically found in later Homo. In H. neanderthalensis and H. heidelbergensis, the root canals are wide, with small apical convergence. This trait is particularly pronounced in the Sima de los Huesos sample which may reflect a particularity of this population. Our study demonstrates the potential of hominin roots and root canals as untapped sources of taxonomic information when the tooth crown is fragmented. Future studies, including more fossil specimens and species will shed light in the polarity of the morphologies observed.

Horizontal transmission of Streptococcus mutans in schoolchildren.

OBJECTIVE: The aim of this study was to analyze possible horizontal transmission patterns of S. mutans among 6-7-yr-old schoolchildren from the same class, identifying genotypes and their diversity and relationship with caries disease status. STUDY DESIGN: Caries indexes and saliva mutans streptococci and lactobacilli counts were recorded in 42 schoolchildren. Mutans streptococci colonies were identified by means of biochemical tests and all S. mutans strains were genotyped by arbitrarily primed polymerase chain reaction. A child was considered free of S. mutans when it could not be isolated in 3 samples at 1-week intervals. RESULTS: S. mutans was isolated in 30 schoolchildren: 20 having one genotype and 10 two genotypes. Higher mutans streptococci and caries index values were found in those with two genotypes. Five genotypes were isolated in more than 1 schoolchild and one of these was isolated in 3 schoolchildren. Our results suggest that horizontal transmission may take place. CONCLUSION: Schoolchildren aged 6-7 yrs may be the source of mutual transmission of S. mutans.

Eradication of enterococci biofilms by lactic acid alone and combined with chlorhexidine and cetrimide.

OBJECTIVE: The antimicrobial activity of lactic acid (LA) alone or in combination with chlorhexidine (CHX) and cetrimide (CTR) against three Enterococcus faecalis strains, E. faecalis ATCC 29212, E. faecalis EF-D1 and E. faecalis U-1765, one Enterococcus durans strain and one dual-species biofilm was investigated. STUDY DESIGN: The irrigating solutions tested were 20%, 15%, 10%, 5% and 2.5% LA, alone and in combination with 2% CHX and with 0.2% CTR. The biofilms were grown in the MBECTM high-throughput device for 24 hours and exposed to the solutions for 30 seconds and 1 minute. "Eradication" was defined as 100% bacterial kill. RESULTS: Twenty percent LA eradicated all enterococci biofilms after 30 seconds contact time. The association of LA+0.2% CTR achieved better results than LA alone, in contrast with the results obtained using LA+2% CHX. E. durans was eradicated by all the tested solutions at 1 minute. The dual-species biofilm, E. faecalis ATCC 29212+E. durans, gave intermediate values of the pure cultures. CONCLUSIONS: LA is capable of eradicating enterococci biofilm at a concentration of 20%. The combination of lower concentrations with 0.2% CTR achieved eradication after 1 minute.

Antimicrobial activity and enterococcus faecalis biofilm formation on chlorhexidine varnishes.

OBJECTIVE: To evaluate, in vitro, the antimicrobial activity and biofilm formation of three chlorhexidine varnishes in four E. faecalis strains: E. faecalis ATCC 29212, E. faecalis EF-D1 (from failed endodontic treatment), E. faecalis 072 (cheese) and E. faecalis U-1765 (nosocomial infection), and one E. durans strain (failed endodontic treatment). STUDY DESIGN: The direct contact test was used to study the antimicrobial activity. Bacterial suspensions were exposed for one hour to EC40, Cervitec (CE) and Cervitec Plus (CEP) varnishes. "Eradication " was defined as 100% bacterial kill. The formation of enterococci biofilms was tested on the surface of the varnishes after 24 hours of incubation and expressed as percentage of biofilm reduction. RESULTS: EC40 eradicated all strains except E. faecalis ATCC 29212, where 98.78% kill was achieved. CE and CEP showed antimicrobial activity against all the strains, but most clearly against E. durans and E. faecalis 072. EC40 completely inhibited the formation of biofilm of E. faecalis ATCC 29212, E. faecalis 072 and E. durans. CE and CEP led to over 92% of biofilm reduction, except in the case of E. faecalis U-1765 on CEP (76.42%). CONCLUSION: The three varnishes studied were seen to be effective in killing the tested strains of enterococci and in inhibiting the formation of biofilm, the best results being observed with EC40.

