Endodontic microsurgery has reduced the degree of treatment trauma compared with traditional apical surgery and further increased the success rate of natural teeth retention. However, when root apices of the mandibular posterior teeth are far from the buccal cortical bone surface or near to the inferior alveolar nerve, the operational difficulty of endodontic microsurgery increased greatly. Orthodontic treatments may be helpful to decrease the difficulties. In this case, the roots of a highly calcified mandibular molar diagnosed as previously initiated, symptomatic apical periodontitis were moved initially buccally by orthodontic treatment in 2 months. Then, endodontic microsurgery was completed. The tooth remained asymptomatic and functional with a radiographically healing periapical lesion at the 4-, 12-, and 24-month follow-ups.
Introduction: The purpose of this study was to evaluate the effect of 5 different curvature locations on the fatigue resistance of thermomechanically treated nickel-titanium (NiTi) files and superelastic NiTi files at body temperature and to document the corresponding phase transformations. Methods: EndoSequence (ES; Brasseler USA, Savannah, GA), EndoSequence CM (ESCM, Brasseler USA), K3 (SybronEndo, Orange, CA), K3XF (SybronEndo), and Vortex Blue (VB; Dentsply Tulsa Dental Specialties, Tulsa, OK) NiTi files (size 25/.04) were subjected to fatigue tests inside customized artificial canals containing a curvature of 60 degrees and a 3-mm radius. There were 5 different canals based on the location of initial curvature; these included groups in which the distance between the canal orifice and the location of the curvature (DOC) was 5, 6, 8, 10, and 11 mm. The model canal was immersed in water at 37 degrees C +/- 1 degrees C. The number of cycles to failure (N-f) was recorded, and the fracture surface of the fragments was examined by scanning electron microscopy. Two unused files of each brand were examined by differential scanning calorimetry. Results: The N-f was highest in the 10-mm and 11-mm DOC groups and lowest with the 5-mm and 6-mm DOC groups (P < .05). ESCM files had the highest fatigue resistance followed by the VB, K3XF, K3, and ES files (P < .05). ESCM files had the highest N-f (P <.05), and ES and K3 files had the lowest N-f (P < .05) depending on the curvature location. Two endothermic peaks were observed on the heating curve of the heat-treated files (ESCM, K3XF, and VB). Conclusions: The location of the canal curvature had a significant effect on the fatigue resistance of both heat-treated and superelastic NiTi files. The fatigue life of files in the coronal curve was quite short.
Introduction: The aim of this study was to establish an intrusive luxation model in rats and observe the pulpal and periodontal outcomes. Methods: The intrusion was experimentally induced by an application of 20-N force on the occlusal surface of maxillary right second molar along the tooth axial using a striking instrument in 3-week-old male Sprague-Dawley rats. Thirty rats were divided into 6 groups (n = 5) and were sacrificed after 3, 7, 14, 30, 60, and 90 days of the surgery. The occurrence of pulpal and periodontal complications was observed by micro computed tomographic scanning and hematoxylin-eosin staining. Results: All experimental teeth were fully intruded into the alveolar bone with their occlusal surface located at the cervical level of the adjacent first molar. Spontaneous re-eruption initiated at 7 days. At 14 days, 4 teeth (80%, 4/5) partially re-erupted, whereas 2 (40%), 3 (75%), and 4 (100%) teeth completely re-erupted at 30, 60, and 90 days, respectively. Pulp degeneration and inflammation mainly occurred in 4 teeth at 3 days, 5 at 7 days, and 2 at 14 days; after 14 days, pulp calcification was observed in 8 teeth. Ankylosis and replacement root resorption mainly occurred in 1 tooth at 30 days, 2 teeth at 60 days, and 3 at 90 days. Marginal bone loss was observed in 3 teeth (60%) at 30 days, 3 (75%) at 60 days, and 2 (50%) at 90 days. Conclusions: An animal model of intrusive dentoalveolar trauma was successfully established in rats. Pulpal and periodontal complications similar to clinical tooth intrusion were observed, which provided a basis for exploring the mechanisms of complications in the future.
