Appraisal of the IADT fellowship - A member survey

BACKGROUND/AIM

The International Association of Dental Traumatology (IADT) is considered the foremost authority in Dental Traumatology. Fellowship status was introduced in 2015 and is considered an international standard of excellence. The Fellowship Committee of the IADT believed it was essential to survey members seeking information on the benefits of the IADT Fellowship and potential considerations for future development. This survey aimed to explore the perceptions of members of IADT surrounding the fellowship process in terms of interest, accessibility, equality, perceived prestige, and value to the membership.

MATERIAL AND METHODS

The survey was sent to 546 IADT members, of whom 89 were fellows (as of 31 July 2022) from 74 countries via an email invitation. Answers were analysed using the Chi2 and Fisher's exact test (p < .05).

RESULTS

The response rate to the survey was 20.69% (n = 113), including 28 fellows (24.78%). Forty-six respondents (40.71%) were female, and 67 (59.30%) were male. Dentists identified as specialists were significantly more likely to be involved in teaching dental trauma (p = .000008). A majority of respondents (87.76%; 86/98) expressed interest in obtaining fellowship, with increased interest from more recent graduates. Learning opportunities, obtaining expertise, networking and a sense of community and prestige, were key factors in considering fellowship. There was interest in alternate pathways other than examination alone, with 60.2% of 98 respondents suggesting a combination of publications /service to IADT/ reviewer for Dental Traumatology, 57.14% suggesting the submission of case reports, and 42.86% suggesting Honorary Fellowship. Respondents (73%) were willing to participate in online discussion forums and other professional development opportunities. This preference was more notable among non-fellows (75.29%) than fellows (67.85%).

CONCLUSIONS

The survey indicates the diverse motivations and perceptions regarding the IADT Fellowship, despite the low participation of IADT members. Achieving fellowship status is desired by 87.7% of non-fellows. The majority of respondents were aware of the process, but main concerns were identified as eligibility criteria and examination difficulty. Options for alternate pathways and other initiatives promoting engagement were identified. Further exploration of these issues is required to be representative of the entire IADT membership. Addressing these obstacles could significantly enhance fellowship participation and overall member satisfaction within the IADT community.

Treatment outcomes of regenerative endodontic procedures in nonvital mature permanent teeth: a retrospective study

OBJECTIVES

This retrospective study was undertaken to clinically and radiographically evaluate the long-term outcomes of regenerative endodontic procedures (REPs) for nonvital mature permanent teeth, to analyze predictors influencing treatment outcomes.

METHODS

Nonvital mature permanent teeth treated by REPs with a minimum follow-up period of 6 months were included from 2015 to 2017. Treatment outcomes were categorized as success and failure. The periapical status and lesion healing were assessed in terms of the periapical index (PAI) and the percentage changes in periapical radiolucency (PARL) area. The clinical and radiographic outcomes of REPs were assessed by Mann-Whitney test at different follow-up period. Kaplan-Meier curves and Univariate Cox regression analysis were conducted to assess the success and identify potential predictors affecting outcomes, respectively.

RESULTS

A total of 37 mature teeth with an average follow-up of 4.3 years satisfied the criteria, and 89.2% of the teeth had a successful outcome. Significant differences in PAI scores were found between each period with respect to the baseline (p < .05). Among different periods, there was a significant difference between intervals of 3-6 months and 7-12 months (p = .039) and no significant difference between each interval of more than 12 months (p > .05). Eighty-seven percent of teeth with preoperative PARL presented completely healed. REPs significantly decreased the PARL area at the interval of 7-12 months compared to 3-6 months (p = .025), with no significant difference between each interval of more than 12 months (p > .05). No significant predictor was found for the success of outcome (p > .05). Thirteen teeth (35.1%) regained pulp sensibility, and 40.5% of the teeth exhibited intracanal calcification.

CONCLUSIONS

Within the limitations of this study, REPs provided a high long-term success rate and promoted the resolution of PARL as a biologically-based alternative treatment option for nonvital mature teeth.

CLINICAL RELEVANCE

REPs provide a high long-term success rate and promoted healing of apical periodontitis comparable with reported outcomes for root canal therapy of mature teeth.

Vital pulp therapy for permanent teeth with diagnosis of irreversible pulpitis: biological basis and outcome

Root canal treatment (RCT) has been considered the conventional standard for the management of teeth with carious pulp exposure, particularly in mature teeth presenting with symptoms. Following a better understanding of the histopathology of deep carious lesions, the histology of the cariously exposed pulp and the healing potential of the inflamed pulp, vital pulp therapy (VPT) is increasingly adopted around the world for the management of permanent teeth with clinical signs and symptoms indicative of irreversible pulpitis. Furthermore, VPT became a recognized treatment modality by the European Society of Endodontology (ESE) and the American Association of Endodontists (AAE) by virtue of its high success rates reported in outcome studies using contemporary hydraulic calcium silicate-based cements. However, proper case selection, strict asepsis, capping materials and good coronal seal are mandatory for success. The aim of this paper is to review the biological basis for VPT in symptomatic teeth with carious pulp exposure and to report on the outcome of pulpotomy in teeth with clinical diagnosis of irreversible pulpitis.

