Mineral trioxide aggregate and other bioactive endodontic cements: an updated overview - part II: other clinical applications and complications

Regenerative endodontic therapy: From laboratory bench to clinical practice

BACKGROUND

Maintaining the vitality and functionality of dental pulp is paramount for tooth integrity, longevity, and homeostasis. Aiming to treat irreversible pulpitis and necrosis, there has been a paradigm shift from conventional root canal treatment towards regenerative endodontic therapy.

AIM OF REVIEW

This extensive and multipart review presents crucial laboratory and practical issues related to pulp-dentin complex regeneration aimed towards advancing clinical translation of regenerative endodontic therapy and enhancing human life quality.

KEY SCIENTIFIC CONCEPTS OF REVIEW

In this multipart review paper, we first present a panorama of emerging potential tissue engineering strategies for pulp-dentin complex regeneration from cell transplantation and cell homing perspectives, emphasizing the critical regenerative components of stem cells, biomaterials, and conducive microenvironments. Then, this review provides details about current clinically practiced pulp regenerative/reparative approaches, including direct pulp capping and root revascularization, with a specific focus on the remaining hurdles and bright prospects in developing such therapies. Next, special attention was devoted to discussing the innovative biomimetic perspectives opened in establishing functional tissues by employing exosomes and cell aggregates, which will benefit the clinical translation of dental pulp engineering protocols. Finally, we summarize careful consideration that should be given to basic research and clinical applications of regenerative endodontics. In particular, this review article highlights significant challenges associated with residual infection and inflammation and identifies future insightful directions in creating antibacterial and immunomodulatory microenvironments so that clinicians and researchers can comprehensively understand crucial clinical aspects of regenerative endodontic procedures.

Tomographic evaluation of apexogenesis with human treated dentin matrix in young permanent molars: a split-mouth randomized controlled clinical trial

BACKGROUND

The concept of vital pulp therapy (VPT) of immature permanent teeth has evolved in recent years. There has been a great tendency towards investigating new pulp capping materials for perfect imitation for natural dentin-pulp complex formation process and restoring the normal tissue's characteristics. Therefore, this study aimed to assess the clinical and tomographic outcomes of apexogenesis with human treated dentin matrix (hTDM) compared to mineral trioxide aggregate (MTA).

MATERIALS AND METHODS

40 bilateral deep carious young mandibular first permanent molars (FPMs) in 20 healthy children aged between 6 and 8 years old were randomly allocated into 2 groups in which the FPMs treated with hTDM and MTA after pulpotomy procedure. The children were followed up clinically at 3, 6, 12, and 18 months. Tomographic evaluation was performed at baseline and 18-month evaluation period.

RESULTS

The overall clinical success rate was 100% in both groups. Regarding tomographic evaluation, the mean differences in root length, periapical diameter and area were statistically significant in each individual group but without statistically significant differences between both groups.

CONCLUSION

Human TDM hydrogel could be considered a promising pulpotomy agent for immature permanent teeth.

TRIAL REGISTRATION

The current clinical trial was recorded at clinicaltrials.gov, NCT06116695, 27/10/2023, Retrospectively registered.

Effect of indirect ultrasonic activation on the root canal obturation with premixed calcium silicate cement: an in vitro study

BACKGROUND

To assess the effect of indirect ultrasonic activation on the root canal obturation with a premixed calcium silicate cement (CSC).

METHODS

Twenty-six single-rooted premolars were sectioned to the length of 11 mm. All the roots were instrumented using ProTaper Next instruments and randomly assigned to either the control (n = 4) or experimental (n = 22) groups according to root canal obturation methods. Root specimens allocated to experimental groups were obturated with Endocem MTA, with (group EMU) or without (group EM) indirect ultrasonic activation (n = 11/group). Root specimens obturated with gutta-percha served as positive and negative (after nail varnish coating) controls. Intraoral radiograph images were used to assess the presence or absence of voids in the coronal, middle, and apical thirds of each specimen. The specimens were connected to a nanoscale fluid filtration device to measure quantitative leakage data. Data was statistically analyzed with a significance level of 0.05.

RESULTS

There was no significant difference in the voids formation between the two groups (p > 0.05), but specimens in group EMU presented significantly higher quantitative leakage than those in group EM (p < 0.05).

CONCLUSIONS

Within the limitation of this study, indirect ultrasonic activation of premixed CSC did not affect the void formation but presented higher quantitative leakage. Future research incorporating micro-CT imaging would enable a more precise and comprehensive analysis, providing valuable insights into the root canal obturation with premixed CSCs.

Biological and mechanical challenges in the endodontic treatment of immature teeth with pulp necrosis: insights based on a Series of Atypical Clinical Cases

Over the past two decades, dental pulp regeneration has become a major focus in endodontology. The currently applied clinical strategies are referred to as 'revitalisation' procedures. These biology-based treatment strategies aim at regenerating lost pulp tissues in necrotic teeth, in the absence or even more in the presence of periapical bone lesion, clinical signs and symptoms. Such approaches are generally - but not exclusively - used in immature teeth to promote root maturation, both in length and in thickness, ultimately to reduce their risk of fracture. A growing body of evidence has led to increased understanding and reliability of these treatment strategies, which are now considered as a valid alternative treatment option besides conventional ones, mainly the apical plug technique. However, all systematic reviews evaluating clinical outcomes concluded that there is a lack of robust long-term studies on the subject; most published cases of revitalisation having a relatively short-term follow-up, usually under 2 years. In this context, several major challenges remain to be addressed to better understand the promises and limitations of revitalisation procedures as compared to other treatment options, mainly the placement of an apical plug made of hydraulic calcium silicate cement. The purpose of this paper was therefore to identify some of the important remaining challenges related to such procedures, which can be broadly categorised into biological and mechanical ones, affecting treatment success and tooth survival. Meeting these challenges requires close collaboration between both researchers and clinicians, to establish guidelines, evaluate and understand treatment outcomes, and update guidelines accordingly. However, it is not always easy for researchers to understand the clinical reality faced by practitioners. In order to facilitate their mutual understanding, the aforementioned challenges were illustrated by providing clinical context through a series of atypical clinical cases with long-term follow-up (4-8 years).

The Efficacy of Surgical Techniques for the Management of Confirmed Vertical Root Fractures: A Systematic Review

The aim of the present systematic review was to evaluate the efficacy of surgical techniques for the preservation of a tooth with VRF. We included case series presenting techniques for the treatment of VRFs. Both electronic sources (MEDLINE, EMBASE, Cochrane Central) and reference lists/table of contents of pertinent journals were screened. Eight articles (six studies) were included. Four of the studies bonded the fractured fragments with 4-META/MMA-TBB resin, one adopted MTA, and in one study the authors used resin-ionomer cement. There was significant heterogeneity in the results regarding teeth survival rate and it was not possible to perform a quantitative synthesis. Scientific evidence concerning the treatment of vertically fractured roots is sparse and of low quality. Consequently, it is not possible to draw conclusions regarding the efficacy of the reported techniques. More studies with higher scientific standards may add validity to the techniques described here. Trial Registration: CRD42024524356 in PROSPERO.

Single cone and bioceramic sealer in oval canals: Efficiency endodontic obturation

Background

To compare the volume of voids in oval canals obturated with single cone and bioceramic sealer (SCBC), single cone with lateral condensation or Guttacore by means of micro- computed tomography analysis. To measure the obturation time used for each technique.

Material and Methods

65 uni-radicular teeth with an oval canal were selected. Canals were shaped with Protaper Next and divided into three groups according to the tested obturation technique. The time taken to obturate the canals was recorded. Each specimen was scanned using micro-CT at a voxel resolution of 25 µm. The volume of detected voids and volume of obturated canal was calculated in relation to the total volume. Voids were classified according to their location in the radicular thirds. 2D images obtained were used to calculate the percentage of filled area and percentage of voids. ANOVA test was used to assess significant differences in voids detected in the root thirds and obturation time. Multiple comparisons were made with the Bonferroni test. To analyze the root thirds Kruskal-Wallis was used and for pairwise comparisons Mann-Whitney with Bonferroni modification.

Results

The highest percentage of void volume and void area was found in the single cone group with lateral condensation technique. These differences were significant in the apical third (p<0,01). SCBC was significantly faster (p<0.001).

Conclusions

The three-obturation techniques achieved low void rates. SCBC had the least number of voids and was the fastest obturation technique. Clinical Relevance: In oval canals the quality of obturation carried out with these techniques were suitable and clinically acceptable. SCBC was the most efficient obturation technique. Key words:Bioceramic sealer, Oval canals, Single cone technique, Root canal filling, Micro-CT analysis, Guttacore Obturator.

