A Comparative Evaluation of the Cleaning Efficacy of Five Different Root Canal Irrigation Devices: A Histological Study.

OBJECTIVES: This study is aimed to evaluate the cleaning efficacy of five different irrigation systems as SonicMax, RinsEndo, EndoVac, passive ultrasonic irrigation (PUI), and manual needle irrigation (MNI) to histologically evaluate the presence of organic structures and the penetration of irrigation solution. MATERIALS AND METHODS: Forty-two single-rooted, extracted human mandibular premolars were used in the study. Each tooth was decoronated at the cementoenamel junction and the root canals were instrumented using ProTaper rotary instruments in a crown-down manner. The specimens were randomly divided into five experimental groups (n = 7) Group (1) SonicMax, group (2) RinsEndo,group (3) EndoVac, group (4) PUI, group (5) MNI, and the control groups (n = 7). Each system used 2.5% sodium hypochlorite (NaOCl), 17% ethylenediamine tetraacetic acid (EDTA), and 2.5% NaOCl, respectively, in the experimental groups. The control group did not receive any final irrigation.The measurements were analyzed by employing two-way analysis of variance multivariate results to show significant differences between the length of the dentin tubules in the apical, middle, and coronal of the six groups. The post-hoc test was used when groups were compared by pairs. RESULTS: The results of this study indicate that among the five groups, the RinsEndo and EndoVac were found to be most effective in the cleaning of root canals. The RinsEndo shows highly significant results in the cleaning efficiency of the coronal and middle parts compared with the other groups. The cleaning efficiency in the apical area was the same for RinsEndo and EndoVac. CONCLUSION: The result of our study indicates that RinsEndo and EndoVac may be more effective in clinical practice.

Effectiveness of a novel chelating agent in removing calcium hydroxide using conventional and passive ultrasonic irrigation techniques.

Background: The present in vitro study aimed to compare the efficacy of a 25% copolymer of acrylic acid and maleic acid [poly(AA-co-MA)] and 17% of ethylenediaminetetraacetic acid (EDTA) in removing calcium hydroxide (CH) from root canals using the master apical file (MAF) and passive ultrasonic irrigation (PUI). Material and Methods: Fifty-eight teeth were dressed with CH. After 10 days, CH was removed using MAF+EDTA, MAF+poly(AA-co-MA), PUI+EDTA, and PUI+poly (AA-co-MA) (n=12). Ten teeth were used as controls. Residual CH was evaluated using a four-grade scoring system. Data analysis was performed using the Mann-Whitney U, Friedman, and Dunn-Bonferroni tests. Results: In the MAF and PUI groups, there was no significant difference in the CH scores between EDTA and Poly(AA-co-MA) (p<0.083). Although EDTA and poly(AA-co-MA) had lower CH scores when used with PUI, no significant difference was found between the two agents (p<0.083). Conclusions: Poly(AA-co-MA) did not remove significantly more CH than EDTA when used with MAF or PUI. Key words:Calcium hydroxide, Ethylenediaminetetraacetic acid, Acrylic acid, Maleic acid.

Evaluation of different irrigation techniques on dentin erosion and smear layer removal: A scanning electron microscopy study.

Aim: The purpose of the present study is to evaluate the effectiveness of different irrigation techniques EndoVac, RinsEndo, Canal CleanMax (CCMax), SonicMax, Passive Ultrasonic Irrigation (PUI), and Manual Needle Irrigation (MNI) on dentin erosion and smear layer removal using Scanning electron microscopy (SEM). Materials and Methods: Seventy extracted single-rooted teeth were instrumented with ProTaper rotary instruments. The roots were randomly divided into six experimental groups (n = 10): EndoVac, RinsEndo, CCMax, SonicMax, PUI, and MNI. Final irrigation was performed with NaOCl followed by ethylenediaminetetraacetic acid and NaOCl. Six roots served as control and were irrigated with only NaOCl. Next, the roots were sectioned in a buccolingual direction and the halves were examined by SEM. Smear layer and erosion scores were recorded in the cervical, middle and apical third of the roots. Data analysis was performed using the Kruskal-Wallis and Mann-Whitney U-tests with a level of significance α = 0.05. Results: PUI had the greatest amount of smear layer compared to other groups (P < 0.001). However, SonicMax had the greatest degree of erosion compared to RinsEndo, MNI, PUI, and EndoVac groups (P < 0.001) and CCMax group (P < 0.05). Conclusions: RinsEndo and EndoVac techniques left the least amount of smear layer while causing erosion the least compared to CCMax, PUI, and MNI techniques.

Debris and Smear Layer Removal from Oval Root Canals Comparing XP-Endo Finisher, EndoActivator, and Manual Irrigation: A SEM Evaluation.

