Effect of Smear Layer on the Apical Seal of Endodontically Treated Teeth: An ex vivo Study

ABSTRACT Aim The purpose of this study was to evaluate the effect of smear layer on apical seal of endodontically treated teeth. Materials and methods Sixty freshly extracted human maxillary central incisor teeth were selected and were randomly divided into two experimental groups. Group A of 25 teeth and group B of 25 teeth and a control group of 10 teeth. Cleaning and shaping of the root canals were performed using endodontic K-files up to no. 50 size file in step-back technique. During the process, in root canals of group A, 17% EDTA (ethylenediaminetetraacetic acid) followed by 3% NaOCl (sodium hypochlorite) was used as root canal irrigant. In group B, MTAD (mixture tetracycline citric acid and detergent) was used as a root canal irrigant. In control group, saline was used as root canal irrigant. The root surfaces were then coated with nail polish of both experimental groups and control group. The samples were then immersed in India ink dye for 1 week at 37°C. Results The statistical analysis of the results showed that the apical leakage was significantly more in teeth, where smear layer was not removed. Conclusion The removal of smear layer improves the longterm apical seal and success of endodontically treated teeth. Clinical significance The development and maintenance of apical seal is desirable and considered to be a major prerequisite to improve the outcome of root canal treatment. How to cite this article Nischith KG, Srikumar GPV, Razvi S, Chandra RV. Effect of Smear Layer on the Apical Seal of Endodontically Treated Teeth: An ex vivo Study. J Contemp Dent Pract 2012;13(1):23-26.

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The impact of different irrigants on the quality of root canal walls

Stomatoloski glasnik Srbije ◽

10.2298/sgs0703160s ◽

2007 ◽

Vol 54 (3) ◽

pp. 160-169

Author(s):

Goran Stojilkovic ◽

Jovanka Gasic ◽

Jelena Dakovic

Keyword(s):

Root Canal ◽

Smear Layer ◽

Control Group ◽

Complete Elimination ◽

Canal Irrigation ◽

Root Canals ◽

Root Canal Irrigation ◽

Combined Use ◽

Group A ◽

Group B

Introduction: Root canal irrigation plays an important part in the endodontic therapy. Inadequate irrigation or instrumentation without irrigation increase the accumulation of debris on the cutting surfaces of instruments as well as debris and smear layer on root canal walls. Aim: The aim of this study was to evaluate smear layer removal after irrigation with saline, 5% NaOCl, 15% EDTA and the combination of 15% EDTA and 5% NaOCl. Materials and Methods: The study was conducted at the Clinic for Dentistry and Institute for biomedical research of the School of Medicine in Nis. Twenty five premolars, extracted from orthodontic reasons, were allocated to 5 groups (A-E) of 5 teeth. Root canals of all teeth were instrumented using hand K files. Samples from Group A were instrumented without irrigation (control group). In Group B, the irrigation was done using saline, in Group C 5% NaOCl, in Group D 15% EDTA and in Group E the combination of 15% EDTA and 5% NaOCl. After the treatment, all samples were prepared for scanning electron microscopy (SEM). Central parts of root canals were examined and photomicrographs were taken at different magnification. The amount of debris and smear layer was quantified and the data were statistically analyzed. Results: All four treatment modalities (B, C, D, E) induced changes in the appearance of dentinal walls and the amount of debris and the smear layer compared to the control group (A). The difference between the control group and Group B was statistically significant (p<0.01) and highly significant between the control group and Groups C, D and E (p<0.0001). The combined use of 15% EDTA and 5% NaOCl for irrigation and 1 min final rinse resulted in a complete elimination of the smear layer; the use of saline, 5% NaOCl or 15% EDTA alone failed to remove the debris and smear layer completely. Conclusion: The use of singular solutions for root canal irrigation significantly reduces the amount of debris and the smear layer whereas the combined use of NaOCl and EDTA results in the complete elimination of the smear layer from root canal walls.

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Efficacy of different instruments for the mechanical removal of the smear layer in immediate post preparations: a comparative study

Acta Odontológica Latinoamericana ◽

10.54589/aol.34/2/166 ◽

2021 ◽

Vol 34 (2) ◽

pp. 166-172

Author(s):

Marcela Roitman ◽

Laura Pinasco ◽

Romina Loiacono ◽

Valeria Panetta ◽

Carolina Anaise ◽

...

