Effect of different retreatment files using different kinematics on the release of inflammatory mediators in root canal retreatment of single-rooted teeth: a randomized clinical trial

OBJECTIVES

This randomized clinical trial aimed to evaluate the effect of two rotaries (ProTaper Universal Retreatment (PTUR)), D-Race (DR) + XP-Endo Finisher R (XPFR) and one reciprocating (Reciproc Blue (RB) retreatment techniques on the release of neuropeptides (Substance P, calcitonin gene-related peptide (CGRP)), and cytokines (IL-6 and IL-10) in periapical fluid in root canal retreatment of single-rooted teeth.

MATERIALS AND METHODS

In this randomized clinical trial (ClinicalTrials.gov ID: NCT05039502), seventy-five patients scheduled for retreatment were randomly divided into 3 groups according to the file system used to remove root canal filling materials (n = 25): PTUR, RB, and DR + XPFR. After reshaping and disinfection of the root canals, periapical fluid samples were taken, and the levels of Substance P, CGRP, IL-6, and IL-10 were measured by enzyme-linked immunosorbent assay (ELISA) test. Data were analyzed using the Kruskal-Wallis and chi-square tests. The level of significance was set as p = 0. 05.

RESULTS

All the allocated participants received the intervention and were analyzed. There was no statistically significant difference among groups in terms of gender, age, tooth localization, and the distribution of analgesic use after treatment (p values 0.799, 0.095, 0.637, 1.000, respectively). No statistically significant difference was found in terms of the levels of Substance P, CGRP, and IL-10 among groups (p > .05), except IL-6.

CONCLUSIONS

PTUR, RB, and DR + XPFR files have comparable results in the expression of inflammatory mediators.

CLINICAL RELEVANCE

Retreatment files powered with rotary or reciprocating motion produced similar neuropeptide and cytokine levels in patients.

Efficiency of the new reciprocating and rotary systems with or without ultrasonics in removing root-canals filling with calcium silicate-based sealer (MTA)

BACKGROUND

To compare the efficiency of endodontic rotary and reciprocating systems in removing calcium silicate-sealer based fillings and to investigate the impact of passive ultrasonic irrigation (PUI) on their efficiency.

MATERIALS AND METHODS

160 root-canals were instrumented, filled with gutta-percha and calcium silicate based-sealer and divided into 10 equal groups. Five groups in which the reciprocating systems (WaveOne-Gold, Reciproc-Blue and R-Motion) and rotary systems (Fanta-AF-One and Tango-Endo) were used to remove root-canals' fillings. In the other five groups the fillings were removed by the same systems then additionally with PUI. The times to complete retreatments procedures were recorded. Micro-computed tomography's analysis of the root-canals fillings' volume before and after retreatments was used to determine the remaining filling materials (RFMs) volumes.

RESULTS

The RFMs after using rotary systems (10.1%) was greater than after using reciprocating systems (3.8%) (P < 0.001). The RFMs after using WOG (2%) and RB systems (2.6%) were less than those in the RM (6.8%), TE (9.5%) and FAFO (10.7%) systems [P < 0.05]. The times required to remove the filling materials using the TE (3.7 min), FAFO (4.1 min) and RM (4.1 min) systems were shorter than those required by the RB (5.4 min) and WOG (4.9 min) systems [P < 0.05]. Using PUI resulted in less RFMs (1.44%) when compared to using only rotary or reciprocating systems (6.27%) [P < 0.001].

CONCLUSIONS

Endodontic reciprocation systems were more effective, but needed longer times than rotary systems in removing calcium silicate based- sealers fillings. The PUI significantly improved removal of the root-canals' filling materials.

CLINICAL RELEVANCE

Reciprocating systems and PUI are recommended whenever root-canals retreatment is considered regardless of using calcium silicate-based sealers.

Treatment outcome of tardy ulnar nerve palsy associated with traumatic cubitus valgus by supracondylar shortening wedge rotary osteotomy and ulnar nerve in situ tension release

Background

Tardy ulnar nerve palsy is a common late complication of traumatic cubitus valgus. At present, the treatment of tardy ulnar nerve palsy associated with traumatic cubitus valgus is still controversial, whether these two problems can be corrected safely and effectively in one operation is still unclear. To investigate the supracondylar shortening wedge rotary osteotomy combined with in situ tension release of the ulnar nerve in the treatment of tardy ulnar nerve palsy associated with traumatic cubitus valgus.

