Pulp Damage Research Articles

Hall technique in children: A cross-sectional survey among Indian pedodontists

Background: Stainless steel crowns are considered to be a practicable alternative in the restoration of carious primary tooth. This study was done to assess Indian pediatric dentists’ knowledge, attitude, and practice of this technique and related factors with the use of the Hall technique (HT). Methods: A well-structured preused online questionnaire was sent to pedodontists practicing in India through various social media groups and emails. Descriptive statistics were used to characterize survey responses. A Chi-square test was employed to check the distribution of responders using the HT. Statistically P < 0.05 or less was considered statistically significant. Results: A total of 210 pedodontists participated in this survey. 66.20% of the participants have <10 years’ experience; majority of the participants are in private clinical practice in urban areas. 97.14% of Indian pedodontists are aware of HT, and 22.54% regularly practice HT. 37% of the participants has apprehension of change in vertical dimension due to ooclusal changes and 35% of the participants fear of pulpal damage due to Hall technique. A significant number of pedodontists who have passed master of dental surgery (MDS) in pediatric and preventive dentistry <10 years ago (P = 0.034*), those from academic institutions (P = 0.048*), and those from urban areas (P = 0.045*) practice HT. Conclusion: A substantial proportion of the respondents were familiar with the HT, but considerably less number of participants use it regularly in clinical practice. There is a scope for increased practice of this technique so that the children in need of treatment of multisurface carious lesions can benefit.

Green synthesis of nanohydroxyapatite with Elaeagnus angustifolia L. extract as a metronidazole nanocarrier for in vitro pulpitis model treatment

The aim of this study is to introduce a dental capping agent for the treatment of pulp inflammation (pulpitis). Nanohydroxyapatite with Elaeagnus angustifolia L. extract (nHAEA) loaded with metronidazole (nHAEA@MTZ) was synthesized and evaluated using a lipopolysaccharide (LPS) in vitro model of pulpitis. nHAEA was synthesized through sol–gel method and analyzed using Scanning Electron Microscopy, Transmission Electron Microscopy, and Brunauer Emmett Teller. Inflammation in human dental pulp stem cells (HDPSCs) induced by LPS. A scratch test assessed cell migration, RT PCR measured cytokines levels, and Alizarin red staining quantified odontogenesis. The nHAEA nanorods were 17–23 nm wide and 93–146 nm length, with an average pore diameter of 27/312 nm, and a surface area of 210.89 m2/g. MTZ loading content with controlled release, suggesting suitability for therapeutic applications. nHAEA@MTZ did not affect the odontogenic abilities of HDPSCs more than nHAEA. However, it was observed that nHAEA@MTZ demonstrated a more pronounced anti-inflammatory effect. HDPSCs treated with nanoparticles exhibited improved migration compared to other groups. These findings demonstrated that nHAEA@MTZ could be an effective material for pulp capping and may be more effective than nHAEA in reducing inflammation and activating HDPSCs to enhance pulp repair after pulp damage.

Regenerative endodontic treatment of necrotic permanent teeth with pre-eruptive intracoronal radiolucency: a case report.

Pre-eruptive intracoronal radiolucency is a rare dental anomaly with unclear aetiology, generally asymptomatic and diagnosed through routine radiographs. Failure to diagnose and treat it early can lead to rapid pulp damage, potentially compromising root development. The presented clinical report describes a mandibular second premolar with pre-eruptive intracoronal radiolucency that caused early pulp necrosis with arrest of root formation and emphasises the endodontic management using regenerative endodontic therapy.

TRPA1 up-regulation mediates oxidative stress in a pulpitis model in vitro.