Clinical and Radiographic Outcomes of Regenerative Endodontic Procedures for Traumatized Permanent Necrotic Teeth with Apical Periodontitis and External Root Resorption

AIM

This clinical study was undertaken to assess the effect of treatment with REPs on 20 teeth with pulp necrosis, apical periodontitis and external root resorption. (ERR).

METHODOLOGY

Teeth were treated with REPS utilizing the American Association of Endodontists (AAE) protocol. Quantitative assessment of changes in radiographic root area (RRA) were statistically analyzed to assess changes in root dimensions after an average follow-up period of 3 years.

RESULTS

All 20 teeth survived, 14 teeth (70%) were classified successful, and only1 tooth (5%) failed throughout the study period. Based on the radiographic examination, all 20 teeth showed complete repair of the periapical lesions and arrested ERR. However, 5 teeth (25%) subsequently developed replacement resorption. The RRA between baseline and 3-year follow-up showed a significant difference for the total 20 teeth (p = 0.009). An analysis according to the trauma type and the extra-oral time showed the RRA increase was significantly different in the non-avulsion group (p = 0.015) and for the avulsion group with an extra-oral time less than 60 min (p = 0.029). The RRA increase was not statistically significant in the avulsion group of extra-oral time more than 60 min (p = 0.405). Nine teeth (45%) and 10 teeth (50%) responded to cold and electric pulp testing respectively.

CONCLUSIONS

Within the limitations of this study, the favourable outcomes of REPs were further confirmed for traumatized permanent necrotic teeth with ERR in terms of periapical lesion healed and a significant increase in RRA. The study contributes further evidence of the role of REPs in arresting ERR.

Retrospective analysis of the outcomes of pulpotomies in traumatised permanent anterior teeth

BACKGROUND/AIM

Complicated crown fractures are frequently encountered in the paediatric population and pulpotomy procedures (either partial or coronal) are recommended to maintain the pulp. The aim of this study was to determine the pulp outcomes of permanent teeth with complicated crown fractures treated with pulpotomy in a hospital-setting and to identify potential factors which may influence the outcomes.

MATERIAL AND METHODS

Data for this retrospective study were extracted from dental records of patients with complicated crown fractures and treated with pulpotomies at a single centre between 1 January 2015 and 30 August 2019. Pulp outcomes were determined, and the associations between the outcome and independent variables were assessed using the Chi-Square test of independence and the Point-Biserial Correlation Test. Predictors of outcome were identified using the binary logistic regression model.

RESULTS

The overall success of pulpotomy in managing traumatised permanent teeth was 61%, which was lower than those previously reported. Pulp healing was seen in 54.1% and 73.7% of teeth treated with partial pulpotomies and coronal pulpotomies, respectively. The presence of a radiographically detectable dentine bridge (p < .01) and longer clinical experience of the clinician (p < .04) was significantly associated with successful outcomes. The history of pain and the stage of root development were identified as significant predictors of the outcome.

CONCLUSION

Pulpotomy is a viable treatment modality for complicated crown fractures in the paediatric population. However, appropriate case selection and further training may be required to ensure improved pulp healing outcomes. A longer follow-up period should be considered to identify late-stage complications.

Present status and future directions - Managing discoloured teeth

Managing tooth discolouration involves a range of different protocols for clinicians and patients in order to achieve an aesthetic result. There is an increasing public awareness in the appearance of their teeth and management of tooth discolouration may be inter-disciplinary and involve both vital and nonvital teeth. Vital teeth can be easily treated with low concentration hydrogen peroxide products safely and effectively using an external approach and trays. For endodontically treated teeth, the walking bleach technique with hydrogen releasing peroxide products is popular. However, there is an association with external cervical root resorption with higher concentrations of hydrogen peroxide of 30%-35%. There are also regulatory considerations for the use of hydrogen peroxide in certain jurisdictions internationally. Prosthodontic treatments are more invasive and involve loss of tooth structure as well as a life cycle of further treatment in the future. This narrative review is based on searches on PubMed and the Cochrane library. Bleaching endodontically treated teeth can be considered a safe and effective protocol in the management of discoloured teeth. However, the association between bleaching and resorption remains unclear although there is likely to be a relation to prior trauma. It is prudent to avoid thermocatalytic approaches and to use a base/sealer to cover the root filling. An awareness expectations of patients and multidisciplinary treatment considerations is important in achieving the aesthetic result for the patient. It is likely that there will be an increasing demand for aesthetic whitening treatments. Bleaching of teeth has also become increasingly regulated although there are international differences in the use and concentration of bleaching agents.