Methods

Between 2012 and 2019, 16 patients who had traumatic cubitus valgus deformities with tardy ulnar nerve palsy were treated with simultaneous supracondylar shortening wedge rotary osteotomy and ulnar nerve in situ tension release. we compared a series of indicators of preoperative and postoperative follow-up for at least 24 months, (1) elbow range of motion; (2) the radiographic correction of the preoperative and postoperative humerus-elbow-wrist angles; (3) the static two-point discrimination and grip strength; and (4) the preoperative and postoperative DASH scores of upper limb function. The minimum follow-up was 24 months postoperative (mean, 33 months; range, 24 ~ 44 months).

Results

The mean ROM was improved from 107 ° preoperatively to 122 ° postoperatively (P = 0.001). The mean preoperative elbow wrist angle was 24.6 °, and the mean postoperative humerus-elbow wrist angle was 12.1 ° (P < 0.001). The average grip strength and static two-point discrimination improved from 21 kgf and 8 mm to 28 kgf and 4.0 mm (P < 0.001 and P < 0.001, respectively). The ulnar nerve symptoms were improved in all patients except one. The mean HASH score improved from 29 to 16 (P < 0.001).

Conclusion

Supracondylar shortening wedge rotary osteotomy combined with in situ tension release of ulnar nerve is an effective method for the treatment of traumatic cubitus valgus with tardy ulnar nerve palsy, which restored the normal biomechanical characteristics of the affected limb and improved the elbow joint function.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-022-05324-7.

Differential scanning calorimetric investigations of three rotary nickel-titanium instrument systems before and after simulated clinical uses

BACKGROUND

The transformation temperatures were important values, influencing the mechanical properties and clinical performance of nickel-titanium instruments. The aim of this study was to determine the transformation temperatures of three rotary nickel-titanium (NiTi) instruments: Reciproc, HyFlex CM Pro, and Neoniti before and after simulated clinical uses.

METHODS

Ninety new NiTi instruments of three single-file instruments: Reciproc, HyFlex CM Pro, and Neoniti were divided into three groups. Thirty instruments of each group were divided into 3 subgroups (10 instruments for each subgroup): new, one-time simulated clinical used and sterilised, and three times simulated clinical used and sterilized subgroups. The instruments were in the as-received condition for the new subgroups, one time used in the plastic endo-training blocks and sterilised for the one-time subgroups, and three times used in the plastic endo-training blocks and sterilised for the three times subgroups. Each instrument in subgroups was cut into four small segments of 4-5 mm. All segments of instruments were analysed using Differential Scanning Calorimetry (DSC). Data was collected and analysed using SPSS version 20.0 with ANOVA test or Kruskal-Wallis test at the significant level of 0.05.

RESULTS

There was not significant difference between before and after simulated clinical use with sterilised procedure in three NiTi instrument systems. The austenite-finish (A_f) temperatures of three instrument systems were higher than that of the human body (37 °C), of these, the A_f temperature of Neoniti was highest and that of HyFlex CM Pro was lowest.

CONCLUSIONS

The austenite-finish (A_f) temperatures of three NiTi instruments were higher than that of human body temperature, therefore, material was in the phase transformation from martensite to austenite, gives the instruments more flexibility when used in the clinical situation.

Shaping ability of three nickel-titanium rotary instruments in simulated L-shaped canals: OneShape, Hero Shaper, and Revo-S

Background

Shaping ability of a file plays an important role during instrumentation in an endodontic treatment. This study aimed to compare the shaping ability of OneShape (OS), Hero Shaper (HS), and Revo-S (RS) instruments in simulated L-shaped canals.

Methods

Forty-eight simulated L-shaped canals were prepared to an apical size of 25 using OS, HS, and RS (all from Micro-Mega SA, Besançon, France), (n = 16 canals/group) systems. The amount of resin removed after each canal's preparation was measured and compared after producing a composite image made from the superimposition of pre and post-instrumented canals. Canal aberrations and the preparation time were also recorded. The data were statistically analysed by using ANOVA, Tukey, and Chi-square tests.

Results

One file fractured during instrumentation in the RS group. A significant difference was found at the apical end of the prepared simulated canal between the groups, with RS showing the least amount of resin removal from the inner side of the canals and HS showing the highest amount of resin removal from the outer side (P < 0.05). Regarding the total width of the canals after preparation, a significant difference was found between the groups at the apical end and the straight portion of the canals, and RS removed the least amount of resin at the straight portion of the canals (P < 0.05). No statistically significant differences were found between the different instruments regarding canal aberrations' incidence (P > 0.05).

