Background: Apical extrusion of debris during instrumentation is detrimental to the patient. Aim: The aim of this study was to evaluate the apical extrusion of debris during root canal instrumentation using two single file rotary Ni-Ti systems. Materials and Methods: Thirty freshly extracted mandibular premolars with straight roots were sterilized and divided into two groups instrumented using: One Shape rotary Ni-Ti system with Endoflare orifice shaper (Group 1) and Neo-Niti rotary Ni-Ti system with C1 orifice shaper (Group 2). Preweighed Eppendorf tubes fitted for each tooth before instrumentation. During instrumentation, 1 mL of distilled water with a 30-gauge needle was used to irrigate after every instrument. Tips of the tooth were irrigated with 2 ml distilled water after removal from Eppendorf tubes. The total volume of irrigant in each group was the same 8 ml. All tubes were incubated at 68°C for 15 days and subsequently weighed. The difference between pre- and post-debris weights was calculated, and statistical analysis was performed using independent t-test and level of significance was set at 0.05. Results: The difference between pre- and post-weights was significantly greater for the One Shape system. Conclusions: The Neolix Niti single file was associated with less extrusion compared to One Shape single file system.

Background: Most often used intracanal medicament is calcium hydroxide (Ca(OH)₂). Removal of Ca(OH)₂before obturation is mandatory. Different irrigation solutions and devices were tested in the previous study for this purpose. Aim: The aim of this study was to evaluate the comparative efficacy of different irrigation techniques in removing intracanal medicament using cone-beam computed tomography (CBCT). Materials and Methods: Cleaning and shaping was carried out in 42 freshly extracted single-rooted mandibular first premolars using Protaper Rotary Files. Intracanal medicament (silicone oil-based Ca(OH)₂paste) was placed and left for 2 weeks in the root canal. Medicament was then removed by five different irrigation techniques: EndoActivator, EndoVac, ultrasonic irrigation with Endo-U-File, F-file, and Max-i-Probe needle. Changes in volume percentage were measured using CBCT and results were statistically analyzed using Levene's statistics and ANOVA. Results: Remnants of Ca(OH)₂were found in all experimental groups. No significant difference was detected among the groups. F-file showed maximum removal efficacy of approximately 48%. Conclusion: (1) There is no statistically significant difference between any irrigation technique for removal of oil-based Ca(OH)₂. (2) F-file demonstrated better results among all the other systems.

Objective: The objective of this study is to evaluate the fracture resistance of newer restorative materials that could serve as an alternate to crown coverage. Materials and Methods: Forty extracted human mandibular molar teeth were selected for this study and were divided into four groups (n = 10). All the teeth in the experimental groups (Group 2–4) were subjected to access cavity preparation with roughly 1.5 mm of tooth structure remaining throughout the circumference. Group 1: Intact teeth used as control. Group 2: Access cavities reinforced with biodentine. Group 3: Inner circumference of access cavities reinforced with polyethylene fiber and nano-hybrid composite. Group 4: Access cavities were reinforced with fiber reinforced composite. All the teeth were subjected to fracture resistance using universal testing machine. Results: The results of the study were evaluated statistically using one-way ANOVA and Tukey post hoc test. Group 2 demonstrated the least mean values of fracture resistance and was significantly different from the control and other experimental groups. Statistically significant difference among Groups 1, 3, and 4 was not found. Conclusion: Within the limitation of this in vitro study, it can be concluded that fiber reinforced composite and polyethylene fibers with nanohybrid composite could serve as an alternate to crown coverage.

Aim: Compare the measurement of working length with three different methods manual tactile sensation, digital radiography and Mutidetector computed tomography(MDCT). Materials and Method: 40 human premolar extracted for orthodontic purpose were selected. Teeth were store in sodium chloride (0.9%) during the study. Access cavity was prepared and canal patency was seen with no 10 file in each tooth. Manually no 15 K file was inserted from access cavity until the tip was visible at the foramen, a silicon stopper was adjusted to the corresponding buccal cusp tip and the root canal length was measured. After that in each tooth with no-15 K file inserted from access cavity with stop at tip of buccal cusp until tip appear at foramen and x-ray was taken with digital radiograph (RVG,Satelac) and canal length was measured. After that all teeth are mounted in wax block,MDCT scan was done and in the scan images of teeth, root canal length is measured from buccal cusp tip to root end. After taking measurement of working length with all three methods and the data was stastically analyzed with One Way Analysis of variance (ANOVA) followed by Turkey's Test. Results: ANOVA and turkeys test showed that there was no significant difference in the measurements by the three procedures (p>0.05). Conclusion: Working length measurement with MDCT scan and other two conventional methods does not show significant difference in measurement. Use of newer 3D imaging technique is useful in root canal treatment for measuring working length.

