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Prefabricated dowels do not always provide intraradicular sealing in the root canal dentin, and the lack of sealing predisposes the dowel to adhesive failure and debonding. It is unclear if fiber-reinforced composite resin dowels provide better sealing.The purpose of this in vitro study was to evaluate the intraradicular sealing and morphological fit of prefabricated dowels and fiber-reinforced composite resin dowels in root canal dentin. The thickness of the resin cement layer and push-out bond strength were determined to assess their effects on the sealing of the dowels.A total of 50 permanent maxillary central incisors were endodontically treated and divided into 2 subgroups (n=25). In one group, prefabricated dowels were cemented; in the second group, fiber-reinforced composite resin dowels were placed. The thickness of the resin cement layer was assessed in 3 different locations: coronal, middle, and apical of the root canal dentin with fluorescence confocal laser microscopy. The push-out bond strength was then determined, and intraradicular sealing observed by using scanning electron microscopy.Fiber-reinforced composite resin dowels showed a closer intraradicular fit and seal in the root canal dentin, and the morphology of the apical portion of the fiber-reinforced composite resin dowels showed a sealing area with the gutta percha in the apical portion. The mean thickness of the resin cement layer was significantly reduced for the fiber-reinforced composite resin dowels compared with the prefabricated dowels (P.05) in the cervical area (197.0 μm versus 311.0 μm) and in the apical portion of the root canal (57.3 μm versus 131.6 μm). The mean push-out strength was higher for the fiber-reinforced composite resin dowels (22.98 N/mmThe morphological fit of fiber-reinforced composite resin dowels provides better intraradicular sealing in the cervical and apical portions, reducing the resin cement thickness. The increased push-out strength can therefore be assumed to result from increased frictional retention compared with prefabricated dowels.

The effectiveness of root canal therapy in endodontic practice is largely determined by providing a compact fluid-tight closure at the apex of the root canal, which inhibits irritant entry and buildup, which leads to a biological breakdown of the attachment mechanism and failure. During obturation, along with gutta-percha, root canal sealers are employed to fill voids and seal root canals. Root canal sealers come in a variety of shapes and sizes, each with its own set.Evaluation of sealing ability in vitro study by using scanning electron microscopy (SEM) and biocompatibility in vivo animals study of BioRoot RCS and meta Biomed bio_ceramic sealer (CeraSeal RCS) and compared the findings with that of Zinc oxide eugenol (ZOE) sealer as control.This study utilized two bio_ceramic sealers (BioRoot RCS and meta Biomed bio_ceramic sealer (CeraSeal RCS) and compared the findings with that of ZOE sealer as control. Biocompatibility was determined by examining histopathological biopsy specimens collected from rabbits. Each rabbit had four dentin tubes implanted into the subcutaneous tissues, one for BioRoot RCS, one for CeraSeal RCS, and one for ZOE RCS, with the fourth tube being empty haematoxylin and eosin were used to stain histological sections, and a light microscope was used to evaluate them. Extracted human single canal premolars were used to evaluate the sealing ability. The root canals were divided into three sections (coronal, middle, and apical). SEM was used to assess the adhesion quality at the sealer-dentin interface.BioRoot and CeraSeal sealers have excellent sealing adaptation and biocompatibility, as well as rapid tissue recovery, while ZOE sealers have a slower recovery of inflammatory reaction results when compared to bio_root and ceraSeal sealers, as well as a less sealing adaptation than the two other bio_ceramic sealers.In general, the two bioceramic sealers tested were biocompatible and capable of sealing or adhesion. While ZOE had less adherence ability and less biocompatibility.

This study evaluated the centralization of the region of interest (ROI) in acquisition of the CBCT images, when the freely positionable scout-view (SV) function is applied. Additionally, the dosimetry of the acquired images was assessed in the SV function alone as well as in complete tomographic image in two different fields of view (FOV) (50x50 and 78x150mm). A three-location device was created to accommodate the dosimeters and the specimens, in the right, middle and left location during image acquisition. For dose assessment, thermoluminescent dosimeters were irradiated within the FOV and analyzed in a portable reader. For ROI evaluation, three specimens of gutta-percha stick were placed on the same device and the CT scans were acquired (CBCT OP 300 Maxio device, 90kV, 13mA, 85 µm voxel size, FOV of 50X50mm), with and without the SV, in three positions (3-9, 1-7 and 5-11 o’clock), simulating different regions of the mouth. Two image evaluations were performed, an objective and subjective. There was a slight percentage increase (1.36% to 1.40%) of the radiation dose with the use of SV. The distances were significantly greater in the images acquired without SV (p < 0.05). Every image obtained with SV was classified as being at the FOV’s center. In conclusion, the results demonstrated that SVs function is effective to centralize the ROI in the FOV, increasing the scan precision and avoiding repetitions due to positioning errors. Resumo Este estudo avaliou a centralização da região de interesse (ROI) na aquisição das imagens de TCFC, quando a função scout-view (SV) posicionável livremente é aplicada. Adicionalmente, a dosimetria das imagens adquiridas foi avaliada isoladamente na presença da função SV, bem como após aquisição de imagem tomográfica completa em dois diferentes campos de visão (FOV) (50x50 e 78x150mm). Um dispositivo de três localizações foi criado para acomodar os dosímetros e os espécimes, na localização direita, central e esquerda, durante a aquisição das imagens. Para avaliação da dose, dosímetros termoluminescentes foram irradiados dentro dos campos de visão e analisados em leitor portátil. Para avaliação da ROI, três espécimes de guta percha foram colocados no mesmo aparelho e as tomografias foram adquiridas (CBCT OP 300 Maxio, 90kV, 13mA, 85 μm tamanho de voxel, FOV de 50X50mm), com e sem a SV, em três posições (3-9, 1-7 e 5-11 horas), simulando diferentes regiões da boca. Foram realizadas duas avaliações de imagem, uma objetiva e outra subjetiva. Houve um leve aumento percentual (1,36% para 1,40%) da dose de radiação com o uso de SV. As distâncias foram significativamente maiores nas imagens adquiridas sem SV (p < 0,05). Todas as imagens obtidas com SV foram classificadas como sendo do centro do FOV. Em conclusão, os resultados do presente estudo demonstraram que a função scout view é eficaz para centralizar a ROI no FOV, aumentando a precisão do escaneamento e evitando repetições devido a erros de posicionamento.

To assess the interfacial adaptation (gap-containing areas) of two root canal sealers (EndoSequence BC Sealer and AH Plus) to a conventional gutta-percha (GP) cone (GP-sealer interface) in oval-shaped canals filled using the single cone technique.Sixteen teeth with oval-shaped canals were selected, scanned in a micro-computed tomographic device, and pair-matched according to the volume, aspect ratio and configuration of root canals. Root canals were then sequentially prepared with WaveOne Gold Primary and Large instruments, followed by filling with WaveOne Large GP points associated with either the premixed calcium-silicate EndoSequence BC Sealer or the epoxy resin-based AH Plus sealer (n = 8 per group) using the single cone technique. After 7 days stored in phosphate-buffered saline solution at 37°C, the specimens were rescanned and the reconstructed images segmented in order to differentiate the filling materials (sealer and GP cone) to the dentine. A total of 453 cross-sectional slices were assessed and categorized according to the presence or absence of gaps at the GP-sealer interface. Mann-Whitney U-test verified the differences between groups and were considered significant at alpha = 5%.Gaps were non-homogenously distributed in two-dimensional axial cross-section images and none of the specimens showed completely gap-free areas along the entire GP-sealer interface. Root canals filled with EndoSequence BC Sealer and AH Plus displayed 171 (37.75%) and 136 (30.02%) slices with gaps in the GP-sealer interface and these frequencies were statistically significant (p = .000).Although none of the specimens had a gap-free area along the entire GP-sealer interface, oval canals filled with AH Plus showed less gaps than the ones filled with EndoSequence BC Sealer.

