[Comparison of the effects of using iRoot BP plus and MTA apical barrier surgery in young permanent teeth with chronic apical periodontitis].

PURPOSE: To explore the effect of using iRoot BP plus and MTA apical barrier surgery in young permanent teeth with chronic apical periodontitis. METHODS: A total of 122 patients with chronic periapical periodontitis with open root tips of permanent teeth were randomly divided into experimental group (n=61, 61 teeth) and a control group (n=61, 61 teeth). Patients in the experimental group received iRoot BP plus plus apical barrier surgery, while those in the control group received MTA apical barrier surgery. The old periapical index (O-PAI), apical transmission area, efficacy, treatment times, and inflammatory factor levels of the two groups of patients were compared at 3, 6, 9, and 12 months after surgery. SPSS 19.0 software package was used for statistical analysis. RESULTS: At 12 months after surgery, the O-PAI ratings of the experimental group and the control group were (1.48±0.36) and (1.71±0.42), respectively, and the apical transmission area was (0.51±0.14) and (1.09±0.31). There was a significant difference in the O-PAI ratings and apical transmission area between the two groups(P＜0.05). At 3 months, 6 months, and 12 months after surgery, the O-PAI scores of patients in both groups gradually decreased (P＜0.05). After 12 months of treatment, the success rates of the experimental group and the control group were 98.36% and 88.52%, respectively, with significant difference between the two groups (P＜0.05). The treatment frequency of patients in the experimental group and the control group was (3.64±0.58) times and (4.72±0.61) times, respectively, with a significant difference between the two groups(P＜0.05). After 3 months of treatment, the serum hs-CRP levels in the experimental group and the control group were (6.89±1.13) mg/L and (7.25±1.40) mg/L, respectively, with a significant difference compared to pre-treatment(P＜0.05). After 3 months of treatment, the serum IL-6 levels in the experimental group and the control group were (82.04±19.62) mg/L and (87.52±20.85) mg/L, respectively, with significant differences compared to pre-treatment (P＜0.05). There was no significant difference in serum IL-6 and hs-CRP levels between the two groups before and after treatment(P＞0.05). CONCLUSIONS: iRoot BP plus apical barrier surgery for the treatment of chronic apical periodontitis with open permanent teeth can reduce the O-PAI index, decrease the number of postoperative visits, and have a higher postoperative success rate.

Postoperative pain in oncological patients subjected to nonsurgical root canal treatment: a prospective case-control study.

OBJECTIVES: The purpose of this prospective study was to evaluate the incidence and intensity of postoperative pain in oncological patients with infected teeth subjected to nonsurgical root canal treatment or retreatment. METHODS: Teeth with apical periodontitis from healthy control patients and oncological patients (n = 70 per group) were root canal treated/retreated and evaluated for the development of postoperative pain. Patients from the two groups were matched for tooth type, gender, clinical manifestation of apical periodontitis, and intervention type. A visual analogue scale (VSA) was used to evaluate the incidence of postoperative pain at 24 h, 72 h, 7d, and 15d after chemomechanical procedures. Data were statistically analyzed for the incidence and intensity of postoperative pain in the two groups. RESULTS: Preoperative pain occurred in 10% of the individuals and in all these cases pain showed a reduction in intensity or was absent after endodontic intervention at 24-h evaluation. The overall incidence of postoperative pain at 24 h was 14% in oncology patients and 30% in controls (p = 0.03). At 72 h, the respective corresponding figures were 4% and 8.5% (p > 0.05). At 7 and 15 days, all patients were asymptomatic, irrespective of the group. CONCLUSIONS: No significant differences in postoperative pain were found between control and oncological patients. The low incidence of postoperative pain observed in both groups supports the routine use of nonsurgical root canal treatment/retreatment as valid options in oncological patients. CLINICAL RELEVANCE: Oncological patients had no increased risk of postoperative pain in comparison with control patients.

α-IRAK-4 Suppresses the Activation of RANK/RANKL Pathway on Macrophages Exposed to Endodontic Microorganisms.