Conclusions

All of the files showed a tendency to straighten the canals, whereas OS files maintained the original canal curvatures well.

Factors influencing incidents of complications while using nickel-titanium rotary instruments for root canal treatment

Background

To investigate the complications associated with the use of nickel titanium rotary instruments (NiTi-RIs) for root canal treatments (RCTs), in Saudi Arabia dental practice, and to explore the influencing factors.

Methods

After obtaining an ethical approval, two pilot studies were conducted to formulate the final questionnaire. The sample size was measured taking into consideration 60% expected response rates and confidence level of 99.9%. The questionnaire was emailed to 600 general dentists (GDs) randomly selected from the dental register and all of the endodontists (175). The email’s introduction clarified objectives of the study and guaranteed that all of the collected information would remain confidential. A reminder was sent after 10 weeks. The data were collected and analyzed using the chi-squared test at a 0.05 significance level.

Results

With a 51% overall response rate, 71.9% off the respondents used NiTi-RIs. The majority (83.1%) experienced complications while using NiTi-RIs; with the instruments’ fracture being significantly the most common complication (52.7%) (p < 0.001). The majority (87.7%) experienced NiTi-RIs’ fractureat least once; with more endodontists (94.3%) than GDs (83.3%) (p < 0.001). The greater the number of weekly performed RCTs and participants’ experiences, the more NiTi-RIs fractures and the greater the number of fracture incidents (p < 0.001). While 60% of those who performed 1–3 RCTs per week experienced NiTi-RIs fractures, 100% of those who performed more than 12 RCTs per week did so. The highest percentage of those who experienced more than 10 fractured NiTi-RIs (60%) was within the group who performed more than 12 RCTs per week. Although fracture incidents decreased with a smaller number of reuses, there was no significant correlation between the number of fractured instruments and NiTi-RIs discard strategy (p ≥ 0.05).

Conclusion

Fracture incidence was the most common complication while using NiTi-RIs, regardless of the clinicians’ experiences and skills. While the single use may reduce NiTi-RIs fractures, to some extent, the greater number of RCTs performed per week was the most influential factor.

The influence of kinematics of engine-driven nickel-titanium instruments on root canal shape assessed by micro-computed tomography: a systematic review

AIM

To evaluate if the kinematics of engine-driven instruments affect the root canal shape.

METHOD

The systematic review was registered in PROSPERO (CRD 42017077043). A broad search was performed for articles published before 26 September 2018 in the electronic databases: pubmed, scopus, web of science and Lilacs using MeSH and free terms. Only in vitro studies with human teeth that evaluated root canal shape by volume, surface area and unprepared surface area using reciprocating and rotary system assessed by micro-computed tomography were included. A modified checklist for randomized controlled trials from the Joanna Briggs Institute was used to assess the risk of bias.

RESULTS

Twenty-one articles were selected. According to quality assessment, all studies were considered 'moderate methodological quality'. Eighteen articles analysed volume increase, only four studies showed statistically significant difference, three indicating that the reciprocating movement obtained a greater increase in volume than the rotary system and one rotary system obtained a greater increase. Twelve studies analysed surface area, only three studies showed statistically significant difference, two presented a reciprocating system revealing greater amount of surface area and one showed a rotary system obtained a greater amount of surface area. Ten articles evaluated unprepared surface area, two studies that analysed total length, one study presented that the rotary system revealed lower unprepared surface area while another study showed reciprocating with less unprepared area. One study analysed middle and apical third, and observed that the rotary system presented lower unprepared surface area in the middle third.

CONCLUSIONS

Both the rotary and reciprocating kinematics produce changes in volume and surface area and leave unprepared areas in the root canal, however reciprocating system showed greater increase of volume and surface area, while the rotary system maintains less unprepared surface area.

An Ex Vivo Evaluation of Antimicrobial Efficacy of Root Canal Preparation With Hand K-Files, Hand Pro Taper, and Pro Taper Rotary Files

Background:

Microorganisms are considered to be the primary cause behind persistent pulpoperiapical pathologies as well as endodontic failures. It has been found that Enterococcus faecalis is one of the most commonly isolated organisms in failed endodontic treatment. Proper and appropriate mechanical instrumentation is necessary to eradicate these microorganisms.

