A laboratory study comparing the static navigation technique using a bur with a conventional freehand technique using ultrasonic tips for the removal of fibre posts.

AIM: There are currently no high-quality studies comparing the static navigation technique with conventional methods of fibre post removal. The aim of this ex vivo study was to compare the effectiveness of fibre post removal between a static navigation technique and a conventional freehand technique using ultrasonics by experienced and inexperienced operators. METHODOLOGY: Forty-eight extracted single-rooted human premolars were root-filled. A fibre post was cemented in all 48 teeth, which were then divided randomly into the following groups: static navigation group using burs; static navigation-ultrasonic group; and non-guided group using ultrasonic tips. The following parameters were evaluated for both experienced operators and inexperienced operators: reaching the gutta-percha root filling successfully, the time required to remove the entire post, the occurrence of lateral root perforations, and the amount of root dentine removed. The Kolmogorov-Smirnov test was used to examine the normality of the data; the anova test was used to compare the significant differences among groups; and Tukey tests were used for all two-by-two comparisons. The significance level was set at 0.05. RESULTS: In the static navigation group, the gutta-percha was reached significantly more frequently than in the non-guided group (p < .05). The static navigation approach required significantly less time than the non-guided approach to reach the gutta-percha (p < .05). The total removal of posts was significantly different between groups (p < .05), but there was no significant difference between experienced and inexperienced operators in the static navigation group (p > .05). More perforations were associated with the non-guided group than with the other two groups. The total mean loss of dentine in the non-guided group in all directions was 0.39 (±0.17) mm, with 0.25 (±0.09) mm for experienced, and 0.42 (±0.16) mm for inexperienced operators. CONCLUSION: When compared to a conventional ultrasonic technique for the removal of fibre posts, the static navigation method using burs resulted in less dentine removal, more rapid access to the gutta-percha root filling, less overall time to remove the posts, and fewer complications. When using static navigation, there was no difference in performance between experienced and inexperienced operators.

Intracanal removal and apical extrusion of filling material after retreatment using rotary or reciprocating instruments: A new approach using human cadavers.

AIM: This study compared intracanal removal of filling as well as the frequency and volume of extruded material after retreatment with either HyFlex or Reciproc instruments in mandibular teeth from cadavers. METHODOLOGY: The root canals of 14 pairs of contralateral single-rooted teeth in mandibles of cadavers were instrumented with Reciproc R40 and filled using lateral compaction. The mandibles were scanned in a micro-computed tomographic (micro-CT) device before and after retreatment procedures. The contralateral teeth were assigned to two groups (n = 14) according to the retreatment protocol using either HyFlex or Reciproc instrument systems. In the HyFlex group, the HyFlex Remover instrument was worked 3 mm short of the working length (WL), followed by HyFlex CM 40.04 and 50.04 at the WL. In the Reciproc group, the R50 instrument was worked up at the coronal two thirds, followed by two more cycles until the WL was reached. Pre- and post-operative micro-CT images were analysed for extrusion and intracanal removal of filling material. RESULTS: After retreatment, extrusion of filling material occurred in 11 (78%) and 14 (100%) teeth from HyFlex and Reciproc groups respectively (p > .05). A similar volume of extruded material was observed after retreatment with both systems (p > .05). A significant decrease in the intracanal filling volume was verified after retreatment with both tested systems (p < .05). However, residual filling material was found in all root canals, regardless of the system. The amount of filling material removed (HyFlex = 80.8%; Reciproc = 65.9%) and the operation time was similar between systems (p > .05). CONCLUSIONS: A high frequency of filling material extrusion was observed after retreatment with the two systems in a cadaver model, with no significant difference between them. Both protocols obtained similar efficacy in filling material removal procedures, although none completely cleaned the canals.

Post-operative pain in non-surgical root canal treatment after sealer-based obturation versus warm vertical compaction: A randomized clinical trial.

