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

Endodontic Procedural Errors and Associated Factors among Undergraduate Dental Students: A Cross-sectional Study

AIMS AND BACKGROUND

To assess the procedural errors committed by undergraduate students at RAK College of Dental Sciences, during root canal treatments and the factors associated with these errors.

MATERIALS AND METHODS

In this cross-sectional study, 180 self-administered questionnaires were distributed, each comprising 26 questions, among 4th and 5th-year students. Participants were requested to report their endodontic mishaps based on feedback from their supervisors. The questionnaire assessed the frequency and types of procedural errors, considering patient, operator, and tooth-related factors. Data were collected tabulated and analyzed using the Chi-square test.

RESULTS

A total of 124 root canal-treated teeth exhibiting iatrogenic errors done by students were assessed. Out of which, 53% were performed by 5th-year students, and 69% were conducted by female operators. About 62% of errors occurred in the upper teeth and 68% in the posterior teeth. The most prevalent errors during the rubber dam isolation step were soft tissue trauma (21%) and isolation leakage (20%), significantly associated with limited mouth opening, excessive salivation, and tooth malalignment (p < 0.05). Apical blockage (15%) emerged as the most frequent error during instrumentation phase, showing a significant association with canal dimension and curvature (p < 0.05). For access cavity and obturation phases, under-extended cavity (9%), and under-extended filling (11%) were the most reported errors, respectively.

CONCLUSION

Tooth isolation emerges as a particularly challenging aspect for dental students, particularly when dealing with patients exhibiting limited mouth opening and excessive salivation.

CLINICAL SIGNIFICANCE

Clinical instructors should caution the undergraduates about the heightened risk of endodontic procedural errors when dealing with patients exhibiting limited mouth opening, excessive salivation, tooth misalignment, and narrow canals. Addressing these challenges is crucial for enhancing the proficiency of undergraduate students in performing successful root canal treatments. How to cite this article: Elsayed MA, Islam MS, Saleh DR, et al. Endodontic Procedural Errors and Associated Factors among Undergraduate Dental Students: A Cross-sectional Study. J Contemp Dent Pract 2023;24(12):998-1007.

Effect on undergraduate student self-confidence in using 3D printed primary molars for root canal treatment simulation training

PURPOSE

The main purpose of this study was to assess the effect of a root canal treatment (RCT) practical simulation-based session using 3D printed primary molars on the self-confidence of fourth-year undergraduate dental students. Our study was also designed to explore student experiences with both manual and rotary RCT procedures and to investigate the association between the self-confidence in undertaking an RCT and the quality of the RCT.

METHODS

Student global self-confidence in undertaking an RCT on a healthy, cooperative child aged 4-5 years was evaluated 2 h before, 1 month after, and 11 months after the simulation training session. Once each instrumental procedure had been completed, the students were also asked to score the level of confidence (specific self-confidence) they felt regarding the use of RP and MP. After each training session, the quality of the RCT was radiographically evaluated by two trained, independent investigators.

RESULTS

Overall, student global self-confidence in undertaking an RCT increased significantly immediately after the practical session and remained stable for the ensuing eleven months. The students declared a clear preference for RP and were more self-confident in undertaking an RCT after RP than after MP. The proportion of RCTs considered of good quality was the same for the manual (31.5%) and rotary (30.3%) procedures.

CONCLUSIONS

Simulation training is a good way to train dental students who are confident in undertaking RCTs. However, confidence is not directly related to competence. Teachers should be encouraged to develop a comprehensive simulation training program, including feedback, debriefing, and repetitions.

Quality of root canal treatment performed by undergraduate students using nickel-titanium reciprocating versus hand instruments

PURPOSE

To compare the technical quality of root canal treatment (RCT) depending on the incidence of procedural errors performed by undergraduate students using nickel-titanium reciprocating and conventional hand instrumentation techniques, and to assess the impact of case difficulty and localization of the teeth (maxillary or mandibular molars).

METHODS

Dental records and periapical radiographs of molars that were treated with either hand or reciprocating WaveOne (WO) instruments were evaluated retrospectively. The technical quality of RCTs, the incidence of ledge formation, perforation, instrument fracture, overinstrumentation, underfilling, overfilling, inadequate root canal filling, and the effects of case difficulty and tooth localization were compared using the chi-square test with a significance of 5% (α = 0.05).

