Periradicular tissue fluid-derived biomarkers for apical periodontitis: An in vitro methodological and in vivo cross-sectional study.

BACKGROUND: Periradicular tissue fluid (PTF) offers a source of diagnostic, prognostic and predictive biomarkers for endodontic disease. AIMS: (1) To optimize basic parameters for PTF paper point sampling in vitro for subsequent in vivo application. (2) To compare proteomes of PTF from teeth with normal apical tissues (NAT) and asymptomatic apical periodontitis (AAP) using high-throughput panels. METHODOLOGY: (1) To assess volume absorbance, paper points (n = 20) of multiple brands, sizes and sampling durations were inserted into PBS/1%BSA at several depths. Wetted lengths (mm) were measured against standard curves to determine volume absorbance (µL). To assess analyte recovery, paper points (n = 6) loaded with 2 µL recombinant IL-1ß (15.6 ng/mL) were eluted into 250 µL: (i) PBS; (ii) PBS/1% BSA; (iii) PBS/0.1% Tween20; (iv) PBS/0.25 M NaCl. These then underwent: (i) vortexing; (ii) vortexing/centrifugation; (iii) centrifugation; (iv) incubation/vortexing/centrifugation. Sandwich-ELISAs determined analyte recovery (%) against positive controls. (2) Using optimized protocols, PTF was retrieved from permanent teeth with NAT or AAP after accessing root canals. Samples, normalized to total fluid volume (TFV), were analysed to determine proteomic profiles (pg/TFV) of NAT and AAP via O-link Target-48 panel. Correlations between AAP and diagnostic accuracy were explored using principal-component analysis (PCA) and area under receive-operating-characteristic curves (AUC [95% CI]), respectively. Statistical comparisons were made using Mann-Whitney U, anova and post hoc Bonferonni tests (α < .01). RESULTS: (1) UnoDent's 'Classic' points facilitated maximum volume absorbance (p < .05), with no significant differences after 60 s (1.6 µL [1.30-1.73]), 1 mm depth and up to 40/0.02 (2.2 µL [1.98-2.20]). For elution, vortexing (89.3%) and PBS/1% BSA (86.9%) yielded the largest IL-1ß recovery (p < .05). (2) 41 (NAT: 13; AAP: 31) PTF samples proceeded to analysis. The panel detected 18 analytes (CCL-2, -3, -4; CSF-1; CXCL-8, -9; HGF; IL-1ß, -6, -17A, -18; MMP-1, -12; OLR-1; OSM; TNFSF-10, -12; VEGF-A) in ≥75% of AAP samples at statistically higher concentrations (p < .01). CXCL-8, IL-1ß, OLR-1, OSM and TNFSF-12 were strongly correlated to AAP. 'Excellent' diagnostic performance was observed for TNFSF-12 (AUC: 0.94 [95% CI: 0.86-1.00]) and the PCA-derived cluster (AUC: 0.96 [95% CI: 0.89-1.00]). CONCLUSIONS: Optimized PTF sampling parameters were identified in this study. When applied clinically, high-throughput proteomic analyses revealed complex interconnected networks of potential biomarkers. TNFSF-12 discriminated periradicular disease from health the greatest; however, clustering analytes further improved diagnostic accuracy. Additional independent investigations are required to validate these findings.

Effectiveness of pulpotomy compared with root canal treatment in managing non-traumatic pulpitis associated with spontaneous pain: A systematic review and meta-analysis.