Periapically Extruded Calcium Silicate Cements in Retreated Teeth: A Case Report and Literature Review

Calcium silicate-based materials, known for their bioactive properties, are increasingly being used in endodontic therapy. Accidental extrusion of these materials into the periapical tissue is a relatively common phenomenon that can impede periapical healing. The aim of this article is to present three endodontically retreated case reports with moderate to extensive periapical lesions and to review the literature on this topic. The comprehensive search and analysis of the relevant literature included a review of 51 articles, of which nine case reports/series from 2010 to 2023 were considered. Based on the summarized data, over 80% of the retreated cases showed complete healing of the periapical lesions, while the success rate in initially treated teeth was over 90%. Healing of periapical lesions is the most common therapeutic outcome, even in cases where extrusion occurs. Despite this conclusion, extrusion of materials into periapical tissues should be avoided. Further case reports on the extrusion of calcium silicate-based materials other than MTA are recommended. When evaluating the success rate of periapical healing in such cases, it is recommended to extend the follow-up periods to several years.

Cytotoxicity and proliferation effects of cold ceramic on stem cells from human exfoliated deciduous teeth compared to MTA: an in vitro study

BACKGROUND

This study aimed to assess the cytotoxicity and proliferation effects of cold ceramic (CC) on stem cells from human exfoliated deciduous teeth(SHEDs) compared to mineral trioxide aggregate(MTA).

METHODS

In this in vitro study, the cytotoxicity of fresh and set MTA and CC for SHEDs was assessed after 24 and 72 h using the methyl thiazolyl tetrazolium(MTT) assay. The scratch test was used to evaluate cell migration, while cell morphology and adhesion were assessed by scanning electron microscopy (SEM). Data were analyzed by one-way ANOVA and Tukey test (alpha = 0.05).

RESULTS

At 24 h, the cell viability percentage was higher in fresh MTA than fresh CC (P < 0.0001), and in set CC than set MTA (P = 0.0003). At 72 h, cell viability in the presence of both fresh and set MTA was similar to the control group (P = 0.871). Set CC showed significantly higher cell viability (P < 0.0001) while fresh CC decreased cell viability. The scratch was completely healed in the control group. Cell density was lower in the MTA group, and the lowest in the CC group. SHEDs preserved their natural morphology and had optimal cytoplasmic attachment to MTA and CC surfaces after 24 and 48 h.

CONCLUSION

Cell viability and migration in CC were comparable to those in MTA and even superior in set form after 72 h. CC caused cell proliferation in addition to migration. Cells had a normal morphology and optimal adhesion in both groups. CC may be suitable for use as an alternative to MTA in pulpotomy of primary teeth.

CLINICAL TRIAL NUMBER

Not applicable.

Postoperative Outcomes in Surgical Endodontic Treatment Using Various Root-End Filling Materials for Immature Root Apices

The present case series describes the postoperative outcomes of surgical endodontic treatment in teeth with immature root apices using different root-end filling materials. Three cases involving young patients with discolored and non-vital teeth were treated using varied approaches: no root-end filling, mineral trioxide aggregate (MTA), and Biodentine (Septodont, Saint-Maur-des-Fossés, France). Each case included comprehensive pre-surgical assessments, conservative non-surgical root canal treatments, and periapical surgeries performed under magnification. The outcomes were evaluated based on clinical and radiographic success over follow-up periods ranging from six to 24 months. Results demonstrated favorable healing and functional restoration across all cases, highlighting the importance of individualized treatment plans, meticulous surgical techniques, and rigorous postoperative care. The findings underscore the efficacy of contemporary root-end filling materials like MTA and Biodentine in promoting periapical healing and bone regeneration while also emphasizing the necessity for personalized approaches in managing immature root apices. Further research is recommended to optimize these treatment protocols.

Bioactive Materials in Vital Pulp Therapy: Promoting Dental Pulp Repair Through Inflammation Modulation

With the paradigm shift towards minimally invasive biologic therapies, vital pulp therapy (VPT) has been receiving increasing attention. Currently, bioactive materials (BMs), including MTAs, Biodentine, Bioaggregate, and iRoot BP Plus, are clinically widely used for the repair of damaged pulp tissue. Emerging evidence highlights the crucial role of inflammation in pulp repair, with mild to moderate inflammation serving as a prerequisite for promoting pulp repair. BMs play a pivotal role in regulating the balance between inflammatory response and reparative events for dentine repair. Despite their widespread application as pulp-capping agents, the precise mechanisms underlying the actions of BMs remain poorly understood. A comprehensive literature review was conducted, covering studies on the inflammatory responses induced by BMs published up to December 2023. Sources were identified through searches of PubMed and MEDLINE databases, supplemented by manual review of cross-references from relevant studies. The purpose of this article is to discuss diverse mechanisms by which BMs may regulate the balance between tissue inflammation and repair. A deeper understanding of these regulatory mechanisms will facilitate the optimization of current pulp-capping agents, enabling the development of targeted regenerative strategies to achieve superior clinical outcomes.

Effect of Bio MTA plus & ProRoot MTA pulp capping materials on the regenerative properties of human dental pulp stem cells

The aim of the present study was to investigate the effects of the biological properties of hDPSCs exposed to Bio MTA+ & ProRoot MTA pulp capping materials on the proliferation and odontogenic differentiation of hDPSCs. Human dental pulp stem cells (hDPSCs) were isolated from impacted third molars. Extracts of Bio MTA + and ProRoot MTA were prepared at a 1:1 ratio. The effects of the extracts on hDPSCs cytotoxicity and proliferation were assessed via a CCK-8 assay. Annexin V expression was investigated to assess the effects of both materials on the induction of apoptosis. The effects of ProRoot MTA and Bio MTA + extraction media on the stemness properties of hDPSCs were assessed via real-time quantitative PCR, and the expression of odontogenic markers (RUNX2, DMP1 & DSSP) was analyzed via RT‒PCR Alizarin Red staining. Cells exposed to Bio MTA + had the greatest degree of proliferation. The results of Annexin V staining indicated that Bio MTA + caused the least amount of apoptosis. RUNX2, DMP1 and DSSP were highly expressed by Bio MTA + and indicated successful odontogenic differentiation. Compared with ProRoot MTA, Bio MTA + exhibited an exceptional level of cytocompatibility, as well as advantageous bioactivities, including the preservation of stemness and an increase in the proliferation capacity of hDPSCs. In addition, it demonstrated favorable bioactive properties by stimulating odontogenic differentiation. Bio MTA + offers significant advantages in terms of biocompatibility, bioactivity, and regenerative potential, making it an excellent choice for procedures aimed at preserving or regenerating dental pulp tissue. However, additional research is required to address the lack of in vivo validation, as replicating physiological conditions is crucial for accurately assessing clinical outcomes and comparing them with results obtained from in vitro experiments.

A 4-year follow-up of root canal obturation using a calcium silicate-based sealer and a zinc oxide-eugenol sealer: A randomized clinical trial

AIM

This randomized clinical trial assessed the outcomes of nonsurgical root canal treatment (RCT), comparing a calcium silicate-based sealer (CSBS) with the single-cone technique (SC) with a zinc oxide-eugenol (ZOE) sealer and warm vertical compaction (WVC).

METHODOLOGY

Ninety-two single- and multi-rooted teeth were divided into two groups and treated using either the SC with BioRoot™ RCS (BIO) or WVC with Pulp Canal Sealer™ EWT (PCS). Teeth with apical periodontitis (AP) in both groups were further divided into BIOAP and PCSAP subgroups. Standardized instrumentation and disinfection protocols were followed. Periapical index (PAI) was recorded, and clinical and radiographic follow-ups were conducted at 1, 3, 6, 12, 24, and 48 months. Outcomes considered included success rate (under strict and loose criteria), extraction, length of filling, voids, and extrusion rate, as well as changes in PAI score from baseline. Outcome variables and prognostic factors were analysed using binary and multiple logistic regression at p < .05.

RESULTS

Sixty-seven teeth were included (recall rate, 73%). At 4-year follow-up, the overall success rates (BIO + PCS) were 89.6% by loose criteria and 83.3% by strict criteria. Subgroup success rates (BIOAP+PCSAP) were 88.5% by loose criteria and 80.4% by strict criteria. There were no significant differences between the groups in terms of success rate, extraction rate, length of filling, voids, or extrusion (p > .05). The pattern of PAI reduction was similar in both groups (p = .806).

CONCLUSION

Treatment using the SC-CSBS technique and the ZOE sealer with the WVC technique demonstrated a similar success rate.

Cold Ceramic for Repairing Root Perforations: A Case Report

Root perforation may happen pathologically or iatrogenically at any stage of endodontic treatment. Repairing a Perforation can be challenging and can negatively affect the prognosis of the treatment. The prognosis depends on various factors, including the size and site of the perforation, the presence of microorganisms, and the time lapse between injury and repair. One crucial factor is using a suitable material with favorable biocompatibility, moisture tolerance, and sealing abilities. Thus, choosing the suitable perforation sealing material can significantly affect the outcomes. Many materials have been suggested for perforation repair. However, searching for an ideal material continues, indicating the complicated nature of root perforations. In this study, three patients, two male and one female, received treatment for root perforation, each varying in the prognosis determinant factors. All cases were managed non-surgically with cold ceramic (CC) as the repairing material. After follow-up, they were clinically and radiographically examined, and all three cases revealed relatively complete healing of the tissues and no signs or symptoms of inflammation. The results obtained from the presented cases indicated CC's sealing ability, biocompatibility, moisture tolerance, and bone and periodontium regeneration, which are essential for successful perforation repair. The favorable healing of the perforation and the elimination of inflammation in every case, as well as the existing literature, support the use of CC as a suitable material for sealing perforations. However, additional clinical research is recommended to further understand CC's qualities and potential.