OBJECTIVE: This study aimed to assess and compare XP-Endo Finisher (XP) cleaning efficiency with respect to the amount of remaining debris and smear layer versus Max-I-Probe needle (CI), EndoActivator device (EA), and combination of XP-Endo Finisher file with EndoActivator device (XP+EA) in oval root canals. MATERIALS AND METHODS: This in vitro study was performed on 36 extracted single root/canal mandibular premolars. Radiographic images were taken in buccolingual and mesiodistal projections to evaluate the shape of the root canal and determine whether it met exclusion criteria. All teeth were decoronated and prepared using Reciproc (R40). The samples were divided randomly into four groups: CI, EA, XP, and XP + EA. The root canals were irrigated with 5 mL of 17% EDTA and 2.5% NaOCl, respectively. Apart from the CI group, both solutions were activated by using the tested techniques for 1 minute.The teeth were split longitudinally, and the best visible identified sections of the roots were used as the representing samples for scanning electron microscope (SEM) evaluation. Each half was divided into the following three parts: 1 mm from the anatomic apex and a standardized photomicrograph with 500x and 1500x magnifications for debris and smear layer were obtained. A five-grade scoring system was utilized to quantify the results at the coronal, middle, and apical regions. Statistical analysis was performed by using the Kruskal-Wallis and Mann-Whitney U tests. RESULTS: Group differences in debris and smear layer scores were found statistically significant for all locations as well as for overall assessment, except for the coronal third. Intragroup comparison of debris and smear layer in CI, EA, and XP had the minimum score at the middle third, with no significant difference compared with the coronal and apical thirds. XP + EA had less debris and smear layer score at the coronal third, significantly different from apical third.CI and EA had less debris and smear layer compared with XP and XP + EA at all locations with a significant difference at the middle and apical third (p < 0.05). CONCLUSION: EA and CI showed less debris and smear layer than XP and XP + EA in the middle and apical third. The use of the XP in conjunction with the present irrigation protocol failed to have debris-free dentin surface in the apical portion of most of the root canals.

Optimization of scanning electron microscope technique for amniotic membrane investigation: A preliminary study.

OBJECTIVE: The objective of this study was to evaluate and compare the two scanning electron microscope (SEM) preparation protocols and determine the better SEM preparation technique to study stem cells on human amniotic membrane (hAM) scaffold. MATERIALS AND METHODS: Formaldehyde-based protocol and glutaraldehyde-based protocol were compared to evaluate the quality of SEM images for stem cells cultured on hAM scaffold. RESULTS: The results suggested that formaldehyde-based protocol is better than glutaraldehyde-based protocol in terms of showing clearer topography of the membrane as well as the boarders of the cells. To provide intact surface of the SEM sample and avoid possible ruptures of the hAM or the thin cell layer, it is recommended to perform the dehydration step using graded alcohol concentrations of 20%, 30%, 40%, 50%, 60%, 70%, 80%, and 90%, one time for each and twice in 100% for 10 min each. Gold sputter-coating step is not recommended as it does not improve the image quality. CONCLUSIONS: To obtain clear SEM images, it is recommended to run a preliminary study to determine the better chemicals and conditions of sample preparation even when following preexisting protocols.

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.

Interaction of backfilling techniques and MTA plugs with additives: Fracture strength and adaptation analyses.

The aims were to evaluate the effects of different additives on the adaptation of mineral trioxide aggregate (MTA) plugs before and after different backfilling techniques and analyze the interference of filling procedures on the fracture resistance of simulated immature teeth. The apical parts of 60 teeth were filled with MTA mixed with distilled water (DW), propylene glycol (PG) or calcium chloride (CaCl2) and backfilled with cold lateral condensation (CLC) or warm vertical compaction (WVC). The specimens were subjected to adaptation analysis and fracture testing. CaCl2 addition resulted in poor marginal adaptation, while PG addition significantly decreased the fracture values (p<0.05). WVC technique negatively affected the marginal adaptation of MTA-CaCl2 plugs and decreased the fracture values of teeth with MTA-PG plugs (p<0.05). Mixing MTA with DW can be recommended as apical plug when the remaining root canal space is going to be filled with either CLC or WVC techniques.

Sealing ability and adaptation of root-end filling materials in cavities prepared with different techniques.