This study aimed to investigate the effect of the heat-based obturation technique on the push-out bond strength of the classical bioceramic and new HiFlow sealer. Fifty single-rooted human mandibular premolars were obturated using one of the following techniques: (1) BC-SC; (2) BC-W; (3) HiFlow-SC; (4) HiFlow-W; and (5) AH Plus-W. Following obturation, specimens were sectioned into 1-mm-thick root slices 4 and 8 mm from the working length and were subjected to a push-out bond test using a universal testing machine and examined for their modes of failure under an inverted phase-contrast microscope. At both distances tested, there was no difference in the push-out bond strength among the four bioceramic groups (P 0.05). The AH Plus-W group had lower bond strength than every other group at both distances from the working length. The most common failure mode was mixed failure.

OBJECTIVE The present study evaluated the efficacy of three different supplementary cleaning protocols on the removal of bioceramic-based root canal filling materials from oval-shaped canals. MATERIALS AND METHODS A total of 36 human mandibular premolars were instrumented and obturated with gutta-percha and iRoot SP using the single-cone technique. Retreatment was performed with ProTaper Universal retreatment files. The samples were randomly divided into the following supplementary cleaning protocols: conventional syringe irrigation (CSI), passive ultrasonic irrigation (PUI), and XP-endo Finisher R (XPR). The samples underwent micro-CT scanning to quantify the amount of residual filling materials after retreatment and after performing the cleaning protocols. The volume of filling material removal was analyzed by one-way analysis of variance and post hoc Bonferroni and Games-Howell tests (P

The aim of this study was to evaluate the influence of surface topography of gutta-percha (GP) cones and plasticized disks of GP on the initial adhesion of Enterococcus faecalis (E. faecalis). The GP cones (Tanari and Dentsply brands) were cut 3 mm from the apical portion and fixed on a glass slide. To make the disks, the cones were thermoplasticized in standardized molds. The specimens were divided into groups according to the shape of the GP and the presence or absence of the bacteria. For contamination, the strain of E. faecalis (ATCC 29212) was used. The surface topography was analyzed using an atomic force microscope (AFM). The surface, roughness, and waviness parameters were evaluated by the Kruskal–Wallis and Dunn test. The comparison between disks and cones showed significant differences, where the cones were rougher, with a higher value attributed to the Dentsply cone (DC group). The same was observed for the waviness. After contamination, there was greater bacterial accumulation in cones, especially in their valleys, but both the surface and the topography became more homogeneous and smoother, with no differences between disks and cones of both brands. The topographic surface of the GP, at the micro and nanoscale, influences the initial adhesion of E. faecalis, with a greater tendency for contamination in regions associated with the presence of roughness and waviness. In this context, plasticization of GP is indicated, as it reduces surface irregularities compared to cones, contributing to less retention of bacteria.

BackgroundThe aim of the present review was to identify the effect of the post-space preparation (PSP) timing (immediate or delayed) on endodontically treated teeth.MethodsAll studies in any language that compared the effect of immediate versus delayed PSP on the outcomes of an endodontically treated tooth were searched in PubMed, Scopus, Web of Science, Cochrane, ProQuest, WorldCat, and Google Scholar databases by two independent researchers until February 12, 2022. Studies assessing merely the immediate or delayed PSP were excluded. A descriptive analysis was performed to evaluate the study design and the characteristics of the included studies.ResultsThe initial search yielded 2612 records, of which 68 were included. Except for one randomized controlled trial, all were in vitro. The evaluated variables were apical/coronal microleakage (n = 48/n = 1), post-bond strength (n = 8), bacterial infiltration (n = 7), presence of voids (n = 3), apical extrusion and residual of filling material (n = 1), and post-operative pain (n = 1). The number of publications had steady growth per year and fast growth per decade. "Post-space preparation" was the most popular keywords.ConclusionsThe present review highlights the need for further investigations due to the various design of studies, controversial results, and an inadequate number of randomized controlled trials.Trial registrationRetrospectively registered. Open Science (https://doi.org/10.17605/OSF.IO/2YTM6).

OBJECTIVE: This study aimed to evaluate the efficacy of three methods in root canal retreatment to remove the filling material in the root canals. METHODS: Ninety tooth roots filled by gutta percha or plasticized material (n=45, each) were randomly divided into three groups (n=15). WaveOne (WaveOne group), 1(#)P drill+WaveOne (1(#)P+WaveOne group), and ultrasound P5 working end ET25+ProTaper Universal (P5+ProTaper Universal group) were used to remove the root canal filling material and prepare for root canal. The operating time of each canal was recorded and the percentage of residual filling material area was measured on the root canal wall of the mesial and distal dissected root section. The degree of deviation of the root canal after operation was measured for the root samples filled by gutta percha. RESULTS: The type of root filling material and the method of root canal retreatment had no significant effect on the percentage of residual area of the filling material (P>0.05). However, the remaining filling material area of apical 1/3 of the root canal was significantly higher than that of cervical 1/3 of the root canal (P

Background: The failure of root canal treatment is non-hermetic obturation. It could be prevented with the use of sealer material. The sealer with an excellent bond to the dentin is epoxy resin and glass ionomer cement sealer. Eucalyptus oil is a natural substance that could dissolve gutta-percha because it has an antimicrobial effect and is biocompatible. Objective: To determine the effect of softening with Cajuput Oil on root canal filling with epoxy resin and glass ionomer cement sealers. Methods: The design of this study was pure laboratory experimental, 24 samples of single root canal block, each block was prepared with step back technique and obturation with lateral condensation. The samples were treated differently by the type of sealer used and incubation time. Group of treatment will be dripped with 0.1 ml of cajuput oil for 5 minutes. Compressive loading was performed apico-coronally by Universal testing machine using cylindrical stainless-steel plunger speed of 2 mm/min until softening occurred. The data were processed using a one-way ANOVA and Post-Hoc Tukey test with a significance level of 95% (p

Despite enjoying high favourable outcome rates, root canal treatment is not always successful. Root canal retreatment is a widely practised option for managing a non-healing root treated tooth. A basic distinction between retreatment and initial treatment is the requirement to remove the existing root filling material occupying the root canal space. Only then, can the technical deficiencies and possible causes of failure be addressed. Hence, the successful removal of the root filling material is critical to achieving the objectives of retreatment. Many different materials and techniques have been used for root canal filling, which have been documented in a plethora of studies; these are mainly laboratory studies investigating the removal of root filling materials. To help guide future research, which may then better inform clinical practice in relation to retreatment procedures, the focus of this narrative review is on the research methods and experimental models employed to study the removal of root filling materials. The current available literature demonstrates great variation in the research methodologies used to study the removal of root filling material, including direct visualization by splitting tooth samples or clearing, three-dimensional radiographic imaging including using microcomputed tomography or cone-beam computed tomography, and a combination of these techniques. Depending on the research method employed, variation also exists in quantification of root filling material removal; these include measurements of surface area, volume or weight, and criteria-based (semi-quantitative) assessment. Experimental models, using human teeth or resin models, differ with respect to standardization techniques and replication of the clinical scenario including initial sample preparation, canal filling, allocation and technical aspects of retreatment procedures. Future models should replicate, as closely as possible, the clinical scenario. Currently, microcomputed tomography provides a highly detailed, non-invasive and non-destructive method of objectively assessing and quantifying root filling removal.