Effect of Manipulation Methods and Storage Environments on the Microstructural, Chemical, and Mechanical Properties of Calcium-Enriched Mixture Cement

This study aimed to evaluate the impact of different manipulation methods and storage environments on the microstructural, chemical, and mechanical properties of calcium-enriched mixture (CEM) cement. Four sample groups were examined, including nondried (ND-I) and dried (D-I) groups placed directly in an incubator, dried samples stored in phosphate-buffered saline (PBS) (D-P), and dried samples stored in distilled water (D-W). Various analyses, including Vickers microhardness, compressive strength, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDS) were conducted after incubating the samples for 7 days. The data were analyzed by Shapiro-Wilk, Levene, independent t, one-way ANOVA, and Tukey HSD tests. Key findings include the ND-I group exhibited a significantly longer setting time but the lowest microhardness and compressive strength. D-P showed the highest microhardness, while D-W displayed the highest compressive strength. FTIR analysis revealed vibration modes related to (PO4)3- ions and Si compounds in all groups, with dried groups showing more vibrations of (PO4)3- ions and OH groups, and D-P and D-W groups displayed vibration modes of (CO3)2- ions. XRD analysis indicated increased tri/dicalcium silicate reflections in CEM groups exposed to PBS or distilled water. D-I and D-W groups presented hexagonal or rectangular cubic and needle-like crystals, while D-P showed a homogeneous globular structure covered with fine crystals. The order of the weight percentage of major elemental constituents of D-P group was oxygen, calcium, phosphorus, zirconium, barium, carbon, silicon, and sulfur. Incremental placement, drying each increment, and exposing CEM to PBS/tissue fluids result in a faster set and more tolerant cement with a more uniform microstructure. The formation of hydroxyapatite can occur on the surface of the set cement.

Multi-modal Restorative Endodontic Management to Rehabilitate and Salvage a Tooth with External Cervical Resorption and Iatrogenic Over Enlarged Root Canal with Widened Apex

The presence of both a pathologic external cervical resorption (ECR) and an iatrogenic over-enlarged root canal with a widened apex can significantly compromise the structural integrity of a tooth. Furthermore, regular restorative-endodontic management of the involved tooth poses many procedural challenges and difficulties. However, a multi-modal approach involving nonsurgical and surgical procedures with the application of advances in endodontics can help to manage and salvage such a tooth. This article aims to report on a case of multi-modal management with the application of cone-beam computed tomography, micro-endodontics, bioactive and biomimetic materials, and monobloc effect to manage and structurally rehabilitate and reinforce a tooth affected by both ECR and over enlarged canal with a widened apex. This multi-modal approach was applied with nonsurgical and surgical treatments to restoratively and endodontically manage the affected tooth. Clinical and radiographic follow-up of the tooth was uneventful and showed satisfactory and favorable outcomes.

Regenerative Treatment of Mature Teeth with Pulp Necrosis and Apical Periodontitis Using Biodentine Compared with MTA: Randomized Controlled Clinical Trial

OBJECTIVE

The purpose of this randomized, controlled study was to evaluate the effectiveness of Biodentine compared with MTA used as a pulp space barrier in healing periapical lesions and regaining pulp sensitivity after regenerative treatment in mature single-canal permanent teeth with pulp necrosis and apical periodontitis.

METHODS

The study involved 36 patients with mature teeth with necrotic pulp and apical periodontitis. The patient underwent a regenerative treatment that utilized the blood clot technique. Teeth were randomly allocated to either the intervention, Biodentine, group (n=18) or the control, MTA, group (n=18). The healing of periapical lesions and tooth sensibility were evaluated throughout follow-up visits for up to 18 months.

RESULTS

The study analyzed 31 patients; two patients within the biodentine group and three in the MTA group were lost to follow-up. After 18 months, both groups showed effective healing of periradicular lesions; 21 out of 31 patients (67.7%) were healed, ten patients (32.3%) were healing, and no failure cases occurred. There were no significant differences between the groups (p=1.00). More than 70% (22 out of 31 patients) regained their sensibility in their teeth, and the groups had no statistically significant difference (p=0.703).

CONCLUSION

Regenerative treatment using blood clots with either MTA or Biodentine effectively resolved periapical lesions and regained the sensibility of mature teeth.

Evaluation of the Effect of Chitosan-Based Irrigation Solutions on the Bond Strength of Mineral Trioxide Aggregate to Bulk-Fill Composite

(1) Background: Bond strength between repair and restorative materials is crucial for endodontic success. This study assessed the effects of the following final irrigation solutions on the bond strength of mineral trioxide aggregate (MTA) to a bulk-fill composite: (1) 17% Ethylenediamine tetraacetic acid (EDTA); (2) 2% Chlorhexidine (CHX); (3) 0.2% chitosan; (4) 0.2% chitosan with 2% CHX; 5) 0.2% chitosan with AgNPs. (2) Methods: Sixty MTA samples were divided into six groups (n = 10) based on the final irrigation solution: 1. EDTA, 2. CHX, 3. Chitosan, 4. Chitosan-CHX, 5. Chitosan-AgNP, and 6. distilled water (control). After a 5-min solution exposure, each sample was restored with the bulk-fill composite, and the shear bond strength (SBS) was measured. Structural changes in MTA were analyzed using SEM and EDS, and failure modes were classified as adhesive, cohesive, or mixed. Data were analyzed by one-way ANOVA with Tamhane's T2 and Tukey's tests (α = 0.05). (3) Results: EDTA exhibited the lowest SBS (p < 0.001), while Chitosan-CHX showed the highest. SEM showed a spongy, void-rich surface in EDTA-treated MTA, with significant Ca depletion per EDS. Chitosan-CHX showed no structural change. Cohesive fractures within MTA were predominant. (4) Conclusions: EDTA significantly reduces SBS, while chitosan with CHX enhances bond strength.

Histological response of inflamed pulp to hydraulic calcium silicate cements in direct pulp capping: Systematic review of pulpitis models

This systematic review aimed to compare the histological response of inflamed pulpodentinal complex to the hydraulic calcium silicate cements in experimental animal models of pulpitis. Articles that evaluated the histological response of inflamed pulp to mineral trioxide aggregate (MTA) in comparison with other restorative materials were selected and analysed in detail. The risk of bias assessment was conducted using SYRCLE's RoB tool. The GRADEpro tool was used to determine the overall quality of evidence. Out of the 2947 retrieved articles from databases, five articles fulfilled the inclusion criteria. MTA induced significantly more hard tissue formation compared to calcium hydroxide. The use of pulp-capping material containing fluocinolone acetonide and ASP/PLGA-ASP/ACP/PLLA-PLGA composite membrane was comparable. This systematic review could not demonstrate enhanced efficiency of capping materials compared to MTA. Future well-conducted animal studies are warranted for demonstrating the hard tissue formation abilities of pulp-capping materials with convenient inflammatory conditions.

Outcomes of apexification in immature traumatised necrotic teeth and risk factors for premature tooth loss: A 20-year longitudinal study

BACKGROUND/AIM

To evaluate the long-term survival of immature traumatized incisors with pulp necrosis and apical periodontitis after endodontic treatment with two apexification techniques (calcium hydroxide apexification and MTA-apical plug) and to identify major factors affecting the survival of these teeth.

MATERIALS AND METHODS

Records of 2400 children and adolescents were screened for presence of traumatic dental injuries to immature incisors where endodontic treatment with the two apexification techniques was performed during January 2003 and December 2022, compared to a control group of mature teeth treated with conventional endodontic techniques. The studied variables were age; sex; apexification technique, presence of luxation and hard tissue injuries; preoperative root development stage (RDS), preoperative and postoperative periapical index (PAI), the time-point for tooth loss, and overall survival time in years. Kaplan-Meier estimates were used to graphically present the survival functions and Cox proportional hazard model to calculate hazard ratios (HR, 95% CI).

RESULTS

The median survival time was 10 years for calcium hydroxide apexification, 16.1 for MTA-apexification, for luxation injuries other than intrusions and avulsions 15.5 years, for intrusions 12.5 years and for avulsions 6.8 years. The variables with significant negative impact on tooth survival were calcium hydroxide apexification, avulsion and postoperative PAI 3-5. No significant relationships were found for the variables MTA apexification, concussion; subluxation; lateral luxation; extrusion, intrusion, hard tissue injuries, preoperative RDS and PAI scores and postoperative PAI 1-2. After adjustment, the risk for premature tooth loss was 13.5 times higher in calcium hydroxide apexification, approximately 2 to 4 times higher in PAI 3-5, and 5.6 times higher in avulsions.

CONCLUSIONS

Calcium hydroxide apexification, avulsion, and postoperative PAI 3-5 were identified as prognostic variables with significant negative impact on the risk for premature tooth loss.

