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).

Clinical outcome of non-surgical root canal treatment using different sealers and techniques of obturation in 237 patients: A retrospective study.

OBJECTIVES: The aim of this retrospective study was to compare the clinical results of two root canal sealers and three obturation techniques used for non-surgical root canal treatment. MATERIALS AND METHODS: A total of two hundred eighty-three root canal treated teeth in two hundred thirty-seven patients with minimum a 6-month follow-up was included for this study. The canals were filled with three different modes: 1) cold lateral condensation (CLC) and AH Plus Sealer; 2) continuous wave condensation technique (CWC) and AH Plus Sealer, and 3) sealer-based obturation technique (SBO) and AH Plus Bioceramic Sealer. The treatment outcome was analysed based on clinical signs and symptoms, and periapical radiograph (periapical index, PAI). RESULTS: There were no significant differences in treatment outcome between various sealers and filling techniques applied. The sealer extrusion was found most frequently in the CWC group (60.67%), followed by SBO (59.21%) and CLC (21.19%) with statistically significant differences (p < .05). The initial diagnosis, previous treatment and sealer extrusion (p < .05) were prognostic factors that affected treatment outcome. CONCLUSIONS: Based on the findings of this study, neither the sealer type nor the filling technique affected the treatment success while preoperative diagnosis, previous treatment and sealer extrusion had significant effect on the outcome. CLINICAL RELEVANCE: A bioceramic sealant applied along with the single-cone technique might be considered as an alternative method in root canal obturation.

Ex-vivo evaluation of clinically-set hydraulic sealers used with different canal dryness protocols and obturation techniques: a randomized clinical trial.

OBJECTIVES: This 2-part randomized parallel triple-blind clinical trial adopts a unique model assessing clinically-set hydraulic calcium silicate-based sealers (HCSBS) after different root canal dryness protocols and obturation techniques. METHODS: For the first phase of the study, 24 teeth scheduled for orthodontic extractions were allocated into four groups according to the canal dryness protocol and the obturation technique. G1 (CLC-AHP): cold lateral compaction (CLC) with AH Plus sealer, G2 (CLC-ES-SD): CLC with Endosequence (ES) after standard canal(s) dryness (SD); G3 (SC-ES-SD): matching single-cone (SC) with ES after SD; G4 (SC-ES-PD): as G3 but after partial canal(s) dryness (PD). Teeth were extracted after one month of clinical service and examined for intracanal voids by micro-CT (2D & 3D). For the 2nd phase, another 24 teeth were allocated into four groups according to the root canal dryness protocol and the HCSBS used (ES or CeraSeal (CeS)). Teeth were extracted after one month and sectioned vertically for energy dispersive X-ray (EDX)/scanning electron microscope (SEM) examination. One-way ANOVA with Games-Howell post-hoc test and Chi-square test with multiple z-tests were used for statistical analysis. RESULTS: SC-PD showed the highest percentage of voids (p < 0.05). MicroCT scans as well as EDX/SEM examination showed that PD resulted in significantly larger interfacial gaps (p < 0.001) with more hydration products at the sealer/dentin interface than SD. CONCLUSIONS: Both tested dryness protocols allowed the hydration of HCSBS and the formation of hydration products, thus standard dryness is recommended to reduce the incidence of intracanal voids. CLINICAL RELEVANCE: When using the single-cone obturation technique, intentional root canal moisture negatively affects the performance of HCSBS. PROTOCOL REGISTRATION: http://www. CLINICALTRIALS: gov, ID: NCT05808062.

Effects of radiotherapy dose and application time on the load-to-failure values of teeth filled with different sealers.

