Showing papers in "International Endodontic Journal in 2017"

A new system for classifying root and root canal morphology

Abstract: Knowledge of root and root canal morphology is a prerequisite for effective nonsurgical and surgical endodontic treatments. The external and internal morphological features of roots are variable and complex, and several classifications have been proposed to define the various types of canal configurations that occur commonly. More recently, improvements in nondestructive digital image systems, such as cone-beam and micro-computed tomography, as well as the use of magnification in clinical practice, have increased the number of reports on complex root canal anatomy. Importantly, using these newer techniques, it has become apparent that it is not possible to classify many root canal configurations using the existing systems. The purpose of this article is to introduce a new classification system that can be adapted to categorize root and root canal configurations in an accurate, simple and reliable manner that can be used in research, clinical practice and training.

Ex vivo evaluation of four final irrigation protocols on the removal of hard‐tissue debris from the mesial root canal system of mandibular first molars

Abstract: Aim To evaluate the efficacy of four final irrigation protocols on the reduction of hard-tissue debris accumulated within the mesial root canal system of mandibular first molars using micro-CT analysis. Methodology Forty mesial roots of mandibular molars with a single and continuous isthmus connecting the mesiobuccal and mesiolingual canals (Vertucci's Type I configuration) were selected and scanned at a resolution of 8.6 μm. Canals were enlarged sequentially using WaveOne Small and Primary instruments activated in reciprocating motion without intracanal irrigation to allow debris to accumulate within the mesial root canal system. Then, specimens were anatomically matched and distributed into four groups (n = 10), according to the final irrigation protocol: apical positive pressure (APP), passive ultrasonic irrigation (PUI), Self-adjusting File (SAF) and XP-endo Finisher (XPF). The final irrigation procedures were performed over 2 min using a total of 5.5 mL of 2.5% NaOCl per canal. Reconstructed data sets were coregistered, and the mean percentage reduction of accumulated hard-tissue debris after the final irrigation procedures was compared statistically between groups using the anovapost hoc Tukey test with a significance level set at 5%. Results Reduction of accumulated hard-tissue debris was observed in all groups after the final irrigation protocol. Overall, PUI and XPF groups had higher mean percentage reductions of accumulated hard-tissue debris (94.1% and 89.7%, respectively) than APP and SAF groups (45.7% and 41.3%, respectively) (P 0.05) or APP and SAF groups (P > 0.05). Conclusions The PUI technique and XP-endo Finisher instrument were associated with significantly lower levels of AHTD compared with conventional irrigation and the modified SAF system protocol in mesial root canals of mandibular molars.

Minimally invasive endodontics: a new diagnostic system for assessing pulpitis and subsequent treatment needs

Abstract: Developments in our understanding of pulp biology and the response of the pulp to the release of dentine-bound bioactive growth factors have highlighted that the pulp in mature teeth has a greater regenerative capacity than previously thought. Preserving all or part of the pulp is beneficial as it is less invasive than conventional root canal treatment. It retains the biological immune response and could help prevent infection of the periapical tissues. Recent correlations between histological findings and corresponding clinical signs, symptoms and tests can be used to carefully differentiate between different stages of reversible and irreversible pulpitis. In addition, it has become evident that if the correct vital pulp treatment is employed, pulp tissue previously diagnosed as irreversibly inflamed can at least be partially maintained. This highlights a problem with the existing diagnostic classification system in that the use of the term “irreversible” is misleading. Therefore, the aim of this communication is to both introduce a new way of diagnosing the various stages of pulpitis and also to relate the diagnosis to alternative minimal invasive treatment choices based on the degree of pulpal inflammation. Aim: To introduce a new way of thinking about the inflamed pulp. We want to highlight that there is reversibly inflamed tissue in pulps that are currently diagnosed as irreversibly inflamed. This implies that the currently employed terminology may not reflect the actual inflammatory status of pulps evaluated clinically. We therefore propose and introduce a new diagnostic system with new terminology to highlight the healing potential of the pulp. This also implies that current treatment strategies are evaluated and revised to maintain pulp vitality with associated benefits.

Antibiotics in Endodontics: a review

Abstract: The overuse of antibiotics and the emergence of antibiotic-resistant bacterial strains is a global concern. This concern is also of importance in terms of the oral microbiota and the use of antibiotics to deal with oral and dental infections. The aim of this paper was to review the current literature on the indications and use of antibiotics and to make recommendations for their prescription in endodontic patients. Odontogenic infections, including endodontic infections, are polymicrobial, and in most cases, the prescription of antibiotics is empirical. This has led to the increasing use of broad-spectrum antibiotics even in cases where antibiotics are not indicated, such as symptomatic irreversible pulpitis, necrotic pulps and localized acute apical abscesses. In case of discrete and localized swelling, the primary aim is to achieve drainage without additional antibiotics. Adjunctive antibiotic treatment may be necessary in the prevention of the spread of infection, in acute apical abscesses with systemic involvement and in progressive and persistent infections. Medically compromised patients are more susceptible to complication arising from odontogenic infections and antimicrobials have a more specific role in their treatment. Therefore, antibiotics should be considered in patients having systemic diseases with compromised immunity or in patients with a localized congenital or acquired altered defence capacity, such as patients with infective endocarditis, prosthetic cardiac valves or recent prosthetic joint replacement. Penicillin VK, possibly combined with metronidazole to cover anaerobic strains, is still effective in most cases. However, amoxicillin (alone or together with clavulanic acid) is recommended because of better absorption and lower risk of side effects. In case of confirmed penicillin allergy, lincosamides such as clindamycin are the drug of choice.

