The effect of working length and root canal preparation technique on crack development in the apical root canal wall

Abstract The effect of root canal preparation technique on microcrack initiation is a controversial issue. This systematic review aimed to assess the role of root canal preparation techniques with different kinematics (manual, rotary, reciprocating, adaptive, self-adjusting file) on microcrack initiation. In vitro and in situ studies comparing the influence of at least two different root canal preparation techniques on the initiation of dentin microcracks were searched in PubMed/MEDLINE and SCOPUS up to June 5, 2018 without language and period restriction. Two authors independently reviewed all identified titles and abstracts for eligibility. Tables were generated to summarize the included studies, and the included studies were assessed for bias. Fifty-four (n=54) articles met the eligibility criteria. The results were classified according to the method used for microcrack evaluation, and most studies that used micro-computed tomography showed no formation of new cracks after root canal preparation. In general, the instrumentation techniques induced microcrack formation when the methods were destructive, irrespective of kinematics. In relation to the apex region, when the preparation working length was set as the root canal length subtracted of 1 mm, the risk of microcrack initiation reduces. The majority of the included studies had low risk of bias for all assessed domains. Our results seem to indicate that the various root canal preparation techniques considered in this study will not cause damage to the dental structure when adequately employed and the proper methodology is applied.

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Preliminary Simulation of the Flow in the Root Canal Using New Irrigation Needle

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.772.621 ◽

2015 ◽

Vol 772 ◽

pp. 621-625 ◽

Cited By ~ 1

Author(s):

Dragoș Isvoranu ◽

Sterian Danaila

Keyword(s):

Shear Stress ◽

Root Canal ◽

Volume Fraction ◽

Great Efficiency ◽

Root Canal Preparation ◽

Two Phase ◽

Irrigation Flow ◽

Working Length ◽

Two Component ◽

Simulation Results

The main purpose of this paper is to explore the possibility of using a new irrigation device to achieve the goals of root canal preparation for endodontic procedures. A secondary goal is to introduce the never before used physical approach of two-phase, two-component irrigation flow in the root canal. Our simulation results show great efficiency of the irrigation procedure in terms of the irrigant volume fraction and wall shear stress at the wall of the root canal over entire working length.

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A Survey of Standard Protocols for Endodontic Treatment in North of KSA

ISRN Dentistry ◽

10.1155/2014/865780 ◽

2014 ◽

Vol 2014 ◽

pp. 1-4 ◽

Cited By ~ 4

Author(s):

Azhar Iqbal ◽

Iftikhar Akbar ◽

Beenish Qureshi ◽

Mohd G. Sghaireen ◽

Mahmoud K. AL-Omiri

Keyword(s):

Saudi Arabia ◽

Root Canal ◽

Computer Software ◽

Endodontic Treatment ◽

Preparation Technique ◽

Gutta Percha ◽

Working Length ◽

True Representation ◽

Length Determination ◽

General Dentists

The objective of this study was to collect information regarding methods, materials, and attitudes employed during the endodontic treatment by dentists in north of Saudi Arabia. A questionnaire was designed and distributed among 300 dentists in north of Saudi Arabia to collect the data about the standard protocols of endodontic treatment. The collected data was analyzed by using the SPSS 10 computer software. Out of a total of 300 surveyed dentists, the 66% response rate showed that this study was true representation of the endodontic treatment performed by the dentists in north of Saudi Arabia. 152 (76%) were general dentists and 48 (24%) were endodontists. 18 (9%) were using rubber dam as the method of isolation during endodontic treatment. 173 (86.5%) were using only measurement radiographs for working length determination and 27 (13.5%) were using both electronic apex locator and measurement radiographs. 95 (47.5%) of the respondents were using standardized technique and 25 (12.5%) were using step-down as a root canal preparation technique. 127 (63.5%) of the respondents were using lateral condensation technique, with gutta percha points for root canal obturation.

