Application of a new system for classifying root canal morphology in undergraduate teaching and clinical practice: a national survey in Malaysia.

AIM: To evaluate and compare the feedback of final year undergraduate dental students in eight Malaysian dental schools on the application of a new system for classifying root canal morphology in teaching and clinical practice. METHODS: One PowerPoint presentation describing two classification systems for root canal morphology (Oral Surgery Oral Medicine Oral Pathology, 1974 38, 456 and its supplemental configurations, International Endodontic Journal 2017, 50, 761) was delivered to final year undergraduate dental students in eight dental schools in Malaysia by two presenters (each presented to four schools). To examine students' feedback on the utility of each system, printed questionnaires consisting of six questions (five multiple choice questions and one open-ended question) were distributed and collected after the lecture. The questionnaire was designed to compare the classification systems in terms of accuracy, practicability, understanding of root canal morphology and recommendation for use in pre-clinical and clinical courses. The exact test was used for statistical analysis, with the level of significance set at 0.05 (P = 0.05). RESULTS: A total of 382 (out of 447) students participated giving a response rate of 86%. More than 90% of students reported that the new system was more accurate and more practical compared with the Vertucci system (P < 0.001). Overall, 97% of students reported the new system helped their understanding of root and canal morphology compared with the Vertucci classification (P < 0.001). Over 97% of students recommended the use of the new system in teaching, pre-clinical courses and clinical practice (P < 0.001). Except for two schools, no significant difference was detected between the responses of students for all questions at the different schools (P > 0.05). The students' responses for all questions were almost similar for both presenters (P > 0.05). CONCLUSIONS: The new system of International Endodontic Journal 2017, 50, 761 for classifying root and canal morphology was favoured by final year undergraduate dental students in Malaysia. The new system has the potential to be included in the undergraduate endodontic curriculum for teaching courses related to root and canal morphology.

Microleakage of Different Thickness of Restorative Materials Used in Endodontically Treated Teeth by Dye Penetration

@#This study aimedto evaluate the coronal microleakage of different thickness of different restorative materials (glass ionomer cement (GIC, GC Gold Label 2), composite restoration (SDR, Dentsply Sirona) and (Filtek Z350 XT, 3M ESPE)) used as final restoration in endodontically treated teeth. 72 sound maxillary incisors were used. Following instrumentation, all canals were obturated with gutta-percha (Dentsply Maillefer) and Roth sealer (Roth International Ltd). After 2mm of gutta-percha removal below cemento-enamel junction, the crown was cut until length of 6mm from the gutta-percha to the incisal edge was achieved. The teeth were divided into four experimental groups (n=18) and access restorations were placed in different thickness combinations. Group 1 (G1): 2mm SDR + 4mm Filtek; Group 2 (G2): 4mm SDR + 2mm Filtek; Group 3 (G3): 2mm GIC + 2mm SDR + 2mm Filtek; Group 4 G4): 6mm SDR. All samples were thermocycled (500 thermal cycles between 5o and 55oC and dwell time of 30s), coated with nail varnish leaving 1mm margin around the filling material, immersed in 2% Rhodamine B solution and sectioned longitudinally. The dye penetration was observed under a stereomicroscope (Olympus SZX7) with 1.25x magnification. The data were analysed using Kolmogorov-Smirnov test, ANOVA test and post-hoc Tukey’s HSD test.There was significant difference of microleakage among all groups. G1 showed least microleakage but with no significant difference between G1 and G3 (p=0.513) and G1 and G4 (p=0.477). G2 showed significant microleakage compared to G1, G3 and G4 (p<0.05). In conclusion, sandwich technique between SDR and Filtek reduces microleakage in which the combination of 2mm SDR with 4mm Filtek in G1 had the least microleakage but with additional 2mm of GIC in G3 further reduces the microleakage.