Showing 3 results for Smear Layer
N Roghanizad, M Vatanpour, L Moradi Eslami , H Bahrami,
Volume 2, Issue 4 (10-2017)
Abstract
Background and Aim: Debris and the smear layer that remain after root canal preparations may result in failure of root canal therapies. The aim of this study was to compare the smear layer formation and the amount of residual debris following the use of WaveOne and ProTaper rotary files in mesiobuccal root canals of upper first molars by scanning electron microscopy (SEM).
Materials and Methods: In this experimental study, 34 mesiobuccal root canals of human maxillary first molars with 20°-40° curvatures (according to Schneider technique) were randomly distributed in two experimental groups (15 each) and two control groups. The canals in test groups were instrumented according to the manufacturers’ instructions. Five ml of 5.25% sodium hypochlorite (NaOCl) and 5 ml of normal saline were used as irrigants. The roots were split longitudinally, and apical, middle, and coronal radicular sections were randomly scanned by an SEM at ×1000 magnification. Two endodontists scored the data according to Schäfer and Schlingemann scoring system. Data of the amount of debris and smear layer were separately analyzed by Kruskal-Wallis test.
Results: Although there was a slight difference in mean scores between the two groups (3.28 for WaveOne and 3.6 for ProTaper), no significant differences in debris amount were noted. The overall mean smear layer formation was not significantly different between the two groups (4.11 for WaveOne and 3.95 for ProTaper).
Conclusion: There was no significant difference in remaining debris and smear layer in coronal, middle, and apical parts of root canals. However, ProTaper system appeared to produce less debris during preparation.
H Shahraki Ebrahimi, A Motameni Tabatabaie, S Bakhshi Moqaddam Firouz Abad, Y Fereydonnia,
Volume 6, Issue 4 (9-2021)
Abstract
Background and Objectives: Complete debridement of the root canal system is imperative for successful endodontic treatment. This study compared apical extrusion of debris following the use of different brands of ProTaper system.
Materials and Methods: This in vitro experimental study was conducted on 80 extracted mandibular molars. After access cavity preparation, working length was determined by a #10 K-file. The teeth were mounted in an experimental setup as explained by Myers and Montgomery and were randomized into 4 groups (n=20) for root canal instrumentation with ProTaper Universal (PTU), Dia-PT file (DPT), PathMax Pro (PMP), and hand files. The root canals were irrigated with double distilled water after using 2 files. After preparation, the debris collecting tubes were separated from the setup. Debris adhering to root surface was also collected by rinsing the canals with 1 mL of double distilled water. The tubes were incubated at 70°C for 5 days. Dried debris was weighed and subtracted from the weight of empty tubes. Data were analyzed by ANOVA.
Results: The extruded debris in PTU group was significantly higher than that of DPT and PMP groups (P<0.05). The extruded debris in DPT group was significantly lower than that in PTU and hand file groups (P<0.05). The extruded debris in hand file group was significantly higher than DPT and PMP groups (P<0.05). The extruded debris in PMP group was significantly lower than PTU and hand file groups.
Conclusion: PTU caused maximum and PMP caused minimum extrusion of debris.
R Ghaseminejad, A Azizi, M Fazlyab, S Toursavadkouhi,
Volume 6, Issue 4 (9-2021)
Abstract
Background and Aim: Methylene blue and curcumin are effective photosensitizers for inactivation of bacteria. This study assessed the penetration depth of methylene blue and curcumin in presence/absence of smear layer into dentinal tubules.
Materials and Methods: Thirty-two human central and lateral incisors were included in this experimental study. The initially prepared specimens were randomly allocated to 4 experimental groups: Group 1: methylene blue with smear layer, group 2: methylene blue without smear layer, group 3: curcumin with smear layer, group 4: curcumin without smear layer. Root specimens were sectioned by a diamond disc at 4 and 8 mm from the apex to obtain apical, middle, and coronal sections. The mean penetration depth was measured at the buccal, mesial, distal and palatal areas on cross sections. ANOVA was used to assess the effect of photosensitizer type, smear layer, and root level on penetration depth. Pairwise comparisons were performed by the Student’s t-test.
Results: The maximum penetration depth was in the apical third in group 2 (0.98±0.25 mm) and the minimum penetration depth was in the coronal third in group 1 (0.21±0.15 mm); this difference was significant (P=0.001). Smear layer removal from the apical and middle thirds was correlated with higher photosensitizer penetration depth (P=0.000) but this difference was not significant in the coronal third (P=0.6). Curcumin had significantly greater penetration depth in presence of smear layer in all three parts compared with methylene blue (P<0.05).
Conclusion: Curcumin can penetrate more into dentinal tubules than methylene blue in presence of smear layer.
