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The recent discovery of mesenchymal stem cells within periapical lesions (PL-MSC) has presented novel opportunities for managing periradicular diseases in adult teeth by way of enhancing tissue regeneration. This discovery coincides with the current paradigm shift toward biologically driven treatment strategies in endodontics, which have typically been reserved for non-vital immature permanent teeth. One such approach that shows promise is utilizing local endogenous non-collagenous dentine extracellular matrix components (dECM) to recruit and upregulate the intrinsic regenerative capacity of PL-MSCs

Aim To assess the chemical and microstructural characteristics of dentine after the use of two irrigation protocols and correlate this with the antimicrobial properties of HCSC and changes to the dentine structure / chemistry after sealer placement. Methodology Two irrigation protocols - Protocol A using 2% NaOCl used 5mL/5 min and Protocol B with 2% NaOCl (5mL/5 min) followed by 17% EDTA (5mL/3 min) were used to prepare dentine. The chemical and microstructural changes following irrigation were assessed by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and Fourier transform infrared (FT-IR) spectroscopy (n=5) on dentine obtained from the mid-root and coronal parts of extracted human teeth. Four sealers (AH Plus, BioRoot, MTA Fillapex, TotalFill) were characterized by SEM/EDS (n=3). The ability of the sealers to eradicate intratubular Enterococcus faecalis biofilms was assessed by live/dead dye and confocal laser scanning microscopy to measure the percentage of living cells. The effect of combined irrigation and root filling on the dentine was assessed by SEM and EDS analysis (n=5). Statistical analysis was undertaken using one-way ANOVA and a number of post hoc tests to detect intergroup differences. The F test was used for comparison of variances in the microbiology testing. Results The use of NaOCl alone left the smear layer seemingly intact, with traces of chlorine remaining on dentine. The use of BioRoot sealer restored the calcium ion levels of dentine which are depleted by the irrigation with EDTA. BioRoot exhibited antimicrobial properties against intratubular bacteria even in the presence of smear layer (Protocol A). The smear layer removal improved the bactericidal effect of all sealers and Ca2+ leaching. The use of a chelating agent was important for the intratubular sealer penetration for AH Plus but not the other sealers. Conclusion The removal of smear layer was associated with greater penetration of AH Plus into the dentinal tubules but not for the penetration of HCSC sealers. BioRoot was a more effective sealer in reducing the bacterial load in the dentinal tubules than the other materials tested and the presence of smear layer did not affect its activity.

Vital pulp therapies (VPTs) aim to preserve the vitality of the pulp. The European Society of Endodontology have begun a campaign to raise awareness on the efficacy of VPTs following on from the publication of their 2019 position statement, aimed at both specialists and general dental practitioners. This review examines the current evidence surrounding VPTs and provides a rational approach to the management of the exposed pulp with the aid of case studies. Success lies in accurate diagnosis and case selection, along with well-executed treatment and appropriate follow-up protocols. The introduction of calcium silicate cements has made these treatments more predictable.

This is the first article in a series reviewing the current literature surrounding the management of deep caries in permanent teeth. Approaches to caries management are continuing to evolve, with more conservative management increasingly favoured. This philosophy has never been more important than in managing the deep carious lesion. Evidence is emerging that the use of selective caries removal to reduce the risk of pulp exposure, in conjunction with calcium silicate cements, can be successful in maintaining pulp vitality, delaying the restorative cycle and prolonging the lifespan of the tooth.

Aim\ud \ud To establish if irrigant activation techniques, namely manual‐dynamic‐activation (MDA), passive‐ultrasonic‐irrigation (PUI) and sonic‐irrigation (SI), improve the tubular penetration of sodium hypochlorite (NaOCl) into root dentine when compared with conventional‐needle‐irrigation (CNI). Secondly, investigate if increasing NaOCl concentration and/or contact‐time improves the performance of these techniques.\ud Methodology\ud \ud A total of 83 extracted human maxillary permanent canines were decoronated to 15 mm and root canals prepared to a size 40,.10 taper. Root dentine was stained with crystal violet for 72 h and embedded in silicone. Eighty specimens were randomly distributed into 16 groups (n = 5) according to the irrigant activation technique, NaOCl concentration (2%; 5.25%) and irrigant contact‐time (10 min; 20 min). All activation techniques were used for 60 s in the last minute of irrigation. Additionally, 3 teeth were not exposed to NaOCl to confirm adequate dentine staining had occurred (i.e. negative control). All specimens were subsequently dissected, observed under a light microscope and NaOCl penetration depth (µm) determined by measuring the average width of bleached dentine using ImageJ software. Statistical comparisons were made with paired and unpaired t‐tests, ANOVAs followed by post‐hoc Tukey and Dunnett’s tests, and a general linear model (α < 0.05).\ud Results\ud \ud Overall, NaOCl penetration ranged from 38.8 µm – 411.0 µm with MDA, PUI and SI consistently resulting in significantly greater tubular infiltration than CNI (P < 0.05). The deepest measurements in the coronal, middle and apical segments were all recorded in the MDA; 5.25%; 20 min group and the least in the CNI; 2%; 10 min group. Increasing either irrigant concentration or contact‐time resulted in significantly greater NaOCl penetration depths for all techniques and segments of the canal (P < 0.05). However, when irrigant concentration and contact‐time were increased together, a significant interaction effect between these two independent variables was observed on overall NaOCl penetration (P < 0.05).\ud Conclusions\ud \ud Agitating irrigants with MDA, PUI or SI, as well as using greater irrigant concentrations or contact‐times, potentiated NaOCl penetration into root dentine. However, longer durations of NaOCl exposure at lower concentrations resulted in similar depths of tubular penetration as those achieved at higher concentrations.

