Chitosan-based endodontic irrigation solutions and TGF-ß1 treatment: Creating the most favourable environment for the survival and proliferation of stem cells of the apical papilla in vitro.

BACKGROUND: The dental pulp's environment is essential for the regulation of mesenchymal stem cells' homeostasis and thus, it is of great importance to evaluate the materials used in regenerative procedures. AIM: To assess in vitro (i) the effect of chitosan nanoparticles, 0.2% chitosan irrigation solution, Dual Rinse®, 17% EDTA, 10% citric acid and 2.5% NaOCl on DSCS viability; (ii) the effect of different concentrations of TGF-ß1 on DCSC proliferation; and (iii) whether treatment with TGF-ß1 following exposure to the different irrigation solutions could compensate for their negative effects. METHODOLOGY: (i) DSCS were treated with three dilutions (1:10, 1:100 and 1:1000) of the six irrigation solutions prepared in DMEM for 10 and 60 min to assess the effect on viability. (ii) The effect of different concentrations (0, 1, 5 and 10 ng/mL) of TGF-ß1 on DCSC proliferation was assessed at 1, 3 and 7 days. (iii) The proliferative effect of TGF-ß1 following 10-min exposure to 1:10 dilution of each irrigation solution was also tested. We used MTT assay to assess viability and proliferation. We performed statistical analysis using Prism software. RESULTS: (i) The different endodontic irrigation solutions tested showed a significant effect on cell viability (p ≤ .0001). Significant interactions between the endodontic irrigation solutions and their dilutions were also found for all parameters (p ≤ .0001). Chitosan nanoparticles and 0.2% chitosan irrigation solution were the least cytotoxic to DSCS whilst 2.5% NaOCl was the most cytotoxic followed by 17% EDTA. (ii) TGF-ß1 at concentrations of 1 and 5 ng/mL resulted in significantly higher proliferation compared to the control group. (iii) Exposure to 17% EDTA or 2.5% NaOCl for 10 min was sufficient to make DSCS cells refractory to the proliferative effects of TGF-ß1. DSCS groups treated with TGF-ß1 following exposure to chitosan nanoparticles, 0.2% chitosan irrigation solution, Dual Rinse® and 10% CA demonstrated significantly higher proliferation compared to non-TGF-ß1-treated groups (p ≤ .0001, p ≤ .0001, p ≤ .0001 and p = .01 respectively). CONCLUSIONS: The current study offers data that can be implemented to improve the outcome of regenerative endodontic procedures by using less toxic irrigation solutions and adding TGF-ß1 to the treatment protocol.

Dental Stem Cells SV40, a new cell line developed in vitro from human stem cells of the apical papilla.

AIM: To establish and fully characterize a new cell line from human stem cells of the apical papilla (SCAPs) through immortalization with an SV40 large T antigen. METHODOLOGY: Human SCAPs were isolated and transfected with an SV40 large T antigen and treated with puromycin to select the infected population. Expression of human mesenchymal surface markers CD73, CD90 and CD105 was assessed in the new cell line named Dental Stem Cells SV40 (DSCS) by flow cytometry at early and late passages. Cell contact inhibition and proliferation were also analysed. To evaluate trilineage differentiation, quantitative polymerase chain reaction and histological staining were performed. RESULTS: DSCS cell flow cytometry confirmed the expression of mesenchymal surface markers even in late passages [100% positive for CD73 and CD90 and 98.9% for CD105 at passage (P) 25]. Fewer than 0.5% were positive for haematopoietic cell markers (CD45 and CD34). DSCS cells also showed increased proliferation when compared to the primary culture after 48 h, with a doubling time of 23.46 h for DSCS cells and 40.31 h for SCAPs, and retained the capacity to grow for >45 passages (150 population doubling) and their spindle-shaped morphology. Trilineage differentiation potential was confirmed through histochemical staining and gene expression of the chondrogenic markers SOX9 and COL2A1, adipogenic markers CEBPA and LPL, and osteogenic markers COL1A1 and ALPL. CONCLUSIONS: The new cell line derived from human SCAPs has multipotency, retains its morphology and expression of mesenchymal surface markers and shows higher proliferative capacity even at late passages (P45). DSCS cells can be used for in vitro study of root development and to achieve a better understanding of the regenerative mechanisms.