BACKGROUND: Pulpitis characterized by spontaneous pain can result in debilitating pain. Dogma has existed to offer only have two treatment options, namely root canal treatment (RCT) or extraction, although pulpotomy has always remained a potential treatment modality. OBJECTIVE: This review aimed to answer the following research question: 'Does pulpotomy (partial or full) (I) result in better patient and clinical reported outcomes (O), compared with RCT (C) in permanent teeth with pulpitis characterized by spontaneous pain (P) evaluated at various time intervals?' (T). METHODS: Two authors independently performed study selection, data extraction and risk of bias assessment. The literature search was conducted in the following electronic databases: Clarivate Analytics' Web of Science, Scopus, PubMed and Cochrane Central Register of Controlled Trials. English language clinical trials comparing the patient and clinical reported outcomes between RCT and pulpotomy were included. The meta-analysis was performed on a fixed-effect model and the quality of evidence assessed by the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) approach. RESULTS: Two randomized clinical trials were included. Amongst two trials, one has published four reports at different time points involving the same cohorts. The meta-analysis revealed no difference in postoperative pain (Day 7) between RCT and pulpotomy (OR = 0.99, 95% CI 0.63-1.55, I2  = 0%) and quality of evidence was graded as 'High'. Clinical success was high at year 1, 98% for both interventions, however, decreased over time to 78.1% (pulpotomy) and 75.3% (RCT) at 5 years. DISCUSSION: Pulpotomy is a definitive treatment modality that is as effective as RCT. This could have a significant impact on treatment of such patients affording the advantages of retaining a vital pulp and preventing the need for RCT. CONCLUSION: This review could only include two trials, hence there is insufficient evidence to draw robust conclusions. The clinical data accumulated so far suggests no difference in pain between RCT and pulpotomy at Day 7 postoperatively and a single randomized control trial suggests that the clinical success rate for both treatment modalities is similar long term. There is a need for more well-designed trials by different research groups to develop a stronger evidence base in this area. REGISTRATION: PROSPERO database (CRD42021259744).

Exploiting Dentine Matrix Proteins in Cell-Free Approaches for Periradicular Tissue Engineering.

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 in situ. At picogram levels, these morphogens have demonstrated tremendous ability to enhance the cellular activities in in vitro and in vivo animal studies that would otherwise be necessary for periradicular regeneration. Briefly, these include proliferation, viability, migration, differentiation, and mineralization. Therefore, topical application of dECMs during ortho- or retrograde root canal treatment could potentially enhance and sustain the regenerative mechanisms within diseased periapical tissues that are responsible for attaining favorable clinical and radiographic outcomes. This would provide many advantages when compared with conventional antimicrobial-only therapies for apical periodontitis (AP), which do not directly stimulate healing and have had stagnant success rates over the past five decades despite significant advances in operative techniques. The aim of this narrative review was to present the novel concept of exploiting endogenous dECMs as clinical tools for treating AP in mature permanent teeth. A large scope of literature was summarized to discuss the issues associated with conventional treatment modalities; current knowledge surrounding PL-MSCs; composition of the dECM; inductive potentials of dECM morphogens in other odontogenic stem cell niches; how treatment protocols can be adapted to take advantage of dECMs and PL-MSCs; and finally, the challenges currently impeding successful clinical translation alongside directions for future research. Impact statement Apical periodontitis (AP) is an inflammatory condition that is associated with a great degree of morbidity and ultimately leads to tooth loss. The purpose of this review was to summarize the current evidence pertaining to stem cell therapy in endodontics and present a novel clinical methodology through which they may be utilized to address AP. A comprehensive overview of the basic science, clinical translation, and potential challenges are presented in this review.

The single cone obturation technique with a modified warm filler.

OBJECTIVES: The aim of this study was to develop a new method of obturation by warm sealer in conjunction to single cone gutta-percha and evaluate the suitability of this technique to obturate complex root canal systems. METHODOLOGY: Three root canal sealers namely, AH Plus, BioRoot RCS, GuttaFlow and a prototype sealer composed of tricalcium silicate and 30% zirconium oxide mixed with water and water-soluble polymer were investigated. The sealers were tested for flow, film thickness, setting time and radiopacity following ISO 6876 (2012) recommendations at room temperature and following heat application at 100°C to change the sealer properties. All the test sealers were characterized by scanning electron microscopy and energy dispersive spectroscopy. The volume of voids when used with a single cone obturation technique both unmodified and modified by heat was evaluated using microcomputed tomography. RESULTS: Although the prototype sealer was designed to be similar to the BioRoot, its physical properties were found to be different. All sealers tested were affected by the heat and exhibited a change in the physical properties mainly the setting time, flow, film thickness and void volume. CONCLUSIONS: The application of heat affected the sealer properties and void volume. The single cone obturation technique may not be suitable for complex canal anatomy and furthermore, AH Plus should not be subjected to high temperatures as its properties deteriorate and void volume increases.

