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Being an important Islamic concept, tawakkul is a fundamental and core value in the Islamic belief system. The present research intended to investigate the mediating role of tawakkul between religious orientation and depression. A purposive sample of (N = 350) Muslim adults with the age of 25 years and above (M = 31.92, SD = 8.72) was recruited in the study. A cross-sectional survey research design was used. Tawakkul Scale (Gondal et al., 2021), Urdu version of depression subscale of DASS-21 (Aslam, 2018), and Urdu version of Religious Orientation Scale (Khan, et al., 2016) were used in the present study. Results indicated that tawakkul had a negative relationship with depression and extrinsic social religious orientation. On the other hand, it had a positive relationship with intrinsic religious orientation and extrinsic personal religious orientation. The findings of the path model indicated that tawakkul mediated the relationships of intrinsic and extrinsic personal religious orientations with depression. Limitations, implications of the findings of the present study, and suggestions for future investigations have been reflected upon.

The ‘Focal Infection Era in Dentistry’ in the late 19th and early 20th century resulted in widespread implementation of tooth extraction and limited the progress of endodontics. The theory proposed that bacteria and toxins entrapped in dentinal tubules could disseminate systemically to remote body parts, resulting in many types of degenerative systemic diseases. This theory was eventually refuted due to anecdotal evidence. However, lately there has been increased interest in investigating whether endodontic disease could have an impact on general health. There are reviews that have previously been carried out on this subject, but as new data have emerged since then, this review aims to appraise the available literature investigating the dynamic associations between apical periodontitis, endodontic treatment, and systemic health. The available evidence regarding focal infection theory, bacteraemia and inflammatory markers was appraised. The review also collated the available research arguing the associations of apical periodontitis with cardiovascular diseases, diabetes mellitus, adverse pregnancy outcome and autoimmune disorders, along with the effect of statins and immunomodulators on apical periodontitis prevalence and endodontic treatment prognosis. There is emerging evidence that bacteraemia and low-grade systemic inflammation associated with apical periodontitis may negatively impact systemic health, e.g., development of cardiovascular diseases, adverse pregnancy outcomes, and diabetic metabolic dyscontrol. However, there is limited information supporting the effect of diabetes mellitus or autoimmune disorders on the prevalence and prognosis post endodontic treatment. Furthermore, convincing evidence supports that successful root canal treatment has a beneficial impact on systemic health by reducing the inflammatory burden, thereby dismissing the misconceptions of focal infection theory. Although compelling evidence regarding the association between apical periodontitis and systemic health is present, further high-quality research is required to support and establish the benefits of endodontic treatment on systemic health.

Introduction This survey reports the incidence of traumatic dental injuries in an adult population attending an adult dental trauma clinic in a London teaching hospital.Materials and methods Retrospective data were collected from patients attending an adult dental trauma clinic between 2012 and 2018.Results In total, 1,769 patients attended, with more men seen (1,030; 58.2%) compared to women (739; 41.8%) and this was statistically significant (p Discussion This retrospective survey attempts to report on the incidence of traumatic dental injuries in a London-based cohort of patients attending a specialised dental trauma clinic. In line with other reports, there were more men than women affected, which is probably attributed to behavioural activities.Conclusion(s) Accidental falls are the most common cause of a traumatic dental injury, lateral luxation was the most common type of displacement injury and enamel-dentine fractures were the most common type of fracture injury.

Bacteraemia associated with invasive dental treatments can propagate infective endocarditis in high-risk cardiac patients. Over the past decade, antibiotic prophylaxis before dental treatment has been questioned. This review aims to compare the variations between the UK, European and American antibiotic prophylaxis guidelines before dental treatments. Antibiotic prophylaxis guidelines by the National Institute for Health and Care Excellence (NICE)—Clinical Guideline 64, Scottish Dental Clinical Effectiveness Programme (SDCEP), American Heart Association (AHA), European Society of Cardiology (ESC), European Society of Endodontology (ESE) and Belgian Health Care Knowledge Centre (KCE) position statements were compared regarding the indications, high-risk patients and prophylaxis regimens before dental treatments. In the United Kingdom, the NICE—Clinical Guideline 64 and SDCEP—Implementation Advice do not advise the prescription of prophylactic antibiotics for the majority of high-risk cardiac patients undergoing routine dental treatments. On the contrary, the AHA, ESC and KEC recommend the prescription of antibiotics prior to invasive dental procedures in high-risk cardiac individuals. The ESE also indicates prophylaxis before endodontic procedures for patients with other conditions, including impaired immunologic function, prosthetic joint replacement, high-dose jaw irradiation and intravenous bisphosphonates. Among these guidelines, there are variations in antibiotic prophylaxis regimens. There are variations regarding the indications and antibiotic prophylaxis regimens before invasive dental treatments among these available guidelines.

