Effect of self-assessment training in preclinical endodontic courses on the clinical performance of undergraduate dental students

BackgroundRoot canal treatment (RCT) of molar teeth is very challenging to undergraduate dental students. Well-structured self-assessment was shown to be the key for improving quality of dental education so that graduates could be properly prepared to act independently in dental practice.AimsTo observe the effect of rubric self-assessment teaching during the preclinical stage on the performance of undergraduate students in treating patients’ molars. Methods An improved rubric was introduced to the endodontic preclinical stage through which 128 students were trained on self-assessing their practical work over an entire year (Group A). While 149 students (Group B) were taught without self-assessment. The following year, during the clinical stage, both groups were asked to treat single rooted teeth only, after they finish at least ten teeth, students who feel confident enough were allowed to do simple molar cases. The effect of new system on the ability of undergraduate students to perform root canal treatment on patients’ molars was studied.Results All students taught on self-assessment where able to perform RCT on patients’ on molars before graduation (100 per cent) in comparison to 73.83 per cent for the students of the previous groups. There was statistically significant difference for the average number of molars treated per student: 6.06 for Group A in comparison to 3.00 for Group B. All analysis was performed with 0.05 level of set significance using the statistical software SPSS 16.0 for Windows.ConclusionWhen cases are properly selected, ttechnical part of root canal treatment must not be time consuming if the student is properly trained on how to assess his own work

DIFFERENT IRRIGANT ACTIVATION TECHNIQUES IN REMOVING DENTIN DEBRIS: AN IN-VITRO STUDY

During endodontic treatment, the efficiency of irrigation depends on two criteria: the antimicrobial and dissolving properties of the irrigation solution and the delivery system used that dictates the flushing action of the irrigant and consequently enable it to reach complex areas. The purpose of this in-vitro study was to compare the cleaning efficiency of EDDY sonic activation with needle irrigation and passive ultrasonic activation regarding elimination of dentin debris. Forty single rooted extracted teeth were instrumented and then were split in bucco-lingual direction. A longitudinal groove was performed in the inner surface of one root half of each tooth. Grooves were filled with dentine debris mixed with 5.25 % NaOCl in order to simulate an uninstrumented canal extension. Root halves were reassembled and were randomly divided into three groups: G1 needle irrigation, G2 passive ultrasonic activation (Acteon Satelec, Merignac, France) and G3 sonic activation using EDDY system (VDW, Munich, Germany). Ten roots served as control. After irrigation protocols, root halves were disassembled and digital images of grooves were taken using a stereomicroscope (Olympus, Japan). Evaluation of the amount of the remaining dentin debris was performed using a scoring system. No statistically significant difference existed between negative control and passive ultrasonic activation and EDDY activation respectively. Both activation techniques performed equally in removing dentine debris and significantly better than needle irrigation. No significant difference was found between needle irrigation and positive control

MAINTAINING ROOT CANAL CURVATURES AFTER PREPARATION WITH DIFFERENT NICKEL-TITANIUM ROTARY SYSTEMS (A COMPARATIVE IN VITRO STUDY)

The ongoing advancement of materials and methods for root canal instrumentation is resulting in improved techniques with minimal variations to the canal morphology. One standard for assessment of the shaping quality of curved root canals is preparation-induced straightening of the canal. The aim of the study: To compare the effects of 2 Nickel-Titanium rotary systems, 2Shape (Micro-Mega, Besançon, France) and ProTaper Next (Dentsply,Sirona, Ballaigues, Switzerland), on maintaining the distobuccal canals curvature of extracted human maxillary molar teeth using periapical radiographs. Materials and methods: In this study a total of 26 distobuccal roots of upper maxillary molars were used and divided into 2 groups: Group 1 (n=13) root canals prepared with 2Shape system (TS1, TS2) (Micro-Mega, Besançon, France) and Group 2 (n=13) root canals prepared with ProTaper Next (X1, X2) (Dentsply,Sirona, Ballaigues, Switzerland). A buccolingual radiograph was taken for every sample before and after instrumentation in the same position, and the postoperative angle of curvature was measured with the Image J Software and the same principle of the method of Schneider. The post instrumentation curvature degree was subtracted from the pre instrumentation curvature degree and these results represented the degree of straightening. Result: P\u3c 0.05 was significant for ProTaper Next and 2Shape. 2Shape respected better the curvature angulations than ProTaper Next. Conclusion: Selection of the instruments has an important influence on the respect of the root canal curvature angulations

EVALUATION OF ROOT-END RESECTION WITH CONVENTIONAL AND ULTRASONIC METHODS: A SINGLE-BLIND, RANDOMIZED IN-VITRO STUDY

The root-end resection is considered critical endodontic surgical procedure. Three millimeters of the root tip is resected and root-end cavity with parallel walls and comparable depth is cut to receive a root-end filling. The literature discussed dentinal cracks after root canal instrumentation and/or root dentine cutting. The aim of the present study was to assess cracks at root ends after resection with conventional versus ultrasonic techniques. Material and Methodology: Thirty-two extracted human lower premolar teeth with single root were used. Their root canals were prepared and received gutta-percha. Sixteen roots Group 1 were resected using tungsten carbide fissure burs, while other sixteen teeth Group 2 were resected with ultrasonic tip, then all teeth had root end preparation with the ultrasonic coated retro trip. Both amount and categories of cracks on the resected surfaces were evaluated utilizing a dental operating microscope prior and following cavity preparation. Result: Cracking was statistically significant different among the two groups after resections or after cavity preparation

ERADICATION OF ENTEROCOCCUS FAECALIS IN CONVENTIONAL ENDODONTIC RETREATMENTS (A RANDOMIZED CLINICAL TRIAL)

Enterococcus faecalis is the most common bacteria isolated in conventional endodontic retreatments. Aim: To compare the impact of three irrigation modalities on the elimination of the isolated microbial strains of Enterococcus faecalis. Materials and Methods: Thirty patients requiring conventional endodontic retreatment for one of their mandibular premolars and tested positive for E. faecalis were chosen. Patients were randomly divided into three groups (n=10) according to the irrigation modality to be used; group I: syringe irrigation (NaOCl 2.625%), group II: NaOCl 2.625%+EndoActivator and group III: NaOCl 2.625%+diode laser. Before obturation, samples S2 were collected and PCR analysis was performed to identify the persistence of E. faecalis post- irrigation. Fisher exact test was used for differences in proportion between the three irrigation modalities. Analysis was achieved at the 0.05 significance level. Results: A significant statistical difference was revealed between group I and each of groups II and III whereas the statistical difference between groups II and III was not significant. Conclusion: Agitation with EndoActivator or activation with diode laser are necessary for a better eradication of E. faecalis in conventional endodontic retreatments