External root resorption (ERR) is often a complication of traumatic injury to the teeth. Traditionally, external inflammatory root resorption is treated with calcium hydroxide. The outcome of ERR, especially replacement resorption, is unpredictable. The purpose of the present case report was to describe regenerative endodontic procedures (REPs) for 1 replanted avulsed tooth with severe external root resorption and root perforation (tooth #9) and 1 extruded tooth (tooth #8). A 9-year-old girl was referred for the treatment of teeth #8 and #9 4 months after the initial trauma. Clinical examination showed that tooth #9 had a sinus tract present near the periapical area, was tender to percussion and palpation, and did not respond to pulp sensibility tests. Tooth #8 responded to pulp sensibility tests. Periapical radiographic and cone-beam computed tomographic examination showed that tooth #9 had a periapical radiolucent lesion and severe ERRs with a root perforation. Tooth #9 was diagnosed with a necrotic pulp and symptomatic apical periodontitis. Regenerative endodontic procedures (REPs) were initiated. Tooth #8 became nonresponsive to pulp sensibility tests and developed a periapical lesion 12 months after REPs of tooth #9 and was also treated with REPs. The clinical symptoms and apical lesions resolved for both teeth after REPs. The severe ERRs were arrested, and root perforation was repaired for tooth #9. Teeth #8 and #9 underwent canal obliteration by hard tissue formation after REPs and were in function at 18 months and 30 months, respectively. REPs may be used to manage traumatized immature permanent teeth with a necrotic pulp and apical periodontitis associated with severe ERR and root perforation.
Introduction: The purpose of this study was to investigate the resumption of endodontic practices in Hubei Province, China 1 month after the end of the lockdown. Methods: A Web based survey was sent to 1069 active endodontic specialists and general dentists who provided endodontic care in Hubei Province from May 7 to May 9, 2020. The survey consisted of 18 questions on demographics, the current situation of endodontic practice for the participants, and concerns regarding contracting or spreading the virus in newly opened endodontic practices. Results: A total of 322 participants completed the survey. Most respondents (62%) were from Wuhan. Almost 83% of the respondents have resumed their endodontic practice partially or fully. Most respondents in practice (99%) would take measures to screen patients before treatment including paid screening measures. More than 93% of the respondents reported having taken special measures for routine endodontic treatment at this stage, with the most common measure taken being wearing an N95 mask. The rubber dam was recognized as efficient in preventing infection by most respondents. Many respondents were concerned about contracting coronavirus disease 2019 (COVID-19) as a result of routine endodontic practice at this stage, and respondents with more than 11 years of endodontic experience were significantly less concerned about infection compared with those with fewer than 5 years of experience (P<.05). Conclusions: There is a fear of contracting/spreading COVID-19 among endodontic clinicians, the fear is negatively associated with years of practice, and most clinicians believe that rubber dam isolation can protect them and their patients from COVID-19.
Introduction: The aims of this study were to evaluate the methodological quality of randomized controlled trials (RCTs) recently published in endodontics and to investigate the influences of methodological characteristics on the magnitude of treatment effects. Methods: PubMed was searched for RCTs published from October 2013 to October 2018 in 3 leading endodontic journals. The methodological quality of the included studies was determined by using the Cochrane Collaboration risk of bias (RoB) tool. The estimates of intervention effects were expressed or calculated as odds ratios and the standardized mean difference for binary and continuous outcomes, respectively. Meta-regression analyses and Monte Carlo permutation tests were performed to identify the association between RoB and intervention effect estimates. Results: A total of 121 RCTs were identified as eligible for the current study. For both the studies with binary and continuous outcome measures, the domain of blinding of participants and personnel had the highest percentage of high RoB. For binary outcomes, methodological deficiencies in allocation concealment tended to produce exaggerated treatment effects. For continuous outcomes, risk regarding blinding of participants and personnel and incomplete outcome data were more likely to provide overestimated trial results. Conclusions: The methodological quality of RCTs within endodontics is suboptimal, and these methodological deficiencies could exaggerate intervention effect estimates in endodontic RCTs. Better trial methodology and more explicit reporting are needed to improve the reliability of evidence in endodontic RCTs.