Successful retreatment of a maxillary central incisor with a wide-open apex using MTA to fill the entire canal: 24-year follow-up

Managing teeth with open apices can be a challenging scenario for clinicians. This case report describes the 24-year follow-up of a maxillary central incisor that failed to develop after a traumatic injury resulting in a wide-open apex. A 10-year-old girl presented complaining of discomfort in her upper teeth. Tooth #9 had received a traumatic blow several years before and was discoloured with a resin composite restoration on the mesio-incisal edge. The tooth was painful to percussion and palpation. An inadequate root canal filling and incomplete root formation were observed on the initial periapical radiograph. Root canal retreatment was initiated, and the canal filled entirely with mineral trioxide aggregate (MTA) because of the extremely wide canal and open apex. The patient was asymptomatic at the 24-year follow-up with the cone beam computed tomography and periapical radiographs demonstrating the stability of the MTA.

Conservative Management of Horizontal Root Fracture: A Case Report

In cases where permanent teeth have closed apices and completely erupted roots, the probability of root fractures is increased due to the stable support given by the adjacent bone and periodontal tissues. Fractures have the potential to affect several dental structures, including the pulp, dentin, cementum, bone, and periodontal tissues. In cases of horizontal root fractures (HRF), the apical section typically maintains vitality; however, the present case presented an unusual apex necrosis. Given the patient's age and tooth stability, traditional apical surgery was deemed inappropriate. Instead, a conservative treatment approach was chosen to preserve the tooth. This case report details the management and a 2-year follow-up of a maxillary central incisor exhibiting a HRF and apical necrosis, successfully addressed through the application of Mineral Trioxide Aggregate (MTA) in the both apical and coronal segments. Using MTA prevented apical surgery in cases of apex necrosis accompanied by HRF.

Comparing the technical quality and clinical outcomes of root canal treatment on immature permanent incisors in children: a retrospective evaluation of three bioceramic plug materials

PURPOSE

To assess the technical quality and clinical outcomes of non-surgical endodontic treatment of immature permanent incisor teeth with three different bioceramic plug materials and highlight variables which may influence treatment and quality outcomes.

METHODS

This cross-sectional analysis forms part of a retrospective service evaluation of the technical quality and clinical outcome of orthograde root canal treatment carried out in the Paediatric Dentistry Department of Charles Clifford Dental Hospital (United Kingdom). Twenty-five cases were identified chronologically, using the electronic patient record system, for three bioceramic plug materials: Mineral Trioxide Aggregate (MTA), Biodentine, and TotalFill Putty. All radiographs were analysed using standard conditions. Intra- and inter-examiner agreement was calculated using Kappa and weighted Kappa tests. Data were collected using a data collection tool, entered into Microsoft Excel, and analysed using descriptive statistics, exploratory analysis with Chi-squared tests, and multivariable analyses (logistic regression).

RESULTS

At 12-month review, the success rate for each apexification material was MTA (84%), Biodentine (88%), and TotalFill Putty (92%). MTA had the highest frequency of post-operative coronal discolouration, with Biodentine most associated with apical extrusion. A number of variables and trends that affect the clinical outcome were identified, including the presence of pre-operative resorption, the number of operators involved in treatment, the number of appointments to complete treatment, as well as how non-use of local anaesthetic during apical plug placement had no adverse effect on technical quality or clinical outcome.

CONCLUSIONS

MTA, Biodentine, and TotalFill Putty are highly effective apexification materials which produce excellent clinical outcomes. As such, logistical and situational factors, such as continuity of care from operators with increased levels of experience, skill and ability, rather than material choice, may be more prognostic regarding the technical quality and clinical outcome of immature endodontic treatment. Further high-quality evidence is required.

Regenerative endodontic treatment and traumatic dental injuries

Pulp necrosis is the most common complication following dental trauma and is often associated with apical periodontitis. The management of these teeth is challenging in terms of large root canals, open apices, thin dentinal walls, and short roots. Over decades the conventional treatment for these teeth was calcium hydroxide apexification, a time-consuming procedure despite high success rates. Subsequently after the introduction of mineral trioxide aggregate and hydraulic calcium silicate materials single visit apical plug procedures became increasingly practiced with comparable success rates to the conventional apexification. The search continued afterward for a clinical procedure that may stimulate further root development and apical closure to avoid the long-term complication of root fracture after apexification. Regenerative procedures using stem cells derived from the apical papilla and blood clots as scaffolds were then introduced for the management of immature teeth, with variable protocols and success rates. This review will cover the evidence available and current position of regenerative endodontic procedures in traumatized immature teeth with apical periodontitis, in terms of clinical protocols, outcome, and potential prognostic factors.

Aluminum-Free Borosilicate Glass Functionalized Hydrogels for Enhanced Dental Tissue Regeneration

Hydrogels are promising scaffolds for tissue regeneration, and borosilicate glass particles have demonstrated potential in enhancing the biological behaviour of dental pulp cells. However, the specific morphological characteristics of dental lesions and the diverse requirements of dental tissues require biocompatible, bioactive, and shapeable scaffolds. This study aimed to evaluate the in vitro biological behaviour of human gingival fibroblasts (HGFs) in contact with an experimental aluminum-free borosilicate glass-functionalized hydrogel. Two types of experimental borosilicate glass particles were utilized, with Biodentine® particles serving as a reference material. The hydrogel, based on poly(L-lysine) dendrimers (DGL) with or without borosilicate particles, was analyzed using micro-computed tomography (µCT) and scanning electron microscopy (SEM) coupled with energy-dispersive X-ray spectroscopy (EDX). Cytocompatibility was assessed using Live/Dead™ staining, and cell colonization was evaluated via confocal imaging. Additionally, Alizarin red staining was performed to assess mineralization potential after 7 and 14 days. Results indicated that the incorporation of borosilicate particles did not alter hydrogel porosity, while EDX confirmed particle presence on the hydrogel surfaces. Furthermore, the borosilicate-functionalized hydrogels significantly enhanced cell proliferation, colonization, and the content of calcium deposits. These findings highlight the potential of these hydrogels for future clinical applications in dental tissue regeneration, pending further development.

Evaluating the Restoration of External Root Resorption Under Biomechanical Stress: A Finite Element Analysis

BACKGROUND

Root resorption is a complex problem in endodontic treatment that considerably affects the structural integrity of teeth. This study aims to assess the biomechanical efficacy of various restorative materials and approaches in treating external root resorption, emphasizing their capacity to improve stress resistance and guarantee long-term success.

METHODS

This research employed finite element analysis (FEA) to assess stress distribution in mandibular premolars with external root resorption. Eight models, demonstrating apical and mid-level resorption, were repaired using mineral trioxide aggregate (MTA), Biodentine, or a mixture of these materials with gutta-percha. In order to evaluate each technique's biomechanical performance, the models were exposed to both vertical and oblique stresses.

RESULTS

The findings demonstrated that complete canal obturation with Biodentine or MTA greatly lowered stress levels, with Biodentine exhibiting a marginal advantage. The hybrid approach utilizing gutta-percha produced elevated stress concentrations, especially under oblique loading conditions.

CONCLUSION

MTA and Biodentine are effective in enhancing resistance to biomechanical forces in teeth with external resorption. However, the combination of gutta-percha with these materials reduces resistance, especially under oblique forces. These findings highlight the importance of material selection in restoring resorbed teeth and improving clinical outcomes.

Postoperative pain after total pulpotomy and root canal treatment in mature molars according to the new and traditional classifications of pulpitis: a prospective, randomized controlled trial

BACKGROUND

The aim of this study was to compare postoperative pain following total pulpotomy (TP) and root canal treatment (RCT) in mature molar teeth with irreversible pulpitis. To compare the traditional pulpitis classification system with the Wolters system in evaluating postoperative pain.

METHODS

Eighty mandibular molars with irreversible pulpitis were included and classified according to the Wolters (moderate/severe pulpitis). The teeth were randomly assigned to two groups (RCT or TP). RCT was performed following standardized protocols. TP was performed to the level of the canal orifices, and hemostasis was achieved with 2.5% sodium hypochlorite. A 3 mm layer of MTA was placed as the pulpotomy material. The teeth were restored with glass ionomer cement followed by composite. Pain scores were recorded preoperatively and, at 6, 12, 24, 48, and 72 h and 7 days after the interventions. The data were statistically analyzed using the Mann-Whitney U test, the Friedman test, the Wilcoxon signed-rank test, and the Spearman's correlation test. The significance level was set at 0.05.

RESULTS

Sixty-four patients were analyzed at the one-week follow-up and all were diagnosed as irreversible pulpitis according to the AAE; 22 teeth were classified as moderate and 42 teeth were classified as severe pulpitis according to Wolters. There was no significant difference between TP and RCT in pain scores in moderate pulpitis patients (p > 0.05). There was a significant difference between TP and RCT at 24 and 72 h of severe pulpitis; higher pain scores were observed in the RCT (p < 0.05).

