Evaluation of the use of a clinical practice guideline for external apical root resorption among orthodontists.

BACKGROUND: External apical root resorption (EARR) is a frequently observed adverse event in patients undergoing fixed appliance therapy. Assessing the patients' risk during treatment is important, as certain factors are assumed to be associated with an increased likelihood of occurrence. However, their predictive value remains limited, making evidence-based clinical decision-making challenging for orthodontists. To address this issue, the Dutch Association of Orthodontists (NvVO) developed a clinical practice guideline (CPG) for EARR in accordance with the AGREE II instrument (Appraisal of Guidelines for Research and Evaluation II) in 2018. The aim of this study is to get insight into the actual utilization and the practical implementation of the guideline among orthodontists. The hypothesis to be tested was that after its introduction, clinical practice for EARR has changed towards the recommendations in the CPG. OBJECTIVE: To investigate the use of the 2018 clinical practice guidelines for EARR among orthodontists 3 years after its introduction. METHODS: A questionnaire using a 7-point Likert scale was developed concerning four domains of EARR described in the guideline. The questionnaire was piloted, finalised, and then distributed digitally among Dutch orthodontists. REDCap was used for data collection, starting with an invitation email in June 2021, followed by two reminders. Effect was tested by the Mann-Whitney U test, and the influence of demographic variables was analysed. RESULTS: Questionnaires were sent out to all 275 and completed by 133 (response rate 48%); N = 59 females and N = 73 males were included; 81% had their training in the Netherlands, 89% had ≥ 6 years of work experience, and 89% worked in private orthodontic practice. One hundred thirty orthodontists (98.5%) reported changes in clinical practice. The biggest positive change in clinical behaviour regarding EARR occurred if EARR was diagnosed during treatment. Sex, clinical experience, country of specialist training, and working environment of the respondents did not affect clinical practices regarding EARR. CONCLUSIONS: This questionnaire demonstrated that, 3 years after introduction of the guideline, orthodontists improved their self-reported clinical practices to a more standardised management of root resorption. None of the demographic predictors had a significant effect on the results.

Failed Regenerative Endodontic Case Treated by Modified Aspiration-irrigation Technique and Apexification.

AIM: This report addresses the management of a large persistent discharging lesion in an 11-year-old boy. The report describes the use of aspiration-irrigation technique for the management of immature necrotic tooth with persistent discharge after a failed regenerative procedure. BACKGROUND: Regenerative endodontics aim to provide an increase in root canal width, length, and in apical closure. Alternative procedures, such as apexification, should be attempted when regeneration fails. If the canal cannot be dried to persistent discharge, the aspiration-irrigation technique can be used. The technique relies on using aspiration along with irrigation to remove pus from the periapical area. CASE DESCRIPTION: This is a case for an 11-year-old patient who had trauma to tooth #11, which resulted in the complicated crown fracture. He had an emergency management that included pulpectomy and intracanal medication at another clinic. Two years later, the patient was presented to our clinic. Upon examination, the diagnosis was previously initiated therapy with asymptomatic apical periodontitis in immature tooth #11. Regeneration was attempted first but failed. The mineral trioxide aggregate (MTA) plug was removed, and the canal had persistent pus discharge. The canal was filled with intracanal medication, and then 2 weeks later, the canal was filled with triple antibiotic paste (TAP). Next visit, and due to continuous discharge, tooth #11 was treated conservatively with an intracanal aspiration-irrigation technique. An IrriFlex needle attached to a high-volume suction was used to aspirate the cystic fluid. Mineral trioxide aggregate plug apexification was performed in a later visit and the tooth was restored. CONCLUSION: During the 3-month and 16-month follow-up, there was resolution of the symptoms, a decrease in the periapical lesion size, and soft tissues appeared within normal limits. CLINICAL SIGNIFICANCE: Regenerative procedures are a good option for immature necrotic teeth. These procedures may fail due to persistent pus discharge from the root canals. The aspiration-irrigation technique is a good treatment option in cases of consciously discharging canals. How to cite this article: Alsofi L, Almarzouki S. Failed Regenerative Endodontic Case Treated by Modified Aspiration-irrigation Technique and Apexification. J Contemp Dent Pract 2024;25(1):92-97.

Platelet rich fibrin and MTA in the treatment of teeth with open apices.