Periapical lesions are common pathologies affecting the alveolar bone, often initiated by intraradicular lesions resulting from microbial exposure to dental pulp. These microorganisms trigger inflammatory and immune responses. When endodontic treatment fails to eliminate the infection, periapical lesions persist, leading to bone loss. The RANK/RANKL/OPG pathway plays a crucial role in both the formation and the destruction of the bone. In this study, the objective was to inhibit the RANK/RANKL pathway in vitro within exposed Thp-1 macrophages to endodontic microorganisms, specifically Enterococcus faecalis, which was isolated from root canals of 20 patients with endodontic secondary/persistent infection, symptomatic and asymptomatic, and utilizing an α-IRAK-4 inhibitor, we introduced endodontic microorganisms and/or lipoteichoic acid from Streptococcus spp. to cellular cultures in a culture plate, containing thp-1 cells and/or PBMC from patients with apical periodontitis. Subsequently, we assessed the percentages of RANK+, RANKL+, and OPG+ cells through flow cytometry and measured the levels of several inflammatory cytokines (IL-1ß, TNF-α, IL-6, IL-8, IL-10, and IL-12p70) in the cellular culture supernatant through a CBA kit and performed analysis by flow cytometry. A significant difference was observed in the percentages of RANK+RANKL+, OPG+ RANKL+ cells in thp-1 cells and PBMCs from patients with apical periodontitis. The findings revealed significant differences in the percentages of the evaluated cells, highlighting the novel role of the IRAK-4 inhibitor in addressing this oral pathology, apical periodontitis, where bone destruction is observed.

High-performing cross-dataset machine learning reveals robust microbiota alteration in secondary apical periodontitis.

Multiple research groups have consistently underscored the intricate interplay between the microbiome and apical periodontitis. However, the presence of variability in experimental design and quantitative assessment have added a layer of complexity, making it challenging to comprehensively assess the relationship. Through an unbiased methodological refinement analysis, we re-analyzed 4 microbiota studies including 120 apical samples from infected teeth (with/without root canal treatment), healthy teeth, using meta-analysis and machine learning. With high-performing machine-learning models, we discover disease signatures of related species and enriched metabolic pathways, expanded understanding of apical periodontitis with potential therapeutic implications. Our approach employs uniform computational tools across datasets to leverage statistical power and define a reproducible signal potentially linked to the development of secondary apical periodontitis (SAP).

Treatment strategy for patient with non-syndromic tooth agenesis: a case report and literature review.

BACKGROUND: Non-syndromic tooth agenesis (NSTA) is a type of ectodermal dysplasia (ED) in which patients with non-syndromic oligodontia may only affect teeth. No pathological findings were found in other tissues of the ectodermal. Herein, we report a case of a NSTA patient with severe dental anxiety and poor oral health. CASE PRESENTATION: A 5-year-old boy without systemic diseases presented as a patient with oligodontia, extensive caries, and periapical periodontitis. Molecular genetic analysis found a mutation in the Ectodysplasin A (EDA) gene, confirming the diagnosis of NSTA. CONCLUSION: Tooth agenesis (TA) is the most common ectodermal developmental abnormality in humans. Non-syndromic oligodontia patients often seek treatment in the department of stomatology. Because of their complex oral conditions, these patients should be provided with a systematic and personalized treatment plan.

Non-surgical treatment of maxillary lateral incisor double dens invaginatus type â ¢ with apical periodontitis.

Dental invagination is an abnormality of the crown or root development induced during tooth germ development when the enamel-forming apparatus or epithelial root sheath overpopulates and folds into the papilla. In severe cases, the invaginated channels are connected to the pulp and periodontal tissues, often causing endodontic and periapical diseases. The complex anatomical pattern of this disease adds difficulty in its preoperative diagnosis and clinical operation. In this paper, we report a case of non-surgical treatment assisted by cone beam CT and microscopy for maxillary lateral incisor double dens invaginatus type Ⅲ (Ⅲa and Ⅲb) with apical periapical infection. After 1-year follow-up, the affected tooth was asymptomatic and the periapical lesion was significantly reduced.

Is SWEEPS better than PUI in reducing intracanal bacteria and inflammation in cases of apical periodontitis?