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CROWN DOWN PREPARATION TECHNIQUE WITH LARGE TAPER ENDODONTIC HAND INSTRUMENT

Interdental Jurnal Kedokteran Gigi (IJKG) ◽

10.46862/interdental.v17i1.2075 ◽

2021 ◽

Vol 17 (1) ◽

pp. 41-48

Author(s):

Asri Riany Putri ◽

Keyword(s):

Stainless Steel ◽

Root Canal ◽

Working Time ◽

Root Canal Treatment ◽

Preparation Technique ◽

Root Canal Preparation ◽

Periapical Lesions ◽

Root Canals ◽

Root Canal System ◽

Conventional Stainless Steel

Introduction: Root canal preparation is an important step in root canal treatment. The use of stainless steel K-Files is time-consuming and causes fatigue to patients and operators. The large taper endodontic hand instrument can be used as an option for another preparation instrument. The purpose of this article is to determine the advantages of using large taper endodontic hand instruments as a preparation instrument compared to conventional stainless steel K-Files. Case: The 24-year-old male patient presented with pain in his lower left tooth even though it was not used. Examination of teeth 35, percussion and press (+), palpation (-), CE (-), exploration of root canals with smooth broach (+). There was a radiolucent image in the distal crown that had reached the pulp chamber, radiolucency with a blurred border of 2 mm in diameter at the periapical area, and the dilation of the periodontal ligaments along with the roots. Tooth 35 diagnosis was partial pulp necrosis with periapical lesions. Case Management: Root canal treatment of teeth 35 using hand-used ProTaper with the crown down technique up to F4 WL = 21 mm. Obturation with single cone technique with Endomethasone as a sealer. Discussion: The large taper instrument is very flexible and easily enters narrow and bent root canals, thus it can shorten the working time, reduce the risk of fatigue for patients and operators, improves the cleaning of the root canal system, and consistent root canal formation. The crown down technique used can reduce the risk of preparation errors, prevent debris extrusion and improve obturation quality. Conclusion: Root canal preparation using a large taper endodontic hand instrument can shorten the working time and reduce the risk of fatigue for patients and operators compared to preparations using conventional stainless steel K-File.

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A Comparison of Cone Beam Computed Tomography and Periapical Digital Radiography for Evaluation of Root Canal Preparation

Applied Sciences ◽

10.3390/app11146599 ◽

2021 ◽

Vol 11 (14) ◽

pp. 6599

Author(s):

Khoa Van Pham

Keyword(s):

Computed Tomography ◽

Digital Radiography ◽

Cone Beam Computed Tomography ◽

Root Canal ◽

Cone Beam ◽

Root Canal Preparation ◽

Radiographic Images ◽

Digital Radiograph ◽

Working Length ◽

Before And After

The aim of the present study is to compare cone beam computed tomography and periapical digital radiography for the evaluation of root canal preparation. Nine extracted human molars were used in this study. Following access cavity preparation, mesio-buccal roots of maxillary and mesial roots of mandibular molars were prepared and the remaining roots were cut off. Three amalgam cavities were prepared on the coronal part of the teeth and were filled with amalgam to be used as landmarks. Specimens were scanned using cone-beam computed tomography and periapical digital radiograph images were obtained before and after root canal preparation. WaveOne Gold Primary was used for root canal preparation to full working length. Specimens were then scanned using CBCT and a periapical radiograph for the after-instrumentation images. The transportation and centering ratio were measured and calculated on the CBCT and periapical radiographic images. The Bland–Altman method was used for detecting the bias in the evaluation of agreement between the two methods’ measurements. There was agreement between the two methods’ measurements using CBCT scans and periapical digital radiographic images in the evaluation of transportation and centering ratio parameters. The two methods could be used interchangeably in measurements of transportation and calculating the centering ratio.

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Establishing Apical Patency: To be or not to be?

The Journal of Contemporary Dental Practice ◽

10.5005/jp-journals-10024-2040 ◽

2017 ◽

Vol 18 (4) ◽

pp. 326-329 ◽

Cited By ~ 1

Author(s):

Hamid Jafarzadeh ◽

Zahed Mohammadi ◽

Sousan Shalavi ◽

Jun-Ichiro Kinoshita

Keyword(s):

Root Canal ◽

Animal Studies ◽

Detrimental Effect ◽

Apical Part ◽

Endodontic Treatment ◽

Root Canal Preparation ◽

Apical Constriction ◽

Apical Portion ◽

Gutta Percha ◽

Working Length

ABSTRACT Introduction The apical portion of the root canal is very complex and challenging during endodontic treatment. Root canal preparation and obturation to the apical constriction may provide the best prognosis. Incomplete debridement, foramen transportation, and inadequate seal in the apical portion are considered to be responsible for treatment failure. The technique “apical patency” is considered as a way for maintaining the apical part the free of the debris by recapitulation, using a small K-file through the area of the apical foramen. This term was firstly proposed by Buchanan. In this technique, the smallest diameter file is set 1 mm longer than working length and recapitulated after each instrument to prevent packing of debris in the apical part. Apical patency has been found to be effective in achieving an apical seal with gutta-percha. Teeth prepared with a step back method and with maintained apical patency may show less leakage when obturated with cold lateral condensation technique. Data regarding the effect of apical patency on the healing of periapical tissue are very scarce, and it has been shown that the patency file has detrimental effect on the healing of periapical tissues in animal studies. However, using patency file in endodontic treatment is controversial and further studies are needed. The purpose of this article is to review the effect of using a patency file on the extrusion of root canal contents, the apical seal, postoperative pain, and healing of periapical tissues. Furthermore, the effect of establishing patency on reaching irrigation solutions to the apical portion of the canal and prognosis of root canal treatment are discussed. Clinical significance How to cite this article Mohammadi Z, Jafarzadeh H, Shalavi S, Kinoshita J-I. Establishing Apical Patency: To be or not to be? J Contemp Dent Pract 2017;18(4):326-329.