Objectives: To compare the relative axis modification and canal concentricity after glide path preparation with 20/0.02 hand K-file (NITIFLEX^®) and 20/0.04 rotary file (HyFlex™ CM) with subsequent instrumentation with 1.5 mm self-adjusting file (SAF). Materials and Methods: One hundred and twenty ISO 15, 0.02 taper, Endo Training Blocks (Dentsply Maillefer, Ballaigues, Switzerland) were acquired and randomly divided into following two groups (n = 60): group 1, establishing glide path till 20/0.02 hand K-file (NITIFLEX^®) followed by instrumentation with 1.5 mm SAF; and Group 2, establishing glide path till 20/0.04 rotary file (HyFlex™ CM) followed by instrumentation with 1.5 mm SAF. Pre- and post-instrumentation digital images were processed with MATLAB R 2013 software to identify the central axis, and then superimposed using digital imaging software (Picasa 3.0 software, Google Inc., California, USA) taking five landmarks as reference points. Student's t-test for pairwise comparisons was applied with the level of significance set at 0.05. Results: Training blocks instrumented with 20/0.04 rotary file and SAF were associated less deviation in canal axis (at all the five marked points), representing better canal concentricity compared to those, in which glide path was established by 20/0.02 hand K-files followed by SAF instrumentation. Conclusion: Canal geometry is better maintained after SAF instrumentation with a prior glide path established with 20/0.04 rotary file.

Background: Endodontically treated teeth often lack sufficient support for a permanent restoration. During post space preparation, it is important not to disturb the integrity of the apical seal. Aim: This study compared the effect of immediate versus delayed post space preparation on the apical seal using four different sealers. Materials and Methods: One hundred and thirty single rooted teeth were biomechanically prepared and obturated with single cone gutta-percha and 4 sealers: Endoflas FS, AH Plus, Gutta flow and MTA. Teeth were divided randomly into eight groups, post spaces were prepared using Gates Glidden drills immediately for group I, III, IV and VII. For groups II, IV, VI and VIII prepared after storage of the specimens in 100% humidity for one week. The samples were kept in methylene blue dye, centrifuged at 3000 rpm for 3 min sectioned and then measured under stereomicroscope for apical leakage. Statistical Analysis: The data was analysed using one way ANOVA and post hoc Tukey test. Results: All the specimens showed dye leakage, and a statistically significant difference was seen among all the groups (P > 0.05) except Gutta flow. Conclusion: Less leakage is seen when post space is prepared immediately.

Background: Root canal treatment has been a routine treatment option for carious exposure of the dental pulp. In the context of minimally invasive dentistry, direct pulp capping (DPC) procedure with a reliable biomaterial may be considered as an alternative provided the pulp status is favorable. Mineral trioxide aggregate (MTA), a bioactive cement with excellent sealing ability and biocompatibility is capable of regenerating relatively damaged pulp and formation of dentin bridge when used as DPC agent. Biodentine is comparatively a new biomaterial claimed to possess properties similar to MTA and is currently explored for vital pulp therapy procedures. Aim: The aim of the present study was to evaluate the clinical response of pulp-dentin complex after DPC with MTA and biodentine in carious teeth. Subjects and Methods: Twenty-four permanent molars with carious exposure having no signs and symptoms of irreversible pulpitis were selected and assigned to one of the two groups, Group I - MTA and Group II - biodentine. Patients were recalled at 3 weeks, 3 months, and 6 months for clinical and radiographic evaluation. Fisher's exact test was used along with Chi-square test for statistical analysis. Results: Over a period of 6 months, MTA and biodentine showed 91.7% and 83.3% success rate, respectively, based on the subjective symptoms, pulp sensibility tests, and radiographic appearance. Conclusion: MTA and biodentine may be used as DPC agents when the pulpal diagnosis is not more than reversible pulpitis.