Background: Teeth with apical periodontitis that either persisted or developed after initial root canal treatment is most often indicated for retreatment procedure. The present study was conducted to compare the WaveOne and NeoEndo retreatment file system for the removal of gutta-percha from the root canal. Materials and Methods: Fifty extracted mandibular first premolars with single straight roots were divided into two groups, Group I-WaveOne and Group II-NeoEndo. All samples were scanned with cone-beam computed tomography after the root filling and retreatment procedures. The decrease in the volume of filling material after each retreatment protocol was measured. Results: The mean volume of gutta-percha in Group I before retreatment was 5.6 and in Group II was 5.3, after retreatment in Group I was 2.7, and in Group II was 4.2. The mean percentage reduction in Group I was 45.2% and in Group II was 23.8%. The difference was significant (P < 0.05). Conclusion: Both systems failed to completely remove gutta-percha. WaveOne was significantly more effective than the NeoEndo retreatment system.

This study evaluated tubule penetration of GuttaFlow Bioseal with cold single cone or carrier-based technique, under confocal laser scanning microscopy (CLSM). Twenty straight single-rooted teeth were instrumented with Hyflex CM and divided in two groups (n = 10) according to the obturation method: single cold gutta-percha cones; experimental carrier-based obturators. GuttaFlow Bioseal, labelled with Rhodamine B dye, was used as sealer in both groups. Teeth transversally sectioned were observed under CLSM. Percentage of sealer penetration and integrity of sealer layer perimeter were measured. Surface and microstructural characteristics of obturators and gutta-percha cones were compared by FEG-SEM and EDX analysis. No significant differences were found between groups for each examined parameter. Significant differences (P < 0.05) were reported mainly within groups. Integrity was similar among and within groups. FEG-SEM/EDX analysis of obturators revealed the presence of Ba and Zn. Carrier-based obturation technique associated with GuttaFlow Bioseal does not seem to affect sealer penetration into dentinal tubules.

Intracanal instrument separation thwarts the ongoing treatment process adding to woes of the dentist as well as the patient because it trammels the cleaning, shaping and filling of root canals. This captiously affect the outcome of endodontic treatment by building more impediments, thus compromising the prognosis. Therefore clinicians must be aware of the possibility of instrument fracture in endodontic practice to stave off this mishap. This article quotes narrative review accentuating the techniques for retrieval of intracanal separated instruments along with factors influencing its removal. (Different techniques for removal of Gutta Percha from root canal system has been discussed in detail in part 1 by the same author).

This study evaluated the performance of the metal artifact reduction (MAR) tool in cone-beam computed tomographic scans using different fields of view (FOVs) in the detection of a root isthmus in mandibular molars with intraradicular posts.Twenty-eight teeth were scanned by micro-computed tomographic imaging (gold standard images). Thereafter, specimens were allocated into the following groups: gutta-percha (teeth without posts, n = 10), a prefabricated metal post (n = 9), and a fiberglass post (n = 9). Cone-beam computed tomographic scans were taken using 8 acquisition protocols, varying the size of the FOV (10 × 5.5 cm and 5 × 5.5 cm) and the MAR tool (disabled, low, normal, and high modes). A root isthmus was evaluated considering a 5-point scale. Data were analyzed considering a 5% significance level.Intra- and interexaminer agreement varied from moderate to substantial. The frequency of correct diagnosis varied significantly in all groups regardless of the image acquisition protocol selected (P .05). In the gutta-percha group, there was no difference in the accuracy, sensitivity, and specificity values between the tested protocols. In the metal and fiberglass post groups, the accuracy values were higher with the "disabled" and "low" modes of the MAR tool regardless of the FOV size. This was also observed for the sensitivity values in the metal post group (P .05).The size of the FOV did not affect the performance of the MAR tool in the diagnosis of a root isthmus in molars with intraradicular posts. Our findings suggest that the use of the tool in the "normal" and "high" modes is contraindicated for this purpose.

For successful endodontics, major emphasis is placed on judicious instrumentation, microbial control and complete obturation of the root canal system. During retreatment of previously endodontically treated teeth, one may encounter variety of different materials, which must be removed before these objectives can be achieved. The intent of this article is to present various methods for Gutta Percha removal from the root canal system to aid in re-treatment attempts. Gutta Percha is the most commonly used obturating material, so, therefore this article deals with various techniques available for its removal in retreatment cases.

This study evaluated the effect of different protocols for Ca(OH)2 removal on the bond strength (BS) of epoxy resin-based sealer in long oval root canals. Forty-eight mandibular incisors with long oval root canals were selected by CBCT. Biomechanical preparation was performed, the samples were filled with Ca(OH)2 paste and distributed in four groups (n = 12): G-without Ca(OH)2 paste (C); G2-syringe/needle (SN); G3-SN + XP-Endo® Finisher (XPF); G4-SN + passive ultrasonic irrigation (PUI). After 7 days, Ca(OH)2 was removed and teeth were filled using AHPlus and guttapercha. In four samples from each group, the sealer was manipulated with 0.1% rhodamine to assess sealer penetration by fluorescent laser confocal microscopy (FLCM). Samples were sectioned in slices for BS, scanning electron microscopy, and FLCM analysis. The BS data were analyzed by ANOVA and Tukey tests (α = 0.05). The lowest BS values were found for the SN group (12.89 ± 4.36) compared to C (35.55 ± 10.05), while PUI group presented intermediate values (28.57 ± 9.35) and the XPF group (31.34 ± 9.8) showed values that were sometimes similar to C group and sometimes similar to PUI group (p > .05). The analysis of the adhesive interface showed evident gaps, with the presence of residues between the dentin and the filling material for the SN group, and for C, XPF and PUI groups juxtaposed adhesive interface. FLCM images showed sealer penetration in the dentinal tubules along the entire perimeter for C, XPF, and PUI groups. Ca(OH)2 removal with XPF and PUI from long oval root canals resulted in higher bond strength values compared to SN, besides better sealer penetration on dentinal tubules and juxtaposed adhesive interface.

Dens invaginatus (DI), which often occurs in the maxillary lateral incisor, is an important issue in endodontics because the treatment complexity increases depending on the degree of invagination and the vitality or nonvitality of the pulp. An 11-year-old female patient with a sinus tract in the gingiva of the maxillary lateral incisors showed peri-invagination periodontitis and double DI on radiography. Cone-beam computed tomographic imaging was used to examine the structure in the root canal in detail, and Oehlers type IIIA and IIIB DI was found. It was also shown that the patient’s bone defect was caused by type IIIA. Because a healthy reaction was observed in the pulp test, the final diagnosis was peri-invagination periodontitis associated with type IIIA of the double DI with vital pulp. We expected the lesion to heal by treating only the type IIIA invaginated pseudo–root canal while preserving the healthy pulp. The invaginated root canal was cleaned under a microscope using ultrasonic instruments and nickel-titanium files to minimize irritation to the pulp. Because the lesion shrinkage was confirmed by cone-beam computed tomographic imaging taken 3 months after the start of treatment, vertical compaction of the warm gutta-percha technique was performed. At the 6-month postoperative recall, the pulp was normal, and the lesions were further improved. Treatment of the main root canal of double DI is complicated. However, proper diagnosis and careful cleaning of the invaginated root canal are essential for healing while preserving the pulp.