CONCLUSIONS

In patients with moderate pulpitis, the TP procedure allowed symptom relief more quickly than RCT. In patients with severe pulpitis, TP provided for significantly lower pain scores compared to RCT at both 24 and 72 h.

CLINICAL TRIAL REGISTRATION

The study was retrospectively registered with ClinicalTrials.gov (NCT05923619). Date of Registration: 06/16/23.

Intraradicular reinforcement of traumatized immature anterior teeth after MTA apexification

This review article describes the methods and clinical recommendations for reinforcing traumatized anterior immature teeth with pulp necrosis treated with mineral trioxide aggregate (MTA) apexification. Traumatic injury can cause pulp necrosis and incomplete root formation in immature teeth. MTA apexification is the treatment of choice for necrotic immature teeth, particularly during the middle or late stages of root development. MTA apexification has a high success rate; however, failures due to cervical or root fractures occasionally occur. The risk of fracture is higher in immature teeth with thin root dentin, particularly those with external root resorption. Furthermore, the loading force from any parafunctional habit also increases fracture risk. Therefore, intra-radicular reinforcement may be necessary after MTA apexification. In vitro, intraradicular restoration with a resin composite/core build-up material or a prefabricated fiber post demonstrated better root reinforcement than root canal obturation materials (i.e., gutta-percha and sealer). However, the root-reinforcement effect of MTA orthograde filling in the entire root canal remains unclear. In vivo, the survival of fractured teeth with intraradicular restorations (resin composite/core build-up material or prefabricated fiber posts) is extremely high. Moreover, the survival of teeth with gutta-percha/sealer obturation or MTA orthograde filling and restoration with resin composite extending into the cervical third of the root canal approximately 1-2 mm below the cemento-enamel junction is acceptably high. Based on this evidence, the remaining tooth/root structure and loading force should be carefully examined when considering intra-radicular reinforcement of immature anterior teeth treated with MTA apexification.

Quality of different obturation techniques to fill perforating internal root resorption: a micro-computed tomographic study

BACKGROUND

This study aimed to assess the quality of various obturation techniques to fill perforation caused by internal root resorption using Micro-computed Tomography.

METHODS

Cone-beam computed tomography images of a maxillary central incisor tooth with perforating internal resorptive defect were used to create a 3D printed model of the affected tooth. The replicas were divided into four groups based on the obturation technique used. The techniques included Group 1: a polydimethylsiloxane-based sealer (GuttaFlow-2) with gutta-percha. Group 2: same as Group 1 except for using a pre-mixed Bioceramic-based sealer (NeoSEALER Flo). Group 3: the defect was filled entirely using the NeoSealer Flo Bioceramic-based sealer. Group 4: the samples were obturated using the warm vertical compaction technique with a resin-based sealer (ADSeal). The resin models were then scanned a micro-computed scanner to evaluate the percentage of voids in each group.

RESULTS

The results showed that NeoSEALER Flo groups had significantly the highest volume of voids while GuttaFlow-2 and warm vertical compaction groups had the lowest void volume.

CONCLUSIONS

GuttaFlow-2 and warm vertical compaction techniques performed best in filling the internal resorptive defect.

Removal efficiency of a fast setting pozzalan-based bioactive cement: a micro CT study

AIM

The aim of this study was to evaluate the removal efficiency of PRMTA and ECMPremixed applied to the coronal third according to the RET by UI and to examine the effect of different solutions on material removal.

MATERIALS AND METHODS

40 permanent upper central teeth were used to simulate immature teeth. The samples were irrigated with 1.5% NaOCl and calcium hydroxide was placed. Samples were incubated in PBS. Then irrigation was done with 17% EDTA, the samples were randomly divided into 2 groups (n = 20):Group 1: PRMTA, Group 2: ECM Premixed. The materials were placed in the samples. Then the samples were scanned with micro-CT. Materials were removed by UI. Micro-CT scan of the samples was performed. Each material group was divided into 2 subgroups (n = 10): Group1 was MTAD, group2 was irrigated with 10% CA; then micro-CT was performed. Obtained images were positioned in DataViewer and analyzed with CTAn. The obtained data were statistically analyzed in IBM SPSS 25. The significance level was determined as 5%.

RESULTS

There was no significant difference between the initial volumes of the materials (p > 0.05). The amount of the remaining material after UI was significantly higher in the PRMTA (0.7471%) group compared to the ECM Premixed (0.0093%). There was no significant difference in terms of remaining material after irrigation with MTAD and CA in both groups (p > 0.05).

CONCLUSION

A great deal of the materials were removed by UI under the operation microscope. ECM Premixed was removed more effectively compared to the PRMTA. And, acidic solutions did not provide any additional benefit in material removal.

Treatment outcomes and prognostic factors of the apical barrier technique with premixed calcium silicate-based putty in necrotic permanent teeth with open apices: a retrospective cohort study with up to six years follow-up

OBJECTIVES

To evaluate treatment outcomes of the apical barrier technique with premixed calcium silicate-based putty for treating necrotic permanent teeth with open apices and to identify prognostic factors.

MATERIALS AND METHODS

Permanent teeth with necrotic pulps and open apices treated by the apical barrier technique with premixed calcium silicate-based putty, with a minimum follow-up of 12 months, were included. Treatment outcomes were based on clinical signs, symptoms, and radiographic evaluation. The treatment outcome was dichotomized into success or failure according to strict and loose criteria. The chi-square test (or Fisher's exact test) and multiple logistic regression analysis were used to evaluate possible prognostic factors associated with treatment outcomes.

RESULTS

Seventy-four teeth with a follow-up time of 12-72 months (mean, 25.74 ± 14.36 months) were included in the final evaluation. The success rate was 97.30% using the loose criteria and 66.22% using the strict criteria. Multiple logistic regression analysis indicated that the size of pre-operative periapical lesion (≥ 5 mm) (odds ratio [OR]: 18.96; P = 0.0153) and root canal underfilling (OR: 8.341; P = 0.0448) were significant predictors for treatment failure under the strict criteria.

CONCLUSION

The apical barrier technique with premixed calcium silicate-based putty is a highly successful procedure for treating necrotic permanent teeth with open apices after an observation period of up to 6 years. Treatment success under the strict criteria is primarily affected by the size of the pre-operative periapical lesion and the apical extent of root-filling.

CLINICAL RELEVANCE

Careful case selection and ensuring adequate root filling quality are essential to the successful outcome of the apical barrier technique with premixed calcium silicate-based putty.

Nanoparticulate bioceramic putty suppresses osteoclastogenesis and inflammatory bone loss in mice via inhibition of TRAF6-mediated signalling pathways: A laboratory investigation

AIM

This study aimed to determine the effects of iRoot BP Plus on receptor activator of nuclear factor-κB ligand (RANKL)-induced osteoclastogenesis in vitro and inflammation-mediated bone resorption in vivo and investigated the underlying molecular mechanisms.

METHODOLOGY

CCK-8 was performed to test cell viability in RANKL-induced RAW 264.7 cells and BMDMs in response to iRoot BP Plus. The effect of iRoot BP Plus on osteoclastogenesis was determined using TRAP staining and phalloidin staining, respectively. Pit formation assay was conducted to measure osteoclast resorptive capacity. Western blot and qPCR were performed to examine osteoclast-related proteins and gene expression, respectively. Western blot was also used to investigate the signalling pathways involved. For in vivo experiments, an LPS-induced mouse calvarial bone resorption model was established to analyse the effect of iRoot BP Plus on bone resorption (n = 6 per group). At 7 days, mouse calvaria were collected and prepared for histological analysis.

RESULTS

We identified that iRoot BP Plus extracts significantly attenuated RANKL-induced osteoclastogenesis, reduced sealing zone formation, restrained osteolytic capacity and decreased osteoclast-specific gene expression (p < .01). Mechanistically, iRoot BP Plus extracts reduced TRAF6 via proteasomal degradation, then suppressed the phosphorylation of mitogen-activated protein kinases (MAPKs), blocked the nuclear translocation of c-Fos and diminished nuclear factor-κB (NF-κB) p65 and NFATc1 accumulation. Consistent with the in vitro results, iRoot BP Plus extracts attenuated osteoclast activity thus protecting against inflammatory bone resorption in vivo (p < .05), which was accompanied by a suppression of TRAF6, c-Fos, NFATc1 and cathepsin K expression.

CONCLUSION

These findings provide valuable insights into the signalling mechanisms underlying nanoparticulate bioceramic putty-mediated bone homeostasis.

Bacterial sealing ability of calcium silicate-based sealer for endodontic surgery: an in-vitro study

BACKGROUND

Apical surgery with standard retrograde maneuvers may be challenging in certain cases. Simplifying apical surgery to reduce operating time and streamline retrograde manipulation is an emerging need in clinical endodontics.

AIM OF THE STUDY

The aim of the study was to compare the bacterial sealing ability of a calcium silicate-based sealer with the single cone technique combined with root end resection only, and calcium silicate-based sealer as a retrograde filling versus MTA retrofilling, and to analyze bacterial viability using confocal laser scanning microscope (CLSM).

