Root Canal Wall Dentin Research Articles

Non-surgical management of simultaneous occurrence of internal root resorption and calcific metamorphosis: A case report

Internal resorption and calcific metamorphosis are two sequelae of pulpal necrosis after traumatic injuries like concussion and luxation injuries. After traumatic injury, the pulp may become completely necrosed followed by calcification of the entire root canal by the activity of odontoblastic cells. In some other cases, partial necrosis of the pulp tissue with overstimulation of odontoclastic cells and resorption of the root canal dentinal walls may happened. Commonly any of the cells become active and one of the sequelae may will continue. Rarely these two conditions will happen together. In this particular case report with simultaneous occurrence of these two conditions with symptomatic periapical abscess.

Comparative Assessment of The Fracture Resistance of Teeth Instrumented by Two Different Nickel Titanium Rotary Systems

Aim: This study aimed to compare the fracture resistance exhibited by roots on instrumentation using two endodontic rotary systems: SANI S3 and EdgeEndo X7 rotary file systems. Materials and Methods: Sixty recently extracted human mandibular premolars comprising single root canals were selected in this study. All specimens were decoronated and mounted perpendicularly in self-cure acrylic resin blocks exposing 6 mm of the roots out of the acrylic resin blocks. The specimens were divided into two experimental groups, according to NiTi rotary systems used and one control group (n = 20). After instrumentation, the specimens of both experimental groups were then filled using master Gutta-percha cones size 35 (0.04 taper) and obturation was done using continuous wave compaction technique. The specimens were kept at 37 °C and 100% humidity for 2 weeks to allow complete setting of the sealer. Root fracture resistance was assessed using a universal testing machine (Instron) and the amount of load necessary for root fracture was recorded in Newtons (N). Statistics: Data were collected, tabulated and statistically analyzed using one-way ANOVA test and Tukey’s posthoc test. Results: Group C (control) exhibited the highest mean fracture force (357.13 ± 20.61) while group A (SANI S3) showed the lowest mean fracture force (192.60 ± 22.73). One-way ANOVA test showed statistically significant differences between tested groups. Regarding inter-group comparisons using Tukey’s test, there was a significant statistical difference between groups (A and B) and between groups (A and C). Furthermore, there was a statistically significant difference between groups (B and C). (P?0.05) Conclusion: 1-Root canal instrumentation with NiTi rotary files possessed a negative impact on roots and higher risks of root fractures compared to intact unprepared roots. 2-Design of NiTi files with improved cutting efficiency could diminish the risk of crack formation in root canal dentinal walls.

The Biological and Mechanical Effect of Using Different Irrigation Methods on the Bond Strength of Bioceramic Sealer to Root Dentin Walls.

ObjectivesThis study aimed to evaluate the biological and mechanical effect of different irrigation methods on the bond strength of Bioceramic (BC) sealer to root canal dentin walls.Material and MethodsForty-Five single-rooted teeth were decoronated and then prepared using rotary instrumentation. Teeth were randomly divided into three groups. Group 1: using the conventional syringe method; Group 2: using the ultrasonic (US) activation method; and Group 3: using the Nd:YAG laser activation method. The BC sealer (TotalFill® BC Sealer™, FKG Dentaire, Switzerland) was used for obturation according to the manufacturer’s recommendation. The bond strength was evaluated using the push-out test, and the adaptation of the sealer/dentin interface was assessed using Scanning Electron Microscope (SEM). Data were analyzed by Welch’s ANOVA analysis of variance and Games-Howell for pairwise comparison. The level of statistical significance was set at 95% (p-value ≤ 0.05).ResultsThe push-out bond strength values of the Nd:YAG (6.46 ± 0.5) laser group were statistically significant than both conventional (3.33 ± 1.8) and US groups (4.21 ± 2.2). The mean gaps that were formed between the root walls and GP/BS sealer interface were statistically significant only between the Nd:YAG laser group (25.54 ± 13.8) compared to both conventional (62.00 ± 15.3) and US groups (58.82 ± 23.8) (p ≤0.05). No significant difference was found between the conventional and US groups in both rested parameters (p >0.05).ConclusionThe method protocol of RC system irrigation affects the adhesion and bond strength of BS sealers to the root canal dentin walls.