Pulpitis is associated with tooth hypersensitivity and results in pulpal damage. Thermosensitive transient receptor potential (TRP) ion channels expressed in the dental pulp may be key transducers of inflammation and nociception. We aimed at investigating the expression and role of thermo-TRPs in primary human dental pulp cells (hDPCs) in normal and inflammatory conditions. Inflammatory conditions were induced in hDPC cultures by applying polyinosinic:polycytidylic acid (poly(I:C)). Gene expression and pro-inflammatory cytokine release were measured by RT-qPCR and ELISA. Functions of TRPA1 channels were investigated by monitoring changes in intracellular Ca2+ concentration. Mitochondrial superoxide production was measured using a fluorescent substrate. Cellular viability was assessed by measuring the activity of mitochondrial dehydrogenases and cytoplasmic esterases. TRPA1 activity was modified by agonists, antagonists, and gene silencing. Transcripts of TRPV1, TRPV2, TRPV4, TRPC5, and TRPA1 were highly expressed in control hDPCs, whereas TRPV3, TRPM2, and TRPM3 expressions were much lower, and TRPM8 was not detected. Poly(I:C) markedly up-regulated TRPA1 but not other thermo-TRPs. TRPA1 agonist-induced Ca2+ signals were highly potentiated in inflammatory conditions. Poly(I:C)-treated cells displayed increased Ca2+ responses to H2O2, which was abolished by TRPA1 antagonists. Inflammatory conditions induced oxidative stress, stimulated mitochondrial superoxide production, resulted in mitochondrial damage, and decreased cellular viability of hDPCs. This inflammatory cellular damage was partly prevented by the co-application of TRPA1 antagonist or TRPA1 silencing. Pharmacological blockade of TRPA1 channels may be a promising therapeutic approach to alleviate pulpitis and inflammation-associated pulpal damage.

The effect of orthodontic Force Application and Tooth Movement on Dental Pulp

This systematic review aimed to conclusively investigate the effect of continuous intrusive force application on human pulpal blood flow (PBF). It is a well-established fact that applying a severe orthodontic force for an extended period can cause irreversible pulpitis and necrosis in the pulp by accelerating the inflammation process. In contrast, utilizing moderate and intermittent forces allows for ample tooth movement, limits pulp damage, and facilitates pulp healing. Materials and methods: A comprehensive search of published studies was conducted in several electronic databases such as MEDLINE, PubMed, EMBASE, Scopus, Web of Science, CINAHL, and the Cochrane Database of Systematic Reviews, as well as Google Scholar. The search was conducted without limitations to find published studies. The results showed that orthodontic forces can lead to a decrease in pulpal blood flow, which causes a reduction in tooth sensitivity. This reduction is indicated by an increase in response thresholds and more negative responses to tooth sensitivity tests. Conclusion: applying a severe orthodontic force over a prolonged period of time can lead to irreversible pulpitis and necrosis in the pulp due to an increase in the inflammation process. However, using moderate and intermittent forces can facilitate sufficient tooth movement while minimizing damage to the pulp. This highlights the importance of the endodontic-orthodontic interface and the need to consider dental pulp health during orthodontic treatment to avoid dental trauma.

In-office Bleaching Activated With Violet LED: Effect on Pulpal and Tooth Temperature and Pulp Viability.

This study evaluated the influence of hydrogen peroxide (HP) with or without titanium dioxide nanotubes (TiO2) associated with violet LED (VL) regarding: a) the temperature change in the pulp chamber and facial surface; b) the decomposition of HP; and c) the cytotoxicity of the gels on pulp cells. The experimental groups were: HP35 (35% HP/Whiteness HP, FGM); HP35+VL; HP35T (HP35+TiO2); HP35T+VL; HP7 (7.5% HP/White Class 7.5%, FGM); HP7+VL; HP7T (HP7+TiO2); and HP7T+VL. TiO2 was incorporated into the bleaching gels at 1%. Eighty bovine incisors were evaluated to determine temperature change in 8 experimental groups (n=10/group). A k-type thermocouple was used to evaluate the temperatures of the facial surface and in the pulp chamber, achieved by enabling endodontic access to the palatal surface, throughout the 30-minute session. HP decomposition (n=3) of gels was evaluated by using an automatic potentiometric titrator at the initial and 30-minute time points. Trans-enamel and trans-dentinal cell viability were assessed with a pulp chamber device as well as enamel and dentin discs (n=6), and the treatment extracts (culture medium + diffused components) were collected and applied to MDPC-23 odontoblast cells to evaluate cell viability according to the MTT test. A temperature increase in the pulp chamber was observed in the presence of VL at 30 minutes (p<0.05) (Mann-Whitney test). Also at 30 minutes, HP35 showed greater decomposition in the presence of VL rather than in its absence (p<0.05) (mixed linear models and the Tukey-Kramer test). HP7 provided greater cell viability than the groups treated with HP35 (p<0.05) (generalized linear models test). Cell viability was significantly lower for HP7 in the presence of VL (p<0.05). Pulpal temperature increased with VL (maximum of 1.9°C), but did not exceed the critical limit to cause pulp damage. Less concentrated HP resulted in higher cell viability, even when associated with VL.