BACKGROUND: The materials used in root canal filling and radiotherapy (RT) application can affect the load-to-failure of the teeth. This study aimed to compare the load-to-failure of the teeth filled with AH Plus (AHP) or AH Plus bioceramic (AHPB) before or after 60 Gy- and 70 Gy-dose radiotherapy. MATERIALS AND METHODS: One hundred and ten maxillary incisors were endodontically prepared up to ProTaper Next X4 instruments. The teeth were randomly divided into 5 main groups as: non-irradiated, root canal treatment (RCT) before 60 Gy radiotherapy, RCT before 70 Gy radiotherapy, RCT after 60 Gy radiotherapy, RCT after 70 Gy radiotherapy. These groups were divided into 2 subgroups for filling material: AHP ve AHPB. After filling and radiotherapy procedures, the teeth were fixed on the thermoplastic mask plane. The plane were placed in the middle of a rectangular prism shaped glass phantom, and irradiated via a linear accelerator device. The teeth were then embedded in cylindrical acrylic blocks and the force (N) that caused the fracture was recorded under the Universal testing device. Student t-test was used for statistical comparisons. Statistical significance level was determined as p < 0.05. RESULTS: After 70 Gy dose radiotherapy, the group filled with AHPB showed statistically significantly lower fracture strength than the group filled with AHP (p < 0.05). In the control group, before 60 Gy RT group, after 60 Gy RT group, and before 70 Gy RT group, the sealers had statistically significantly similar load-to-failure. (p > 0.05). CONCLUSION: The group filled with AHPB caused a lower fracture strength than the group filled with AHP following a 70 Gy dose of RT. The sealers in the control group, before 60 Gy RT group, after 60 Gy RT group, and before 70 Gy RT group exhibited comparable load-to-failure values.

Influence of sonic activation of epoxy-resin and calcium silicate sealer on postoperative pain: a patient-blinded, parallel group, randomized clinical trial.

BACKGROUND: This clinical study aims to compare postoperative pain after single-visit root canal treatment of teeth with asymptomatic apical periodontitis using epoxy-resin-based AH Plus and calcium silicate-based Endosequence BC sealers with or without sonic activation. METHODS: This study included 72 individuals with one first or second mandibular premolar tooth with asymptomatic apical periodontitis. They were randomly divided into four groups according to the root canal sealer (AH Plus or Endosequence BC) and activation protocol (sonic activation or non-activation) (n = 18). The participants were ask to rate their postoperative pain intensity on a NRS scale as none, minimal, moderate, or severe after 24 h, 48 h, 72 h, and 7 days following treatment. Patients were also asked to record the number of prescribed analgesic medication tablets (400 mg of ibuprofen) taken. Statistical analysis were performed using the Mann-Whitney U test, the Friedman test, the Spearman's correlation test, the Chi-square test. Significance level was established at 0.05. RESULTS: There was no statistically significant difference in postoperative pain scores or analgesic intake between AH Plus and Endosequence BC sealers regardless of the activation protocol (p > 0.05). There was no statistically significant difference in postoperative pain scores between the sonic activation and non-activation groups (p > 0.05). A weak positive correlation was detected between Endoactivator sonic activation and sealer extrusion (r = 0.36). CONCLUSIONS: AH Plus and EndoSequence BC root canal sealers showed similar results in terms of prevalance and intensity of postoperative pain. Sonic activation and non-activation groups had similar postoperative pain scores. CLINICAL TRIAL REGISTRATION: The study was retrospectively registered with ClinicalTrials.gov (NCT06403293). Date of Registration: 07/05/24.

The effect of sealer type and obturation technique on the fracture resistance of endodontically treated roots.

OBJECTIVE: This study evaluated the effect of sealer type with various obturation techniques on the fracture resistance of root filled teeth. MATERIALS AND METHODS: Eighty mandibular premolars were collected, and root canals of 70 of them were prepared by Mtwo system up to 40/04. Thirty teeth were obturated using TotalFill BC sealer, and 30 using AH Plus sealer, with one of the obturation techniques (N = 10), namely cold lateral compaction (CLC), warm vertical compaction (WVC), and single cone (SC). Ten teeth were left without obturation as a positive control, and the other 10 teeth were not prepared serving as a negative control. Teeth were stored for 3 weeks, and the crowns were separated and the roots were subjected to fracture test using a universal testing machine. RESULTS: Data was analyzed by ANOVA followed by Tukey's test. Fracture resistance of the TotalFill groups was significantly higher than the AH Plus groups in each obturation technique, and SC had the highest fracture resistance regardless of sealer used (P < 0.05). Obturation of the root canal by TotaFill BC sealer increased the calcium/phosphorous ratio in the dentin of the root. CONCLUSIONS: Obturation with TotalFill BC sealer improved the fracture resistance of the roots more than AH Plus sealer, and obturation with SC resulted in higher fracture resistance than CLC and WVC. CLINICAL RELEVANCE: Obturation of the root canal with Bioceramic sealer with single cone obturation technique could reduce the incidence of vertical root fracture.

