Aims:To compare the canal transportation, centering ability, and remaining dentin thickness of WaveOne and ProTaper systems using cone beam computed tomography.Subjects and Methods:Forty extracted human single-rooted premolars were used in the present study. Preinstrumentation scanning of all teeth was taken; canal curvatures were calculated, and the samples were randomly divided into two groups, with twenty samples in each group; one group was instrumented with WaveOne system and the other group with ProTaper rotary system. Postinstrumentation scans were performed, and the two scans were compared to determine canal transportation, centering ability, and remaining dentin thickness at 3 mm, 6 mm, and 9 mm from the root apex.Statistical Analysis Used:Student's unpaired t-test.Results:Using Student's unpaired t-test, results were as follows: for canal transportation, Group 1 showed significant difference at 3 mm and 6 mm and insignificant difference at 9 mm while Group 2 showed insignificant difference in all the three regions. For centering ability and remaining dentin thickness, Group 1 showed insignificant difference at 3 mm and 9 mm while significant difference at 6 mm was obtained. When comparison of remaining dentin thickness was done at three levels using two groups WaveOne and ProTaper, there was no significant difference between two groups.Conclusions:(1) WaveOne single reciprocation file system respected better canal anatomy better than ProTaper. (2) Individually, centering ability of WaveOne was better at 3 mm, 6 mm, and 9 mm levels. (3) However, ProTaper individually was better centered at 3 mm (apical third) and 9 mm (coronal 3rd) levels than 6 mm level (middle third).

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The objective of this work was to develop a short-term, clinically simulative, biofilm-based aging/storage model for lab testing of newer dental adhesives in order to predict their long-term performance. To do this we tested the hypothesis that 15 days of biofilm challenge with cariogenic bacterial species, Streptococcus mutans (SM) and Streptococcus sobrinus (SS), would produce similar or a greater reduction in microtensile bond strength (μTBS) of dental adhesives as compared to a standard 6 months of water storage (WS). Thirty-one molars were flattened to dentin, restored using Optibond-FL adhesive and Z-100 dental composite, sectioned and trimmed into four dumbbell-shaped specimens and randomly distributed according to aging conditions (n=31): A) Water storage for 6 months, B) Water storage for 5.5 months + S. mutans-biofilm challenge for 15 days, C) S. mutans-biofilm challenge for 15 days and D) S. sobrinus-biofilm challenge for 15 days. Specimens were gripped centrally with respect to the test axis with a nongluing passive gripping device. Microtensile bond strength testing was performed using a Zwick Material Testing Machine at a crosshead speed of 1 mm/min and failure modes were classified using light microscopy. Mixed model ANOVA and Weibull regression analysis revealed that the type of storage condition significantly affected the microtensile bond strength (p<0.0001). Mean microtensile bond strength observed within group A (49.69 ± 15.53MPa) was significantly higher than those in groups B (19.26 ± 6.26MPa), C (19.92 ± 5.86MPa) and D (23.58 ± 7.88MPa). Also, microtensile bond strength obtained with group D was significantly greater than that with groups B and C, while no difference was seen between vi the latter two groups. Chi-square statistical analysis indicated that specimens from groups B (74.2%), C (83.9%) and D (80.6%) were more likely to have cohesive failures in dentin than specimens from group A (54.8%). Within the limitations of the study, it can be concluded that 15 days of Streptococcus mutans-and Streptococcus sobrinus-based biofilm challenge produced more reduction in microtensile bond strength of dental adhesive than 6 months of water storage and appear to be a promising in vitro accelerated aging model.

