Search Results (54)

Background/Objectives: The removal of a fiber post (FP) during endodontic retreatment can be the source of significant complications. This study evaluated two commonly used techniques in removing a fiber post from an endodontically treated tooth by investigating three metrics: volume of dentin removed, efficiency, and temperature increase. Methods: Thirty extracted, single-rooted teeth were decoronated at the CEJ, then underwent endodontic treatment and post-space preparation. Fiber posts were bonded within the canal space. Teeth were pair-matched and randomly assigned to undergo post removal via Munce bur (MB) or diamond-coated ultrasonic tip (US). Teeth were scanned with micro-CT prior to post placement and after post removal. Results: The volume of dentin removal was not statistically significant between groups (p > 0.05), but the Munce bur resulted in eccentric removal patterns. There was a statistically significant difference in the time required to remove the fiber post between MB and US (p < 0.05). Removal of a fiber post with a Munce bur took an average of 58 s. Removal of a fiber post with an ultrasonic tip took an average of 502 s. There was no statistically significant difference in maximum temperature generated during post removal between MB and US (p > 0.05). Conclusions: Removal of a FP with a Munce bur requires significantly less time when compared to using an ultrasonic tip, with reduced risk of generating excessive heat for either technique with adequate coolant. US can stay more centered in the canal during FP removal when compared to Munce burs, potentially reducing unfavorable outcomes. Full article

This study compared the efficacy of different solutions in achieving patency in teeth filled with AH Plus Bioceramic sealer. Eighty-five premolars with a straight canal were prepared. After sealer placement, a master gutta-percha cone was introduced 2 mm short of the working length. The teeth were stored at 37 °C and 100% humidity for five weeks before retreatment. Filling materials were removed up to the gutta-percha cone’s length. The canals were then randomly assigned to groups: G1 (control, no solution), G2 (5.25% NaOCl), G3 (17% EDTA), G4 (10% citric acid), and G5 (10% formic acid). The apical patency was attempted with a 10 K file within a period of 10 min, by a blinded operator. Additionally, sealer samples were immersed in the solutions, followed by scanning electron microscopy analysis. The Kruskal–Wallis test was used for statistical analysis. Patency was achieved in all canals except one in the control and one in the NaOCl groups. No significant differences were found in the time required to achieve patency. Acid solutions had a greater impact on the sealer’s structural integrity, and a decalcifying effect of EDTA and citric acid was registered. Apical patency in straight canals obturated with AH Plus Bioceramic sealer was consistently achieved regardless of the solution used. Full article

Recently, the single-cone hydraulic canal filling technique using bioceramic sealers was found to hinder retreatment due to the mechanical properties of the bioceramic sealers. This study assessed the effectiveness of four nickel–titanium rotary files in removing gutta-percha and bioceramic sealer from molar root canals in vitro. Eighty-eight root canals from extracted molars were instrumented with Vortex Blue rotary files and filled with gutta-percha and bioceramic sealer using a single-cone technique. After 30 days, the filled canals were randomly divided into four groups according to the file used for re-instrumentation: ProTaper Gold (PTG), Endo ReStart (ERS), XP-3D Shaper (XPD), and HyFlex Remover (HFR). This study assessed whether root canal filling material removal and patency were achieved within a 10-min time frame, recording the time required in seconds. The rate of regaining patency and the time required to achieve patency were compared among groups using a generalized linear model. Scanning electron microscopy was used to evaluate the mechanical changes to the files after use. The patency rate of XPD and HFR was significantly higher than PTG. ERS and XPD demonstrated shorter patency times than HFR and significantly shorter patency times than PTG. SEM images revealed a varied range of reverse windings across file groups. PTG and ERS exhibited microcracks and fractured tips, while XPD and HFR did not display these mechanical alterations. The four file systems in this study displayed varying levels of effectiveness in the retreatment of root canals filled with bioceramic sealers. Full article