To evaluate the efficacy of SWEEPS mode of the Er: YAG laser(SL) and passive ultrasonic irrigation(PUI) in the eradication of microorganisms and in the inflammation detection by IL-1ß. Thirty patients with chronic apical periodontitis(AP) were allocated into two groups: Group SL-SWEEPS laser activated irrigation(n = 15) and Group PUI-passive ultrasonic irrigation(n = 15). Bacteriological samples were taken before(S1) and after chemomechanical preparation(S2), and then after final irrigation activation(S3). The levels of total bacteria and Streptococci were measured by means of PCR. Blood samples were collected before and 3rd day after treatment. Enzyme-linked immunosorbent assay was used to measure the levels of IL-1ß. The bacterial reduction showed no differences between groups after chemo-mechanical treatment and after irrigant activation(p = 0.590). Post-treatment IL-1ß levels were lower than pretreatment levels in both groups(p < 0.001). SL or PUI application in addition to chemomechanical preparation has similar effects on total bacterial level and inflammation detected by IL-1ß in patients with AP.

Synthetic high-density lipoprotein (sHDL): a bioinspired nanotherapeutics for managing periapical bone inflammation.

Apical periodontitis (AP) is a dental-driven condition caused by pathogens and their toxins infecting the inner portion of the tooth (i.e., dental pulp tissue), resulting in inflammation and apical bone resorption affecting 50% of the worldwide population, with more than 15 million root canals performed annually in the United States. Current treatment involves cleaning and decontaminating the infected tissue with chemo-mechanical approaches and materials introduced years ago, such as calcium hydroxide, zinc oxide-eugenol, or even formalin products. Here, we present, for the first time, a nanotherapeutics based on using synthetic high-density lipoprotein (sHDL) as an innovative and safe strategy to manage dental bone inflammation. sHDL application in concentrations ranging from 25 µg to 100 µg/mL decreases nuclear factor Kappa B (NF-κB) activation promoted by an inflammatory stimulus (lipopolysaccharide, LPS). Moreover, sHDL at 500 µg/mL concentration markedly decreases in vitro osteoclastogenesis (P < 0.001), and inhibits IL-1α (P = 0.027), TNF-α (P = 0.004), and IL-6 (P < 0.001) production in an inflammatory state. Notably, sHDL strongly dampens the Toll-Like Receptor signaling pathway facing LPS stimulation, mainly by downregulating at least 3-fold the pro-inflammatory genes, such as Il1b, Il1a, Il6, Ptgs2, and Tnf. In vivo, the lipoprotein nanoparticle applied after NaOCl reduced bone resorption volume to (1.3 ± 0.05) mm3 and attenuated the inflammatory reaction after treatment to (1 090 ± 184) cells compared to non-treated animals that had (2.9 ± 0.6) mm3 (P = 0.012 3) and (2 443 ± 931) cells (P = 0.004), thus highlighting its promising clinical potential as an alternative therapeutic for managing dental bone inflammation.

Regenerative potential of mesoporous silica nanoparticles scaffold on dental pulp and root maturation in immature dog's teeth: a histologic and radiographic study.

OBJECTIVE: To evaluate histologically and radiographically the potential of dog's immature roots with apical periodontitis to regenerate after regenerative endodontic treatment using mesoporous silica nanoparticles (MSNs) with/without bone morphogenic protein (BMP-2) as scaffolds. METHODS: In 4 mongrel dogs, 56 immature teeth with 96 roots were infected, resulting in necrotic pulps and periapical pathosis. According to the evaluation time (Group I = 30 days and Group II = 90 days), 90 roots were divided into two equal groups (45 roots each) and 6 roots used to replace any lost root during the procedure. The two main groups were further divided according to treatment protocol into 5 subgroups (9 roots each): blood clot (BC subgroup), mesoporous silica nanoparticles scaffold only (MSNs subgroup), mesoporous silica nanoparticles impregnated with BMP2 (MSNs + BMP2 subgroup), infected teeth without treatment (+ ve control subgroup) and normal untouched teeth (-ve control subgroup). All teeth surfaces were coated with Tincture iodine and calcium hydroxide was applied prior to treatment protocols. Then, teeth were restored with glass ionomer filling to seal the remaining part of the access cavity. Radiography evaluation of the increase in root length, root thickness and occurrence of apical closure were performed. Following the sacrifice of the two dogs at each time of evaluation, histopathological analysis was performed and included the inflammatory cells count, bone resorption, tissue ingrowth, deposition of hard tissue, and closure of the apical part. All data were statistically analyzed. RESULTS: Compared to BC subgroup, MSNs and MSNs + BMP-2 subgroups exhibited significant higher increase in root length and thickness as well as higher vital tissue in-growth and new hard tissue formation in group II (P < 0.05). MSNs + BMP-2 subgroup had significant higher increase in root length and thickness as well as significant lower inflammatory cell count than MSNs subgroup in both groups (P < 0.05). There were no significant differences between MSNs and MSNs + BMP-2 subgroups regarding new hard tissue formation in both groups and apical closure in group I (P > 0.05). CONCLUSION: MSNs with/without BMP-2 scaffolds enabled the continuing growth of roots in immature teeth with necrotic pulps and periapical pathosis. Addition of BMP-2 to MSNs scaffold improved its outcome in regenerative endodontics. CLINICAL RELEVANCE: MSNs with/without BMP-2 scaffolds may alternate blood clot for regenerative endodontic treatment of immature teeth with necrotic pulps.

