Pulp Space Research Articles

Antimicrobial Efficacy of a Novel Herbal Endodontic Irrigant Against Enterococcus Faecalis in Root Canals of Permanent Teeth: An in Vitro Study

Background: A successful endodontic treatment is aimed at the sterilization of the entire pulp space. The use of extracts from Rhamnus prinoides as a novel irrigating material for root canal has not been studied . Hence, the antimicrobial efficacy of the alcoholic extract of Rhamnus prinoides as an irrigation material against E. faecalis was evaluated in comparison with the 2.5% sodium hypochlorite (NaOCL) solution used for root canals of permanent teeth. Methods: A total of 30 single-rooted human permanent teeth were thoroughly cleaned, shaped, and disinfected. Then, each tooth was subjected to a two-week infection with Enterococcus faecalis at 37 °C . Afterward, the samples were divided into three groups (10 teeth per group): 0.9% normal saline, 2.5% sodium hypochlorite, and 250 µg/ml Rhamnus prinoides. Paper points were used before and after irrigation to collect samples. Bacterial growth was evaluated after 24 h. Bacterial colonies were counted. The data were examined statistically via one-way analysis of variance, Dunnett’s T3 post hoc test, and Shapiro–Wilk test. The level of significance was set at p<0.05. Results: The 2.5% sodium hypochlorite and 250 µg/ml Rhamnus prinoides demonstrated higher effectiveness against biofilm of Enterococcus faecalis than normal saline (p<0.05). The percentage of antibacterial effectiveness were 94.094 ±3.342, 93.685 ±5.280, and 25.603 ±3.912. Conclusions: Rhamnus prinoides, when used as root canal irrigant solution, was effective the sodium hypochlorite against the E. faecalis biofilm.

Breakthrough in the Development of Endodontic Irrigants.

The three main components of endodontic success are three-dimensional obturation, pulp space sterilization, and biomechanical preparation. Instrumentation techniques are insufficient to accomplish complete disinfection of the pulp space. It is essential to use additional tools, such as endodontic irrigants. This review article aims to provide a general overview of the different root canal irrigants and their clinical uses. Endodontic treatment focuses more on removing infectious material from the root canal system to facilitate the healing of an existing periapical lesion or to prevent the periradicular tissues from being infected. It is important to note that instrumentation alone can reach every part of the root canal wall. Therefore, the irrigation procedure is a crucial aspect of endodontic therapy. Irrigation requires the application of various irrigants, like sodium and chlorhexidine, to get rid of debris, bacteria, and tissue leftovers. The accomplishment of root canal treatments counts heavily on the thoroughness of irrigation, contributing to optimal canal shaping and disinfection. Modern root canal irrigation systems incorporate syringes, needles, and advanced delivery mechanisms, including sonic and ultrasonic devices. These inventions aim to enhance the mechanical action of irrigants, reaching intricate canal anatomy more efficiently. Understanding the dynamics of root canal irrigation and staying abreast of technological advancements are essential for clinicians to achieve improved treatment outcomes in endodontic procedures.

Efficacy of different irrigation techniques in removal of N-acetyl cysteine as an intracanal medicament- An study

Intra canalmedicament must be completely removed from the pulp space for better penetration of sealers. Various methods of irrigant delivery are used for removal of medicament from root canals. Removal of N-acetyl cysteine when used as an intracanal medicament hasn't been studied yet.To compare efficacy of different irrigation techniques, ultrasonic, sonic, navi tips, side vented needles in removal of N-acetyl cysteine as an intracanal medicament- an study Fifty-two maxillary anterior teeth were decoronated and standardized to a root length of 13 mm. Root canals were prepared with Protaper Universal rotary system. N-acetyl cysteine paste was placed in root canals with lentulospiral and kept in an incubator for 7 days. Then four groups (n=13) were established according to the removal technique- Group 1- Passive ultrasonic irrigation, Group 2- Sonic irrigation, Group 3- Manual irrigation with NaviTip, Group 4- Manual irrigation with side vented needles. Each tip was placed 2 mm short of working length and irrigation was done using 5.25% sodium hypochlorite. Final irrigation was done, then roots were split buccolingually and evaluated for residual medicament under stereomicroscope at 24x magnification. Done using Kruskal-Wallis and Mann-Whitney tests (P ≤ 0.05). In coronal and middle third, there was significant difference in removal of medicament by Group 1- Passive ultrasonic irrigation compared to other techniques, whereas, in apical third Group 2- Sonic irrigation showed better result. Group 3-Manual irrigation with NaviTip and Group 4- Manual irrigation with side- vented needles was significantly less effective than other techniques.Use of irrigants with activation devices like ultrasonic and sonic revealed improved removal of N- acetyl cysteine intracanal medicament.