Apexification and dentinal wall reinforcement using Biodentine and glass fiber post

A 21-year-old male patient reported with chief complaint of pain in the upper front teeth. Clinical examination revealed tooth fracture in teeth # 11, 21, and prior attempted endodontic treatment. The radiographic examination revealed periapical radiolucency in relation to upper central incisors with thinning of dentinal walls. The upper left central incisor had grossly diminished root canal dentin walls with immature apex, whereas the upper right central incisor had moderate loss of dentin from the root canal wall with an open apex. Hence, it was decided to extract the upper left central incisor, whereas apexification and root canal dentin wall reinforcement with Biodentine were carried out for the upper right central incisor. The patient was asymptomatic at 1-, 4-, and 6-month follow-up visits.

Effect of different laser types on bonding strength of CAD/CAM-customized zirconia post to root canal dentin: an experimental study.

In clinical dentistry, the strength of bonding zirconia posts to root canal dentinal walls currently needs enhancement, and laser application can be an important contribution owing to its features that accommodate adjustable modifications on dental materials. Herein, the effect of different laser treatments applied to dentin surfaces on the strength of bonding zirconia posts to root canal dentinal walls is evaluated by using the pull-out bond strength test in a laboratory setting. A total of 40 single-rooted permanent mandibular premolar teeth that were freshly extracted were used here. The root canal preparation steps were performed using the crown-down technique. Custom-made zirconia posts were produced using CAD/CAM technology. Prior to the application of resin cement, the internal surfaces of the root canals were irradiated using Nd:YAG, Er:YAG, and KTP lasers. Pull-out tests were performed on each specimen by using a universal testing machine. One-way analysis of variance and Tukey post hoc tests were used to compare the pull-out bond strength data. The bond strengths of the laser-treated specimens were greater than those of the untreated controls (p < 0.05). While the value of the pull-out bond strength after Nd:YAG laser treatment was significantly higher than the values obtained after the applications of the Er:YAG and KTP lasers (p < 0.05), the pull-out bond strength after Er:YAG laser treatment was considerably greater than that after KTP laser treatment (p < 0.05). The bond strength between the root canal dentin and the CAD/CAM custom-made zirconia post was improved upon using all the laser modalities in current laboratory settings, among which, application of the Nd:YAG laser was the most successful.

Evaluation of Debris Extrusion and Smear Layer Production Following Preparation Using Three Different Nickel Titanium Files

Objectives: The aim of this study was to compare the amount of apically extruded debris andthe patterns of smear layer formation following the preparation of root canals in extracted humanteeth using ProTaper Next, Twisted file, and a reciprocating single-file system.Material and Methods: Forty-five freshly extracted human single-rooted maxillary incisorswere divided into 3 groups (n=15) then instrumented using Protaper Next, Twisted files, andReciproc. The extruded debris were collected in a pre-weighed Eppendorf tubes. The tubes werestored in an incubator at 70 °C for 2 days before weighing the dry debris using analytical balance.The debris weight was determined by subtracting the initial weight from the final weight. Rootsamples were splitted longitudinally into two halves by making grooves then root halves (cervical,middle and apical) thirds were examined using Environmental Scanning Electron MicroscopeESEM (FEI Quanta 250 FEG, Berlin, Germany) at ×1500 magnification. All the data were subjectedto statistical analysis using Chi-squared, Fisher`s Extract.Results: The three tested rotary nickel titanium files produced comparable amount of debrisextrusion and smear layer patterns covering the root canal dentin walls. Apical third showed theheaviest accumulation of smear layer.

Root canals dentinal wall structure after photodynamic exposure

The aim of the study was to assess root canal dentinal walls structure after photodynamic exposure with the use of 0.5% photoditazine. A root canal dentin of 46 single root intact teeth removed for orthodontic indications was examined by scanning electron microscope JEOL JSM-6510 (Japan). Microphotographs of the root canal wall were obtained in the orifice, central and apical parts under×2000 magnification. It was found that photoactivation of 0.5% gel photoditazine by a light source, laser or diode, with a wavelength of 635-660 nm and a power of 150-200 mW is an effective technique for removing the smear layer of the root canal wall, which facilitates the maximum opening of the dentinal tubules to a depth of 2-3 μm. The best result (the maximum number of open dentinal tubules, the absence of a smear layer) is observed with 3 min photoditazine exposure and 2 min of laser exposure. The method can be proposed as an alternative supplement to the conventional root canals irrigation.