BACKGROUND: The present study aimed to evaluate the effectiveness of using platelet-rich fibrin (PRF) as the apical matrix for the placement of MTA in nonsurgical endodontic therapy for teeth with periapical lesions and open apices. METHODS: Twelve teeth from eleven patients with periapical periodontitis and open apices were enrolled in the study. Nonsurgical endodontic therapy was performed with the PRF used as an apical barrier and the MTA manipulated as an apical plug for further thermoplasticized gutta percha in the remaining part of the root canal. Clinical signs and periapical digital radiographs were recorded and analyzed to evaluate the curing progress after periodical follow-ups of 1, 3, and 6 months. The horizontal dimension of the periapical lesion was determined, and the changes in the dimensions were recorded each time. The Friedman test was used for statistical analysis, with P < .05 serving as the threshold for determining statistical significance. RESULTS: All patients had no clinical symptoms after the first month of treatment, with a significant reduction in the periapical lesion after periodical appointments. CONCLUSIONS: PRF is an effective barrier when combined with MTA for the treatment of teeth with periapical periodontitis and open apices.

Allogeneic Bone Marrow Mesenchymal Stromal Cell Transplantation Induces Dentin Pulp Complex-like Formation in Immature Teeth with Pulp Necrosis and Apical Periodontitis.

INTRODUCTION: Dental pulp regeneration is challenging in endodontics. Cellular therapy is an alternative approach to induce dental pulp regeneration. Mesenchymal stromal cells (MSCs) have the capacity to induce dental pulp-like tissue formation. In this study, we evaluated the capacity of allogeneic bone marrow MSCs (BM-MSCs) to regenerate pulp following necrosis and apical periodontitis in children's permanent immature apex teeth. METHODS: Patients aged 8 to 12 years with pulp necrosis and apical periodontitis were evaluated. The study included 15 teeth (13 incisors and 2 molars) from 14 patients (8 boys and 6 girls). Radiographic evaluation showed periapical radiolucency and immature apex teeth. There was no response to cold or electric pulp testing. The root canal of each tooth was cleaned, shaped, and Ca(OH)2 used as an interappointment medication. Cryopreserved allogeneic BM-MSCs were thawed, expanded, incorporated into preclotted platelet-rich plasma, and implanted into the tooth's pulp cavity. They were sealed with bioceramic cement and composite. Sensibility, apical foramen, calcium deposits within the root canal, and resolution of periapical lesions were evaluated in each tooth over the following 12 months. RESULTS: Based on 9 variables established for dental pulp-like tissue regeneration, all MSC-treated teeth showed evidence of successful regeneration. Clinical and radiographic evaluation of the treated teeth showed periapical lesion healing, sensitivity to cold and electricity, decreased width of the apical foramen, and mineralization within the canal space. CONCLUSIONS: Transplantation of allogeneic MSCs induces the formation of dental pulp-like tissue in permanent immature apex teeth with pulp necrosis and apical periodontitis. Implant of MSCs constitutes a potential therapy in regenerative endodontics in pediatric dentistry. Future studies incorporating a larger sample size may confirm these results.

Influence of Embedding Medium on iPex Electronic Apex Locator Accuracy: An Ex Vivo Comparative Study Using Alginate, Saline, and Gelatin Models.

AIM: Accurate working length determination during root canal treatment is essential for achieving successful outcomes. This study aimed to evaluate the impact of embedding medium on the accuracy of iPex electronic apex locator (EAL). MATERIALS AND METHODS: Sixty-one extracted single-rooted teeth were decoronated and coronally flared with Gates-Glidden burs. Actual canal length (ACL) was obtained by introducing a size 8 K-file until its tip reached the most coronal border of the apical foramen. This step was performed thrice and then averaged. Deducting 0.5 mm from the ACL provided the working length (WL). The teeth were randomly placed in plastic containers filled with freshly mixed alginate, gelatin, or saline, with the lip clip placed in the medium. The blinded operator obtained electronic measurements using iPex by advancing a K-file with a size compatible with the canal attached to the file clip and advanced until the 0.0 mark, then withdrawn to the 0.5 mark. This step was performed thrice and then averaged. Data were analyzed using ANOVA and Tukey's post hoc test, with significance level set at 5% (α = 0.05). RESULTS: The mean difference between WL and iPex length obtained in the gelatin model was significantly longer than the difference with mean iPex length in alginate (p = 0.005) and in saline (p < 0.001). There was no significant difference between iPex readings obtained in alginate and saline (p = 0.249). CONCLUSION: The use of freshly mixed alginate or saline for ex vivo assessment of iPex is recommended, whereas the use of gelatin could increase the chances of readings longer than looked for. CLINICAL SIGNIFICANCE: Identifying the optimum embedding medium for ex vivo testing of EALs permits the comparison and assessment of several factors affecting EALs' precision under standardized conditions. This helps in understanding EAL performance in vivo and in optimizing its clinical utilization.

The capability of regenerative endodontics to promote the complete root formation in immature permanent teeth with different initial pre-operative conditions.