MATERIALS AND METHODS

In this in vitro experimental study, 50 extracted human maxillary incisor teeth were instrumented and randomly divided into five groups: three experimental groups, a positive control group, and a negative control group (n = 10/group). In the experimental groups, the roots were obturated using the single cone technique (SCT) and a calcium silicate-based sealer. In group 1, the roots were resected 3 mm from the apex with no further retrograde preparation or filling. In groups 2 and 3, the roots were resected, retroprepared, and retrofilled with either a calcium silicate-based sealer or MTA, respectively. Group 4 (positive control) was filled with a single gutta-percha cone without any sealer. In group 5 (negative control), the canals were left empty, and the roots were sealed with wax and nail varnish. A bacterial leakage model using Enterococcus faecalis was employed to assess the sealing ability over a 30-day period, checking for turbidity and analyzing colony forming units (CFUs) per milliliter. Five specimens from each group were examined using CLSM for bacterial viability. Data for the bacterial sealing ability were statistically analyzed using chi-squared and Kruskal-Wallis tests.

RESULTS

The three experimental groups did not show significant differences in terms of bacterial leakage, or bacterial counts (CFUs) (P > 0.05). However, significant differences were observed when comparing the experimental groups to the positive control group. Notably, the calcium silicate-based sealer, when used as a retrofilling, yielded the best sealing ability. CLSM imaging revealed viable bacterial penetration in all the positive control group specimens while for the experimental groups, dead bacteria was the prominent feature seen.

CONCLUSION

Within the limitations of this study, it could be concluded that the bacterial sealing ability of calcium silicate-based sealer with the single cone technique combined with root end resection only and calcium silicate-based sealer as a retrograde filling were comparable with MTA retrofilling during endodontic surgical procedures.

Pulp regeneration treatment using different bioactive materials in permanent teeth of pediatric subjects

Background and Objectives

The present systematic review aims to assess the success rate of the pulp regeneration treatment, according to the American Association of Endodontists (AAE) criteria, using different bioactive materials in permanent teeth of pediatric subjects (6-17 years of age).

Materials and Methods

The study protocol was registered on PROSPERO and adhered to the Preferred Reporting Items for Systematic Reviews and Meta-analyses statement. The question formulation was accomplished using the PICO model, and an electronic search was carried out on Scopus, MEDLINE/PubMed, Web of Science, and Cochrane databases till April 1, 2023. A total of 30 studies were established to fulfill the inclusion criteria of this systematic review.

Results

A total of 273 teeth have been treated with pulp regeneration treatment. By comparing different biomaterials and the success criteria defined by the AAE, the material associated with a higher success rate was found to be the white mineral trioxide aggregate. However, the overall success rate of pulp regeneration treatment was reported for 248 out of 273 teeth (91.20%).

Conclusions

Data obtained support the potential that regenerative endodontics aids in continuing root development in permanent immature teeth. Further studies are needed for a more extensive evaluation of the use of different biomaterials and the success rate in regenerative endodontics.

Strontium-Containing Piezoelectric Biofilm Promotes Dentin Tissue Regeneration

It remains an obstacle to induce the regeneration of hard dentin tissue in clinical settings. To overcome this, a P(VDF-TrFE) piezoelectric film with 2 wt% SrCl2 addition is designed. The biofilm shows a high flexibility, a harmonious biocompatibility, and a large piezoelectric d33 coefficient of 14 pC N-1, all contributing to building an electric microenvironment that favor the recruitment of dental pulp stem cells (DPSCs) and their differentiation into odontoblasts during normal chewing, speaking, etc. On the other hand, the strontium ions can be gradually released from the film, thus promoting DPSC odonto-differentiation. In vivo experiments also demonstrate that the film induces the release of dentin minerals and regeneration of dentin tissue. In the large animal dentin defect models, this piezoelectric film induces in situ dentin tissue formation effectively over a period of three months. This study illustrates a therapeutic potential of the piezoelectric film to improve dentin tissue repair in clinical settings.

Application of Nanomaterials in Endodontics

Recent advancements in nanotechnology have introduced a myriad of potential applications in dentistry, with nanomaterials playing an increasing role in endodontics. These nanomaterials exhibit distinctive mechanical and chemical properties, rendering them suitable for various dental applications in endodontics, including obturating materials, sealers, retro-filling agents, and root-repair materials. Certain nanomaterials demonstrate versatile functionalities in endodontics, such as antimicrobial properties that bolster the eradication of bacteria within root canals during endodontic procedures. Moreover, they offer promise in drug delivery, facilitating targeted and controlled release of therapeutic agents to enhance tissue regeneration and repair, which can be used for endodontic tissue repair or regeneration. This review outlines the diverse applications of nanomaterials in endodontics, encompassing endodontic medicaments, irrigants, obturating materials, sealers, retro-filling agents, root-repair materials, as well as pulpal repair and regeneration. The integration of nanomaterials into endodontics stands poised to revolutionize treatment methodologies, presenting substantial potential advancements in the field. Our review aims to provide guidance for the effective translation of nanotechnologies into endodontic practice, serving as an invaluable resource for researchers, clinicians, and professionals in the fields of materials science and dentistry.

Reprint of: The Effect of Mineral Trioxide Aggregate Obturation Levels on the Outcome of Endodontic Retreatment: An Observational Study

INTRODUCTION

No clinical studies have examined the effect of mineral trioxide aggregate (MTA) obturation levels on the outcome of endodontic retreatment. This retrospective study examined treatment outcomes in three cohorts that compared overfilling, flush filling, and underfilling after orthograde retreatment using MTA.

METHODS

Two hundred fifty patients with 264 teeth diagnosed with previously treated root canals and apical periodontitis retreated in a private endodontic practice were included. All teeth received MTA obturation and the extent of the final filling level was measured in relation to the major apical foramen. After 6-month follow-ups, all nonhealing cases were treated surgically. After 24- to 72-month reviews, the effect of preoperative lesion size and the degree of MTA obturation level were assessed. Multiple linear regression and time-to-event analysis using Stata 17 software (StataCorp LLC, College Station, TX) were used to evaluate the data.

RESULTS

Within the three cohorts, 99 out of 108 overfilled teeth (91.7%), 90 out of 103 flush fills (87.4%), and 10 out of 53 underfilled teeth (18.9%) healed and were successfully retreated without surgery at 48-months. When surgical outcomes were included, the combined healed proportion was 93.2%. Preoperative lesion size was found to be an important predictor for retreatment nonhealing. A 1-mm increase in lesion size at baseline resulted in an estimated 11% (95% CI 1.04, 1.18)-38% (95% CI 1.22, 1.58) increase in the risk of surgery. Compared to overfilling and flush filling, underfilling was associated with an approximately three-fold increase in requiring surgery and characterized by delayed healing.

CONCLUSION

MTA obturation is a viable retreatment option for teeth with nonhealing endodontic treatment. MTA overfills or flush fillings do not adversely affect healing outcomes. However, MTA underfilling increases the chances for nonhealing and surgical intervention.

Cell Biological and Antibacterial Evaluation of a New Approach to Zirconia Implant Surfaces Modified with MTA

Peri-implantitis continues to be one of the major reasons for implant failure. We propose a new approach to the incorporation of MTA into zirconia implant surfaces with Nd:YAG laser and investigate the biological and the microbiological responses of peri-implant cells. Discs of zirconia stabilized with yttria and titanium were produced according to the following four study groups: Nd:YAG laser-textured zirconia coated with MTA (Zr MTA), Nd:YAG laser-textured zirconia (Zr textured), polished zirconia discs, and polished titanium discs (Zr and Ti). Surface roughness was evaluated by contact profilometry. Human osteoblasts (hFOB), gingival fibroblasts (HGF hTERT) and S. oralis were cultured on discs. Cell adhesion and morphology, cell differentiation markers and bacterial growth were evaluated. Zr textured roughness was significantly higher than all other groups. SEM images reveal cellular adhesion at 1 day in all samples in both cell lines. Osteoblasts viability was lower in the Zr MTA group, unlike fibroblasts viability, which was shown to be higher in the Zr MTA group compared with the Zr textured group at 3 and 7 days. Osteocalcin and IL-8 secretion by osteoblasts were higher in Zr MTA. The Zr textured group showed higher IL-8 values released by fibroblasts. No differences in S. oralis CFUs were observed between groups. The present study suggests that zirconia implant surfaces coated with MTA induced fibroblast proliferation and osteoblast differentiation; however, they did not present antibacterial properties.

MTA as modulator of periapical tissue healing in rat molar: A histological study

Background

Periapical surgery has been suggested as a treatment option for teeth with periapical lesions when those lesions continue despite receiving root canal therapy. Since sealing the apical region is the operation's primary goal, the choice of the root-end filling material affects how the surgery turns out. The retrofilling materials Zinc Oxide Eugenol (ZOE) and Mineral trioxide aggregate (MTA) are both known to have antibacterial characteristics. The purpose of this study is to determine how MTA affects as a Modulator of Periapical Tissue Healing through histological examination in Rat Molar.