A 12-month randomized controlled trial to assess the efficacy of revitalization of retreated mature incisors with periapical radiolucency in adolescents.

The use of regenrative endodontics is restoring the health status of the root canals of retreated mature teeth is a novel approach. Therefore, the current trial aimed to compare the effectiveness of regenerative endodontic procedures (REPs) to non-surgical root canal retreatment (NS-RCR) in reducing periapical radiolucency over one year for the retreatment of mature incisors with periapical periodontitis. The secondary purpose was to assess clinical success and regain pulp sensibility. A parallel randomized controlled trial, 66 mature incisors with periapical radiolucencies were randomly divided into two equal groups and retreated with either REPs or NS-RCR. At baseline and after 6 and 12 months, teeth were assessed clinically and radiographically using a periapical index (PAI). The Mann-Whitney test was used to analyze nonparametric PAI scores. The Electric pulp test readings were analyzed using the repeated measure analysis of variance (ANOVA). Over the follow-up intervals, there was no significant intergroup difference in the PAI medians, the majority of the teeth displayed a reduction in periapical radiolucency. At the end of the follow-up period, the clinical successes for the REP and NS-RCR groups were 93.9% and 97%, respectively (p = 0.555). Positive pulp sensibility was recorded in 54.54% of cases in the REPs after 12 months. Both approaches showed a comparable diminishing of periapical radiolucencies and equivalent clinical results. A conventional, non-surgical endodontic retreatment may not always be necessary.

Optimal outcomes of pulpotomy in young patients: Long-term prospects for permanent molars with signs and symptoms indicative of irreversible pulpitis.

OBJECTIVES: Limited literature addresses the long-term success of complete pulpotomy in permanent molars with signs of irreversible pulpitis in young patients. The aim of this observational study was to prospectively evaluate the long-term outcomes of complete pulpotomy using mineral trioxide aggregate (MTA) over an average period exceeding 11 years. METHODS: Out of 27 molars displaying signs suggestive of irreversible pulpitis which underwent MTA pulpotomy, 24 molars were followed-up for a mean duration of 11.0 ± 2.2 years (range 8.2 to 14.8 years). Clinical and radiographic assessments were periodically conducted, tailored to each patient's specific circumstances. Treatment failure criteria included clinical signs and symptoms and radiographic evidence suggesting a lack of pulpal or periapical healing. RESULTS: 83 % of molars had signs and symptoms of symptomatic irreversible pulpitis, with 83 % displaying apical periodontitis. Clinically and radiographically, all pulpotomies (100 %) were considered successful. A hard tissue barrier was observed in 71 % of teeth, and continued root maturation was evident in all molars with open apices. Complete pulp canal obliteration (PCO) was present in 21 % of the molars. All radiographic apical radiolucencies completely resolved. CONCLUSIONS: This study demonstrates a 100 % success rate over an average 11-year follow-up for complete pulpotomy in managing permanent molars with signs and symptoms of irreversible pulpitis in young patients. It offers evidence for its long-term efficacy in promoting healing of pulp and periapical tissues. CLINICAL SIGNIFICANCE: This study showed high long-term success for complete pulpotomy in young permanent molars with irreversible pulpitis, with clinical and radiographic success over 11 years. Despite initial symptoms of pulpitis and apical periodontitis, the treatment resulted in tissue healing, root maturation, and resolution of periapical radiolucencies, suggesting it as an alternative to root canal therapy.