Aims and Objectives:

The aim of this study was to compare antimicrobial efficacy of various root canal instrumentation techniques. This study was designed to compare antimicrobial efficacy of root canal preparation using hand K-files, hand Pro Taper files, and Pro Taper rotary files.

Materials and Methods:

Forty intact maxillary premolars extracted for orthodontic reasons were used. After extirpation of pulp, teeth are decoronated and autoclaved. Then the root canals were infected with E. faecalis suspension and the teeth were incubated at 37°C for 24 h. Thereafter the teeth were divided into five groups and were prepared using the following instruments: group 1 (hand K-files), group 2 (hand Pro Taper files), group 3 (Pro Taper rotary files), group 4 (Control I; treatment consists of irrigation with 1 mL of sterile physiological saline with no instrumentation), and group 5 (Control II; teeth received no treatment at all). Before and after treatments, samples were taken from the root canals for culture and were transferred to physiological saline. Results were evaluated after 24-h incubation in selective culture medium.

Results:

The results showed that the teeth prepared with Pro Taper rotary files showed significant reduction in number of bacteria from the root canals.

Comparative evaluation of instrumentation timing and cleaning efficacy in extracted primary molars using manual and NiTi rotary technique - Invitro study

Aim

To compare the timing of instrumentation and cleaning efficacy between manual K files and NiTi rotary files in extracted primary molars.

Study design

in-vitro study was conducted in 90 root canals of extracted primary molars which were subdivided in three groups viz. Control (No instrumentation), Manual (K files), Rotary (ProFiles) with 30 canals in each group. Mesiobuccal (MB) and Mesiolingual (ML) canals of mandibular molars, and MB and Distobuccal (DB) canals of maxillary molars were included in the test group whereas Distal canals in mandibular molars and Palatal canals in maxillary molars were included in the control group.

Method

Teeth were mounted and canals were injected with India ink to stain the canal walls. Canal preparation was done as per the group. After instrumentation, teeth were demounted, decalcified and cleared to make them transparent for scoring according to the extent of removal of India ink. Timing of instrumentation and cleaning efficacy of canals in coronal, middle and apical thirds were assessed in each sample.

Results

Mean timing of instrumentation in rotary group was 3.54 ± 1.14 min and 4.32 ± 1.04 min in manual group. Mean cleaning efficacy scores in manual and rotary groups were 2.03 and 1.66 in coronal third, 1.08 and 1.18 in middle third and 0.67 and 1.08 in apical third respectively. Inter-group comparisons showed no statistically significant difference in cleaning efficacy among test groups in all thirds of root canals.

Conclusion

NiTi rotary technique has comparable cleaning efficacy, with significantly less timing of instrumentation compared to manual K-files.

Separation of Nickel-Titanium Rotary and Reciprocating Instruments: A Mini-Review of Clinical Studies

Objective:

This review aimed to evaluate clinical studies that assessed separated NiTi rotary and reciprocating instruments.

Design and Methods:

This review assessed clinical studies involving treatments performed by undergraduate students, graduate students, and endodontic specialists. This review evaluated studies using rotary instruments, reciprocating instruments, and hybrid techniques. The number of uses of the different NiTi rotary and reciprocating systems was also assessed.

Results:

The incidence of separation for rotary instruments ranged from 0% to 23%. Rotary instruments were used from 1 to 50 times depending on the instrument and tooth type. The lowest rate of incidence separation for rotary instruments was obtained by undergraduate students, using a hybrid technique. The separation incidence for reciprocating instruments ranged from 0% to 1.71%. Reciprocating instruments were mostly single-used; one study reported their use up to 3 times. Separation rate in reciprocating instruments was similar in single-use or in multiple uses 0.2%.

Conclusions:

Separation of instruments has dropped recently and seems to be a minor problem in current Endodontics. Multiple uses of NiTi rotary instruments are a possibility without significantly increasing the risk of instrument separation. Single and multiple uses of NiTi reciprocating instruments are also associated with low incidence of separation. Attempting to remove separated instruments should be carefully evaluated.