Aims: The aim of this study was to quantify the debris extruded apically from teeth using rotary and reciprocation instrumentation systems. Subjects and Methods: Eighty extracted human mandibular premolars with single canals and similar lengths were instrumented using ProTaper Universal (40, 06; Dentsply Maillefer, Ballaigues, Switzerland), ProTaper Next (40, 06; Dentsply Maillefer, Ballaigues, Switzerland), WaveOne (40, 06; Dentsply Maillefer, Ballaigues, Switzerland), and Reciproc (R40; VDW GmbH, Munich, Germany). Debris extruded during instrumentation was collected into preweighed Eppendorf tubes, which were then stored in an incubator at 70°C for 5 days. The final weight of the Eppendorf tubes with the extruded debris was calculated after obtaining the mean of three consecutive weights obtained for each tube. Statistical Analysis Used: Statistical analysis was performed using SPSS version 16.0 software. The groups were compared using the Kruskal–Wallis test for all variables. Results: There was no statistically significant difference between the groups (P = 0.1114). However, the ProTaper Universal group produced more extrusion and ProTaper Next produced least debris extrusion among the instrument groups (P > 0.05). Conclusions: All instrumentation techniques were associated with extruded debris.

Aim: Dental tissues such as enamel, dentinoenamel junction (DEJ), dentin, and root dentin can react differently to demineralization and remineralization. The aim of this study was to evaluate the remineralization ability of sodium fluoride on the microhardness of enamel, dentin, and dentinoenamel junction. Materials and Methods: Ten extracted third molar teeth were sectioned mesiodistally to form control and test groups. For the test group, initial demineralization was done with acetic acid for 24 h followed by remineralization for 28 days by application of sodium fluoride (226 ppm) for 2 min twice a day. Vickers microhardness test was done to control and test groups at different sites after initial demineralization and on the 3^rd, 5^th, 7^th, 14^th, and 28^th day of remineralization. Statistical Analysis Used: Data were analyzed with one-way analysis of variance and post hoc test with a significance level of P < 0.001 with SPSS (21) software. Results: Microhardness values in the demineralization group were significantly lower than controls (P < 0.001). Evaluation of remineralization samples showed that microhardness similar to control values were achieved at the 3^rd day in root predentin and on the 5^th day in coronal dentin and coronal predentin. On the 7^th day, remineralization coronal predentin was significantly higher than the control (P < 0.001). On the 14^th day, DEJ axial zone and root dentin were similar to control and coronal dentin was significantly higher than the control (P < 0.001). Enamel was similar to control on the 28^th day. Microhardness of DEJ-cusp tip and DEJ-center of the fissure was significantly lower than control even at the 28^th day (P < 0.001). Conclusion: Long-term repeated application of sodium fluoride (226 ppm) can improve the microhardness of demineralized dental tissues on enamel, dentin, and DEJ-axial zone, except in the DEJ-cusp tip and DEJ-center of fissure.

Context and Aims: The purpose of this study was to compare and evaluate the shaping ability of ProTaper (PT) and Self-Adjusting File (SAF) system using cone-beam computed tomography (CBCT) to assess their performance in oval-shaped root canals. Materials and Methods: Sixty-two mandibular premolars with single oval canals were divided into two experimental groups (n = 31) according to the systems used: Group I – PT and Group II – SAF. Canals were evaluated before and after instrumentation using CBCT to assess centering ratio and canal transportation at three levels. Data were statistically analyzed using one-way analysis of variance, post hoc Tukey's test, and t-test. Results: The SAF showed better centering ability and lesser canal transportation than the PT only in the buccolingual plane at 6 and 9 mm levels. The shaping ability of the PT was best in the apical third in both the planes. The SAF had statistically significant better centering and lesser canal transportation in the buccolingual as compared to the mesiodistal plane at the middle and coronal levels. Conclusions: The SAF produced significantly less transportation and remained centered than the PT at the middle and coronal levels in the buccolingual plane of oval canals. In the mesiodistal plane, the performance of both the systems was parallel.