Pulpotomy for mature carious teeth with symptoms of irreversible pulpitis: A systematic review.

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.

Enhanced NHS endodontic services in England: a postcode lottery?

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.

Restoring the unrestorable! Developing coronal tooth tissue with a minimally invasive surgical extrusion technique.

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.

Expression of Neurotrophic Factors in Human Dentin and Their Regulation of Trigeminal Neurite Outgrowth.

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.

Effect of Dentin Matrix Components on the Mineralization of Human Mesenchymal Stromal Cells.

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.

Atraumatic surgical extrusion to improve tooth restorability: A clinical report.

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.

Contemporary Cleaning and Shaping of the Root Canal System.

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.

Regenerative endodontics: regeneration or repair?

Recent advances in biotechnology and translational research have made it possible to provide treatment modalities that protect the vital pulp, allow manipulation of reactionary and reparative dentinogenesis, and, more recently, permit revascularization of an infected root canal space. These approaches are referred to as regenerative procedures. The method currently used to determine the origin of the tissue secreted during the repair/regeneration process is largely based on the identification of cellular markers (usually proteins) left by cells that were responsible for this tissue production. The presence of these proteins in conjunction with other indicators of cellular behavior (especially biomineralization) and analysis of the structure of the newly generated tissue allow conclusions to be made of how it was formed. Thus far, it has not been possible to truly establish the biological mechanism controlling tertiary dentinogenesis. This article considers current therapeutic techniques to treat the dentin-pulp complex and contextualize them in terms of reparative and regenerative processes. Although it may be considered a semantic argument rather than a biological one, the definitions of regeneration and repair are explored to clarify our position in this era of regenerative endodontics.

Hepatocyte growth factor is sequestered in dentine matrix and promotes regeneration-associated events in dental pulp cells.

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.

Dissolution of bio-active dentine matrix components by mineral trioxide aggregate.

OBJECTIVES: To analyze the soluble components of setting and set mineral trioxide aggregate (MTA), assess the abilities of two varieties of MTA and Ca(OH)(2) solutions to solubilise dentine matrix proteins (DMPs) and determine if these extracts contain signalling molecules important to pulpal repair and regeneration. METHODS: The metallic ion composition of solutions of white and grey MTA (pH 11.7), 0.02M Ca(OH)(2) (pH 11.9) and 10% EDTA (pH 7.2) was determined using atomic absorption spectroscopy. Extracellular dentine matrix components from powdered human dentine were extracted using all solutions over 14 days. Extracts were analysed for concentrations of non-collagenous proteins (NCPs) and glycosaminoglycans (GAGs), and protein profiles were examined using 1D-polyacrylamide gel electrophoresis (1D-PAGE). ELISAs for TGF-beta1 and adrenomedullin (ADM) were also performed. RESULTS: Aluminium, calcium, potassium, and sodium ions were detected in both white and grey MTA solutions. MTA and Ca(OH)(2) solutions liberated similar amounts of GAGs and NCPs although yields were considerably lower than those obtained using the EDTA solution. 1D-PAGE analysis demonstrated differences in protein profiles solubilised from dentine for all solutions. All extracts contained TGF-beta1 and ADM, EDTA solution liberated significantly greater amounts of TGF-beta1, and Ca(OH)(2) and grey MTA solutions released more ADM. CONCLUSIONS: These data imply that when placed clinically soluble components of set and setting MTA may release dentine matrix components that potentially influence cellular events for dentine repair and regeneration.

Performance of ultrasonic retrograde systems.

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<0.0001). This study showed that there is significant variability in the power output between generators, and not all Analytic handpieces performed consistently when compared with each other.

Management of peri-implant bone loss using guided bone regeneration: a clinical report.

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.