Influence of long -term thermal cycling and masticatory loading simulation on bond strength of roots filled with epoxy resin and calcium silicate based sealers.

BACKGROUND: The aim of this study was to evaluate the effect of thermal and mechanical cyclic aging using a mastication simulator on push-out bond strength of mandibular premolars obturated with AH Plus and BioRoot RCS root canal sealers. METHODS: With REVO-S files up to SU/0.06 taper, 48 single-rooted premolar teeth were instrumented. The teeth were randomly divided into two main groups (n = 24) based on the two root canal sealers used (AH Plus and BioRoot RCS). All teeth were obturated with h matched-taper single-cone. Each main group was then subdivided into three subgroups (A, B, and C) (n = 8). Group A served as the negative control group (no-thermocycling aging). While groups B and C were subjected to thermal changes in a thermocycler machine (15,000 and 30,000 thermal cycles, respectively), followed by two different dynamic loading periods, 3 × 105 and 6 × 105 in a masticatory simulator with a nominal load of 5 kg at 1.2 Hz which represent roughly 1½ and 3 years of clinical function respectively. 2 mm slice at 3 levels, apical, middle, and coronal, to obtain 3 sections were prepared and subjected to push-out test using a universal testing machine. Statistical analysis was performed using analysis of variance (ANOVA) followed by a Tukey post hoc comparisons test and an independent T-test. A significance level of 5% was used. RESULTS: After thermal-mechanical cyclic aging, the two root canal sealers showed a significantly decreased in push-out bond strength (p < 0.05), however, AH Plus had significantly higher bond strength values than BioRoot RCS after cycling aging. CONCLUSIONS: It could be concluded that thermal-mechanical cyclic aging had a significant impact on the outcome of the dislodgment resistance of AH Plus and BioRoot RCS.

Effect of continuous chelation on the dentinal tubule penetration of a calcium silicate-based root canal sealer: a confocal laser microscopy study.

BACKGROUND: This study aimed to evaluate the effect of various irrigation protocols on the penetration depth of a calcium silicate-based sealer into dentinal tubules using confocal laser scanning microscopy (CLSM). METHODS: Twenty single-rooted mandibular premolars were endodontically prepared and divided into the following two groups according to the irrigation protocol used (n = 10): Group I: NaOCl + EDTA and Group II: continuous chelation (NaOCl/Dual Rinse). Obturation was performed with the warm vertical compaction technique using TotalFill HiFlow bioceramic sealer mixed with a fluorophore dye. Samples were observed using CLSM at 10× to measure the percentage of sealer penetration and its maximum depth into the dentinal tubules. Data were analysed using one-way ANOVA followed by Tukey's post-hoc test. The significance level was set at p < 0.05 within all tests. RESULTS: Comparing the overall results of all sections tested, no statistically significant differences existed between the groups regarding the percentage of sealer penetration (p = 0.612) and maximum depth of penetration (p > 0.05). CONCLUSIONS: With both types of irrigation used, dentinal tubule penetration was higher in the coronal section than in the apical section. Continuous chelation using NaOCl/Dual Rinse HEDP performed better in the coronal segments, while irrigation using NaOCl + EDTA promoted a higher percentage of sealer penetration in the apical segment.

Effect of obturation technique on penetration of calcium silicate-based sealer into dentinal tubules after endodontic retreatment of mandibular premolars.