Keyword(s):

Root Canal ◽

Ex Vivo ◽

Close Contact ◽

Smear Layer ◽

Control Group ◽

Endodontically Treated Teeth ◽

Single Root ◽

Mechanical Removal ◽

Significant Difference ◽

Post Space

Adhesively cemented fiber-reinforced composite posts are commonly used to reconstruct endodontically treated teeth. Adhesion to intraradicular dentin is complex, and close contact between the resin cements and the dentin is essential. The removal of the smear layer following post space preparation (secondary smear layer) can improve this integration. Different mechanical systems have been used to activate the irrigant inside the root canal. The purpose of this study was to compare, ex-vivo, the removal of the smear layer from the walls of the immediate post space preparation by the action of three mechanized instruments. Forty premolar specimens with a single root canal were selected, endodontically treated, and shaped for glass fiber post cementation with Peeso reamer #1 (Dentsply Sirona, Switzerland) and Macrolock finishing drill #3 (RTD, France). The specimens were randomly divided into 4 groups (n=10): Group C (control); Group PUI (passive ultrasonic irrigation); Group CEP (Rotoprox brush, Hager Werken, Germany) and Group XP (XP-endo Finisher, FKG Dentaire, Switzerland). Post space surfaces were cleaned with 3mL of distilled water; each specimen root split longitudinally to expose the root canals, and prepared for examination in a scanning electron microscope at magnification 350X. The results were analyzed using the Kruskal-Wallis and Friedman tests (p>0.05). RESULTS: Statistically significant differences (p <0.05) were found between Groups C and XP in all three root regions, but not between Groups C, CEP and PIU. Of these, Group CEP showed a better trend in the results of the coronary and middle thirds, without significant difference with Group XP. Although it was difficult to achieve a clean dentin surface after preparation for the fiberglass post, the XP-endo Finisher was the most efficient in removing secondary smear layer, followed by the Rotoprox conical brush.

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Influence of Taper of Root Canal Shape on the Intracanal Bacterial Reduction

The Open Dentistry Journal ◽

10.2174/1874210601610010568 ◽

2016 ◽

Vol 10 (1) ◽

pp. 568-574 ◽

Cited By ~ 5

Author(s):

Mary Th. Paraskevopoulou ◽

Marouan G. Khabbaz

Keyword(s):

Root Canal ◽

Bacterial Count ◽

Positive Control ◽

Multiple Hypothesis Testing ◽

Control Group ◽

Bacterial Reduction ◽

Root Canals ◽

Significant Difference ◽

Group A ◽

Group B

Objectives: Taper is a factor that determines final root canal dimensions and consequently, the space available for the cleaning action of irrigants. Therefore, the aim of this study was to investigate the influence of taper on intracanal bacterial reduction. Methods: Sterilized root canals of 25 mandibular incisors were inoculated with E. faecalis and then divided into two experimental groups and one control group (A= saline, B= NaOCl + EDTA and C= control, not prepared). Groups A and B were prepared to an apical size of #30/0.04, a culture was obtained and then prepared to #30/0.08 and cultured again. Final irrigation sequence was 30 ml of saline for group A and 10 ml of 17% EDTA followed by 10 ml of 2.5% NaOCl and 10 ml of saline for group B. The CFU ml-1 of the pre- and two post-operative samplings were recorded. Values were compared by performing ANOVA and FDR for multiple hypothesis testing. Results: No statistically significant difference between initial CFU ml-1 readings was recorded, whereas significant differences between group A and B at both 4% and 8% tapers were noted. Furthermore, a linear-dependent reduction of CFU ml-1 was recorded in each group from non-instrumented root canals to #30/0.04 and subsequently to #30/0.08. The positive control group shows the expected reduction of bacterial count. Conclusion: Chemomechanical instrumentation was more efficient at reducing E. faecalis when the taper of root canals increased from 4% to 8% and NaOCl plus EDTA led to a greater intracanal bacterial reduction than saline, regardless of the taper achieved.

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In vivo analysis of post space sealing with different adhesive materials

Journal of Applied Oral Science ◽

10.1590/s1678-77572003000300003 ◽

2003 ◽

Vol 11 (3) ◽

pp. 168-174 ◽

Cited By ~ 2

Author(s):

Carlos Alexandre Souza Bier ◽

José Antônio Poli de Figueiredo ◽

Álvaro Della Bona ◽

Patrícia Maria Poli Kopper ◽

José Roberto Vanni ◽

...