The present study was conducted to evaluate the presence of aerobic bacteria, anaerobic bacteria, E. faecalis, F. nucleatum, Propionibacteria sp., Actinomyces sp., and their reduction at various stages of endodontic retreatment with the use of conventional protocol (5.25 % Sodium Hypochlorite (NaOCl) as the irrigant along with Calcium Hydroxide (Ca (OH)2) as intracanal medicament and advocated protocol (SmearOFF as the irrigant along with 2% Chlorhexidine (CHX) gel as intracanal medicament).Twenty eight patients fulfilling the eligibility criteria were selected for root canal retreatment and randomly allocated into two groups. Group 1: Final irrigant as SmearOFF+Chlorhexidine 2% gelas intracanal medicament (n=14). Group 2: Final irrigant as 5.25% NaOCl+Ca(OH)2 as intracanal medicament (n=14). With aseptic environment, access opening was performed followed by Gutta Percha (GP) removal and sample S1 was collected for bacterial analysis. The biomechanical preparation was done by using Reciproc system with additional finishing with XP-Endo Finisher R. Sample S2 was then collected for bacterial analysis after the final irrigation protocol in the respective groups. Intracanal medicaments were placed for one week and sample S3 was collected. All the samples were subjected to qualitative analysis using PCR and quantification was done by Colony Forming Unit (CFU) analysis.Aerobic [28/28], Anaerobic [28/28], Propionibacterium sp. [20/28] and F. nucleatum [24/28] were the most frequently isolated in S1 sample followed by Actinomyces sp. [16/28] and E. faecalis sp. [19/28]. Chemico-mechanical preparation followed by irrigation (S2 sample) resulted in significant reduction of all types of bacteria in both groups. Group-1 (SmearOFF as the final irrigant) had significantly superior efficacy against aerobic bacteria, E. faecalis and F. nucleatum (P0.05) as compared to Group-2 (NaOCl). After medicament placement, significant differences between the groups were noted only for the E. Faecalis group. For the S3 samples, the mean bacterial reduction was significant in Aerobic and F. nucleatum in S3 samples for Group 1 and Group 2.Chemico-mechanical preparation followed by irrigation resulted in significant reduction in bacterial load irrespective of the final irrigant. SmearOFF was significantly better than NaOCl in minimizing bacterial load of E. faecalis and F. nucleatum. 2% Chlorhexidine gel has superior antimicrobial efficacy against E. faecalis and may be recommended in secondary endodontic treatment.

This study aims to compare the fracture resistance of simulated immature teeth after using different thicknesses of Mineral Trioxide Aggregate (MTA) and Biodentine apical plug.Forty human maxillary anterior teeth were selected. Teeth were randomly divided into eight groups of five teeth in each group. Positive control group = 5 teeth; prepared without access cavity preparation. Access cavities of the remaining 35 teeth were prepared, and instrumented with Peeso reamers. Negative control = 5 teeth; filled with calcium hydroxide. Thirty teeth divided into Groups 1 and 2 of MTA (MTA-Angelus, Londrina, Brazil) and Biodentine (Septodant, Saint Maur des Fosses, France) and each group divided into three subgroups: subgroup A - 3 mm apical plug; subgroup B - 6 mm apical plug; and subgroup C: full canal length. The rest of the canals in subgroups A and B were filled with gutta-percha and AH Plus sealer. After the required storage period, all the samples were subjected to fracture testing under universal testing machine and fracture strength was recorded. Data were analyzed using 1-way analysis of variance with the Tukey post hoc test for multiple comparisons.The negative control group showed the lowest fracture resistance compared with the other groups (P0.0001). The 6-mm apical plug subgroup of biodentine showed the highest fracture resistance.Within the limitations of this study, MTA and Biodentine can be used as an apical plug instead of root canal filling material to increase the fracture resistance of immature teeth.

Background: In this review, we evaluated the clinical efficacy of interventions used for the treatment of endo-perio lesions (EPL). Methods: A systematic scoping review of clinical trials was developed. Results: Seven clinical trials were studied. In at least one study group of six of the seven evaluated trials, endodontic and periodontal treatments were performed simultaneously. All trials showed improvement in probing depth in the studied groups; nevertheless, the experimental groups of five studies demonstrated a statistically significant reduction in this parameter. An increase in clinical attachment level was also reported (p < 0.05). Most trials reported an increase in the filling of the bone defect following therapy (p < 0.05). Mechanical periodontal therapy implemented simultaneously with endodontic therapy demonstrated efficacy in the treatment of concurrent EPL without communication. Endodontic treatment and immediate periodontal surgery did not affect the result of the management of combined EPL with apical communication. The use of diode laser, the management of platelet-rich fibrin (PRF) and titanium-prepared PRF, and the implementation of bone grafts plus endodontic treatment with mineral-trioxide or gutta-percha seems to be an adequate strategy in patients with EPL. Conclusions: The treatment of EPL using simultaneous endodontic and periodontal therapies seems to be an acceptable treatment alternative.

To compare the effect of different root canal preparation methods on the incidence of interappointment emergencies (IAE) and root canal filling.A total of 96 teeth requiring root canal therapy due to pulpitis or periapical periodontitis from August 2018 to August 2021 were selected. They were randomly divided into 2 groups: MT group was treated with Mtwo root canal preparation method modified by Mtwo machine nickel-titanium file, while synchronous group was treated with modified Mtwo preparation method and synchronous root canal length measurement. After root canal preparation, the trial point film was taken, calcium hydroxide was used to seal the root canal, and routine thermoplasticizied gutta-percha root canal filling was performed during the follow-up visit. SPSS 22.0 software package was used to analyze the incidence of IAE and filling effect after root canal therapy.There was no significant difference in the incidence of IAE between the two groups immediately after operation, three days and 1 week after operation(P＞0.05); the incidence of IAE in synchronous group was significantly lower than that in MT group at 1 and 2 days after operation(P＜0.05). The qualified rate of root canal filling in synchronous group was significantly higher than that in MT group (P＜0.05).Synchronous method can reduce mechanical stimulation of apical area during root canal preparation, strictly control the working length of root canal and maintain apical barrier, thus reducing the incidence of IAE and effectively improving the qualification rate of root canal filling.

This study compared different methods for cleaning the sealer-contaminated access cavity of upper incisors. After standard endodontic access, the canals of 50 extracted maxillary incisors were chemomechanically prepared and obturated with gutta-percha and epoxy resin sealer. Teeth were randomly assigned to one of five different pulp chamber cleaning protocols (n = 10): air/water spray, ethanol-saturated cotton pellet (CP), ethanol-saturated microbrush reaching the root filling (MB), MB + air polishing (PROPHYflex; KaVo), or MB + etching with 37% phosphoric acid. Each tooth was split and the sealer-covered area of the pulp chamber was determined on images taken before and after cleaning using image analysis software. The sealer-covered area was compared across groups using one-way ANOVA. Greatest mean sealer-covered area reduction was observed for MB + etching (98.0%), MB + air polishing (95.2%), and MB alone (92.8%), yielding a significantly higher sealer-covered area reduction than after air/water spray (8.3%) and ethanol-saturated cotton pellet (53.4%). The upper incisor access cavity is best cleaned with an ethanol-saturated microbrush reaching up to the root filling, followed by air/water spraying and etching. The use of cotton pellets should be discouraged.