A 12-month follow-up of primary and secondary root canal treatment in teeth obturated with a hydraulic sealer.

OBJECTIVES: This randomized, controlled, pilot study assessed the outcome of non-surgical primary/secondary root canal treatments either with a novel bioactive sealer and the single-cone technique or with gutta-percha, zinc oxide-eugenol sealer (ZOE), and warm vertical compaction. MATERIALS AND METHODS: Sixty-nine patients were randomly divided into two groups that were treated using the single-cone technique with BioRootTM RCS (Septodont) (BIO group) or warm vertical compaction with gutta-percha and ZOE sealer (PCS group). Two subsamples (BIOAP and PCSAP) comprised the cases with apical periodontitis. Treatment was undertaken by four residents using a standardized instrumentation and disinfection protocol. The periapical index (PAI) was recorded, and clinical and radiographic follow-up performed at 1, 3, 6, and 12 months. Treatment success was assessed according to "periapical healing" and "tooth survival". The test for the equality of proportions, t tests for the equality of means, and non-parametric K-sample tests for the equality of medians were applied when appropriate. RESULTS: The survival rate was similar in the BIO and PCS (p = 0.4074) and the BIOAP and PCSAP groups (p = 0.9114). The success rate was higher in the BIO groups, but not statistically significant (p = 0.0735). In both BIOAP and PCSAP groups, a progressive decrease in the PAI was observed. CONCLUSION: At 12 months, both techniques showed reliable results. Further studies and longer follow-ups are needed. CLINICAL RELEVANCE: This study documents the feasibility of using a bioactive sealer in conjunction with the single-cone technique to obturate the root canal and obtaining a predictable outcome. TRIAL REGISTRATION: ClinicalTrials.gov Identifie: NCT04249206.

MTA and biodentine for primary teeth pulpotomy: a systematic review and meta-analysis of clinical trials.

OBJECTIVE: This study aims to perform a systematic review and meta-analysis of clinical trials in order to evaluate the clinical and radiographic success rates of primary teeth pulpotomy performed with biodentine, when compared to MTA. METHODS: Search strategies were conducted in nine databases on August 5th, 2017, update on February 14th, 2018. Clinical articles were selected, which were in accordance with the inclusion and exclusion criteria and the research objective. They were analyzed by meta-analysis at three time points (6, 12, and 18 months). RESULTS: Out of the 233 publications initially identified, only 9 studies that fulfilled the inclusion criteria were included in the review. The 6-month overall clinical (RR = 0.99; 95% CI = 0.96-1.02, p = 0.92) and radiographic success rates (RR = 0.96; 95% CI = 0.92-1.00, p = 0.28) showed that biodentine vs. MTA did not differ statistically. The 12 and 18-month overall clinical success rates, respectively (RR = 1.01; 95% CI = 0.97-1.04, p = 0.77; RR = 0.98; 95% CI = 0.92-1.05, p = 0.74) and radiographic success rates, respectively (RR = 0.97; 95% CI = 0.92-1.02, p = 0.11; RR = 1.00; 95% CI = 0.91-1.10, p = 0.56) also showed that biodentine vs. MTA did not differ statistically. CONCLUSION: There is no superiority of one material over the other, MTA versus biodentine. CLINICAL RELEVANCE: This systematic review comparing the performance of biodentine in relation to the MTA when used in the pulpotomy technique in primary teeth. Although MTA is considered the gold standard material for pulpotomy procedures, it has some drawbacks (poor handling, staining potential, long setting time); thus, it is important to evaluate the clinical performance of other calcium silicate-based cements like biodentine that overcome this drawbacks.

Engineering a Microphysiological Model for Regenerative Endodontic Studies.

