The Effect of Final Irrigation Agitation Techniques on Postoperative Pain after Single Visit Root Canal Treatment of Symptomatic Irreversible Pulpitis: A Randomised Clinical Trial.

OBJECTIVE: To evaluate the degree of postoperative pain and rate of analgesic intake in patients with symptomatic irreversible pulpitis in mandibular first molar teeth at 6 h, 12 h, 24 h, 48 h, and 72 h after using different irrigation activation techniques in single-visit endodontic treatment. METHODS: A total of 78 patients with symptomatic irreversible pulpitis with no signs of periapical pathology were randomly divided into 3 groups according to the final irrigation activation technique; Group XP-endo Finisher, Group Ultra X ultrasonic device, and Group side-vented needle. The teeth underwent standardised single-visit root canal treatment procedures using 2.5% sodium hypochlorite for irrigation. Each patient was given a chart to record postoperative pain at 6, 12, 24, 48 and 72 hours intervals. Ibuprofen, 400 mg tablets, was prescribed to be taken when the pain was unbearable. The incidence and number of analgesic tablets taken were recorded. Data were analysed using a Kruskal-Wallis test followed by a pairwise Mann-Whitney U test with Bonferroni correction for intergroup comparisons and Freidman's test followed by Dunn's post hoc test for intragroup comparisons. RESULTS: No statistically significant difference was found between all groups regarding the incidence and intensity of pain at different time intervals (p>0.05). There was no significant difference in analgesic intake between different groups, with most cases in all groups not taking analgesics (p>0.05). CONCLUSION: Adding XP-endo Finisher or passive ultrasonic irrigation to the final irrigation protocol in singlevisit endodontic treatment had no significant effect on postoperative pain or analgesic intake. (EEJ-2021-11-185).

Histopathological and immunohistochemical profiles of pulp tissues in immature dogs' teeth to two recently introduced pulpotomy materials.

OBJECTIVE: The pulpal response to Hoffmann's Pulpine mineral (PMIN) and Pulpine NE (PNE) was compared to mineral trioxide aggregate (MTA) when used as pulpotomy materials in immature permanent teeth in dogs. MATERIALS AND METHODS: Immature premolars were randomly divided according to the observation period into three equal groups (n = 24) (10 days, 30 days, and 90 days) then furtherly subdivided into 3 subgroups according to the material used. Histopathological analysis regarding inflammatory cell infiltration and dentin bridge (DB) formation was done. Immunohistochemical analysis was performed using osteopontin marker. RESULTS: The results showed that after 90 days, both MTA and PMIN subgroups had 100% complete thick DB without inflammation in 87.5% of the samples, while the PNE subgroup failed to form DB in 37.5% of the samples and 50% of samples showed thin initial DB with heavy inflammation in 62.5% of the samples. There was no significant difference between MTA and PMIN, while there was a statistically significant difference between PNE and the two other subgroups in DB formation and inflammatory cell infiltration (P > 0.05). After 90 days, MTA showed the highest mean value of osteopontin positive fraction area followed by PMIN without statistically significant differences, while the least value was recorded in PNE subgroup with statistically significant difference with the remaining subgroups (P < 0.05). CONCLUSION: PMIN is a promising alternative to MTA when used for pulpotomy. CLINICAL RELEVANCE: Vital pulp therapy in immature teeth can be done using PMIN as an alternative to MTA.

The Effect of Trypsin-Chymotrypsin on Postoperative Pain after Single Visit Endodontic Treatment: A Randomized Controlled Trial.

INTRODUCTION: The efficacy of trypsin-chymotrypsin in postoperative pain management following single-visit root canal treatment of teeth with symptomatic irreversible pulpitis was evaluated. Additionally, synergistic effects with nonsteroidal anti-inflammatory drugs and reported side effects were also investigated. METHODS: This prospective, parallel, triple-blinded phase IV randomized controlled trial included 60 patients with mandibular first molars exhibiting symptomatic irreversible pulpitis. The patients were randomly allocated using computer software to one of four treatment groups (n = 15 each), and either ibuprofen (600 mg), ambezim-G (trypsin 5mg-chymotrypsin 5 mg), a combination of both, or a placebo drug were administered postoperatively. The participants scored pain intensity at different time-intervals using a numerical scale, and passive surveillance of harm was used to detect clinical safety. Age was compared between groups using a one-way analysis of variance test. Pain scores were analyzed using the Kruskal-Wallis and Friedman's tests and, if significant, Dunn's test was used for pairwise comparisons. The chi-square test was used to compare qualitative data, and the significance level was set at P value ≤ .05. RESULTS: All interventions were found to be effective in reducing postoperative pain, and no statistically significant differences were observed between the ibuprofen, trypsin-chymotrypsin, and combination groups. However, all 3 groups differed significantly from the placebo group. The safety profile of the interventions did not differ significantly. CONCLUSIONS: Trypsin-chymotrypsin exhibits comparable efficacy to nonsteroidal anti-inflammatory drugs. No synergistic effects occur when the 2 are used in combination. This is the first randomized controlled trial to assess the effects of proteolytic enzymes on postendodontic pain. TRIAL REGISTRATION: clinicaltrials.gov, Identifier: NCT05479747.