A Finite Element Method Study on a Simulation of the Thermal Behaviour of Four Methods for the Restoration of Class II Cavities.

The possibility of dental pulp damage during dental procedures is well known. According to studies, during finishing and polishing without cooling, temperatures of up to 140 °C or more can be generated. There are many studies that have analysed the influence of the finishing and polishing of fillings on the mechanical parameters, but the analysis of thermal parameters has led to uncertain results due to the difficulty of performing this in vivo. Background: We set out to conduct a study, using the finite element method, to determine the extent to which the type of class II cavity and the volume of the composite filling influence the duration of heat transfer to the pulp during finishing and polishing without cooling. Materials and Methods: A virtual model of an upper primary molar was used, with a caries process located on the distal aspect, in which four types of cavities were digitally prepared: direct access, horizontal slot, vertical slot and occlusal-proximal. All four cavity types were filled using a Filtek Supreme XT nanocomposite. Results: The study showed that the filling volume almost inversely proportionally influences the time at which the dental pulp reaches the critical temperature of irreversible damage. The lowest duration occurred in occlusal-distal restorations and the highest in direct access restorations. Conclusions: based on the results of the study, a working protocol can be issued so that finishing and polishing restorations without cooling are safe for pulpal health.

Mechanical Damage Caused by Compression and Its Effects on Storage Quality of Mandarin.

Mandarin is vulnerable to a range of external loads during processing and shipping, which can cause interior mechanical damage that can happen right away or over time and cause serious rotting when kept in storage. In this study, mandarin was treated to a certain quantity of compression load that did not result in a noticeable rupture of the peel. The interior pulp structure of mandarin was examined for damage prior to peel damage using CT scanning and image reconstruction. An image segmentation method based on mask processing was then used to calculate the pulp damage rate. We examined the variations in physiological activities and internal components between the test group that underwent compression load and the control group that did not undergo this type of stress during storage. The aim was to investigate the factors that contributed to the faster decay of mandarin following mechanical damage. Regression analysis was also used to establish a quantifiable relationship between the amount of compression deformation and the rates of damage and decay of mandarin during storage. The findings demonstrated that mandarin pulp exhibited visible mechanical damage when compression deformation exceeded 8 mm. This led to the disruption of physiological processes like respiration and polysaccharide breakdown, which in turn decreased the hardness of the fruit and sped up its rotting. This study identifies the critical range of compression deformation that leads to the beginning of pulp damage in mandarins. Additionally, it clarifies the quality deterioration mechanism of mandarins that have been subjected to compression damage during the storage period. Therefore, in practical production, various methods of picking, sorting, and collecting mandarins can be optimized to control the amount of compression deformation within a suitable range. This will reduce the probability of pulp damage. According to the study's conclusions, storage conditions can be optimized to regulate the physiological activities of mandarins in a targeted manner. This can minimize the probability of fruit decay and reduce economic losses.

Root and canal morphology of mandibular second molar

Background: The mandibular second molar is the main chewing tooth and often suffer from pulp damage due to the misalignment of the mandibular third molar. In addition, it’s C-shaped root canal system is a challenge for endodontic treatment. This emphasizes the significance of tooth morphology and root canal system study which can contribute to anthropology, as well as Odonto-Stomatology. Purpose: The objective of this study was explore the morphology and root canal system of the mandibular second moalar in order to provide indicators dentistry applications. Materials and methods: Preclinical (in vitro) study was conducted on 48 mandibular socond molars which was collected in Thua Thien Hue province from December 2021 to June 2022. The teeth were measured externally and determine the shape of the roots. The canal system was examined with two methods including clearing technique and Cone Beam CT. Results: The average length of mandibular second molar was 20.37 ± 1.28 mm. 81.2% of teeth had one root, and 18.8% had two. The teeth with C-shaped roots accounted for 31.2%. The majority of distal roots possessed a simple type I (single canal) configuration. While the canal system of mesial roots was more complex which contained two canals, of which type I, II, III, IV were the most prevalent. C-shaped canal morphology was observed in 31.2% of the examined teeth. Conclusion: The root canall system of mandibular second molar was complex, the percentage of C-shaped canal was high (31.2%). There was similarlu results of two methods of clearing technique and Cone Beam CT in examining the root canal system of mandibular second molars. Key words: mandibular second molar, root canal system, C-shaped root, C-shaped root canal.