In teeth with an injured pulp, dentin matrix orchestrates hard tissue repair through the release of dentin extracellular matrix components (dEMCs). dEMCs regulate the differentiation of resident mesenchymal stromal cells (MSCs), thereby affecting mineral deposition. In this study, we show that low-concentration solubilized dEMCs in osteogenic cultures of human umbilical cord mesenchymal stromal cells (UC-MSCs) and dental pulp stromal cells (DPSCs) enhanced mineral deposition, while adipose stromal cells (ASCs) were barely affected. Interestingly, UC-MSCs displayed significantly greater hydroxyapatite formation compared with DPSCs. UC-MSCs and DPSCs showed a dose-dependent viability and proliferation, whereas proliferation of ASCs remained unaffected. Qualitative analysis of the dEMC-supplemented osteogenic cultures through scanning electron microscopy demonstrated differences in the architecture of the deposited mineralized structures. Large-sized mineral accretions on a poorly organized collagen network were the prominent feature of UC-MSC cultures, while mineral nodules interspersed throughout a collagen mesh were observed in the respective DPSC cultures. The ability of dEMCs to induce mineralization varies between different human MSC types in terms of total mineral formation and architecture. Mineral formation by UC-MSCs exposed to low-concentration dEMCs proved to be the most efficient and therefore could be considered a promising combination for mineralized tissue engineering. Impact Statement This research has been conducted with the aim to contribute to the development of treatment modalities for the reconstruction of lost/damaged mineralized tissues. Currently, determining the most appropriate stromal cell population and signaling cues stands at the core of developing effective treatments. We provide new insights into the effect of innate inductive cues found in human dentin matrix components, on the osteogenic differentiation of various human stromal cell types. The effects of dentin extracellular matrix components on umbilical cord mesenchymal stromal cells have not been investigated before. The findings of this study could underpin translational research based on the development of techniques for mineralized tissue engineering and will be of great interest for the readership of Tissue Engineering Part A.

Aim To investigate the consistency of commissioning and provision of enhanced NHS endodontic services across England. Methods The level of provision for enhanced endodontic services was sought using two methods. An electronic questionnaire was distributed to each of the thirteen director of commissioning operations (DCO) teams in NHS England to determine the perception from commissioners of what endodontic services are currently provided and commissioned. A systematic search to assess what is advertised by enhanced endodontic providers was also carried out to cross-reference with the information gained from electronic questionnaires. Results A 77% response rate to the questionnaire was achieved. Eight out of the ten DCO teams that replied provided enhanced NHS endodontics to a greater or lesser extent, one did not and one was unsure. Three teams did not respond. Providers of services included dentists with enhanced skills, endodontic specialists, and dentists working within district or dental hospitals. Five out of ten DCO teams commissioned level two services and six commissioned level three services. Dental hospital acceptance criteria for enhanced endodontics differ regionally, but most accept level three and some level two complexity treatments, depending upon capacity at the time. Conclusions This investigation demonstrates that although the majority of NHS commissioning areas within England provide enhanced endodontic services, these are not the same across the country. Therefore, patients are not getting equal access to services and it may vary depending upon location.

Caries prevalence remains high throughout the world, with the burden of disease increasingly affecting older and socially disadvantaged groups in Western cultures. If left untreated, caries will advance through dentine stimulating pulpitis and eventually pulp infection and necrosis; however, if conservatively managed, pulpal recovery occurs even in deep carious lesions. Traditionally, deep caries management was destructive with nonselective (complete) removal of all carious dentine; however, the promotion of minimally invasive biologically based treatment strategies has been advocated for selective (partial) caries removal and a reduced risk of pulp exposure. Selective caries removal strategies can be one-visit as indirect pulp treatment or two-visit using a stepwise approach. Management strategies for the treatment of the cariously exposed pulp are also shifting with avoidance of pulpectomy and the re-emergence of vital pulp treatment (VPT) techniques such as partial and complete pulpotomy. These changes stem from an improved understanding of the pulp-dentine complex's defensive and reparative response to irritation, with harnessing the release of bioactive dentine matrix components and careful handling of the damaged tissue considered critical. Notably, the development of new pulp capping materials such as mineral trioxide aggregate, which although not an ideal material, has resulted in more predictable treatments from both a histological and a clinical perspective. Unfortunately, the changes in management are only supported by relatively weak evidence with case series, cohort studies and preliminary studies containing low patient numbers forming the bulk of the evidence. As a result, critical questions related to the superiority of one caries removal technique over another, the best pulp capping biomaterial or whether pulp exposure is a negative prognostic factor remain unanswered. There is an urgent need to promote minimally invasive treatment strategies in Operative Dentistry and Endodontology; however, the development of accurate diagnostic tools, evidence-based management strategies and education in management of the exposed pulp are critical in the future.

