Aim:To evaluate the remaining dentin thickness of teeth after cleaning and shaping the root canal using three rotary instrumentation technique using cone-beam computed tomography (CBCT). Materials and methods:This in vitro study is being done with 30 premolar samples with 20' curvature. The study is divided into three groups a CBCT was taken to measure the shortest distance from the root canal outline to the closest adjacent root surface was measured at each level from the cementoenamel junction (CEJ) (1,3, 5 and 7 mm) before and after root canal instrumentation. The purpose of this study was to compare the effects of different instruments used to prepare curved root canals on the remaining cervical dentin thickness and total amount of dentin removed from root canals during instrumentation by using multi-slice CBCT. The remaining dentin thickness is very much necessary for the success rate of root canal treatment. However, this study helps to prove that a conservative preparation with a sound remaining dentin thickness is much more advisable.Result: It was observed that there was a significant difference at 1 and 3 mm (p < 0.05) and at 5 and 7 mm there was no significant difference ( p > 0.05). Mtwo has removed less amount dentin when compared to ProTaper Universal and ProTaper Next system at 1 and 3 mm.

INTRODUCTION: To compare the antibacterial effectiveness of three rotary file systems i.e., ProTaper Next, ProTaper Gold and XPendo Shaper in root canals of teeth with asymptomatic apical periodontitis by using the real-time polymerase chain reaction. MATERIALS AND METHODS: Root canals from single or multi-rooted teeth (straight canals) with necrotic pulps and asymptomatic apical periodontitis were instrumented using either ProTaper Next (n = 20), ProTaper Gold (n = 20) and XP-endo Shaper (n = 20) under irrigation with 3% sodium hypochlorite. Samples obtained before and after instrumentation were subjected to DNA extraction, amplification and quantitation of total amount of bacteria by using the real-time polymerase chain reaction. RESULTS: Samples were taken before preparation (S1) were positive for presence of bacteria, with mean numbers of 9.94 × 10 7 , 20.4 × 10 7 and 9.20 × 10 7 bacterial cells for the ProTaper Next, ProTaper Gold and XP-endo Shaper groups, respectively. After preparation (S2) with ProTaper Next, ProTaper Gold, and XP-endo Shaper, root canals still had bacteria with mean counts of 11.8 × 10 5 , 87.2 × 10 5 and 4.52 × 10 5 bacterial cells, respectively. Both XP-endo Shaper (99.50%) and ProTaper Next (98.81%) were effective in reducing total bacterial count, and there was no statistically significant difference between them (P > 0.05). XP-endo Shaper succeeded in reducing total bacterial count than ProTaper Gold (95.72%) and there exists statistically significant difference between them (P < 0.05). CONCLUSIONS: XP-endo Shaper was highly effective in reducing total bacterial count from root canals of teeth with asymptomatic apical periodontitis than ProTaper Gold. ProTaper Next also showed improved microbial reduction percentage as compared with ProTaper Gold.

Objective The objective of this study was to evaluate the irrigant penetration using iohexol dye with four irrigation techniques. Methodology Single-rooted premolars were recently extracted and preserved in physiological saline solution. All the samples were standardized to 16 mm. Standard endodontic access was prepared using endoaccess bur (Dentsply Maillefer, Switzerland). The initial patency was established using #10 k file (Mani, Utsunomiya, Tochigi, Japan) to the working length. The cleaning and shaping were performed using the file system ProFit S3 in the following sequence: P0 (orifice enlarger), PF1 (yellow), PF2 (red) #25, and PF3 (blue) #30. The samples were randomly allocated in concealed opaque envelopes into four groups. This was performed by a trained dentist. Fifteen samples were allocated to one group. The groups were divided as follows: Group A—conventional needle (CN), Group B—side-vented needle (SVN), Group C—manual dynamic agitation (MDA), and Group D—EndoActivator (EA). The radiopaque dye irrigant agitation/activation was performed by one operator to prevent operator bias. Following irrigation using the different techniques, digital radiographs were taken, and the measurement was taken from the apical foramen to the point where the dye had penetrated apically for each tooth and the data were entered into an Excel sheet for all the four groups. Results Comparing the four groups, there was a statistically significant difference among the four groups (p < 0.05), thus, favoring the alternate hypothesis. EA had resulted in better penetration of the irrigant compared with the other three groups (p < 0.05). Conclusion It was evident that irrigant penetration was best achieved with the use of an EA followed by MDA, SVNs, and then the CN when the preparation was done till size 30 (PF3 #30) using ProFit S3 rotary file system.

Aim: The aim of the study was to compare the canal transportation, centering ability, and dentin removal of Profit S3 (PS3), One Curve (OC), and ProTaper Gold (PTG) systems using cone-beam computed tomography (CBCT). Materials and Methods: Thirty extracted human single-rooted premolars were used in the present study. Preinstrumentation scanning of all the teeth in arch form was taken using CBCT. To increase standardization, crowns were removed and only teeth measuring 16 mm were included in the study. The samples were randomly divided into three groups, with ten samples in each group; Group I was instrumented with PS3, Group II was instrumented with OC, and Group III – PTG. Postinstrumentation scans were performed, and the two scans were compared to determine canal transportation, centering ability, and dentin removal at 3, 6, and 9 mm, from the apex. Statistical Analysis: One-way-ANOVA and the independent t -test were done for the pairwise comparison. The significance level was set at P = 0.05; statistical analysis was performed with SPSS statistics version 20.0 (SPSS Inc., Chicago, IL, USA). Results: The mean canal centering ratio and canal apical transportation for PS3, OC and PTG show no statistical difference ( P > 0.05). The mean value of dentin removal showed a statistically significant difference between the three groups ( P < 0.05). PS3 and OC rotary file showed less removal of dentin compared to PTG ( P < 0.00). Conclusion: It was evident that PS3, OC, and PTG had no statistically significant difference when analyzed based on canal transportation and canal centering ratio. However, there was a significant difference among the three groups comparing the removal of dentin. PS3 and OC rotary file showed less removal of dentin compared to PTG.

Objective To determine the effect of adhesive strategy (total etch or self-etch) of universal adhesives in non-carious cervical lesions. Data source A search was made in PubMed, Scopus, Cochrane, Web Of Science, Open Gray, Clinical Registries. Data selection Randomized Controlled Clinical Trials, studies on non-carious cervical lesions restored using Universal Adhesives, and studies in which universal adhesives have been used in total etch and self -etch strategies were included in this systematic review. Data extraction A total of 17 articles were included in the systematic review and 13 in the meta-analysis. Meta-analysis was conducted to assess the clinical performance of NCCLs in terms of retention, marginal adaptation, marginal discoloration, secondary caries and post-operative sensitivity at 18, 24, 36 month follow-up using USPHS as well as FDI criteria, separately. Data synthesis Overall there was no significant difference between total etch and self etch adhesive strategies for any of the five outcome measures using either the FDI or the USPHS criteria. p > 0.05, 95% CI, I2 value of 0%. A strongly suspected publication bias in the retention domain was seen at 18 month follow up under FDI criteria. Conclusion Most universal adhesives show acceptable clinical performance. There is no significant effect of the adhesive strategy of universal adhesives on their clinical performance according to the results of our meta-analysis.