How do different intraoral scanners and milling machines affect the fit and fatigue behavior of lithium disilicate and resin composite endocrowns?

The aim of this in vitro study was to evaluate the effect of the combinations of two different intraoral scanners (IOS), two milling machines, and two restorative materials on the marginal/internal fit and fatigue behavior of endocrowns produced by CAD-CAM. Eight groups (n= 10) were considered through the combination of TRIOS 3 (TR) or Primescan (PS) IOS; 4-axes (CR; CEREC MC XL) or 5-axes (PM; PrograMill PM7) milling machines; and lithium disilicate (LD; IPS e.max CAD) or resin composite (RC; Tetric CAD) restorative materials. Specific surface treatments were applied to each material, and the bonding to its corresponding Endocrown-shaped fiberglass-reinforced epoxy resin preparations was performed (Variolink Esthetic DC). Computed microtomography (μCT) was performed to assess the marginal/internal fit, as well as a mechanical fatigue test (20 Hz, initial load = 100 N/5000 cycles; step-size = 50 N/10,000 cycles until a threshold of 1500 N, then, the step-size was increased if needed to 100 N/10,000 cycles until failure or a threshold of 2800 N) to evaluate the restorations long-term behavior. Complementary analysis of the fracture features and surface topography in scanning electron microscopy was performed. Three-way ANOVA and Kaplan-Meier test (α = 0.05) were performed for marginal/internal fit, and fatigue behavior data, respectively. PS scanner, CR milling machine, and RC endocrowns resulted in a better marginal fit compared to their counterparts. Still, the PM machine resulted in a better pulpal space fit compared to the CR milling machine. Regardless of the scanner and milling machine, RC endocrowns exhibited superior fatigue behavior than LD ones. LD endocrowns presented margin chipping regardless of the milling machine used. Despite minor differences in terms of fit, the ‘IOS’ and ‘milling machine’ factors did not impair the fatigue behavior of endocrowns. Resin-composite restorations resulted in a higher survival rate compared to glass-ceramic ones, independently of the digital devices used in the workflow.

De novo regeneration of dentin pulp complex mediated by Adipose derived stem cells in an immunodeficient albino rat model (Histological, histochemical and scanning electron microscopic Study)

BackgroundDental tissue engineering is an alternative procedure for restoring damaged dental tissues. Adipose-derived stem cells are a new source of cells for regenerative endodontics in combination with scaffold materials. The descriptive data about this regenerative process is still insufficient. ObjectiveTo evaluate the regenerative potential of Adipose-derived stem cells using a self-assembling polypeptide scaffold for the dentin-pulp complex in an emptied root canal space. Material and Methods40 root segments of human single-rooted teeth were transplanted into the albino rats’ dorsal subcutaneous tissue. Root segments were divided into two groups: group I contained only a self-assembling polypeptide scaffold, and group II contained fluorescent-labeled Adipose-derived stem cells embedded in a self-assembling polypeptide scaffold. The newly formed tissues were assessed on the 60th and 90th days post-transplantation using routine histological examination, Masson trichrome staining, and scanning electron microscopy. ResultsGroup I showed granulation tissue without any signs of predentin formation or odontoblast-like cells. Group II revealed the presence of predentin tissue along the dentin margin, with arranged odontoblast-like cells. An organized connective tissue with abundant vasculature and calcific masses was observed in the pulp space. ConclusionAdipose-derived stem cells can be considered as alternative stem cells for regenerating the dentin-pulp complex. Dentin pulp complex regeneration utilizing a self-assembling polypeptide scaffold alone would not yield successful results.