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A Novel Root Canal Preparation Technique Hybridizing Heat-treated Nickel-Titanium Rotary Instruments

World Journal of Dentistry ◽

10.5005/jp-journals-10015-1830 ◽

2021 ◽

Vol 12 (3) ◽

pp. 258-262

Author(s):

Shilpa Bhandi ◽

Gianluca Gambarini ◽

Marco Seracchiani ◽

Luca Testarelli ◽

Dario Di Nardo ◽

...

Keyword(s):

Root Canal ◽

Nickel Titanium ◽

Preparation Technique ◽

Root Canal Preparation ◽

Heat Treated ◽

Rotary Instruments

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Apical Extrusion of Debris during Root Canal Preparation with ProTaper Next, WaveOne Gold and Twisted Files

Materials ◽

10.3390/ma14216254 ◽

2021 ◽

Vol 14 (21) ◽

pp. 6254

Author(s):

Wojciech Eliasz ◽

Beata Czarnecka ◽

Anna Surdacka

Keyword(s):

Root Canal ◽

Root Canal Preparation ◽

Movement Kinematics ◽

Liquid Component ◽

Apical Extrusion ◽

Working Length ◽

Adaptive Motion ◽

Group 3 ◽

Group 2 ◽

Group 1

(1) Background: Apical extrusion of debris is an example of a complication that may arise during root canal treatment, and it has been proven to be an unavoidable occurrence during endodontic treatment by numerous authors. Even though it may not hinder the long-term outcome of treatment, it may lead directly to increased levels of postoperative pain and, therefore, lower levels of patient acceptance and satisfaction. The aim of the study was to assess the weight of apically extruded debris during root canal preparation with instruments that use different movement kinematics (rotary, reciprocating, and adaptive motion); (2) Methods: The study was performed using the Myers and Montgomery model. Sixty human premolar teeth were inserted into preweighed Eppendorf tubes and randomly classified into three groups. After manual glide-path preparation, teeth in each group were instrumented to working length set 1 mm short of the anatomical apex using the standard sequence provided by the manufacturers (for Group 1: ProTaper Next X1 & X2; for Group 2: WaveOne Gold Primary, for Group 3: Twisted Files SM1-SM3). Root canals were irrigated with 1 mL of 0.9% NaCl solution between each file insertion. The tubes with collected debris were stored in an incubator at 70 °C for 5 days in order to evaporate the liquid component. Measurement of the weight of extruded debris was performed by subtracting the preinstrumentation from the postinstrumentation weight of the tubes. The results were analyzed with Kruskal–Wallis ANOVA, with significance level set at 0.05; (3) Results: The weight of extruded debris was 0.337 mg (SD = 0.148) for Group 1, 0.305 mg (SD = 0.201) for Group 2, and 0.348 mg (SD = 0.135) for Group 3. (4) Conclusions: Engine-driven root canal preparation with the use of instruments ProTaper Next, WaveOne Gold and Twisted Files that use different movement kinematics (rotary, reciprocating, and adaptive motion) was associated with apical extrusion of debris to a similar extent.

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Effect of 17% EDTA on removal of canal wall smear layer and calcium hydroxide dressing: part II

RGO - Revista Gaúcha de Odontologia ◽

10.1590/1981-8637201400010000082382 ◽

2014 ◽

Vol 62 (1) ◽

pp. 53-58

Author(s):

Rosana de Souza PEREIRA ◽

Gisela de Souza PEREIRA ◽

Juliana Machado BARROSO ◽

Carlos Henrique Siqueira BARROS ◽

Márcia Gabriella Lino de Barros BORTOLOTTI ◽

...