Methods

A dental fissure bur measuring 0.7 mm is used to remove the buccal root apex from the buccal alveolar bone's surface, creating the cavity. One of the following is placed within each cavity: Group 1: MTA, Group 2: ZOE. For each material series, six samples were used. We classified the healing outcomes for each MTA and ZOE retrograde filling material into three groups based on histological analysis: the amount of newly generated bone, the number of fibroblasts, and the infiltration of neutrophils into the surgical site.

Results

On the 6th day of examination, fibroblasts were seen in the area around the wound. A significant inflammatory response, including neutrophil infiltration, was seen around the ZOE after retrograde filling. On the 16th day, the new alveolar bone structure showed a slight increase. After filling the MTA on the 6th day of examination, the immediate inflammatory response was insignificant. Neutrophils were observed to enter the region surrounding the retrofilled MTA, and a small number of osteoclasts were observed to be resorbing bone. Around the wound site, fibroblasts can also be detected. On the 16th day, unlike ZOE, a lot of new bone grows close to this material.

Conclusion

MTA has the ability to modulate periapical healing in rat molar.

The flow behavior and sealing ability of calcium silicate root canal cement containing dimethyl sulfoxide: An in vitro study

INTRODUCTION

To develop a calcium silicate (CaSi)-based cement containing dimethyl sulfoxide (DMSO) and cement deliver device for new root canal filling technique, and to assess the flow behavior, leakage, and root canal filling quality of CaSi containing DMSO.

METHODS

CaSi containing DMSO (CSC-DMSO) and CaSi containing PEG (CSC-PEG) were prepared, and the flow characteristics of both cements were compared in gypsum and resin channels using a high-speed camera. Eight root canals were obturated by CSC-DMSO or CSC-PEG using a cement delivery device, and root canal filling quality was assessed in terms of filling length using periapical radiographs. The filling length was evaluated by 'apico-coronal extension,' measuring length in reference to apical constriction. Microleakage was measured for thirty human molars that were randomly filled with CSC-DMSO, CSC-PEG, or gutta-percha and AH plus. Preliminary obturation of CSC-DMSO with cement delivery device in human teeth was analyzed in terms of filling length and void, using periapical radiographs. Statistical analysis was performed with the Kruskal Wallis test for simulated root canal fillings and one-way ANOVA for leakage test.

RESULTS

The flow speed of CSC-DMSO reduced in gypsum channels compared to resin channels, but CSC-PEG did not exhibit significant differences in the channels. The median absolute value of apico-coronal extension was significantly lower in CSC-DMSO compared to CSC-PEG (p < 0.05). Microleakage did not statistically differ between the groups (p > 0.05). In the preliminary obturation, the mean apico-coronal extension of CSC-DMSO was -0.297 ± 0.724 mm, while CSC-PEG was not feasible due to excess apical extrusions.

CONCLUSIONS

CSC-DMSO could be considered as an alternative filling material for root canal obturation.

In vitro and in vivo evaluation of iRoot BP Plus as a coronal sealing material for regenerative endodontic procedures

OBJECTIVES

To investigate in vitro effects of a nanoparticle bioceramic material, iRoot BP Plus, on stem cells from apical papilla (SCAP) and in vivo capacity to induce pulp-dentin complex formation.

MATERIALS AND METHODS

The sealing ability of iRoot BP Plus was measured via scanning electron microscopy (SEM). SCAP were isolated and treated in vitro by iRoot BP Plus conditioned medium, with mineral trioxide aggregate (MTA) conditioned medium and regular medium used as controls, respectively. Cell proliferation was assessed by BrdU labeling and MTT assay and cell migration was evaluated with wound healing and transwell assays. Osteo/odontogenic potential was evaluated by Alizarin red S staining and qPCR. Pulp-dentin complex formation in vivo was assessed by a tooth slice subcutaneous implantation model.

RESULTS

iRoot BP Plus was more tightly bonded with the dentin. There was no difference in SCAP proliferation between iRoot BP Plus and control groups (P > 0.05). iRoot BP Plus had a greater capacity to elevated cell migration (P < 0.05) and osteo/odontogenic marker expression and mineralization nodule formation of SCAP compared with MTA groups (P < 0.05). Furthermore, the new continuous dentine layer and pulp-like tissue was observed in the iRoot BP Plus group in vivo.

CONCLUSIONS

iRoot BP Plus showed excellent sealing ability, promoted the migration and osteo/odontogenesis of SCAP and induced pulp-dentin complex formation without affecting the cell proliferation, which indicated iRoot BP Plus was a promising coronal sealing material in REPs.

CLINICAL RELEVANCE

The coronal sealing materials play crucial roles for the outcomes of REPs. This study showed that iRoot BP Plus has good coronal sealing and promote pulp-dentin complex formation compared with MTA, providing experimental evidences for the clinical application of iRoot BP Plus as a promising coronal seal material in REPs.

Postoperative pain of single-visit endodontic treatment with gutta-percha versus MTA filling: a randomized superiority trial

BACKGROUND

Postoperative pain has remained a challenge for clinicians. This randomized superiority trial compared the levels of postoperative pain following the use of gutta-percha (GP) and sealer or mineral trioxide aggregate (MTA) as root canal filling materials in teeth with asymptomatic apical periodontitis.

METHODS

A total of 119 patients were initially evaluated in this two-arm, parallel-group, single-blind, superiority randomized trial. The inclusion criteria were participants aged 18-65 years with single-canal premolars diagnosed with asymptomatic apical periodontitis. The participants were finally divided into two groups using the permuted block randomization method. In the GP group (N = 46), the cleaned and shaped root canals were filled with gutta-percha and AH Plus sealer, while in the MTA group (N = 48), the cleaned and shaped root canals were filled with an MTA apical filling and a coronal gutta-percha and sealer. Patient pain level was measured 6, 12, 24, 48, and 72 h postoperatively using a 10-point visual analog scale (VAS). The data were analyzed by the chi-square, independent t, Friedman, and Mann-Whitney U tests.

RESULTS

The mean of VAS scores decreased significantly over time in both groups (P < 0.001). The mean VAS scores were significantly lower in the MTA filling group than in the other group (P < 0.05). Female patients reported higher VAS scores at 6- and 12-hour periods in both groups (P < 0.05).

CONCLUSION

MTA as a root canal filling material might be a valuable option for clinicians due to its low postoperative pain.

TRIAL REGISTRATION

The trial protocol was registered at the Registry of Clinical Trials (IRCT20191104045331N1).

Clinical management of external cervical resorption: A systematic review

This review investigated whether any therapeutic options influenced the outcome of treatment for teeth with external cervical resorption. Out of 870 articles identified by an electronic search, 60 clinical case reports and six case series were included. No randomised clinical trials were found. Risk of bias was assessed using Joanna Briggs Institute's tools. External surgical intervention was the preferred method of accessing the lesions. Removal of resorptive tissue was most often achieved mechanically. Bioactive endodontic cements were the preferred materials for restoring teeth. The outcome measures were based on clinical and radiographic parameters. Of the cases included in the review, no specific treatment approach had a superior outcome in relation to Heithersay's classification. Furthermore, due to the absence of randomised clinical trials, and the low level of evidence associated with case reports/case series, it was not possible to define the optimum clinical treatment for external cervical resorption.

3D finite element analysis of stress distribution as a result of oblique and horizontal forces after regenerative endodontic treatment part II: comparison of material thickness

AIM

This study aimed to evaluate the stress distribution caused by secondary trauma forces after regenerative endodontic treatment (RET) using different thicknesses of coronary barrier material with three-dimensional finite element analysis(FEA).

METHOD

A control model was created using the tomography image of the immature maxillary central tooth with computer software.Study models were created with the modulus of elasticity and Poisson's ratio of the materials used in RET.Enamel, dentin, cementum, periodontal ligament, cortical, and cancellous bone were modeled. Coronary barrier materials were applied in 3 mm and 5 mm thicknesses (Model 1: control model, model 2:3 mm/Calcium Enriched Mixture(CEM), model 3:3 mm/Mineral Trioxide Aggregate(MTA), model 4:3 mm/Biodentin, model 5:5 mm/CEM, model 6:5 mm/MTA, model 7:5 mm/Biodentin). For the trauma force simulation, 300 N force in the horizontal direction was applied to the buccal surface of the tooth in the first scenario. For the second scenario, maximum bite force simulation, a force of 240 N in the oblique direction was applied to the palatal surface of the tooth. FEA was performed with Algor Fempro. The resulting stresses were recorded as Von Mises, maximum, and minimum principal stresses.

RESULTS

Lower stress values were obtained in 5 mm models compared to 3 mm models. However, the difference between them was insignificant. Lower stress values were obtained in all RET models compared to the control model. The lowest stress values in dental tissues and bone tissue were obtained in the CEM models.

CONCLUSION

This is the first study in which the stress caused by different thicknesses of CEM on dental tissues was evaluated with FEA. RET strengthens immature teeth biomechanically. CEM and Biodentin are more successful materials in stress distribution than MTA. Considering the cost of treatment, 3 mm material thickness is ideal for RET since there is no significant difference between the stress values resulting from the use of 5 mm and 3 mm coronary barrier material.