Using erbium-doped yttrium aluminum garnet laser irradiation in different energy output levels versus ultrasonic in removal of root canal filling materials in endodontic retreatment.

Objectives:The objective of this study was to evaluate the efficacy of erbium-doped yttrium aluminum garnet (Er:YAG) laser irradiation in different energy outputs versus ultrasonic in gutta-percha removal during the endodontic retreatment.Materials and Methods:A total of 21 extracted human lower premolars were divided into three groups (n = 7). Following the standardized preparation of the root canals with Wave One Rotary system and obturation with gutta-percha: Group I was treated with ultrasonic, Group II by Er:YAG laser with 40 mJ/Pulse, and Group III by Er:YAG laser with 50 mJ/Pulse for the removal of gutta-percha from the canals. Two extra teeth were treated by Er:YAG laser with 135 mJ/Pulse as control group. For all groups, time for gutta-percha removal was recorded. Samples were then splited into two halves and tested by scanning electron microscope and stereomicroscopic evaluation under different magnification power to observe the efficacy of each method used in the removal of gutta-percha.Results:Statistical analysis of Kruskal–Wallis suggested that there are significant difference between the groups in relation to removal time (P < 0.05) and 2 × 2 Mann–Whitney U-test among the groups revealed that there is no significant difference between 40 and 50 mJ laser outputs (P > 0.05), but ultrasonic versus 40 and/or 50 mJ laser outputs were significantly different (P < 0.05).Conclusions:Er:YAG laser beam was not so efficient when compared to ultrasonic to reach the deeper parts of the canals as it was asserted, thermal side effects and burning damages were observed on the root canal dentinal walls. Moreover, the delivery system was not flexible enough to compensate the curvature of the canal system even though we used more straight canals as the sample ones as well as more time-consuming than the ultrasonic and more clinical time, rendering it to be less efficient in the removal of the obturation material during endodontic retreatment procedures.

Effect of Imidazolium-Based Silver Nanoparticles on Root Dentin Roughness in Comparison with Three Common Root Canal Irrigants.

Introduction:The aim of this study was to evaluate the effect of a nanosilver-based irrigant on dentin roughness in comparison with three commonly used root canal irrigation solutions. Methods and Materials:Three common irrigants including 5.25% sodium hypochlorite (NaOCl), 17% ethylenediaminetetraacetic acid (EDTA) and 2% chlorhexidine (CHX) and also an imidazolium-based silver nanoparticle solution (ImSNP) (5.7×10 -8 mol/L), were used. Distilled water was used as control. Roots of 25 human anterior teeth were sectioned longitudinally to obtain 50 dentin samples. Roughness values were evaluated by atomic force microscopy analysis on 5 groups (n=10) after each group was treated in one of the tested irrigant solutions for 10 min. Values were statistically analyzed by One-way analysis of variance, followed by a post hoc Tukey’s test for pair-wise comparison.Results:Dentin roughness significantly increased from 95.82 nm (control) to 136.02 nm, 187.07 nm, 142.29 nm and 150.92 nm with NaOCl, CHX, ImSNP and EDTA, respectively. CHX demonstrated a significantly higher roughness value compared to the other tested irrigants while no significant differences were seen in NaOCl, ImSNP and EDTA groups (P>0.242). Conclusion:ImSNP affected the physicochemical properties of dentin and raised its surface roughness; thus, this irrigant could impact bacterial and restorative material adhesion to root canal dentin walls.

Effect of imidazolium based silver nanoparticle irrigant on root canal dentin roughness in comparison with three common irrigants