Comparative Evaluation of Surface Defects In Single File Rotary Systems Before and After Instrumentation In Curved Root Canals

This study aims to evaluate the surface defects and efficiency of two single file rotary systems with different surface treatments in curved root canal instrumentation. A total of 160 root canals were randomly divided into two groups and were subjected to root canal instrumentation with electropolished surface rotary file (Group 1) and with EDM surface treated rotary file (Group 2). All the files were then subjected to SEM analysis to evaluate the surface defects prior to the root canal instrumentation,after 5 uses and 8 uses inside the root canal. From the scanning electron microscopic images, the surface defects as observed were scored and were statistically analyzed. SEM analysis of both the single file systems revealed significantly varying surface defects. Rotary file with electropolishing appeared to be more resistant to deformation compared to the rotary file with EDM treatment after instrumentation of five canals. Hence it can be concluded that electropolished file can be safely instrumented for five times compared to EDM processed files in curved root canals.

TREATMENT OUTCOME OF MANUAL VERSUS ROTARY TECHNIQUES IN SINGLE-VISIT ENDODONTICS FOR PATIENTS IN A NIGERIAN TEACHING HOSPITAL: A RANDOMIZED CLINICAL TRIAL

BACKGROUND

Adequate canal preparation is essential in achieving successful outcome sequel to root canal treatment. Nickel-Titanium (NiTi) rotary instruments has steadily gained grounds in endodontics for root canals preparation, however, it is yet to be widely practiced among dental practitioners in Nigeria.

AIM AND OBJECTIVES

To compare the treatment outcomes of single visit root canal treatment when either rotary or manual step-back preparation technique is used in shaping the canal, employing clinical and radiographic criteria.

DESIGN OF THE STUDY

A randomized controlled trial.

SETTING

Conservation Unit of Restorative Dentistry Clinics, Lagos University Teaching Hospital (LUTH), Lagos, Nigeria.

MATERIALS AND METHODS

120 consecutive consenting subjects were included in the study. The inclusion criteria were: medically fit individuals with restorable anterior, premolar or first molar tooth diagnosed with irreversible pulpitis, pulp necrosis or apical periodontitis; they had no to moderate pain, with periodontally sound and not excessively curved tooth. Randomization was performed by balloting using sealed envelopes and subjects were assigned in equal numbers to one of two groups, rotary and manual. Subjects were monitored following treatment for clinical and radiographic parameters at 1 day, 1 week, 1 month, 3 months and 6 months. Data analysis was done using SPSS-version 20.0, and differences were considered significant if p < 0.05.

RESULTS

Twenty-seven (45%) and 23(38.3%) teeth in manual and rotary group respectively had pain at 1-day review. Significant difference in occurrence of pain in relation to both gender (p=0.001) and tooth-type (p=0.026) was noted between the groups at 1-day review. By the final review, there was no reported post-operative pain. There was no significant difference between the two groups in relation to the other clinical parameters at the different review periods. Twenty-four (40%) and 16 (26.7%) teeth had pre-existing periapical radiolucency in manual and rotary groups respectively; by final review, periapical radiolucency had reduced to 16.9% and 3.4% respectively, with the rotary group having significantly less radiolucency. Favourable outcome at 6-month review was significantly higher in the rotary group (96.6%), compared to the manual group (83.1%) in (p=0.033); the difference in outcome was due to significantly better outcomes with the molar tooth category in the rotary group.

CONCLUSION

There was a significantly more favourable treatment outcome in the rotary compared to the step-back technique in canal preparation, employing clinical and radiographic criteria.

The Effect of Root Canal Preparation Using Single Versus Multiple Endodontic Rotary Files on Post-operative Pain, a Randomised Clinical Trial

Objective:

The purpose of this randomised clinical trial study was to compare the incidence and intensity of post-operative pain following the use of single-file and multi-file rotary instruments with continuous rotational motion for root canal preparation in asymptomatic permanent human teeth.

Methods:

A total of 105 healthy consenting patients who fulfilled specific inclusion criteria and had premolar or molar teeth diagnosed with asymptomatic irreversible pulpitis without periapical pathosis requiring endodontic treatment participated in this study. The patients were randomly allocated by stratification into five groups of 21 according to the instruments and systems used for root canal preparation: (a) Neoniti A1 (#25) single file, (b) RaCe #25/.06 single file, (c) Mtwo #25/.06 single file, (d) Easy RaCe, (e) and Mtwo multifile. Endodontic treatment was carried out in a single appointment. The severity of post-operative pain was assessed by numerical rating scale scores until complete pain relief was achieved. Analgesic consumption and the incidence of pain were also evaluated. Data were analysed by one-way ANOVA and Tukey HSD tests.