Background/Objectives: Since biomineralization by calcium silicate-based sealers (CSBSs) was reported, retrieving canal filling materials may be challenging during endodontic retreatment due to their adhesion to dentin. This study aimed to evaluate the possibility of removing residual mineral deposits from two kinds of CSBSs compared to the AH Plus Jet (AHJ). Methods: Root canals of mandibular premolars were prepared, obturated with the sealer-based obturation method using a WOG medium gutta-percha cone and one of the following sealers: AHJ, AH Plus Bioceramic (AHB), and Ceraseal (CER) (n = 12/group). After 3 weeks, endodontic retreatment was conducted with the WOG files, followed by instrumentation with XP-endo Finisher (XPF). Micro-computed tomography scanning was obtained after canal filling, after retreatment with WOG, and after the use of XPF. The percentage of the removed filling volume was calculated. One-way ANOVA with Tukey’s test and a non-parametric test with Bonferroni’s correction were performed. Root canal dentin after retreatment was examined using a scanning electron microscope (SEM). Results: After supplementary instrumentation with XPF, the mean residual filling volumes for the AHJ, AHB, and CER groups were 1.35 mm³, 0.55 mm³, and 0.82 mm³, respectively. The AHJ group showed greater residual volume compared to the AHB group (p < 0.05). The AHB and CER groups demonstrated higher mean percentages of removed filling volume at 94.8%, and 92.5%, respectively, compared to 87.1% for the AHJ group (p < 0.05). More mineral deposits were observed in the CER group with SEM. Conclusions: AHB and CER are retrievable during endodontic retreatment, with CER preferable due to greater mineral deposits in dentinal tubules. Full article

Background and Objectives: The access cavity design and instrumentation system could affect the remaining root canal obturation materials in root canal retreatment. This study aimed to evaluate the efficiency of two different multi-file systems in removing obturation materials with two different access cavities utilizing micro-CT scanning. Materials and Methods: Conservative access cavity (CAC) preparation was performed for 80 mandibular premolars. Then, root canal preparation was employed followed by obturation. The retreatment process began by dividing the samples into two separate groups: conservative (CAC) and traditional (TAC) access cavities. Subsequently, these groups were assigned to eight distinct subgroups (n = 10): Group 1; TAC and ProTaper retreatment system (PTR) with ProTaper Next (PTN); Group 2, TAC and PTR + ProTaper Ultimate (PTUL); Group 3, TAC and PTN; Group 4, TAC and PTUL; Group 5, CAC and PTR + PTN; Group 6, CAC and PTR + PTUL; Group 7, CAC and PTN; and Group 8, CAC and PTUL. The samples underwent micro-CT scans before and after the retreatment process, and the volume and percentages of remaining root canal filling material were calculated. Statistical analysis of the data was performed, and significance was determined at the 5% level. Results: The influence of the access cavity design (p = 0.500), the ProTaper system (p = 0.138), and the interaction of these variables (p = 0.513) was insignificant. However, group 3 (TAC and PTN) showed the highest percentage of remaining obturation materials at 29.53%, contrasting with group 6 (CAC and PTR + PTUL). Conclusions: Neither retreatment procedure succeeded in completely removing filling materials. Nevertheless, the impact of access cavity design, different multi-file systems, and their interaction on the remaining root canal obturation materials was deemed insignificant. Full article

Objectives: Apical extrusion of debris can affect the success of endodontic treatments, and the specific performance of certain retreatment systems has not been studied yet. Therefore, the aim of this in vitro study was to quantitatively assess the amount of apically extruded debris produced during retreatment procedures using three rotary NiTi retreatment systems in mature non-resorbed straight roots. Methods: Thirty extracted permanent human teeth with single straight roots were selected. The root canals were prepared with the ProTaper Next system up to size 30 and obturated with gutta-percha and AH Plus sealer using the continuous wave of condensation technique. The samples were stored for 30 days and randomized by computer sequence into three retreatment groups (n = 10): (1) ProTaper Universal Retreatment; (2) HyFlex Remover; and (3) VDW.Rotate Retreatment. Apically extruded debris was collected in Eppendorf tubes and weighed with a microbalance (10⁻⁵ g) before and after retreatment procedure. As the data were not normally distributed, the Kruskal–Wallis test was applied for comparing data among groups, with an alpha level set at α = 0.05. Dunn’s test was considered for post-hoc analyses, if appropriate. Results: Hyflex Remover was associated with the highest amount of extruded debris (0.85 ± 0.82 mg), followed by VDW.Rotate Retreatment (0.78 ± 0.41 mg) and ProTaper Universal Retreatment (0.62 ± 0.28 mg). However, the differences were not statistically significant (p > 0.05). Conclusions: All the retreatment systems tested were associated with apical extrusion of debris in vitro, with no significant quantitative differences between them, suggesting that clinicians can choose a retreatment system with features appropriate to the specific clinical situation without risk of increasing the amount of apically extruded debris. Full article