IntroductionThe aim of this retrospective cohort study was to investigate the prevalence of apical periodontitis (AP) in patients affected by autoimmune diseases (ADs) taking biologic medications (BMs).MethodsNinety-nine patients (2440 teeth) with ADs referred to the university clinic for dental evaluation were investigated. The controls included 99 patients (2655 teeth) with no systemic diseases and taking no medications. The patients underwent a complete oral, dental, and radiographic examination for the presence of AP. The periapical index and the status of endodontic and restorative treatments were obtained. Statistics were based on descriptive analysis and continuous variables for the total sample and by subgroups. Adjusted odds ratios and 95% confidence intervals were calculated.ResultsThe prevalence of AP was 65.7% in the autoimmune diseases group (AI) and 46.5% in the controls (P ≤ .05). The association between smoking and AP was significant (P ≤ .05). Among the AI subgroups, rheumatoid arthritis patients at the tooth level had a lower probability of developing AP than patients with inflammatory bowel disease (P ≤ .05). Furthermore, each additional year of age implied a +1% risk of AP; women had a lower periapical index than men in both groups (P ≤ .05), and tocilizumab was associated with a reduced risk of AP compared with infliximab (P ≤ .05).ConclusionsPatients with ADs taking BMs had a higher prevalence of AP. These results indicate that the status of the patients' immune system may have an effect on the development and prevalence of AP.

Introduction The aim of this study was to evaluate the bacterial contamination in endodontic consumables (gutta-percha points, rubber dams, paper mixing pads, caulking agents, and endodontic instrument sponges [EISs]) before and after clinical use and storage. Methods Materials were randomly sampled in triplicates at 3 time points (t 0 , at package opening; t 1 , at 7 days; and t 2 , at 14 days) during their clinical usage. The gutta-percha points and caulking agent (25 mg) were added to 1 mL phosphate-buffered saline (PBS). The rubber dam, paper mixing pad, and EIS were added to 25 mL PBS. After vortexing, centrifuging, and removing the supernatant, the pellet was resuspended in 1 mL PBS, plated on fastidious anaerobic agar, and incubated aerobically and anaerobically. The grown colonies were identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). The total bacterial load was calculated in the remaining volume (800 μL) from each sample by quantitative polymerase chain reaction after DNA extraction. Results All tested materials showed a varied number of contaminated samples at the 3 time points (except EIS at t 0 ) using MALDI-TOF MS. The most isolated genera were Propionibacterium (42%) and Staphylococcus (32%). By using non–culture-based approaches, all tested materials at the 3 time points (except gutta-percha at t 0 and the caulking agent at t 0, t 1, and t 2 ) carried bacterial DNA. Conclusions The majority of the tested materials harbored bacteria in their samples before and after clinical storage. Nosocomial infection derived from commonly used consumables could have an impact on the outcome of endodontic treatment.

Bacteria present in the root canal (RC) space following an RC treatment (RCT) can lead to persistent infections, resulting in treatment failure and the need for reintervention or extraction. Currently, there are no standardized methods in use to clinically detect bacterial presence within RC spaces. The use of paper point sampling and fluorescence staining was shown to be a rapid method, able to detect residual bacteria following treatment. The study demonstrated that Calcein acetoxymethyl (AM) proved to be a suitable dye for detecting vital bacteria within mature endodontic biofilms, with an improved sensitivity over colony-forming unit counting in a stressed biofilm model. Furthermore, in a clinical trial with primary RCTs, 53 infected teeth were sampled in vivo, and increased detection of vital cells was found when compared with colony-forming unit counting, highlighting the sensitivity of the technique in detecting low cell numbers. By combining fluorescent staining and microspectroscopy with software-based spectral analysis, successful detection of vital cells from RCs was possible after 5 min of Calcein AM incubation. Application of this technology during RCT has the potential to reduce persistent infections through vital cell detection and additional treatment. Furthermore, this technique could be applied to antimicrobial research and disinfection control in clinical settings ( ClinicalTrials.gov NCT03055975).