How far have we come? A historic scoping review of dental traumatology literature

The status of the protocols used for the management of dental trauma (DT) in the eighteenth and early nineteenth-century is largely unknown. The end of World War II saw a tremendous resurgence of high quality research and the development of codes of ethics and publishing. The aim of this scoping review was to analyse articles related to aspects of DT published before 1945 in the English language. An expert group discussion was done to create an a priori protocol based on the PRISMA-2020-guidelines' extension for scoping reviews. A systematic search strategy based upon the Population (P), Exposure (E), Comparator (C), Outcome (O) and Time (T) was performed in five databases on 10 February 2022. Filters were used to identify the literature until 1945, and duplicates were removed. The scrutiny of the titles and abstracts and later the full texts was performed as per the pre-defined eligibility criteria. The grey literature and archives of the English language dentistry literature were searched, and a reference search was also performed. A total of 13 studies were selected from the databases and 20 from the reference searching. The first reported article was from the year 1872. Two other case reports had been published by 1899 and three more before World War I (1914). The majority of the studies originated from the United States of America. Nineteen were case reports, five were original research articles, two were classifications and guidelines papers, and one was a review. During the period before 1945, 33 articles were published regarding DT. The articles were mostly related to the description of cases, although there were a few original research papers. A significant observation, contrary to popular belief, was the presence of articles related to conservative management of injuries to tooth roots and the dental pulp. A progression in terms of the quality of protocols over time was also observed.

Regenerative endodontic procedures for two traumatized mature anterior teeth with transverse root fractures

Background

Regenerative endodontic procedures (REPs) are an alternative treatment in immature traumatized teeth with necrotic pulp/apical periodontitis. However, this procedure has been infrequently reported in multiple transverse root fractures of mature teeth. This case report describes management of a patient with multiple horizontal root fractures in 2 maxillary central incisors that were successfully treated with REPs.

Case presentation

A 17-year-old girl had a history of traumatic injury to mature teeth 11 and tooth 21 resulting in multiple transverse root fractures. Clinical examination showed that both teeth responded to electric and thermal pulp sensibility tests with prolonged severe pain and were tender to percussion and palpation. Periapical radiographic examination showed both teeth were fully developed and had multiple transverse fractures in the mid-root. The pulp diagnosis was consistent with symptomatic irreversible pulpitis. REPs were initiated with only the coronal fragments treated to preserve pulp vitality in the apical fragment for potential pulp tissue regeneration. After REPs, clinical signs/symptoms subsided, and the two teeth were followed for 48 months when cone beam computed tomography (CBCT) imaging was also undertaken. At the last review, the case demonstrated root fractures healing with calcified tissue and pulp calcification in the apical fragments. Both teeth were stable and in function.

Conclusions

REPs have the potential to be used to treat traumatized and symptomatic mature permanent teeth that have sustained transverse root fractures.

Ingrowth of Mineralized Tissue into the Root Canal of Immature Permanent Teeth after a Traumatic Injury: A Report of 3 Cases

The aim of this case series was to describe the endodontic management of 3 immature permanent teeth that sustained traumatic injuries and subsequently presented with complete ingrowth of mineralized tissue into the canal space. Ingrowth of bone/mineralized tissue into the canal has been considered a poor long-term outcome with an inherent risk of ankylosis. In cases 1 and 2, no endodontic treatment was undertaken, except for emergency management requiring splinting. The cases were followed for 36 and 23 months, respectively. No ankylosis was evident over the review period, and normal teeth eruption was apparent. In case 1, the tooth was treated orthodontically and was responsive to pulp sensibility testing. In both cases, there was an appearance of an internal periodontal ligament-like space on the inner root wall of the canal. In case 3, 2 years postinjury, pulp necrosis and apical periodontitis occurred, and the tooth was managed with regenerative endodontic treatment consistent with the European Society of Endodontology and the American Association of Endodontists guidelines/recommendations for a regenerative procedure. The case was followed for 8 years after regenerative endodontic treatment. No ankylosis was noted with normal eruption of the teeth. The tooth was responsive to pulp sensibility testing despite the ingrowth of mineralized tissue, which was confirmed clinically.

Clinical cell-based versus cell-free regenerative endodontics: clarification of concept and term