AIM: Post-operative pain may occur after non-surgical root canal treatment (NSRCT). The root filling technique and choice of sealer may be contributing factors. This randomized controlled clinical trial compared post-operative pain and analgesics intake after NSRCT using a sealer-based obturation technique (SBO) with single-cone gutta-percha and calcium silicate sealer (CSS) versus a warm-vertical compaction (WVC) technique with gutta-percha and a resin-based sealer (RBS). METHODOLOGY: This study was designed as a parallel-two arm, double-blind, randomized superiority clinical trial registered at www. CLINICALTRIALS: gov (NCT04753138). Patients referred for NSRCT fulfilling the inclusion criteria participated in this study. Pre-operative periapical radiographs and CBCT scans were taken and numerical rating scale (NRS) pain scores were recorded. Upon completion of canal instrumentation, participants were randomly allocated to either Group SBO: SBO with CSS or Group WVC: Warm-vertical compaction with RBS. Post-operative pain and analgesics intake were recorded at 1, 3 and 7 days after endodontic treatment completion. Non-parametric Mann-Whitney U and Friedman tests and a generalized estimating equation were used to assess differences in pain scores between the groups, within each treatment group at different time points and for correlations, respectively. RESULTS: The study included 195 participants (212 teeth). One participant declined to submit the NRS form. Therefore, 194 participants (211 teeth) were included in the final analysis (99.5% response rate). No statistically significant differences in post-operative pain or analgesic intake existed between the two groups at any time point (p > .05). Age, pre-operative pain, apical diagnosis and post-operative analgesic intake were significantly related to post-operative pain (p < .05). CONCLUSIONS: Sealer-based obturation technique with CSS was associated with similar post-operative pain levels and analgesics intake as WVC with RBS. Regarding post-operative pain, SBO with CSSs may be a suitable clinical alternative.

The efficacy of premixed bioceramic sealers versus standard sealers on root canal treatment outcome, extrusion rate and post-obturation pain: A systematic review and meta-analysis.

BACKGROUND: Limited evidence is available regarding the superior clinical properties of bioceramic sealers comparted with traditional standard sealers. OBJECTIVES: This review aimed to answer the following research questions: 'In healthy patients requiring a root canal treatment (P), what is the efficacy of premixed bioceramic sealers (I) compared with traditional root canal epoxy resin-based sealers (C) in terms of survival, success rates (PICO1) sealer extrusion and resorption (PICO2) post-obturation pain (PICO3) (O)?' METHODS: Authors independently searched three electronic databases: PubMed (including MEDLINE), Web of Science, Embase and Scopus up to 31 October 2023. This was accompanied by both grey literature and manual search. Detailed selection criteria were applied, namely mature permanent teeth requiring root canal treatment, premixed bioceramic sealer with gutta-percha as an intervention group, a standard filling technique as control group and full-text available in English. A random-effect meta-analysis was used to synthesize the body of evidence regarding the use of bioceramic sealers in root canal treatment and their impact on post-obturation pain. Effect sizes were represented as relative risks on a logarithmic scale for binary outcomes and as mean differences for continuous outcomes. RESULTS: A total of 941 articles were identified. Fifteen Comparative clinical studies were finally included. Eleven were randomized clinical trials, and four were prospective clinical trials with control group. The follow-up of these studies was not greater than 2 years. No publication bias was observed in any study. No significant differences were observed between the two groups in terms of survival and success rates. A small non-significant lower risk of extrusion was observed for bioceramics. A small, non-significantly lower post-operative-pain within 24-h was observed when bioceramics were used. DISCUSSION: The majority of current evidence shows inconsistencies in reporting and is of short-term duration. Robust prospective long-term trials are needed in this area to better support future recommendations. CONCLUSION: This systematic review is the first to analyse several clinical outcomes using premixed sealers. Included studies differed in terms of clinical protocol and operator expertise, but reported a similar outcome when comparing bioceramic versus standard sealers. Tooth survival, treatment outcome, post-operative pain and periapical extrusion were similar and presented no significant differences between the two sealer types. REGISTRATION: PROSPERO database (CRD42023449151).

Assessment of dental students' knowledge and performance of master gutta-percha cone selection and fitting during root canal treatment: a pilot study.