Dental pulp infections are common buccal diseases. When this happens, endodontic treatments are needed to disinfect and prepare the root canal for subsequent procedures. However, the lack of suitable in vitro models representing the anatomy of an immature root canal hinders research on regenerative events crucial in endodontics, such as regenerative procedures. This study aimed to develop a 3D microphysiological system (MPS) to mimic an immature root canal and assess the cytotoxicity of various irrigating solutions on stem cells. Utilizing the Dental Stem Cells SV40 (DSCS) cell line derived from human apical papilla stem cells, we analyzed the effects of different irrigants, including etidronic acid. The results indicated that irrigating solutions diminished cell viability in 2D cultures and influenced cell adhesion within the microphysiological device. Notably, in our 3D studies in the MPS, 17% EDTA and 9% 1-hydroxyethylidene-1, 1-bisphosphonate (HEBP) irrigating solutions demonstrated superior outcomes in terms of DSCS viability and adherence compared to the control. This study highlights the utility of the developed MPS for translational studies in root canal treatments and suggests comparable efficacy between 9% HEBP and 17% EDTA irrigating solutions, offering potential alternatives for clinical applications.

Update on chelating agents in endodontic treatment: A systematic review.

Background: The aim of this review was to assess the evidence regarding the most commonly used chelating agents in terms of efficacy, erosive potential, cytotoxicity, interaction, antimicrobial effect, impact on sealers adhesion, and release of growth factors. Material and Methods: MEDLINE (PubMed) database, Cochrane Library and Scopus were searched up to January 14, 2023, including studies with one or more of the following chelating agents: 17% EDTA, 9% and 18% HEDP, 10% and 20% citric acid, 2%-2.25% peracetic acid and 7% maleic acid. In addition, the reference lists of all selected articles were also checked to identify additional relevant studies. Articles published in English and available in full-text were selected. The quality of studies was assessed using the modified CONSORT checklist guide and the Cochrane Collaboration tool. Results: The electronic search yielded 538 citations, 56 of which were included. The articles included had moderate and low evidence values. Among 56 articles included, 55 were in vitro studies and one was a randomized clinical trial. Among the in vitro studies, 15 evaluated efficacy and dentin erosion, 12 evaluated interaction with other endodontic irrigants, 9 tested antimicrobial effect, 4 evaluated cytotoxicity in hamster and rat lung cells, 9 evaluated intervention in adhesion of filling materials and 8 focused on release of growth factors and on behavior of stem cells in regenerative endodontic. The RCT tested antimicrobial effect. Conclusions: 17% EDTA is the most effective in smear layer removal and in releasing growth factors on regenerative endodontics. However, the current incorporation of 9% and 18% etidronic acid has shown optimal results due to its compatibility with sodium hypochlorite and its capability on avoiding smear layer formation through a continuous chelation action. Despite these preliminary findings, methodological standardization between studies is required and in vivo studies are necessary to confirm in vitro studies. Key words:Chelating Agents, Smear Layer, Systematic Review, Endodontics, Root Canal Irrigants.

Clinical and radiographic outcomes of the use of four dressing materials in pulpotomized primary molars: a randomized clinical trial with 2-year follow-up.

BACKGROUND: Although multiple materials have been suggested for pulpotomized primary molars, there is no reliable evidence of the superiority of one particular type. AIM: To compare the effectiveness of formocresol (FC), mineral trioxide aggregate (MTA), ferric sulphate, and sodium hypochlorite (NaOCl) as pulp dressing agents in primary molars after 2 years. DESIGN: One hundred primary molars requiring pulp treatment were allocated randomly to the control (FC) and experimental groups (MTA, ferric sulphate, and NaOCl). Clinical and radiographic evaluations were performed at 6, 12, 18, and 24 months. Statistical analysis using Fischer's exact test was performed to determine the significant differences between groups. RESULTS: In the FC and MTA groups, 100% of the available teeth were clinically successful at all follow-up appointments. In the NaOCl group, one clinical failure was found at 18 months, and two clinical failures in the ferric sulphate group were noted at 12 and 24 months, but no significant differences were found among the groups (P = 0.41). No significant differences in radiographic success were found among all the groups at 24 months of follow-up (P = 0.303). CONCLUSIONS: No statistically significant differences among the four materials were found at 24 months suggesting that NaOCl may be an appropriate substitute for FC.