Properties of BioRoot RCS, a tricalcium silicate endodontic sealer modified with povidone and polycarboxylate

Abstract: Aim To evaluate the chemical and physical properties of a tricalcium silicate root canal sealer containing povidone and polycarboxylate (BioRoot RCS), a calcium silicate MTA based sealer containing a salicylate resin (MTA Fillapex), a traditional eugenol-containing sealer (Pulp Canal Sealer) and an epoxy resin-based root canal sealer (AH Plus). Methodology Calcium release, pH, setting time, water sorption, (volume of open pores, volume of impervious portion, apparent porosity) porosity and weight loss were measured. The ability to nucleate calcium phosphates (CaP) after ageing 28 days in a simulated body fluid was evaluated using ESEM-EDX and micro-Raman spectroscopy. Data were statistically analyzed (p=0.05) using one-way ANOVA (setting time, radiopacity, solubility, water sorption, porosity) or two-way ANOVA (ion release tests). Results BioRoot RCS had a final setting time of 300 min and adequate radiopacity (5.2 mmAl). It demonstrated the highest (p<0.05) and more prolonged ability to release calcium ions (721 ppm at 3h) and to increase the pH (11-12) (p<0.05); B-type carbonated apatite deposits were found on aged BioRoot RCS (biointeractivity-related CaP-forming ability). A final setting time of 270 min and good calcium release (17.4 ppm at 3h) were measured for MTA Fillapex; apatite deposits were present on aged samples. No calcium release and no alkalizing activity were measured for Pulp Canal Sealer and AH Plus; no CaP nucleation was detected on aged Pulp Canal Sealer, and some apatite deposits were found on aged AH Plus (chemi/physisorption-related CaP-deposition). Higher and significantly different (p<0.05) porosity, water sorption and solubility were measured for the two calcium silicate sealers, especially for BioRoot RCS. Conclusions BioRoot RCS had bioactivity with calcium release, strong alkalizing activity and apatite forming ability, adequate radiopacity. This article is protected by copyright. All rights reserved.

Assessment of Mineral Trioxide Aggregate pulpotomy in mature permanent teeth with carious exposures

Abstract: Aim To assess the outcome of mineral trioxide aggregate (MTA) complete pulpotomy in permanent teeth with carious exposures. Methodology Fifty-two permanent molar teeth with fully developed roots and vital pulps in 43 patients aged 11–51 years were included. Preoperative pulpal and periapical diagnosis was established. After informed consent, each tooth was anaesthetized, isolated with dental dam and disinfected with 5% NaOCl before caries excavation; subsequently, a full pulpotomy was performed. Haemostasis was achieved, and Grey MTA (Angelus, Londrina, Brazil) was placed as the pulpotomy agent; a moist cotton pellet was placed, and the tooth was temporized with the intermediate restorative material (IRM). Permanent restorations were placed 1 week later if the tooth was asymptomatic, and a postoperative periapical radiograph was taken. Clinical and radiographic evaluation was completed at 3 months, 6 months, 1 year and 3 years postoperatively. Results Clinical signs and symptoms suggestive of irreversible pulpitis were established in 44/52 teeth, and periapical rarefaction was present in 14 teeth. Immediate failure occurred in one tooth. The recall rate ranged from 92% at 3 months to 80.3% at 3 years, with an overall 100% clinical and 97.5% radiographic success during the first year, and 92.7% success at 3 years. All cases with periapical rarefaction were associated with improvement in the periapical index (PAI) score. Two cases had new periapical rarefaction associated with dislodgment of the permanent restoration. A hard tissue barrier was detected radiographically in 5 cases and canal narrowing in 7 cases. Conclusion MTA full pulpotomy was a successful treatment option for cariously exposed pulps in mature permanent molar teeth.

Comparative accuracy of the Clearing Technique, CBCT and Micro-CT methods in studying the mesial root canal configuration of mandibular first molars

Abstract: AIMS To compare the accuracy of the clearing technique and cone beam computed tomography (CBCT) in the assessment of root canal configurations using micro-computed tomography (micro-CT) imaging system as the reference standard. METHODOLOGY Thirty-two mesial roots of mandibular first molars, selected on the basis of micro-CT scans (voxel size: 19.6 μm) and presenting several canal configurations, were evaluated using 2 CBCT scanners (voxels sizes: 120 μm and 150 μm) followed by the clearing technique. Two examiners analysed the data from each method and classified the anatomical configuration of the mesial canal according to Vertucci's system. Data were compared using Fisher's exact and chi-square tests. Reliability for each assessment was verified by the kappa test, and significance level was set at 5%. RESULTS Kappa value indicated a high level of agreement between the examiners. Detection of type I configurations was significantly lower in cleared teeth (P 0.05). In mesial roots with variable anatomical configurations, CBCT and the clearing method were significantly less accurate than the reference standard (P < 0.05). CONCLUSION Within the tooth population studied, accuracy of identifying mesial root canal configuration was influenced greatly by the evaluation method and the type of anatomy. Detection of type I configurations in cleared teeth was significantly lower, whilst type II configurations were detected in all specimens by both methods. In mesial roots with variable anatomical configurations, neither CBCT nor clearing methods were accurate for detecting the actual root canal anatomy.

Root and root canal morphology of the permanent dentition in a Caucasian population: a cone-beam computed tomography study.

Abstract: Aim To investigate in vivo the number of roots, the root canal system configuration and the root canal splitting and merging levels in the permanent dentition of a Caucasian population. Methodology A total of 11,892 teeth were inspected in Cone Beam Computed Tomography examinations that were collected from a pre-existing database. The number of roots was identified, and canal configurations were classified according to Vertucci's classification and its supplemental configurations. In addition, the merging and separation positions along the length of the root canal were identified. The Z-test was used to analyse the differences between independent groups. A value of p<0.05 was considered significant. Results The majority of tooth types had considerable variation in the number of roots and root canal configuration types. Radix entomolaris and paramolaris were rare occurrences. The mesiobuccal root of the maxillary first and second molars had two root canals in 71% and 44% of the cases, respectively. Nearly 30% of the mandibular incisors had two root canals. Root canal merging and splitting appeared more often in mandibular teeth. Merging was more common in the middle third of the root canal in the maxillary teeth and in the middle and apical thirds in mandibular teeth. Root canal splitting did not exhibit a tendency, and their position along the length of the root canal varied from tooth to tooth. Conclusion Clinicians must be aware that each tooth may display several types of root canal configuration. However, a greater variability in root canal configuration was found in maxillary second premolars and in the mesiobuccal roots of maxillary molars. Main root canal merging and splitting may also be expected to occur at any level of the root canal. This article is protected by copyright. All rights reserved.

Pulp sensibility and vitality tests for diagnosing pulpal health in permanent teeth: a critical review.