Effects of mineral trioxide aggregate and methyl sulfonyl methane on pulp exposure via RUNX2 and RANKL pathways.

The aim of this study was to determine the therapeutic effects of mineral trioxide aggregate (MTA) and methyl sulfonyl methane (MSM) on pulp damage due to pulp exposure through the RUNX2 and RANKL pathways. Seventy-two male Sprague-Dawley rats aged 4-6months and weighing 250-300g were divided into healthy, control, MTA, and MSM groups. After experimental applications, all rats at 2, 4, and 8 weeks were killed anesthetically with xylazine hydrochloride (Rompun, Bayer) 30mg/kg and ketamine hydrochloride (Ketalar, Pfizer) 50mg/kg injections (i.p.). We observed that necrotic odontoblasts, edema, inflammation, and vascular congestion findings were reduced from week 2 to week 8 in the MSM treatment group after pulp capping compared to the control group and MTA group. Similarly, we found a decrease in RUNX2 and RANKL levels in the MSM application group compared to the control and MTA groups (p < 0.05). MSM material has shown therapeutic effects on pulp capping treatment-induced pulp injury via increased RUNX2 ve RANKL expression.

Perception of Prophylactic Root Canal Therapy for Teeth used as Abutments in Fixed Partial Dentures among Dental Surgeons in Maharashtra and Kerala: A Questionnairebased Cross-sectional Survey

Introduction: The pulps of healthy teeth used as abutments for Fixed Partial Dentures (FPD) undergo mechanical and thermal stresses during tooth preparation. The remaining dentin thickness, the heat produced during tooth preparation, and the permeability of dentinal tubules influence the severity of pulpal injury. Prophylactic Root Canal Therapy (RCT) could be an option to provide better outcomes for FPD treatment. Aim: To assess dentists’ perception regarding the need for prophylactic RCT of abutment teeth in FPD through a questionnaire. Materials and Methods: A Questionnaire based Cross-sectional Surve was conducted among 200 dental professionals in the Indian states of Kerala and Maharashtra over a period of two months. The participants included dental professionals from private clinics, dental Institutions, and postgraduate students in these states. The Chi-square test of proportion was performed to assess significant differences between each response. Results: Total 67 out of 200 practitioners, accounting for 33.5%, recommended prophylactic RCT, while 60 (30%) practitioners disagreed with it. A total of 152 (76%) practitioners suggested clinical assessment of abutment teeth before starting the tooth preparation. Total 70 (35%) practitioners had never experienced pulpal damage in abutment teeth in their clinical practice. In contrast, 127 (63.5%) practitioners experienced pulpal damage in less than half of the total cases, and 3 (1.5%) practitioners experienced failures like pulp necrosis or irreversible pulpitis in more than half of the total cases. Conclusion: Total 33.5% of the surveyed dental practitioners recommended prophylactic endodontic treatment for abutment teeth in FPDs. Implementing precise elective RCT guidelines into dental curricula was suggested as a potential avenue to enhance decision-making and improve patient outcomes by reducing the incidence of pulpal damage beneath FPDs.

Effect of translucency and absorbance of composite on temperature change during photopolymerization.

This study investigated the effect of translucency and absorbance of conventional (FiltekTM-Z350-XT) and bulk-fill (Tetric®-N-Ceram) composites on temperature change during photopolymerization, using a non-contact infrared sensor. Three shades from each composite were selected to prepare disk-shaped specimens (n=3), which then photopolymerized with LED-light for 20 s. A second light exposure was performed on the photopolymerized specimens. The first peak temperature rise during composite photopolymerization (ΔTtotal), second peak temperature rise by the light (ΔTlight), and net peak temperature rise by composite curing heat (ΔTcomposite) were obtained from the temperature change vs. time curve. The changes in ΔTtotal and ΔTlight with varying the composite shade were greater than those in ΔTcomposite. The conventional composite showed higher ΔTtotal and ΔTlight than bulk-fill composite. ΔTtotal and ΔTlight increased as translucency parameter decreased, and absorbance increased. The potential risk for heat-induced pulpal damage should be considered when selecting a composite shade, especially for deep cavities.