Aim:This study aimed to compare the canal-centering ability, apical transportation, and remaining dentin thickness (RDT) of OneShape and WaveOne (WO) systems using cone-beam computed tomography.Objective:The objective of this study was to evaluate the efficiency of two rotary systems in maintaining original root canal anatomy.Materials and Methods:Forty extracted human single-rooted mandibular premolars were used in the present study. Preinstrumentation scans of all teeth were taken, canal curvatures were calculated, and the samples were randomly divided into two groups with twenty samples in each group: Group 1 – OneShape (OS) rotary system and Group 2 – WO reciprocation system. Postinstrumentation scans were performed using DICOM software and the two scans were compared to determine the canal-centering ability, canal transportation, and RDT at 1, 3, and 5 mm from the root apex.Results:Using Student's unpaired t-test, results were as follows: for canal-centering ability and RDT, Group 1 showed nonstatistically significant difference at 1 and 5 mm, while statistically significant difference (P < 0.05) at 3 mm was obtained. For canal transportation, Group 1 showed statistically significant difference (P < 0.05) at 1 and 3 mm and nonsignificant difference was obtained at 5 mm, but for Group 2, nonstatistically significant difference (P > 0.05) was obtained at 1, 3, and 5 mm. When comparing the RDT between both the groups, the difference was not statistically significant (P > 0.05).Conclusion:WO single reciprocation file has better canal-centering ability, maintains original canal curvature, causes lesser canal transportation, and preserves more dentine as compared to OS.

To establish a ratio of variable bone height (Infrazygomatic alveolar crest height) to constant bone height (Infraorbital zygomatic height) and, to estimate the relative sinus floor position from alveolar crest of maxillary first molar region of dentulous Indian males and females, using Digital panoramic radiographs. Panoramic radiographs of 74 patients were included in the study (37 male, 37 female) to measure maxillary posterior vertical bone height and their ratio in dentulous patients. Measurements were made from reference lines drawn from anatomic landmarks on soft digital versions of standardized panoramic radiographs using Kodak dental imaging software. Later the data were analyzed using normal test (Z-score). When the posterior maxillary bone height and their ratio were evaluated in Indian population, the vertical bone height (x, y, z) of males was more than the females. Ratio of Infrazygomatic-alveolar crest distance (y)/Infraorbital-zygomatic distance (x)-was 0.74 for Indian males and females. The relative sinus floor for Indian males was found to be 8.1 mm and that of Indian females to be 7.8 mm. The results are of significant value as "baseline" data, in serial studies where alveolar bone height for a single patient is compared at different times before and after tooth loss. The relative sinus floor position from alveolar crest can help in implant length selection. This study can be used as a diagnostic and predictive tool in implant treatment planning but further long-term evaluation is still required to prove the efficacy of this study.

Radio detection and ranging, that is, RADAR is a radio wave technique to determine the scope of the object, angle or speed. It is object detection technology. It is used to detect aircraft, ships, spacecraft, missiles, motor vehicles, weather formation and terrain. The proposed "Ultrasonic Radar System" uses an ultrasonic module that includes an ultrasonic transmitter and receiver as well as an AVR microcontroller ATmega128. It works by launching a short pulse at the ear audible frequency, after that microcontroller listens for echoes. The information about the distance to the object is given at the time elapsed during transmission to the echo reception. Here, the objective is to design an ultrasonic radar system by plotting its graph with the help of Matlab to identify the location of the object and its angle in the unauthorized area.

Aim:To investigate the effect of salivary contamination on the bond strength of two different seventh generation adhesive systems.Materials and Methods:Sixty caries-free human premolars with flat dentin surfaces were randomly divided into six groups of 10 teeth each and bonding was done using seventh-generation bonding agents Adper Easy One (3M ESPE) and Xeno V (Dentsply). Following the bonding procedure, resin composite was bonded to the surfaces using a plastic mould. The prepared specimen with composite cylinders attached were placed in 37°C distilled water for 24 h and then subjected to shear bond strength (SBS) with 0 h universal testing machine and the data were subjected to one-way analysis of variance and unpaired t-test.Results:Statistical significant difference between the Groups I, II and III in which Adper Easy One was used and similarly for Groups IV, V, and VI in which Xeno V was used. When an intergroup comparison was made using unpaired t-test Group II and Group V showed the nonsignificant difference.Conclusion:Salivary contamination significantly affects the SBS of both the seventh generation dentin bonding agents. However, 2-hydroxyethyl methacryate based adhesive has higher bond strength.