There is no consensus on the true meaning of clinical regenerative endodontics, and there is confusion over the concept and the term. Commonly used terms include revitalization and revascularization. The clinical methods for endodontic revitalization procedures and the tissue engineering concept differ depending on whether there is exogenous delivery of cells - called cell therapy, or not. Here, in this review, the difference is clarified by emphasizing the correct terminology: cell-free versus cell-based regenerative endodontic therapy (CF-RET versus CB-RET). The revitalization procedures practised clinically do not fit into the modern tissue engineering concepts of pulp regeneration but can be categorized as CF-RET. The modern tissue engineering concept in pulp regeneration is a CB-RET, which so far is at the clinical trial stage. However, histological examination of teeth following regenerative endodontic treatments reveals healing with repair derived from stem cells that originate from the periodontal, bone and other tissues. The aim of regenerative endodontics is regeneration of the pulp-dentine complex. This review discusses why CF-RET is unlikely to regenerate a pulp-dentine complex with current protocols. The American Association of Endodontists and the European Society of Endodontology have not yet recommended autologous stem cell transplantation (CB-RERT) which aspires for regeneration. Therefore, an understanding of the concept, term, difficulties and differences in current protocols is important for the clinician. However, rather than being discouraged that ideal regeneration has not been achieved to date, repair can be an acceptable outcome in clinical regenerative endodontics as it has also been accepted in medicine. Repair should also be considered in the context that resolution of the clinical signs/symptoms of pulp necrosis/apical periodontitis is generally reliably obtained in clinical regenerative endodontics.

Multiple assessment methodologies in determining the antibiofilm actions of sodium hypochlorite mixed with clodronate or etidronate in endodontic irrigation

This study aimed to use multiple methodologies, including a novel usage of scanning electron microscopy (SEM), to evaluate the antimicrobial actions of sodium hypochlorite (NaOCl) admixed with clodronate or etidronate in root canal irrigation. The study also examined the usefulness of colony counting as a biofilm assessment methodology. Seven day Enterococcus faecalis biofilms were grown on hydroxyapatite discs. The discs were disinfected with 0.26 M clodronate-5% NaOCl, 0.26 M etidronate-5% NaOCl, 5% NaOCl, or treated with phosphate buffered saline (PBS). Assessments were performed using colony counting, SEM and the XTT reduction assay. The XTT assessment used the same groups but with 2.5% NaOCl. For colony counting, bacteria were removed from the discs by vortex mixing, followed by plating. The discs were subsequently fixed for SEM imagining and evaluators scored the SEM micrographs for remaining bacteria. Antibiofilm actions were assessed with the Kruskal-Wallis and Dunn's multiple comparison tests. SEM micrographs and the XTT assay revealed no differences between the NaOCl controls and the clodronate or etidronate mixtures with NaOCl (P > 0.05). It was concluded that the chelator mixtures with NaOCl had antibiofilm actions comparable to NaOCl. Furthermore, vortex mixing incompletely removed biofilm from HA discs in the PBS controls and hence colony counting using E. faecalis biofilms on hydroxyapatite discs could not be used for intergroup comparisons involving PBS. Additionally, colony counting could not be used for comparisons between the NaOCl treatment groups because the removal of bacteria from the substrate by vortex mixing was affected by the irrigant type.

Resistance to compressive force in continuous chelation

Continuous chelation involves the simultaneous use of sodium hypochlorite and a chelating agent. Given the combination of a proteolytic agent and a demineralising chelator, this study aimed to investigate whether mixtures containing the weak chelators etidronate or clodronate and sodium hypochlorite could adversely affect the mechanical strength of teeth compared to the sequence sodium hypochlorite/EDTA/sodium hypochlorite. Matching pairs of bovine teeth were tested on a universal testing machine, and the compressive load at fracture was recorded. One root from each pair was prepared with the sequence, and the matching tooth was prepared with either water, the clodronate mixture or the etidronate mixture. No differences in load at fracture were seen between either mixture and the sequence. However, loads were higher in the teeth irrigated with water compared to the sequence. The results indicated that the continuous chelation mixtures did not alter tooth mechanical properties compared to the standard sequence.

Modified Apexification Procedure for Immature Permanent Teeth with a Necrotic Pulp/Apical Periodontitis: A Case Series

The current American Association of Endodontists clinical considerations for a regenerative endodontic procedure state that a regenerative procedure is suitable for immature permanent teeth with necrotic pulp when the pulp space is not needed for a post/core in the final restoration. Therefore, many immature permanent teeth with necrotic pulp that have sustained a substantial loss of coronal tooth structure either from caries or trauma are treated by apexification or mineral trioxide aggregate/Biodentine (Septodent, Lancaster, PA) apical barrier techniques in which no further root maturation would occur. This case series presents 10 immature permanent teeth with necrotic pulp in which a post/core was likely required in the future for adequate coronal restoration because of loss of substantial coronal tooth structure and a modified apexification procedure was used. All 10 cases after the modified apexification procedure showed no clinical symptoms/signs and showed radiographic evidence of healed/healing of periapical lesion after a 2-year review. Eight cases showed increased thickness of the apical root canal walls, increased apical root length, and apical closure. The overall percentage change in root length was 7.52%, in root width at the apical one third it was 18.89%, and in radiographic root area it was 15.04% at the 24- to 72-month follow-up period. This modified apexification procedure allows for the tooth to be restored with a post/core if required for the final restoration in the future as well as continued root development.

