Aim: The aim of this study is to evaluate the root canal transportation, centering ability, and instrumentation times with the ProTaper Gold (Dentsply Tulsa Dental, Tulsa, OK, USA), Reciproc (VDW, Munich, Germany), and ProTaper Universal (Dentsply Maillefer, Ballaigues, Switzerland) using cone-beam computed tomography (CBCT). Materials and Methods: Thirty mesial root canals of mandibular first molars with curvature angles of 35°–70° and radii of 2–6 mm were included in the study. Root canal instrumentation was performed up to F2 or R25. The instrumentation times were recorded. CBCT scanning was performed both pre- and post-instrumentation. Root canal transportation and the centering ratio were calculated for groups, and the data were analyzed using a one-way ANOVA and least significant difference post hoc tests for the instrumentation time, root canal transportation, and centering ratio at the 95% confidence level (P = 0.05). Results: At 3, 5, and 7 mm levels, there was no significant difference in the root canal transportation and centering ratio among the groups (P > 0.05). There were significant differences between the Reciproc and ProTaper Universal groups in the instrumentation times (P < 0.05). Conclusion: Root canal transportation and the centering ratio with the ProTaper Gold were similar to those obtained with the ProTaper Universal and Reciproc.

Aims: The aim of this study is to investigate the fracture load to failure and damage mode of the composite resin-veneered zirconia crowns preparing with two different zirconia surface treatments compared conventional porcelain-veneered zirconia crowns. Materials and Methods: Metallic molar-shape dies prepared with 10° convergence angle a 1.5 mm deep chamfer finish line were used. Two groups of composite-resin-veneered zirconia crowns were prepared using different surface treatment (Group A – sandblasting and Group B – glaze-on technique). Group C (conventional porcelain-veneered zirconia crowns) was served as control. Load to failure test was performed to evaluate the fracture resistance of the crowns using a universal testing machine. One-way ANOVA was used to evaluate the differences of mean values (P < 0.05) followed by Tukey's honest significance test multiple comparisons. Results: The mean fracture load to failure of Group A was 1078.45 ± 72.3, Group B was 1215.68 ± 100.76, and Group C (control) was 1203.67 ± 88.05. Modes of failure are 100% bulk fracture of the core through the veneering materials for Group B and C. However, Group A showed 40% delamination of composite veneering leaving zirconia coping exposed. Conclusions: Group B and C showed significant higher load to failure than Group A. Four specimens of Group A revealed the delamination of composite resin veneering.

Background: Canal transportation is a common sequel caused by rotary instruments. Aims: The purpose of the present study is to evaluate the degree of transportation after the use of Reciproc single-file instruments with or without glide path files. Methods: Thirty resin blocks with L-shaped canals were divided into three groups (n = 10). Group 1 - canals were prepared with Reciproc-25 file. Group 2 - glide path file-G1 was used before Reciproc. Group 3 - glide path files-G1 and G2 were used before Reciproc. Pre- and post-instrumentation images were superimposed under microscope, and resin removed from the inner and outer surfaces of the root canal was calculated throughout 10 points. Results: Statistical analysis was performed with Kruskal–Wallis test and post hoc Dunn test. For coronal and middle one-thirds, there was no significant difference among groups (P > 0.05). For apical section, transportation of Group 1 was significantly higher than other groups (P < 0.05). Conclusion: Using glide path files before Reciproc single-file system reduced the degree of apical canal transportation.

Aim: This study aims to evaluate the root canal transportation, centering ability, and instrumentation times after root canal preparation using reciprocating motion at 300 rotations per minute (rpm) and 600 rpm. Materials and Methods: Twenty mesial root canals of mandibular first molars with curvature angles of 35°–70° and radii of 2–6 mm were included in the study. Root canal instrumentation was performed using R25 according to the manufacturer's instructions at 300 rpm or 600 rpm (n = 10). Cone-beam computed tomography scanning was performed both pre- and post-instrumentation. Root canal transportation and the centering ratio were calculated for both the groups, and the data were analyzed using independent sample t-test for the instrumentation time, root canal transportation, and centering ratio at the 95% confidence level (P = 0.05). Results: At the three levels (3 mm, 5 mm, and 7 mm), there were no significant differences in centering ratio between the groups (P > 0.05). At 3 mm, 600 rpm resulted in more transportation than 300 rpm. However, there were no significant differences in the root canal transportation between the groups at 5 mm and 7 mm levels (P > 0.05). Conclusion: At the 3 mm level, 600 rpm resulted in more transportation than 300 rpm. However, centering ratio was similar at both 600 rpm and 300 rpm.