THE EFFECTIVENESS OF CHITOSAN NATURAL SOURCES ON PULP TISSUE REGENERATION

Background: Dental pulp plays a role in forming dentin, providing nutrition, and sensing harmful stimuli to the tooth. Pulp damage can occur due to physical, chemical, and biological factors. A regenerative therapy was developed so that the pulp can regenerate its tissue and the teeth can survive in the oral cavity with vital conditions. Tissue engineering is a principle developed in the treatment of pulp tissue regeneration. The main elements of tissue engineering are stem cells, scaffolds, and growth factors. Scaffolds are elements that support cell organization, migration, proliferation, differentiation, and vascularization. One example of a biomaterial that can be used as a scaffold is chitosan. Chitosan has been proved to be suitable as a biomedical material because it has several beneficial properties including increasing cell proliferation, attachment, and differentiation. Purpose: This study aims to determine the most effective natural ingredient chitosan for pulp tissue regeneration. Methods: This study used the literature review method with a narrative review procedure. The literature was searched using Google Scholar, Science Direct, ProQuest, and PubMed. Results: The results of the study from 6 articles showed that chitosan from shrimp, crab, and mushroom had the potential to increase pulp tissue regeneration in terms of 3 indicators (cell proliferation, attachment, and differentiation). Conclusion: The most effective chitosan from natural sources for pulp regeneration is shrimp chitosan and mushroom chitosan. Keywords: Chitosan, Natural Sources, Pulp Tissue Regeneration

The impact of different polishing systems on yttria-stabilized tetragonal zirconia polycrystalline crowns in relation to heat generation.

To investigate the heat generation on yttria-stabilized tetragonal zirconia polycrystalline (Y-TZP) crowns during polishing with coarse and fine polishing systems at various speeds. Two polishers (coarse and fine) at three polishing speeds were investigated. Two simulation models of the first mandibular molars were prepared for full coverage Y-TZP restorations with different reduction dimensions. Preheated water was pumped into the abutment chamber, to simulate the intrapulpal temperature and blood flow. Twelve Y-TZP crowns (3M™ Lava™ Esthetic) were milled for each prepared tooth abutment and each cusp (n = 10) was individually ground for 30 s and polished for 2 min. Thermocouple wire was secured to the intaglio surface of the crown and linked to a data logger for recording temperature changes. Selected scanning electron microscopy (SEM) images of the treated surfaces and polishers were analyzed. The data was statistically analyzed using Prism 9. The highest temperature rise was observed in the 20,000 RPM polishing speed groups for both coarse and fine polishing, and higher than the threshold value of 5.5°C for pulp damage. The Kruskal-Wallis test, revealed statistically significant differences (p < .0001) in heat generation between low (10,000 RPM) and high (20,000 RPM) polishing speeds. High-speed polishing at 20,000 RPM generated the most heat over the threshold of 5.5°C, which would threaten the dental pulp. The results suggest that a cautionary approach should be taken to high-speed intraoral polishing. Dental clinicians should be aware of the choice of polishing systems and speeds to avoid pulp damage from intraoral polishing of Y-TZP restorations.

The Effects of Different Drugs with Anti-Inflamatory Potential in Prevention of Pulp Damage During the Teeth Bleaching

Abstract This paper aims to collect all the necessary information and conclusions which deal with the anti-inflammatory drugs within the scope of teeth bleaching, and which are rooted in scientific research. It is a well-known fact that the teeth whiteners / bleachers are at the same time a very aggressive agents, which opened up the question of the safety of their application. The most frequently applied bleaching agents are the hydrogen-peroxide (H2O2) and carbim peroxide (CH6N2O3), therefore this paper will be based on the research which included these two agents. The first studies were directed towards investigating the outcome / impact on the enamel, i.e. if there is direct surface damage of the enamel layer after the use of such agents. However, bearing in mind that the clinical practice has shown that in a number of cases there arises the sensitivity of teeth in the form of painful sensation after the bleaching treatment, some researches were directed towards the estimation of the permeability of the enamel and dentin for the bleaching agent, and later the effect on the pulp tissue. Along with the existing proof about the irritability of these agents to the pulp tissue, the modern research have the idea of looking into the effects of the anti-inflamatory drugs as the accompanying and prevention therapy of any of the irreversible damage of the pulp. On one hand the application of these drugs can reduce the sensitivity and painfulness of the teeth, which makes the intervention pleasant for the patient, but on the other hand the intervention becomes completely justifiable from the aspect of safety and the basic principle primum non nocere. The anti-inflammatory drugs which will be the topic of this study are H hydrocortisone, acetaminophen, ipobruphen and etodolac. Taking into consideration the vasoconstrictive and anti-oxidative effect, the anti-inflammatory effect of the carvedilol will be looked into, which belongs to the group of beta blockers. Based on available informations it can be noticed that the most efficient anti-inflammatory effect in teeth whitening is achived by hydrocortisone.