Este artículo se encuentra disponible en la siguiente URL: https://www.thieme-connect.com/products/ejournals/pdf/10.1055/s-0040-1701541.pdf Objective The purpose of this research was to investigate the effect per se of two shaping and cleaning techniques on the reduction of an in vitro multispecies biofilm. Materials and Methods A total of 39 freshly extracted monoradicular teeth for periodontal reason were decoronated. Roots were sectioned longitudinally. After autoclaving, a specific stressed biofilm was grown on the root halves that were subsequently reassembled in a silicone index. Two treatments (n = 9 each)—RaCe (Schottlander; Letchworth Garden City, United Kingdom) and ProTaper Gold (PTG; Dentsply Maillefer, Baillagues, Switzerland)—were tested; three noninstrumented samples served as a control group and three were rinsed with saline. Posttreatment samples were taken at three different levels of the root. Colony-forming units were counted after incubations. Additionally, three treatments (n = 5 each)—RaCe, PTG, and saline only—were evaluated under a confocal laser scanning microscope (CLSM). Statistical Analysis Statistical analysis was conducted using Tukey’s test and analysis of variance to evaluate the post-instrumentation bioburden. Results Both instrumentations were able to reduce the biofilm; however, differences were not present between them (p > 0.05). CLSM showed biofilm killing and disruption through mechanical shaping alone. Conclusions Intraradicular biofilm is reduced with mechanical shaping. There was no difference between RaCe and PTG systems in biofilm reduction despite differences in design, file sequence, and rotational speed.

Objective The deleterious caustic effects of sodium hypochlorite (NaOCl) as a root canal irrigant makes it imperative that alternative methods are developed for root canal disinfection. The purpose of this study was to examine the antimicrobial efficacy of silver nanoparticles (AgNPs) synthesized on an aqueous graphene oxide (GO) matrix (Ag-GO), with different irrigant delivery methods to enhance the disinfection regimen, using a novel ex vivo infected tooth model. Methods AgNPs were prepared by reducing AgNO3 with 0.01 M NaBH4 in presence of GO. Elemental analysis was performed with scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDS) and scanning transmission electron microscopy (STEM) was used for size and morphology analysis of GO and Ag-GO. Nutrient stressed, multi-species biofilms were grown in prepared root canals of single-rooted teeth. The irrigants used were sterile saline, 1% and 2.5% NaOCl, 2% chlorhexidine gluconate (CHX), 17% EDTA and an aqueous suspension of 0.25% Ag-GO. The antimicrobial efficacy of the irrigants were performed with paper point sampling and measurement of microbial counts. The biofilm disruption in dentine tubule surfaces was analysed with confocal laser scanning microscopy (CLSM). The acquisition of total biovolume (μm3/μm2) and biofilm viability was performed using software BioImage_L. Two-way analysis of variance (ANOVA) with post hoc Tukey tests was used for data analysis with level of statistical significance set at P Results SEM/EDS analysis confirmed impregnation of Ag within the GO matrix. TEM images showed polygonal GO sheets and spherical AgNPs of diameter 20–50 nm, forming a network on the surface of GO sheets. The use of ultrasonic activation enhanced the efficacy of Ag-GO compared to 1% NaOCl, 2% CHX, 17% EDTA and sterile saline (P Significance The successful documentation of the microbial killing and biofilm disruption capacity of Ag-GO is a promising step forward to explore its unique properties in clinical applications and biomaterials in dentistry.

Introduction The opportunistic Propionibacterium acnes recovered frequently from failed endodontic treatments might be the result of nosocomial endodontic infections. The study was aimed to determine if gloves worn by dentists could be 1 of the sources of these nosocomial infections and to investigate the P. acnes phylotypes involved. Methods The cultivable microbiota of gloves (n = 8) at 4 time points (T1, immediately after wearing gloves; T2, after access cavity preparation; T3, after taking a working length/master cone radiograph; and T4, before sealing the cavity) were identified using 16S ribosomal RNA gene sequencing. recA gene sequencing of P. acnes isolates was done. The phylogenetic relationship was determined using MEGA 6 (http://www.megasoftware.net/fixedbugs.html; Megasoftware, Tempe, AZ). Data distributions were compared using the Fisher exact test; means were compared using the Mann-Whitney U test in SPSSPC (version 21; IBM, Armonk, NY). Results The quantitative viable counts at T4 (aerobically [2.93 ± 0.57], anaerobically [3.35 ± 0.43]) were greater (P