Introduction : The aim of this study is to evaluate the effect of a newly introduced nanosilver based irrigant on dentin roughness in comparison with three commonly used root canal irrigants. Material and methods : Irrigants tested were: NaOCl 5.25%, EDTA 17%, CHX 2% and newly introduced imidazolium-based silver nanoparticle (Im AgNP) irrigant at 5.8×10 -8 mol/L. Distilled water was used as control. Roots of 25 human anterior teeth were sectioned longitudinally to obtain 50 dentin samples. Roughness values were evaluated by Atomic Force Microscopy analysis on 5 groups of 10 samples after each group were treated in one of the tested irrigant solutions for 10 minutes. Results: Dentin roughness significantly increased from 95.82 nm (control) to 136.02 nm, 187.07 nm, 142.29 nm and 150.92 nm by NaOCl, CHX, Im AgNP irrigant and EDTA respectively. CHX demonstrated a significantly higher roughness value compared to the other irrigants tested while no significant differences were seen in NaOCl, Im AgNP irrigant and EDTA groups. (P>0.05) Conclusions: Im AgNP irrigant affect physicochemical property of dentin and raised its surface roughness, thus, this irrigant could impact bacterial and restorative material adhesion to root canal dentin walls.

Effect of double antibiotic and calcium hydroxide pastes on dislodgement resistance of an epoxy resin-based and two calcium silicate-based root canal sealers.

The purpose of the present study was to determine the dislodgement resistance of AH Plus, MTA Fillapex, and Total Fill BC sealer to root canal dentin walls following placement of calcium hydroxide (CH) or double antibiotic paste (DAP) medicaments. Root canals of 90 single-rooted human mandibular premolar teeth were instrumented with Reciproc rotary instruments to a size R50. The teeth were randomly divided into two experimental groups: those receiving an intracanal medicament with either CH or DAP and a control group (n=30). After 3weeks, the medicaments were removed by irrigation with 5mL of 2.5% NaOCl, 5mL 17% EDTA, and 5mL distilled water under sonic agitation. Each group was then subdivided into three subgroups (n=10), and the canals were filled with either AH Plus, MTA Fillapex, or Total Fill BC sealer. After 1week, a push-out test was applied to the specimens and the results were analyzed using one-way analysis of variance (ANOVA) and post hoc Tamhane's tests. Regardless of the type of intracanal medicament used, Total Fill BC Sealer and MTA Fillapex showed the highest and lowest bond strength, respectively (P<0.05). The use or absence of medicaments did not significantly affect the dislodgment resistance of root canal fillings (P>0.05). Prior CH placement improved dislodgement resistance of all sealers without statistical difference (P>0.05). Adhesive failure between core and sealer was the most frequent failure mode. Prior application of CH or DAP did not significantly affect the adhesion of the AH Plus, MTA Fillapex, and Total Fill BC Sealers. There is a little information about the influence of antibiotic medicaments on the bond strength of root canal sealer. These findings suggest that the use of DAP does not affect the adhesion strength of AH Plus, MTA Fillapex, and Total Fill BC Sealers.

Comparison Between Different Endodontic Irrigating Protocols In Smear Layer Removal From Radicular Dentin

The aim of our study was to measure the cleaning efficiency of irrigating solutions used during endodontic treatment regarding smear layer removal from the root canal dentin walls. Ethylenediaminotetraacetic acid (EDTA) 17%, citric acid (CA) 10% and sodium hypochlorite (NaOCl) 2,5 % solutions were tested as final irrigating solutions. The study was conducted on extracted teeth, divided in four groups according to the irrigation protocol used. The specimens were analyzed by scanning electron microscopy and the amount of smear layer present at apical, middle and coronal level was recorded, based on a scoring system. Data were statistically analyzed using Kruskal-Wallis and Friedman test and the level of significance was set at p&lt;0.05. In the coronal and middle segments of dental roots we noticed no statistically significant difference between EDTA and CA in smear layer removing capacity. Final irrigation with 17% EDTA proved to be more efficient than 10% CA and 2,5% NaOCl in smear layer removal at apical level of the root canal, with p&lt;0.05 (p=0.042), which is an important area for disinfection in endodontic treatment.

THE EFFECT OF THREE ROOT CANAL SEALERS TO ROOT CANAL DENTIN WALLS

THE EFFECT OF THREE ROOT CANAL SEALERS TO ROOT CANAL DENTIN WALLS

Comparative Scanning Electron Microscopy Evaluation of Smear Layer Removal with 17% Ethylenediaminetetraacetic Acid, 10% Citric Acid and Newer Irrigant QMix: In Vitro Study

Aim: The aim of this study was to compare the effectiveness of 17% ethylenediaminetetraacetic acid (EDTA) with that of 10% citric acid and newer irrigant QMix in the removal of smear layer from root canal wall dentin. Materials and Methods: Twenty single-rooted teeth were accessed and instrumented with crown down technique up to protaper F3. Between each instrument used, the canals were irrigated with 1 ml of 5% sodium hypochlorite (NaOCl). After instrumentation, the teeth were irrigated with distilled water and then divided into four groups according to the different surface treatment with different irrigants. The irrigants used were 1% NaOCl, 17% EDTA, 10% citric acid, and newer irrigant QMix. The samples were prepared and observed by means of scanning electron microscopy. Three photomicrographs (Χ2000) were recorded for each sample regarding the apical, middle, and cervical thirds. A score system described by Takeda et al. was used to evaluate the images.