RESULTS

While overinstrumentation was more frequent in the WO group (247 teeth), the incidence of inadequate root canal fillings was higher in the hand instrumentation group (245 teeth) (p < 0.01). No significant difference was observed in the incidence of other procedural errors (p > 0.05). The number of teeth with acceptable technical quality in preparation and obturation was 172 (69.6%) in the WO group, whereas it was 142 (58%) in the hand instrumentation group, presenting a significant difference between the instrumentation techniques (p < 0.01). Higher technical quality rates were observed with WO instrumentation in the high difficulty category and in maxillary teeth (p < 0.01).

CONCLUSION

Higher technical quality in preparation and obturation can be achieved with WO reciprocating instruments and file-matched greater tapered gutta-percha cones. No significant difference was observed between the groups in the incidence of procedural errors except for overinstrumentation and insufficient root canal filling. WO instrumentation and obturation with file-matched greater tapered gutta-percha cones provided better technical quality in the high difficulty category and in maxillary teeth.

Radiographic assessment of endodontic mishaps in an undergraduate student clinic: a 2-year retrospective study

Objectives

The aim of this study was to compare the occurrence of instrumentation and obturation related endodontic procedural mishaps following the use of either, stainless steel hand or engine-driven rotary instrumentation techniques.

Methods

From a computerized hospital database, a total of 730 dental patient records who had received endodontic treatment by undergraduate dental students between August 2018 to September 2020 were retrieved. The inclusion criteria were primary (non-surgical) endodontic treatment on permanent teeth with complete radiographic records. Following record screening, a final sample of n = 475 dental records were included. Radiographic records were evaluated for both instrumentation and obturation related mishaps. The data was analysed using multiple logistic regression analysis (α = 0.05).

Results

Engine-driven rotary instrumentation resulted in a significant decrease in the overall occurrence of instrumentation related endodontic mishaps by 40% compared to hand instrumentation (Odds Ratio = 0.59 [0.36-0.97], p = 0.04). In particular, rotary instrumentation decreased ledge formation, perforation and obturation related mishaps, with minimal effect on the limitation of zipping.

Conclusion

The use of rotary instrumentation techniques may reduce the incidence of instrumentation and obturation endodontic mishaps in the undergraduate dental clinic.

Influence of operator expertise on glide path and root canal preparation of curved root canals with rotary and reciprocating motions

This study intended to help practitioners selecting the appropriate motion according to their level of expertise for glide path and complete root canal preparation of curved canals in terms of instrument fracture and preparation time. A total of 160 curved root canals (angle >30°, radius <6 mm) were allocated randomly to 4 groups: A/B for expert operators and C/D for nonexpert operators. A/C were shaped with rotary and B/D with reciprocating instruments. Preparation time was registered and compared with Kruskal-Wallis non-parametric test and Dunn's post hoc test. Instrument separation was also registered and compared with chi-square test. A fractographic analysis was performed with scanning electron microscopy. The use of reciprocation motions allowed nonexpert operators to avoid instrument breakage during glide path and to prepare root canals faster. Experts were equally effective in rotary/reciprocating root canal shaping and faster with rotary motions than nonexpert operators, who also fractured significantly more rotary instruments.

Body temperature fatigue behaviour of reciprocating and rotary glide path instruments in sodium hypochlorite solutions alone or combined with etidronate

The aim of the study was to compare cyclic fatigue (CF) resistance of reciprocating and rotary glide path instruments in the presence of irrigation solutions at body temperature. CF resistance of 100 instruments (50 ProGlider and 50 WaveOne Gold Glider) was tested in sodium hypochlorite solutions alone (NaOCl) or in combination with etidronate (NaOCl/HEBP). The CF platform with a simulated canal (curvature = 60°/radius = 3 mm) was submerged in a temperature-controlled bath with the solutions kept at 37 ± 1°C controlled by a precision mercury glass thermometer. Instruments were actioned following manufacturer guidelines, and time to failure was recorded and compared among groups with Weibull analysis. Reciprocating glide path preparation instruments were more resistant to CF than rotary instruments in both irrigation solutions. The irrigation solution did not affect the mean life of ProGlider, but reciprocating instruments lasted significantly longer used in presence of NaOCl compared to NaOCl/HEBP.