Intercellular mitochondrial transfer alleviates pyroptosis in dental pulp damage.

Mitochondrial transfer is emerging as a promising therapeutic strategy for tissue repair, but whether it protects against pulpitis remains unclear. Here, we show that hyperactivated nucleotide-binding domain and leucine-rich repeat protein3(NLRP3) inflammasomes with pyroptotic cell death was present in pulpitis tissues, especially in the odontoblast layer, and mitochondrial oxidative stress (OS) was involved in driving this NLRP3 inflammasome-induced pathology. Using bone marrow mesenchymal stem cells (BMSCs) as mitochondrial donor cells, we demonstrated that BMSCs could donate their mitochondria to odontoblasts via tunnelling nanotubes (TNTs) and, thus, reduce mitochondrial OS and the consequent NLRP3 inflammasome-induced pyroptosis in odontoblasts. These protective effects of BMSCs were mostly blocked by inhibitors of the mitochondrial function or TNT formation. In terms of the mechanism of action, TNF-α secreted from pyroptotic odontoblasts activates NF-κB signalling in BMSCs via the paracrine pathway, thereby promoting the TNT formation in BMSCs and enhancing mitochondrial transfer efficiency. Inhibitions of NF-κB signalling and TNF-α secretion in BMSCs suppressed their mitochondrial donation capacity and TNT formation. Collectively, these findings demonstrated that TNT-mediated mitochondrial transfer is a potential protective mechanism of BMSCs under stress conditions, suggesting a new therapeutic strategy of mitochondrial transfer for dental pulp repair.

Effect of Ceramic and Dentin Thicknesses and Type of Resin-Based Luting Agents on Intrapulpal Temperature Changes during Luting of Ceramic Inlays.

The adhesive cementation of ceramic inlays may increase pulpal temperature (PT) and induce pulpal damage due to heat generated by the curing unit and the exothermic reaction of the luting agent (LA). The aim was to measure the PT rise during ceramic inlay cementation by testing different combinations of dentin and ceramic thicknesses and LAs. The PT changes were detected using a thermocouple sensor positioned in the pulp chamber of a mandibular molar. Gradual occlusal reduction obtained dentin thicknesses of 2.5, 2.0, 1.5, and 1.0 mm. Light-cured (LC) and dual-cured (DC) adhesive cements and preheated restorative resin-based composite (RBC) were applied to luting of 2.0, 2.5, 3.0, and 3.5 mm lithium disilicate ceramic blocks. Differential scanning calorimetry was used to compare the thermal conductivity of dentin and ceramic slices. Although ceramic reduced heat delivered by the curing unit, the exothermic reaction of the LAs significantly increased it in each investigated combination (5.4-7.9 °C). Temperature changes were predominantly influenced by dentin thickness followed by LA and ceramic thickness. Thermal conductivity of dentin was 24% lower than that of ceramic, and its thermal capacity was 86% higher. Regardless of the ceramic thickness, adhesive inlay cementation can significantly increase the PT, especially when the remaining dentin thickness is <2 mm.

Pulp fiction or pulp fact-does orthodontics damage pulpal tissue?