Abstract: The aim of this review was to critically appraise the literature related to pulp vitality and sensibility testing in order to determine the diagnostic accuracy of pulp tests with reference to a gold standard or control group. Implications of the results for research and clinical practice are also explored. The MEDLINE (Ovid), MEDLINE (PubMed), Embase and Cochrane databases were searched for English-language clinical trials in humans in which in vivo studies were designed to evaluate or compare the accuracy of selected pulp sensibility and pulp vitality tests in determining the state of pulpal health in permanent teeth. Studies were included only if the results were compared to a control group or to a valid gold or reference standard. Eight studies were identified. Shortcomings in research design were found to influence the findings. The limited number of studies investigating pulp vitality tests was insufficient to answer the research question. It was concluded from this critical appraisal of the literature that laser Doppler flowmetry appeared to be the most accurate method for diagnosing the state of pulpal health and came closest to serving as a gold standard. Pulp vitality tests proved superior to pulp sensibility tests for early and accurate assessments of the pulpal health of traumatized teeth. When accurately used and interpreted, pulp sensibility tests provide valuable diagnostic information, particularly when an electric pulp test is used in combination with either CO2 snow or Endo-Ice.

Movement kinematics and cyclic fatigue of NiTi rotary instruments: a systematic review.

Abstract: The aim of this review was to provide a detailed analysis of the literature concerning the correlation between different movement kinematics and the cyclic fatigue resistance of NiTi rotary endodontic instruments. From June 2014 to August 2015, four independent reviewers comprehensively and systematically searched the Medline (PubMed), EMBASE, Web of Science, Scopus and Google Scholar databases for works published since January 2005, using the following search terms: endodontics; nickel-titanium rotary files; continuous rotation; reciprocating motion; cyclic fatigue. In addition to the electronic searches, manual searches were performed to include articles listed in the reference sections of high-impact published articles that were not indexed in the databases. Laboratory studies in English language were considered for this review. The electronic and manual searches resulted in identification of 75 articles. Based on the inclusion criteria, 32 articles were selected for analysis of full-text copies. Specific analysis was then made of 20 articles that described the effects of reciprocating and continuous movements on cyclic fatigue of the instruments. A wide range of testing conditions and methodologies have been used to compare the cyclic fatigue resistance of rotary endodontic instruments. Most studies report that reciprocating motion improves the fatigue resistance of endodontic instruments, compared to continuous rotation, independent of other variables such as the speed of rotation, the angle or radius of curvature of simulated canals, geometry and taper, or the surface characteristics of the NiTi instruments.

Capping carious exposures in adults: a randomized controlled trial investigating mineral trioxide aggregate versus calcium hydroxide.

Abstract: Aim The aim of this multicentre, parallel-group randomized clinical trial was to compare the effectiveness of mineral trioxide aggregate (MTA) and a conventional calcium hydroxide liner (CH) as direct pulp capping materials in adult molars with carious pulpal exposure. Methodology Seventy adults aged 18 to 55 years were randomly allocated to two parallel arms: MTA (White ProRoot, Dentsply, Tulsa Dental, Tulsa, OK, USA) (n=33) and CH (Dycal®, Dentsply DeTrey GmbH, Konstanz, Germany) (n=37). The teeth were temporized for one week with glass ionomer (Fuji IX, GC Corp, Tokyo, Japan), and then permanently restored with a composite resin. The subjects were followed up after 1 week and at 6, 12, 24, and 36 months. The primary outcome was the survival of the capped pulps, and the secondary outcome was postoperative pain after 1 week. Survival was defined as a non-symptomatic tooth that responded to sensibility testing and did not exhibit periapical changes on radiograph. At each check-up, the pulp was tested for sensibility and a periapical radiograph was taken (excluding the radiographs taken at the 1-week follow up). Kaplan-Meier survival analysis and log-rank test was used to assess the significant difference in the survival curves between groups. Chi-square test was used to assess the association between the materials and preoperative and postoperative pain. Results At 36 months, the Kaplan-Meier survival analysis showed a cumulative estimate rate of 85% for the MTA group and 52% for the CH group (p=0.006). There was no significant association between the capping material and postoperative pain. Conclusions MTA performed more effectively than a conventional CH liner as a direct pulp capping material in molars with carious pulpal exposure in adult patients. This study has been registered at ClinicalTrials. gov, number NCT01224925. This article is protected by copyright. All rights reserved.

Diagnostic accuracy of periapical radiography and cone beam computed tomography in detecting apical periodontitis using histopathological findings as a reference standard.

Abstract: Aim To compare the diagnostic accuracy of periapical radiography (PR) and cone beam computed tomography (CBCT) in detecting apical periodontitis (AP) using histopathological findings as a reference standard. Methodology Jaw sections containing 67 teeth (86 roots) were collected from unclaimed bodies due for cremation. Imaging was carried out to detect AP by digital PR with a central view (DP group), digital PR combining central with 10˚ mesially and distally angled (parallax) views (DPS group) and CBCT scans. All specimens underwent histopathological examination to confirm the diagnosis of AP. Sensitivity, specificity and predictive values of PR and CBCT were analysed using rater mean (n = 5). Receiver-operating characteristic (ROC) analysis was carried out. Results Sensitivity was 0.27, 0.38 and 0.89 for DP, DPS and CBCT scans, respectively. CBCT had specificity and positive predictive value of 1.0 whilst DP and DPS had specificity and positive predictive value of 0.99. The negative predictive value was 0.39, 0.44 and 0.81 for DP, DPS and CBCT scans, respectively. Area under the curve (AUC) for the various imaging methods was 0.629 (DP), 0.688 (DPS), and 0.943 (CBCT). Conclusions All imaging techniques had similar specificity and positive predictive values. Additional parallax views increased the diagnostic accuracy of PR. CBCT had significantly higher diagnostic accuracy in detecting AP compared to PR, using human histopathological findings as a reference standard.

Laboratory comparison of cyclic fatigue resistance of WaveOne Gold, Reciproc and WaveOne files in canals with a double curvature.