Evaluation of residual dentin thickness using quantitative light-induced fluorescence technology.

This study aimed to determine whether a correlation exists between residual dentin thickness and quantitative light-induced fluorescence (QLF) values and, if so, to analyze its tendencies. Forty extracted sound human molars were assigned to filled and unfilled groups. The teeth were submerged in a mold with clear acrylic resin. Red utility wax was inserted into the pulp chamber space in the filled group to simulate vital pulp. The specimen was sectioned longitudinally to observe the inside of the pulp space. The samples were cut horizontally from the highest point of the pulp space 2mm apart. QLF images were then taken of 2mm, 1mm, and 0.5mm samples using the QLF-D Biluminator™ 2 + system. Three operators independently evaluated the QLF images, and the statistical analysis was conducted using one-way analysis of variance, Pearson correlation coefficients, and intraclass correlation coefficients. In the filled group, the mean ΔF values for residual dentin thicknesses of 2mm, 1mm, and 0.5mm were - 3.22, - 7.84, and - 11.52, respectively. In the unfilled group, the mean ΔF values were 0, - 6.90, and - 10.14, respectively. A positive correlation was found between residual dentin thickness and ΔF values (P < 0.05). The intraclass correlation coefficients for observations made by the three operators for the filled and unfilled groups were 0.831 and 0.917, respectively (P < 0.05). In conclusion, residual dentin thickness and ΔF values were significantly correlated and had a highly positive correlation regardless of the QLF device operator.

Predictive Machine learning Models for necessity Supplemental Anesthesia in Endodontic treatment

Purpose: In cases of irreversible pulpitis, controlling intraoperative endodontic discomfort is extremely difficult, and patient satisfaction plays a big part in this. In order to forecast a diagnostic's and a treatment's outcome, machine learning (ML) has recently been implemented in the fields of medicine and dentistry. The goal of this work was to create machine learning (ML) models that could predict the need for further anesthesia. Methods: According to inclusion and exclusion criteria, this study included 128 individuals with endodontic discomfort. All patients underwent a clinical evaluation and endodontic diagnostic procedures. All interpretation results were entered into a prepared data sheet. All info were statistically evaluated using Github software version ydata-profilling vv4.1.2, configuration config.json, was employed to review the explanatory data for machine learning models for all examination and investigation aspects. By using Pearson correlation, chi 2, Random Forest, and LightGBM, the final feature importance was determined. 20% of the test set and 80% of the train set are observation sets used to build models. Logistic regression F1 and k-nearest neighbors (KNN) F1 were used to assess the performance of the ML model on the train and test sets. Results: For Machine learning models, 11 of the 20 features—such as pulp stone or calcification of the pulp space, pain duration, age, percussion, palpation, response persistent after EPT, dental history, curved root canal, pain persistent after a cold test, and pain severity during a cold test—were important. In logistic regression, F1 for the train set was 0.793, while for the test sets, it was 0.878. Regression using a logistic model had an accuracy of 0.81. KNN F1 for train was 0.781, while for test it was 0.829. The Machine learning model's k-nearest neighbors (KNN) F1 accuracy was 72.86. Conclusion: The trained machine learning models can predict if further anesthetic will be required during endodontic treatment based on the specific feature.