BACKGROUND: Misconceptions should be detected early in dental students' training to improve their clinical performance. Accordingly, this study aimed to assess undergraduate dental students' knowledge and performance of master gutta-percha (GP) cone selection and fitting during clinical endodontic courses at the College of Dentistry, King Saud University. METHODS: Ninety-nine undergraduate dental students completed an online survey about their knowledge of master GP cone selection. Forty-five of these students were observed by faculty members in clinical endodontic courses while they fitted master GP cones during root canal treatments. The observers recorded the details of each student's cone-fitting techniques. The data were analysed using t-tests, one-way analysis of variance, and chi-square tests (p < 0.05). Inter- and intra-observer reliability were tested using Fliess' Kappa. RESULTS SURVEY: All participants had good knowledge of over-extended cone management, while 80.8% knew how to properly manage a short cone. The proper flaring assessment method was selected by 86.9% of the female and 34.2% of the male students, and this difference was statistically significant (p = 0.0001). OBSERVATION: The students labelled the working length on the master GP cone with an indentation in 64.4% of the cases and by bending the cone 35.6% of the time. Of all students, 84.4% encountered an apical stop, and this rate correlated significantly with the length of the cone on the master apical cone radiograph (p = 0.001). Improper shaping of the canal was the most common cause of ill-fitting cones (83.3%), while 16.7% of the students chose the wrong cone size. The final obturation length was adequate in 80% of the cases; 57.8% of the students were helped by instructors. CONCLUSIONS: Most students had the basic knowledge required to solve problems related to the selection of master GP cones. However, in the clinical setting, more than half of the students required the assistance of an instructor to adjust their cone's fit. The presence of an apical stop had the most significant effect on the length of the fitted master GP cone on radiography. The most common cause of ill-fitting master cones was improper shaping of the canal.

Clinical Approach to Dental Root Canal Filler-Induced Maxillary Sinus Fungal Mass Using Transnasal Endoscopy.

Accidentally extruded root canal filler within the sinuses may induce maxillary sinusitis with fungal mass. The authors describe 2 cases of gutta-percha-induced fungal masses in the left maxillary sinus of 2 women. The lesions were evaluated preoperatively using both computed tomography and magnetic resonance imaging, providing comprehensive insights into the condition. In one patient, the lesion was located such that it could be resected through the middle meatal antrostomy alone. However, the second patient presented with an anteroinferiorly situated lesion that necessitated not only a transnasal approach but also an endoscopic modified medial maxillectomy. Both patients recovered uneventfully after surgery. This case series is the first published report of 2 cases of gutta-percha-induced maxillary sinus fungal masses, with their imaging findings, successfully treated through different routes through transnasal endoscopic surgery. These reports highlight the need for a collaborative approach between dental practitioners and otolaryngologists. In addition to the patient's wishes, surgical interventions must consider the unique characteristics of each case and the potential for collaboration across different medical specialties.

Effect of gutta-percha solvents on the push-out bond strength to root dentin of a syringe-mixed resin sealer and premixed bioceramic sealer.

PURPOSE: To assess the push out bond strength (POBS) of a syringe-mixed resin sealer and a premixed bioceramic sealer to root dentin exposed to different gutta-percha (GP) solvents and to determine the mode of failure. METHODS: A total of 200 horizontal root slices (1 mm thickness) were prepared up to size 40, 0.04 taper and randomly divided into four main groups based on solvent (Endosolv, orange oil, chloroform) and control (saline), then subdivided into two subgroups based on sealer type (AH Plus Jet and iRoot SP). Samples were exposed to respective solvents for 5 minutes and after the final rinsing, canal spaces were filled with either AH Plus Jet or iRoot SP. POBS test was performed 2 weeks after incubation and mode of failure following POBS test was evaluated. Data were analyzed using two-way ANOVA and Dunnett post hoc analysis (P< 0.05). Failure mode patterns were categorized as adhesive, cohesive and mixed failures. RESULTS: There was no significant difference (P> 0.05) in POBS between all solvent groups against the control in both AH Plus Jet and iRoot SP groups. Regardless of the use of solvents, AH Plus Jet group had significantly higher bond strength (P< 0.001) compared to iRoot SP group. The predominant mode of failure was mixed failure in all groups irrespective of type of sealer and exposure to solvents. CLINICAL SIGNIFICANCE: This study showed that exposure to gutta-percha solvents (chloroform, orange oil and Endosolv) for 5 minutes did not affect the bond strengths of both iRoot SP (bioceramic sealer) and AH Plus (resin sealer) to root dentin.