Apical periodontitis in endodontically-treated teeth: association between missed canals and quality of endodontic treatment in a Colombian sub-population. A cross-sectional study.

A high prevalence of post-treatment apical periodontitis associated to variables such as endodontic treatment quality and missed canals has been reported. AIM: The aim of this study was to evalúate the quality of endodontic treatment and the frequency of missed canals associated with teeth with apicalperiodontitis (AP) through CBCTin a Colombian sub-population. MATERIAL AND METHOD: This was a cross-sectional study assessing 318 cone beam computed tomography (CBCT) scans of endodontically treated teeth from Colombian individuals. The scans were taken using J Morita X550 (J Morita Corporation, Osaka, Japan), with voxel size 0.125 to 0.20 mm. All endodontically treated teeth were assessed for quality of treatment, presence of missed canals and AP. Allsamples were analyzed bytwo endodontics specialists and an radiology specialist. Chi-square or Fisher 's test and odds ratio were calculated to identify the association and risk relationship between the presence of AP and the study variables. RESULTS: Missed canals were found in 18.61% (86/462), and 95.3% were associated with AP. The frequency of AP was 62.34% (288/462) for all the evaluated teeth. AP was found in 27.43 % (79/288) of the teeth with adequate endodontic treatment, in contrast to 72.57% (209/288) of the teeth with inadequate treatment (P<0.01). The frequency of missed canals was highest in maxillary molars, with 55.23% (58/105), with 96.55% presenting AP. The second mesiobuccal canal wasthe most frequently missed canal, 88.52%o(54/61), with AP in 90.74% (49/54) of the cases. CONCLUSIÓN: There was a high frequency of teeth with missed canals and PA. More than half of the teeth with missed canals were maxillary molars, with MB2 being the most common canal, commonly presenting apical periodontitis.

Uma alta prevalência de periodontite apical pós-tratamento associada a variáveis como qualidade do tratamento endodôntico e fracasso do tratamento é relatada na literatura. O objetivo deste estudo foi avaliar a qualidade do tratamento endodôntico e a frequência e fracasso do tratamento associados a dentes com periodontite apical (PA) por meio de tomografia computadorizada de feixe cônico (TCFC) em uma subpopulação colombiana. MATERIAL E MÉTODO: Este foi um estudo transversal que avaliou 318 tomografias computadorizadas de dentes tratados endodonticamente de indivíduos colombianos. Os exames foram realizados utilizando o tomógrafo J Morita X550, com tamanho de voxel de 0,125 a 0,20 mm. Todos os dentes tratados endodonticamente foram avaliados quanto à qualidade do tratamento, presença de canais não localizados e AP. Todas as amostras foram avaliadas por dois especialistas em endodontia e um especialista em radiologia. Foram calculados o teste qui-quadrado ou de Fisher e a razão de chances para identificar associação e relação de risco entre a presença de PA e as variáveis do estudo. RESULTADOS: Foram encontrados canais não localizados em 18,61% (86/462) e 95,3% estavam associados à PA. A frequência de AP foi de 62,34% (288/462) para todos os dentes avaliados. AP foi encontrada em 27,43% (79/288) dos dentes com tratamento endodôntico adequado, em contraste com 72,57% (209/288) dos dentes com tratamento inadequado (P<0,01). A frequência de canais não localizados foi maior nos molares superiores, com 55,23% (58/105), sendo que 96,55% apresentavam PA. O canal mésio-palatino (MB2) apresentou maior frequência de canal não localizado (88,52% - 54/61), com PA em 90,74% (49/54) dos casos. CONCLUSÃO: Houve alta frequência de dentes com canais não localizados e com PA. Mais da metade dos dentes com canais não localizados eram molares superiores, sendo o MB2 é o canal com a maior frequência, comumente apresentando periodontite apical.

Regenerative Endodontic Procedure on an Immature Necrotic Molar: A Case Report with a 5-Year Review.