OBJECTIVES: To describe the potential possibility of complete root formation after regenerative endodontic procedures (REPs) in immature permanent teeth with different initial pre-operative conditions. MATERIALS AND METHODS: Children who underwent REPs in the Department of Pediatric Dentistry, Peking University School and Hospital of Stomatology, Beijing, China, from January 2013 to December 2022 were enrolled. Whether the tooth achieved complete root formation was determined using post-operative periapical radiography. The potential possibility of complete root formation after REPs in immature permanent teeth with different initial conditions is discussed. RESULTS: A total of 428 teeth from 401 patients were included, of which 258 (60.2%) achieved complete root formation. In cases that achieved complete root formation, the most serious type of trauma was avulsion, the teeth with the worst initial root development were less than one-third of the development (stages 6-7), and the longest duration of the presence of apical lesions in the tooth before the first visit was more than 180 days. There is a significant difference in the root formation of teeth with different initial developmental stages and diagnoses. CONCLUSIONS: The active period of continued root formation was 5-21 months post-operatively. The higher the initial stage of root development and the shorter the duration of the presence of apical lesions in the tooth before the first visit, the greater the possibility of root formation. However, complete root formation may still be expected after REPs in severely injured immature permanent teeth and teeth with poor initial pre-operative root development conditions (less than stage 7) at the first visit. This is also true for teeth with long-term and large-scale apical lesions.

Evaluating In Vitro Performance of a Novel Stainless Steel Rotary System (Gentlefile) Based on Debris Extrusion and Instrumentation Time.

The new Gentlefile (GF) system, made of stainless steel and developed by MedicNRG in Kibbutz Afikim, Israel, claims to have advantages over traditional nickel-titanium files. However, research has shown that nickel-titanium files are mechanically superior due to their increased flexibility, cutting efficiency, and ability to maintain canal anatomy with less risk of procedural errors. This study compared the amount of debris extrusion and the time required for root canal instrumentation using GF versus the nickel-titanium ProTaper Universal (PTU) system and a manual step-back (MSB) stainless steel technique. This in vitro experimental study utilized 66 extracted human single-canal mandibular premolars with mature apices and root curvature of less than 10 degrees. The teeth were randomly divided into three groups (n = 22) and standardized for working length before being placed in preweighed vials. Group 1 was instrumented with PTU, Group 2 with GF, and Group 3 with the MSB technique. Extruded debris was collected in the vials, dried in an incubator, and weighed using the same scale. The change in weight indicates the debris amount. Instrumentation time was recorded using a stopwatch. The normal distribution of data was assessed using the Kolmogorov-Smirnov test. The groups were then compared regarding the amount of extruded debris and instrumentation time using the Kruskal-Wallis test and one-way ANOVA, followed by the Games-Howell test, respectively (alpha = 0.05). No significant difference in apical debris extrusion was found among the three groups (P > 0.05). However, a significant difference in instrumentation time was detected between the groups (P < 0.05). MSB instrumentation took significantly longer than both the PTU (P = 0.001) and GF (P = 0.001) systems. The GF system did not demonstrate reduced apical debris extrusion or faster instrumentation time compared to PTU. MSB had the longest instrumentation time compared to the other techniques.

The Effect of Coronal Pre-flaring and Type of Root Canal Irrigation on Working Length Accuracy Using Electronic Apex Locators.

Background: Successful root canal treatment is influenced by the apical extent of root canal preparation and the eventual root canal filling. Achieving the full working length until the apical constriction, which is usually 0.5 - 1 mm shorter than the anatomical apex, is crucial. Electronic apex locators were used to detect the working length more accurately. There are six generations of electronic apex locators in the market. The selection of the appropriate irrigation with each apex locator for accurate working length determination is not fully investigated. Methods: The actual working lengths of 120 freshly extracted human single-rooted teeth were measured and compared with their working lengths using 3 rd generation (Root ZX) followed by 6 th generation (Raypex 6) apex locators in dry medium, presence of 5.25% sodium hypochlorite, and 2% chlorhexidine, without coronal pre-flaring and after coronal pre-flaring using the same irrigating media. Data were collected, tabulated, and afterward analyzed using one-way ANOVA with post-hoc to evaluate the significant difference in average working length between actual working length, Root ZX, and Raypex 6 apex locator working lengths accuracy. Results: The significant results were shown in roots that were coronally pre-flared and their working lengths were measured in a dry medium using Raypex 6 apex locator. While using the Root ZX apex locator, the most accurate results were shown in roots that were coronally pre-flared and their working lengths were measured while using a chlorhexidine irrigating solution. Conclusions: It is concluded that it is very important to know the specific irrigating medium to be used with each specific electronic apex locator to achieve the most accurate working length results.

Evaluation of accuracy of an electronic apex locator in presence of sodium hypochlorite in primary teeth with and without resorption.