Effect of heat application on the physicochemical properties of new endodontic sealers: an in vitro and SEM study.

Understanding the properties of endodontic sealers is vital for treatment planning. Calcium silicate-based sealers are important in modern endodontics. This study investigates the effect of heat on the physicochemical properties of new calcium silicate sealers, addressing concerns raised by clinicians seeking to combine their benefits with the gutta-percha obturation technique. Five endodontic sealers (AH Plus Bioceramic®, Total Fill® BC®, One-fil® Bioceramic, K-Biocer, Any-seal®) were evaluated. Each sealer (n = 16/group) was either kept at 37 °C or subjected to heat at 60 or 200 °C for 30 s. ISO 6876-2012 standards were used to measure setting time, flow, film thickness, and dimensional changes over time. SEM and EDS were utilized for surface and chemical analysis. Data analysis employed IBM SPSS Statistics version 26 with a 5% significance level for two-sided tests. The sealers' setting times were shortened by heat, except for Total Fill® BC with extended setting time. All sealers had significantly longer setting times than manufacturer specifications. Film thickness increased with temperature, while flow values decreased. K-Biocer sealer showed the highest flow (16.89 ± 0.57 mm) at 200 °C, while Total Fill® sealer had the lowest (15.32 ± 0.62 mm). Shrinkage was significant at 60 °C and 200 °C, with greater shrinkage at 200 °C. Heat caused surface deformations in all sealers. The 200 °C groups exhibited more voids in AH Plus Bioceramic®, Any-seal®, and One-fil® sealers, and higher void area in Total Fill®, One-fil®, and K-Biocer sealers (p value < 0.001). EDX analysis confirmed heat-induced chemical and elemental changes in all tested sealers. Elevated temperature affects the physicochemical properties and structure of the tested endodontic sealers. The consideration of endodontic sealer compatibility is essential when warm gutta-percha obturation techniques are used.

Effectiveness of different supplementary protocols for remaining filling material removal in endodontic reintervention: an integrative review.

The aim of this study was to perform an integrative review to identify the most effective supplementary protocols used after filling material (FM) removal and root canal reinstrumentation, during endodontic reintervention. The literature search was performed on the electronic databases PubMed and Latin American and Caribbean Health Sciences Literature (LILACS), using a combination of specific scientific descriptors. Selection criteria accepted articles published in English, Spanish and Portuguese languages, up to August 2021, involving in vitro and ex vivo studies. After applying the eligibility criteria, 46 articles were included for qualitative analysis. The tool for qualitative analysis of quasi-experimental studies of the Joanna Briggs Institute was used to determine the risk of bias of the included articles. The selected articles provided important data regarding the following supplementary protocols: sonic and ultrasonic activation of the irrigating solution; the use of ultrasonic inserts, XP-endo system instruments, and photon-induced photoacoustic streaming for mechanical debridement; and new devices as GentleWave system, and the self-adjusting file. Overall, all supplementary protocols demonstrated efficacy in removing the remaining FM. The implementation of various supplementary protocols can effectively remove the remaining FM from the root canal walls, although complete removal is not always achieved. However, it was not possible to determine the most effective protocol. Conversely, their association can enhance remaining FM removal. Remaining FM attached to root canal walls hinders proper chemical-mechanical preparation during endodontic reintervention. Supplementary protocols optimize the remaining FM removal, enhancing cleaning and disinfection of root canal.

An automated method to analyze root filling voids and gaps using confocal microscopy images.

This study evaluated the feasibility of an automated method to delimit the required area to quantitatively analyze root filling voids and gaps from cross-sectional confocal laser scanning microscopy (CLSM) images. Root canals of maxillary canines were prepared with rotary instruments and filled by lateral compaction technique using gutta-percha and AH Plus sealer. The roots were stored (100% humidity, 37 °C) for a period of 24 h and then transversally sectioned to obtain 2-mm-thick slices from the apical and middle thirds. The areas corresponding to filling materials, gaps, and voids were manually delimited or automatically demarked by ImageJ software after converting the images to the RGB color system. Based on manual and automatic delimitations, the percentages of voids and gaps were calculated. Data of voids and gaps between middle and apical thirds were individually compared by paired t-test. Pearson`s correlation test was used to assess the correlation of data between the methods. Irrespective of the method of area delimitation, no difference was observed between the root thirds for both voids and gaps, while the p-values calculated for each method were similar. Almost perfect correlations between the methods were observed for both outcomes. The proposed method to automatically delimit the areas corresponding to filling material, voids, and gaps appears to be a valid method to facilitate the quantitative analysis of defects in root canal fillings using topographic CSLM images.