Keyword(s):

Root Canal ◽

Adhesive System ◽

Control Group ◽

Filling Material ◽

Root Canals ◽

India Ink ◽

Group A ◽

Provisional Restoration ◽

Post Space

This in vivo study analyzed the sealing ability of two adhesives in post spaces, cyanoacrylate (Super Bonder® - Henkel Loctite Adesivos Ltda., Itapevi, SP, Brazil) and ScotchbondTM Multi-Purpose (3M Dental Products, St. Paul, MN, USA), testing the hypothesis that their use would result in a decreased leakage through the remaining filling material. Forty extracted premolars (80 root canals) of dogs were used. The root canals were cleaned, shaped and filled by the lateral condensation technique using Sealer 26TM. The post space was created removing two thirds of the filling material within the root canal. The canals were randomly divided in three groups, which were treated as follows: Group A received the ScotchbondTM Multi-Purpose adhesive system; for Group B the cyanoacrylate adhesive, Super BonderTM, was employed; and no adhesive was applied into the post space for Group C (control group). A glass ionomer provisional restoration was placed allowing the sealer to set for 72 hours. Then the restoration was removed and the root canal was exposed to the oral environment for 45 days. The dogs were then killed and their jaws were removed. The post spaces were filled with India ink and the teeth were restored for 96 hours. Afterwards, the teeth were extracted and the roots were sectioned at the furcation for allocation to their specific groups. The teeth were turned transparent and the quantitative analysis of leakage was performed using light microscopy. The results showed no significant differences between groups, rejecting the initial hypothesis. Leakage occurred in a great extent in all specimens. Therefore, sealing post spaces with the adhesives used in this study was not an effective method to prevent microleakage.

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Microbial Leakage of Cavit, IRM, and Temp Bond in Post-prepared Root Canals Using Two Methods of Gutta-percha Removal: An In Vitro Study

The Journal of Contemporary Dental Practice ◽

10.5005/jcdp-6-3-53 ◽

2005 ◽

Vol 6 (3) ◽

pp. 53-61 ◽

Cited By ~ 9

Author(s):

Hanan Balto ◽

Saad Al-Nazhan ◽

Khulood Al-Mansour ◽

Moneera Al-Otaibi ◽

Yunus Siddiqu

Keyword(s):

Root Canal ◽

Bacterial Suspension ◽

Control Group ◽

Endodontically Treated Teeth ◽

Root Canals ◽

Gutta Percha ◽

Working Length ◽

Significant Difference ◽

Post Space

Abstract The aim of this study was to evaluate the integrity of the coronal seal of Temp-Bond and compare it to Cavit and IRM after post space preparation using S. faecalis as a microbial tracer. In addition, the affect of two methods of gutta percha removal on the apical seal of root canal fillings was also evaluated. Forty extracted human single rooted teeth were prepared chemomechanically and obturated with gutta percha and AH26 sealer cement using the lateral cold condensation technique to a standardized working length of 15 mm. About 10 mm of the coronal gutta-percha was removed with either Peeso-reamer or a hot plugger. The roots were divided into three experimental groups of 10 roots and a control group. Each experimental group was subdivided equally into two groups of 15 each according to the method of post space preparation. Cavit, IRM, and Temp-Bond were used to seal the access opening. Each root was fixed in a cuvette containing Tryptic Soya Broth which, covered 2 mm of the root apex. Bacterial suspension was introduced through pipette. Fresh bacterial suspension was added every week, and the system was monitored daily for the growth of microorganisms for a period of one month. The results showed there was no significant difference in terms of coronal leakage between the three coronal materials used (P=0.478), but the methods of gutta-percha removal did have an impact on the apical leakage (P=0.047). The mean value showed the Peeso-reamer provided less leakage compared to using a hot plugger during the 30-day experimental time period. It was concluded the temporary type of coronal seal of endodontically treated teeth will not prevent coronal leakage if left for a long period of time. In addition, permanent cementation of the post with the coronal restoration should be carried out as soon as possible to prevent recontamination of the root canal. Citation Balto H, Al-Nazhan S, Al-Mansour K, Al-Otaibi M, Siddiqu Y. Microbial Leakage of Cavit, IRM, and Temp Bond in Post-prepared Root Canals Using Two Methods of Gutta-percha Removal: An In Vitro Study. J Contemp Dent Pract 2005 August;(6)3:053-061.