Abstract: Aim To compare the resistance to cyclic fatigue of WaveOne Gold (WOG), Reciproc and WaveOne (WO) nickel–titanium files in an artificial root canal with a double (S-shaped) curvature. Methodology A total of 120 new WOG primary, Reciproc R25 and WO primary files were tested in an artificial, stainless steel canal with an S-shape (diameter, 1.4 mm and length, 18 mm). Forty files from each system were rotated until fracture to calculate the number of cycles to failure (NCF). The length of each fractured fragment was recorded. Data were analysed using one-way analysis of variance and Tukey's post hoc tests. Results The WOG primary (apical curvature: 928.87 ± 293.69; coronal curvature 1102.32 ±397.39 NCF) had higher cyclic fatigue resistance than Reciproc R25 and WO primary in the apical and coronal curvatures (P 0.05). There was no difference in fractured fragment lengths of the WOG primary, Reciproc R25, and WO primary files in either the apical or coronal curvature (P > 0.05). Conclusions WaveOne Gold primary files exhibited greater cyclic fatigue resistance than Reciproc R25 and WO primary in an artificial canal with an S-shape.

Evaluation of cytocompatibility of calcium silicate-based endodontic sealers and their effects on the biological responses of mesenchymal dental stem cells.

Abstract: Aim To investigate in vitro the cytocompatibility of the calcium silicate-containing endodontic sealers MTA Fillapex and TotalFill BC Sealer on human periodontal ligament stem cells (hPDLSCs) by assaying their biological responses and compare them with that observed when using an epoxy resin-based sealer (AH Plus). Methodology Specimens from the three different endodontic sealers were eluated with culture medium for 24 h. The cytotoxicity of these eluates was evaluated using the MTT assay. In addition, an in vitro scratch wound healing model was used to determine their effects on cell migration. Cell adhesion to collagen type I after treatment with the different sealer eluates was also measured, whereas cytotoxicity was determined using the DNA-specific fluorochrome Hoechst 33342. Finally, to assess cell morphology and attachment to the different sealers, hPDLSCs were directly seeded onto the material surfaces and analysed by scanning electron microscopy (SEM). One-way analysis of variance (anova) followed by a Bonferroni post-test were performed (P < 0.05). Results hPDLSCs exposed to different dilutions of TotalFill BC Sealer eluates had significantly higher cell proliferation compared with that observed when cells were treated with AH Plus and MTA Fillapex eluates (P < 0.001). In addition, TotalFill eluates were associated with significantly increased cell adhesion to collagen type I and migration of hPDLSCs in a concentration-dependent manner than displayed after treatment with MTA Fillapex or AH Plus eluates (P < 0.001). Moreover, TotalFill BC Sealer-induced cytotoxicity was significantly lower than observed using AH Plus and MTA Fillapex eluates (P < 0.001). Finally, SEM studies revealed suitable proliferation, cell spreading and attachment, especially when using TotalFill BC Sealer discs. Conclusion TotalFill BC Sealer exhibited a higher cytocompatibility than AH Plus and MTA Fillapex. Further investigations using in vivo animal models are required to validate the potential biological responses of TotalFill BC Sealer on hPDLSCs.

Cytotoxicity and bioactivity of various pulpotomy materials on stem cells from human exfoliated primary teeth

Abstract: Aims To investigate the cytotoxicity and bioactivity of several pulpotomy materials: Biodentine (Septodont, Saint-Maur-des-Fosses, France) MTA (Angelus, Londrina, PR, Brazil), Theracal LC (Bisco Inc., Schamburg, IL, USA) and IRM (Dentsply DeTrey GmbH, Konstanz, Germany), after contact with stem cells isolated from human exfoliated primary teeth (SHEDs). Methodology SHEDs were cultured in the presence of the eluates of various pulpotomy materials for 24, 48 and 72 h. Cell viability was determined by mitochondrial dehydrogenase enzymatic (MTT) assay. Apoptosis and changes in cell phenotype were evaluated by flow cytometry. Also, an in vitro scratch wound-healing assay was used to determine their effects on cell migration. To assess cell morphology and attachment to the different pulpotomy materials, SHEDs were directly seeded onto the material surfaces and analysed by scanning electron microscopy (SEM). Finally, the deposition of a calcified matrix in presence of these materials was verified by Alizarin Red staining. Statistical analysis was performed with analysis of variance and Bonferroni or Tukey post-test (α = 0.05). Results Cell viability in the presence of Biodentine eluates was significantly higher to that obtained using complete medium alone (control; P < 0.01) and was also significantly higher than using MTA Angelus from 48 h of incubation (P < 0.01). However, Theracal LC and IRM were associated with low rates of cell viability (P < 0.001). Similar results were obtained in an apoptosis assay. In addition, SHEDs maintained their mesenchymal phenotype in all conditions although their capacity to migrate was higher in the presence of Biodentine. SEM studies revealed a suitable proliferation rate, cell spreading and attachment, especially when using Biodentine and MTA Angelus discs. Finally, Biodentine eluates significantly induced calcified matrix deposition from 7 days of culture (P < 0.01). Conclusions Biodentine exhibited better cytocompatibility and bioactivity than MTA Angelus, Theracal LC and IRM.

Association between apical periodontitis and cardiovascular diseases: a systematic review of the literature.

Abstract: A systematic review was conducted to assess the association between apical periodontitis (AP) and cardiovascular disease (CVD). Studies published from the earliest date available until September 2015 were retrieved from the Medline, PubMed and Embase databases. The included studies reported the results from observational studies and assessed the link between AP and CVD as confirmed by one of the following criteria: diagnosed coronary artery disease, angina pectoris, acute myocardial infarction, stroke or mortality caused by cardiac pathology. The study characteristics were abstracted by independent researchers following the PRISMA standard protocol. NOS criteria were used to rate the quality of the studies, and the GRADE was used for level of evidence evaluation. Nineteen epidemiological studies fulfilled the predetermined inclusion criteria: 10 case-control studies, five cross-sectional studies and four cohort studies. There was considerable heterogeneity amongst the included studies in terms of their study design, population, outcomes of interest and AP evaluation methods. Considering the limited availability and the heterogeneity amongst the studies, meta-analysis was not attempted. Thirteen of the 19 included studies found a significant positive association between apical periodontitis and cardiovascular disease, although in two of them, the significance was present only in univariate analysis. Five studies failed to reveal positive significance, and one study reported a negative association. In conclusion, although most of the published studies found a positive association between apical periodontitis and cardiovascular disease, the quality of the existing evidence is moderate-low and a causal relationship cannot be established.