Surgical extrusion is a recognised treatment option for teeth that have insufficient coronal tooth structure remaining due to deep caries, resorption or traumatic injury. However, the technique has not been widely adopted, arguably because extraction of a severely compromised tooth may be difficult to achieve in a gentle and predictable way. In this paper, we present our novel approach to surgical extrusion and subsequent management of teeth using a vertical extraction system (Benex), which has become the method of choice in the authors' practice for many teeth that would otherwise be deemed unrestorable. We describe the clinical procedure in detail and discuss the advantages and disadvantages compared to alternative approaches, including surgical crown lengthening and orthodontic extrusion.

Introduction Neurotrophic factors play a significant role in the innervation of the pulp-dentin complex during and after organogenesis. There have been numerous bioactive molecules identified in the dentin extracellular matrix; however, the expression of neurotrophic factors in the dentin matrix and their biological activity are largely unknown. The purpose of this study was to characterize the relative expression of neurotrophic factors in human dentin matrix proteins (DMPs) and their effect on neurite outgrowth of trigeminal (TG) neurons. Methods Dentin was powdered in liquid nitrogen from noncarious human third molar teeth. DMPs were solubilized through an EDTA extraction method, dialyzed, and lyophilized until use. The relative expression of nerve growth factor, brain-derived neurotrophic factor, glial cell−line derived neurotrophic factor, neurotrophin 3, and neurotrophin 4/5 was determined by the enzyme-linked immunosorbent assay. Rat TG neurons were cultured and exposed to different concentrations of DMPs (1–105 ng/mL) or vehicle, and a quantitative neurite outgrowth assay was performed. Results Human DMPs contained all of the tested neurotrophic factors, with glial cell−line derived neurotrophic factor and neurotrophin 4/5 found at the highest levels. DMPs were able to promote the neurite outgrowth of rat TG neurons at an optimum concentration of 10–102 ng/mL, whereas the effect was partially inhibited at higher concentrations (>103 ng/mL). Conclusions The human dentin extracellular matrix is a rich reservoir for neurotrophic factors that are key components for neuronal homeostasis, differentiation, and regeneration. These data suggest that neurotrophins in DMPs could play an important role as signaling molecules for the innervation of the pulp-dentin complex during the processes of tooth formation, repair, and regeneration.

Research over several decades has increased our understanding of the nature of reparative and regenerative processes in the dental pulp, at both the cellular and molecular level. However, advances in scientific knowledge have not translated into novel clinical treatment strategies for caries-induced pulpitis. This narrative review explores the evidence regarding the ability of inflamed pulp tissue to heal and how this knowledge may be used therapeutically. A literature search and evidence analysis covering basic, translational and clinical pulp biology research was performed. The review focuses on (1) the regenerative and defense capabilities of the pulp during caries-induced inflammation; (2) the potential of novel biomaterials to harness the reparative and regenerative functions of the inflamed pulp; and (3) future perspectives and opportunities for conservative management of the inflamed pulp. Current conservative management strategies for pulpitis are limited by a combination of unreliable diagnostic tools and an outdated understanding of pulpal pathophysiological responses. This approach leads to the often unnecessary removal of the entire pulp. Consequently, there is a need for better diagnostic approaches and a focus on minimally-invasive treatments utilizing biologically-based regenerative materials and technologies.

In root canal therapy, irrigating solutions are employed to eliminate the bacterial load and also prepare dentin for sealer interaction. The aim of this research was to assess how irrigating solutions employed on their own or in sequence affected the tooth structure. The best way to prepare the tooth for obturation using hydraulic calcium silicate cement (HCSC) sealers and gutta-percha, thus guiding clinicians on a matched irrigation-obturation strategy for optimized root canal treatment was investigated. The effect of irrigating solutions on dentine was investigated by assessing changes in dentin microhardness, ultrastructure and mineral content, organic/inorganic matter, surface roughness and Young’s modulus. The interaction of four root canal sealers with the dentin was analysed by assessing the changes in microhardness of the dentin after sealer placement and also the sealer to dentin interface by scanning electron and confocal laser microscopy. The irrigating solutions damaged the dentin irreversibly both when used on their own and in combination. The best sequence involved sodium hypochlorite followed by chelator and a final rinse with sodium hypochlorite and obturation using HCSC sealers that enabled the restoration of dentin properties. The HCSC sealers did not rely on chelator irrigating solutions for a good material adaptation to dentin.