Preorthodontic dilacerated incisive crown modification in a pediatric patient: a case report.

Dental dilacerations are abrupt deviations of the longitudinal axis of the crown or root portion of the tooth, caused by traumatic axial displacement of previously formed hard tissue in relation to the developing soft tissue. CASE PRESENTATION: A 13-year-old boy in good general health was referred for root canal treatment of the maxillary left central incisor, for which abnormal crown morphology impeded orthodontic treatment. He presented bilateral crown dilaceration at both maxillary central incisors. Treatment involved a CAD/CAM milled veneer of the maxillary left central incisor and semidirect warm composite veneer of the maxillary right central incisor. Follow-up and monitoring of the restoration was performed through .stl file analysis. DISCUSSION: Crown dilaceration severity assessment is crucial for deciding the best treatment plan for each case. In this patient, additive restorative protocols, CBCT, and 3D digital model analysis were the most useful aids by providing key multidisciplinary information. CONCLUSION: A multidisciplinary treatment workflow with a minimally invasive approach aided by digital tools such as CBCT and CAD/CAM technologies is useful to achieve successful and predictable outcomes in crown dilaceration cases.

Medium- and Long-Term Re-Treatment of Root Canals Filled with a Calcium Silicate-Based Sealer: An Experimental Ex Vivo Study.

This study investigated the possibility of re-treating a calcium silicate-based sealer (CSBS), compared to an epoxy-resin sealer (RBS), using rotary instrumentation at different times from obturation (1 month/1 year). Thirty-six human mandibular premolars, extracted as a result of orthodontic or periodontal problems, were instrumented and randomly divided into three groups of 12: BR and BR*, which were filled with CSBS and re-treated after one month and one year of storage, respectively, and AH, which was filled with RBS and re-treated after one month. The same re-treatment protocol was used for all teeth, and the times required for the procedure was recorded. The re-treated specimens were longitudinally sectioned and examined at the stereomicroscope (SM) at 20× magnification. Image J Software was used to process the microphotographs. The percentage of residual filling materials in the root canal and the apical third, the ability to reach working length WL and patency, and the time taken to complete the re-treatment were recorded and analyzed by ANOVA and post hoc Bonferroni test (p = 0.05). Scanning electron microscopy (SEM) and coupled energy-dispersive spectroscopy (EDS) were applied to representative samples to evaluate canal cleanliness and chemical elements. Patency and WL were re-established in all of the teeth. Residual filling materials were retained in all specimens of the three groups. The mean percentage of residual materials was significantly different between BR and BR* (p-value = 0.048), with BR* showing the highest values. The mean time to complete re-treatment was significantly lower for AH, followed by BR (p = 0.0001) and BR* (p = 0.0078). Conclusions: After both medium and long storage periods, the CSBS can be concluded to have been successfully removed from canals with simple anatomy.

Does Root Development Status Affect the Outcome of Tooth Autotransplantation? A Systematic Review and Meta-Analysis.