BACKGROUND The regenerative endodontic procedure (REP) for managing necrotic immature permanent teeth has the advantage of promoting root growth over the traditionally used apexification techniques. However, there is limited evidence on the long-term outcome of standardized REPs performed on immature molars. This case report presents the 5-year clinical and radiographic outcomes of REP performed on an immature mandibular first molar. CASE REPORT A healthy 7-year-old girl with a carious right mandibular first molar was referred to the endodontic clinic for evaluation and treatment. Clinical examination showed large occlusal caries, no tenderness to palpation and percussion tests, and no response to cold and electric pulp tests. Radiographic examination showed deep caries, apical radiolucency related to the open apices, and wide root canal space. Accordingly, the tooth was diagnosed with necrotic pulp and asymptomatic apical periodontitis. The REP was performed following the American Association of Endodontics guidelines, which comprise minimal instrumentation, disinfection with sodium hypochlorite irrigant, use of triple antibiotic paste, induced intracanal bleeding, and application of a coronal mineral trioxide aggregate plug. The patient missed the scheduled follow-up appointments but presented at the clinic 5 years later with an asymptomatic tooth. Clinical and radiographic examination revealed no tenderness to percussion and palpation test, no response to cold test, positive response to electric pulp test, apical healing, apical closure, root lengthening, and canal wall thickening and calcification. CONCLUSIONS While true pulp regeneration is unachievable, the REP, following the current protocol, is clinically successful in achieving root maturation and tooth retention.

The influence of intraoral cryotherapy on postoperative pain and substance P in symptomatic apical periodontitis: randomized clinical study.

Cryotherapy is widely utilized in medicine, particularly for pain management. This randomized clinical trial aimed to assess the effect of intraoral cold pack application (cryotherapy) on postoperative pain (POP) and the level of Substance P (SP) in patients with symptomatic apical periodontitis (SAP). Enrolled patients were randomly assigned to either cryotherapy or control group. After adequate anesthesia, access cavity, and biomechanical preparation of the root canal system were completed, the first apical fluid (AF) sample (S1) was obtained. A custom-made intraoral ice-gel pack was applied for 30 min in the cryotherapy group, while no intervention was performed in the control group. The second AF sample (S2) was collected 30 min later in both groups. Patients were asked to complete the Visual Analogue Scale (VAS) questionnaire to assess their POP. Quantification of SP in AF samples was performed using the enzyme-linked immunosorbent assay (ELISA) test. Data were analyzed statistically, revealing a significant reduction in POP and SP levels in the cryotherapy group compared to the control group (P ≤ 0.05). Furthermore, a moderate positive correlation was observed between SP levels and POP (P ≤ 0.05). In conclusion, intraoral cryotherapy represents a simple and cost-effective option for controlling POP and reducing inflammation levels in patients with SAP.

Is there any association between the presence of biomarkers and apical periodontitis? A systematic review.

This systematic review aimed to verify whether there is evidence of an association between apical periodontitis and the presence of systemic biomarkers. This study adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses - PRISMA. For this, the acronym PECO was used; population (P) of adult humans exposed (E) to the presence of apical periodontitis, compared (C) to adult humans without apical periodontitis, and the outcome (O) of the presence of biomarkers was observed. The articles were searched in PubMed, Scopus, Web of Science, LILACS, Cochrane Library, OpenGray, and Google Scholar grey databases. Subsequently, studies were excluded based on title, abstract, and full article reading, following the eligibility criteria. The methodological quality of the selected studies was evaluated using the Newcastle-Ottawa qualifier. After exclusion, 656 studies were identified, resulting in 17 final articles that were divided into case-control, cross-sectional, and cohort studies. Eight studies were considered to have a low risk of bias, one had a medium risk of bias, and eight had a high risk of bias. In addition, 12 articles evaluated biomarkers in blood plasma, four evaluated them in saliva, and only one evaluated them in gingival crevicular fluid. The results of these studies indicated an association between apical periodontitis and the systemic presence of biomarkers. These markers are mainly related to inflammation, such as interleukins IL-1, IL-2, and IL-6, oxidative markers, such as nitric oxide and superoxide anions, and immunoglobulins IgG and IgM. Systematic review registration: https://www.crd.york.ac.uk/prospero/, identifier (CRD42023493959).