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

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

Frequency of patients presenting with Hand Infection and treatment modalities

Introduction: Infections of the hand are one of the most common infections reported by the caring physicians and surgeons. Common types of hand infections include: bite wounds, felon, necrotizing fasciitis, paronychia, flexor tenosynovitis, subcutaneous/cellulitis, osteomyelitis and septic arthritis. Aims: The aim of this study to identify the main etiological factors, possible complications due to acute hand infection and treatment modalities performed in our selected group of patients. Materials and Method: This was a prospective Cross Sectional Observational Study based on 58 patients conducted at King Abdullah Hospital, Bisha, Saudi Arabia. Period of study was one year from May 2022 to April 2023. Patients of all age group were included. Male patients were 16 (27.5%) while females were 42 (72.4%). Result: Most of the patients were gardener / farmer 15 (25.9%), minor children 12 (20.7%), and housewife / maid 9 (15.5%). Major mechanism of injury was penetrating trauma 41 (70.7%). Majority of the patients were between 20 years to 50 years of age group. The risk factors associated with hand infection includes diabetes mellitus 13 (22.4%) and hypertension 5 (8.6%). The smokers were 13 (22.4%) patients. Most of the patients were Saudi national 30 (51.7%) followed by Egyptian12 (20.7%), Pakistani and Sudanese 4 (6.9% each). Surgical intervention includes, incision and drainage in 40 (68.9%) cases while amputation was performed in 3 (5.2%) cases. There were 15 (25.9%) patients treated with conservative treatment protocol. Major organisms causing infection was staphylococcus aureus 28 (48.30%) including methicillin resistant staphylococcus aureus (MRSA). There was no growth in 5 (8.6%) patients and for 19 (32.8%) patients no drainage collection was available and therefore their samples were not analyzed for bacteriology. We have categorized the diagnosis into 6 groups as subcutaneous infection 27 (41.5%), acute Paronychia 11 (16.9%), web space infection 10 (15.4%), pulp space infection7 (10.8%), flexor tenosynovitis 6 (9.2%) and midpalmer/thenar 4 (6.2%). Conclusion: Early clinical diagnosis based on occupational history and control of co-morbid disease such as diabetes mellites, smoking etc is effective in the treatment and prevention of hand infection to avoid devastating surgical intervention of partial or total diabetic hand amputation.

Human Gingival Fibroblasts Response to Different Endodontic Sealers: An In Vitro Study

Endodontic treatment aims to eliminate infection of the root canals and fill the dental pulp space. The biocompatibility studies of the sealers used in root canals obturation are crucial since they are applied in direct contact with periradicular tissues. Objective: The aim of this study was to evaluate the cytotoxicity of three root canal sealers—AH Plus, Bio MTA+, and Bio C sealer—on immortalized human gingival fibroblasts. Methods: AH Plus, Bio MTA+, and Bio C sealers were evaluated through incubation in real-time and material-conditioned media. Cells were incubated for 24 h and 72 h, at three different concentrations (1, 10, and 100 mg/mL) of each sealer. The cytotoxic activity of the sealers was assessed by Methyl tetrazolium (MTT) and Sulforhodamine B (SRB) assays. Cell morphology and cytogenetic alterations were studied microscopically. Results: MTT and SRB assays revealed similar results within both approaches. Cell culture exposed to sealers through incubation in real-time revealed a cytotoxic effect of AH Plus at 100 mg/mL. Material-conditioned media study revealed a cytotoxic effect of Bio MTA+ and Bio C, increasing with higher compound concentration and reaching 50% with 100 mg/mL. Regarding the cell’s morphology, Bio C sealer revealed a decrease in cell confluence and several morphological changes. AH Plus and Bio MTA+ did not seem to affect the cell confluence however morphology alterations were observed. In the cytogenetic study, a severe decrease of the mitotic index and a large number of chromosomal aberrations were observed. The present study represents an advance in the understanding of the biocompatibility of AH Plus, Bio MTA+, and Bio C sealers. These sealers demonstrated some cytotoxicity, depending on the concentration used. Although more validation studies are still needed, this study brings very relevant results in terms of cytotoxicity, cell morphology, and cytogenetic alterations. Conclusions: These results could help in the selection of the most appropriate compounds to be used in clinical practice as well as to determine the maximum recommended amounts of each sealer. Clinical Relevance: This study highlights the potential cytotoxic effects of three commonly used root canal sealers on human gingival fibroblasts, with varying degrees of impact depending on the concentration used. The results emphasize the importance of careful consideration when selecting and applying these materials in clinical practice.

A Cone-beam Computed Tomography Evaluation of External Invasive Resorption of Unerupted Teeth. Report of Three Cases

Tooth resorption can occur either physiologically or pathologically and can be classified as internal or external. The term “external invasive resorption” (EIR) has been used to describe lesions originating from any surface defect exposing dentin. The absence of bacterial contamination, an intact pulp space, and a lesion consisting mainly of fibrovascular tissue characterize EIR. This study presents three cases of invasive resorption in unerupted teeth, emphasizing the importance of cone-beam computed tomography (CBCT). In two cases, the primary defect localized on the enamel surface, while in the third case, the focal point of the defect was not clear. CBCT provided detailed visualization of the resorption lesion's size and its relationship with surrounding structures, enhancing the diagnosis of EIR. Histological analysis of the third case confirmed the initial diagnosis. Invasive resorption can occur due to any surface defect in the case of unerupted teeth. Further research and correlation between radiographic and histological analysis are essential for the detection and classification systems in unerupted teeth.