Electronic databases PubMed, Scopus and Embase were systematically searched and restricted to articles published between February 2009 and 2022. Studies were categorized using the modified method by the Swedish Council of Technology Assessment in Health Care. 20 studies were included, one of which was categorized as high quality (Grade A) and 19 of which were of moderate quality (Grade B). Exclusion criteria included articles with insufficient descriptions of reliability and reproducibility testing, review articles and case reports, and studies including traumatised teeth. Three independent authors examined titles, abstracts and full texts of relevant articles against the inclusion criteria. Disagreements were resolved by discussion. Retrieved studies were assessed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Data extracted included tooth movement performed, the appliance and force used, follow-up of subjects, changes in pulpal blood flow (PBF), tooth sensibility, expression of inflammation-related proteins, along with pulpal histology and morphology changes during tooth movement (intrusion, extrusion and tipping). Overall risk of bias was unclear. A reduction in pulpal blood flow and tooth sensibility due to the application of orthodontic forces was reported by studies included in the review. Increases in the activity of proteins and enzymes related to inflammation of the pulp was reported. Two studies reported histological changes of the pulpal tissues related to orthodontic treatment. Orthodontic forces cause multiple temporary detectable changes in the dental pulp. The authors conclude there are no clear signs of permanent pulpal damage to healthy teeth due to the application of orthodontic forces.

Crucial Triad in Pulp-Dentin Complex Regeneration: Dental Stem Cells, Scaffolds, and Signaling Molecules

BACKGROUND: Pulp damage can lead to dentinogenesis impairment, irreversible pulpitis, or pulp necrosis. Despite being the most used endodontic procedure to treat damaged pulp, root canal therapy only results in nonvital teeth which are prone to fractures and secondary infection. Pulp-dentin regeneration has a potential to regenerate structure similar to normal pulp-dentin complex, and can be achieved by combining dental stem cells, scaffold, and signaling molecules. This article reviews the role of various types of dental stem cells, scaffolds, signaling molecules, and their combinations in regenerating pulp-dentin complex.CONTENT: Dental pulp stem cell (DPSC), stem cell from human exfoliated deciduous teeth (SHED), and dental follicle stem cell (DFSC) were reported to regenerate pulp-dentin complex in situ. SHED might be more promising than DPSCs and DFSCs for regenerating pulp-dentin complex, since SHED have a higher proliferation potential and higher expression levels of signaling molecules. Scaffolds have characteristics resembling extracellular matrix, thus providing a suitable microenvironment for transplanted dental stem cells. To accelerate the regeneration process, exogenous signaling molecules are often delivered together with dental stem cells. Scaffolds and signaling molecules have different regenerative potential, including induction of cell proliferation and migration, formation of pulp- and/or dentin-like tissue, as well as angiogenesis and neurogenesis promotion.SUMMARY: Combinations of dental stem cells, scaffold, and signaling molecules are important to achieve the functional pulp-dentin complex formation. Current trends and future directions on regenerative endodontics should be explored. The right combination of dental stem cells, scaffold, and signaling molecules could be determined based on the patients’ characteristics. Incomplete pulp-dentin regeneration could be overcome by applying dental stem cells, scaffold, and/or signaling molecules in multiple visits.KEYWORDS: pulp-dentin regeneration, regenerative endodontics, dental stem cells, scaffold, signaling molecules

In-situ nano-Ag coated gutta percha cones to counteract internal endodontic failures through bacterial infections

Root canal treatment is the most effective treatment for pulpal damage. But this treatment suffers major limitation i.e., bacterial infections lead to endodontic failures and flare-ups. To counteract bacterial infections, an anti-bacterial coating i.e., Ag NPs have been introduced over the gutta percha's surface (dental filler) through a simple in-situ coating technique. Further, the coating duration has been optimized to achieve an uniform Ag NPs coating. The coated Ag NPs are characterized using XRD where the phase is identified as face-centered cubic. FESEM analysis is performed for the gutta percha after being coated with Ag NPs for 30 min, 60 min, and 60 + 60 min where the FESEM images substantiate the fact as the coating time increases, the population of Ag NPs on gutta percha also increases and consequently, its anti-bacterial activity increases validated through the zone of inhibition and colony counting studies. The mechanism behind the antibacterial activity is elucidated using assays and found that Ag+ ionic release from the Ag NPs coated gutta percha is responsible. Moreover, the stability of the coating is assessed and found to display comparable antibacterial activity as that of the coated specimen (before stability testing) substantiating the durability of the coating. From all the obtained results, the coating system developed in this study can serve as a potential antibacterial coating for gutta percha.