The effect of changing apical foramen diameter on regenerative potential of mature teeth with necrotic pulp and apical periodontitis.

OBJECTIVE: The aim of the present study was to evaluate the regenerative potential of permanent necrotic mature teeth with different apical foramen diameters in comparison to conventional endodontic treatment. METHODS: Pulp necrosis and periapical pathosis were induced in premolars (144 roots) in six mongrel dogs. The infected teeth were divided into six groups; conventional root canal treatment (RCT) group prepared up to apical preparation sizes #F3 ProTaper file, regenerative endodontic therapy (RET) groups; groups RET-F3, RET-F4, and RET-F5 where regenerative endodontic procedures were applied after apical preparation up to sizes #F3, F4, and F5 ProTaper file, respectively, control groups; and positive (P) and negative (N) groups included infected and healthy teeth respectively. Each group (12 teeth with 24 roots each) was further subdivided into two subgroups (6 teeth with 12 roots each) according to the evaluation periods 1 and 3 months; each group was equally randomized in the upper and lower jaws during each evaluation period. RESULTS: The inflammatory cell counts for the RCT group were statistically significantly higher than that of all RET groups at the first period and only significantly higher than RET-F5 at the second period. The enlargement of the apical foramen to #F5 showed no statistically significant difference with #F4 regarding the inflammatory cell count, tissue in-growth inside the root canal, and percentage of bone resorption. The tissue formed after RET was not true pulp tissue and is considered tissue repair with connective tissue, dilated blood vessels, and cementum-like structures.  CONCLUSION: Increasing the apical size diameter was associated with less inflammatory cell count, less percentage of bone resorption, more tissue ingrowth, and more percentage of new hard tissue formation inside root canal. The minimum apical diameter that should be enlarged for RET is 0.4 mm. CLINICAL RELEVANCE: RET could be used as an alternative procedure to RCT for the treatment of mature teeth with necrotic pulp and apical periodontitis.

Application of a new System for Classifying Root and Canal Anatomy in Clinical Practice - Explanation and Elaboration.

Adequate understanding and accurate characterization of normal and unusual root and canal morphology are essential requirements for successful root canal treatment. A new coding system for classifying root and canal morphology, accessory canals and anomalies has been introduced. In addition to technological advances related to experimental studies involving micro-computed tomography, the continuing clinical advances in magnification, illumination, imaging and intra-operative root canal treatment procedures have allowed clinicians to identify an increasingly wide range of anatomical variations in roots and canals in an attempt to achieve more predictable clinical outcomes. This review aims to provide a step-by-step explanation for the clinical application of the new coding system in dental practice, and to describe the anatomical variations in roots and canals for teeth scheduled for root canal treatment.

Histopathological evaluation of different regenerative protocols using Chitosan-based formulations for management of immature non-vital teeth with apical periodontitis: In vivo study.

This study aimed to assess regenerative treatment protocols for maturogenesis of immature teeth with apical periodontitis in dogs. Apical periodontitis was induced in immature premolars of 8 mongrel dogs teeth that were divided into 5 groups; regeneration via blood clotting (REG group); chitosan loaded with demineralised bone matrix (REG-CD group); chitosan loaded with dexamethazone corticosteroid (REG-CC group); and positive and negative control groups. All groups showed comparable apical hard tissue formation and significantly different from the control group. Results also showed decrease in inflammatory tissue reaction, bone resorption and periodontal ligament thickness. Tissue reaction and inflammatory infiltrates were significantly less in REG-CC group compared to others. Other parameters showed no significant difference. In conclusion, regenerative endodontic techniques using chitosan-based formulations have the potential to be used as an alternative for root maturation in teeth with apical periodontitis.

Improved dentin disinfection by combining different-geometry rotary nickel-titanium files in preparing root canals.