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Endodontic Irrigants and Their Activation Efficacy on Cleansing Post-Space Root Canal Walls

Prosthesis ◽

10.3390/prosthesis3040036 ◽

2021 ◽

Vol 3 (4) ◽

pp. 406-414

Author(s):

Manuela Marchese ◽

Pontoriero I. K. Denise ◽

Edoardo Ferrari Cagidiaco ◽

Alfredo Iandolo ◽

Simone Grandini ◽

...

Keyword(s):

Root Canal ◽

Continuous Wave ◽

Smear Layer ◽

The Other ◽

X Rays ◽

Ultrasonic Activation ◽

Gutta Percha ◽

Bonding System ◽

Group A ◽

Group B

The aim of this study was to evaluate the efficacy of activated irrigants (EDTA e NaOCL) during the cleansing of root walls, of the smear layer, of the debris, and gutta-percha after the preparation of the restorative space. Twenty single and multi-rooted (n = 20) have been collected. All samples were prepared by the same operator, using Nickel-titanium rotating instruments (Mtwo) through the Simultaneous Shaping Technique. The continuous-wave of condensation technique of obturation was used. To all specimens, the restorative space has been made, leaving 5 mm of apical gutta-percha, and postoperative periapical X-rays were performed. The samples were randomly divided into two groups: Group (A): cleansing of the root walls with ultrasonic activation of the irrigants (NEWTRON P5 XS; Satelec Acteon); Group (B): radicular walls wash without ultrasonic activation of endodontic irrigants (NaOCl 5.25% and EDTA 17%). Both dental sample groups were cut longitudinally with a low-speed saw (Isomet); the samples were observed by using a scanning electron microscope (Jeol, Jsm-6060LV) in order to evaluate: (1) the amount of debris/smear layer; (2) the mount of obstruction of dentinal tubules found in the two groups; and (3) evaluation of the presence of gutta-percha. Then, the other five samples each group (with and without ultrasonic activation) were prepared following the same protocol. Then, a universal bonding system (G-Praemio Bond, GC) and a layer of a flowable resin composite (Gaenial Flow, GC) were light-cured and used on top of the prepared root canal walls. The samples were cut in two pieces along the long axis of the root. Then, half sample teeth were kept in an acidic solution (37% HCl) for 48 h in order to completely dissolve dental structures and to have a direct view of resin tags formation under SEM. The other half was prepared to observe the adhesive interface under SEM. The amount of debris was not satisfactory in 9 out of 10 cases in Group B, while in Group A, which has been treated with ultrasounds, the result was either good or great in most of the samples. For the sample group treated with ultrasound, the tubules were evaluated as perfectly clean in 9 out of 10 cases, instead, the results are unsatisfactory for 9 out of 10 cases of group B not treated with ultrasound. Differences between Group A and B were statistically significant. With respect to the presence of debris and tubules obstruction treatment with ultrasonic activation, it offers with no doubt better results. When ultrasonic activation is used in combination with endodontic irrigants, a clean dentin substrate is be obtained for the adhesion of restorative materials, but in order to confirm the findings of this study, further in vivo trials are needed.

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Effectiveness of a Canal Brush on Removing Smear Layer: A Scanning Electron Microscopic Study

Brazilian Dental Journal ◽

10.1590/0103-6440201302272 ◽

2013 ◽

Vol 24 (6) ◽

pp. 580-584 ◽

Cited By ~ 1

Author(s):

Eleni Protogerou ◽

Ioanna Arvaniti ◽

Ioannis Vlachos ◽

Marouan Georgios Khabbaz

Keyword(s):

