Aim:  This study aims to evaluate and compare the antimicrobial effect of Photosensitized Nanoparticles, Diode Laser (DL), and Conventional and Sonic Irrigation Systems against Enterococcus faecalis in root canals – An in vitro Study. Materials and Methods:  The root canals of 104 extracted human single-rooted teeth were prepared, and E. faecalis was incubated in the root canals for 1 week. The teeth were randomly divided into four experimental groups and one control group (n = 20): No treatment was done, sodium hypochloride (NaOCl) group (n = 20): Canals irrigated with5 ml of 2.5% NaOCl for 60 s, NaOCl and Endoactivator group (n = 20): Canals irrigated with 5 ml of 2.5% NaOCl for 60 s followed by activation of NaOCl with Endoactivator for 30 s, NaOCl and 910 nm DL group (n = 20): (1 W 5 times for 5 s) canals irrigation with5 ml of 2.5% NaOCl for 60 s followed by Photodynamic Therapy (PDT) with 910 nm DL, silver nanoparticles (AgNPs)/Indocyanine green (ICG)/DL group (n = 20): DL modified PDT with 5 min of irrigation with 5 mL AgNPs (100 ppm)/ICG/910 nm DL (200 mW, 30 s). A reduction in colony count was assessed by counting colony-forming units by Digital Colony Counter. Results:  Significant reductions were noted in E. faecalis colony counts in all groups (P < 0.05). The greatest reduction in colony count (99.93%) was noted in the NaOCl and DL group followed by NaOCl and Endoactivator group; however, the differences in this respect between the AN/ICG/DL group and NaOCl group were not significant (P 0.05). Conclusions:  NaOCl and 910 nm DL were more successful in reducing the number of E. faecalis colony counts followed by NaOCl and Endoactivator group but it can also be concluded that PDT with ICG, an 910 nm DL, and AgNPs has the potential to be used as an adjunct for disinfection of the root canal system.

Aim:  The aim of this study is to evaluate the distance from the buccal cortical bone surface to the root apex in the anterior mandibular teeth using cone-beam computed tomography (CBCT) and to correlate it to various associated factors (tooth type, gender, and age). Materials and Methods:  CBCT images of mandibular anterior teeth from 120 patient records with a sample size of 360 teeth were analyzed. The distance from the buccal bone surface to root apex and 3 mm above the root apex in the sagittal view was reconstructed using the Romexis software version 3.2.1. Results:  Distances from the buccal cortical bone surface to the apices of the root and 3 mm from the apex of the root were greater at the mandibular canine region than the central and lateral incisor (P < 0.001). The buccal bone was significantly thicker corresponding to the apices of the teeth compared to the region 3 mm from the apex (P < 0.001) The mean distance value from the cortical buccal bone surface to the lateral incisor apex (4.03 mm) was significant more among females (P = 0.006). Furthermore, the measured distance at the root apex and 3 mm above the of the root apex of the mandibular anterior roots were significantly more in patients below the age of 40 years (P < 0.05). Conclusion:  The distance from the buccal bone's surface to the apex and 3 mm from the apex in the mandibular anterior region is significantly affected by the tooth type and patients' age. CBCT is a reliable tool for presurgical evaluation for both these parameters during endodontic surgeries and implant placement.

Aim:  To compare the sealing ability of polymethylmethacrylate (PMMA) bone cement, mineral trioxide aggregate (MTA), and Biodentine as root-end filling materials by assessing the degree of microleakage through confocal laser scanning microscopy. Materials and Methods:  Thirty extracted maxillary incisors were root canal treated using the rotary ProTaper system. Apical root resections followed by retrograde cavity preparation were done. The teeth were divided into three groups and filled with the 3 tested materials (PMMA bone cement, MTA, and Biodentine). Samples were coated with nail varnish, immersed in 0.5% aqueous solution of rhodamine B dye for 24 h, and rinsed with water to remove excess dye. Samples were horizontally sectioned at 1 mm intervals into three using a diamond disk and were labeled A, B, and C and considered first, second, and third, respectively, based on their distance from the apex. Each slice was divided into four equal parts and evaluated using a confocal laser scanning microscope. Dye penetration was scored based on the amount of microleakage. The data were analyzed using one-way analysis of variance. Results:  Intergroup comparison of the mean scores of dye penetration among the three materials showed that there is a statistical difference between PMMA bone cement, MTA, and Biodentine, in sections B and C (P ≤ 0.05). The three groups showed no statistical difference in dye penetration scores in section A. Conclusion:  The microleakage is least with PMMA bone cement followed by Biodentine and MTA. Microleakage was least in section C followed by sections B and A.