OBJECTIVE: Confocal laser scanning microscopy (CLSM) was used to investigate the penetration of endodontic sealers into the dentinal tubules after retreatment using two different obturation techniques. MATERIALS AND METHODS: Thirty mandibular premolars were prepared up to instrument F3 (ProTaper Universal, Dentsply) and filled with Endofill using the single cone technique. The canals were retreated using Mtwo instruments. Reobturation was performed with the Bio-C sealer mixed with a fluorophore dye (Fluo-3) using either the lateral condensation technique (group LC) or the single cone technique (group SC) (n = 15). Teeth were sectioned 2, 4, and 6 mm from the apex and analyzed with CLSM to assess the penetration of the sealer into the canal perimeter and the maximum depth of penetration of the sealer into the dentinal tubules. Data were analyzed using ANOVA and the Student-t and Holm-Sidak tests. RESULTS: In the apical segment, the penetrated perimeter was significantly higher in the LC group than in the SC group (p < 0.05); no significant difference was found in the middle and cervical segments (p > 0.05). In terms of penetration depth, no significant differences were found for any of the segments studied (p > 0.05). CONCLUSION: The LC technique promoted a higher percentage of canal circumference penetrated by the sealer than the SC technique in the apical segment after endodontic retreatment. CLINICAL RELEVANCE: CLSM demonstrated that the LC technique promoted a higher percentage of canal perimeter penetrated by the Bio-C sealer than the SC technique in the apical segment of mandibular premolars after retreatment.

Comparison of the effect of post space preparation time on the apical seal of two different sealers.

BACKGROUND: The present study compared the effect of post space preparation time on the apical seal of two different sealers. METHODS: In the in vitro study, 94 central incisors were used. After the samples' root canal preparation, they were randomly assigned to four experimental groups (n = 21). The samples in groups 1 and 2 were obturated with AH Plus sealer, gutta-percha, and in groups 3 and 4 with Endoseal MTA bioceramic sealer and single cone technique. The post spaces in groups 1 and 3 were prepared immediately and in groups 2 and 4 with a delay. The samples were evaluated at 7-, 30-, and 90-day intervals for apical microleakage using the fluid filtration technique. The data were analyzed with SPSS 25, using three-way ANOVA and independent t-test. RESULTS: The apical microleakage in groups 3 and 4, obturated with Endoseal MTA bioceramic sealer and prepared immediately and after a delay, respectively, was not significantly different between the interval times. In group 2, obturated with AH Plus sealer and prepared for post space with a delay, the apical microleakage was significantly less than all the other groups. Group 1, obturated with AH Plus sealer and prepared for post space immediately, exhibited the least microleakage after seven days, but its microleakage increased over time to reach the level of groups 3 and 4. CONCLUSION: According to the results, the apical microleakage in the AH + sealer group and the delayed post-space preparation method, was significantly less than all the other groups over time.

Comparing the incidence of postoperative pain after root canal filling with warm vertical obturation with resin-based sealer and sealer-based obturation with calcium silicate-based sealer: a prospective clinical trial.

OBJECTIVE: This prospective clinical study compares postoperative pain after single-visit, non-surgical root canal treatment of teeth with irreversible pulpitis using two different root canal filling techniques. MATERIAL AND METHODS: All cases were treated by endodontic residents with a standardized protocol (minimum apical size 35) and filled with one of the two techniques: warm vertical compaction technique (WVT) with gutta percha and epoxy resin-based sealer (AH Plus Jet Root Canal Sealer, Dentsply Maillefer, York, PA, USA) or sealer-based filling technique (SBT) with single cone gutta percha and calcium silicate-based sealer (EndoSequence BC Sealer, Brasseler, Savannah, GA, USA). Surveys were given to participating patients to record pain intensity on a numeric rating scale (NRS, 0-10) at 4, 24, and 48 h postoperatively. Statistical significance was set at 0.05 level. RESULTS: One hundred ninety-four surveys were distributed over eighteen months. Ninety-two patients returned the survey (41 WVT and 51 SBT), of which 38% were asymptomatic irreversible pulpitis cases. The NRS values reduced over time for both techniques. No statistical difference was found between the two groups at the three time points assessed (p > 0.05). Postoperative pain was related to age, gender, presence of preoperative pain, and sealer extrusion (p < 0.05), however not related to preoperative periapical symptoms (percussion/palpation), dental arch, root type, and experience of the provider (p > 0.05). CONCLUSIONS: The intensity of postoperative pain for the two obturation techniques was equivalent at evaluated time points. CLINICAL RELEVANCE: The obturation technique does not influence postoperative pain. After endodontic treatment of symptomatic irreversible pulpitis teeth, the pain subsides in 48 h regardless of the technique. TRIAL REGISTRATION: ClinicalTrials.gov ID: NCT04462731.

Influence of cervical preflaring and root canal preparation on the fracture resistance of endodontically treated teeth.