Introduction: This study aimed to use nanobioactive glass (nBG) to guide the directional migration of stem cells and odontogenic differentiation on primary dentin, which are important for the functional regeneration of pulp-dentin tissue. Methods: Human bone marrow stem cells (BMSCs) were cocultured with 0,5 mg/mL nBG. The cell-biomaterial interaction was monitored using the IncuCyte S3 live cell imaging system (Essen BioScience, Ann Arbor, MI). The adhesion and morphology of BMSCs growing on nBG-coated dentin were assessed at 2 hours and 3 days. The chemotaxis effect of nBG-coated dentin on BMSCs was tested using a 3-dimensional collagen gel model. Subcutaneous transplantation of nBG-treated dentin slices into nude mice was used to investigate cell homing and odontogenic differentiation in vivo. Results: nBG particles showed good biocompatibility, and they were gradually degraded and relocated during interactions with BMSCs. BMSCs had better initial attachment to an nBGcoated dentin surface than to an untreated dentin surface. Cell migration assays showed that nBG-coated dentin induced significantly more cell migration than untreated dentin. An in vivo study revealed that nBG-coated dentin slices facilitated recellularization and revascularization in the root canal and that dentin sialophosphoprotein-positive cells were detected on the surface of the primary dentin. Conclusions: nBG recruits stem cells to move toward dentin and further promotes cell adhesion and odontogenic differentiation on primary dentin, which help regenerate the biomimetic structure of pulp-dentin tissue.
Introduction: Calcium hydroxide has been used as a traditional pulpotomy agent for a long time but has some disadvantages. iRoot BP Plus (Innovative Bioceramix Inc, Vancouver, Canada) is a newly developed, ready-to-use calcium silicate based bioactive ceramic with excellent bioactivity and sealing ability. However, whether iRoot BP Plus shows superiority over calcium hydroxide as a pulpotomy material on permanent incisors with complicated crown fractures remains unknown. Methods: This research included 205 permanent incisors with complicated crown fractures. These teeth were treated with pulpotomy and divided into 2 groups according to the pulpotomy material (105 treated with iRoot BP Plus and 100 with calcium hydroxide). Clinical and radiographic information was collected during the 12- to 24-month follow-up period. The formation of reparative dentin bridges and pulp canal obliteration were analyzed using radiographs in both groups. Results: The success rates for recall in the average follow-up period of 17.5 +/- 4.4 months (12-24 months) after pulpotomy treatment were significantly different between the 2 groups, with 99% for the iRoot BP Plus group and 93% for the calcium hydroxide group. Reparative dentin bridges were observed in 92.4% of the iRoot BP Plus group and 90% of the calcium hydroxide group, but the difference was not significant. Pulp canal obliteration was observed in 2 teeth (2%) in each group. Conclusions: The success rates obtained in our study indicate that iRoot BP Plus as a pulpotomy agent can be a suitable alternative to calcium hydroxide to manage complicated crown fractures.