This study compared the accuracy of Root ZX mini apex locator in presence of sodium hypochlorite (NaOCl) in primary molars with and without apical resorption. Sixty-four extracted primary lower molar teeth with 32 root resorption and 32 without resorption were selected. To determine the actual working length (AWL), a K-file was inserted into the root canal until the tip of the file was visible at the major foramen or the resolution level. It was then withdrawn 1 mm. This value was recorded as AWL. The teeth were then divided subgroups (with/without NaOCl). To determine the electronic working length, a Root ZX mini apex locator in canals with/without NaOCl was used. A K-file was inserted into the canal to just beyond the foramen, as indicated by the flashing "APEX" bar, and the electronic working length was determined by subtracting 1 mm from this length. The deviation of the Root ZX mini measurement from the AWL was determined. Student's t-test was used for statistical analysis. In teeth with no resorption, the measurement accuracy rates (within+/-0.5 mm) of non-NaOCl and NaOCl groups were 84.37% and 81.25%, respectively (p > 0.05); within+/-1 mm, the non-NaOCl and NaOCl demonstrated 100% and 96.87% accuracy, respectively (p > 0.05). In teeth with resorption, the measurement accuracy rates (within+/-0.5 mm) was 81.25% for the non-NaOCl and 62.50% for the NaOCl, respectively (p < 0.05). The measurement accuracy rates (within+/-1 mm) of the non-NaOCl and NaOCl was 96.87% and 84.37%, respectively (p < 0.05). The presence of NaOCl in the root canal affected the accuracy of the Root ZX mini in primary teeth with apical resorption, but not in teeth without resorption.

Measurement of the apical anatomy of immature maxillary central incisors using cone-beam computed tomography.

OBJECTIVE: To investigate the CBCT findings of the apical anatomy of immature maxillary central incisors. METHODS: CBCT images of 100 immature maxillary central incisors in Nolla 8 and 100 immature maxillary central incisors in Nolla 9 were collected. The mesiodistal and carniocaudal diameters of the apical foramen of immature maxillary central incisors were measured by software included with CBCT, as well as the mesiodistal, carniocaudal and facioligual diameters of the apical shadow. The apical shadow and apical foramen diameters were compared between Nolla 8 and Nolla 9. Data were analyzed using the MedCalc software package. RESULTS: For immature maxillary central incisors, the mesiodistal and facioligual diameters of the apical foramen were 2.75±0.68 mm and 3.28±0.74 mm in Nolla 8 and 1.50±0.51 mm and 1.92±0.79 mm in Nolla 9. The mesiodistal, facioligual and carniocaudal diameters of the apical shadow were 3.84±0.73 mm, 4.49±0.68 mm and 3.41±1.27 mm in Nolla 8 and 2.76±0.60 mm, 3.41±0.80 mm and 2.06±0.65 mm in Nolla 9, respectively. CONCLUSIONS: The immature maxillary central incisors in Nolla 8 have a larger apical shadow and apical foramen than those in Nolla 9. The apical region of the maxillary central incisors in Nolla 8 was more likely to have a broad, blurred lamina dura. With the development of the apical foramen, the lamina dura in the apical region tended to be clear and sharp. CLINICAL SIGNIFICANCE: To our knowledge, this is the first study to radiologically analyse the in vivo anatomy of the apical foramen and apical shadow of immature maxillary central incisors. The results of this study provide a more detailed understanding of the apical anatomy of the immature maxillary central incisor for the diagnosis and treatment of apical lesions.

Shaping outcomes of Reciproc Blue and Rotate in roots canals with band-shaped isthmuses: micro-CT study.

OBJECTIVE: This study assessed the outcome of shaping the mesial roots of mandibular first molars containing band-shaped isthmuses with an isthmus floor located at the apical third with Reciproc Blue and Rotate instruments in terms of canal transportation, canal aberrations and unprepared apical canals. MATERIALS AND METHODS: Pair-matched mesial roots of mandibular first molars according to their isthmus location (distance from apical foramina) and size were constructed based on quantitative measurements (length, major and minor diameter at isthmus roof and floor) on preoperative micro-CT scanning (n = 10). The pair-matched specimens were prepared either using Reciproc Blue R25 (25.08v) or Rotate (15.04, 20.05, 25.06) instruments and then subjected to a second micro-CT scanning. Micro-CT scans were analysed to evaluate the canal transportation at the apical foramen and isthmus floor levels and the frequency of procedural errors (separated instruments, artificial canal preparation, cross shaping and unprepared apical canals). Canal transportation values were compared using Mann-Whitney U, and the distribution of procedural errors was compared with chi-square tests with a 5% significance threshold. RESULTS: Greater transportation values were detected in the apical foramen level compared to the isthmus floor in both groups. No significant difference was detected between Rotate and Reciproc Blue groups in terms of absolute transportation values and the incidence of procedural errors (p > .05). CONCLUSION: Preparation of mesial root canals containing a band-shaped isthmus at the apical portion with Reciproc Blue and Rotate instruments caused transportation of the original canal position at the isthmus floor and the apical foramen levels and resulted in procedural errors. CLINICAL RELEVANCE: This ex vivo micro-CT study using controlled pair-matched specimens showed that presence of a band-shaped isthmus complicates canal preparation procedure irrespective of the preparation systems.