BACKGROUND: Evaluate the fracture resistance of endodontically treated teeth after cervical preflaring and root canal preparation and to assess the volume of the root canal and the amount of remaining root dentin before and after cervical preflaring. METHODS: Forty-four mandibular incisors were selected using micro-CT scanning and distributed into 4 groups (n = 11) according to the instrument used for cervical preflaring: control group - no cervical preflaring; Gates Glidden - burs size #2 and #3; WXN - 25.07 Navigator instrument; and Easy - 25.08 ProDesign S instrument. Coronal opening was performed, and the canals were prepared with Wave One Gold Primary and filled with an epoxy-resin based sealer and gutta-percha cones. Micro-CT scans were performed before and after root canal instrumentation. All images were reconstructed and assessed for the thickness of mesial and distal root dentin at 3 mm and 5 mm from the cement -enamel junction and for the volume of cervical portion of the canal after preparation. Fracture resistance test was performed applying compressive loads at a crosshead speed of 0.5 mm/min, applied on the palatal aspect of specimens at 135° along the long axis of the tooth. The data were analyzed using ANOVA and Tukey's test (P = .05). RESULTS: Cervical preflaring and canal preparation reduced the dentin thickness (P < .05) and increased the canal volume (P < .05) in all groups at 3 mm an 5 mm. Cervical preflaring with Gates Gliden burs reduced the fracture resistance of endodontically treated teeth (P < .05). CONCLUSIONS: All instruments reduced the dentin thickness and increased the canal volume in the cervical at 3 mm and 5 mm. Gates Glidden reduced fracture resistance of mandibular incisors submitted to cervical preflaring, whereas NiTi instruments did not. CLINICAL RELEVANCE: Cervical preflaring assumes particular importance previously to the root canal preparation because it minimizes the occurrence of operative accidents, and permits more accurate determination of working length and the apical diameter.

Post-obturation pain following the use of carrier-based system with AH Plus or iRoot SP sealers: a randomized controlled clinical trial.

OBJECTIVES: The aim of this study was to compare the postoperative pain after root canal treatment using a carrier-based obturation system and two different sealers. MATERIALS AND METHODS: In this prospective randomized clinical trial, 160 patients were selected. Patients with vital and devital teeth were randomized into four groups using a randomized block design with block sizes of 10 patients each. The groups were devital/vital teeth treated with iRoot SP sealer and devital/vital teeth treated with AH Plus sealer. Patients were prescribed ibuprofen, a 200-mg analgesic, if needed, and postoperative pain was recorded by visual analogue scale at 6, 12, 24, and 72 h after obturation. Pain score and frequency of tablet intake were recorded and statistically analyzed. RESULTS: Results showed that there was no significant difference between groups in the incidence of postoperative pain; however, iRoot SP sealer was associated with less analgesic intake compared to AH Plus sealer. CONCLUSION: The use of different sealers did not significantly affect pain levels. CLINICAL RELEVANCE: iRoot SP sealer was associated with less analgesic intake compared to AH Plus sealer.

Dissolution, dislocation and dimensional changes of endodontic sealers after a solubility challenge: a micro-CT approach.

AIM: To evaluate, using a novel micro-CT approach, the solubility and dimensional changes of an MTA-based sealer inside the root canal system after a solubility challenge. The MTA-based material (MTA Fillapex) was compared to a gold standard epoxy-based endodontic sealer (AH Plus). METHODOLOGY: Ten human mandibular premolars with a single canal were divided randomly into two groups (n = 5) according to the sealer used. The canals were instrumented using the Reciproc System (VDW) with a R40 file and filled with R40 gutta-percha cones and one of the sealers. The filled canals were immediately scanned in a micro-CT, and after that, the teeth were immersed in 20 mL phosphate-buffered saline (PBS) at 37 °C for 7 days, when they were removed and rescanned. Final image stacks were registered against the initial stacks and the numerical difference between the initial and final volume of the filling material was obtained. Calculations were performed to identify dimensional changes of the filling material. All image stacks were 3D rendered to disclose areas of dislocation of the filling material inside or outside the root canal. The Shapiro-Wilk's test revealed that data were normally distributed; thus, the Student's t-test was used to detect statistically significant changes, assuming a 5% α-error. RESULTS: No significant changes were seen for the percentage volume of material lost after the solubility challenge for both AH Plus and MTA Fillapex groups (1.44% and 1.16%, respectively). A significant difference was, however, found for the volume of filling material which revealed dimensional changes after the solubility test (6.68% for MTA Fillapex and 1.09% for AH Plus). In fact, observation of 3D models disclosed that MTA Fillapex was associated with material extrusion through the foramen in all but one sample. In AH Plus filled samples, no material extrusion was detected. CONCLUSIONS: Although the solubility of both sealers was similar using this novel micro-CT approach, MTA Fillapex was associated with significant dimensional changes related to material extrusion through the apex after PBS storage compared to AH Plus.