Finite element evaluation of dentin stress changes following different endodontic surgical approaches.

The aim was to compare the effect of different endodontic surgical treatments on the stress distributions in dentin of a simulated first mandibular molar tooth using the finite element analysis method. Three surgical endodontic procedures (apical resection, root amputation, and hemisection) were simulated in a first mandibular molar. Biodentine or mineral-trioxide-aggregate was used to repair the surgery site in apical resection and root amputation models; the remaining root canal spaces were filled with gutta-percha. Access cavities were restored using resin composite. In hemisection model, root canal was filled with gutta-percha, and coronal restoration was finished with a monolithic zirconia crown. A sound tooth model was created as a control model. An oblique force of 300 N angled at 45° to the occlusal plane was simulated. Maximum von Mises stresses were evaluated in dentin near the surgery regions and the entire tooth. Apical resection/Biodentine and apical resection/mineral-trioxide-aggregate models generated maximum von Mises stresses of 39.001 MPa and 39.106 MPa, respectively. The recorded maximum von Mises stresses in root amputation models were 66.491 MPa for root amputation/Biodentine and 73.063 MPa for root amputation/mineral-trioxide-aggregate models. The highest maximum von Mises stress value among all models was observed in the hemisection model, measuring 138.87 MPa. Hemisection induced the highest von Mises stresses in dentin, followed by root amputation and apical resection. In apical resection, Biodentine and mineral-trioxide-aggregate did not show a significant difference in stress distribution. Biodentine in root amputation may lead to lower stresses compared to mineral-trioxide-aggregate.

Comparison of Easydo Activator, ultrasonic and needle irrigation techniques on sealer penetration and smear layer removal in vitro.

The effects of Easydo Activator (EA), a new sonic irrigation system, on sealer penetration at the root apex were compared to needle irrigation (NI) and passive ultrasonic irrigation (PUI) in this study. Forty-two single-rooted teeth were prepared and randomly divided into three groups (n = 14): group 1: NI; group 2: PUI; and group 3: EA. A solution of 3% sodium hypochlorite (NaOCl) was used for irrigation. Nine teeth in each group were filled with AH Plus sealer mixed with CY5 fluorescent dye and a single gutta-percha cone. The sealer penetration area, maximum penetration depth and percentage of sealer penetration at 5 mm and 1 mm from the apex were analyzed by confocal laser scanning microscopy (CLSM). The remaining 5 teeth in each group were subjected to test smear layer scores by scanning electron microscopy (SEM). The CLSM evaluation showed that increases in the area, depth and percentage of sealer penetration were detected at 1 and 5 mm from the root apex in the PUI group compared with the NI group, and greater increases were observed in the EA group (P < 0.05). The SEM experiment showed that the lowest scores for the smear layer and debris removal were achieved by the EA group when compared with the PUI and NI groups (P < 0.05). In conclusion, EA was superior to PUI and NI regarding sealer penetration at the root apex during endodontic treatment, and it could provide a new technical idea for clinical root canal therapy.

Nanostructured ZnO thin film to enhance gutta-percha's adhesion to endodontic sealers.