Introduction: The suitability of EndoSequence BC Sealer (BC Sealer; Brasseler USA, Savannah, GA) for warm vertical compaction has been questioned. The aim was to evaluate the cytotoxicity and the effect of heating on the physicochemical properties of a new calciumbased root canal sealer (EndoSequence BC Sealer HiFlow [HiFlow]) in comparison with EndoSequence BC Sealer. Methods: Human periodontal ligament fibroblasts were incubated for 1, 2, or 3 days with material extracts of different concentrations, and cell viability was evaluated by Cell Counting Kit-8 (Enzo Life Sciences Inc, Burlington, Ontario, Canada). The setting time, flow, film thickness, microhardness, radiopacity, and radiopacity of the 2 sealers were measured according to ISO 6786/2012. The continuous changes in viscosity were tested by a stress-controlled rheometer at shear rates ranging from 0.01-10 s(-1) and different temperatures, and chemical composition was assessed by Fourier-transform infrared spectroscopy. Results: Cell viability was significantly decreased on day 3 for the 1:4 diluted extract from both materials. The setting time, microhardness, and solubility of HiFlow were similar to BC Sealer at 37 degrees C and 100 degrees C. HiFlow had significantly higher flow and radiopacity than BC Sealer at room temperature (P < .05), and when heated, HiFlow retained its higher flow and lower film thickness (P < .05). Both sealers showed decreasing viscosity with increasing shear rate, and at a shear rate of 0.01 and 0.1 s(-1), HiFlow exhibited lower viscosity than BC Sealer at all temperatures measured. The chemical composition of the 2 sealers was not changed by heating. Conclusions: HiFlow showed better performance on flow/viscosity and film thickness, especially under high temperatures, which are generated by the commonly used warm vertical compaction technique.
Introduction: The dentinogenesis potential of stem cells during dentin-pulp tissue regeneration may be compromised by microorganism components. Here we aimed to investigate the cell viability and osteo-/odontogenic differentiation of stem cells from apical papilla (SCAP) exposed to bacterial lipopolysaccharide (LPS) and to evaluate the molecular mechanism in vitro. Methods: CCK8 assay was used to assess the SCAP proliferation rate on exposure to different concentrations of LPS in medium. Dentin matrix protein-1 (DMP-1), runt-related transcription factor-2 (Runx-2), and alkaline phosphatase (ALP) expression and mineralized nodule formation were detected by Western blotting and alizarin red S staining to evaluate SCAP osteo-/odontogenic differentiation. Autophagosomes in SCAP and the autophagy-related markers Beclin 1, autophagy-related gene 5 (Atg5), and microtubule-associated proteins light chain 3 (LC3) were detected by transmission electron microscopy and Western blotting, respectively. Effects of the autophagy inhibitor 3-methyladenine on LPS-treated SCAP osteo-/odontogenic differentiation were also examined. Results: SCAP cell viability was decreased by 5 mg/mL LPS treatment on day 3. LPS (5 mg/mL) inhibited SCAP osteo-/odontogenic differentiation and decreased DMP-1, Runx-2, and ALP expression. Moreover, LC3, Atg5, and Beclin 1 expression and autophagosome number were elevated. Conversely, autophagy inhibition rescued the number of mineralized nodules and DMP-1, Runx-2, and ALP expression in the LPS-treated SCAP. Conclusions: Our findings indicated that autophagy was involved in the suppression of SCAP osteo-/odontogenic differentiation in an LPS-induced inflammatory environment. This study discloses autophagy modulation as a potential new strategy to improve SCAP osteo-/odontogenic differentiation in an inflammatory environment.
Introduction: The aim of this study was to investigate the cytobiological effects of platelet-rich fibrin (PRF) on stem cells from the apical papilla (SCAPs) in vitro and to further explore the underlying molecular mechanisms. Methods: SCAPs were isolated from immature third molars. Different concentrations of PRF conditioned medium (one eighth, one quarter, and one half PRF) were prepared. After pretreatment with PRF, the proliferation rate and migration capacity of SCAPs were examined by the Cell Counting Kit-8 assay and wound healing assay, respectively. Alizarin red S staining was performed to examine mineralized nodule formation. Western blot analysis was used to detect the expression of osteo-/odontogenic markers and the extracellular signal-regulated kinase (ERK) pathway in SCAPs. Data were analyzed by one-way analysis of variance. P values < .05 were considered statistically significant. Results: The Cell Counting Kit-8 assay showed that one eighth PRF improved the proliferation rate and the migration capacity of SCAPs (P < .005), whereas one quarter PRF and one half PRF showed no significant difference compared with the control group. The expression of osteo-/odontogenic markers and the capacity to form mineralized nodules of SCAPs were promoted by one eighth PRF and one quarter PRF. In addition, PRF activated ERK signaling, and the ERK inhibitor attenuated PRF-induced osteo-/odontogenesis of SCAPs. Conclusions: PRF improved the osteo-/odontogenic differentiation of SCAPs by activating the ERK pathway; meanwhile, PRF improved the proliferation and migration of SCAPs, and one eighth PRF achieved the most obvious promotion effect. The favorable cytobiological effects of PRF on SCAPs might serve as basis for PRF applications in regenerative endodontic treatment.