Objectives: To evaluate the retreatment efficacy of premixed bioceramic sealer using a reciprocating system, comparing single-cone and carrier-based obturation techniques. Materials and Methods: Twenty-three monoradicular teeth with oval canals were divided into two groups: NeoSealer Flo with single cone (SC) and NeoSealer Flo with Guttafusion (GF). Retreatment was performed using Reciproc Blue (RB) with a crown-down technique. X-ray and CBCT images were taken to measure the remnant areas and volumes. Results: Apical patency was achieved in all the samples. The remnants were mostly distributed in the middle third in the GF group, while an equal distribution in both the middle and apical thirds was observed in the SC group. The GF group had a lower remnant area and volume after RB 50.05, respectively (0.18 ± 0.33 mm² vs. 0.39 ± 0.80 mm² and 0.36 ± 0.59 mm³ vs. 0.51 ± 1.16 mm³). The use of RB 50.05 led to an additional reduction in the remnant areas in the SC (14.89%) and GF (69.49%) groups, while in terms of the volume, the reductions were 20.63% and 36.36%. Conclusions: Reciprocating instruments are effective in removing remnants from root canals filled with both single-cone and carrier-based techniques. The blooming effect in CBCT imaging suggests further in vivo studies for validation. Full article

This study presents a systematic review with meta-analysis to evaluate the success rates of endodontic retreatments in teeth where separated instruments are located within the roots. The search and selection of studies were conducted across two databases, SCOPUS and PubMed, as well as the Cochrane Library registry, yielding a total of 1620 records. Following the selection process, 11 studies were included in the systematic review. Overall, out of 1133 retreated teeth, there were 172 failures in instrument removal and 55 perforations. The meta-analysis results indicate that failures are more frequent when instruments are located in the apical third, with a failure rate of 21%, compared to an 8.8% failure rate in the middle/coronal third. The anatomy of the root canals, particularly the location of the separated instruments, significantly influences the success rates. Full article

The fracture of nickel–titanium (Ni-Ti) instruments during root canal instrumentation leads to compromised outcomes in endodontic treatments. Despite the significant impact of instrument facture during a root canal treatment, there is still no universally accepted method to address this complication. Several previous studies have shown the ability of a Neodymium: Yttrium–Aluminum–Perovskite (Nd: YAP) laser to cut endodontic files. This study aims to determine safe irradiation conditions for a clinical procedure involving the use of a Neodymium: Yttrium–Aluminum–Perovskite (Nd: YAP) laser for removing fractured nickel–titanium files in root canals. A total of 54 extracted permanent human teeth (n = 54) were used. This study involved nine distinct groups, each employing different irradiation conditions. Groups 1 s, 3 s, 5 s, 10 s, and 15 s simply consist of irradiation for 1, 3, 5, 10, and 15 s, respectively. After identifying the longest and safest duration time, four additional groups were proposed (labeled A, B, C, and D). Group A was composed of three series of irradiations of 5 s each separated by a rest time of 30 s (L5s + 30 s RT). Group B consisted of three series of irradiations of 5 s each separated by a rest time of 60 s (L5s + 60 s RT). Group C consisted of two series of irradiations of 5 s each separated by a rest time of 30 s (L5s + 30 s RT), and group D consisted of two series of irradiations of 5 s each separated by a rest time of 5 s (L5s + 5 s RT). In all groups, during the rest time, continuous irrigation with 2.5 mL of sodium hypochlorite (3% NaOCl) was carried out. The variation in temperature during irradiation was registered with a thermocouple during irradiation with different protocols. The mean and standard deviation of the temperature increase was noted. The calculation of the temperature was made as the Δ of the highest recorded temperature at the root surface minus (−) that recorded at baseline (37°). Additionally, scanning electron microscopy (SEM) was used after irradiation in all groups in order to assess the morphological changes in the root dentinal walls. The Nd: YAP laser irradiation parameters were a power of 3W, an energy of 300 mJ per pulse, a fiber diameter of 200 µm, a pulsed mode of irradiation with a frequency of 10 Hz, a pulse duration of 150 µs, and an energy density of 955.41 J/cm². Our results show that the safest protocol for bypassing and/or removing broken instruments involves three series of irradiation of 5 s each with a rest time of 30 s between each series. Furthermore, our results suggest that continuous irradiation for 10 s or more may be harmful for periodontal tissue. Full article