OBJECTIVES: This study was to evaluate the antibacterial effect of different instrumentation and irrigation techniques using confocal laser scanning microscopy (CLSM) after root canal inoculation with Enterococcus faecalis (E. faecalis). MATERIALS AND METHODS: Mesiobuccal and mesiolingual canals of extracted mandibular molars were apically enlarged up to a size 25 hand K-file, then autoclaved and inoculated with E. faecalis. The samples were randomly divided into 4 main groups according to the system of instrumentation and irrigation: an XP-endo Shaper (XPS) combined with conventional irrigation (XPS/C) or an XP-endo Finisher (XPF) (XPS/XPF), and iRaCe combined with conventional irrigation (iRaCe/C) or combined with an XPF (iRaCe/XPF). A middle-third sample was taken from each group, and then the bacterial reduction was evaluated using CLSM at a depth of 50 µm inside the dentinal tubules. The ratio of red fluorescence (dead cells) to green-and-red fluorescence (live and dead cells) represented the percentage of bacterial reduction. The data were then statistically analyzed using the Kruskal-Wallis test for comparisons across the groups and the Dunn test was used for pairwise comparisons. RESULTS: The instrumentation and irrigation techniques had a significant effect on bacterial reduction (p < 0.05). The iRaCe/XPF group showed the strongest effect, followed by the XPS/XPF and XPS/C group, while the iRaCe/C group had the weakest effect. CONCLUSIONS: Combining iRaCe with XPF improved its bacterial reduction effect, while combining XPS with XPF did not yield a significant improvement in its ability to reduce bacteria at a depth of 50 µm in the dentinal tubules.

Endodontic Management of a Mandibular First Molar with Unusual Canal Morphology.

A comprehensive knowledge and understanding of root canal anatomical variations are essential for successful root canal treatment. Mandibular molar teeth show considerable variations in their external and internal radicular morphology that require special attention from dental practitioners to provide the best clinical outcomes to the patients. This report aims to present root canal treatment of a mandibular first molar that has six separate root canals (three root canals in the mesial roots and three in the distal roots [236 M3 D3]). This report points out the importance of proper exploration for identifying additional canals in mandibular molars.

Regenerative potential of immature permanent teeth with necrotic pulps after different regenerative protocols.

INTRODUCTION: Regenerative endodontics is a promising alternative treatment for immature teeth with necrotic pulps. The present study was performed to assess the regenerative potential of young permanent immature teeth with necrotic pulp after the following treatment protocols: (1) a mineral trioxide aggregate (MTA) apical plug, (2) the regenerative endodontic protocol (blood clot scaffold), and (3) the regenerative endodontic protocol with a blood clot and an injectable scaffold impregnated with basic fibroblast growth factor. METHODS: Immature necrotic permanent maxillary central incisors (n = 36) of patients 9-13 years old were divided into 3 groups according to the treatment protocol: the MTA group (MTA apical plug), the REG group (regenerative endodontic protocol [blood clot]), and the FGF group (regenerative endodontic protocol [blood clot + injectable scaffold]). Follow-up was done up to 18 months. Standardized radiographs were digitally evaluated for an increase in root length and thickness, a decrease in the apical diameter, and a change in periapical bone density. RESULTS: After a follow-up period of 18 months, most of the cases showed radiographic evidence of periapical healing. Groups 2 and 3 showed a progressive increase in root length and width and a decrease in apical diameter. CONCLUSIONS: The regenerative endodontic procedure allowed the continued development of roots in teeth with necrotic pulps. The use of artificial hydrogel scaffold and basic fibroblast growth factor was not essential for repair.

Expression levels of matrix metalloproteinase-9 and gram-negative bacteria in symptomatic and asymptomatic periapical lesions.

INTRODUCTION: The aim of this study was to test the hypothesis that the expression of matrix metalloproteinase (MMP)-9 is significantly elevated in patients with symptomatic apical periodontitis and to correlate this with the detected amount of gram-negative bacteria. METHODS: Twenty-six patients with periapical lesions involving at least 2 teeth were included in this study. The patients were divided into 2 groups: the symptomatic (SYM) group included 13 patients expressing pain with periapical lesions, and the asymptomatic (ASYM) group included 13 patients expressing no pain. Root canal treatment was performed followed by endodontic surgery and periapical lesion collection. Periapical lesions were serially cut into 4-µ sections. Some sections were processed for histologic examination using hematoxylin-eosin stain. Other sections were processed for immunohistochemical examination. For MMP-9, the area fraction of the positive cells was measured, and the percentage of the MMP-9-immunopositive area to the total area of the microscopic field was calculated. For gram-negative stain cells, the number of cells showing the pink-red color was counted per microscopic field. The Student's t test was used to compare the SYM and ASYM groups. The Pearson correlation coefficient was used to determine a significant correlation between the number of cells and the MMP-9 level. The significance level was set at P ≤ .05. RESULTS: The SYM group showed a statistically significantly higher mean number of gram-negative cells (P = .001) and MMP-9 area percent (P < .001) than the ASYM group. There was a statistically significant positive (r = .927) correlation between the number of gram-negative cells and the MMP-9 area percent (P< .001). CONCLUSIONS: There is good evidence to suspect a significant role of gram-negative bacteria and MMP-9 in symptomatic periapical lesions.