Synergistic effect of ion-releasing fillers on the remineralization and mechanical properties of resin-dentin bonding interfaces

In modern restorative dentistry, adhesive resin materials are vital for achieving minimally invasive, esthetic, and tooth-preserving restorations. However, exposed collagen fibers are found in the hybrid layer of the resin-dentin bonding interface due to incomplete resin penetration. As a result, the hybrid layer is susceptible to attack by internal and external factors such as hydrolysis and enzymatic degradation, and the durability of dentin bonding remains limited. Therefore, efforts have been made to improve the stability of the resin-dentin interface and achieve long-term clinical success. New ion-releasing adhesive resin materials are synthesized by introducing remineralizing ions such as calcium and phosphorus, which continuously release mineral ions into the bonding interface in resin-bonded restorations to achieve dentin biomimetic remineralization and improve bond durability. As an adhesive resin material capable of biomimetic mineralization, maintaining excellent bond strength and restoring the mechanical properties of demineralized dentin is the key to its function. This paper reviews whether ion-releasing dental adhesive materials can maintain the mechanical properties of the resin-dentin bonding interface by supplementing the various active ingredients required for dentin remineralization from three aspects: phosphate, silicate, and bioactive glass.

Sol-Gel Technologies to Obtain Advanced Bioceramics for Dental Therapeutics

The aim of this work is to review the application of bioceramic materials in the context of current regenerative dentistry therapies, focusing on the latest advances in the synthesis of advanced materials using the sol-gel methodology. Chemical synthesis, processing and therapeutic possibilities are discussed in a structured way, according to the three main types of ceramic materials used in regenerative dentistry: bioactive glasses and glass ceramics, calcium phosphates and calcium silicates. The morphology and chemical composition of these bioceramics play a crucial role in their biological properties and effectiveness in dental therapeutics. The goal is to understand their chemical, surface, mechanical and biological properties better and develop strategies to control their pore structure, shape, size and compositions. Over the past decades, bioceramic materials have provided excellent results in a wide variety of clinical applications related to hard tissue repair and regeneration. Characteristics, such as their similarity to the chemical composition of the mineral phase of bones and teeth, as well as the possibilities offered by the advances in nanotechnology, are driving the development of new biomimetic materials that are required in regenerative dentistry. The sol-gel technique is a method for producing synthetic bioceramics with high purity and homogeneity at the molecular scale and to control the surfaces, interfaces and porosity at the nanometric scale. The intrinsic nanoporosity of materials produced by the sol-gel technique correlates with the high specific surface area, reactivity and bioactivity of advanced bioceramics.

Full Pulpotomy as a Treatment for Irreversible Pulpitis in Permanent Teeth: A Systematic Review of the Literature Based on Case Reports

The objective of this systematic review was to evaluate the current evidence of case reports where the treatment for permanent teeth with a diagnosis of irreversible pulpitis was a full pulpotomy. This study was carried out by two reviewers following the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. A systematic electronic search was carried out in the PubMed, Google Scholar, and Scopus databases until the year 2022 to find articles in English where the treatment for irreversible pulpitis in permanent teeth was a full pulpotomy. Literature reviews, in vitro or animal studies, abstracts, and unpublished data were excluded. The intervention, control, and outcome parameters were selected following the "Population, Interventions, Control, and Outcome" (PICO) guidelines. A total of 636 articles were found, and 14 articles were selected to be included in this review. The selected articles describe cases of full pulpotomies in mature permanent teeth with a diagnosis of irreversible pulpitis with a total of 34 (100%) successful cases, where 18 were men and 16 were women, with an average age of 19.20 ± 10.59 years and an average follow-up of 35.82 ± 26.39 months, with 12 months being the minimum follow-up time. The material used most frequently for obturation of the full pulpotomy was mineral trioxide aggregate in 16 cases (47.06%). Within the limitations of this review, full pulpotomy presents a high success rate regardless of the tooth, age, or sex as a treatment for teeth diagnosed with irreversible pulpitis.

Physicochemical, mechanical and biological properties of nano-calcium silicate-based cements: a systematic review

This systematic review evaluated the effects of nano-sized cement particles on the properties of calcium silicate-based cements (CSCs). Using defined keywords, a literature search was conducted to identify studies that investigated properties of nano-calcium silicate-based cements (NCSCs). A total of 17 studies fulfilled the inclusion criteria. Results indicated that NCSC formulations have favourable physical (setting time, pH and solubility), mechanical (push out bond strength, compressive strength and indentation hardness) and biological (bone regeneration and foreign body reaction) properties compared with commonly used CSCs. However, the characterization and verification for the nano-particle size of NCSCs were deficient in some studies. Furthermore, the nanosizing was not limited to the cement particles and a number of additives were present. In conclusion, the evidence available for the properties of CSC particles in the nano-range is deficient-such properties could be a result of additives which may have enhanced the properties of the material.

Effect of incorporation of nano-graphene oxide on physicochemical, mechanical, and biological properties of tricalcium silicate cement

OBJECTIVE

Evaluation of setting time, compressive strength, pH, calcium ion release, and antibacterial activity of mineral trioxide aggregate (MTA) after modification with three different concentrations of nano-graphene oxide (GO) powder compared to unmodified Biodentine as a commercial control.

METHODS

GO powder, unhydrated and hydrated cements were characterized using Environmental Scanning Electron Microscope (ESEM) with Energy Dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), Raman Spectroscopy, and Fourier Transform Infrared spectroscopy (FTIR). GO was also analyzed using Scanning Transmission Electron Microscope (STEM) to determine average lateral dimensions. Specimens were prepared and grouped according to the concentration of GO added to Rootdent MTA (control, 1, 3, and 5 wt%) and the material used (MTA and unmodified Biodentine) into five groups. Setting time was evaluated using Gillmore penetrometer (n = 5). Compressive strength was evaluated using universal testing machine (n = 7). pH and calcium ion release were assessed using pH meter and Induced Coupled Plasma-Optical Emission Spectroscopy (ICP-OES) at 1, 7, 14, and 28 days (n = 7). Antibacterial activity was evaluated against Streptococcus mutans using direct contact test (n = 7). One-way and repeated measures ANOVA followed by Tukey's post hoc test were used for data analysis with significance level set at p ≤ 0.05.

RESULTS

Addition of GO to MTA reduced both initial and final setting time. GO modified MTA groups and unmodified Biodentine showed significantly increased calcium ion release at 14 and 28 days. All cements showed alkaline pH of the storage media at all tested time intervals. 1 wt% GO recorded the highest compressive strength values in MTA modified groups. The increased concentration of GO from 1 to 5 wt% successively increased antibacterial activity of MTA, with Biodentine showing the lowest significant value.

CONCLUSION

Addition of 1 wt% GO can significantly improve the tested properties of tricalcium silicate-based cements without compromising their compressive strength.

CLINICAL SIGNIFICANCE

GO is a promising modification for tricalcium silicate cements to improve setting time, compressive strength, and antibacterial activity to provide a variety of materials for different clinical situations. This in turn can reduce the risk of reinfection and allow placement of the final restoration in a single visit.

Effectiveness of root resection techniques compared with root canal retreatment or apical surgery for the treatment of apical periodontitis and tooth survival: A systematic review

BACKGROUND

To manage apical periodontitis in root filled maxillary and mandibular molars, root resection techniques may be employed to avoid the loss of the tooth.

OBJECTIVES

The objectives of the study were to systematically analyse the effectiveness of root resection techniques (root resection/crown resection/root amputation) for the management of apical periodontitis with non-surgical root canal retreatment or apical surgery by the evaluation of clinical and patient-related outcomes (PROMS), in human experimental studies and longitudinal studies.

METHODS

An electronic literature search in PubMed, MEDLINE via OVID interface, EMBASE and Cochrane Central, supplemented by a manual hand search of the grey literature, was performed up to 25th September 2021. Randomized controlled trials, comparative clinical trials and observational studies reporting on the outcome (tooth survival and patient-reported outcome measures with a minimum follow-up of 1 year) of root resection techniques for treating apical periodontitis were identified. The risk of bias was evaluated using the Newcastle-Ottawa scale.

RESULTS

From a total of 2098 reports, 36 were considered for further screening. Three retrospective studies, published between 2018 and 2020, were included in this systematic review. A high heterogeneity in terms of protocols, study design and the reported outcomes were observed. The risk of bias was scored as low to moderate. These three studies consisted of data from 305 resected teeth, from 254 patients, with a follow-up period of 1-16.8 years. Overall, 151 teeth were extracted during the follow-up period. In these studies, root resection treatment was carried out on 42 teeth exclusively for endodontic reasons. One of these studies reported 12 out of 23 teeth lost at follow-up. None of the studies reported on PROMS.

DISCUSSION

Although root resection techniques may be used for treating teeth with apical periodontitis, the data are limited. Furthermore, the studies are very heterogeneous and associated with high risk of bias.

CONCLUSIONS

Given the current level of available evidence, it is not possible to recommend, or dismiss, root resection techniques for managing apical periodontitis.

REGISTRATION

PROSPERO database (CRD42021260306).