Evaluation of the Apical Seal of Mineral Trioxide Aggregate in the Absence and Presence of Smear Layer.

AIM: The aim of this study was to in vitro evaluate the apical sealability of mineral trioxide aggregate (MTA) when used as an orthograde root filling material, and to evaluate whether smear layer removal has any influence on the apical seal of this material. MATERIALS AND METHODS: Forty single-rooted human mandibular premolars were selected in this in vitro study. The selected teeth were randomly divided into two equal groups (n = 20) based on the irrigation type. Group 1 was irrigated using distilled water to keep the smear layer intact, and group 2 was irrigated using NaOCl 5.25% and ethylenediaminetetraacetic acid (EDTA) 17% to remove the smear layer. All teeth were instrumented using a step-back technique and obturated using white MTA. Microleakage of 0.2% rhodamine B solution at the tooth-material interface was evaluated to assess the apical seal of MTA. The data were analyzed statistically using Mann-Whitney test U-test (p = 0.05). RESULTS: When the smear layer was present, MTA revealed less leakage compared to the group of MTA without smear layer with statistically significant difference (p <0.05). CONCLUSION: The apical seal produced by MTA when smear layer is left intact was better than the apical seal of MTA when smear layer is removed.It can be stated that MTA is a promising root canal filling material with good sealing ability in the presence of a smear layer. CLINICAL SIGNIFICANCE: Using white MTA material for the obturation of root canals is a useful procedure. It could be done without complexity in irrigation during root canal treatment and cause no discoloration to the teeth.

Modalities of using endodontic nickel-titanium rotary instruments and factors influencing their implementation in dental practice.

BACKGROUND: To establish the extent of using nickel titanium rotary instruments (NiTi-RIs), to identify reasons for using / not using NiTi-RIs, to explore usage modalities and to identify factors and measures that can increase implementation of NiTi-RIs in general dental practice. METHODS: Two pilot questionnaires were conducted on academic staff members at College of Dentistry, Taibah University, general dentists (GDs) and endodontists to finalise the questionnaire. A sample size was calculated considering the expected and minimum accepted response rates (60 and 48%, respectively) and a 99.9% Confidence Level. The online-questionnaire was sent to 600 GDs and all endodontists (175) working in Saudi Arabia. A reminder was emailed after 10 weeks to encourage non-respondents to complete the questionnaire. Responses, were collected and converted into numerical data which were analysed using the Chi-square test (p = 0.05). RESULTS: Significantly most respondents (71.9%) used NiTi-RIs (p < 0.001); with more endodontists (96.9%) than GDs (60%). Most users (62.5%) had been using NiTi-RIs for More than 3 years (p < 0001). The trend of using NiTi-RIs increased as participants' experience and the number of root-canal treatments performed per week increased (p = 0.021). While most respondents (45.3%) used NiTi-RIs because of faster root-canal preparation, the majority of non-users (85.3%) didn't do so because of high cost. The highest proportion (43.3%) reported better undergraduate education as the most important factor that can significantly increase NiTi-RIs usage. The majority (91.8%) prepared glide-path before using NiTi-RIs; especially with stainless steel hand-files (63.3%). CONCLUSIONS: NiTi-RIs are relatively well adopted in Saudi dental practice. However, better education, especially during undergraduate training and lower cost can increase their usage. Overall, clinicians showed good awareness of NiTi-RIs usage aspects which reflected on usage modalities.