Bioactivity of MTA Plus, Biodentine and an experimental calcium silicate-based cement on human osteoblast-like cells.

Abstract: AIM To compare the bioactivity of Biodentine (BIO, Septodont), MTA Plus (MTA P, Avalon) and calcium silicate experimental cement (CSC) with resin (CSCR) associated with zirconium (CSCR ZrO2 ) or niobium (CSCR Nb2 O5 ) oxide as radiopacifiers. METHODOLOGY According to the relevance of osteoblastic cell response for mineralized tissue repair, human osteoblastic cells (Saos-2) were exposed to test materials and assessed for viability (MTT), cell proliferation, gene expression of alkaline phosphatase (ALP) osteogenic marker by real-time PCR (RT-qPCR), ALP activity assay and alizarin red staining (ARS) to detect mineralization nodule deposition in osteogenic medium. Unexposed cells acted as the control group (C). Statistical analysis was carried out using ANOVA and the Bonferroni post-test (P < 0.05). RESULTS All tested cements showed dose-dependent responses in cell viability (MTT). Exposed cells revealed good viability (80-130% compared to the control group) in the highest dilutions of all types of cement. MTA P, BIO and CSCR ZrO2 significantly increased the velocity of cell proliferation after three days of cell exposure in the wound-healing assay (P < 0.05), which corroborated MTT data. On day 3, the ALP transcript level increased, especially to CSCR Nb2 O5 (P < 0.05). All cements exhibited suitable ALP enzyme activity, highlighting the 7-day period of cell exposure. ARS, CSCR Nb2 O5 , revealed a significant potential to induce mineralization in vitro. CONCLUSIONS All materials had suitable biocompatibility and bioactivity. The MTA P, BIO and CSCR ZrO2 groups had the highest viability rates and velocity of proliferation whilst the CSCR Nb2 O5 group produced more mineralized nodules.

Structural analysis of HyFlex EDM instruments.

Abstract: Aim To compare the phase transformation behaviour, the microstructure, the nano-hardness and the surface chemistry of electro-discharge machined HyFlex EDM instruments with conventionally manufactured HyFlex CM. Methodology New and laboratory used HyFlex EDM were examined by X-ray diffraction (XRD) and differential scanning calorimetry (DSC). Nano-hardness and modulus of elasticity were also investigated using a maximum load of 20 mN with a minimum of 40 significant indentations for each sample. Raman spectroscopy and field emission-scanning electron microscope (FE-SEM) were used to assess the surface chemistry of HyFlex EDM. HyFlex CM were subjected to the same investigations and used as a comparison. Nano-indentation data were statistically analysed using the Student's t-test. Results XRD analysis on HyFlex EDM revealed the presence of martensite and rhombohedral R-phase, while a mixture of martensite and austenite structure was identified in HyFlex CM. DSC analysis also disclosed higher austenite finish (Af) temperatures for electro-discharge machining (EDM) instruments. Significant differences in nano-hardness and modulus of elasticity were found between EDM and CM files (P < 0.05). FE-SEM and EDS analyses confirmed that both new EDM and CM files were covered by an oxide layer. Micro-Raman spectroscopy assessed the presence of rutile-TiO2 . Conclusions HyFlex EDM revealed peculiar structural properties, such as increased phase transformation temperatures and hardness. Present results corroborated previous findings and shed light on the enhanced mechanical behaviour of these instruments.

Mineral trioxide aggregate pulpotomy for permanent molars with clinical signs indicative of irreversible pulpitis: a preliminary study.

Abstract: Aim To prospectively investigate the clinical and radiographic success rates of pulpotomy in permanent molars with clinical signs and symptoms suggestive of irreversible pulpitis using mineral trioxide aggregate (MTA) as a pulp dressing agent. Methodology Sixteen patients with 23 restorable permanent molars exhibiting signs and symptoms indicative of irreversible pulpitis were enrolled. A standardized operative procedure was followed for all participants. All teeth were isolated with a dental dam and caries was removed, and then, pulpotomy performed with a sterile round and/or flame shape diamond burs. Haemostasis was achieved with 5% sodium hypochlorite (NaOCl). A mixture of MTA was placed against the wound, and a moistened cotton pellet was placed over the MTA. Teeth were temporized with a glass–ionomer restoration. Three to ten days later, the interim restoration was removed and setting of MTA was evaluated. Teeth were restored with stainless steel crowns. Follow-up evaluations were scheduled at 3, 6, 12 months and annually thereafter. Descriptive statistics were used to assess outcomes. Results The age of patients at time of pulpotomy ranged between 7.6 and 13.6 years (mean = 10.7± 1.7 yrs). The majority of teeth (91%) had clinical signs and symptoms consistent with a diagnosis of symptomatic irreversible pulpitis and symptomatic apical periodontitis (78%). The follow-up examination period ranged from 18.9 to 73.6 months. Clinically and radiographically, all pulpotomies were considered successful at the end of the follow-up period. Radiographically, a hard tissue barrier was noticed in 13 (57%) teeth. Conclusion In children, MTA was associated with high clinical and radiographic success as a pulpotomy agent in permanent teeth with clinical signs and symptoms suggestive of irreversible pulpitis.

Growth factor release from dentine matrix by pulp-capping agents promotes pulp tissue repair-associated events.