Limited Evidence Suggests Benefits of Single Visit Revascularization Endodontic Procedures - A Systematic Review

Abstract Revascularization endodontic procedures commonly require multiple treatment sessions. However, single visit procedures may be advantageous from the clinical and patient management standpoints. The purpose of this review was to evaluate the outcomes of single-visit revascularization endodontic procedures for the management of immature permanent teeth with non-vital pulp. Two electronic databases (Scopus and PubMed) were searched, from their inception to July 2018, for studies that assessed clinical and/or radiographic and/or histologic outcomes of single-visit revascularization endodontic procedures performed in immature permanent teeth with non-vital pulp. Case reports, animal studies and clinical trials were included. The quality of case reports was appraised by Joanna Briggs Institute Critical Appraisal Checklist for Case Reports. The quality of randomized clinical trials was assessed by the revised Cochrane risk of bias tool for randomized trials. The risk of bias for animal studies was assessed using SYRCLE’s risk of bias tool. Tabulation followed by narrative synthesis was used to draw conclusions. Seven studies satisfied the selection criteria. Five were classified as case reports, one as a randomized clinical trial and one as animal study. The latter presented with a high risk of bias, whilst the remaining showed a low risk. The evidence supporting the potential use of single-visit revascularization endodontic procedures is scarce. Successful single-visit revascularization endodontic procedures commonly include the use of high concentrations of sodium hypochlorite and EDTA combined with the use of agitation systems. Further clinical trials with long term follow up are needed to confirm the results of the current review.

Plasma phospholipid fatty acids are associated with altered fibrin clot properties in a population-based setting

Evidence regarding the relationship of plasma clot properties with fatty acids is contradictory, owing to different experimental protocols employed. The relationship of fibrinogen and plasma fibrin clot properties with plasma phospholipid fatty acids were cross-sectionally investigated in a population-based setting in 900 individuals. Composite saturated fatty acids (driven by stearic acid) and composite n-3 and n-6 polyunsaturated fatty acids (driven by docosahexaenoic and arachidonic acid respectively) were associated with prothrombotic clot properties. Composite monounsaturated fatty acids (driven by oleic acid) were associated with a profibrinolytic clot phenotype. Fibrinogen and BMI partly mediated these relationships. Individual plasma fatty acids from the same composite group had opposing associations with clot properties indicating that associations with composite fatty acid groups is dependent on the relative composition of the comprising fatty acids. The relationship of the plasma phospholipid fatty acid profile with disease should not be interpreted without considering the role of regulatory mechanisms.

Regenerative endodontics: a comprehensive review

The European Society of Endodontology and the American Association for Endodontists have released position statements and clinical considerations for regenerative endodontics. There is increasing literature on this field since the initial reports of Iwaya et al. (Dental Traumatology, 17, 2001, 185) and Banchs & Trope (Journal of Endodontics, 30, 2004, 196). Endogenous stem cells from an induced periapical bleeding and scaffolds using blood clot, platelet rich plasma or platelet-rich fibrin have been utilized in regenerative endodontics. This approach has been described as a 'paradigm shift' and considered the first treatment option for immature teeth with pulp necrosis. There are three treatment outcomes of regenerative endodontics; (i) resolution of clinical signs and symptoms; (ii) further root maturation; and (iii) return of neurogenesis. It is known that results are variable for these objectives, and true regeneration of the pulp/dentine complex is not achieved. Repair derived primarily from the periodontal and osseous tissues has been shown histologically. It is hoped that with the concept of tissue engineering, namely stem cells, scaffolds and signalling molecules, that true pulp regeneration is an achievable goal. This review discusses current knowledge as well as future directions for regenerative endodontics. Patient-centred outcomes such as tooth discolouration and possibly more appointments with the potential for adverse effects needs to be discussed with patients and parents. Based on the classification of Cvek (Endodontics and Dental Traumatology, 8, 1992, 45), it is proposed that regenerative endodontics should be considered for teeth with incomplete root formation although teeth with near or complete root formation may be more suited for conventional endodontic therapy or MTA barrier techniques. However, much is still not known about clinical and biological aspects of regenerative endodontics.

Rheological Characterization as an Alternative Method to Indentation for Determining the Setting Time of Restorative and Endodontic Cements

This study explored an alternative approach using rheology to assess setting time. The following cements were tested: ProRoot^® MTA (Dentsply, Tulsa, OK, USA), Biodentine^® (Septodont, Saint Maur des Fosses, France), Fuji VII^®, FujiVII^® EP, and Fuji IX^® (from GC Corporation, Tokyo, Japan), RealSeal SE™ Sealer (SybronEndo, Amersfoort, The Netherlands), AH 26^® and AH Plus (both from Dentsply DeTrey, Konstanz, Germany). Freshly mixed cements were placed into a strain-controlled rheometer (1 rad·s^-1 with an applied strain of 0.01%). From measurements of elastic modulus over time, the time taken to reach 90% of the plateau elastic modulus (designated as the setting time) was determined for each cement. In increasing order, the setting times were as follows: Fuji VII EP 3.3 min, Fuji VII 3.6 min, Fuji IX 3.7 min, ProRoot MTA 5.1 min, Biodentine 15.9 min, RealSeal 22.2 min, AH Plus 5933 min, and AH 26 5067 min. However, ProRoot MTA did not yield reliable results. The time to reach the 90% plateau elastic modulus correlates well with the setting time of glass ionomer cements and Biodentine. Using this approach gives much longer setting times for endodontic sealers than previously recognized.