Background: Tooth autotransplantation is defined as the surgical repositioning of an autogenous tooth in another surgical site within the same individual. Aim: The aim of this research was to analyze the outcome of tooth transplantation using immature donor teeth compared with closed apex teeth and to compare differences between donor tooth positions on the arch. Methods: Electronic and manual literature searches were performed in different databases, including the National Library of Medicine (MEDLINE), EMBASE (OVID), Cochrane Central (CENTRAL), and the digital library of the Universitat Internacional de Catalunya (UIC University) from 1978 to March 2021. Studies were selected when they fulfilled the following criteria: only human prospective clinical studies, minimum sample size of 10 patients, minimum follow-up of 1 year, studies reporting or with at least deducible data on survival rates, immediate tooth autotransplantation with completed or incomplete root formation, and publications in the English language. A meta-analysis of random effects was developed to estimate the global effect measure of the survival rate, success rate, and root resorption involving the total sample, as well as open- and closed-apex groups. Results: Twenty-four articles were eligible for analysis. The Cohen's kappa corresponding to this review was 0.87, and the risk assessment was considered low-moderate for the included studies. Overall survival and success rates were 95.9% and 89.4%, respectively, with a mean follow-up of 4 years and an overall mean age of 25.2 ± 12.3 years. Closed apex teeth showed a survival rate of 3.9% lower than that of open apex teeth. Higher complication rates were found for both inflammatory external root resorption and replacement root resorption in the closed-apex group, without reaching statistical significance. Conclusions: Tooth autotransplantation is a viable treatment alternative, regardless of the apical condition, with high survival and success rates after a mean follow-up of 4 years. Open-apex donor teeth could be considered the gold-standard option, showing lower complication rates when compared to closed-apex donor teeth. Future randomized controlled clinical studies are needed to examine the long-term prognosis of this technique.

Horizontal root fracture treated with MTA, a case report with a 10-year follow-up.

Root fractures occur more frequently in fully erupted permanent teeth with closed apices in which the completely formed root is solidly supported in the bone and periodontium. The consequences can be complex because of combined damage to the pulp, dentine, cementum, bone, and periodontium. Management of horizontal root fractures and lateral luxation depends on several factors, with the result that various clinical modalities have been suggested. This case report describes the treatment and 10-year follow-up of two maxillary central incisors, one with horizontal root fracture and the other with lateral luxation, treated with mineral trioxide aggregate and root canal treatment, respectively.

Root Canal Filling Quality Comparison of a Premixed Calcium Silicate Endodontic Sealer and Different Carrier-Based Obturation Systems.

BACKGROUND: The number of voids within the root canal obturation is a relevant parameter to describe the quality of the technique, as well as to predict long-term prognosis. The aim of this study was to evaluate the quality of root canal obturation in curved root canals filled with Thermafil, GuttaCore, GuttaFusion and lateral compaction with AH Plus and EndoSequence BC sealer, by means of percentage of gutta-percha and sealer filled area. METHODS: 200 curved canals of mandibular molars were divided in five groups (n = 40). Each specimen was evaluated at 3, 6 and 9 mm from the apex. A total of 600 samples were analyzed. Obturation was performed with either Thermafil (TH), GuttaCore (GC), GuttaFusion (GF) or lateral compaction (LC), using AH Plus as sealer. In another group EndoSequence BC sealer (BC) was used. Subgroups (n = 20) were made depending on the use of sonic activation during the placement of the sealer. The percentage of total obturation material was analyzed as an indirect measurement of percentage of voids. RESULTS: GF showed a better performance at the apical level, while GC showed the higher percentage of total obturation at the coronal area. No differences were observed for the activation of sealers in any of the groups. Statistical analysis was performed by using two-way ANOVA. Statistical significance was set at CI: 95% (p < 0.05). CONCLUSIONS: Sonic activation of sealers did not show any benefit to avoid the presence of voids within obturation of curved canals. Following the manufacturer recommendations, we found that TH did not show benefits when applied to curved canals.

Guided Endodontics for Managing Severely Calcified Canals.

Endodontic treatment of teeth with pulp canal obliteration presents a challenge given the high likelihood of procedural errors and complications during treatment. These drawbacks can be avoided by using a personalized 3-dimensional (3D) guide designed by overlaying a cone-beam computed tomographic scan with an intraoral scan of the patient. This 3D guide enables the clinician to obtain a straight access to the obliterated root canal.This article described guided endodontics in managing 7 severely obliterated teeth using both virtually designed 3D guides and a customized 1-mm-diameter cylindrical bur. This treatment approach was demonstrated to be safe and fast and can be considered as a predictable technique for the location of calcified canals, thus minimizing complications.

Relationship between internal root resorption and dens in dente.