Role of oral microbiota in irreversible pulpitis - Current strategies and future perspectives.

Irreversible pulpitis is an inflammation of the tooth pulp caused by an opportunity-driven invasion of the pulp space by oral microbiota typically prevalent in the oral cavity. Microbial organisms are extensively recognised to be the fundamental cause of endodontic infections and treatment failures. Previously, bacterial species responsible for these infections were largely recognised using conventional microbial culture techniques, lending credence to the widely held belief that anaerobic Gram-negative bacteria frequently enter the pulp space and trigger endodontic infections. The advent of novel technologies grants the advantage of detecting and studying microbial populations via an amalgamation of the modern "Omics" techniques and meticulous bioinformatics analysis, additionally detecting the metatranscriptome, metaproteome and metabolome along with the metagenome. Amongst these analytical strategies, metagenomic analyses are essentially pragmatic for investigating the oral microbiome. Metagenomics favor not only assessment of microbial composition in diseased conditions, but also contributes to detection of novel, potentially pathogenic species inclusive of non-viable bacteria. The present review describes current knowledge of root canal microbiome, including its composition and functional attributes, the novel strategies available for detection of microbiome as well as challenges associated and provides some crucial pointers for areas of future research.

Assessment of the Correlation Between Systemic Conditions and Pulp Canal Calcification: A Case-Control Study.

Pulp canal calcification is a dental condition that is characterized by the deposition of mineralized tissue within the dental pulp space. While it is primarily a local phenomenon, recent studies have suggested a potential link between pulp calcification and systemic diseases. This study aimed to determine the correlation between certain systemic diseases, medications, and the presence of pulp canal calcification. Second, it aimed to estimate the prevalence of pulp calcification in the smoker population. A pair-matched case-control observational study was conducted from June 2022 to June 2023 at the Faculty of Dentistry, King Abdulaziz University. Digital periapical and bitewing radiographs were used for case-based sampling. Patients were categorized into two study groups: the cases group (n=100), consisting of patients with pulp canal calcification including either pulp stone, pulp canal obliteration, or both. Whereasthe control group (n=100), consisted of patients without pulp canal calcification.Detailed medical histories were obtained to identify the presence of systemic diseases. Additionally, systemic medications and smoking status were documented. The participants were divided into two groups; cases (n=100), diagnosed with teeth calcifications and confirmed by radiographic examination, and controls (n=100), showing no evidence of teeth calcifications. Among the patients in the calcification group, 26% had a history of systemic disease compared to 17% in the control non-calcification group with no significant difference between both groups. No correlation between certain medications and pulp canal calcification. Smoking did not demonstrate a statistically significant association with teeth calcifications (p > 0.05). Pulp calcification on routine radiographic examination could indicate an underlying unnoticed systemic disorderthat demands accurate referral and subsequent therapy.

Conventional root canal treatment of a mandibular second premolar with three roots and three canals performed by an undergraduate student: A case report with 8-year follow-up

Abstract In developing countries, such as Sudan, there is a lack of advanced endodontic technologies and specialized endodontists. Therefore, challenging endodontic cases are inevitability encountered by undergraduate students and general dental practitioners. Their ability to manage such cases can significantly impact the decision of whether a tooth is saved or extracted. Here, we report the case of a 24-year-old male patient who presented to our clinic with pain in the mandibular second premolar. Tooth #45 had caries and was tender to vertical percussion. An intraoral periapical radiograph (IOPR) revealed a wide periodontal ligament space and thickened lamina dura, with the deep occluso-distal decay reaching the pulp space. A radiograph obtained using the tube shift technique revealed the presence of three distinct roots and canals. The patient was diagnosed with symptomatic irreversible pulpitis and apical periodontitis. His root canal treatment (RCT) was performed by a 5th-year undergraduate student using the conventional radiography technique, hand file instruments, and lateral condensation obturation. At the 8-year follow-up visit, the tooth crown was lost, the patient was asymptomatic, and the IOPR revealed normal periapical bone. This case demonstrates the importance of training undergraduate students from developing countries to perform RCT for challenging endodontic cases using conventional techniques.