In vitro Enterococcus faecalis biofilm formation on five adhesive systems.

OBJECTIVE: To determine the E. faecalis biofilm formation on the surface of five adhesive systems (AS) and its relationship with roughness. STUDY DESIGN: The formation of E. faecalis biofilms was tested on the surface of four dual-cure AS: AdheSE DC, Clearfil DC Bond, Futurabond DC and Excite DSC and one light-cure antimicrobial AS, Clearfil Protect Bond, after 24 hours of incubation, using the MBEC high-throughput device. RESULTS: E. faecalis biofilms grew on all the adhesives. The least growth of biofilm was on Excite DSC, Clearfil Protect Bond, and the control. Futurabond DC resulted in the greatest roughness and biofilm amount. There was a close relationship between the quantity of biofilm and roughness, except for Clearfil Protect Bond, which showed little biofilm but high roughness. CONCLUSION: None of the tested AS prevented E. faecalis biofilm formation, although the least quantity was found on the surface of Clearfil Protect Bond.

Current status on antimicrobial activity of a tricalcium silicate cement.

Biodentine (BD) is a bioactive material with many indications in endodontic therapy. The purpose of this study was to compile and review the outcomes of in vitro and in vivo studies of BD in terms of antimicrobial effectiveness. An electronic search was carried out in PubMed, from January 2009-April 2021 using the keywords: (Biodentine or dentine substitute or "Ca3SiO5" or tricalcium silicate cement or bioceramic cement) and (antimicrobial activity or antimicrobial effect or antimicrobial effectiveness or antibacterial activity or antibacterial effect or antibacterial effectiveness or antibiofilm activity or antibiofilm effectiveness). Two independent reviewers evaluated the studies for eligibility. All studies that did not include BD or its antimicrobial properties, as well as abstracts not written in English, were excluded. This review identified the need to develop standardized methods to evaluate antimicrobial activity in vitro. Most of the studies were against planktonic bacteria and gave conflicting results. Studies ex vivo and in vivo against biofilm are required to elucidate the antimicrobial activity of BD.

Root Canal Disinfection Articles with the Highest Relative Citation Ratios. A Bibliometric Analysis from 1990 to 2019.

The relative citation rate (RCR) is a normalized article-level metric useful to assess the impact of research articles. The objective of this bibliometric study is to identify and analyze, in root canal disinfection, the 100 articles having the highest RCRs in the period 1990-2019, then compare them with the top 100 articles most cited. A cross-sectional study was performed, and the search strategy ((Disinfection AND root canal) AND (("1990/01/01"[Date-Publication]: "2019/12/31"[Date-Publication]))) relied on PubMed (n = 4294 documents), and article data were downloaded from the iCite database. The 100 articles with the highest RCRs and the top 100 cited were selected and evaluated in bibliometric terms. Among the 100 articles with the highest RCRs, there were no differences in the three decades for RCRs values, but there were in citations, being 2000-2009 the most cited. The USA was the predominant country (n = 30), followed by Brazil (n = 14). The most frequent study designs were reviews (n = 27) and in vitro (n = 25) and ex vivo (n = 24) studies. All subfields were well represented, although they varied over time. In 2010-2019, regenerative procedures and irrigation/disinfection techniques were predominant. Considering the RCR's top 100 articles, 76 were common with the 100 most cited articles. Using the RCR metric allowed us to identify influential articles in root canal disinfection, a research field with topics of significance that fluctuate over time. Compared to citations, RCR reduces the time from publication to detection of its importance for the readership and could be a valid alternative to citation counts.