BACKGROUND: The aim is to report the treatment and follow-up of three lateral incisors with internal root resorption and dens in dente as a possible cause for their development, managed by root canal treatment and apical obturation with MTA or gutta-percha. CASE DESCRIPTION: This case report presents three clinical cases in which dens invaginatus type 2 is shown as a potential cause for the development of internal root resorption. Two cases were filled with a MTA apical plug technique and one with gutta-percha, and all were follow-up through time. PRACTICAL IMPLICATIONS: The incidence of the association of internal root resorption with dens invaginatus may be underestimated and should be studied. Key words:Dens in dente, dens invaginatus, internal root resorption, Mineral Trioxide Aggregate, palatal invagination.

Comparative study of the microtensile bond strength of three different total etch adhesives with different solvents to wet and dry dentin (in vitro test).

The aim of this study was to compare the microtensile bond strength of three different total etch adhesives: XP Bond (Caulk-Dentsply) versus Excite (Ivoclar/Vivadent) and Prime & Bond NT (Caulk-Dentsply). Forty two (42) third human molars were cut to expose the dentinal surface. They were divided into three groups of 14 teeth (GI: XP Bond, G2: Excite, G3: Prime & Bond NT) and two groups of seven teeth for each moisture condition: moist dentin (GM) and dry dentin, (GD). The total-etch technique was used with each moisture variation. The adhesives and composites A3 (Ceram Duo GI, G3 and Tetric Ceram G2) were applied according to manufacturer's instructions. Teeth were cut with an ISOMET 1000 (Buehler Ltd.) to obtain 1 mm2 x 10 mm bars, which were subject to a traction test at 5 mm/min in a universal testing machine (Adamel Lhomargy DY 36). The collected data were recorded and analyzed using an experimental design for studying two factors offixed effrcts with software Statgraphics version 5.1. For the variable type of adhesive, we found p = 0.000, for the variable substrate condition, p = 0.0012, and for interaction between both factors, p = 0.0457, which indicates significant statistical differences. The values for microtensile bond strength were G1M = 55.0642 MPa Standard deviation (SD) 3.09768; G1D 39.115 MPa SD 2.86789; G2M 34.1607 MPa SD 2.86789; G2D = 32.7373 MPa SD 2.77065; G3M 3 7.3407 MPa SD 2.86789 and G3D = 31.0593 MPa SD 2.77065. XP Bond showed the greatest values of micmtensile bond strength under both conditions. Moist substrate increases the values of micmtensile bond stren gth]br the adhesives tested; howeve, Excite shows lower susceptibility to variation of dentinal moisture.

Efficacy of sonic and ultrasonic irrigation devices in the removal of debris from canal irregularities in artificial root canals.

OBJECTIVE: To evaluate the efficacy of different sonic and ultrasonic devices in the elimination of debris from canal irregularities in artificial root canals. MATERIALS AND METHODS: A resin model of a transparent radicular canal filled with dentin debris was used. Five groups were tested, namely: Group 1 - ultrasonic insert 15.02; Group 2 - ultrasonic insert 25/25 IRRI K; Group 3 - ultrasonic insert 25/25 IRRI S; Group 4 - sonic insert 20/28 Eddy on a vibrating sonic air-scaler handpiece; Group 5 - 20.02 K-file inserted on a Safety M4 handpiece. Two different irrigants (5% sodium hypochlorite and 17% EDTA) and 3 different times of activation (20, 40, and 60 seconds) were tested. Means and standard deviations were calculated and statistically analyzed with the Kruskal-Wallis and Wilcoxon tests (p<0.05). RESULTS: No statistically significant differences were found between the two irrigants used. Group 4 removed more debris than the other groups (p<0.05). Groups 1, 2, and 3 removed more debris than group 5 (p<0.05). A statistically significant difference (p<0.05) was found for the time of activation in all groups and at all canal levels, except between 40 and 60 seconds in group 4 at coronal and middle third level (p>0.05). CONCLUSIONS: No significant differences were found between 5% sodium hypochlorite and 17% EDTA. When the time of activation rises, the dentin debris removal increases in all groups. Both sonic and ultrasonic activation demonstrate high capacity for dentin debris removal.