Ex vivo shaping ability of reciprocating instruments operated by new users: Reciproc versus WaveOne

OBJECTIVES

To compare two reciprocating NiTi systems operated by novices for use in curved root canals.

METHODS

Fifty mesial roots of extracted mandibular first molars, with 2-2 canal configuration, were scanned with micro-CT and divided into 2 groups according to canal length and curvature: Reciproc and WaveOne. Each system was used to prepare one of the two canals by fourth-year dental students, who were new to reciprocating files and were blinded to the system being used. After another scanning, the pre- and post-instrumentation images were compared 3-dimensionally in software.

RESULTS

Some 43 to 46% of the canal wall area remained un-instrumented. Significantly higher proportions of canals were transported towards the isthmus or furcation aspect than the mesial or external aspect. Mean transported distance was the greatest in the coronal one-third. Remaining dentine wall was the thinnest at the furcal aspect near the middle root region. No significant difference was noted between the two brands in the parameters examined.

CONCLUSIONS

Both brands of reciprocating file left similar amounts of un-instrumented canal wall, and resulted in similar extent of canal transportation.

CLINICAL RELEVANCE

NiTi reciprocating files can safely be used by new users to prepare curved root canals into a predictable shape.

Undergraduate Students' Acceptance of a Reciprocating One-File System for Endodontic Treatment

OBJECTIVES

Reciprocating endodontic one-file systems are a comparatively new method for root canal shaping. Even though the mechanical properties are comparable to modern rotating mechanical systems, data about subjective assessment and application quality are scarce. This study evaluates the reciprocating one-file system in undergraduate education.

MATERIALS AND METHODS

A total of 42 undergraduate students without experience regarding reciprocating file systems filled in a questionnaire in four different points in time (t ₁-t ₄) anonymously. The questionnaire was based on a numerical rating scale ranging from 0 to 10.

STATISTICAL ANALYSIS

A least significant difference post-hoc analysis comparing the group average values was performed. The adjusted level of significance was p < 0.004 after Bonferroni correction.

RESULTS

All rating scores increased after the first theoretical instruction. After the first practical training in artificial root canals in resin blocks and extracted teeth (t ₂), the estimation of "time efficiency" (p = 0.002), "handling" (p < 0.001), and "overall impression" (p < 0.001) improved significantly. The "overall impression" remained constant and showed no significant changes after the first practical training.

CONCLUSIONS

Reciprocating systems seem to show a good acceptance among first time users. Initial concerns about "work safety" decrease during every step of the educational process. Reciprocating one-file systems are a safe and well-accepted method in undergraduate teaching.

A comparative study of root canal shaping using protaper universal and protaper next rotary files in preclinical dental education

Background

Dentistry has undergone an evolution in endodontics practice caused by the advancement of rotary techniques for root canal preparation and their subsequent incorporation into the teaching of dentistry undergraduates. This research aimed to evaluate the shaping ability of third-year dental students as their first experience in rotary instrumentation using ProTaper Universal (PTU) and ProTaper Next (PTN) (Dentsply Maillefer) rotary instruments in simulated curved canals.

Methods

Forty students instrumented 200 simulated canals with a 40° curvature in resin blocks according to the manufacturer’s instructions with PTU and 39 students and 195 canals with PTN files. The canals were prepared at a speed of 300 rpm using a 16:1 reduction hand-piece powered by an electric motor (Xsmart; Dentsply Maillefer). The final apical preparation was set to F2 for the PTU and X2 for the PTN group. The change in canal curvature was evaluated based on Schneider technique using the AutoCAD 2007 software on post-digital photographs. The incidence of instrument fracture and deformation, the incidence of ledge, the change in working length (WL), and the working time were noted. The data were analyzed with Student’s t-test and Chi-Square test at a significance level of 0.05 using SPSS.

Results

PTN maintained the original canal curvature better, resulting in fewer fractures and ledges, and shaped the canals faster than the PTU (P < 0.05). The mean curves of the resin canals after the instrumentation for the PTU and PTN groups were 24.03° ± 3.14° and 25.64° ± 2.72°, respectively. Thirty-three (17.4%) PTU and 18 (9.3%) PTN files fractured (p < 0.05). Nine (4.5%) PTU and 2 (2.6%) PTN deformed (p > 0.05). The change in WL after instrumentation was 0.97 mm ± 0.95 mm in PTU and 0.96 mm ± 0.80 mm in PTN (p < 0.05). The mean times were 627 s ± 18 s for PTU and 379 s ± 18 s for PTN (p < 0.000).