BACKGROUND: Gutta-percha (GP) combined with an endodontic sealer is still the core material most widely used for tridimensional obturation. The sealer acts as a bonding agent between the GP and the root dentinal walls. However, one of the main drawbacks of GP core material is the lack of adhesiveness to the sealer. ZnO thin films have many remarkable features due to their considerable bond strength, good optical quality, and excellent piezoelectric, antibacterial, and antifungal properties, offering many potential applications in various fields. This study aimed to explore the influence of GP surface's functionalization with a nanostructured ZnO thin film on its adhesiveness to endodontic sealers. METHODS: Conventional GP samples were divided randomly into three groups: (a) Untreated GP (control); (b) GP treated with argon plasma (PT); (c) Functionalized GP (PT followed by ZnO thin film deposition). GP's surface functionalization encompassed a multi-step process. First, a low-pressure argon PT was applied to modify the GP surface, followed by a ZnO thin film deposition via magnetron sputtering. The surface morphology was assessed using SEM and water contact angle analysis. Further comprehensive testing included tensile bond strength assessment evaluating Endoresin and AH Plus Bioceramic sealers' adhesion to GP. ANOVA procedures were used for data statistical analysis. RESULTS: The ZnO thin film reproduced the underlying surface topography produced by PT. ZnO thin film deposition decreased the water contact angle compared to the control (p < 0.001). Endoresin showed a statistically higher mean bond strength value than AH Plus Bioceramic (p < 0.001). There was a statistically significant difference between the control and the ZnO-functionalized GP (p = 0.006), with the latter presenting the highest mean bond strength value. CONCLUSIONS: The deposition of a nanostructured ZnO thin film on GP surface induced a shift towards hydrophilicity and an increased GP's adhesion to Endoresin and AH Bioceramic sealers.

Micro-computed tomographic evaluation on the quality of single-cone obturation using a modified passive-deflation sealer injection needle: an in vitro study.

OBJECTIVES: This study aimed to design a modified passive-deflation sealer injection needle and investigate its ability to improve obturation quality of single-cone technique through assessing the distribution of voids in root canals using micro-computed tomography (micro-CT). MATERIALS AND METHODS: Forty-eight mandibular incisors were divided into eight groups (n = 6), according to the taper of root canal preparation (0.06 or 0.04), the needle used for sealer injection (modified or commercial iRoot SP injection needle), and the obturation method (iRoot SP sealer-only or single-cone obturation). After obturation, each specimen was scanned by micro-CT. The volumetric percentage and distribution of all voids were first analyzed and compared among groups, then the open and closed voids were separately analyzed and compared among single-cone obturation groups. RESULTS: Compared to commercial needle groups, modified needle groups showed much less voids, especially in the apical root canal part (P < 0.05). Besides, the modified needle groups produced much less open voids than commercial needle groups despite the root canal taper (P < 0.05). CONCLUSIONS: The modified passive deflation sealer injection needle could effectively improve the quality of single-cone obturation through reducing intra-canal voids, especially open voids throughout the root canal, thus might possibly be developed as an effective intra-canal sealer delivering instrument.

Post retention strength of apical and conventional coating obturation methods using bioceramic sealer: a laboratory investigation.

BACKGROUND: Once bioceramic sealer (BCS) enters the dentinal tubules, it cannot be reliably removed. BCS-occupied dentinal tubules reduce fibre post retention strength. Coating gutta-percha with BCS only on the apical portion may improve post retention strength due to increased retention strength between the dentin and resin cement interface. The aim of the study was to test this hypothesis. METHODS: Root canals of 27 extracted human mandibular premolars were instrumented and randomly assigned to three obturation methods: conventional coating (CC), non-coating (NC), and apical coating (AC). The root canals were obturated with gutta-percha to 4 mm from the working length under an operating microscope. After the BCS was completely set, post spaces were prepared, and quartz fibre posts were cemented. The apical 4.5 mm of the roots were removed. Two samples were prepared at the apical, middle, and coronal root levels (one for scanning electron microscope (SEM) study and another for the push out bond strength (PBS) test). After the PBS test, the samples were examined with a stereo microscope to determine the failure mode: dentine-cement (DC), post-cement (PC) and mixed. The PBS data were analysed by One way ANOVA for the specific obturation method effects. Repeated ANOVA was used for the specific effects of the root levels on PBS in different obturation methods. RESULTS: At all three root levels, more continuous hybrid layers and denser resin tags were found in the NC and AC than the CC group. The AC and NC groups' PBS was significantly higher than the CC group at the apical 1/3 (p = 0.002 and p = 0.001) and coronal 1/3 (p = 0.016 and p = 0.041). The PBS in the CC group at the middle 1/3 was significantly higher than the apical 1/3 (p = 0.022). DC failure mode was most commonly found in the CC group, while PC failure mode was found most frequently in the NC and AC groups. CONCLUSIONS: The apical coating obturation method significantly increased PBS over the conventional coating method, potentially reducing fiber post dislodgement. However, this study was only preliminary. Clinical studies are required to confirm the results.