Abstract: Aim To characterize growth factor release from dentine by pulp-capping agents and to determine the effects of liberated dentine extracellular matrix (dECM) components on pulp cells in the key wound healing processes of migration and cell growth. Methodology Powdered human dentine was exposed to solutions of calcium hydroxide, white and grey mineral trioxide aggregate (MTA) (ProRoot, (Dentsply Tulsa, Tulsa, OK, USA) over 14 days. The solubilized dECM components were dialysed and lyophilized and characterized using multiplex quantitative ELISA. Following dECM component extraction dentine was analysed using Fourier-transformed infrared spectroscopy (FTIR). Primary rat dental pulp cells (RDPCs) were exposed to dECM components (0.1–100 μg mL−1) released by calcium hydroxide, white and grey MTA, and cell growth and chemotactic responses were assessed. Statistical differences between the experimental and control groups were determined using one-way anova. Results A broad range of growth factors, many not previously reported in dentine, were liberated by these pulp-capping agents, including SCF, M-CSF, GM-CSF, IGFBP-1, NGF and GDNF. White and grey MTA liberated more growth factors than calcium hydroxide. FTIR analysis of dentine exposed to pulp-capping agents showed partial depletion of amide bands I, II and III, with little alteration in phosphate peaks compared to untreated dentine. dECM components released by white and grey MTA induced significantly more cell growth at low-to-moderate concentrations (P ≦ 0.05) examined in this study and significantly enhanced cell chemotaxis at all concentrations compared with controls (P ≦ 0.05). Conclusions White and grey MTA solubilize a broad range of bioactive molecules from dentine, which can induce proliferation and chemotaxis in pulp cells.

Biocompatibility of three new calcium silicate-based endodontic sealers on human periodontal ligament stem cells.

Abstract: Aim To evaluate the biocompatibility of three calcium silicate-based endodontic sealers, Bioroot BC Sealer (Septodont, Saint-Maur-des-Fosses, France), Endoseal MTA (EndoSeal, Maruchi, Seoul, Korea) and Nano-ceramic Sealer (B&L Biotech, Fairfax, VA, USA) (NCS), on human periodontal ligament stem cells (hPDLSCs). Methodology Human periodontal ligament stem cells were cultured in the presence of various endodontic sealer eluates for 24 h. Cell viability was determined using the MTT assay. Cell death and changes in phenotype induced by the set endodontic sealer eluates were evaluated through flow cytometry. Also, an in vitro scratch wound-healing model was used to determine their effects in cell migration. Finally, to assess cell morphology and attachment to the different sealers, hPDLSCs were directly seeded onto the material surfaces and analysed by scanning electron microscopy (SEM). One-way analysis of variance (anova) followed by a Bonferroni post-test was performed (P < 0.05). Results At 24 h, cell spreading was evident in the presence of Bioroot BC Sealer (BR) and Nano-ceramic Sealer (NCS), but not Endoseal MTA (ES). At 72 h, BR and NCS exhibited high and moderate cell proliferation, respectively, whereas ES revealed low rates of cell proliferation (P < 0.05). Similar results were obtained in a cell death assay. In addition, hPDLSCs maintained their mesenchymal phenotype in all conditions although their capacity to migrate was higher in the presence of BR. Finally, SEM studies revealed a good degree of proliferation, cell spreading and attachment, especially when using BR and NCS discs. Conclusions BR and NCS were associated with better cytocompatibility than ES. Further in vitro and in vivo investigations are required to confirm the suitability of these calcium silicate-based endodontic sealers for clinical application.

Properties of NeoMTA Plus and MTA Plus cements for endodontics

Abstract: AIM To test a novel calcium silicate cement mixed with a water-based gel (NeoMTA Plus) with regard to chemical-physical properties and apatite-forming ability. METHODOLOGY NeoMTA Plus (Avalon Biomed Inc. Bradenton, FL, USA; lot. 2014090301) and a commercial MTA-based material with similar properties (MTA Plus, Prevest Denpro Limited, Jammu, India; lot. 41001) were tested for ion-releasing ability, initial and final setting times, radiopacity, open and impervious porosity and apparent porosity, water sorption, weight loss, solubility, ability to nucleate calcium phosphates (CaP) after immersion in HBSS (Hank's Balanced Salt Solution) by ESEM-EDX and micro-Raman spectroscopy. The results were analysed statistically with the anova test (P < 0.05). RESULTS NeoMTA Plus had a prolonged setting time (315 min) and a satisfactory radiopacity (3.76 mm Al). Calcium and hydroxyl ion release was significantly greater and more prolonged in comparison with MTA Plus (P < 0.05). Both NeoMTA Plus and MTA Plus had high values of open porosity and solubility. ESEM-EDX and micro-Raman confirmed the ability to nucleate calcium phosphates on their surface after immersion in HBSS. CONCLUSION NeoMTA Plus is a new calcium silicate-based cement for root filling with an adequate radiopacity and prolonged setting time. The ion release and CaP-forming ability could increase stability of the root filling and promote endodontic and periodontal tissue regeneration, enhancing the bioactivity and biocompatibility of the material.

Comparative analysis of the biological effects of the endodontic bioactive cements MTA Angelus, MTA Repair HP and NeoMTA Plus on human dental pulp stem cells

Abstract: Aim To evaluate the biological effects in vitro of MTA Angelus (MTA-Ang; Angelus, Londrina, PR, Brazil), MTA Repair HP (MTA-HP; Angelus,) and NeoMTA Plus (NeoMTA-P; Avalon Biomed Inc, Bradenton, FL, USA) on human dental pulp stem cells (hDPSCs). Methodology Cell viability and cell migration assays were performed using eluates of each material. To evaluate cell morphology and cell attachment to the different materials, hDPSCs were directly seeded onto the material surfaces and analyzed by immunocytofluorescence and scanning electron microscopy, respectively. The chemical composition of the materials was determined by energy dispersive X-ray (EDX) and eluates were analyzed by inductively coupled plasma-mass spectrometry (ICP-MS). Statistical analysis was performed with analysis of variance and Bonferroni or Tukey post-test (α <0.05). Results Undiluted MTA-Ang, MTA-HP and NeoMTA-P displayed a significant increase in cell viability greater than that obtained using complete medium alone (control) (*p<0.05; **p<0.01; ***p<0.001). Moreover, a cell migration assay revealed cell migration rates after incubation with extracts of MTA-Ang, MTA-HP and NeoMTA-P, that were similar to levels obtained in the control group. In addition, stretched cytoskeletal F-actin fibres were detected in the cells treated with the three material extracts. SEM studies revealed a high degree of cell proliferation and attachment on all three materials. EDX analysis demonstrated similar weight percentages of C, O and Ca in all three materials, while other elements such as Al, Si and S were also found. Conclusions MTA-Ang, MTA-HP, and NeoMTA-P were associated with biological effects on hDPSCs in terms of cell proliferation, morphology, migration and attachment. This article is protected by copyright. All rights reserved.