Treatment of Retrograde Peri-Implantitis Originating From Apical Periodontitis of an Adjacent Tooth: A Clinical Case Letter.

This report aims to present a treatment of retrograde peri-implantitis originating from apical periodontitis of an adjacent tooth in an 84-year-old male. Apical periodontitis of the maxillary left central incisor (#9) extended to the apex of the maxillary left lateral incisor implant (#10), which had been functioning for 16 years. Root canal treatment for #9 was performed, followed by root end surgery to treat the apical periodontitis, which showed a periapical radiolucency measured 1 cm in its greatest dimension. After the root end filling was placed, neither bone substitute materials nor barrier membranes were used to fill and cover the bony defect area. A 2-year postoperative radiograph confirmed the osseous healing around the apices of #9 and #10.

The incidence and intensity of postoperative pain and Flare-up following the use of three different intracanal medicaments in teeth with posttreatment apical periodontitis: a randomized clinical trial.

OBJECTIVES: This randomized clinical trial aimed to compare the effect of intracanal medicaments on the incidence of postoperative pain and flare-up with posttreatment apical periodontitis (PTAP) of retreatment cases. MATERIALS AND METHODS: One hundred twenty patients diagnosed with PTAP with single-rooted teeth with single-canal without spontaneous pain or swellings were included and randomly divided into three groups according to the intracanal medicament used. Intracanal medicaments were placed into the root canals following the removal of previous root canal fillings and re-instrumentation. Calcium hydroxide (Ca (OH)2), chlorhexidine gel (CHX), calcium hydroxide and chlorhexidine gel combinations were used as intracanal medicaments. Postoperative pain scores were recorded at 6 and 12 h and 1, 2, 3, 4, 5, 6, and 7 days using a visual analog scale (VAS). Sensitivity on percussion, spontaneous pain, swelling, antibiotic and analgesic requirements of the patients were evaluated during clinical examinations performed postoperatively after 2 and 7 days. RESULTS: There were no statistically significant differences between groups in terms of VAS scores following the intracanal medicament application (p > 0.05). However, compared to the patients of 20-34 and 50-65 age groups, greater VAS scores were observed in patients of 35-49 age groups at 12 h, and 3, 4, 7 days (p < 0.05). Flare-up was observed in only one patient in the CHX gel group, and no flare-up was observed in other groups. CONCLUSIONS: Similar postoperative pain incidence in all experimental groups indicates that all three medicaments are clinically acceptable in inter-appointment management of retreatment cases in terms of post-endodontic pain and flare-up. CLINICAL RELEVANCE: In this randomized clinical trial, three different intracanal medicaments were utilized in nonsurgical endodontic retreatment and their effect on postoperative pain and flare-up incidence was examined. Thus, this study will be a significant contribution in the decision-making during clinical practice; since there are a limited number of prospective clinical trials in the literature about the severity of pain following retreatment procedures including intracanal medicament use.

Mitochondrial biogenesis disorder and oxidative damage promote refractory apical periodontitis in rat and human.