Geometric analysis of root canals prepared by four rotary NiTi shaping systems.

INTRODUCTION: A great number of nickel-titanium (NiTi) rotary systems with noncutting tips, different cross-sections, superior resistance to torsional fracture, varying tapers, and manufacturing method have been introduced to the market. The purpose of this study was to evaluate and compare the effect of 4 rotary NiTi preparation systems, Revo-S (RS; Micro-Mega, Besancon Cedex, France), Twisted file (TF; SybronEndo, Amersfoort, The Netherlands), ProFile GT Series X (GTX; Dentsply, Tulsa Dental Specialties, Tulsa, OK), and ProTaper (PT; Dentsply Maillefer, Ballaigues, Switzerland), on volumetric changes and transportation of curved root canals. METHODS: Forty mesiobuccal canals of mandibular molars with an angle of curvature ranging from 25° to 40° were divided according to the instrument used in canal preparation into 4 groups of 10 samples each: group RS, group TF, group GTX, and group PT. Canals were scanned using an i-CAT CBCT scanner (Imaging Science International, Hatfield, PA) before and after preparation to evaluate the volumetric changes. Root canal transportation and centering ratio were evaluated at 1.3, 2.6, 5.2, and 7.8 mm from the apex. The significance level was set at P ≤ .05. RESULTS: The PT system removed a significantly higher amount of dentin than the other systems (P = .025). At the 1.3-mm level, there was no significant difference in canal transportation and centering ratio among the groups. However, at the other levels, TF maintained the original canal curvature recording significantly the least degree of canal transportation as well as the highest mean centering ratio. CONCLUSIONS: The TF system showed superior shaping ability in curved canals. Revo-S and GTX were better than ProTaper regarding both canal transportation and centering ability.

The effect of acidity on dislodgment resistance of mineral trioxide aggregate and bioaggregate in furcation perforations: an in vitro comparative study.

INTRODUCTION: The aim of this study was to compare the effect of acidic environment on the dislodgement resistance of mineral trioxide aggregate (MTA) and Bioaggregate (Innovative BioCeramix, Vancouver, Canada) when used as perforation repair materials. METHODS: Eighty, human, mandibular molars were used. Perforations were made in the furcation of each molar and enlarged to #4 Pesso drills. After perforation repair, specimens of each material were randomly divided into 4 groups (n = 10) according to storage media and time: group A: phosphate-buffered saline (PBS) (pH = 7.4) for 4 days, group B: acetic acid (pH = 5.4) for 4 days, group C: PBS for 34 days, and group D: acetic acid (pH = 5.4) for 4 days followed by exposure to PBS for 30 days. Dislodgment resistance was then measured using a universal testing machine, and then the specimens were vertically split to examine the perforated dentin wall using scanning electron microscopy. RESULTS: MTA resisted dislodgement more efficiently than BA after 4 days in PBS (P < .05). The dislodgment resistance of MTA was significantly reduced (P < .05) after exposure to acetic acid, whereas BA was not affected (P > .05). There was an increase in the dislodgment resistance with the increase in the storage time to 34 days (P < .01). After 34 days, there was a statistically significant difference among groups; the MTA D group had significantly the highest bond strength, and the BA D group D had the lowest (P < .05). CONCLUSIONS: MTA is more influenced by acidic pH than BA. Storage for 30 days in PBS can reverse the affected bond of MTA by the acidic environment.

Efficacy of different final irrigation activation techniques on smear layer removal.