Introduction: The composition and relative abundance of bacterial species change throughout the development of dental caries; however, how these changes relate to clinical symptoms remains elusive. In this study, we explored the relationship between clinical symptoms and specific microorganisms in advanced dentinal caries. Methods: A total of 111 permanent premolars and molars were used to simulate the progression from caries to pulpitis indirectly. Clinical symptoms were evaluated, and teeth were diagnosed according to the diagnostic criteria of the American Association of Endodontics. Samples were collected for 16S ribosomal DNA sequencing. Associations between the microbiota and clinical symptoms/diagnosis and the relationship between alpha diversity and clinical symptoms/diagnosis were evaluated independently by the linear discriminant analysis effect size and Spearman rank correlation analyses. Results: The 16S ribosomal DNA sequences were assigned to 13,852 operational taxonomic units. The linear discriminant analysis effect size and Spearman correlations unveiled negative associations between the relative abundance of Bacteroidia and Gammaproteobacteria and referred pain, Gammaproteobacteria and the electric pulp test response, and Actinomyces and Propionibacterium and diagnosis (r < 0.0, P>.05). Conversely, the relative abundance of Lactobacillus was positively correlated to referred pain, the cold test, the percussion response, and diagnosis (r > 0, P > .05). Lactobillus reuteri, a probiotic bacterium, was more abundant in teeth with referred pain and teeth diagnosed with symptomatic irreversible pulpitis. The Spearman correlation between alpha diversity and clinical symptoms/diagnosis was not significant (P > .05). Conclusions: Clinical symptoms and diagnosis were significantly associated with specific microorganisms in the most advanced layers of dentinal caries.
Introduction: In late 2019, an outbreak of a new coronavirus named severe acute respiratory syndrome coronavirus 2 was detected in Wuhan, China. A great percentage of patients with this disease developed symptoms of dry cough, malaise, and a high fever. During this time, several patients requiring assessment and treatment of endodontic emergencies were directed to the School and Hospital of Stomatology at Wuhan University, Wuhan, China. We examined the characteristics of these patients. Methods: A total of 96 patients with a mean age of 42.24 6 18.32 years visited the general and emergency department of the School and Hospital of Stomatology at Wuhan University because of endodontic emergencies during the peak period of February 22 to March 2, 2020. Patient information was collected and organized by date of visit, sex, age, and systemic disease history. Body temperature was measured and acquired for each patient, a coronavirus disease 2019 (COVID-19) epidemiologic investigation questionnaire was given to each patient, an endodontic diagnosis was determined for the offending tooth, and a verbal numerical rating scale (VNRS) was used to record pain levels. Results: Of the total patient visits during this period, 50.26% of visits were for endodontic treatment. No patients had a fever (>37.2 degrees C). One patient with a confirmed COVID-19 history was admitted after recovery. Three admitted patients had been exposed to confirmed or suspected COVID-19 patients. Twelve admitted patients (12.5%) with a mean age of 62.426 13.77 years had a history of systemic diseases. The most common age group for endodontic emergencies was 45-64 years (30.21%), and patients of this group showed a significantly higher mean VNRS score compared with that of the 6- to 19-year age group and the 20- to 34-year age group (P<.05). The majority of endodontic emergency diagnoses were diseases of symptomatic irreversible pulpitis (53.10%). Patients who were diagnosed with symptomatic irreversible pulpitis, symptomatic apical periodontitis, and acute apical abscess showed a significantly higher mean VNRS score than that of other groups (P<.05). Conclusions: Endodontic emergencies, with symptomatic irreversible pulpitis being the most common, consist of a much higher proportion of dental emergencies in a COVID-19 high-risk area than normally. Vital pulp therapy can advantageously reduce treatment time, resulting in a reduced risk of infection for vital pulp cases. Rubber dams, personal protective equipment, and patient screening are of great importance during the COVID-19 outbreak in protecting clinicians.