The investigation of WNT6 and WNT10A single nucleotide polymorphisms as potential biomarkers for dental pulp calcification in orthodontic patients.

The aim of this study is to evaluate if single nucleotide polymorphisms (SNPs) in WNT6 and WNT10A are associated with the risk of dental pulp calcification in orthodontic patients. This cross-sectional study followed the "Strengthening the Reporting of Genetic Association Studies" (STREGA) guidelines. Panoramic radiographs (pre- and post-orthodontic treatment) and genomic DNA from 132 orthodontic patients were studied. Dental pulp calcification (pulp stones and/or pulp space narrowing) was recorded in upper and lower first molars. The SNPs in WNT6 and WNT10A (rs7349332, rs3806557, rs10177996, and rs6754599) were assessed through genotyping analysis using DNA extracted from buccal epithelial cells. The association between pulp calcification and SNPs were analyzed using allelic and genotypic distributions and haplotype frequencies (p<0.05). Prevalence of dental pulp calcification was 42.4% in the 490 studied molars. In the genotypic analysis, the SNPs in WNT10A showed a statistically significant value for molar calcification (p = 0.027 for rs1017799), upper molar calcification (p = 0.040 for rs1017799) (recessive model), and molar calcification (p = 0.046 for rs3806557) (recessive model). In the allelic distribution, the allele C of the SNP rs10177996 in WNT10A was associated with molar calcifications (p = 0.042) and with upper first molar calcification (p = 0.035). Nine combinations of haplotypes showed statistically significant value (p<0.05). The findings of this study indicates that SNPs in WNT10A and WNT6 are associated with dental pulp calcification in molars after orthodontic treatment and may be considered as biomarkers for dental pulp calcification.

Effect of cone beam Computed tomography voxel size in volume measurement of upper canine prepared pulp space

Effect of cone beam Computed tomography voxel size in volume measurement of upper canine prepared pulp space

3D Organoids for Regenerative Endodontics.

Apical periodontitis is the inflammation and destruction of periradicular tissues, mediated by microbial factors originating from the infected pulp space. This bacteria-mediated inflammatory disease is known to interfere with root development in immature permanent teeth. Current research on interventions in immature teeth has been dedicated to facilitating the continuation of root development as well as regenerating the dentin-pulp complex, but the fundamental knowledge on the cellular interactions and the role of periapical mediators in apical periodontitis in immature roots that govern the disease process and post-treatment healing is limited. The limitations in 2D monolayer cell culture have a substantial role in the existing limitations of understanding cell-to-cell interactions in the pulpal and periapical tissues. Three-dimensional (3D) tissue constructs with two or more different cell populations are a better physiological representation of in vivo environment. These systems allow the high-throughput testing of multi-cell interactions and can be applied to study the interactions between stem cells and immune cells, including the role of mediators/cytokines in simulated environments. Well-designed 3D models are critical for understanding cellular functions and interactions in disease and healing processes for future therapeutic optimization in regenerative endodontics. This narrative review covers the fundamentals of (1) the disease process of apical periodontitis; (2) the influence and challenges of regeneration in immature roots; (3) the introduction of and crosstalk between mesenchymal stem cells and macrophages; (4) 3D cell culture techniques and their applications for studying cellular interactions in the pulpal and periapical tissues; (5) current investigations on cellular interactions in regenerative endodontics; and, lastly, (6) the dental-pulp organoid developed for regenerative endodontics.

Endodontic treatment of teeth that undertook calcic pulp metamorphosis

The pulp-dentin complex is primarily responsible for the color of teeth. Increasing the thickness of the dentin and decreasing or eliminating the pulp tissue implies changing the tooth color. Calcific Metamorphosis of the Pulp, partial or total calcification of the root canal, replaced by sclerotic dentin is often perceived by darkening of the tooth followed by aseptic pulp necrosis. Endodontic treatment in these cases becomes very difficult due to atresia or even total calcification of the pulp space, requiring the use of specific techniques, knowledge and mastery of internal dental anatomy. In this article we present a clinical case in which we performed the root canal of a tooth that suffered Calcific Pulp Metamorphosis, employing an ultrasonic insert in the modeling of the canal.