To evaluate the percentage volume of voids and gaps in oval-shaped canals obturated using two different methods with a tricalcium silicate–based sealer after short- or long-term storage. The long-term effect of storage on the efficiency of removing filling material was also investigated. Forty premolar teeth with oval-shaped canals were instrumented to Reciproc R25 and obturated using single cone obturation (SCO) or warm vertical compaction (WVC) techniques with gutta-percha and HiFlow sealer. The specimens were stored at 100% humidity and 37°C for 2 weeks or 6 months and scanned using micro-computed tomography. Initial retreatment was performed up to a Reciproc R40, and the operating time was recorded. The residual material in the canal received a supplementary procedure using XP-endo Finisher R (XPFR) files. After each retreatment procedure, the specimens were rescanned. The percentage volume of voids and gaps in the SCO group was higher than that of the WVC group at both 2 weeks and 6 months (P < 0.05). The percentage volume of the filling material removed after initial retreatment and XPFR cleaning was significantly higher in the 6-month group than in the 2-week groups (P < 0.05). The proportion of the residual material decreased significantly when XPFR files were used, compared to the initial retreatment group (P < 0.05) in both storage times. The efficiency of retreatment in the oval-shaped canal was closely related to the storage time rather than the filling technique using a tricalcium silicate sealer. The XPFR instrument proved effective in the removal of the remaining materials from the oval-shaped canal. Obturation of the oval-shaped canal with TSBS using the SCO technique in the coronal area needs to be optimized. The retreatment was less efficacious in freshly filled canals than aged filled canals.

The effects of alkaline pH on the size and surface characteristics of gutta-percha were studied. Forty ProTaper Universal-F2 gutta-percha cones (GPC) were stored individually for 8-weeks. GPC were distributed into 2 groups (n = 20) based on the storage solutions' pH (pH7, pH12). The GPC volume was measured after 1,2,3,4 and 8-weeks using water displacement method and compared to the baseline volume. The surfaces of representative GPCs were analysed using Raman spectroscopy and assessed later using Scanning Electron Microscopy with Energy-Dispersive X-Ray Spectroscopy (EDS). Samples t test was used to compare the change in volume of GPC and a repeated measures Analysis of Variance (ANOVA) was used to compare the effects of storage durations. After 8-weeks, GPCs aged in high-pH exhibited significant drop in their volume (16%) compared with GPCs aged in water (2.5%). The surface of GPCs stored in water or high-pH both demonstrated structural and chemical alterations in comparison with non-aged GPCs.

This study is aimed at comparing the efficacy of heat softening and ultrasonic removal of root-end gutta-percha during retrograde preparation for root apical microsurgery. Recently extracted single-rooted premolars ( n = 40 ) were prepared with standardized endodontically treated and root-end resection and then randomly divided into four groups that received root-end cavity preparation using four different instruments: a diamond-coated ultrasonic tip (AS3D; SACTEON, Paris, France), AS3D with the modified plugger of cordless heat carrier (MSE; B&L Biotech, Bala Cynwyd, PA, USA), stainless steel ultrasonic tip (Jetip-2; B&L Biotech, Bala Cynwyd, PA, USA), or Jetip-2 with MSE. The time required for root-end preparation was recorded. The root apex samples were examined by scanning electron microscopy to assess root surface microcracks and marginal integrity. The remnants of gutta-percha on the cavity walls were evaluated using a stereomicroscope. Statistical analysis was performed using Student’s t -test and Wilcoxon rank-sum test ( P < 0.05 ). Usage of MSE with Jetip-2 significantly reduced preparation time from 99.8 ± 6.8 s to 32.4 ± 1.0 s ( P = 0.009 ), the number of microcracks from 42 to 13 ( P = 0.036 ), and the remnants of gutta-percha from 80% to 20% ( P = 0.041 ). Similar results were observed for AS3D with MSE. The heat softening of MSE was effective in cleaning gutta-percha, thus greatly improving the efficiency of the root-end preparation, thereby producing a root-end cavity with fewer microcracks and better marginal integrity.

To compare the expression of the volumetric alteration (VA) artifact between cylindrical and convex triangular fields of view (FOVs) using high-density materials in different positions in two cone-beam computed tomography (CBCT) devices. Cylinders of five high-density materials (amalgam, chromium-cobalt, gutta-percha, titanium, and zirconium) with known physical volume were individually submitted to CBCT acquisition in four positions inside a polymethylmethacrylate phantom using two different FOV shapes (convex triangular and cylindrical) on the Veraviewepocs® R100 (R100) and Veraview® X800 (X800) devices. Two oral radiologists obtained the tomographic volumes by segmenting each cylinder. The difference between the tomographic and physical volumes corresponded to the VA. These values were analyzed by intraclass correlation coefficient and analysis of variance for repeated measures with Tukey post hoc test (α = 5%). The FOV influenced the VA only in the X800 device (p = 0.014): the VA in the triangular FOV was greater than in the cylindrical FOV. The VA in the triangular FOV of the X800 device was greater than the R100 device (p

We aimed to investigate the in vitro physiologic effects of xylene, chloroform, orange oil and eucalyptus oil solvents for dissolving gutta-percha on L929 and HOB cell lines; 2.5 and 10 mu L mL(-1) of these solvents were tested for 24, 48 and 72 h. Gutta-percha solvents inhibited the proliferation rate of fibroblasts in a dose- and time-dependent manner; however, no inhibition was detected in HOB (evaluated using MTT assay). None of the solvents induced apoptosis/necrosis in HOB cells at

This study aimed to evaluate dentinal tubule penetration of the root canal filling material using various techniques such as cold lateral compaction, new generation thermoplastic core carrier and continuous-wave obturation. The root canals of premolar teeth were instrumented, and the teeth were allocated randomly to three groups (n = 15/group). After the obturation with three different techniques, three sections of 2-mm thickness at 2, 5 and 8-mm from the apex were examined under a confocal laser scanning microscope. The data were analysed of variance with a significance level of P

Background: Attempts for preserving endodontically treated teeth after root canal treatment failure have directed the clinicians to surgical intervention; apicectomies with root end resection followed by placement of root-end filling material. Different techniques are used to assess the quality of the apical seal obtained by root end filling materials. Dye penetration is considered the most popular technique. Objective: this in vitro study aimed to evaluate and compare the apical microleakage of three root- end filling materials. Methods: Twenty one upper incisors were utilized, root canals instrumentation was achieved by ProTaper system. Obturation was conducted by lateral condensation technique using Protaper universal gutta percha points. Teeth were apically resected at an angle of 90° to the long axis of the root and root end cavities were prepared and filled. The samples were coated with varnish, then were immersed in 2% methylene blue solution for 24 hours. Roots were then sectioned bucco-lingually in a longitudinal direction. Extent of dye penetration was detected by the use of stereomicroscope. Results: The highest mean value was recorded in MTA group, followed by Guttaflow bioactive and Endoseal groups, where both almost recorded the same mean values. Tukey’s post hoc test revealed no statistically significant difference between the three tested groups. Conclusion: it can be concluded that; all the three groups showed microleakage and none of the three root-end filling materials was able to achieve perfect apical seal. The result also showed that guttaflow bioactive provides a similar reliable seal compared to MTA Fillapex and Endoseal MTA.