Discussion

PTN can be recommended in severely curved root canals in terms of maintenance of the original canal curvature, superior instrument fracture and fewer ledges. Even if training before preparation provides an acceptable level of canal shaping for preclinical students, the use of NiTi rotary instruments should be included in the undergraduate dental curriculum, contributing to an increase in the quality of root canal shaping and, consequently, to an improvement of the clinical experience of students.

A comparative study of mechanical resistance of two reciprocating files

Background

To evaluate the cyclic fatigue resistance of two different Nickel-Titanium instruments, Reziflow (Komet, Brasseler GmbH & Co., Lemgo, Germany) and WaveOne Gold (Dentsply Maillefer, Ballaigues, Switzerland).

Material and Methods

Two groups of 20 different NiTi endodontic instruments of identical tip size of 0.25 mm were tested; Reziflow and Wave-One Gold primary. Cyclic fatigue testing was performed in a stainless steel simulated root canal manufactured by reproducing the instrument’s size and taper. A simulated root canal with a 90 degrees angle of curvature and 5 mm radius of curvature was constructed for the instruments tested. The centre of the curvature was 5 mm from the tip of the instrument and the curved segment of the canal was approximately 5 mm in length. Both the instruments were used in the same preset program specific for the WaveOne instruments. Each instrument was rotated until fracture occurred and the time to fracture (TtF) and the length of the fractured fragment were recorded. Means and standard deviations of TtF and fragment length were calculated and data were subjected to statical analysis (P<0.05).

Results

Statistically significant differences (P<0.05) were noted between Reziflow and WaveOne Gold instruments. There were no significant differences (P>0.05) in the mean length of the fractured fragments between the instruments.

Conclusions

Rezifllow instruments were associated with a significantly higher cyclic fatigue resistance than WaveOne Gold instruments.

Key words:Endodontic instruments, NiTi alloy, Reciprocating motion, Cyclic Fatigue, Heat treatment.

Undergraduate dentistry students' perception of difficulties regarding endodontic treatment

The present study aimed to identify students' perceptions of endodontic treatment at a Brazilian university through a survey, which analysed student profiles and their difficulties in 2016. One hundred and two students who had experienced endodontic, laboratory or clinical procedures answered a survey based on their experiences, regarding their perceptions, experience and self-confidence levels. Results demonstrated that there was no significant difficulty among students regarding anaesthesia, rubber dam use, chamber access, working length determination, instrumentation, root filling and temporary restoration procedures during endodontic treatment. However, problems were observed regarding radiographic examination (mainly in separating root canals) and the choice of intracanal medication. The present study also raised a question regarding dental education: how can endodontic education be improved by addressing students' perceived difficulties? Evaluating the major student difficulties during root canal therapy can help the improvement of teaching strategies during preclinical and clinical teaching.

In vitro resistance to fracture of two nickel-titanium rotary instruments made with different thermal treatments

Aim

Aim of the study was to evaluate effectiveness of different heat treatments in improving Ni-Ti endodontic rotary instruments' resistance to fracture.

Methods

24 new NiTi instruments similar in length and shape: 12 M3 instruments, tip size 25 and .06 taper (United Dental, Shanghai, China), and 12 M3 Pro Gold instruments tip size 25 and .06 taper (United Dental, Shanghai, China), were tested in a 60° curved artificial root canal. Each group received a different heat treatment. Cycles to fracture were calculated for each instrument. Differences among groups were evaluated with an analysis of variance test (significance level was set at P<0.05.).

Results

Statistical analysis found significant differences (p<0.0213) between groups. The M3 Pro Gold instruments were significantly more resistant to fatigue (mean values = 1012, SD +/- 77) than M3 instruments (mean values = 748, SD +/- 62). No statistically significant differences were found between fragments' lengths (p>0,05).

Conclusions

An increased flexibility and the reduction of internal defects produced by heat treatments during or after manufacturing processes, may be responsible for improving resistance to cyclic fatigue and flexural stresses.