Efficacy of XP-endo finisher files in the removal of calcium hydroxide paste from artificial standardized grooves in the apical third of oval root canals.

Abstract: Aim To compare the efficacy of the XP-endo finisher file (XP) (FKG Dentaire, La Chaux de Fonds, Switzerland) to that of passive ultrasonic irrigation (PUI) and conventional syringe and needle irrigation (SNI) in the removal of calcium hydroxide paste from an artificial standardized groove in the apical third of root canals. Methodology The root canals of 68 mandibular incisors with single oval canals were prepared using Mtwo instruments (VDW GmbH, Munich, Germany) up to size 40, .04 taper. Each tooth was split longitudinally, and in one half of the root, a standardized groove was prepared in the apical part of the specimen. The grooves were filled with Ca(OH)2, and the root halves were reassembled. The roots were randomly divided into two control groups (n = 4) and three experimental groups (n = 20) according to the Ca(OH)2 methods used: XP, PUI and SNI. The amount of remaining medicament was evaluated under X25 magnification using a 4-grade scoring system. Kappa values were calculated for intra- and interobserver agreement evaluation. The differences in the Ca(OH)2 scores amongst the different groups were analysed using the Kruskal–Wallis test. Results None of the tested methods could completely clean the Ca(OH)2 from the artificial standardized groove in the apical third of the root canals. XP and PUI removed significantly more Ca(OH)2 than SNI (P < 0.001), with no significant differences between them (P = 0.238). Conclusions XP and PUI were more effective in removing Ca(OH)2 from artificial standardized grooves in the apical third of root canals than SNI.

Dissolution, dislocation and dimensional changes of endodontic sealers after a solubility challenge: a micro-CT approach.

Abstract: Aim To evaluate, using a novel micro-CT approach, the solubility and dimensional changes of an MTA-based sealer inside the root canal system after a solubility challenge. The MTA-based material (MTA Fillapex) was compared to a gold standard epoxy-based endodontic sealer (AH Plus). Methodology Ten human mandibular premolars with a single canal were divided randomly into two groups (n = 5) according to the sealer used. The canals were instrumented using the Reciproc System (VDW) with a R40 file and filled with R40 gutta-percha cones and one of the sealers. The filled canals were immediately scanned in a micro-CT, and after that, the teeth were immersed in 20 mL phosphate-buffered saline (PBS) at 37 °C for 7 days, when they were removed and rescanned. Final image stacks were registered against the initial stacks and the numerical difference between the initial and final volume of the filling material was obtained. Calculations were performed to identify dimensional changes of the filling material. All image stacks were 3D rendered to disclose areas of dislocation of the filling material inside or outside the root canal. The Shapiro–Wilk's test revealed that data were normally distributed; thus, the Student's t-test was used to detect statistically significant changes, assuming a 5% α-error. Results No significant changes were seen for the percentage volume of material lost after the solubility challenge for both AH Plus and MTA Fillapex groups (1.44% and 1.16%, respectively). A significant difference was, however, found for the volume of filling material which revealed dimensional changes after the solubility test (6.68% for MTA Fillapex and 1.09% for AH Plus). In fact, observation of 3D models disclosed that MTA Fillapex was associated with material extrusion through the foramen in all but one sample. In AH Plus filled samples, no material extrusion was detected. Conclusions Although the solubility of both sealers was similar using this novel micro-CT approach, MTA Fillapex was associated with significant dimensional changes related to material extrusion through the apex after PBS storage compared to AH Plus.

Efficacy of three different pulpotomy agents in primary molars: a randomized control trial

Abstract: Aim To compare the clinical and radiographic efficacy of Biodentine™, ProRoot® White Mineral Trioxide Aggregate (WMTA) and Tempophore™ as pulpotomy medicaments in the treatment of carious primary molars. Methodology A parallel-design, randomized controlled trial was developed. Patients above 3 years of age with carious primary teeth with vital pulps without spontaneous pain or history of swelling were included. Fifty-eight patients (82 teeth) with a mean age of 4.79 ± 1.23 years were included. The teeth were randomized, blinded and allocated to one of the three groups (Biodentine™, ProRoot® WMTA or Tempophore™) for pulpotomy treatment. All teeth were followed up clinically and radiographically (after 6, 12 and 18 months) by two blinded calibrated investigators. A generalized estimating equation (GEE), Wald chi-square test and an intention-to-treat analysis (ITT) with ‘last carried forward’ approach were performed using Statistical Package for Social Sciences v 21.0 (IBM Corp., Armonk, NK, USA). Results Forty-six patients and 69 teeth were available for follow-up after 18 months. Clinical success (radiographic success in parenthesis) was 95.24% (94.4%), 100% (90.9%) and 95.65% (82.4%) in the Biodentine™, ProRoot® WMTA and Tempophore™ groups, respectively, but the difference was not significant. Pulp canal obliteration was significantly different amongst the experimental groups as the Biodentine™ group exhibited significantly more pulp canal obliteration when compared to the ProRoot® WMTA group at 6 months (P = 0.008) and 18 months (P = 0.003). Conclusions After 18-month follow-up, there was no significant difference between Biodentine™ in comparison with ProRoot® WMTA or Tempophore™.

Do smear-layer removal agents affect the push-out bond strength of calcium silicate-based endodontic sealers?