Aim: The aim of the present study was to compare the push-out bond strength of CeraSeal Bioceramic sealer used with Gutta percha in single cone (SC), cold lateral compaction (CLC) and warm vertical compaction(WVC) obturation techniques. Materials and Methods: Thirty single-rooted extracted mandibular premolars were selected and mechanically prepared by ProTaper Next rotary files. The canals were allocated into three equal groups (n=10) based upon the obturation technique as follow; Group I: Bioceramic sealer (CeraSeal) with single cone, Group II: Bioceramic sealer (CeraSeal) with cold lateral compaction technique, Group III: Bioceramic sealer (CeraSeal) with warm vertical compaction technique. Roots were sectioned transversally to a thickness of 1 mm at the middle third. The specimens were subjected to push-out test using the Universal Test Machine. The maximum load utilised at the time of dislodgment was recorded. Intergroup comparisons were performed by one-way ANOVA followed by Tukey’s post hoc test. Results: WVC group showed the highest statistically significant mean push-out bond strength value (6.98±1.99) followed by CLC group (1.06±0.15), while the lowest value was presented in SC group (0.66±0.22) (p < 0.001). Conclusions: CeraSeal Bioceramic sealer showed higher push-out bond strength when used in WVC technique compared to single cone and lateral compaction techniques.

This study intended: to assess use cone-beam analysis‏ of gutta percha removal by Reciproc versus ProTaper Universal retreatment systems. Methods: Thirty extracted humanoid lower first molars were collected. The mesiobuccal canal was selected from each tooth. The mesiobuccal canals were mechanically prepared in a crown-down approach using the “TF Adaptive” setting on Elements Motor. TF Adaptive Green ML1 file (Medium Large) and Yellow ML2 size 35 taper 4% till the file gets to the effective length. the obturation was done by lateral condensation technique with gutta pearch size 35 taper 6%, and AH plus in the same visit, and using gutta pearch size 25 taper 2% as auxiliary cones with spreader size 25. samples were unintentionally split into two investigational groups concurring to the re-treatment method used (n = 15). Group I: Reciproc system, and Group II: ProTaper Universal re-treatment. Cone beam (CBCT) was used to evaluate the gutta percha removal in both groups. Results: less remaining filling material following the wastage of the Reciproc system (0.169mm3) followed by the ProTaper Universal retreatment (1.459 mm3). There was less remaining filling material following the use of the Reciproc system (The rate of decrease was 96.82 %) followed by the ProTaper Universal re-treatment kit (The rate of decrease was 76.17 %). Conclusions: Reciproc was more effective than Protaper Universal files in the elimination of gutta‐percha and epoxy resin‐based sealer during the re-treatment.

Made available in DSpace on 2022-04-28T19:47:03Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-12-01 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) The aim of this study was to investigate the filling ability of a new premixed bioceramic sealer in comparison with an epoxy resin-based sealer in curved root canals using different segmentation methods and voxel sizes in micro-CT images. Twelve curved mesial roots of mandibular molars with two separated canals were selected. All root canals were prepared by using HyFlex EDM files size 25/.08 and filled by the single cone technique and Bio-C Sealer or AH Plus (n = 12). The samples were scanned by micro-CT at 5 μm. The images were analyzed at 5, 10, and 20 μm for the volumetric analysis of voids in filling. Visual image segmentation was performed by two examiners, and the automatic segmentation was accomplished for comparison. Radiopacity of the sealers was evaluated by radiographic analysis. Data were submitted to the two-way ANOVA and non-paired t tests at a significance level of 5%. AH Plus had the highest radiopacity (p .05). There was no difference interobserver, which had similar results to those obtained with automatic segmentation for all voxel sizes evaluated (p >.05). Bio-C Sealer had appropriate filling ability. Visual and automatic segmentation can be applied to micro-CT images with voxel sizes from 5 to 20 μm to evaluate the filling of sealers with adequate radiopacity. Automatic segmentation should be used as a faster method. Department of Restorative Dentistry Sao Paulo State University (UNESP) School of Dentistry Sao Carlos Institute of Physics University of Sao Paulo Department of Restorative Dentistry Sao Paulo State University (UNESP) School of Dentistry CAPES: 001 FAPESP: 2016/00321-0 FAPESP: 2017/19049-0 FAPESP: 2018/19665-6

AIM To present a novel root canal filling technique: Ultrasonic Vibration & Thermo-Hydrodynamic Obturation (VibraTHO), and its rationale with a series of cases. SUMMARY The VibraTHO technique was used to fill the root canals of three clinically challenging cases: A C-shaped mandibular molar with complex anatomy, a C-shaped mandibular molar with an infected root canal system and a periapical lesion that required retreatment, and apically bifurcating mesiobuccal canals with a common orifice in a maxillary second molar. The cases were followed up for 15, 7 and 37 months, respectively. After follow-up, normal periapical status was observed without any noticeable radiographic change in the root canal fillings in each case. Periapical radiographs revealed complete healing of the periapical area in cases with pre-operative periapical lesions.

Background: The bond strength of endodontic sealers with dentin is a very important property for maintaining the integrity and seal of the root canal filling. The aim of this study was to evaluate and compare the effect of various irrigants (QMix, 17% EDTA and 2.5% NaOCl) on the push-out bond strength of AH plus and Bioceramic sealers. Materials and methods: Forty eight freshly extracted maxillary first molars human teeth with striaght palatal root were used in the study. The collected samples were randomly divided into three groups of equal sample size (n=16), according to the final irrigation regimen as follows: Group (1): QMix 2 in 1, Group (2): 17% ethylenediaminetetraacetic acid, Group (3): 2.5% sodium hypochloride. All samples were instrumented using Edge file X7 rotary instrument reaching file size 40/.04 as the final master apical file. After that each group was randomly divided into two subgroups (n=8) according to the type of sealer used: AH Plus and Total Fill BC Sealer. Obturation was conducted using single cone technique with gutta percha (GP) to all experimental roots. Two-millimeter thick slices were obtained from the middle section of the root. Bond strength of sealers was measured via a universal testing machine by using stainless steel plunger. Then, the data were statistically evaluated using two-way analysis of variance (ANOVA) and post hoc test (Bonferroni’s test). Results: The push-out bond strength was significantly increased by the “irrigant” factor (P≤0.05) and by “sealer/irrigation solution” interaction (P≤0.05). Final rinse with QMix solution with BC sealer showed the highest mean value of bond strength (5.976 MPa), with a significant difference with other groups (P≤0.05), while NaOCl with AH Plus sealer showed the lowest mean value of bond strength (3.811 MPa). Conclusion: Final irrigation of the root canals with different irrigants improved the endodontic sealer's bond strength, and QMix had a positive influence on the adhesion of BC sealer.