Effects of dentin surface treatments including Er,Cr:YSGG laser irradiation with different intensities on the push-out bond strength of the glass fiber posts to root dentin

Objective. Intra-canal post systems are commonly used to restore root-filled teeth. Bond strengths of the posts can be affected by various surface treatments of the post or the dentin. The aim of this study was to evaluate the effects of dentin surface treatments including erbium-chromium; yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser irradiation with different intensities on the push-out bond strength of the glass fiber posts to root dentin. Materials and methods. Forty single-rooted human maxillary incisors were filled and post spaces were prepared. After these procedures, the specimens were divided randomly into four groups according to the dentin surface treatments, as follows: (i) untreated surface (control), (ii) 1W Er,Cr:YSGG laser application, (iii) 2W Er,Cr:YSGG laser application and (iv) 3W Er,Cr:YSGG laser application. Then the posts were cemented into the root canals using dual-cured resin cement. Bonded specimens were cut into 1-mm-thick slices and push-out tests were performed using a universal testing device. All specimens were loaded until fracture and the failure modes were evaluated with a stereomicroscope at 32× magnification. Representative specimens were analyzed by scanning electron microscopy. Data were analyzed using a one-way ANOVA, Tukey and Wilcoxon tests. Results. The bond strength values ranged from 3.22–4.68 MPa. There were no statistically significant differences among the groups, regardless of the different levels. The coronal and middle levels of the post space had significantly higher bond strength values compared with the apical level (p < 0.05). Conclusion. Er,Cr:YSGG laser irradiation with different intensities did not increase the bond strength of the fiber posts to the root canal dentin walls.

Bond strength of fiber-reinforced posts to deproteinized root canal dentin.

This study evaluated the push-out bond strength of cemented fiber posts after deproteinization of root canal dentin walls with NaOCl. The effect of the application of an antioxidant solution (sodium ascorbate) was also evaluated. A three-step etch-and-rinse (Scotch-bond - 3M Espe) and a one-step self-etching adhesive (Xeno III - Dentsply Caulk) were evaluated. Thirty bovine incisor roots were divided into 3 groups: a. Irrigation with physiologic solution (control). b. Deproteinization with 10 minutes irrigation of 5% NaOCl. c. Deproteinization with NaOCl followed by 10 minutes irrigation with 10% ascorbic acid. Fiber posts were cemented with a dual-cured cement (Rely X ARC - 3M ESPE). The push-out bond strength was evaluated after 24 hours of storage in distilled water. The data were analyzed with three-way ANOVA, one-way ANOVA and Tukey's test (α = 0.05). There were significant differences between groups (p < 0.05). The bond strength of Scotchbond was not influenced by the deproteinization. Xeno III showed a decrease in bond strength when deproteinized with 5% NaOCl (p < 0.05). For Xeno III, the subsequent irrigation with ascorbic acid was able to reverse the effect of the deproteinization. Considering the radicular thirds, the bond strength varied in the sequence-apical < middle < coronal. Only the all-in-one adhesive was influenced by the deproteinization. Considering the respective control groups, both systems showed similar bond strength results. The decreased bond strength of the self-etching adhesive following deproteinization seams to be related to the oxidant effect of the NaOCl solution and the subsequent irrigation with ascorbic acid was able to reverse the effect of the deproteinization.