Alkaline Material Effects on Roots of Teeth

The aim of this review was to identify and analyse all studies related to the effects of alkaline materials used in dentistry on roots of teeth. The first part of the review focused on mechanical property alterations of root dentine due to sodium hypochlorite (SH) used as an irrigant solution based on MeSH (Medical Subject Heading) terms from a previous study by Pascon et al in 2009. The second part reviewed literature on calcium hydroxide (CH), mineral trioxide aggregate (MTA) and other alkaline materials used as root canal dressings or filling materials. Additional MeSH terms used included "compressive strength", "elastic modulus" "flexural strength", "fracture strength" and "fracture resistance". The language filter was English. Of the initial 205 articles identified, 49 were included in this review, of which 29 were on SH, 21 on CH/MTA, and 1 relating to both. Many in vitro studies indicated a strong link between reduced mechanical properties of roots of teeth or radicular dentine treated with SH, and when sealers or root fillings with CH- or MTA-based materials were placed in contact with roots or radicular dentine. Recent literature indicates that the association between reduced mechanical properties and alkaline sealers and/or root-filling materials is not as straightforward as previously assumed, and requires further investigation using more valid experimental models.

Alkaline Materials and Regenerative Endodontics: A Review

Periapical health is the primary goal of endodontic treatment in mature and immature teeth. In addition, the goals of treatment of immature teeth with arrested root development include root growth to length and maturation of the apex, as well as thickening of the canal wall. These goals are valid for immature teeth that have been subjected to trauma and dental caries or that are the result of developmental anomalies that expose the tooth to the risk of pulp necrosis and consequently result in the cessation of root maturation. Regenerative endodontic procedures (REPs) have been described as a “paradigm shift” in the treatment of immature teeth with pulp necrosis and underdeveloped roots, as there is the potential for further root maturation and return of vitality. Treatment with REPs is advocated as the treatment of choice for immature teeth with pulp necrosis. REP protocols involve the use of alkaline biomaterials, primarily sodium hypochlorite, calcium hydroxide, mineral trioxide aggregates and Biodentine, and are the essential components of a successful treatment regimen.

A review of regenerative endodontics: current protocols and future directions

This review outlines the biological basis and clinical protocols currently used in regenerative endodontic procedures (REPs) and discuss future directions in pulp regeneration approaches. The treatment of immature teeth with REPs has been described as a ‘paradigm shift’ as there is the potential for further root maturation. Clinically, REPs involve disinfection of the root canal system without damaging the endogenous stem cell potential present in the apical papilla and other tissues. These stems cells are introduced into the root canal space by inducing a blood clot followed by placement of an intracanal barrier to prevent microleakage. The biological concept of REPs involves the triad of stem cells, scaffold and signalling molecules. Currently, repair rather than true regeneration of the ‘pulp-dentine complex’ is achieved and further root maturation is variable. However, may clinicians consider the treatment of teeth with REPs as the optimal treatment approach for immature teeth with pulp necrosis.

Mineral Trioxide Aggregate-A Review of Properties and Testing Methodologies

Mineral trioxide aggregate (MTA) restoratives and MTA sealers are commonly used in endodontics. Commonly referenced standards for testing of MTA are ISO 6876, 9917-1 and 10993. A PubMed search was performed relating to the relevant tests within each ISO and "mineral trioxide aggregate". MTA restoratives are typically tested with a mixture of tests from multiple standards. As the setting of MTA is dependent upon hydration, the results of various MTA restoratives and sealers are dependent upon the curing methodology. This includes physical properties after mixing, physical properties after setting and biocompatibility. The tests of flow, film thickness, working time and setting time can be superseded by rheology as it details how MTA hydrates. Physical property tests should replicate physiological conditions, i.e. 37 °C and submerged in physiological solution. Biocompatibility tests should involve immediate placement of samples immediately after mixing rather than being cured prior to placement as this does not replicate clinical usage. Biocompatibility tests should seek to replicate physiological conditions with MTA tested immediately after mixing.

Classification and Nomenclature of Commercial Hygroscopic Dental Cements

Objective

Under the Global Medical Device Nomenclature (GMDN) system, the newly introduced term 'hygroscopic dental cement' (HDC) encompasses MTA as well as cements based on bioceramics, calcium silicate or calcium sulphate. Many HDCs have a long history of use in dentistry. There is a need for a consistent, logical and informed approach to the nomenclature of traditional and novel HDCs.