The aim of this study was to present a new technique for plastic carrier removal in retreatment situations. The gutta-percha technique that uses plastic carrier obturators is one of the most commonly used; however, removing this core is tedious and time-consuming. Two clinical cases were performed by an expert in the field of endodontics, to expose this technique, in which a conical ultrasonic tip with an active point and a Hëdstrom hand file allowed the removal of the plastic carrier quickly and effectively. The use of magnification is indispensable for a predictable success with this method SI

Canal filling must be well adapted to the walls of the root canal to prevent bacterial infiltration. Endodontic seals play an essential role in ensuring tightness, without which the canal filling would suffer infiltrations. This study aimed to evaluate the areas occupied by the two components of the canal filling, as well as the sealer/gutta-percha ratio in the root canals of the maxillary central incisors after their filling using the cold lateral condensation technique with gutta-percha. Thirty extracted upper central incisors were rotatably prepared with ProTaper Universal up to F3 and sealed using the cold lateral condensation technique with gutta-percha. After setting the sealer, the roots of the teeth were sectioned perpendicularly to 1 (L1), 3 (L3), 6 (L6), and 8 (L8) mm from the apex. The surface of the sections was analyzed with a Leica EZ4D stereomicroscope and photographed at two magnification orders: 10x and 25x. The areas corresponding to the gutta-percha, sealer, gaps, and root canal were expressed in pixels using the ImageJ software, version 1.50i. The difference in the representation of sealer areas, gutta-percha and voids was statistically significantly different for all four sections analyzed. The best adaptation of the canal obturation was observed in L1 and L3. The gutta-percha area was statistically significantly higher than that of the sealer for the L1, L3, and L6 levels, while the sealer/gutta-percha ratio recorded the lowest value at the L3 level (0, 30) and the highest at its L8 (0.70) level, without registering statistically significant differences regarding the area at the four analyzed levels. The voids were mostly absent or recorded a minimal percentage area (

Statement of problem Whether the amount of the endodontic obturation material remnants in a root canal prepared for a post is related to variations in the anatomic shape of the canal or whether it varies in different parts of the post space is unclear. Purpose The purpose of this in vitro study was to estimate the extent of root canal contamination with remnants of the obturation material after post space preparation in relation to the anatomic shape of the root canals by means of microcomputed tomography. Material and methods Fifty freshly extracted teeth were divided into 5 test groups with respect to the root anatomy of different tooth types. The root canals were shaped and obturated with gutta percha. The space for the glass fiber post was prepared with standardized drills, and all specimens were scanned by microcomputed tomography. The areas of residual obturation material on the root canal walls in the coronal and apical parts of the prepared post space were estimated by using a 3D visualization software program. Parametric and nonparametric dispersive analysis (analysis of variance and Kruskal-Wallis) and Wilcoxon tests were used for statistical data evaluation (α=.05). Results The estimates of the root canal surface areas contaminated with residual obturation material after post space preparation were significantly larger in premolars (P≤.01), as compared with mandibular incisors and with the palatal roots of maxillary first molars. The contamination areas in different parts of the root canal (apical and coronal) reported significant differences within and between the test groups. Conclusions The extent of root canal contamination with remnants of endodontic obturation material after post space preparation was related to the anatomic shape of the roots and varied in the coronal and apical parts of the prepared post space.

Introduction Dynamic navigation systems are used in dental implantology to optimize the accuracy of dental implant placement. Methods A 30-year-old man was seen at the endodontic clinic of the Universidad Autonoma de Yucatan for pain in the left maxillary lateral incisor. A previously treated tooth with symptomatic apical periodontitis was diagnosed. The patient accepted treatment, and after signing an informed consent form, minimally invasive coronal access was performed through a zirconia crown. Then a post removal was performed with an ultrasonic tip to 2 mm before the apical gutta-percha limit, and the removal of material was completed manually with a K-file. Results This case report demonstrates the use of dynamic navigation to remove a post from under a zirconia crown for the retreatment of a failing root canal procedure. The removal of fiber posts from endodontically treated teeth can present a unique challenge for clinicians. Numerous techniques and instrument kits are recommended for the removal of fiber posts, but the risk of excessive root structure damage is a major concern because the ability to differentiate the color difference between peripheral dentin and a bonded fiber post can complicate the accuracy of the removal. Conclusions The dynamic navigation system enabled minimally invasive removal of the fiber post with a high degree of accuracy, thus ensuring that there was no unnecessary removal of root structure. Dynamic navigation using real-time monitoring could reduce the attendant risk of iatrogenic errors in complex treatment cases.

Background Endodontically treated immature teeth which are restored with cast metal posts are of the most susceptible teeth to fracture. An apical plug is usually used as root end filling in order to seal the wide apical foramen. The current study was performed to evaluate the effect of different apical plug materials (MTA and Calcium enriched mixture cement) at varied thicknesses on fracture resistance of teeth restored with cast metal posts. Methods A total of 40 extracted intact single-rooted human mandibular premolars (removed for orthodontic reasons) were used in the study. The coronal part of each tooth was removed and root canal preparation was performed. A size 4 Gates Glidden drill was used to enlarge the canal and was passed through the apical foramen in order to simulate an immature apex. Samples were randomly divided into 5 groups (n = 8) according to apical plug (control group: No plug, group MTA5: 5 mm MTA plug, group CEM5: 5 mm CEM plug, group MTA3: 3 mm MTA plug, group CEM3: 3 mm CEM plug). Post-space preparations were performed and cast metal post-and-cores were fabricated and cemented. Fracture resistance was assessed using a universal testing machine. Fracture thresholds were recorded and data were analyzed using One-way ANOVA and Dunnett’s T3 tests with significance level at P value Results The analysis showed a significant difference of fracture resistance between groups (P value P value = 0.003). There was no significant difference between other groups (P value > 0.05). Conclusions Within the limits of this study, the evidence indicated that placement of a 5 mm MTA apical plug increased the fracture resistance in simulated immature teeth which are restored with cast metal posts, compared to control group (gutta-percha and sealer). While the results were not as promising for a 3 mm MTA apical plug or either 3 or 5 mm CEM apical plug.

Background Tricalcium silicate-based sealers have been usually indicated for the single-cone technique and result in more residual filling materials in root canal retreatment. Passive ultrasonic irrigation and photon-initiated photoacoustic streaming have been reported to improve the removal efficacy of root canal filling materials. However, the abilities of both techniques combined with NiTi re-instrumentation to remove residual tricalcium silicate-based sealer and gutta-percha have not been compared. The aim of this study was to evaluate the efficacy of laser-activated and ultrasonic-activated techniques in vitro for the removal of the tricalcium silicate-based sealer iRoot SP and gutta-percha after standard canal retreatment procedures with the use of nickel-titanium (NiTi) rotary instruments.

BackgroundThe objective of the present micro-computed tomography (micro-CT) study was to assess the presence of voids in band-shaped isthmuses obturated using three different filling techniques.MethodsTwenty-four artificial molar teeth with a band-shaped isthmus were allocated to three groups (n = 8) for obturation, according to the filling technique: single-cone (SC), continuous wave of condensation (CWC) or lateral condensation (LC). Obturation was performed with gutta-percha (GP) cones and iRoot SP (Innovative Bioceramix, Vancouver, Canada). Post-filling micro-CT scanning was performed. The percentage of filling materials and void volumes were calculated in the isthmus areas and data were analyzed using one-way ANOVA and Tukey tests.ResultsThe mean percentage of void volumes and corresponding filling percentages in the isthmus areas after obturation in the SC groups was 22.98 % ± 1.19 %, 77.02 % ± 1.19 %; in the CWC groups 10.46 % ± 2.28 %, 89.54 % ± 2.28 %; and in the LC groups was 13.14 % ± 1.85 %, 86.86 % ± 1.85 %, respectively.ConclusionsIn band-shaped isthmus area, the obturation quality of CWC was superior to SC and LC techniques.