Hard tissue formation in pulpotomized primary teeth in dogs with nanomaterials MCM-48 and MCM-48/hydroxyapatite: an in vivo animal study.

BACKGROUND: This animal study sought to evaluate two novel nanomaterials for pulpotomy of primary teeth and assess the short-term pulpal response and hard tissue formation in dogs. The results were compared with mineral trioxide aggregate (MTA). METHODS: This in vivo animal study on dogs evaluated 48 primary premolar teeth of 4 mongrel female dogs the age of 6-8 weeks, randomly divided into four groups (n = 12). The teeth underwent complete pulpotomy under general anesthesia. The pulp tissue was capped with MCM-48, MCM-48/Hydroxyapatite (HA), MTA (positive control), and gutta-percha (negative control), and the teeth were restored with intermediate restorative material (IRM) paste and amalgam. After 4-6 weeks, the teeth were extracted and histologically analyzed to assess the pulpal response to the pulpotomy agent. RESULTS: The data were analyzed using the Kruskal‒Wallis, Fisher's exact, Spearman's, and Mann‒Whitney tests. The four groups were not significantly different regarding the severity of inflammation (P = 0.53), extent of inflammation (P = 0.72), necrosis (P = 0.361), severity of edema (P = 0.52), extent of edema (P = 0.06), or connective tissue formation (P = 0.064). A significant correlation was noted between the severity and extent of inflammation (r = 0.954, P < 0.001). The four groups were significantly different regarding the frequency of bone formation (P = 0.012), extent of connective tissue formation (P = 0.047), severity of congestion (P = 0.02), and extent of congestion (P = 0.01). No bone formation was noted in the gutta-percha group. The type of newly formed bone was not significantly different among the three experimental groups (P = 0.320). CONCLUSION: MCM-48 and MCM-48/HA are bioactive nanomaterials that may serve as alternatives for pulpotomy of primary teeth due to their ability to induce hard tissue formation. The MCM-48 and MCM-48/HA mesoporous silica nanomaterials have the potential to induce osteogenesis and tertiary (reparative) dentin formation.

Quality of different obturation techniques to fill perforating internal root resorption: a micro-computed tomographic study.

BACKGROUND: This study aimed to assess the quality of various obturation techniques to fill perforation caused by internal root resorption using Micro-computed Tomography. METHODS: Cone-beam computed tomography images of a maxillary central incisor tooth with perforating internal resorptive defect were used to create a 3D printed model of the affected tooth. The replicas were divided into four groups based on the obturation technique used. The techniques included Group 1: a polydimethylsiloxane-based sealer (GuttaFlow-2) with gutta-percha. Group 2: same as Group 1 except for using a pre-mixed Bioceramic-based sealer (NeoSEALER Flo). Group 3: the defect was filled entirely using the NeoSealer Flo Bioceramic-based sealer. Group 4: the samples were obturated using the warm vertical compaction technique with a resin-based sealer (ADSeal). The resin models were then scanned a micro-computed scanner to evaluate the percentage of voids in each group. RESULTS: The results showed that NeoSEALER Flo groups had significantly the highest volume of voids while GuttaFlow-2 and warm vertical compaction groups had the lowest void volume. CONCLUSIONS: GuttaFlow-2 and warm vertical compaction techniques performed best in filling the internal resorptive defect.

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.

[Sealing effect of GuttaFlow2 in curved root canals].