The aim of this study was to evaluate the sealing ability and marginal adaptation of calcium silicate-based cements (CSCs) in root-end cavities prepared by ultrasonic and laser tips. A total of 72 extracted human maxillary incisor teeth were randomly divided as 60 teeth in experimental groups and 6 teeth each for positive and negative control groups. Specimens in experimental groups were obturated, their root-end resections were performed and randomly divided into six groups (n = 10) as follows: G1: Ultrasonic retrotip + MTA, G2: Ultrasonic retrotip + Calcium Enriched Mixture (CEM), G3: Ultrasonic retrotip + Biodentine, G4: Er:YAG laser tip + MTA, G5: Er:YAG laser tip + CEM, G6: Er:YAG laser tip + Biodentine. The sealing ability was measured by fluid transport method. Six specimens from each experimental group were randomly selected to analyze marginal adaptation and prepared for scanning electron microscopy (SEM) analysis. Micrographs were scored and also analyzed using Image J software. Data were analyzed with; two-way ANOVA, Bonferroni, Kruskall-Wallis, Mann-Whitney-U, Siegel & Castellan, and Spearman correlation coefficient tests. No significant difference was found between materials regarding the sealing ability and marginal adaptation (p > 0.05). Significantly greater fluid movement and poor marginal adaptation were seen for materials placed in cavities prepared by laser tips (p < 0.05). Positive correlation was found between the results of scoring and Image J analysis of SEM images (r = 0.596, p < 0.001). Fluid transport method and SEM analysis gave similar results suggesting the use of ultrasonic-retrotips for preparing root-end cavities which are going to be filled with one of these CSCs.

In Vitro Cytotoxicity of Calcium Silicate-Based Endodontic Cement as Root-End Filling Materials.

The aim of this study was to evaluate the cytotoxicity of three types of calcium silicate-based endodontic cement after different incubation periods with human periodontal ligament fibroblasts. Human periodontal ligament fibroblasts were cultured from extracted third molars and seeded in 96-well plates. MTA, calcium enriched mixture (CEM) cement, and Biodentine were prepared and added to culture insert plates which were immediately placed into 96-well plates containing cultured cells. After incubation periods of 24, 48, and 72 hours, cell viability was determined with WST-1 assay. Data were analysed statistically by ANOVA with repeated measures and Bonferroni tests. There was no significant difference in cell viability amongst the test materials after each incubation period (P > 0.05). MTA and CEM presented more than 90% cell viability after 24 and 48 hours of incubation and showed statistically significant decrease in cell viability after 72 hours of incubation (P < 0.05). Biodentine showed significantly less cell viability (73%) after 24 hours of incubation, whereas more than 90% cell viability was seen after 48 and 72 hours of incubation (P < 0.05). Despite the significant changes in cell viability over time, materials presented similar cytotoxicity profile. Biodentine and CEM can be considered as alternative materials for root-end surgery procedures.

Efficacy of Combined Use of Different Nickel-Titanium Files on Removing Root Canal Filling Materials.

INTRODUCTION: The aim of this study was to estimate the remaining amount of residual filling materials in root canals after retreatment using ProTaper Universal Retreatment (PTUR) files (Dentsply Maillefer, Ballaigues, Switzerland) alone or with the additional use of the Self-Adjusting File (SAF; ReDent-Nova, Ra'anana, Israel), Reciproc (VDW, Munich, Germany), or Hedström-files (H-file; VDW, Antaeos, Munich, Germany) with volumetric estimation using the stereologic method via cone-beam computed tomographic images. METHODS: Forty-eight mandibular premolars with single canals were used. The canals were instrumented with ProTaper rotary instruments up to F4 and filled with gutta-percha and AH26 sealer (Dentsply De Trey, Johnson City, TN). All the samples were placed into the silicone models. Samples were scanned with cone-beam computed tomographic imaging and assigned into 4 groups (n = 12) according to retreatment files: the PTUR system group, the PTUR system plus SAF group, the PTUR system plus Reciproc group, and the PTUR system plus H-file group. The specimens were rescanned after retreatment procedures, and the volume estimations of the remaining filling materials were performed using the stereologic method. Data were analyzed using Kruskal-Wallis and Dunn tests. RESULTS: There was no significant difference among the groups regarding mean percentage volumes of the filling materials before retreatment procedures (P > .05). None of the retreatment procedures provided complete removal of the filling materials. The additional use of the SAF did not significantly improve the removal of filling materials when compared with the PTUR system alone (P > .05). However, the additional use of Reciproc or hand H-files significantly improved the removal of filling materials when compared with the PTUR system alone (P < .05). CONCLUSIONS: The additional use of files with different motion kinetics improved the removal of root canal fillings; however, none of the systems completely removed the root canal filling material from the root canals.

Effectiveness of behavioral modification techniques with visual distraction using intrasulcular local anesthesia in hearing disabled children during pulp therapy.