The aim of this case report was to present using negative apical pressure technique for removal of apically extruded gutta-percha during retreatment procedures. A 22 year-old female patient was referred to the clinic with severe pain, swelling, and tenderness to percussion and palpation in the tooth of #26. Periapical radiograph showed previous root canal treatment of tooth #26 with incomplete root canal fillings. During retreatment procedures gutta-percha apically extruded from mesial root canal. The patient was recalled after one day. At the second session, it was observed that the swelling was increased. One of the tips for calcium hydroxide paste application was adjusted to suction of dental unit. Tip was placed into the canal as deep as possible. After a few attempts, apically extruded gutta-percha was removed and the patient was recalled after one day. At one day from the fragment removal, the swelling was decreased. Calcium hydroxide paste was placed into the canals for one week. At the fourth session, the patient was asymptomatic and the treatment was completed at this session. Keywords: gutta-percha, negative apical pressure, retreatment

Aim The aim of this ex vivo randomized study is to evaluate the efficiency of gutta-percha cones that match a nickel-titanium instrumentation system and nonmatching greater taper cones, when used with continuous warm vertical condensation technique. Material and methods Thirty-six straight canals were prepared using ProTaper Next files, and the apical third was obturated using either ProTaperNext cones (group A), ISO uniform greater taper cones (group B), or nonstandardized cones (group C). Cone adaptation time was quantified by the number of required modifications. Micro-computed tomography was used to measure voids and sealer percentage. Results There was no significant difference between the groups regarding void volume (p = 0.666), percentage (p = 0.379), and the number of modifications (p = 0.757). Sealer percentage, however, was significantly lower in group B when compared to group A (p = 0.0194). Conclusion In straight canals, matching gutta-percha cones were not associated with significantly better obturation or saving time to fit the cone. Clinical significance Using gutta-percha cones that do not match a nickel-titanium instrumentation system to obturate the straight canals with continuous warm vertical condensation technique is as efficient as using matching cones in terms of obturation quality and ease of cone fit.

Introduction: In Cone-beam Computed Tomography (CBCT) images, metallic artifacts by root filling materials reduce the quality of images. It seems that bioceramic sealers produce fewer artifacts than gutta-percha. In this situation, the possibility of VRF detection could increase, and therefore, flap and exploratory surgery would not be needed. The purpose of this study was to evaluate the performance of a bioceramic-based root filling material in the detection of Vertical Root Fractures (VRF) in CBCT imaging. Materials and Methods: This study was conducted at the dental school from March to August 2019, and 100 healthy human mandibular premolar teeth were obtained and randomly divided into two equal groups. The teeth were filled with either AH26 and gutta-percha or bioceramic root filling materials. VRF was induced on half of the decoronated teeth in each group using a Global Testing Machine, and the others were considered control. CBCT imaging was performed by the Cranex 3D machine. Comparisons of the 2 groups were made using the Mann-Whitney test. Results: There was a significant difference between the two groups of bioceramic and gutta-percha in the measured indices, including sensitivity (P=0.017), specificity (P=0.018), positive predictive value (P=0.018), negative predictive value (P=0.018), and accuracy (P=0.011). The Area Under Curve (AUC) also showed a significant difference between the two groups (P=0.011). According to Kappa test results, no significant difference was obtained between the findings of the two observers. Conclusion: Different root filling materials showed a different extent of artifact in CBCT images. Bioceramic root filling material induces fewer artifacts in CBCT images, and the diagnostic value of VRF in CBCT images in the root canals filled with it is greater than those filled with AH26 and gutta-percha.

Aim The aim of this in vitro study was to estimate the penetration depth and fracture resistance of three different sealers and to verify the relationship between the penetration depth and fracture resistance. Materials and methods Sixty single-rooted teeth were selected and root canal preparation was done. After the instrumentation, the teeth were divided into three groups of 20 each. The groups were then obturated with gutta-percha (GP)-AH Plus sealer, Resilon-Real Seal, and propoint-bioceramic sealers, respectively. Ten teeth from each group were sectioned at three different regions (i.e., coronal, middle, and apical thirds of the root canal) and were viewed under a confocal microscope to determine the penetration depth of the sealer. The remaining samples were subjected to fracture resistance under a universal testing machine and the statistical analysis was done by using one-way ANOVA and post hoc Bonferroni tests. Results Propoint-bioceramic group showed the highest fracture resistance values followed by GP-AH Plus sealer and Resilon-Real seal groups with no significant difference noticed between them. Depth of penetration was greater for GP-AH Plus sealer, propoint-bioceramic, with no significant difference followed by the Resilon-Real seal group. Conclusion The newer obturating material propoint-bioceramic group showed a greater fracture resistance. No correlation could be established between the depth of sealer penetration and fracture resistance. Clinical significance Fracture resistance of tooth obturated with propoint-bioceramic sealer combination is significantly greater than GP-AH Plus and Resilon-Real seal combination, thereby showing propoint-bioceramic as a promising obturating material.

BACKGROUND The primary goal of endodontic retreatment is to take out the root filling completely to ensure that the canal is completely cleaned. Gutta percha removal using hand instruments is a time-consuming procedure and tedious for the operator. Therefore, various nickel titanium instruments have been introduced for the effective retrieval of gutta percha. This study was done to compare the efficacy of three different rotary systems compared with manual instrumentation for gutta percha removal during retreatment. METHODS Forty-eight single rooted premolars were prepared and obturated using gutta percha and AH Plus sealer using lateral compaction technique. Samples were randomly divided into four groups of 12 specimens each. Group 1 was retreated with Hedstrom Files (H-Files), group 2 was retreated with pro taper universal retreatment files (PTUR), group 3 with R-Endo retreatment files and group 4 with Neoendo retreatment files. Time taken for the retreatment was recorded for each tooth using a stopwatch. The samples were sectioned longitudinally and observed under a stereomicroscope. Digital images were taken and analysed using digital image analysing software. The data was statistically analysed using Kruskal-Wallis and Post-hoc Mann-Whitney test. RESULTS The Neoendo group showed significantly lower amount of residual material compared to PTUR, R-Endo and the H-Files (P = 0.00). The maximum residual material was observed in the H file group. The time taken for gutta percha removal was least for the Neoendo group followed by PTUR, R-Endo and H-Files. CONCLUSIONS None of the instruments were able to remove the filling material completely. Gutta percha removal using Neoendo and protaper universal retreatment files were faster and more efficient compared to REndo and H files. KEY WORDS Endodontic Retreatment, Protaper Universal Retreatment Files, R-Endo, Neoendo, HFiles

Background Sealing materials are used to fill abutment screw access holes (SAH) to prevent microleakage and protect the central screws in oral implant restoration. However, thus far, no consensus has been reached on sealing material selection. In this study, a comparison of the sealing efficacy and removal convenience of different sealing materials for cement-retained implant restoration was conducted. Methods Various sealing materials were classified into five groups, namely, gutta-percha (GP), temporary restorative paste (TRP), vinyl polysiloxane (VPS), polytetrafluoroethylene (PTFE) tape, and onlay resin (OR), and 35 sets of analog-abutments were allocated into five groups of seven specimens. A sealing efficacy test was conducted using a modified dye-penetration method, in which a lower absorbance indicated better sealing efficacy. For the removal-convenience test, the materials were removed from each SAH after solidification, and the retrieval time was recorded. Results On days 1 and 10, PTFE exhibited the highest absorbance value with significant differences compared to the other groups. On day 30, TRP and PTFE showed significantly higher absorbance values than GP, VPS, and OR, but no significant difference was detected between TRP and PTFE (p = 0.424). The absorbance values of TRP and PTFE from days 1, 10, and 30 showed significant intragroup differences, while those of the other groups did not. In terms of the removal convenience on days 1, 10, and 30, VPS achieved the best performance, followed by PTFE, OR, TRP, and GP. Conclusion Within the limitations of this experiment, VPS and OR showed better sealing efficacy against microleakage and a more convenient removal than the other materials; thus, VPS and OR are recommended for clinical use.