Aim: The aim of this study was to test the effect of new protocol of glide path preparation by 20/0.04 rotary file on apical extrusion of debris when instrumenting fine curved mesial canals in mandibular molars with Self-adjusting File (SAF) and compare it to a glide path prepared by 20/0.02 hand K-file and rotary OneShape (OS) and reciprocating WaveOne (WO) file instrumentation. Materials and Methods: Sixty mandibular molars with curved mesial roots were selected and randomly divided into three groups (n = 20) for instrumentation. In two groups, glide path was prepared using 20/0.02 K-file for instrumentation by OS (size 25/0.06 taper) and WO (size 25/0.08 taper) files; in the remaining group, 20/0.04 rotary file was used for glide path preparation and instrumented by SAF (1.5 mm). The debris extruded during instrumentation was collected in preweighed Eppendorf tubes and stored in an incubator at 70°C for 5 days. Tubes containing the dry extruded debris were then weighed. One-way analysis of variance (ANOVA) was applied to the weights obtained, followed by Tukey's post hoc test for multiple comparison. Results: The mean debris (g) extruded apically was 0.000651 ± 0.000291, 0.000823 ± 0.000319, and 0.000473 ± 0.000238 for Group 1 (20/0.02 + OS), Group 2 (20/0.02 + WO), and Group 3 (20/0.04 + SAF), respectively. The groups exhibited a significant difference (P < 0.01; ANOVA). Group 3 resulted in least debris extrusion compared to Groups 1 and 2 (P < 0.01; Tukey's post hoc test). Conclusion: Glide path prepared to size 20/0.04 and SAF 1.5 mm instrumentation produce less debris in curved mesial canals of mandibular molars, compared to glide path established by 20/0.02 and instrumentation by OS and WO files.

Aim: The aim of this study was to evaluate the fracture resistance of simulated immature teeth, when the root canals were completely filled either with mineral trioxide aggregate (MTA) or Biodentine, comparing with that of roots filled with apexification procedure. Materials and Methods: Sixty mandibular premolar teeth with single, straight canals decoronated at cementoenamel junction were divided into five groups (n = 12 each). Group 1 samples served as negative control and remaining four groups root samples were shaped and cleaned using ProTaper rotary files. To simulate immature roots, a #5 Peeso reamer was passed beyond the apex so that apices were enlarged to a diameter of 1.5 mm. Group 2 and 4 samples were filled with 5 mm of MTA or Biodentine apical plug and backfilling with gutta-percha using AH Plus sealer. Group 3 and 5 root samples were completely obturated with MTA and Biodentine, respectively. All the teeth were loaded vertically until fracture, using the universal testing machine. Statistical Analysis: Forces at which fracture of the roots occurred were subjected to statistical analysis using SPSS/PC version 2 software, and the results were analyzed with the one-way analysis of variance and Newman–Keuls multiple post hoc test. Results: Complete root canal obturation with MTA or Biodentine has shown significantly higher fracture resistance (P < 0.05) when compared to apexification with MTA or Biodentine. Conclusion: Obturation of the root canals with bioactive materials has shown highest fracture resistance when compared to apexification groups.

Aim: The purpose of this study was to evaluate the influence of chlorhexidine (CHX), grape seed extract (GSE), riboflavin/chitosan modification on microtensile bond strength (μTBS) of composite resin to dentin after polymerase chain reaction (PCR) thermocycling. Materials and Methods: Forty extracted human molars were used and a flat surface was then prepared by removing the occlusal one-third. The teeth were randomly assigned into four groups - Group I in which self-etch adhesive (Adper Easy One) was applied and Groups II, III, IV were pretreated with 2% CHX, 6.5% GSE, and 1% riboflavin/chitosan, respectively, before the application of self-etch adhesive. Composite build-ups were constructed, and PCR thermocycling (5000 cycles) was performed. The μTBS was evaluated using the universal testing machine. Data were analyzed using one-way analysis of variance and Tukey's test. Results: The mean μTBS values for Group I (control), Group II (CHX), Group III (GSE), and Group IV (riboflavin/chitosan modification) were 30.81, 43.15, 38.79, and 35.07 MPa, respectively. Conclusion: Pretreatment with CHX and GSE leads to a significant increase in μTBS of composite resin to dentin.