Comparison of Efficacy of Lidocaine and Articaine as Inferior Alveolar Nerve Blocking Agents in Patients with Symptomatic Irreversible Pulpitis: Randomized Controlled Trial.

Background and Objectives: Lidocaine Hydrochloride has been the standard choice for local anesthesia in dentistry and Articaine's unique structure and growing popularity make it a viable alternative. Due to contradictory results in prior research and a scarcity of trials conducted in the Pakistani population, this study aims to compare the anesthetic efficacy of Lidocaine with Articaine for inferior alveolar nerve blocks in patients with symptomatic irreversible pulpitis. Materials and Methods: This double-blinded, randomized controlled trial included 152 patients who were selected by consecutive non-probability sampling. The participants included patients who presented with symptomatic irreversible pulpitis in mandibular posterior teeth (molars and premolars) and depicted normal apical tissue radiographically. The patients were equally and randomly divided into two groups. The control group received 2% Lidocaine Hydrochloride injections, and the experiment group received 4% Articaine Hydrochloride injections. Participants scored their pain on the HP-VAS both before and after the administration of anesthesia. A value of 54 mm or less on the scale indicated effective anesthesia. The data obtained were analyzed using SPSS. Chi-square test was applied to analyze data for statistical significance. Results: There was no statistically significant difference in the efficacy of the two anesthetic agents. During access cavity preparation, Lidocaine demonstrated a success rate of 93%, whereas Articaine exhibited a slightly higher success rate of 97%. During initial instrumentation, the success rates for Lidocaine and Articaine were 72% and 71%, respectively. This suggests that both Lidocaine and Articaine were effective in achieving anesthesia during the dental procedure in patients with symptomatic irreversible pulpitis, with Articaine showing a slightly better success rate, although the difference was not statistically significant. Conclusions: The anesthetic efficacy of Articaine is similar to that of lidocaine in subjects with symptomatic irreversible pulpitis. Hence, Articaine can serve as an alternative to Lidocaine for local anesthesia administration in dentistry.

[Effects and mechanism of glycine on rat cardiomyocytes pretreated with serum from burned rats].