Abstract: Aim To evaluate the effect of 17% ethylenediaminetetraacetic acid (EDTA), 2.25% peracetic acid (PA) or 10% citric acid (CA) on the push-out bond strength of calcium silicate-based endodontic sealers [MTA Fillapex (Angelus, Londrina, Brazil) and Total Fill BC Sealer (FKG, La Chaux-de-Fonds, Switzerland)] to root dentine after different periods of immersion in phosphate-buffered saline (PBS). AH Plus (Dentsply DeTrey, Konstaz, Germany) was used as a reference material for comparison. Methodology Thirty human maxillary incisors were selected and three 1-mm discs were obtained from the middle third of each root. On the axial surface of each disc, three 0.8-mm-diameter holes were drilled through the dentine. After standardized irrigation, each dentine disc from the same root was treated for smear-layer removal with one of the three tested chelating solutions: EDTA, PA or CA. After that, the holes were dried with paper points and filled with one of the three test root canal sealers. The filled dental slices were further immersed in PBS solution (pH 7.2) for 7 days (T1) or 30 days (T2) at 37 °C, before the push-out assay. Friedman, Kruskal–Wallis and Mann–Whitney tests were used respectively to estimate the impact of the independent variables (solutions, sealers and period of PBS immersion) on the push-out bond strength. The level for significance was set at α = 5% and data were further subjected to a Bonferroni correction. Results Solutions and periods of immersion did not significantly influence the displacement resistance (P = 0.285, and P = 0.104, respectively) of sealers to root dentine. On the other hand, the type of sealer significantly affected the push-out bond strength (P = 0.000). AH Plus was associated with greater resistance to dislodgment compared with Total Fill BC Sealer and MTA Fillapex (P = 0.000). MTA Fillapex resulted in the lowest push-out bond strength (P = 0.000). Conclusion The use of different chelating agents did not influence the push-out bond strength of endodontic sealers. Calcium silicate-based sealers had lower push-out bond strength values compared with a conventional epoxy resin-based sealer (AH Plus).

Prevalence of apical periodontitis in root filled teeth: findings from a nationwide survey in Finland

Abstract: AIM To assess the prevalence of apical periodontitis in the Finnish population aged 30 years and older and relate it to the technical quality of root filling by the type of tooth. METHODOLOGY As part of the Finnish nationwide Health 2000 study, panoramic radiographs were used of the dentate subjects (n = 5335) aged 30-95 years (mean 50.2 years) to assess the apical and endodontic status of their teeth (n = 120635). Apical periodontitis (AP) was recorded when the periodontal ligament space was more than double in width, or loss of lamina dura or a periapical radiolucent lesion was seen. Technically, adequate root fillings had a gap of 0-3 mm from the apex; all others were defined as inadequate. Statistical methods included chi-square tests and anova. Risk of AP was estimated as cross-product odds ratio and its 95% confidence interval. RESULTS Teeth with AP occurred in 27% of the dentate subjects being more prevalent in subjects with root filled teeth than in those without (39% vs. 9%; P < 0.001; OR = 6.3; 95% CI 5.3, 7.4). AP was more prevalent in men than in women (31% vs. 23%). At a tooth level, AP was most frequent in mandibular molars with inadequate root fillings. For all root filled teeth, an inadequate root filling doubled the risk of AP for both women (OR = 2.0; 95% CI 1.7, 2.4) and men (OR = 2.5; 95% CI 2.1, 2.9). CONCLUSIONS AP occurred principally in subjects and teeth with root fillings. Inadequate root fillings doubled the risk of AP. An improvement in the technical quality of root canal treatment is essential.

Effect of sonic and ultrasonic activation on organic tissue dissolution from simulated grooves in root canals using sodium hypochlorite and EDTA.

Abstract: Aim To compare soft-tissue dissolution by sodium hypochlorite, with an EDTA intermediate rinse, with or without activation with passive ultrasonic activation (PUI) or sonic activation using the Endoactivator (EA) or Eddy tips (ED). Methodology The root canals of eighty-three human maxillary central incisors were chemo-mechanically prepared and the teeth split. A standardized longitudinal intracanal groove was created in one of the root halves. Eighty-three porcine palatal mucosa samples were collected, adapted to fit into the grooves and weighed. The re-assembled specimens were randomly divided into four experimental groups (n = 20), based on the final rinse: no activation; EA; PUI; ED, using 2.5% sodium hypochlorite, with an EDTA intermediate rinse. A control group (n = 3) was irrigated with distilled water without activation. The solutions were delivered using a syringe and needle 2 mm from working length. Total irrigation time was 150 s, including 60 s of activation in the specific groups. The study was carried out at 36 ± 2 °C. The porcine palatal mucosa samples were weighed after completion of the assays. Student paired t-test and anova were used to assess the intra- and intergroup weight changes. The multiple comparisons were evaluated using Bonferroni correction (α = 0.05). Results Weight loss occurred in all experimental groups. Irrigant activation resulted in greater weight loss when compared to the nonactivated group [vs. EA (P = 0.001); vs. PUI (P < 0.001); vs. ED (P < 0.001)]. No significant differences were found amongst the different activation systems. Conclusions Activation increased the tissue-dissolving activity of irrigants from artificial grooves in root canals of maxillary central incisors.

Micro-CT evaluation of several glide path techniques and ProTaper Next shaping outcomes in maxillary first molar curved canals

Abstract: Aim To evaluate the ability of ProGlider instruments, PathFiles and K-files to maintain canal anatomy during glide path preparation using X-ray computed micro-tomography (micro-CT). Methodology Forty-five extracted maxillary first permanent molars were selected. Mesio-buccal canals were randomly assigned (n = 15) to manual K-file, PathFile or ProGlider groups for glide path preparation. Irrigation was achieved with 5% NaOCl and 10% EDTA. After glide path preparation, each canal was shaped with ProTaper Next X1 and X2 to working length. Specimens were scanned (isotropic voxel size 9.1 μm) for matching volumes and surface areas and post-treatment analyses. Canal volume, surface area, centroid shift, canal geometry variation through ratio of diameter ratios and ratio of cross-sectional areas were assessed in the apical and coronal levels and at the point of maximum canal curvature. One-way factorial anovas were used to evaluate the significance of instrument in the various canal regions. Results Post-glide path analysis revealed that instrument factor was significant at the apical level for both the ratio of diameter ratios and the ratio of cross-sectional areas (P < 0.001), with an improved maintenance of root canal geometry by ProGlider and PathFile. At the coronal level and point of maximum canal curvature, ProGlider demonstrated a tendency to pre-flare the root canal compared with K-file and PathFile. PathFile and ProGlider demonstrated a significantly lower centroid shift compared with K-file at the apical level (P = 0.023). Post-shaping analysis demonstrated a more centred preparation of ProGlider, compared with PathFile and K-files, with no significant differences for other parameters. Conclusions Use of ProGlider instruments led to less canal transportation than PathFiles and K-files.