Methods

Commercial manufacturers of HDC were contacted requesting information on the compositions of products. Manufacturers that were unknown to the authors, that were unable to be contacted, that wished to be excluded from this paper, or that did not send their information on compositions in due time were not included.

Results

The compositions of commercial HDCs include various hybrids of calcium silicates, calcium aluminates, calcium phosphates, calcium sulphate as well as zinc sulphates. Furthermore, there are variations in the radiopacifier as well as additives that change the handling or setting processes.

Conclusion

The inclusion of different additives to HDCs enables variation in handling properties such that they now exist as distinct putties and sealers as well as cements.

Dental Material Choices for Pulp Therapy in Paediatric Dentistry

Objective:

The purpose of this study was to assess the restorative choices for pulpal therapy by members of the Australian and New Zealand Society of Paediatric Dentistry (ANZSPD).

Methods:

Members of the ANZSPD were sent an online survey asking about the procedures that they performed and their choice of dental materials.

Results:

The respondents were 31 general dentists (GD) and 55 specialist paediatric dentists (PD). Materials used for indirect pulp capping included calcium hydroxide [Ca(OH)₂] cement (CHC), glass ionomer cement or resin-modified glass ionomer cement (GIC/RMGIC), Ca(OH)₂ paste (CHP) and mineral trioxide aggregate (MTA). Materials for direct pulp capping included MTA, CHP and CHC. Materials and techniques used for pulpotomy included MTA, ferric sulphate, formocresol and diathermy, CHP and CHC. GD and PD were similar in their choice of materials. However, there was no preferred product for pulp therapy. Most GD learnt how to use MTA from CPD lectures, while some PD learnt how to use MTA from their postgraduate training as well as CPD lectures. Many GD and PD did not have hands-on training from their education on how to use MTA (GD: 80%, PD: 43%). Most would like to attend hands-on MTA courses (GD: 86%, PD: 65%).

Conclusion:

There was no clear preferred product for the various types of pulp therapy in paediatric dentistry. Education appears to be the major barrier to the use of MTA rather than the cost of MTA.

Endodontic Treatment Outcomes

The primary goal of conventional endodontic treatment is prevention and/or elimination of apical periodontitis for both mature permanent teeth and immature teeth with an open apex. Besides these goals, the objectives of endodontic treatment of immature teeth include preservation of pulp vitality and often further root maturation. Robust criteria for outcome assessment are an essential determinant for any measure of treatment success for both mature and immature teeth.

The influence of particle size and curing conditions on testing mineral trioxide aggregate cement

Objectives: To assess the effects on curing conditions (dry versus submerged curing) and particle size on the compressive strength (CS) and flexural strength (FS) of set MTA cement.

Materials and methods: Two different Portland cements were created, P1 and P2, with P1 < P2 in particle size. These were then used to create two experimental MTA products, M1 and M2, with M1 < M2 in particle size. Particle size analysis was performed according to ISO 13320. The particle size at the 90th percentile (i.e. the larger particles) was P1: 15.2 μm, P2: 29.1 μm, M1: 16.5 μm, and M2: 37.1 μm. M2 was cured exposed to air, or submerged in fluids of pH 5.0, 7.2 (PBS), or 7.5 for 1 week. CS and FS of the set cement were determined using a modified ISO 9917-1 and ISO 4049 methods, respectively. P1, P2, M1 and M2 were cured in PBS at physiological pH (7.2) and likewise tested for CS and FS.

Results: Curing under dry conditions gave a significantly lower CS than when cured in PBS. There was a trend for lower FS for dry versus wet curing. However, this did not reach statistical significance. Cements with smaller particle sizes showed greater CS and FS at 1 day than those with larger particle sizes. However, this advantage was lost over the following 1–3 weeks.

Conclusions: Experiments that test the properties of MTA should cure the MTA under wet conditions and at physiological pH.

Methodologies for measuring the setting times of mineral trioxide aggregate and Portland cement products used in dentistry

Objective The current standard used to measure setting time for Mineral Trioxide Aggregate (MTA) involves indentation testing with arbitrary weights. This study compared indentation testing against rheological measurements and assessed the influences of particle size and the inclusion of bismuth oxide on the setting time of experimental MTA and Portland cement (PC).

Material and methods Two PCs (P1 and P2) of different particle sizes were produced using the same clinker. From these two PCs, two experimental MTAs (M1 and M2) were created with the addition of bismuth oxide. Particle size distributions were assessed using laser diffraction analysis. Indentation setting time tests were performed in accordance to the Gillmore needle test. Elastic modulus was assessed using a strain-controlled rheometer at 1 rad s⁻¹ and an applied strain of 0.01%.

Results P1, P2, M1 and M2 cements had median particle sizes of 6.1, 12.5, 6.5 and 13.0 μm, respectively. Using indentation testing, final setting times were ranked P1 < M1 < P2 < M2. The ranking of the final setting time corresponded with the rheological assessment of time required to reach 95% of the elastic modulus plateau.