Keyword(s):

Calcium Hydroxide ◽

Propylene Glycol ◽

Root Canal ◽

Smear Layer ◽

Canal Wall ◽

Group Iii ◽

Group I ◽

Working Length ◽

Almost All ◽

Scanning Electron

OBJECTIVE: the aim of this study was to evaluate, by scanning electron microscopy, the effectiveness of 17% EDTA on removal of canal wall smear layer and calcium hydroxide dressing in different thirds of root canal. METHODS: Ttwenty-four premolars were instrumented in the cervical and middle thirds using Gates-Glidden drills. At the working length, the canal was widened up to # 35 file, followed by scaling up to file # 50. After instrumentation, the teeth were divided into four groups according to the treatment received: GI - irrigation performed with 5 ml of NaOCl 2.5 % ; GII - irrigation with 5 ml of 17% EDTA for 2 and a half minutes , submitted to agitation with file # 15, followed by irrigation with 5 ml of 2.5% NaOCl ; GIII - irrigation with 5 ml of NaOCl 2.5% , drying , application of temporary dressing of Ca (OH )2 with propylene glycol and sealing. After 5 days , removing the sealing irrigation with 5 ml of 17% EDTA for 2 and a half minutes , submitted to agitation with file # 15, followed by a final flush with 5 ml of 2.5% NaOCl ; GIV - irrigation with 5 ml of 17% EDTA for 2 and a half minutes , submitted to agitation with file # 15 , followed by irrigation with 5 ml of 2.5% NaOCl , drying and after use of the medication in Ca (OH )2 with the sealing and propylene glycol which was removed after 5 days performing the irrigation with 5 ml of 17% EDTA for 2 and a half minutes , submitted to agitation with file # 15, followed by using 5 ml 2.5% NaOCl . Next, the teeth were prepared and taken to the scanning electron microscope . RESULTS: The images revealed: Group I - a marked presence of smear layer in all three thirds, Group II - removal of almost all of the smear layer in the cervical third and removal of large quantity in the middle third, whereas in the apical third a large quantity of smear layer still remained however, in comparison with the other groups, this was shown to be cleaner; Group III - in the three thirds, the presence of smear layer was observed, which was shown to be much less compacted than that observed in Group 1; Group IV- in all the thirds there was reduction of smear layer and Ca(OH)2-based medication, and presence of several unobstructed dentinal tubules could be observed, demonstrating the second best result observed. CONCLUSION: It could be concluded that the use of 17% EDTA favored removal of the smear layer and intracanal medication residues in all thirds of the root canal.

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The influence of working length on the reduction of biofilm and planktonic bacteria in oval canals with reciprocating instrumentation

Research Society and Development ◽

10.33448/rsd-v10i5.14765 ◽

2021 ◽

Vol 10 (5) ◽

pp. e9810514765

Author(s):

Arieth Cristina Sacomani ◽

Fernanda Tessaro Cintra ◽

Adriana de Jesus Soares ◽

Marcos Frozoni

Keyword(s):

Bacterial Growth ◽

Root Canal ◽

Negative Control ◽

Bacterial Biofilm ◽

Control Group ◽

Root Canal Preparation ◽

Root Canals ◽

Planktonic Bacteria ◽

Working Length ◽

Significant Difference

To evaluate the influence of reciprocating single-file instrumentation with different working lengths (WL) on the reduction of planktonic bacteria and bacterial biofilm in Enterococcus faecalis-contaminated oval root canals. Methodology: Fifty-five human single-rooted canines were used. Fifty were inoculated with E. faecalis for 21 days for biofilm formation. To confirm the formation of biofilm adhered to the root canal wall, 5 contaminated samples from positive control group were analyzed by SEM. Samples were assigned into 3 groups (n = 15) according to working length determined, G+1 root canal preparation 1 mm beyond the apical foramen, G0 root canal preparation at the major foramen, and G-1 root canal preparation 1 mm short of the major foramen. Five roots were not inoculated to serve as a negative control. Bacteriological samples were collected prior to preparation, initial collection (S1), and after reciprocating instrumentation (S2) by disaggregating biofilm to quantify the reduction of planktonic bacteria and intracanal biofilm at different WL. Bacterial quantitation was performed using colony-forming units per milliliter (CFU / mL) count. Statistical analysis was performed at the significance level of 0.05. Results: No bacterial growth was observed in the negative control. All positive controls demonstrated bacterial growth; S1 from all teeth were positive for bacteria with no significant difference. The post-hoc analysis showed G+1 promoting a significantly higher disinfection than G-1 (p<0,05) and G-1 similar disinfection to G0 (P=962). Conclusion: Instrumentation as close as possible to major foramen or beyond it improves decontamination in oval root canals with reciprocating instrumentation.

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