Objective: To investigate the effect and mechanism of glycine on rat cardiomyocytes pretreated with serum from burned rats (hereinafter referred to as burn serum). Methods: Experimental research methods were adopted. Thirty gender equally balanced Wistar rats aged 7 to 8 weeks were collected, 10 of which were used to prepare normal rat serum (hereinafter referred to as normal serum), and the other 20 were inflicted with full-thickness burn of 30% total body surface area to prepare burn serum. Primary cardiomyocytes were isolated and cultured from the apical tissue of 180 Wistar rats aged 1 to 3 days by either gender for follow-up experiments. Cells were divided into normal serum group and burn serum group treated with corresponding serum according to the random number table (the same grouping method below). Trypanosoma blue staining was performed at post treatment hour (PTH) 1, 3, 6, 9, and 12 to detect the cell survival rate. Cells were divided into burn serum alone group treated with burn serum for 6 h followed by routine culture of 30 min and 0.4 mmol/L glycine group, 0.8 mmol/L glycine group, 1.2 mmol/L glycine group, 1.6 mmol/L glycine group, and 2.0 mmol/L glycine group treated with burn serum for 6 h followed by culture of 30 min with corresponding final molarity of glycine, i.e., at post intervention hour (PIH) 6.5, the cell survival rate was detected as before. Cells were divided into normal serum group, burn serum alone group, 0.8 mmol/L glycine group, 1.2 mmol/L glycine group, and 1.6 mmol/L glycine group, with the same intervention of 6.5 h as before, respectively. The content of adenosine monophosphate (AMP) and adenosine triphosphate (ATP) was detected by high performance liquid chromatography, and the AMP/ATP ratio was calculated. The protein expressions of phosphorylated mammalian target of rapamycin complex 1 (p-mTORC1), phosphorylated p70 ribosomal protein S6 kinase (p-p70 S6K), phosphorylated eukaryotic translation initiation factor 4E-binding protein 1 (p-4E-BP1), and phosphorylated AMP-activated protein kinase (p-AMPK) were detected by Western blotting. Cells were divided into normal serum group, burn serum alone group, 0.8 mmol/L glycine group intervened as before and 0.8 mmol/L glycine+25 ng/mL rapamycin group treated with burn serum followed by culture with two reagents. The expressions of heat shock protein 70 (HSP70), metallothionein (MT), and tubulin were detected by immunofluorescence method after 30 min of corresponding culture at PTH 1, 3, and 6, i.e., at PIH 1.5, 3.5, and 6.5, and the microtubule morphology was observed at PIH 6.5. The sample number at each time point was 10. Data were statistically analyzed with analysis of variance for factorial design, one-way analysis of variance, least significant difference (LSD)-t test, LSD test, and Bonferroni correction. Results: At PTH 1, 3, 6, 9, and 12, the cell survival rates in burn serum group were significantly lower than those in normal serum group (with t values of 4.96, 16.83, 35.51, 34.33, and 27.88, P<0.05). In burn serum group, the cell survival rate at PTH 3, 6, 9, or 12 was significantly lower than that at PTH 1 (P<0.05), the cell survival rate at PTH 6, 9, or 12 was significantly lower than that at PTH 3 (P<0.05), and the cell survival rate at PTH 6 was similar to that at PTH 9 (P>0.05) but significantly higher than that at PTH 12 (P<0.05). Treatment of 6 h was selected as the follow-up intervention time of burn serum. At PIH 6.5, compared with that in burn serum alone group, the cell survival rate in each glycine group was significantly increased (P<0.05). The cell survival rate in 0.8 mmol/L glycine group was the highest, and 0.8, 1.2, and 1.6 mmol/L were selected as subsequent glycine intervention concentrations. At PIH 6.5, the AMP/ATP ratio of cells in burn serum alone group was significantly higher than that in normal serum group, 1.2 mmol/L glycine group, or 1.6 mmol/L glycine group (P values all <0.05), and the AMP/ATP ratio of cells in 1.6 mmol/L glycine group was significantly lower than that in 0.8 mmol/L glycine group (P<0.05). At PIH 6.5, the protein expressions of p-mTORC1, p-p70 S6K, and p-4E-BP1 of cells in normal serum group, burn serum alone group, 0.8 mmol/L glycine group, 1.2 mmol/L glycine group, and 1.6 mmol/L glycine group were 1.001±0.037, 0.368±0.020, 1.153±0.019, 1.128±0.062, 1.028±0.037, 0.96±0.07, 0.63±0.12, 1.17±0.13, 1.13±0.16, 1.11±0.11, and 0.98±0.06, 0.45±0.08, 1.13±0.05, 0.77±0.12, 0.51±0.13. Compared with those in burn serum alone group, the protein expressions of p-mTORC1, p-p70 S6K, and p-4E-BP1 of cells in normal serum group and each glycine group were significantly increased (P<0.05), while the protein expressions of p-AMPK were significantly decreased (P<0.05). Compared with those in 0.8 mmol/L glycine group, the protein expression of p-4E-BP1 of cells in 1.2 mmol/L glycine group and the protein expressions of p-mTORC1 and p-4E-BP1 of cells in 1.6 mmol/L glycine group were significantly decreased (P<0.05). Compared with those in 1.2 mmol/L glycine group, the protein expressions of p-mTORC1 and p-4E-BP1 of cells in 1.6 mmol/L glycine group were significantly decreased (P<0.05), while the protein expression of p-AMPK was significantly increased (P<0.05). Compared with those in normal serum group, the expression of tubulin of cells in burn serum alone group was significantly decreased at PIH 1.5, 3.5, and 6.5 (P<0.05), while the expression of HSP70 of cells at PIH 1.5 and 3.5 and the expression of MT at PIH 3.5 and 6.5 were significantly increased (P<0.05). The expressions of HSP70 and MT of cells at PIH 1.5, 3.5, and 6.5 and the expression of tubulin at PIH 1.5 and 3.5 in burn serum alone group and 0.8 mmol/L glycine+25 ng/mL rapamycin group were significantly lower than those in 0.8 mmol/L glycine group (P<0.05). At PIH 6.5, compared with that in normal serum group, the cell microtubule structure in burn serum alone group was disordered; the cell boundary in 0.8 mmol/L glycine group was clearer than that in burn serum alone group, and the microtubule structure arranged neatly near the nucleus. Compared with that in 0.8 mmol/L glycine group, 0.8 mmol/L glycine+25 ng/mL rapamycin group had unclear cell boundaries and disordered microtubule structure. Conclusions: Burn serum can cause cardiomyocytes damage in rats. Glycine can significantly up-regulate mammalian target of rapamycin/p70 ribosomal protein S6 kinase/eukaryotic translation initiation factor 4E-binding protein 1 signaling pathway through AMP-activated protein kinase, promote the synthesis of protective proteins HSP70, MT, and tubulin, stabilize the microtubule structure, and exert cardiomyocytes protection function.

The difference distance between the apical foramen and the anatomical apex in primary teeth-An in vitro study.