Conclusions The time to reach 95% elastic modulus plateau of 9.3 min corresponds to a time close to the point where the material can be overlaid with another restorative material to give a final restoration. The 95% plateau value for elastic modulus may be a more useful parameter for determining how the setting reaction of PC and MTA cements progress over time.

Deconvolution of the particle size distribution of ProRoot MTA and MTA Angelus

Objective Mineral trioxide aggregate (MTA) cements contain two types of particles, namely Portland cement (PC) (nominally 80% w/w) and bismuth oxide (BO) (20%). This study aims to determine the particle size distribution (PSD) of PC and BO found in MTA.

Materials and methods The PSDs of ProRoot MTA (MTA-P) and MTA Angelus (MTA-A) powder were determined using laser diffraction, and compared to samples of PC (at three different particle sizes) and BO. The non-linear least squares method was used to deconvolute the PSDs into the constituents. MTA-P and MTA-A powders were also assessed with scanning electron microscopy.

Results BO showed a near Gaussian distribution for particle size, with a mode distribution peak at 10.48 μm. PC samples milled to differing degrees of fineness had mode distribution peaks from 19.31 down to 4.88 μm. MTA-P had a complex PSD composed of both fine and large PC particles, with BO at an intermediate size, whereas MTA-A had only small BO particles and large PC particles.

Conclusions The PSD of MTA cement products is bimodal or more complex, which has implications for understanding how particle size influences the overall properties of the material. Smaller particles may be reactive PC or unreactive radiopaque agent. Manufacturers should disclose particle size information for PC and radiopaque agents to prevent simplistic conclusions being drawn from statements of average particle size for MTA materials.

Diagnosis of acute dental trauma: the importance of standardized documentation: a review

In 1985 Andreasen and Andreasen published a paper on the diagnosis of luxation injuries and outlined the importance of standardized clinical, radiographic, and photographic techniques. Now 30 years later, these recommendations remain current in the International Association of Dental Traumatology (IADT) guidelines for the management of dental trauma and describe circumstances surrounding the time of injury, the extent of trauma (e.g., type of luxation injury), healing potential (e.g., stage of root development) as well as information concerning subsequent treatment. The purpose of this review was to include findings for other types of trauma and to discuss more recent studies that augment and/or improve on the original findings from 30 years ago. The present review discusses the use of a standardized clinical registration (pulpal sensibility testing, laser Doppler flowmetry, mobility testing), radiographic survey, and photographic registration of the traumatized patient. Moreover, the value of digital radiographs and recent developments in computer tomography with respect to possible enhancement of the trauma diagnosis are discussed.

D90: The Strongest Contributor to Setting Time in Mineral Trioxide Aggregate and Portland Cement

INTRODUCTION

The setting times of commercial mineral trioxide aggregate (MTA) and Portland cements vary. It was hypothesized that much of this variation was caused by differences in particle size distribution.

METHODS

Two gram samples from 11 MTA-type cements were analyzed by laser diffraction to determine their particle size distributions characterized by their percentile equivalent diameters (the 10th percentile, the median, and the 90th percentile [d90], respectively). Setting time data were received from manufacturers who performed indentation setting time tests as specified by the standards relevant to dentistry, ISO 6786 (9 respondents) or ISO 9917.1 (1 respondent), or not divulged to the authors (1 respondent). In a parallel experiment, 6 samples of different size graded Portland cements were produced using the same cement clinker. The measurement of setting time for Portland cement pastes was performed using American Society for Testing and Materials C 191. Cumulative heat release was measured using isothermal calorimetry to assess the reactions occurring during the setting of these pastes. In all experiments, linear correlations were assessed between setting times, heat release, and the 3 particle size parameters.

RESULTS

Particle size varied considerably among MTA cements. For MTA cements, d90 was the particle size characteristic showing the highest positive linear correlation with setting time (r = 0.538). For Portland cement, d90 gave an even higher linear correlation for the initial setting time (r = 0.804) and the final setting time (r = 0.873) and exhibited a strong negative linear correlation for cumulative heat release (r = 0.901).

CONCLUSIONS

Smaller particle sizes result in faster setting times, with d90 (the largest particles) being most closely correlated with the setting times of the samples.

Clinical manipulation of mineral trioxide aggregate: lessons from the construction industry and their relevance to clinical practice

Mineral trioxide aggregate (MTA) is based on ordinary Portland cement (with added radiopaque agents) and, thus, shares many of its features. Although MTA is reported to be difficult to handle clinically, concrete materials made using Portland cement are the foundation of the construction industry. In this paper, we summarize important lessons from the construction literature that are relevant to the successful use of MTA in clinical practice, including behaviour during storage, susceptibility to acidic environments, the effects of exposure of the setting material to moisture and interactions with substances that may interfere with the speed of setting and the quality of the end product.