CYTOTOXICITY TESTING OF A NOVEL CROSSLINKED PRF (C-PRF) DEVELOPED FOR DENTAL PULP TISSUE ENGINEERING PURPOSE

Background- Whole pulp amputation followed by pulp space disinfection and lling with an articial material causes loss of signicant amount of dentin leaving a non-vital and weakened tooth. Regenerative endodontics with its emerging eld of modern tissue engineering has demonstrated promising results using stem cells associated with scaffolds and responsive molecules. [1] Introduction- PRF was recognized as the “second generation” of this family of biomaterials. [6] PRF being tested in pulp tissue engineering by different research groups showed mixed results. (7,8) Research studies have shown that the interactions between the cells and their niche are closely related to physicochemical properties of the scaffolding materials [9, 10]. As PRF is a fragile gel its physical character needs to be improved by cross linking and thereby more longer period of liberation of its growth factors and delayed disintegration in physiological system. Aims and Objectives- Aim of our study was to prepare a very economical and autologous biomaterial for pulp tissue engineering by crosslinking of PRF with tannic acid. Our objective was to detect cytotoxic effect of tannic acid in PRF. Methods and Materials- We followed Choukroun et al. protocol to prepare PRF samples from whole venous blood collected from donors. PRF samples were then cross-linked in freshly prepared TA solution in dapendish for 10 minutes at room temperature. Concentrations of TA 1 wt% was used for preparing samples. After crosslinking, the gels were washed with normal saline for 5 min. to ensure that all excess TA was removed. The viability of cells cultured on the scaffolds was assessed through MTT assay (EZcountTM MTT cell Assay Kit, HiMedia, Mumbai, India). Observations- Both MTT Assay and Phalloidine staining showed favourable results of no clear cytotoxic effects of C-PRF. Conclusion- Based on the results of the cell viability analysis it can be concluded that none of the tannic acid crosslinked PRF created any clear cytotoxicity in the MC3T3 cells. So, C-PRF can safely be used as scaffold for dental pulp or similar tissue engineering purposes.

Effect of Intracoronal Sealing Biomaterials on the Histological Outcome of Endodontic Revitalisation in Immature Sheep Teeth—A Pilot Study

The influence of intracoronal sealing biomaterials on the newly formed regenerative tissue after endodontic revitalisation therapy remains unexplored. The objective of this study was to compare the gene expression profiles of two different tricalcium silicate-based biomaterials alongside the histological outcomes of endodontic revitalisation therapy in immature sheep teeth. The messenger RNA expression of TGF-β, BMP2, BGLAP, VEGFA, WNT5A, MMP1, TNF-α and SMAD6 was evaluated after 1 day with qRT-PCR. For evaluation of histological outcomes, revitalisation therapy was performed using Biodentine (n = 4) or ProRoot white mineral trioxide aggregate (WMTA) (n = 4) in immature sheep according to the European Society of Endodontology position statement. After 6 months' follow-up, one tooth in the Biodentine group was lost to avulsion. Histologically, extent of inflammation, presence or absence of tissue with cellularity and vascularity inside the pulp space, area of tissue with cellularity and vascularity, length of odontoblast lining attached to the dentinal wall, number and area of blood vessels and area of empty root canal space were measured by two independent investigators. All continuous data were subjected to statistical analysis using Wilcoxon matched-pairs signed rank test at a significance level of p < 0.05. Biodentine and ProRoot WMTA upregulated the genes responsible for odontoblast differentiation, mineralisation and angiogenesis. Biodentine induced the formation of a significantly larger area of neoformed tissue with cellularity, vascularity and increased length of odontoblast lining attached to the dentinal walls compared to ProRoot WMTA (p < 0.05), but future studies with larger sample size and adequate power as estimated by the results of this pilot study would confirm the effect of intracoronal sealing biomaterials on the histological outcome of endodontic revitalisation.