Aims To investigate current trends in endodontic irrigation amongst general dental practitioners (GDPs) and dental schools within UK and Ireland. Secondly, to evaluate if significant differences exist between the irrigant practices of National Health Service (NHS) and private GDPs.Methodology In 2019, an online questionnaire was distributed to the 18 dental schools within the UK and Ireland and 8,568 GDPs. These surveys explored current trends in teaching and usage of endodontic irrigants. Chi-squared tests were performed to make comparisons between NHS and private GDPs (α0.01).Results All 18 dental schools (100%) and 495 GDPs (6%) returned valid questionnaires. Three hundred and thirty (66.7%) practitioners were NHS and 165 (33.3%) were private. There was strong consensus on irrigation teaching amongst dental schools. These results aligned with GDP responses in terms of irrigant selection (sodium hypochlorite [NaOCl]); NaOCl concentration (≤3%); ethylenediaminetetraacetic acid (EDTA) contact time (0-5 minutes); final rinse protocols (penultimate EDTA rinse); irrigant temperature (room); and agitation techniques (manual dynamic activation;0-60 seconds). There was, however, considerable variation in NaOCl contact time and GDPs infrequently used chelating agents or agitation techniques. Compared with private practitioners, NHS GDPs used significantly lower NaOCl contact times and concentrations, less EDTA and activation techniques, and more chlorhexidine (P0.01).Conclusions Overall, irrigation teaching within the UK and Ireland is consistent and evidence-based. Furthermore, trends in irrigant usage amongst UK GDPs are now more aligned with these teaching practices. Significant differences were, however, observed between NHS and private practitioners.

Made available in DSpace on 2020-12-12T02:29:45Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-06-01 Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Background/Aim: In addition to their anti-inflammatory and anti-osteoclastogenesis properties, adrenergic blockers may also have promising anti-resorptive effects that can prevent root resorption when teeth are replanted because of avulsion. The aim of this study was to investigate the effects of phentolamine (Ph) and propranolol (Pr) in gels on the repair process of late replanted rat incisors. A further aim was to evaluate the biocompatibility of both drugs to human periodontal ligament fibroblasts (HPDLFs). Materials and methods: Forty-eight maxillary right incisors were extracted from male Wistar rats, stored in paper napkins for 60 minutes, and randomly allocated to one of eight groups (n = 6). The root canal, root surface, and alveolus were treated with 0.75 µg/mL Ph gel (Ph0.75), 10 µg/mL Ph gel (Ph10), 100 µg/mL Ph gel (Ph100), 2.5 µg/mL Pr gel (Pr2.5), 10 µg/mL Pr gel (Pr10), 100 µg/mL Pr gel (Pr100), or sodium carboxymethylcellulose gel (CMC) before replantation. In the control group (CH), only the root canal was treated with calcium hydroxide paste. Thirty days following surgery, the animals were euthanized, and the right hemimaxilla was removed to perform micro-CT and histomorphometric analysis to determine osteoclastic activity. Ethanolic solutions of Ph10 and Pr10 were selected based on the in vivo study, and the viability of HPDLFs stimulated with lipopolysaccharide was determined by MTT assays. Results: The micro-CT and histomorphometric analysis revealed no significant differences among the treatments (P >.05). The presence of active osteoclasts was significantly decreased in the Ph10 and Pr10 groups (P .05). Conclusions: Ph10 and Pr10 significantly decreased osteoclastogenesis in delayed replanted rat teeth and were not cytotoxic toward HPDLFs. Department of Restorative Dentistry Endodontic Division Institute of Science and Technology São Paulo State University (Unesp) Department of Biosciences and Oral Diagnosis Institute of Science and Technology São Paulo State University (Unesp) Department of Oral Biology Institute of Clinical Sciences The University of Birmingham School of Dentistry Department of Restorative Dentistry Endodontic Division Institute of Science and Technology São Paulo State University (Unesp) Department of Biosciences and Oral Diagnosis Institute of Science and Technology São Paulo State University (Unesp) CNPq: 431807/2016-7

AIM To compare the educational benefits and user friendliness of two anonymized endodontic case difficulty assessment (CDA) methods. METHODOLOGY A cohort (n = 206) of fourth-year undergraduate dental students were recruited from four different Dental Schools and divided randomly into two groups (Group A and B). The participants assessed six test endodontic cases using anonymized versions of the American Association of Endodontists (AAE) case difficulty assessment form (AAE Endodontic Case Difficulty Assessment Form and Guidelines, 2006) and EndoApp, a web-based CDA tool. Group A (n = 107) used the AAE form for assessment of the first three cases, followed by EndoApp for the latter. Group B (n = 99) used EndoApp for the initial three cases and switched to the AAE form for the remainder. Data were collected online and analysed to assess participants' knowledge reinforcement and agreement with the recommendation generated. Statistical analysis was performed using the two-way mixed model anova, Cohen's Kappa (κ) and independent t-tests, with the levels of significance set at P