Objectives Eugenol has been used in dentistry due to its ability to inhibit the growth of a range of microorganisms, including facultative anaerobes commonly isolated from infected root canals. The aim of this study was to evaluate the antibacterial activity of the experimental composites containing eugenyl methacrylate monomer (EgMA), a polymeric derivative of eugenol, against a range of oral bacteria, commonly associated with failure of coronal and endodontic restorations. In vitro composite behavior and wettability were also studied in conjunction with their antibacterial activity. Methods EgMA monomer (5 and 10% by weight) was added into BisGMA/TEGDMA resin based formulations with filler mixtures of hydroxyapatite (HA) and zirconium oxide ZrO2. The antibacterial activity of the experimental composites against Enterococcus faecalis, Streptococcus mutans and Propionibacterium acnes were evaluated by direct contact test and compared with composite formulation without inclusion of EgMA. To clarify the antibacterial mode of action, agar diffusion test (ADT) was also performed. Water sorption, solubility, diffusion coefficient, contact angle and surface free energy as complementary clinically relevant properties were determined. Results Water sorption and wettability studies showed reduction of water uptake and surface free energy values with increasing content of EgMA monomer, resulting in significant increase in the hydrophobicity of the composites. No inhibition zones were detected in any of the composites tested against the three bacteria employed as expected, due to the absence of any leachable antibacterial agent. The covalently anchored EgMA monomer with the composite surface exhibited an effective bacteriostatic activity by reducing the number of CFUs of the three species of bacteria tested with no significant dependence on the concentration of EgMA at 5 and 10% by weight. The surface antibacterial activity R of the experimental composites were different against the three tested species with values in the range 2.7–6.1 following the order E. faecalis < S. mutans < P. acnes. Significance The incorporation of EgMA monomer within polymerizable formulations provides a novel approach to yield intrinsically antibacterial resin composites for different dental applications.

OBJECTIVES: The presence of opportunistic pathogens such as Propionibacterium acnes (P. acnes) may contribute to the endodontic pathology. The presence of P. acnes may be influenced by different endodontic conditions. The aims of the study were firstly, to identify P. acnes within the whole cultivable microbiota of primary endodontic infections, to investigate which P. acnes phylotypes predominate in such infections and secondly to determine if the presence of an "open" communication (e.g. a sinus) can be associated with the isolation of P. acnes from the root canal.MATERIAL AND METHODS: The predominant cultivable microbiota of 15 primary endodontic lesions (7 without communication with the oral environment and 8 with an open communication) were identified using partial 16S ribosomal RNA (rRNA) gene sequence analysis. The identification of the organism was determined by interrogating the Human Oral Microbiome Database. The P. acnes isolates were typed on the basis of the recA gene sequence comparison. A neighbor-joining tree was constructed using MEGA 4.1 with the inclusion of known recA sequences.RESULTS: There was no difference in the number of species identified from lesions without communication (5.86 ± 3.7) and those with communication (5.37 ± 3.6) (P > 0.05). PCR-based 16S rRNA gene sequencing revealed P. acnes as the most prevalent isolate recovered from lesions with communication. recA gene sequencing revealed two phylogenetic lineages present in lesion with communication, with mainly type I (further split into type IA and type IB) and type II.CONCLUSIONS: The presence of P. acnes as opportunistic pathogens has been confirmed and may sustain the traits observed in specific clinical presentations.CLINICAL RELEVANCE: Clinical management of open lesions may require further disinfection to eliminate opportunistic bacteria.