Statistical Difference ◽

Optical Microscope ◽

Smear Layer ◽

Electron Microscopic ◽

Root Canals ◽

Scanning Electron Microscopic Study ◽

Scanning Electron Microscopic ◽

Group A ◽

Group B ◽

Scanning Electron

This study evaluated the effectiveness of a highly flexible endodontic brush made of polypropylene canal brush (CanalBrush; Coltène) on smear layer removal from the canal walls when used according to the manufacturer's recommendations. Forty-four single-rooted mandibular incisors were prepared to apical size 30/0.06 and randomly divided into three groups A, B and C, where the final irrigation regimen was 10 mL 17% EDTA and 10 mL 2.5% NaOCl for group A, 10 mL EDTA, 5 mL NaOCl, CanalBrush for 20 s at 450 rpm and 5 mL NaOCl for group B, 10 mL NaOCl, CanalBrush and 10 mL NaOCl for group C. One medium-sized CanalBrush was used for each root canal and all brushes were examined under the optical microscope after application to evaluate bristle deformation. Afterwards, roots were split longitudinally and the presence of smear layer was evaluated under a scanning electron microscope. Used brushes invariably exhibited bristle deformation. Group C exhibited the highest means of smear layer in all thirds. Comparing the apical thirds in all groups, there was no statistical difference between groups A and B (3.64±0.48 and 3.68±0.62 respectively), while group C exhibited significantly higher scores (3.9±0.28) than the other two groups. In conclusion, the CanalBrush proved unable to remove smear layer from the instrumented root canals, when used according to the manufacturers' instructions.

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The Effect of Different Cleaning Protocols on Post Space: A SEM Study

International Journal of Dentistry ◽

10.1155/2016/1907124 ◽

2016 ◽

Vol 2016 ◽

pp. 1-7 ◽

Cited By ~ 10

Author(s):

Giuseppe Lo Giudice ◽

Angelo Lizio ◽

Roberto Lo Giudice ◽

Antonio Centofanti ◽

Giuseppina Rizzo ◽

...

Keyword(s):

Orthophosphoric Acid ◽

Acid Group ◽

Smear Layer ◽

Control Group ◽

Apical Direction ◽

Sem Study ◽

Group A ◽

Group B ◽

Group D ◽

Post Space

Aim. Purpose of the present paper is to analyze the efficiency of different post-space irrigation protocols.Methods. 28 single rooted teeth were endodontically treated. After post-space preparation every sample was assigned to one of three experimental groups and to one control group. In each group different irrigation protocols were performed as follows: EDTA (Group A), 37% orthophosphoric acid (Group B), and EDTA + 37% orthophosphoric acid with ultrasounds activation (Group C). In the control group (Group D) the irrigate association was not activated by ultrasounds. Three zones (coronal, middle, and apical) of each sample were analyzed by using Scan Electron Microscopy (SEM) without any metallization procedures. The presence of smear layer on the canal surface was qualitatively evaluated by applying Serafino’s score with values included between 0 and 2.Results. The results of the research showed how Group C recorded the better results (0.81±0.72). Group A and Group B showed lower mean scores (1.06±0.69and1.08±0.77); Group D showed the lowest mean score of1.30±0.69. The SEM observation analysis demonstrated how the smear layer presence decreased in the crown-apical direction.Conclusions. The different post-space treatments statistically determine significant differences on the dentinal surfaces cleansing. The absence of ultrasonic activation lowers the cleansing efficacy of endocanalar irrigants, showing sensible differences among each post-space zone.

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Evaluation of apical deviation in root canals instrumented with K3 and ProTaper systems

Journal of Applied Oral Science ◽

10.1590/s1678-77572006000600013 ◽

2006 ◽

Vol 14 (6) ◽

pp. 460-464 ◽

Cited By ~ 3

Author(s):

Mariana Diniz Bisi dos Santos ◽

Marília Fagury Marceliano ◽

Patrícia Rodrigues de Almeida Silva e Souza

Keyword(s):

Root Canal ◽

Three Dimensional ◽

System Evaluation ◽

Parametric Test ◽

Root Canals ◽

Before And After ◽

Group A ◽

Group B ◽

Curved Root Canals

OBJECTIVES: this study evaluated the apical deviation of curved root canals instrumented with K3 and ProTaper systems. MATERIAL AND METHODS: twenty root canals of human maxillary and mandibular first molars were employed, which were divided into 2 groups: group A (10 teeth) was instrumented with the K3 system, and group B (10 teeth) with the ProTaper system. Evaluation of deviation was performed by double radiographic exposure. Radiographs were achieved before and after instrumentation, with 0.3-second, thus allowing superimposition of images. Three-dimensional computerized tomograph was performed in 3 specimens in each group, as an additional means to evaluate the apical deviation. RESULTS: were evaluated by the parametric test Student-Newman-Keuls at 5%, which did not reveal significance between groups concerning the apical deviation. The results of computerized tomograph images demonstrated that the larger deviation of the root canal occurred at the distolingual area for both systems. CONCLUSIONS: both techniques produced a mild apical deviation. Computerized microtomography was shown to be accurate for experimental endodontics studies.

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