Interactive intelligent services, such as smart web search, are important datacenter workloads. They rely on dataintensive deep learning (DL) algorithms with strict latency constraints and thus require balancing both data movement and compute capabilities. As such, a persistent approach that keeps the entire DL model on-chip is becoming the new norm for realtime services to avoid the expensive off-chip memory accesses. This approach is adopted in Microsoft's Brainwave and is also provided by Nvidia's cuDNN libraries. This paper presents a comparative study of FPGA, GPU, and FPGA+ASIC in-package solutions for persistent DL. Unlike prior work, we offer a fair and direct comparison targeting common numerical precisions (FP32, INT8) and modern high-end FPGA (Intel® Stratix®10), GPU (Nvidia Volta), and ASIC (10 nm process), all using the persistent approach. We show that Stratix 10 FPGAs offer 2.7× (FP32) to 8.6× (INT8) lower latency than Volta GPUs across RNN, GRU, and LSTM workloads from DeepBench. The GPU can only utilize ~6% of its peak TOPS, while the FPGA with a more balanced on-chip memory and compute can achieve much higher utilization (~57%). We also study integrating an ASIC chiplet, TensorRAM, with an FPGA as system-in-package to enhance on-chip memory capacity and bandwidth, and provide compute throughput matching the required bandwidth. We show that a small 32 mm2 TensorRAM 10nm chiplet can offer 64 MB memory, 32 TB/s on-chiplet bandwidth, and 64 TOPS (INT8). A small Stratix 10 FPGA with a TensorRAM (INT8) offers 15.9× better latency than GPU (FP32) and 34× higher energy efficiency. It has 2× aggregate on-chip memory capacity compared to a large FPGA or GPU. Overall, our study shows that the FPGA is better than the GPU for persistent DL, and when integrated with an ASIC chiplet, it can offer a more compelling solution.

This clinical report describes the use of an "atraumatic" vertical extraction system to facilitate the restorative treatment of a tooth that would otherwise be considered unrestorable because of subgingival caries. Minimally invasive surgical root extrusion was undertaken using the Benex extraction system, which can provide controlled tooth extrusion with minimal deformation of the bone socket. A carious endodontically treated mandibular premolar was extruded to provide routine restorative treatment and endodontic retreatment.

Prevention or treatment of apical periodontitis is aimed at disinfecting the root canal system so that the periradicular tissues are not vulnerable to attack from microbiota within the tooth. This is achieved by a process of cleaning and shaping the root canal space. The fundamental principles underlying this process have not changed in decades. In contrast, the armamentarium available to the clinician continues to evolve rapidly. The use of specially designed nickel titanium (NiTi) files to create a glidepath allows the clinician to manage tight curved canals more predictably in situations which would otherwise have proved too difficult using conventional techniques. Other files, designed to shape the canal, have been developed using metallurgic principles which permit NiTi files to be more flexible and resistant to cyclic fatigue. These newer systems also require fewer instruments to prepare a canal and some, which have adopted a reciprocating (rotational) motion, may only require one file. Progress is also being made in enhancing efficacy of irrigant activity using negative apical pressure systems, sonic and ultrasonic agitation techniques. These contemporary techniques used to clean and shape the root canal system should result in improved confidence and predictability when managing endodontic disease.

AIM To investigate how preparation of a simulated access cavity into ceramic materials suitable for the manufacture of dentine-bonded crowns (DBCs) impacted on biaxial flexural strength (BFS) determined as a monolithic structure and in a more clinically representative resin-cemented form. METHODOLOGY One hundred and twenty feldspathic and 120 leucite-reinforced ceramic disc-shaped specimens were divided into eight groups (n = 30). All groups received 'fit' surface treatments representative of pre-cementation modifications and of cementation prior to preparation of a representative endodontic access cavity through the sample. BFS was determined for both 'intact' and the 'annular' disc-shaped specimens which had received simulated endodontic access. Newly reported analytical solutions were used to calculate BFS of the 'annular' specimens. Statistical analysis included two-way anovas (α = 0.05) and Weibull analysis. Fractographic examination provided insight into the fracture mechanisms. RESULTS A two-way anova identified a significant impact of material (P