Aim:  The present study aimed to synthesize and characterize Nisin incorporated Alpha Tricalcium Phosphate (NTCP) and to evaluate nisin release from NTCP when used as a pulp capping agent. Methods:  Alpha TCP(aTCP) powder was synthesized by the wet chemical method. Nisin was incorporated into this prepared aTCP at various ratios and grouped as follows: Group 1 - 1% wt%; Group 2 -2.5wt%; Group 3-5%wt%; Group 4- 7.5%wt%; Group 5 -10%wt%; Group 6 -Nisin 100 mg; All these samples were characterized using Fourier Transmission Infrared Spectroscopy(FTIR) and Differential Scanning Calorimetry (DSC). For evaluation of nisin release from NTCP using HPLC, around fifteen freshly extracted non-carious human third molars were collected and mounted in gypsum blocks. A standard box-type class-I cavity (4.5x 4.5 mm) was prepared with the pulpal floor ending at deep dentin, The experimental materials were mixed with propylene glycol to prepare it as pulp capping material in paste form. Subsequently pulpal floor of all the cavities were lined with the respective materials. The entire samples were kept to set for 30 minutes in ambient temperature and subsequently immersed in water and stored in an incubator at 37oC. After 14 days of immersion, dentin lying directly below the sample was cut and powdered using mortar and pestle. The powdered dentin was then subjected to HPLC analysis. The peak time of nisin release from experimental groups was recorded. Results:  FTIR results revealed Group 5 with highly appreciable corresponding bends of amine N-H, C-H stretching and phosphate peaks at 1100 and 554 close to Control TCP samples. DSC analysis showed that TCP did not change from 30oC to 80oC and sample 1, 2, 3, and 4, did not show any denaturation point. Sample 5 showed denaturation point slightly above the denaturation temperature of nisin. On HPLC analysis, samples 4 and 5 showed higher peaks of nisin release and traces of nisin release from all the groups. Conclusion:  Within the limitations of this study, it can be concluded that NTCP can be synthesized successfully without any influence on the properties of each other material. 10% NTCP provides higher release into dentinal tubules when used as a pulp capping agent.

Aim:  The present in vitro study was designed to determine the effect of different access cavity designs on intracoronal bleaching of endodontically treated teeth with two different agents. Materials and Methods:  Fifty selected permanent maxillary central incisors were stained. Traditional and contracted access cavity designs and two types of bleaching agents, i.e., 35% carbamide peroxide and 35 percent hydrogen peroxide were used for the study. Color measurements were performed with a spectrophotometer: before staining (T1), after staining (T2), at 7 and 14 days (T3 and T4) post bleaching. The values were calculated and subjected to the statistical analysis. Results:  The results of our study showed that teeth in which traditional access cavity (TAC) was prepared had statistically significant better bleaching results with both 35% carbamide peroxide and 35% hydrogen peroxide than contracted access cavity design. Carbamide peroxide showed better results than hydrogen peroxide irrespective of the access cavity design, but difference was statistically nonsignificant. Conclusion:  The present study concluded that TAC design showed better results than contracted access with both carbamide peroxide and hydrogen peroxide. Whereas, when bleaching agents were compared 35% carbamide peroxide is better than 35% hydrogen peroxide irrespective of access cavity design used.

Objective:  This study aimed to compare the efficacy of diode laser, EndoActivator, passive ultrasonic irrigation (PUI), and manual dynamic activation (MDA) in the debridement of root canal isthmus using a stereomicroscope. Materials and Methods:  A total of 65 extracted mandibular first molars were selected for the study. The access cavity preparation was done and the working length was determined. All teeth were prepared using ProTaper rotary system up to F2. The samples were randomly divided into five groups (n = 13) used in the study. Group 1: Diode laser (n = 13): samples were irrigated using a diode laser having a wavelength of 980 nm. Group 2: EndoActivator (n = 13): the samples were irrigated using EndoActivator sonic device. Group 3: PUI (n = 13): samples were irrigated using an ultrasonic device. Group 4: MDA (n = 13): samples were irrigated manually by placing a master gutta-percha cone of F2 size. Group 5: Conventional needle irrigation (n = 13): no activation of irrigant. Following irrigant activation, the mesial roots were sectioned 4 mm from the apex and the isthmus cleanliness was observed under a stereomicroscope at ×20. Statistical analysis was done using ANOVA and post hoc Tukey's test. Results:  EndoActivator showed the least amount of debris when compared to diode laser, passive ultrasonic irrigant, and MDA. MDA showed more amount of debris at the isthmus level. Conclusion:  EndoActivator showed the least amount of debris at the isthmus level of mandibular molars when compared to diode laser, passive ultrasonic irrigant, and MDA.