Comparison of PathFile and ProFinder Systems to Create a Glide Path in Curved Root Canals.

OBJECTIVE: Root canal shaping is as important as irrigation and filling when attempting to obtain a high success rate in endodontic treatment. The creation of a glide path before the use of rotary instruments reduces the risk of posterior iatrogenic errors. The objective of the present study was to evaluate instrumentation time and root canal transport after using 2 different glide path rotary systems. METHODS: In total, 60 mesiobuccal root canals of mandibular molars, with curvature angles between 11° and 82°, were standardized to measure 15 mm. The specimens were divided into 2 groups, depending on their angles of curvature (11º-38º and 39º-82º), and further divided into 4 groups (n=15). Two groups were instrumented using the PathFile system and the other 2 using the ProFinder system. The angle and radius of curvature were measured at the most abrupt angle of curvature before and after instrumentation. Both measurements were analyzed and compared using AutoCAD software to determine canal transportation. Curvature angles were compared using Student's t test and the radii of curvature using the Wilcoxon test. The time for instrumentation was also evaluated using Student's t tests. RESULTS: There were no statistically significant differences between the two systems with respect to root canal transport (P>0.05); however, the ProFinder system took a longer time to create a glide path (P=0.004). CONCLUSION: Both systems were equally effective in creating a glide path; however, the PathFile system proved to be faster than the ProFinder system.

Double acid etching treatment of dental implants for enhanced biological properties.

BACKGROUND: The topographical features on the surface of dental implants have been considered as a critical parameter for enhancing the osseointegration of implants. In this work, we proposed a surface obtained by a combination of shot blasting and double acid etching. The double acid etching was hypothesized to increase the submicron topography and hence further stimulate the biological properties of the titanium implant. METHODS: The topographical features (surface roughness and real surface area), wettability and surface chemical composition were analyzed. RESULTS: The results showed that the proposed method produced a dual roughness, mainly composed of randomly distributed peaks and valleys with a superimposed nanoroughness, and hence with an increased specific surface area. Despite the fact that the proposed method does not introduce significant chemical changes, this treatment combination slightly increased the amount of titanium available on the surface, reducing potential surface contaminants. Furthermore, the surface showed increased contact angle values demonstrating an enhanced hydrophobicity on the surface. The biological behavior of the implants was then assessed by culturing osteoblast-like cells on the surface, showing enhanced osteoblast adhesion, proliferation and differentiation on the novel surface. CONCLUSIONS: Based on these results, the described surface with dual roughness obtained by double acid etching may be a novel route to obtain key features on the surface to enhance the osseointegration of the implant. Our approach is a simple method to obtain a dual roughness that mimics the bone structure modified by osteoclasts and increases surface area, which enhances osseointegration of dental implants.

Evaluation of the WaveOne Gold and One Shape New Generation in Reducing Enterococcus faecalis from Root Canal.

The aim of this study was to evaluate the WaveOne Gold and One Shape New Generation systems regarding the bacterial removal from root canals infected with Enterococcus faecalis by comparing them to the conventional WaveOne and One Shape systems. Forty-eight distobuccal root canals of maxillary molars sterilized with ethylene oxide were infected with E. faecalis for 21 days, and then root canal initial bacterial sample was collected with paper cones and plated on M-enterococcus agar. The specimens were randomly divided into 4 groups according to the instrumentation: WaveOne Gold, One Shape New Generation, WaveOne and One Shape. After instrumentation, samples were collected with use of scraping and paper cones at immediate and 7 days after instrumentation. The bacterial reduction was calculated and then made intragroup analysis by Friedman test and intergroup analysis by Kruskal-Wallis with Dunn's post-hoc test, all at 5% significance. All techniques significantly reduced the number of bacteria in the root canal (p<0.05). WaveOne Gold and One Shape New Generation promoted higher bacterial reduction than WaveOne and One Shape systems (p<0.05), but no significant difference was found between WaveOne Gold and One Shape New Generation or between WaveOne and One Shape (p>0.05). Novel single-file systems promote better bacterial removal than the conventional single-file systems.