Incidence of post-obturation pain after single-visit versus multiple-visit non-surgical endodontic treatments.

BACKGROUND: Post-obturation pain is frustrating to both patients and dentists. Its incidence may change with the use of contemporary endodontic techniques. This randomised clinical trial aims to compare the incidence of post-obturation pain at one and seven days after single-visit and multiple-visit non-surgical endodontic treatments. METHODS: Patients who required primary endodontic treatment in the two clinical trial centres in Hong Kong (HK) and in Beijing (PK) were recruited. Three HK dentists and three PK dentists performed endodontic treatments on 567 teeth using the same procedures and materials, either in a single visit or over multiple visits, using either core carrier or cold lateral condensation for obturation. RESULTS: The attrition rate was 5.1%, and a total of 538 teeth were evaluated. Among these teeth, 232 (43%) were operated in HK, 275 (51%) were treated in a single visit, and 234 (43%) were treated using core carrier obturation. Logistic regression analysis showed that teeth with apical periodontitis (OR = 0.35, 95% CI = 0.21-0.57, p < 0.01) and less pre-operative pain (OR = 1.10, 95% CI = 1.03-1.18, p < 0.01) had lower incidences of post-obturation pain after one day. The incidences of post-obturation pain after one day for single-visit and multiple-visit treatments were 24.7% (68 of 275) and 33.5% (88 of 263), respectively (p = 0.50). The incidences of post-obturation pain after seven days for single-visit and multiple-visit treatments were 4.0% (11 of 275) and 5.3% (14 of 263), respectively (p = 0.47). CONCLUSIONS: There was no significant difference in the incidences of post-obturation pain after one day and seven days with single-visit or multiple-visit endodontic treatments. TRIAL REGISTRATION: ChiCTR-IOR-15005989.

Evaluation of the bond strengths of 3 endodontic cements via push-out test.

In this study, the push-out method was used to evaluate the bond strengths of 3 types of endodontic cements according to their composite base: methacrylate, epoxy resin, and an experimental copaiba oil resin. The study hypothesis was that the methacrylate-based and experimental cements would have bond strengths equal to or greater than that of the epoxy resin-based cement. Thirty bovine tooth roots, 18 mm long, were divided into 3 groups (n = 10) based on the chosen cement treatment. After treatment, the specimens were sectioned and submitted to a push-out test. Results showed that there was no statistically significant difference (P < 0.05) between the cements used or between the middle and apical thirds of the roots. It could be concluded that the tested cements had satisfactory and similar bond strengths to dentin.

Endodontic management of C-shaped root canal system of mandibular first molar by using a modified technique of self-adjusting file system.

AIM: C-shaped canal system is a seldom-found root canal anatomy which displays a challenge in all stages of endodontic treatment. According to the literature, this type of canal morphology is not a common finding in the mandibular first molar teeth. BACKGROUND: This case report presents endodontic management of a mandibular first molar with a C-shaped canal system. CASE REPORT: Root canal system was cleaned and shaped by nickel-titanium (NiTi) rotary instruments combined with self-adjusting file (SAF). Obturation was performed using warm, vertical condensation combined with the injection of warm gutta-percha. Follow-up examination 12 months later showed that the tooth was asymptomatic. The radiological findings presented no signs of periapical pathology. CLINICAL SIGNIFICANCE: The clinician must be aware of the occurence and complexity of C-shaped canals in mandibular first molar teeth to perform a successful root canal treatment. The supplementary use of SAF after application of rotary instruments in C-shaped root canals might be a promising approach in endodontic treatment of this type of canal morphology.

Effect of apically separated rotary instruments on bacterial leakage of obturated root canals using resilon.