AIM: To elucidate whether mitochondrial biogenesis disorder and damage from oxidative stress promote refractory apical periodontitis (RAP) in rat and human. METHODOLOGY: Twenty Enterococcus faecalis-induced RAPs were established in the maxillary first molars of male Wistar rats. Concurrently, 12 periapical lesion specimens from patients presenting with RAP were obtained by apicoectomy. Radiographic examination and histologic analysis were conducted to evaluate periapical bone tissue destruction and morphological changes. The expression of key regulators of mitochondrial biogenesis, PGC-1α and Nrf2, were detected by immunohistochemistry and double immunofluorescence staining, Western blot and real-time PCR were also assayed. Mitochondrial ROS (mtROS) was identified by MitoSOX staining. Mitochondrial function was detected by the quantification of ATP production, mitochondrial DNA (mtDNA) copy number and activities of mitochondrial respiratory chain complexes. Furthermore, mitochondrial oxidative stress was evaluated by the determination of 3-nitrotyrosine (3-NT), 4-hydroxy-2-nonenal (4-HNE) and 8-hydroxy-deoxyguanosine (8-OHdG) expression levels, as well as malondialdehyde (MDA) expression and antioxidant capacity. Student's t-test was performed to determine significance between the groups; p < .05 was considered significant. RESULTS: In the maxilla, significantly more bone resorption, greater number of periapical apoptotic cells and Tartrate-resistant acid phosphatase (TRAP)-positive multinucleated cells were observed in the RAP group compared with the control group (p < .01). PGC-1α and Nrf2 were significantly reduced in rat and human RAP lesions compared to the control group (p < .01) at both the mRNA and protein levels. Double immunofluorescence analysis of PGC-1α or Nrf2 with TOMM20 also indicated that mitochondrial biogenesis was impaired in RAP group (p < .01). Additionally, mitochondrial dysfunction was observed in RAP group, as reflected by increased mtROS, decreased ATP production, reduced mtDNA copy number and complexes of the mitochondrial respiratory chain. Finally, the expression levels of mitochondrial oxidative stress markers, 3-NT, 4-HNE and 8-OHdG, were significantly increased in the RAP group (p < .01). Consistent with this, systemic oxidative damage was also present in the progression of RAP, including increased MDA expression and decreased antioxidant activity (p < .01). CONCLUSIONS: Mitochondrial biogenesis disorder and damage from oxidative stress contribute to the development of RAP.

Autophagy regulates bone loss via the RANKL/RANK/OPG axis in an experimental rat apical periodontitis model.

AIM: Autophagy is involved in human apical periodontitis (AP). However, it is not clear whether autophagy is protective or destructive in bone loss via the receptor activator of nuclear factor-κB ligand (RANKL)/RANK/osteoprotegerin (OPG) axis. This study aimed to investigate the involvement of autophagy via the RANKL/RANK/OPG axis during the development of AP in an experimental rat model. METHODOLOGY: Twenty-four female Sprague-Dawley rats were divided into control, experimental AP (EAP) + saline, and EAP + 3-methyladenine (An autophagy inhibitor, 3-MA) groups. The control group did not receive any treatment. The EAP + saline group and the EAP + 3-MA group received intraperitoneal injections of saline and 3-MA, respectively, starting 1 week after the pulp was exposed. Specimens were collected for microcomputed tomography (micro-CT) scanning, histological processing, and immunostaining to examine the expression of light chain 3 beta (LC3B), RANK, RANKL, and OPG. Data were analysed using one-way analysis of variance (p < .05). RESULTS: Micro-CT showed greater bone loss in the EAP + 3-MA group than in the EAP + saline group, indicated by an elevated trabecular space (Tb.Sp) (p < .05). Inflammatory cell infiltration was observed in the EAP + saline and EAP + 3-MA groups. Compared with EAP + saline group, the EAP + 3-MA group showed weaker expression of LC3B (p < .01) and OPG (p < .05), more intense expression of RANK (p < .01) and RANKL (p < .01), and a higher RANKL/OPG ratio (p < .05). CONCLUSION: Autophagy may exert a protective effect against AP by regulating the RANKL/RANK/OPG axis, thereby inhibiting excessive bone loss.

Milk-derived small extracellular vesicles inhibit the MAPK signaling pathway through CD36 in chronic apical periodontitis.

BACKGROUND: Small extracellular vesicles derived from milk (Milk-sEVs) have the advantages of easy availability, low cost, low toxicity, and inhibition of inflammation. CD36 mediates inflammation stress in a variety of disease states. The purpose of this study was to investigate the role of Milk-sEVs in inhibiting fibroblast inflammation through CD36 and provide reference data for the treatment of chronic apical periodontitis. RESULTS: The addition of Milk-sEVs resulted in decreased expression of inflammation-related factors in L929 cells, and transcriptome sequencing screened for the DEG CD36 in the Milk-sEV treatment group under inflammation. The mouse model of apical periodontitis was successfully established, and CD36 expression increased with the development of inflammation. Transfection of si-CD36 into L929 cells reduced inflammation by inhibiting activation of the MAPK signaling pathway. CONCLUSIONS: CD36 expression increased with the development of apical periodontitis. In the setting of LPS-mediated inflammation, Milk-sEVs inhibited activation of the MAPK signaling pathway by decreasing the expression of CD36 in L929 cells and thereby reducing inflammation.