INTRODUCTION: The apex area in the primary teeth changes continuously due to the physiologic resorption, therefore; the apical foramen (AF) may not correspond to the anatomic apex (AA), which gives a big challenge to achieve successful endodontic treatment. The aim of this research was to study the difference distance (DD) between the position of the AA and AF, besides the difference acceptance (DA) in primary teeth, and the effect of the following variables: root canal curvature, resorption degree, and canal size on DD and DA separately. METHODS: In this research, 180 root canals from 60 primary teeth were studied. Two lengths of each canal were measured by a K-file from a certain point in the crown; the first length was until the AA and the second was until the AF. Then DD was obtained by calculating the difference between those two lengths. Statistical analysis tests were done. A p value of <.05 was considered significant at a 95% confidence level. RESULTS: The percentage of canals with 0 mm DD was 34.4%, while it was 1.1% with DD of 6 mm. The percentages of acceptable ( ≤ 2 mm) and unacceptable ( > 2 mm) difference were 84.4% and 15.6%, respectively. There was a significant difference in the DD value between the three groups of curvature degree and the three groups of canal size. There was a significant difference between the DA in the three groups of canal size. CONCLUSION: DD has a wide variation value in primary teeth regardless of the degree of root resorption, which has not affected this value or the accepted difference; however, DD and acceptable difference values are somehow affected by the degree of root curvature and canal size. We recommend adding acceptable difference as a criterion when considering pulpectomy treatment in primary teeth.

Apical extrusion of debris when using OneCurve, ProTaper Next and TruNatomy in curved canals.

BACKGROUND: The extrusion of apical debris is related to various factors, and may be affected by variations in technique or instrumentation system. Although the extrusion cannot be completely prevented, it is crucial to minimize the amount of extruded material. OBJECTIVES: The present study aimed to compare apical debris extrusion by the novel TruNatomy (TRN), OneCurve (OC) and ProTaper Next (PTN) instruments in curved root canals. MATERIAL AND METHODS: A total of 60 multi-rooted human mandibular molar teeth with moderate and severe curvature were selected and randomly divided into 3 groups. The root canals were prepared with the OC, TRN and PTN files. For collecting the debris extruded through the apical foramen, Eppendorf tubes were used. After the vaporizing period, the tubes were re-weighed, and the amount of the extruded debris was calculated by subtracting the initial weight from the final weight. Statistical analysis was performed with the Shapiro-Wilk and Kruskal-Wallis tests. The statistical significance level was set at p < 0.05. RESULTS: The least amount of debris was extruded with TRN and the greatest with PTN, but the difference between the groups was not significant (p = 0.257). CONCLUSIONS: All instrumentation systems were associated with debris extrusion. The tested file systems presented similar results in terms of apical debris extrusion in curved canals. The novel TRN system demonstrated promising results, comparable to OC and PTN.

An Innovative Technique for Ejaculation-Sparing Prostatic Enucleation with Thulium:YAG Laser.

Purpose: We report our experience with 100 patients who underwent an innovative prostate enucleation technique that spares the complete urethral-plate from the veru montanum to the bladder neck using a low-energy thulium laser emission. The aim of our study was to evaluate the short-term effects of this procedure on ejaculation preservation and urinary obstruction. Materials and Methods: The International Prostate Symptom Index (IPSS), quality of life (QoL), and Male Sexual Health Questionnaire Ejaculatory Dysfunction (MSHQ-EJD) Short Form were used as validated instruments to quantify ejaculatory dysfunction before and 6 months after the surgery. Results: The median IPSS score pre- and postoperatively was 20 and 5, respectively (p < 0.0001); QoL dropped from a median of 4-1 (p < 0.0001); and the mean preoperative maximal flow rate improved significantly (8.5 vs 21.2 mL/min) (p < 0.0001). Furthermore, there was significant reduction in postvoid residual postoperatively (p < 0.0001). Postoperative ejaculatory function was preserved in 92/100 patients (92%). According to the MSHQ-EJD score, patients reported a slight nonsignificant decrease in frequency of ejaculation (item 1), force of expulsion (item 2) and reduction in semen volume during ejaculation (item 3), with the exception of ejaculation discomfort (item 4). Conclusion: According to our results, complete removal of the apical tissue, which has been advocated as an integral part of the so called ejaculatory hood, does not interfere with ejaculation if the ventral lissosphincter remains intact.

In Vitro Comparison of the Accuracy of Cone-Beam Computed Tomography Scanning and Electronic Apex Locators in Detection of Simulated Root Perforations in Different Localizations.