Efficacy of different treatments of root canal walls on the pull-out bond strength of the fiber posts

The aim of this study was to evaluate the efficacy of different irrigation protocols, including laser, on the retention of the fiber-reinforced composite posts to root canal dentinal walls using pull-out tests. Root canals of 60 single-rooted human teeth were filled and post spaces were prepared. Finally, specimens were divided randomly into five groups, each consisting of 12 specimens as follows: 5% NaOCl (control group), 17% EDTA, ultrasonic with 17% EDTA, single 1.5-W Er:YAG laser application, and the combined use of Er:YAG laser and 17% EDTA. After the root canal procedures, fiber posts were cemented to the root canal. Pull-out tests were performed using a universal testing machine at a crosshead speed of 2 mm/min. The data were analyzed using a one-way ANOVA and Bonferroni post hoc test (p = 0.05). Irradiation by the Er:YAG laser with/without EDTA positively affected the pull-out bond strength (p < 0.001). The pull-out strength was significantly higher in the ultrasonic group than that of the single irrigation with NaOCl or EDTA (p < 0.001). Er:YAG laser irradiation with/without EDTA enhanced the bond strength of fiber posts to root canal dentin walls. Additionally, ultrasonic-EDTA combination increased the bond strength.

Nano-scratch behavior of human root canal wall dentin lubricated with EDTA pastes

The present study evaluated the wear behavior of human root canal dentin and the lubricating effect of EDTA pastes using nano-scratch tests in vitro. The human root canal wall specimens were tested under a constant load of 80mN and the lubricating effect of different concentrations of EDTA pastes were analyzed. EDTA lubrication strengthened wear effect on the root canal dentin. The application of EDTA paste decreased the microhardness and wear resistance of root canal wall. The wear mechanism of root canal dentin changed from plastic deformation to a combination of deformation, delamination, and microcrack propagation because of the strengthening effect of EDTA pastes.

Quantitative Analysis of the Effect of Irrigant Solution Sequences on Dentin Erosion

Objective The purpose of the study was to examine the level of erosion on root canal wall dentin caused by immersion in different irrigant solutions in alternative sequences. Methods Dentin specimens from teeth with one root canal were instrumented and randomly divided into five groups. Each group was subjected to 17% EDTA, 17% ethyleneglycoltetraacetic acid (EGTA), or 10% citric acid (CA) and 5.25% sodium hypochlorite (NaOCl) varying the time of irrigant exposure and the order of the irrigants. The specimens were examined by scanning electron microscopy (SEM), and randomized digital images of the dentin surface were taken. The area of tubule openings was measured by a semiautomatic method. Results No erosion was detected when demineralizing agents were used as a final rinse after NaOCl. However, the erosion of peritubular and intertubular dentin was detected when EDTA, EGTA, or CA were used first followed by 5.25% NaOCl ( P < .05), and an increase over 100% in the area of dentin tubule openings was measured ( P < .01). Conclusions NaOCl used as a final irrigant solution after demineralization agents causes marked erosion of root canal dentin.

Calcium hydroxide induced apexification with apical root development: a clinical case report

To report the induction of apical root development by calcium hydroxide in teeth with pulp necrosis and periapical radiolucency. A 10-year-old male patient was admitted to the clinic complaining of an intense pain and oedema on the anterior facial region, compatible with an acute dentoalveolar abscess. There was a previous history of dental trauma; only tooth 11 was negative to pulp sensitivity tests. Radiographically, tooth 11 exhibited incomplete root formation, characterized by a wide root canal, thin and fragile dentinal walls, and an extensive, divergent foraminal opening associated with an apical radiolucency. The first appointment focused on urgent local and systemic treatment. Apexification treatment commenced at the second session after 7 days, by means of chemo-mechanical debridement throughout the entire root canal, using K-files and irrigation with a 2.5% sodium hypochlorite solution. Subsequently, a calcium hydroxide paste was applied and changed four times over 8 months, when radiographic examination revealed complete closure of the foraminal opening, resulting in resolution of the periapical radiolucency and associated with 5 mm of additional root development. The root canal was filled by thermomechanical compaction of gutta-percha and sealer. A 3-year follow-up revealed normal periapical tissues and the absence of symptoms. * In young patients, dental trauma may cause pulp necrosis and arrest of root formation. * Under certain circumstances, chemo-mechanical debridement, including the use of a calcium hydroxide paste, is a valid alternative to mineral trioxide aggregate and or surgery for root-end closure. * In teeth with incompletely formed roots associated with periapical lesions, calcium hydroxide can induce periapical repair through the closure of the foramen and apical root development.