The objective of this in vitro study was to compare the efficacy of three different rotary systems, namely D-RaCe, R-Endo, and Edgefile XR, in the removal of root canal obturation materials during non-surgical retreatment procedures. Lower first premolars with straight oval canals were utilized, and microcomputed tomography (micro-CT) was employed as an evaluation method. The study also aimed to investigate the influence of two different initial obturation methods, the single cone and the continuous wave compaction techniques, on the amount of residual material after retreatment. The findings revealed that none of the retreatment systems could completely eliminate the obturation material, corroborating existing studies. However, Edgefile XR outperformed the other systems in terms of reduced residual material. The continuous wave compaction method for initial obturation resulted in fewer remnants compared to the single cone technique. This contradicts prior research suggesting that the two methods offer comparable sealing abilities. The study underscores the advantages of using micro-CT for evaluation, as it provides a more accurate three-dimensional assessment of the residual materials in the canals. Despite its limitations, such as the focus on straight canals and the in vitro setting, the study provides crucial insights for clinicians. It suggests that the choice of rotary system and initial obturation method can significantly impact the success of root canal retreatment procedures. Full article

Aim and background: Periapical lesions, which occur due to the infection and necrosis of dental pulp, are a significant dental pathology that poses risks to oral and systemic health. These lesions often require interventions such as root canal treatment or periapical surgery. Recent research has focused on the effectiveness of biocompatible materials, including mineral trioxide aggregate, bioceramics, and leukocyte-platelet-rich fibrin (L’PRF), in improving healing outcomes. This report presents the application of leukocyte-platelet-rich fibrin (L’PRF) derived from the patient’s autologous blood to enhance bone healing. Case description: A 61-year-old woman with well-controlled hypertension and good oral hygiene visited the dental clinic due to a painless swelling near her upper left central incisor. After examination, it was determined that she had a periapical granuloma. The patient underwent successful root canal retreatment and apical surgery, during which leukocyte-platelet-rich fibrin was applied. After 30 months, she experienced significant improvement with no symptoms and substantial bone regeneration. Conclusion: Clinical evidence and this case study indicate that leukocyte-platelet-rich fibrin (L’PRF) may enhance healing post periapical surgery. Further research, including more extensive and longer-term randomized trials, must confirm L’PRF’s effectiveness and refine treatment protocols. Clinical significance: L’PRF enhances bone healing post periapical surgery. Clinicians should consider integrating L’PRF in periapical surgeries, ensure diligent follow-up, and inform patients of its long-term advantages. Further randomized trials are needed to refine L’PRF clinical guidelines. Full article

Hydraulic calcium silicate-based (HCS) sealers have recently gained tremendous popularity due to their unique properties. However, their removal during endodontic retreatment is challenging. The solvent, which could chemically deteriorate the material, would be highly desirable for endodontic retreatment procedures. This preliminary study assessed the interplay and dissolving capability of 10% and 20% citric acid, compared to 17% EDTA, on commonly used HCS sealers (AH Plus Bioceramic Sealer, Bio-C Sealer, BioRoot RCS, TotalFill BC Sealer), and evaluated the potential impact of these solutions on root dentin structure. The interaction between tested sealers and irrigating solutions was photographed, and solubility-related mass changes were determined. The surface morphology of treated filling materials and dentin was evaluated using a scanning electron microscope (SEM). One-way analysis of variance (ANOVA) along with Tukey’s test were used to detect the statistically significant differences among groups at the confidence level of 0.95. Intense gas release was observed during the interaction of HCS materials and citric acid, with no evidently visible “bubbling” after the immersion in EDTA. The mass loss of HCS sealers equally confirmed the significantly higher dissolving characteristics of 10% and 20% citric acid solutions compared to EDTA. The surface structural changes, associated with pore and crack formation, were mainly seen for HCS sealers exposed to citric acid. Meanwhile, no severe erosion was detected for dentin after root canal preparation with 10% and 20% citric acid solutions. These findings demonstrate that citric acid has the potential to dissolve HCS sealers with minimal or no negative impact on root dentin, suggesting citric acid as a solvent for HCS sealers in endodontic retreatment procedures. Full article