Purpose: This study compared the antimicrobial efficacy of calcium silicate sealers (BioRoot RCS and Total Fill BC) and conventional sealers (AH Plus and Tubli-seal) against planktonic bacteria and a nutrient-stressed multispecies biofilm. Methods: Antimicrobial properties of freshly mixed sealers were investigated using the direct contact test (DCT) and a nutrient-stressed multispecies biofilm comprised of five endodontic strains. Antimicrobial activity was determined using quantitative viable counts and confocal laser scanning microscopy (CLSM) analysis with live/dead staining. The pH of the sealers was analysed over a period of 28 days in Hanks Balanced Salt Solution (HBSS). Analysis of variance (ANOVA) with Tukey tests and the Kruskal&ndash, Wallis test were used for data analysis with a significance of 5%. Results: All endodontic sealers exhibited significant antimicrobial activity against planktonic bacteria (p &lt, 0.05). BioRoot RCS caused a significant reduction in viable counts of the biofilms compared to AH Plus and the control (p &lt, 0.05), while no significant difference could be observed compared to TotalFill BC and Tubli-seal (p &gt, 0.05). CLSM analysis showed that BioRoot RCS and TotalFill BC exhibited significant biofilm inhibition compared to Tubli-seal, AH Plus and the control (p &lt, 0.05). BioRoot RCS presented with the highest microbial killing, followed by TotalFill BC and Tubli-seal. Alkalizing activity was seen from the onset by BioRoot RCS, TotalFill BC and AH Plus. After 28 days, BioRoot RCS demonstrated the highest pH in HBSS (pH &gt, 12). Conclusions: Calcium silicate sealers exhibited effective antimicrobial properties. This was demonstrated by superior biofilm inhibition capacity and microbial killing, with strong alkalizing activity compared to epoxy-based and zinc oxide-eugenol-based sealers.

Objective The purpose of this study was to incorporate EgMA, an antibacterial monomer into two commercial dental adhesive systems for their application in endodontic restoration with the aim to disinfect the root canal space before curing and to inhibit bacterial growth on their surfaces after being cured. Methods EgMA monomer was added at 20% wt. into the formulation of the single-component self-etch, Clearfil Universal Bond™ (CUB) and into the catalyst and the adhesive components of the total-etch Adper Scotchbond-multipurpose™ (SBMP) adhesive systems. The degree of conversion (DC) was calculated from FTIR spectra, glass transition temperature (Tg) determined by DSC, water sorption and solubility were measured gravimetrically, and surface free energy (SFE) via contact angle measurements. The bonding performance to coronal and middle root canal dentin was assessed through push-out bond strength after filling the canals with a composite core material and the surface integrity was observed using SEM and confocal laser scanning microscopy (CLSM). The standard agar diffusion test (ADT) was used to identify the sensitivity of three endodontically pathogenic bacteria, Enterococcus faecalis, Streptococcus mutans and Propionibacterium acnes to uncured EgMA modified adhesives. Multispecies biofilm model from these strains was grown on the disc surface of cured adhesives and investigated using quantitative microbial culture and CLSM with live/dead staining. MTT assay was also used to determine the cytotoxicity of these adhesives. Results The incorporation of EgMA lowered polymerization exotherm and enhanced the hydrophobic character of these adhesives, without changing the DC and Tg in comparison to the controls (without EgMA). The total push-out bond strengths of the EgMA-containing adhesives were not significantly different from those of the controls (p > 0.05). The modification of self-etch adhesive system enhanced the bond strength in the middle region of the roots canal. SEM of debonded specimens and CLSM examination showed the integrity of the resin-dentin interfaces. For all three bacteria tested, the sizes of the inhibition zones produced by uncured EgMA modified adhesives were significantly greater (p < 0.05) than those of the controls. The results of biofilm inhibition tests showed less CFU for total bacteria on bonding agents with EgMA compared to the control materials (p < 0.05). The modification at 20% monomer concentration had no adverse effects on cytocompatibility of both adhesives tested. Significance The inclusion of EgMA endows dental adhesives with effective antibacterial effects without influencing their curing properties, bonding ability to root canal dentin, and cytotoxicity against human gingival fibroblasts, indicating the usefulness of their application in endodontic restorations.

Varicella zoster virus (VZV) is responsible for the primary infection chickenpox. After the initial infection, it remains latent but can reactivate, resulting in shingles (herpes zoster). Previous reports have implicated VZV in the pathogenesis of apical periodontitis, but the involvement of the virus has not been investigated fully. The present case describes a patient who suffered from a severe episode of shingles and subsequently developed periapical radiolucencies of all the teeth in the affected nerve distribution. Molecular and culture techniques showed the presence of VZV DNA in the root canal system in the absence of bacteria. This confirms that VZV can cause localized pulp necrosis and apical periodontitis. The lesions healed after endodontic treatment, implying chemomechanical debridement using sodium hypochlorite irrigation and a calcium hydroxide interim dressing may be effective against the virus.