Results:

When comparing different instruments and systems for canal preparation, the analgesic consumption, incidence and intensity of post-operative pain did not differ (p>0.05). The highest levels of post-operative pain were experienced after 6 h in all groups.

Conclusion:

The post-operative pain did not differ between the single and multi-file root canal preparation techniques evaluated in this study.

Rotary's PolioPlus Program: Lessons Learned, Transition Planning, and Legacy

Hundreds of thousands of Rotary volunteers have provided support for polio eradication activities and continue to this day by making financial contributions to the Rotary PolioPlus program, participating in national immunization days, assisting with surveillance, working on local, national, and international advocacy programs for polio eradication, assisting at immunization posts and clinics, and mobilizing their communities for immunization activities (including poliovirus and other vaccines) and other health benefits. Rotary has contributed more than $1.61 billion for the global eradication of polio and has committed to provide an additional $35 million each year until 2018 (all dollar amounts represent US dollars). Its unwavering commitment to eradicate polio has been vital to the success of the program. Rotary is providing additional support for routine immunization and healthcare. When polio is finally gone, we will have the knowledge from the lessons learned with PolioPlus, such as the value of direct involvement by local Rotarians, the program for emergency funding, innovative tactics, and additional approaches for tackling other global issues, even those beyond public health. Rotary has already transitioned its grants program to include 6 areas of focus: disease prevention and treatment, water and sanitation, maternal and child health, basic education and literacy, economic and community development, and peace and conflict prevention/resolution. Funding for these grants in 2015–2016 was $71 million. The legacy of the polio program will be the complete eradication of poliovirus and the elimination of polio for all time.

Comparison of apical debris extrusion during root canal preparation using instrumentation techniques with two operating principles: An in vitro study

Aims:

The aim of this study was to quantify the debris extruded apically from teeth using rotary and reciprocation instrumentation systems.

Subjects and Methods:

Eighty extracted human mandibular premolars with single canals and similar lengths were instrumented using ProTaper Universal (40, 06; Dentsply Maillefer, Ballaigues, Switzerland), ProTaper Next (40, 06; Dentsply Maillefer, Ballaigues, Switzerland), WaveOne (40, 06; Dentsply Maillefer, Ballaigues, Switzerland), and Reciproc (R40; VDW GmbH, Munich, Germany). Debris extruded during instrumentation was collected into preweighed Eppendorf tubes, which were then stored in an incubator at 70°C for 5 days. The final weight of the Eppendorf tubes with the extruded debris was calculated after obtaining the mean of three consecutive weights obtained for each tube.

Statistical Analysis Used:

Statistical analysis was performed using SPSS version 16.0 software. The groups were compared using the Kruskal–Wallis test for all variables.

Results:

There was no statistically significant difference between the groups (P = 0.1114). However, the ProTaper Universal group produced more extrusion and ProTaper Next produced least debris extrusion among the instrument groups (P > 0.05).

Conclusions:

All instrumentation techniques were associated with extruded debris.

Shaping of the Root Canal System: A Multistep Technique

AIM

The aim of this scientific work is to illustrate the technique of shaping the root canal system using the multistep technique.

BACKGROUND

Over time, various endodontic instrumentation techniques have been put forward, from the "step-back" technique (apical-coronal) to the "crown-down" technique (coronal-apical), the "double-flared" technique, and the most recent "single-length" technique.

TECHNIQUE

The multistep technique involves six steps, one of the main objectives of these being the safety of the use of mechanical instruments with a reduction in the risk that they fracture. This technique ("mixed") provides for the use of both manual instruments in stainless steel and mechanical instruments in nickel titanium (Ni-Ti).

CONCLUSION

The multistep technique is based on a standardized, flexible, and clinical protocol, which can provide for a reduction in the number of endodontic passages and instruments used and, therefore, a simplification of the operating procedure depending on both the difficulty of the root canals and the competence of the operator.

CLINICAL SIGNIFICANCE

This technique is a technique for shaping the endodontic space that allows the set objectives of endodontic therapy to be reached in a predictable way with a reduced risk of iatrogenic complications.

Post endodontic pain following single-visit root canal preparation with rotary vs reciprocating instruments: a meta-analysis of randomized clinical trials

Background

In endodontic therapy, continuous rotary instrumentation reduced debris compared to reciprocal instrumentation, which might affect the incidence of post-endodontic pain (PP). The aim of our study was to assess whether PP incidence and levels were influenced by the choice of rotary or reciprocal instruments.