The purpose of this study was to determine the effect of a separated rotary instrument on the time required for bacterial penetration of obturated root canals using Resilon. Eighty-four extracted human maxillary premolars with single canals were used in this study. Group 1 consisted of teeth obturated with gutta-percha and AH-26 sealer (n=15); Group 2 consisted of teeth obturated similarly to Group 1 but without a separated file; Group 3 consisted of teeth obturated with Resilon and Epiphany sealer (n=15); and Group 4 consisted of teeth obturated similarly to Group 3 but without a separated file. Six teeth were used as positive controls, and six teeth were used as negative controls for each experimental group. Negative controls were obturated similarly to experimental teeth. On the other hand, positive controls were obturated with gutta-percha or Resilon without sealer. A suspension of Enterococcus faecalis was placed in the access chamber daily, and penetration was determined when turbidity was noted in the culture broth during a three-month period. No significant difference between experimental groups was observed. However, differences between experimental groups and control groups were statistically significant.

Bacterial leakage in root canals filled with AH Plus and dentine bonding agents.

OBJECTIVE: The aim of this study was to compare the efficacy of different dentine adhesives in delaying the coronal bacterial leakage of Enterococcus faecalis in filled root canals. Materials and methods. Ninety-five lower incisors of patients >65 years of age were instrumented using the ProTaper system and were irrigated with 1 mL of 2.5% sodium hypochlorite (NaOCl) alternated with 1 mL 17% EDTA between each file change. Final irrigation was performed with 5 mL of 17% EDTA and then flushed with 5 mL of distilled water. The teeth were randomly divided into five experimental groups (n = 15/group) and one of the following dentine adhesives was applied: (1) AdheSE; (2) Excite DSC; (3) Clearfil Protect Bond; (4) One Coat 7.0; or (5) Control group without adhesive. After filling the root canals, the samples were mounted on a double chamber device to evaluate the bacterial filtration of E. faecalis during a period of 240 days. The results underwent non-parametric Kaplan-Meier survival analysis and comparisons among groups were done using the Log-Rank test. RESULTS: At 240 days, E. faecalis was detected in samples of all groups in the lower chamber. The highest survival value was obtained by One Coat 7.0, giving statistically significant differences from the other groups, whereas Clearfil Protect Bond, AdheSE and Excite DSC showed similar behaviours, likewise similar to the Control group. CONCLUSIONS: One Coat 7.0 adhesive system provides the longest survival value to delay E. faecalis coronal leakage in filled root canals.

Antibacterial activity of various root canal sealers and root-end filling materials in dentin blocks infected ex vivo with Enterococcus faecalis.

OBJECTIVE: The aim was to investigate the antibacterial activity of the root-end filling materials MTA and IRM, different endodontic sealers and calcium hydroxide [Ca(OH)2] in experimentally infected dentinal tubules. MATERIALS AND METHODS: Ninety-four human root segments were prepared and the root canals were enlarged to ISO size 90. After smear removal, the specimens were infected with Enterococcus faecalis for 3 weeks. The roots were divided into eight groups and filled either with MTA, IRM, Ca(OH)2, gutta-percha and EndoRez (ER)/GuttaFlow (GF)/AH Plus (AH+) or with Resilon and Epiphany (EpRe). One group of specimens was left unfilled for control. Half of the specimens were treated for 1 day and the other half for 7 days in humid conditions at 37°C. Dentin samples from each canal were collected by enlarging the canals to ISO size 150; thus a dentinal depth of 300 µm was sampled. The number of cultivable bacteria was determined for each specimen. Statistical significance was set to 5%. RESULTS: After 1-day or 7-days of treatment, compared to control, all materials (except ER and GF at day 7) significantly reduced the number of bacteria. At day 1 and day 7, no significant difference was found between ER and GF and between Ca(OH)2, AH+, EpRe, IRM and MTA. However, a significant difference was found between these two groups of materials (except between GF and EpRe at day 7). Significantly more bacteria were cultured in the ER, GF, EpRe and IRM groups at day 7 compared to day 1. CONCLUSIONS: All materials exerted varying degrees of antibacterial activity which generally tended to decrease with time. The most stable antibacterial effect throughout the 7-day period was for Ca(OH)2, AH+ and MTA.