Aim The primary aim was to identify techniques used to sample and analyse periradicular tissue fluid (PTF) in permanent teeth diagnosed with apical disease during root canal treatment. Secondly, to identify the types of inflammatory mediators studied using this approach. Methodology Data Sources: PubMed, EMBASE, Cochrane Library, Science Direct, Web of Science and OpenGrey. Eligibility Criteria: Clinical studies published until 1 June 2018 which utilized orthograde techniques to sample and analyse PTF were included. Cell culture, laboratory or animal studies and those concerned with investigating inflammatory mediator activity from within healthy or diseased pulp tissue, and not periradicular tissues, were excluded. Study appraisal and methods: In accordance with PRISMA guidelines, data were extracted on study characteristics, target mediators, sampling and assay techniques and the parameters associated with the PTF sampling and eluting protocol. A qualitative synthesis was conducted, and studies were critically appraised using a modified version of the Cochrane risk of bias tool. Results Study Characteristics: From 251 studies, 33 were eligible for inclusion. Sampling techniques included the use of paper points (n = 27), fine needle aspiration (n = 4) and filter strips (n = 2). Assay techniques included enzyme-linked immunosorbent assay (n = 18), quantitative polymerase chain reaction (n = 9), radioimmunoassay (n = 4), colorimetric assay (n = 2), immunofluorometric assay (n = 1) and cytometric bead array (n = 1). Forty-five different inflammatory mediators were targeted at the proteomic/metabolomic (n = 25) or transcriptomic level (n = 9). Limitations Significant heterogeneity exists within the methodology, and only 5 studies disclosed unambiguous information about their PTF sampling and eluting protocols. Conclusions Paper points and proteomic/metabolomic analysis are currently the preferred methods for studying and analysing PTF during root canal treatment. The most studied analytes were IL-1β and TNF-α. Implications Further research is required to develop an optimized PTF sampling and eluting protocol to overcome methodological heterogeneity, and future studies are advised to follow a standardized approach to reporting their methodology.

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As substitutes to endodontic treatments, since many years biodentistry implicates pulp capping with Ca(OH)2 and/or some molecules of the extracellular matrix (ECM). Pulp cells are committed. They proliferate and differentiate, two successive processes leading to the repair and regeneration of a pulp exposure. Specifically, reactionary and reparative dentins lead to the formation and thickening of dentinal bridges, enhancing the residual dentin thickness to the detriment of the pulp volume. In case of more severe decay of the pulp, repair and regeneration result from the formation of a dense ECM, which will further underwent mineralization after the reduction of the inflammatory process, revascularization, and nerve sprouting. In some conditions, in the coronal part or in the apical part of the pulp, endogenous cells that are still present may proliferate and reconstitute a fibrous but sound conventional tissue. In case of severe infection, the removal of the wounded tissue may be followed by the implantation of a scaffold within the root and/or pulp chamber. Combined with pulp stem cells or not, these approaches may contribute (1) to endodontic soft tissue regeneration and (2) followed by an artificial pulp mineralization, filling all the empty pulp spaces. These biological approaches may pave the way for the future for endodontic treatments.

Each stage of root canal treatment should be carried out to the highest possible standard. The access cavity is arguably the most important technical stage, as subsequent preparation of the root canal(s) can be severely comprised if this is not well executed. Inadequate access can lead to canals being left untreated, poorly disinfected, difficult to shape and obturate, and may ultimately lead to the failure of the treatment. This paper highlights common features in root canal anatomy and outlines basic principles for locating root canals and producing a good access cavity. It also explores each phase of the preparation in detail and offers suggestions of instruments that have been specifically designed to overcome potential difficulties in the process. Good access design and preparation will result in an operative environment which will facilitate cleaning, shaping and obturation of the root canal system in order to maximise success.

OBJECTIVES: Management of carious teeth with signs and symptoms indicative of irreversible pulpitis is traditionally invasive, but emerging evidence suggests successful treatment outcomes with less invasive vital pulp treatment such as coronal pulpotomy. The objective of this systematic review is to determine whether coronal pulpotomy is clinically effective in treating carious teeth with signs and symptoms indicative of irreversible pulpitis.SOURCES: MEDLINE; PubMed; Embase, Web of Science, Cochrane Central Register of Controlled Trials, International Clinical Trials Registry Platform and ClinicalTrials.gov were searched until December 2018.STUDY SELECTION: Prospective, retrospective and randomised clinical trials investigating coronal pulpotomy or comparing pulpotomy to root canal treatment in permanent mature carious teeth with signs and symptoms indicative of irreversible pulpitis were included. Studies were independently assessed for risk of bias using Cochrane Systematic Reviews of intervention criteria and modified Downs and Black quality assessment checklist.DATA: Eight articles were selected for analysis. The average success rate for coronal pulpotomy was 97.4% clinical and 95.4% radiographic at 12 month follow-up. This was reduced to 93.97% clinical and 88.39% radiographic success at 36 months follow-up. Results from the only comparative clinical trial showed pulpotomy to have comparable success to root canal treatment at 12, 24 and 60 month follow-up.CONCLUSIONS: The evidence suggests high success for pulpotomy for teeth with signs and symptoms of irreversible pulpitis, however, results are based on heterogeneous studies with high risk of bias. Well-designed, adequately powered randomised controlled trials are required for evidence to change clinical practice.CLINICAL SIGNIFICANCE: Management of carious teeth with irreversible pulpitis is traditionally invasive, but emerging evidence suggests potentially successful treatment outcomes with less invasive therapies such as coronal pulpotomy.

Crown down preparation is the most known and described technique since the introduction of Nickel Titanium (NiTi) rotary instruments in endodontics. This technique gives good results but has limitations, such as not addressing the initial anatomy of oval or dumb-bell shaped canals. The specific design of the Protaper instruments allows use of them with a different technique and, specifically, with a brushing motion in the body of the canal. The recent introduction of hand Protaper files has expanded the range of application of this system, especially in curved canals. The 'hybrid technique', using rotary and hand files, and the advantages of the combination of both instruments, are clearly described in this article. Used with this technique, the Protaper is a very safe system to use, and more controllable, for both inexperienced and experienced practitioners alike, than other systems.To understand the precautions needed with rotary files, and how to use them to preserve the anatomy of the canal and get a tapered shaping, even in severely curved canals.