Aims: A study was done to evaluate the antimicrobial efficacy of sodium hypochlorite (NaOCl) and photoactivated disinfection (PAD) on Enterococcus faecalis. Settings and Design: Random sampling, in-vitro study. Subjects and Methods: Access opening and biomechanical preparation were performed on fifty freshly extracted mandibular second premolars. The specimens were sterilized; 15 μm of E. faecalis was inoculated into each canal and incubated at 36°C for 24 h. Later, specimens were randomly divided into two groups of fifty each and following procedures was carried out: (i) conventional irrigation with 2.25% NaOCl (ii) PAD using diode laser, and toluidine blue photosensitizer. Samples were collected from each canal using sterile paper points which were deposited in brain heart infusion broth, and microbiological evaluation was carried out. Statistical Analysis Used: Student's t-test was used to find the significant difference in the reduction of colony forming unit (CFU) between the groups. Results: The mean CFUs of the two groups showed statistically significant difference (P = 0.001). Improved antibacterial efficacy was seen with PAD group compared to conventional NAOCL irrigation. Conclusions: NaOCl alone was not effective in eliminating E. faecalis completely from the root canals. PAD compared to conventional irrigation showed the best results in removing E. faecalis from root canals.

Context: Direct pulp capping involves the placement of a biocompatible agent on pulp tissue that has been inadvertently exposed from traumatic injury or by iatrogenic means. Aim: To compare the human pulp response to calcium hydroxide and Biodentine as direct pulp-capping agents. Materials and Methods: Pulp exposures were performed on the pulpal floor of forty human permanent premolars. The exposure sites were dressed with either Dycal or Biodentine as pulp-capping materials. After 45 days, teeth were extracted and processed for histological examination. Statistical Analysis: The histological data were subjected to Wilcoxon rank-sum test. Results: The dentinal bridges in teeth that were capped with Biodentine were significantly thicker (P < 0.0001) and more continuous (P = 0.0001) with less pulpal inflammation (P = 0.0044) in comparison to Dycal. Conclusion: Based on the result of this study, Biodentine can be suggested as the material of choice for direct pulp capping procedure instead of Dycal. However, further long-term follow-up in vivo human studies using Biodentine on cariously exposed pulpal teeth are warranted to derive a definite conclusion.

Tooth surface loss (TSL) is a complex phenomenon characterized by the loss of hard tooth structure at various locations of the teeth, usually due to more than one factor. TSL due to abrasion can be significant in patients consuming coarse, abrasive diet. The present case reports an interesting incisal edge abrasion in a female patient, attributed to a particular dietary behavior of long-term consumption of sunflower seeds. All her family members and most of the people from her native place were also reported to have similar lesions by the patient. Larger epidemiological studies to assess the prevalence and severity of such abrasive lesions in geographic areas with this particular dietary habit need to be carried out so that people may be made aware and educated about alternative ways of eating sunflower seeds that will not cause any form of tooth wear.

The purpose of this study is to demonstrate the importance of knowledge of the internal anatomy of root canals for the success of endodontic treatment. Lack of knowledge of anatomic variations and their characteristics in different teeth has been pointed out as one of the main cause of endodontic therapy failure. Dental operating microscope plays a key role in the identification of canal and success of endodontic treatment. This case series describes the endodontic treatment of mandibular first molars with extra root canals, evaluate the occurrence of this extra canal, and discuss the importance of their identification and treatment.

Periapical diseases are induced as a result of the direct or indirect involvement of oral bacteria. The etiologic factor being the degenerating pulp tissue. A periapical lesion is formed within an area of apical periodontitis which cannot form by itself and is inflammatory in origin. If the microbial etiology of periapical lesions and in the root canal is removed by nonsurgical root canal therapy the lesions regress. Mere surgical removal of the periapical lesions without proper root canal disinfection and obturation will not result in the healing of periapical tissues. Nonsurgical treatment with triple antibiotic paste offers a high success rate in the healing of large periapical lesions. The present clinical cases show the nonsurgical endodontic management of large periapical pathosis using triple antibiotic paste and mineral trioxide aggregate.