This review explores the field of retreatment strategies for cases filled with calcium silicate-based root canal sealers. Since the introduction of calcium silicate-based materials in dentistry, calcium silicate-based root canal sealers have become popular among dentists because of their biocompatibility, bioactivity, and sealing ability. Therefore, effective retreatment strategies are indispensable. This article aims to identify the challenges associated with the removal of calcium silicate-based sealers themselves and removal of gutta-percha with the sealers during retreatment, evaluate current techniques and materials, and provide future directions for research in this field. Regarding the strategies of removal of root canal sealers, calcium silicate-based sealers are still relatively new materials for clinicians compared with traditional sealers such as epoxy- or eugenol-based sealers. First, no clinically established solvents have been reported. Second, calcium silicate-based sealers are currently utilized by clinicians in either the cold sealer-based technique or the warm vertical condensation technique. Third, the setting process of calcium silicate-based sealers generates byproducts, primarily calcium hydroxide and secondarily hydroxyapatite, that could interact with dentine. Lastly, there is a lack of clinical studies evaluating the efficacy of retreatment protocols for teeth filled with calcium silicate-based sealers. Therefore, it is important to investigate the chemo-mechanical properties of calcium silicate-based sealers themselves and their reactions to solvents and/or mechanical instruments and identify the interfacial properties of calcium silicate-based sealers with respect to dentine and gutta-percha. In addition, researchers in the clinical field need to actively gather and report data on retreatments of teeth filled with calcium silicate-based sealers. Full article

Background: All endodontic treatment techniques are associated with the extrusion of debris into periradicular tissues through the apex. The extrusion of apical debris can lead to delayed healing or even therapy failure. It is possible to reduce the extrusion into periapical tissues through various approaches. The objective of this systematic review is to evaluate whether, in cases of non-surgical endodontic retreatment, reciprocating instruments cause greater extrusion of debris compared to instruments with continuous rotation. Methods: A search was conducted on PubMed, Ovid MEDLINE, and the Web of Science. The inclusion criterion was in vitro studies comparing apical extrusion in endodontically treated elements using continuously rotating and reciprocating files. Results: The search on scientific databases yielded 164 results, out of which only 16 were eligible for evaluation after screening. Conclusions: The authors of the research included in this review do not agree on the results obtained. Based on the articles analyzed in this systematic review, it remains unclear whether continuous rotation or reciprocating movement of the endodontic instrument can lead to significant differences in apical debris extrusion; it is not possible to provide a clear clinical recommendation regarding the choice of instrument movement for endodontic procedures. Full article

This study aimed to assess the amount of erosion during activated endodontic irrigation with either HEDP or EDTA via high-resolution micro-computed tomography. Two root canals of twenty premolars were prepared with ProTaper Next and irrigated with sodium hypochlorite. Palatal canals, which served as control groups, were sealed, while buccal canals were further irrigated with either EDTA (n = 10) or HEDP (n = 10), which served as test groups. Micro-CT was performed to measure erosion depth. For 2D and 3D measurements, non-parametric repeated ANOVA measurements and post hoc tests were performed. 2D analysis showed highly significant differences between the case groups at each position of the root (p ≤ 0.01). The cervical and apical positions showed significant differences in the EDTA group (p = 0.03). The 3D analysis also showed significant differences between both chelating agents (p < 0.01) and the case and control groups (p = 0.01). The mean erosion depths in the cervical, middle, and apical thirds of the EDTA group were 45.75, 41.79, and 32.25 µm, and for the HEDP group were 20.25, 16.40, and 15.96 µm, respectively. HEDP seems to have a significantly less erosive effect. Different irrigation protocols with harsher conditions, as might be the case during endodontic retreatment, could be assessed with micro-CT. Full article