Posterior composite resin restorations are an established feature of contemporary dental practice and all new dental graduates should be competent in providing such treatments for their patients. Surveys of educational curricula in this area in the United Kingdom and Ireland, as well as North America, have demonstrated variations both within and between dental schools. Such inconsistency does not help new dental school graduates, and may lead to confusion. At the British Association of Teachers of Conservative Dentistry Annual Conference held in Birmingham in September 2005, a session was devoted to the development of guidelines for dental schools on teaching posterior composite resin restorations to dental undergraduates. The theme of the conference concerned the teaching implications for changing from amalgam to composite. Two of the principal speakers at the meeting (Joost Roeters and Niek Opdam) were from the dental school at the University of Nijmegen in the Netherlands. This school was the first in Europe to discontinue the use of dental amalgam in its undergraduate curriculum over a decade ago. This paper reports the consensus views of those present on guidelines for teaching posterior composite resin restorations to dental undergraduate students.

The aim of this study was to evaluate variations in power output of different Piezon-Master 400 (Electro Medical Systems, Nyon, Switzerland) ultrasonically driven generators and analytic handpieces at a range of power settings. A scanning laser vibrometer was used to measure the maximum vibration displacement amplitude of a KiS 2D tip. Ten repeat scans were made of the unloaded tip oscillation at six power settings. Data were acquired from four different generators and handpieces. Linear trend lines fitted to all tip data showed that none of the generator/handpiece combinations produced a linear increase in tip displacement amplitude with increasing power setting. A univariate analysis of variance (general linear model) showed that generator, handpiece, and power were all significant variables (p

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.

Root canal therapy is not always successful and an increasing number of patients are requesting retreatment to address intra-radicular infection. The armamentarium available to assist the dentist, some of which is described in this article, has never been greater.This paper discusses the causes of failure and reviews many of the techniques available to the practitioner to tackle the problem.

Modern post preparation techniques reflect a change from what was once considered a prosthodontic procedure to one which marries endodontic principles with sound understanding of mechanical objectives. This article presents a rationale for techniques in materials selection and post-space preparation. A review of literature is presented and practical clinical guidelines are suggested when post placement is considered the treatment of choice.

Indirect restorations can provide a conservative, functional and aesthetic method for managing a patient's dentition. These restorations, however, are only as good as the environment in which they are placed. Many restorations, though technically satisfactory, may fail because assessment and subsequent treatment planning has been unsatisfactory. This article presents a philosophy of case selection mindful of factors related to the patient, operator and oral environment. The wrong treatment, however skilfully executed, may invite failure.

This article will provide an overview of the rationale behind taking a contemporary approach to obturation of the root canal system. It will outline a broad range of obturation materials including those traditionally used and newer, advanced ones that are now available that have active physical and biological properties. Obturation techniques will be described in detail, including advice for those difficult cases such as managing obturation of a canal with a wide open apex. Assessment of obturation will also be discussed, considering those factors which affect outcome of root canal treatment.

Extracellular matrix of dentine contains a rich cocktail of soluble cytokines and growth factors which mediate wound repair of the dentine-pulp complex. Hepatocyte growth factor (HGF) is a mesenchyme derived growth factor regulating a broad range of physiological processes including tissue development and regeneration. In this study, we have investigated the sequestration of HGF in the dentine matrix and analysed its action as a chemokine in the induction of differentiation and mineral deposition in pulp derived cells in vitro. Using ELISA, the presence of HGF was demonstrated in solubilised fractions of dentine matrix released by the therapeutic pulp repair materials of white and grey mineral trioxide aggregate. HGF was shown to be a chemo-attractant for primary rat dental pulp cells (RDPCs) in transwell assays highlighting its potential in progenitor cell recruitment during dentine-pulp tissue repair. Transcription factors Osterix and Runx2, and genes encoding for Osteopontin and Osteocalcin, were up-regulated in HGF-exposed RDPC cultures compared with controls. Adenoviral-mediated expression of HGF in RDPCs or exposure to recombinant HGF induced mineral secretion in RDPCs which was significantly greater than controls. The receptor of HGF, c-Met was also detected within human dental pulp indicating the potential for HGF released from dentine matrix to contribute to cellular signalling events following tissue injury. Combined, these data suggest that HGF is important in the repair of the dentine-pulp complex potentially participating in several aspects of wound healing.