Aim To investigate the dynamics of a disinfection regimen using 1% trypsin and 1% proteinase K in combination with 2% chlorhexidine (with or without ultrasonics) using a nutrient-stressed endodontic multispecies model biofilm. Methodology Nutrient-stressed biofilms (Propionibacterium acnes, Staphylococcus epidermidis, Actinomyces radicidentis, Streptococcus mitis and Enterococcus faecalis OMGS 3202) were grown in prepared root canals of single-rooted teeth. The treatment groups included 1% trypsin and 2% chlorhexidine (CHX), 1% proteinase K and 2% CHX (with and without ultrasonics). 2% CHX was the positive control and untreated group, and sterile saline (with and without ultrasonics) was the negative control. The biofilms were investigated using confocal laser scanning microscopy (CLSM) with live/dead staining and quantitative microbial culture. Results The trypsin and CHX group with ultrasonics was significantly more effective in reducing viable counts and the substratum coverage than those of all other groups (P

Cherubism is an autosomal dominant disorder that may be related to tooth development and eruption. It is a disorder of age-related bone remodeling, mostly limited to the maxilla and the mandible, with loss of bone in the jaws and its replacement with large amounts of fibrous tissue. We have used a genomewide search with a three-generation family and have established linkage to chromosome 4p16. Three other families affected with cherubism were also genotyped and were mapped to the same locus. The combined LOD score is 4.21 at a recombination fraction of 0, and the locus spans an interval of approximately 22 cM.

The predominant cultivable microbiota from 20 refractory endodontic lesions (9 with abscesses and 11 without abscesses) were determined, and Propionibacterium acnes and Staphylococcus epidermidis were among the most predominant organisms. The number of species identified from lesions with abscesses (14.1 ± 2.6) was significantly greater ( P < 0.001) than the number from lesions without abscesses (7.4 ± 5.9). Comparison of perioral isolates using repetitive extragenic palindromic PCR of the same species from the same subjects demonstrated that the endodontic and skin populations were significantly different. The P. acnes isolates were typed on the basis of recA gene sequence comparison, and only three types (types I, II, and III) were identified among 125 isolates examined. However, we found that type I (type IA and IB) isolates were primarily isolated from the skin, while types II and III were significantly more likely to be isolated from the endodontic lesions ( P < 10 −10 ). We found that the robustness of the recA phylotypes was not strong by comparing the partial gene sequences of six putative virulence determinants, PAmce, PAp60, PA-25957, PA-5541, PA-21293, and PA-4687. The resulting neighbor-joining trees were incongruent, and significant (phi test; P = 2.2 × 10 −7 ) evidence of recombination was demonstrated, with significant phylogenetic heterogeneity being apparent within the clusters. P. acnes and S. epidermidis isolated from refractory endodontic infections, with or without periapical abscesses, are likely to be nosocomial infections.

Bhuva B, Patel S, Wilson R, Niazi S, Beighton D, Mannocci F. The effectiveness of passive ultrasonic irrigation on intraradicular Enterococcus faecalis biofilms in extracted single-rooted human teeth. International Endodontic Journal, 43, 241–250, 2010. Abstract Aim To compare the efficacy of passive ultrasonic irrigation with 1% sodium hypochlorite, with that of conventional syringe irrigation with 1% sodium hypochlorite, on intraradicular Enterococcus faecalis biofilms in extracted single-rooted human teeth. Methodology Biofilms of E. faecalis (strain OMGS 3202) were grown on the prepared root canal walls of 48 standardized root halves which had been longitudinally sectioned. Following reapproximation, the roots were divided into four groups of twelve. The two experimental groups were treated with conventional syringe irrigation with 1% sodium hypochlorite solution (experimental group A) and passive ultrasonic irrigation with 1% sodium hypochlorite solution (experimental group B). Of the two control groups, the first was treated with conventional syringe irrigation with sterile saline solution (control group C), whilst the second control group (D) received no irrigation. The root halves were processed for scanning electron microscopy. Three images (×700), coronal, middle and apical, were taken of the twelve root halves in each of the four groups, using a standardized protocol. The images were randomized and biofilm coverage assessed independently by three calibrated examiners, using a four-point scoring system. Results There were no significant differences in the scores for remaining biofilm coverage between group A (conventional syringe irrigation with 1% sodium hypochlorite) and group B (passive ultrasonic irrigation with 1% sodium hypochlorite) at the three observed levels. There was a significant difference between both experimental groups (groups A and B) and group C (conventional syringe irrigation with sterile saline solution) (P