Introduction: Nonsurgical endodontic retreatment and apical surgery are predictable procedures for the management of endodontically treated teeth with persistent disease. However, there is no information available that compares these treatment modalities based on patients' oral health-related quality of life (OHRQOL). The aims of this study were to compare the OHRQOL of patients who received nonsurgical endodontic retreatment versus those who received apical surgery and to identify correlations between OHRQOL, clinician-assessed healing outcome, and other factors. Methods: Patients who received treatment at 2 dental hospitals with a recall period of 6-24 months were invited to participate. They underwent follow-up examination and were surveyed with the Oral Health Impact Profile (OHIP-14). Healing outcomes were determined by clinical and radiographic evaluation. Potential influencing factors for OHIP-14 scores were investigated. Results: One hundred fifty patients (75 patients from each group) participated in the study. There were no differences in OHIP-14 scores between both groups at the follow-up. The overall adverse impact on OHRQOL was low, with patients experiencing greater impact in the domains of "physical pain" and "psychological discomfort." Women and patients who had preoperative pain reported a greater impact. There was an overall high healed and healing rate for both groups. No correlation was found between OHIP-14 scores and healing outcome. Conclusions: Patients who received nonsurgical endodontic retreatment and apical surgery reported comparable OHRQOL, with women and patients with preoperative pain reporting greater impact. Both treatments are viable options for the management of persistent endodontic disease based on clinician- and patient-reported outcome assessments.
Introduction: The antimicrobial peptide LL-37, in addition to its broad spectrum of antibacterial function, can promote odontogenesis and osteogenesis. Stem cells from the apical papilla (SCAPs) are essential for the formation of dentin/bonelike tissues. However, little information on these cells is available in regenerative endodontics. This study aimed to evaluate the effects of LL-37 on the proliferation, migration, and differentiation of SCAPs. Methods: SCAPs were isolated, cultured, and characterized. Cell viability was analyzed by Cell Counting Kit-8 assays (Dojindo, Kumamoto, Japan). Cell migration was investigated by transwell assays. Dentin sialophosphoprotein, dentin matrix protein 1, runt-related transcription factor 2, and osterix were assessed by quantitative polymerase chain reaction and Western blots. Alkaline phosphatase (ALP) activity and ALP staining were assessed to determine the in vitro potential for osteogenic differentiation. The involvement of the Akt/Wnt/beta-catenin signaling pathway was also studied. Results: In the 2.5-mu g/mL LL-37 -treated group, cell proliferation and migration were up-regulated. Quantitative polymerase chain reaction and Western blot assays both revealed that LL-37 at 2.5 mu g/mL up-regulated odonto/osteogenic markers (dentin sialophosphoprotein, dentin matrix protein 1, runt-related transcription factor 2, and osterix). LL-37 at 2.51 mu g/mL significantly promoted ALP activity and increased the staining in SCAPs. In addition, the p-Akt and p-glycogen synthase kinase-3 beta levels were increased in LL-37-treated SCAPs. The migratory and odonto/osteogenic differentiation capacities of SCAPs were inhibited after treatment with inhibitors LY294002 and XAV-939. Conclusions: Our study showed that LL-37 at 2.51 mu g/mL promoted the migration and odonto/osteogenic differentiation of SCAPs by activating the Akt/Wnt/beta-catenin signaling pathway.