OBJECTIVE: To evaluate the sealing ability of GuttaFlow2 single cone obturation in curved root canals. METHODS: (1) Slight, moderate and severe curved 3D printed root canals were made. After instrumentation, these samples were randomly divided into 2 groups (n = 10) according to different root canal filling techniques: GuttaFlow2 single cone group (GF2) and AH-Plus warm vertical compation group (WVC). All the samples were sectioned at 2 mm to apex (the apical of the root), 4 mm, 6 mm to apex (the middle of the root) and 8 mm to apex (the coronal of the root). The filling void areas were observed by stereomicroscope, and the percentages of void areas in each section were calculated by ImageJ 1.52a. (2) Forty-eight roots of extracted adult molars were selected. After instrumentation, they were randomly divided into 2 groups (n = 8): GF2 group and WVC group. Before root canal filling, the sea-lers were mixed with Rhodamine B dye for visualization under confocal laser scanning microscope. All samples were sectioned at 2 mm to apex (the apical of the root), 5 mm to apex (the middle of the root) and 8 mm to apex(the coronal of the root). Then, the percentages of sealer penetration into dentinal tubules in each section were calculated. RESULTS: At the apical of the root, there were no obvious voids in slight, moderate and severe curved canals in the GF2 group and the WVC group. There was no significant difference between the two groups (P > 0.05). At the middle of the root, there was no significant difference in the percentages of void areas between the two filling methods, but at the coronal of the root, there were more voids in the slight curved root canal in the GF2 group than in the WVC group, and the difference was significant (P = 0.009). The percentages of sealer penetration into dentinal tubules of slight, moderate and severe curved root canals in the GF2 group were 36.10%, 55.80%, 65.08%, respectively. And they were all higher than those in the WVC group (15.78%, 20.70%, 15.61%), respectively, the difference between the two groups was significant (P = 0.001). At the middle of the root, the percentages of sealer penetration into dentinal tubules of slight and moderate curved root canals in GF2 group were also significantly higher than those in the WVC group (P = 0.001). At the coronal of the root, there was no significant difference between the two groups (P > 0.05). CONCLUSION: GuttaFlow2 filling technique has the same sealing effect on the root canal at the apical and middle of the root as the warm vertical technique, but has a better sealing effect on the dentin tubules, especially for severe curved root canal.

Comparative Evaluation of Push-out Bond Strength of Three Different Root Canal Sealers: An In Vitro Study.

AIM: The aim of this present study was to compare the dislodgement resistance of calcium silicate-based sealer, zinc oxide sealer, and a new sealer combining both zinc oxide and calcium silicate-based sealer in vitro. MATERIALS AND METHODS: 60 single-rooted human teeth were instrumented with F3 Protaper Gold. All endodontic canals were filled using gutta percha cones using the cold lateral condensation technique in combination using one of the mentioned sealers (n = 20 per group). The teeth were divided into three groups: group A consisted of Sealite® Ultra, group B consisted of K-Sealer®, and group C consisted of BioRoot® RC. After 2 months of incubation (37°C, 100% humidity) and after cutting out 2 mm from the most apical portion of the root apex, six slices of 1 mm thickness were generated. Mechanical dislodgement resistance was examined using a universal pressure-testing machine and the push-out bond strength (POBS) was calculated. Specimens were examined under 20× magnification to define the bond failure mode. Statistical analysis was executed using ANOVA, post hoc Turkey test for pairwise comparisons and Kruskal-Wallis tests. RESULTS: The POBS of BioRoot® was significantly higher than the POBS of the two other sealers with a mean of 10.54 MPa ± 2.10 and 5.73 MPa ± 2.34, respectively (p < 0.001). Sealite® and K-Sealer® showed similar results in the median and coronal part. K-Sealer® revealed highest POBS compared with Sealite® in the apical part (p < 0.05). CONCLUSION: The POBS of the zinc oxide and calcium silicate-based sealer was significantly lower compared with calcium silicate. Sealite® and K-Sealer® exhibited almost same results. BioRoot showed the highest POBS of all sealers. CLINICAL SIGNIFICANCE: The current study was needed to evaluate the bond strength of three different cements to dentinal walls, by evaluating their respective POBS in vitro. The findings of this study may provide guidance for the clinician in the selection of an adequate endodontic sealer that guarantees an enhanced adhesive seal between the Gutta-percha and the dentinal canal walls. How to cite this article: Makhlouf MP, El Helou JD, Zogheib CE, et al. Comparative Evaluation of Push-out Bond Strength of Three Different Root Canal Sealers: An In Vitro Study. J Contemp Dent Pract 2024;25(1):15-19.