OBJECTIVE: Assessing the effectiveness of behavioral modification techniques in combination with visual distraction with/without video eyewear using computerized delivery system-intrasulcular (CDS-IS) during the application of local anesthetic in hearing-impaired pediatric patients undergoing pulp therapy of primary molars. MATERIALS AND METHODS: This randomized, crossover clinical study includes 15 children (7 boys and 8 girls), mean age was 6.1 years. Children were randomly distributed into two groups (Group A, n = 7; Group B, n = 8). The study involved three sessions, 1-week apart. During Session I, employing Tell-Show-Do technique, prophylactic dental cleaning was done while participants were watching a movie with sign-language interpretation with/without visual eyewear. At the end of Session I, score on Smiley Faces Program was used for anxiety assessment. During Session II and III, respectively, both groups underwent pulp treatment of equivalent teeth in the opposite sides of the mouth with/without video eyewear vice versa. After the procedure, children were instructed to rate their pain during treatment on the Wong-Bakers' (WBs') Faces Pain Scale. Changes in pulse oximeter and heart rate were recorded every 5 min. Paired sample t-test and independent sample t-test were used to assess the significance of changes during each visit. RESULTS: There was a significant (P > 0.04) change in the heart rate observed for Group A underwent pulp treatment while watching video using video eyewear. Self-reported mean pain score also increases during treatment sessions' with video eyewear, for both groups. CONCLUSION: Routine psychological (Tell-Show-Do) intervention along with visual distraction with full visibility of the surrounding and use of CDS-IS system for anesthetic delivery is recommended as an effective behavior management technique for children with hearing impairment undergoing invasive dental treatment.

Evaluation of the effects of two novel irrigants on intraradicular dentine erosion, debris and smear layer removal.

OBJECTIVES: To evaluate the effects of copolymer of acrylic acid and maleic acid (Poly[AA-co-MA]) and calcium hypochlorite (Ca(OCl)2) on root canal dentin using scanning electron microscope (SEM). MATERIALS AND METHODS: Twenty-four single-rooted teeth were instrumented and the apical and coronal thirds of each root were removed, leaving the 5 mm middle thirds, which were then separated into two pieces longitudinally. The specimens were randomly divided into six groups and subjected to each irrigant for 5 min as follows: G1, Ca(OCl)2; G2, Poly(AA-co-MA); G3, Ca(OCl)2 + Poly(AA-co-MA); G4, sodium hypochlorite (NaOCl); G5, ethylenediaminetetraacetic acid (EDTA); G6, NaOCl+EDTA. The specimens were prepared for SEM evaluation. Smear layer, debris and erosion scores were recorded by two blinded examiners. One image from G3 was analyzed with energy dispersive spectroscopy (EDS) on suspicion of precipitate formation. Data were analyzed using the Kruskal-Wallis and Dunn tests. RESULTS: G1 and G4 showed the presence of debris and smear layer and they were statistically different from G2, G3, G5 and G6 where debris and smear layer were totally removed (p < 0.05). In G1 and G4, erosion evaluation could not be done because of debris and smear layer. G2, G3 and G5 showed no erosion, and there was no significant difference between them. G6 showed severe erosion and was statistically different from G2, G3 and G5 (p < 0.05). EDS microanalysis showed the presence of Na, P, and Ca elements on the surface. CONCLUSIONS: Poly(AA-co-MA) is effective in removing the smear layer and debris without causing erosion either alone or with Ca(OCl)2.

Effectiveness of audiovisual distraction eyewear and computerized delivery of anesthesia during pulp therapy of primary molars in phobic child patients.

OBJECTIVES: The aim of this study is to assess the effectiveness of audiovisual distraction technique with video eyewear and computerized delivery system-intrasulcular (CDS-IS) during the application of local anesthetic in phobic pediatric patients undergoing pulp therapy of primary molars. MATERIALS AND METHODS: This randomized, crossover clinical study includes 60 children, aged between 4 and 7-year-old (31 boys and 29 girls). Children were randomly distributed equally into two groups as A and B. This study involved two treatment sessions of pulp therapy, 1-week apart. During treatment session I, group A had an audiovisual distraction with video eyewear, whereas group B had audiovisual distraction using projector display only without video eyewear. During treatment session II, group A had undergone pulp therapy without video eyewear distraction, whereas group B had the pulp treatment using video eyewear distraction. Each session involved the pulp therapy of equivalent teeth in the opposite sides of the mouth. At each visit scores on the Modified Child Dental Anxiety Scale (MCDAS) (f) were used to evaluate the level of anxiety before treatment. After the procedure, children were instructed to rate their pain during treatment on the Wong Bakers' faces pain scale. Changes in pulse oximeter and heart rate were recorded in every 10 min. RESULTS: From preoperative treatment session I (with video eyewear) to preoperative treatment session II (without video eyewear) for the MCDAS (f), a significant (P > 0.03) change in the mean anxiety score was observed for group A. Self-reported mean pain score decreases dramatically after treatment sessions' with video eyewear for both groups. CONCLUSION: The use of audiovisual distraction with video eyewear and the use of CDS-IS system for anesthetic delivery was demonstrated to be effective in improving children's cooperation, than routine psychological interventions and is, therefore, highly recommended as an effective behavior management technique for long invasive procedures of pulp therapy in young children.