Dentistry is entering an exciting era in which many of the advances in biotechnology offer opportunities for exploitation in novel and more effective therapies. Pulp healing is complex and dependent on the extent of injury, among many other factors. Many of the molecular and cellular processes involved in these healing events recapitulate developmental processes. The regulation of odontoblast activity is clearly central to pulp healing, and an understanding of the mechanisms involved in these processes is necessary to enable laboratory studies to be translated to clinic application. Transcriptome analysis has identified changes in many odontoblast genes during the life-cycle of this cell and its responses to injurious challenge. The p38 MAPKinase pathway appears to be central to the transcriptional control of odontoblasts and may provide a key target for therapeutic intervention. The many recent advances in knowledge of pulpal stem cells and molecular signaling molecules within the tooth, now provide exciting opportunities for clinical translation to novel therapies. Such translation will require the partnership of researchers and skilled clinicians who can effectively apply advances in knowledge to appropriate clinical cases and develop novel therapies which can be realistically introduced into the clinic.

The fracture of an instrument is a recognized complication in endodontics. The immediate response to a fractured instrument is frequently to regard the treatment as a failure. Several factors must, however, be taken into account to evaluate the prognosis of the tooth in this situation. The objective of the endodontic treatment with or without a fractured instrument remains the same, namely to disinfect the root canal system and prevent its recontamination. The time at which file fracture occurred during treatment and the degree of canal infection should be considered when determining the potential effect of instrument fracture on treatment outcome. Patients must be informed about an instrument fracturing in their tooth for ethical and legal reasons. The aim of this paper is to attempt to place fractured instruments in context, not to provide an in depth description of fractured instrument management techniques.To understand the influence of fractured instruments on prognosis in endodontics.

Considerable focus on the biocompatibility of dental materials over the last three decades has provided a platform for a wealth of studies on the cellular and molecular responses of the cells of the pulp to injury, both from the disease process and from subsequent restorative intervention. These studies have been fundamental to understanding not only how we can achieve a biocompatible response during restoration of dental disease but also how we can exploit the pulpal cellular responses to achieve wound healing and tissue regeneration in the dentine-pulp complex. This article examines the responses of the pulp to injury and the events leading to tissue regeneration. As new biologically based regenerative therapies emerge for the dental tissues, it is important that these develop in partnership with more traditional approaches using dental materials.

This clinical report presents a patient who developed peri-implant bone loss around 2 maxillary endosseous root-form implants after restoration with cement-retained single crowns. Significant localized bone loss occurred around 1 of the implants due to retained excess cement. Reparative treatment consisted of a guided bone regeneration technique. Following a 9-month period of submerged healing, the implants were re-exposed and restored to complete function.

Aim To correlate the vibrations of a retro tip under a range of loads and generator powers with its cutting ability. Methodology A scanning laser vibrometer was used to measure the maximum vibration displacement amplitude of a KiS 2D tip (Obtura Spartan, USA) under loads of 10–50 g (10 g increments). Loads were applied by contacting the tip against a polished root dentine surface (1200 grit) and were measured using a load cell (RDP Electronics, UK). A calibrated scale was placed over the power dial of the generator (Piezon Master 400; EMS, Switzerland) which enabled incremental power settings (1–5) to be selected between minimum and quarter power of the total generator output. Ten repeat scans were made for each load and generator power combination. The retro tip was then used to create cavities in polished dentine surfaces. The tip was operated using the same experimental conditions as described above (five power settings, 10–50 g loads). For each condition, the tip was contacted against surfaces for 5 s and used to make 10 repeat cavities. Cavities were scanned with a 3D laser profilometer (TaiCaan, UK), enabling the maximum width and length of the cavity to be measured. The same generator and handpiece were used throughout the experiment. Results Load significantly reduced tip vibration displacement amplitude at 30–50 g (P

Aim To evaluate the variability in power output between Piezon-Master 400 generators (EMS) with different Analytic handpieces (Analytic). The displacement amplitude of an unloaded KiS 2D (Obtura Spartan) root end preparation tip was measured using a Scanning Laser Vibrometer (SLV; Polytec) over a range of generator power settings. Methodology Four Piezon-Master 400 ultrasound generators were each used in conjunction with four analytic handpieces. A graduated scale was positioned over the power dial of each of the ultrasound generators to enable incremental power settings to be selected (six settings were used between the minimum and the 9 o'clock position). The handpiece with a KiS 2D tip was fixed in position so that the anterior surface of the tip was vertical and perpendicular to the scanner head of an SLV. Previous investigation showed that the maximum displacement amplitude of the oscillating tip occurred at the unconstrained end. The laser from the SLV was therefore scanned over this point to assess the maximum displacement amplitude. Scans were repeated 10 times for each power setting. The whole process was then repeated for all generator/handpiece combinations. Throughout the investigation, irrigation was used at a constant flow rate of 20 mL min−1. Results Linear trend lines fitted to all tip data showed that none of the generator/handpiece combinations produced a linear increase in tip displacement amplitude with increasing power setting. A univariate analysis of variance (general linear model) showed that generator, handpiece and power were all significant variables (P 0.66). No significant differences were found between handpieces 1 and 4 (P > 0.98) and handpieces 2 and 3 (P > 0.82). All other handpieces were significantly different from each other (P