Methods

In this meta-analysis the Pubmed and EM databases were searched for prospective clinical randomized trials published before April 20, 2016, using combinations of the keywords: root canal preparation/instrumentation/treatment/therapy; post-operative/endodontic pain; reciprocal and rotary instruments.

Results

Three studies were included, involving a total of 1,317 patients, 659 treated with reciprocating instruments and 658 treated with rotary instruments. PP was reported in 139 patients in the reciprocating group and 172 in the rotary group. The PP incidence odds ratio was 1.27 with 95% confidence interval (CI) (0.25, 6.52) favoring rotary instruments. The mild, moderate and severe PP levels odds ratios were 0.31 (0.11, 0.84), 2.24 (0.66, 7.59) and 11.71 (0.63, 218.15), respectively. No evidence of publication bias was found.

Conclusions

Rotary instrument choice in endodontic therapy is associated with a lower incidence of PP than reciprocating instruments, while reciprocating instruments are associated with less mild PP incidence.

Cleaning Effectiveness of a Reciprocating Single-file and a Conventional Rotary Instrumentation System

Objective:

To compare cleaning effectiveness by histological analysis of a reciprocating single-file system with ProTaper rotary instruments during the preparation of curved root canals in extracted teeth.

Methods:

A total of 40 root canals with curvatures ranging between 20 - 40 degrees were divided into two groups of 20 canals. Canals were prepared to the following apical sizes: Reciproc size 25 (n=20); ProTaper: F2 (n=20). The normal distribution of data was tested by the Kolmogorov-Smirnov test and the values obtained for the test (Mann-Whitney U test, P < .05) were statistically analyzed using the GraphPad InStat for the Mac OS software (GraphPad Software, La Jolla, CA, USA).

Results:

There were no significant differences in remaining debris (P > .05) between the two groups.

Conclusion:

The application of reciprocating motion during instrumentation did not result in increased debris when compared with continuous rotation motion, even in the apical part of curved canals. Both instruments resulted in debris in the canal lumen, irrespective of the movement kinematics applied.

Preference of undergraduate students after first experience on nickel-titanium endodontic instruments

Objectives

This study aimed to compare two nickel-titanium systems (rotary vs. reciprocating) for their acceptance by undergraduate students who experienced nickel-titanium (NiTi) instruments for the first time.

Materials and Methods

Eighty-one sophomore dental students were first taught on manual root canal preparation with stainless-steel files. After that, they were instructed on the use of ProTaper Universal system (PTU, Dentsply Maillefer), then the WaveOne (WO, Dentsply Maillefer). They practiced with each system on 2 extracted molars, before using those files to shape the buccal or mesial canals of additional first molars. A questionnaire was completed after using each file system, seeking students' perception about 'Ease of use', 'Flexibility', 'Cutting-efficiency', 'Screwing-effect', 'Feeling-safety', and 'Instrumentation-time' of the NiTi files, relative to stainless-steel instrumentation, on a 5-point Likert-type scale. They were also requested to indicate their preference between the two systems. Data was compared between groups using t-test, and with Chi-square test for correlation of each perception value with the preferred choice (p = 0.05).

Results

Among the 81 students, 55 indicated their preferred file system as WO and 22 as PTU. All scores were greater than 4 (better) for both systems, compared with stainless-steel files, except for 'Screwing-effect' for PTU. The scores for WO in the categories of 'Flexibility', 'Screwing-effect', and 'Feeling-safety' were significantly higher scores than those of PTU. A significant association between the 'Screwing-effect' and students' preference for WO was observed.

Conclusions

Novice operators preferred nickel-titanium instruments to stainless-steel, and majority of them opted for reciprocating file instead of continuous rotating system.

Rotary endodontics in primary teeth - A review

Endodontic treatment in primary teeth can be challenging and time consuming, especially during canal preparation, which is considered one of the most important steps in root canal therapy. The conventional instrumentation technique for primary teeth remains the "gold-standard" over hand instrumentation, which makes procedures much more time consuming and adversely affects both clinicians and patients. Recently nickel-titanium (Ni-Ti) rotary files have been developed for use in pediatric endodontics. Using rotary instruments for primary tooth pulpectomies is cost effective and results in fills that are consistently uniform and predictable. This article reviews the use of nickel-titanium rotary files as root canal instrumentation in primary teeth. The pulpectomy technique is described here according to different authors and the advantages and disadvantages of using rotary files are discussed.