INTRODUCTION: This study aimed to compare the accuracy of cone-beam computed tomographic (CBCT) scanning and 2 different electronic apex locators (EALs) in the detection of simulated root canal perforations in different localizations. METHODS: Eighty human mandibular premolars were prepared and divided into 2 groups according to the localization of the perforation area, having a 1-mm diameter. The distance between the occlusal edge and the beginning of the perforation was measured under a stereomicroscope (actual working length) using 2 EALs (Propex II [Dentsply Maillefer, Ballaigues, Switzerland] and Dentaport ZX [J. Morita, Tokyo, Japan]) (electronic working length) and CBCT images (CBCT working length). The calculations were made by subtracting the actual working length from the electronic working length and the CBCT working length to determine the differences. RESULTS: In the apical third perforation group, there was a significant difference between Dentaport ZX and CBCT imaging. There was no significant difference between Dentaport ZX and Propex II and Propex II and CBCT measurements. In the middle third perforation group, Propex II was significantly more successful than CBCT imaging. In addition, there was no significance between the accuracy of Propex II in detecting the perforation area between the apical third perforation group and the middle third perforation group. CBCT imaging was more accurate in detecting the perforation area in the apical third perforation group than in the middle third perforation group. CONCLUSIONS: In cases in which the root canal perforation was in the apical third of the root, both the EAL and CBCT imaging were successful in determining the perforation area, whereas the success rate of all devices used in this study decreased when the perforation area was in the middle third of the root.

Apexification Outcomes in the United States: A Retrospective Cohort Study.

INTRODUCTION: This epidemiological analysis used procedure codes from dental insurance claims data to identify apexification cases and evaluate survival at the tooth-level. METHODS: Dental insurance claims data from New York State (2006-2019) and Massachusetts (2013-2018) were used in an observational, retrospective cohort study to evaluate the provision and treatment outcomes of apexification. Statistical analyses included Kaplan-Meier survival estimates and Cox proportional hazards regression. Cox proportional hazard regression was used to evaluate the hazard of adverse event occurrence by age, gender, tooth type, placement of permanent restoration, and dental provider type. A sensitivity analysis evaluated potential bias in the survival estimates and adjusted hazard ratios (aHRs) due to differential loss to follow-up. Robust standard errors were used to account for potential dependence between teeth within an individual. RESULTS: The analytic cohort of 575 individuals included 632 teeth, with an average follow-up time of 64 months. The survival rates of apexification procedures were 95% at 1 year; 93% at 2 years; 90% at 3 years; and 86% at 5 years. Tooth retention following apexification was 98% at 1 year; 96% at 2 years; 95% at 3 years; and 90% at 5 years. Tooth type and subsequent placement of a permanent restoration were significant predictors of survival after apexification. CONCLUSIONS: The procedural and tooth survival outcomes of apexification were high and comparable to studies that analyzed clinical data on tooth survival following apexification.

Comparative Evaluation of Apically Extruded Debris During Root Canal Preparation Using Three Different File Systems Applied Under 2.5% Sodium Hypochlorite or 2% CHX Irrigation.

The chemomechanical cleaning of the root canal system is performed using manual and rotary files. This study aimed to compare the effect of ProTaper, Reciproc and HyFlex rotary files considering 2.5% sodium hypochlorite and 2% chlorhexidine (CHX) as irrigating solutions on apical extrusion of intracanal debris. Single-canal mandibular premolars (N=165) were evaluated. The teeth were divided into 6 experimental groups (N=25) for root canal instrumentation using 3 file systems, (Reciproc, HyFlex and ProTaper) and two irrigation solutions, namely 2.5% sodium hypochlorite or 2% CHX. Fifteen teeth were also assigned into three control groups (n=5) with saline as irrigation solution. Eppendorf tubes were weighed and the teeth were placed inside. The canals were instrumented and the tubes weighed to determine the dry weight of extruded debris. Data were analyzed using one-way ANOVA and Bonferroni test (α=0.05). The mean amount of extruded debris using the sodium hypochlorite solution was significantly higher than other irrigating solutions (p⟨0.001). The mean amount of extruded debris using the Reciproc file system was significantly higher compared to ProTaper and HyFlex (p⟨0.001). The use of the sodium hypochlorite solution, single-file systems and reciprocal movement are associated with higher debris extrusion and might be associated with higher risk of postoperative pain.

Evaluating the efficacy of endodontic microsurgery for teeth with an undeveloped root apex and periapical periodontitis after nonsurgical treatment failure.

AIM: To determine the efficacy of endodontic microsurgery for teeth with an undeveloped root apex and periapical periodontitis caused by an abnormal central cusp fracture after failed nonsurgical treatment. METHODOLOGY: Eighty teeth in 78 patients were subjected to endodontic microsurgery. All patients were clinically and radiologically examined 1 year postoperatively. The data were statistically analyzed using SPSS 27.0 software. RESULTS: Of the 80 teeth in 78 patients, periapical lesions had disappeared in 77 teeth at 1-year postoperative follow-up, with a success rate of approximately 96.3% (77/80). The efficacy of endodontic microsurgery was not affected by sex, age, extent of periapical lesions, and presence of the sinus tract. Between-group differences were not statistically significant (P > 0.05). CONCLUSIONS: Endodontic microsurgery can be an effective alternative treatment option for teeth with an undeveloped root apex and periapical periodontitis caused by an abnormal central cusp fracture after nonsurgical treatment failure.