INTRODUCTION: Different techniques and irrigant delivery devices have been proposed to increase the flow and distribution of irrigating solutions within the root canal system. The aim of this study was to compare smear layer removal after final irrigant activation with apical negative pressure (ANP), manual dynamic agitation (MDA), and passive ultrasonic irrigation (PUI). METHODS: Forty single-rooted human mandibular premolars were decoronated to a standardized length of 16 mm. They were cleaned and shaped by using ProTaper system to size F4 and NaOCl 2.5%. The specimens were divided into 4 equal groups (n = 10) according to the final irrigation activation technique: group 1, passive irrigation (PI); group 2, apical negative pressure (ANP) (EndoVac); group 3, manual dynamic activation (MDA); and group 4, passive ultrasonic irrigation (PUI). Samples were split longitudinally and examined under scanning electron microscope for smear layer presence. RESULTS: PI and PUI had the highest smear scores, with no significant differences between them. This was followed by MDA and finally ANP, which showed the statistically significant lowest mean score at P ≤ .05. CONCLUSIONS: Final irrigant activation with ANP and MDA resulted in better removal of the smear layer than with PUI or PI.

The effect of different irrigating solutions on bond strength of two root canal-filling systems.

The bond strength of ActiV GP root canal filling system and gutta-percha/AH plus sealer when used after final rinse with different irrigation protocols was evaluated in this study. Forty roots were randomly divided into four groups (n = 10) according to the final irrigation regimen: group 1, 5 mL 17% EDTA; group 2, 5 mL 17% EDTA followed by 5 mL 2% chlorhexidine gluconate (CHX); group 3, 5 mL MTAD; and group 4, 5 mL MTAD followed by 5 mL 2% CHX. Each group was further subdivided into two subgroups (n = 5): in subgroup a, the root canals were filled using warm gutta-percha and AH plus sealer, and in subgroup b, the root canals were filled using the ActiV GP obturation system. Two-millimeter thick horizontal sections from the coronal and midthirds of each root were sliced for the push-out bond strength measurement. EDTA/CHX/ActiV GP (2.46 +/- 1.02 MPa) yielded significantly the highest mean bond strength value. The significantly lowest bond strength was recorded for EDTA/ActiV GP (1.12 +/- 0.72 MPa). It was concluded that the bond strength of ActiV GP was improved by using 2% CHX in the final irrigation after 17% EDTA, whereas CHX did not enhance the effect of MTAD on the bond strength of the material. The bond strength of gutta-percha/AH plus was adversely affected by MTAD and MTAD/CHX.

ProRoot MTA, MTA-Angelus and IRM used to repair large furcation perforations: sealability study.

The ability of two mineral trioxide aggregate (MTA) compounds and Intermediate Restorative Material (IRM) to seal large furcation perforations were evaluated using a dye-extraction leakage method. The furcation perforations were repaired with and without the use of internal matrix before placement of repair material. Eighty extracted human mandibular first molars were divided into positive (n = 10), negative (n = 10), and three experimental groups (n = 20) according to the repair material used. Each experimental group was divided into two subgroups (n = 10) according to whether internal matrix was used or not. Dye leakage was tested from an orthograde direction, and dye extraction was performed using full concentration nitric acid. Dye absorbance was measured at 550 nm using spectrophotometer. ProRoot MTA (Maillfer, Dentsply, Switzerland) with and without internal matrix and MTA-Angelus (Angelus, Londrina, PR, Brazil) with internal matrix showed the least dye absorbance. IRM (Caulk, Dentsply, Milford, DE) without internal matrix showed the highest dye absorbance. IRM with internal matrix and MTA-Angelus without internal matrix had insignificant difference and came at intermediate level between the other groups.

Ultrasonic vibration: temperature rise on external root surface during broken instrument removal.

The effect of 2 ultrasonic tips and power settings on temperature rise of external root surface was investigated during ultrasonic vibration of intracanal broken instruments. Thirty maxillary human central incisors had lingual coronal access. The apical 5 mm of size 40 K-files was separated at apical region. Two thermocouples connected to digital thermometer were attached to external root surface to measure temperature rise. Central incisors were divided into 3 equal groups: group 1 in which Satelec ET 40 ultrasonic tip at power 1 was used, group 2 in which ET 40 at power 5 was used, and group 3 in which CPR 5 ultrasonic tip at power 1 was used. Ultrasonic vibration without coolant was activated for 2 minutes, and temperature rise was recorded at 1 and 2 minutes. At 1 minute, CPR 5 and ET 40 at power 1 showed statistically significant less temperature rise. CPR 5 demonstrated lower temperature rise compared with ET 40 when used for 2 minutes. ET 40 showed less temperature at power 1 compared with power 5. Significant increase in temperature from 1 minute to 2 minutes was observed in all groups.