Aims: The aim of this study was to evaluate the specific chromatic alterations in tooth crowns induced by two different endodontic restorative materials. Settings and Design: This in vitro study was conducted at the Department of Conservative Dentistry, KMCT Dental College, Kozhikode, Kerala. Subjects and Methods: Forty-five freshly extracted, fully developed, single-rooted teeth were prepared and randomly assigned to two experimental groups (n = 15 each) and one negative control group (n = 15). Group 1 consists of white mineral trioxide aggregate (WMTA), Biodentine formed Group 2, and controls formed Group 3. Double-beam ultraviolet spectrophotometer equipment was used to assess the coronal discoloration as determined by CIE L*, a*, and b* and their corresponding total values. Results: At baseline, no significant difference was detected for CIE values between the groups. Group 1 showed a significant decrease in L*, a*, and b* values over time. The color change with WMTA led to clinically perceptible crown discoloration after 6 weeks which exceeded the perceptible threshold for the human eye, i.e., ΔE > 3.3. No changes were observed with Biodentine. Conclusions: Materials used in endodontics may stain teeth. WMTA induced clinically perceptible crown discoloration, whereas Biodentine demonstrated color stability.

Aim: The purpose of this in vitro study was to evaluate the vertical force required to fracture mandibular incisor teeth, obturated using gutta-percha with three different sealers. Materials and Methods: Seventy-five extracted mandibular incisors with intact and fully formed apices, exhibiting single root and canal were acquired. The teeth were decoronated obtaining a root segments of 15 mm and were divided into five groups (n = 15). Group 1: left uninstrumented and unfilled (negative control). For groups 2–5, samples were instrumented using Protaper NEXT (X1 and X2). Group 2: left unobturated (positive control). Groups 3–5 were obturated using lateral compaction by gutta-percha and three sealers (AH Plus^®, Apexit^®, and EndoSequence^® BioCeramic™). All the samples were prepared for fracture testing and vertical load was applied till fracture. Statistical analysis was performed using ANOVA and Tukey's post hoc test, for the data recorded of the force required in Newton (N). Results: The load required to fracture exhibited a significant difference. The intergroup analysis revealed, samples obturated using bioceramic sealer exhibited higher fracture resistance (P < 0.01). Conclusion: The use of gutta-percha and a root canal sealer reinforces the root dentin, leading to increased fracture resistance against vertical forces. Bioceramic sealer group in them exhibited better results.

Aim: This study was undertaken to evaluate the efficacy of smear layer removal and nanostructural and chemical changes caused by chitosan and ethylenediaminetetraacetic acid (EDTA) on tooth surface using atomic force microscopic analysis and energy-dispersive X-ray (EDX) analysis. Methodology: Forty single-rooted premolars were decoronated to a standard length of 15 mm and enlarged to Protaper F3 with irrigation of 1 mL 1% NaOCl and deionized water. Specimens were then divided into 4 groups with 10 samples each and subjected to final rinse with 17% EDTA solution, 0.2% and 0.5% chitosan solution for 1 min. Samples were sectioned into 2 halves. One half of sample from each group were subjected to EDX analysis to check the calcium/phosphate (Ca/P) ratio. The second half of sample from each group subjected to atomic force microscopy (AFM) analysis to study the smear layer removal and nanostructural changes. Statistical analysis was done using ANOVA and Chi-square test. Results: The AFM images showed no difference in the elimination of smear layer. The quantitative analysis using AFM showed EDTA group had significantly higher surface alteration than chitosan. EDX analysis showed that the Ca/P ratio of root dentine in EDTA group is significantly lower than chitosan group. Conclusion: Chitosan is an effective chelating agent with less alteration in radicular dentine.

Introduction: The aim of the present study was to comparatively evaluate the accuracy of iRoot, iPex II, and Propex pixi apex locator using histological sections as the gold standard. Materials and Methods: Thirty patients indicated for extraction of single-rooted permanent teeth with single canal system were selected. Working lengths (WLs) of teeth were determined using iRoot, iPex II, and Propex pixi. Teeth were then extracted, and the files were reintroduced to the anatomic apex to measure anatomic canal length (ACL) and fixed at the ACL using flowable composite. The apical 4 mm of the roots were longitudinally shaved away to visualize the canal under a stereomicroscope at ×24 magnification. Digital photographs were evaluated to measure the distance between the major diameter and minor diameter. Thus, the WL, that is, the minor diameter length (MDL) was ascertained. Results: Measurements of mean WLs within ±0.5 mm of minor diameter were 90% acceptable for iRoot, 86.66% for iPex II, and 80% for Propex pixi when compared with mean MDL as obtained from the histological sections. Conclusions: All apex locators have been shown to produce acceptable level of accuracy which clearly indicates their reliability in determining the WL.

Background: The technique of alternating rotation has been used with NiTi rotary instruments to increase the resistance to fracture compared with conventional continuous rotation. However, it is still not clear what type of instrumentation could provide better results in the preservation of the original canal anatomy. Aim: The aim of this study is to determine the influence of the type of rotation on canal transportation and centering ability using cone-beam computed tomography (CBCT) imaging. Materials and Methods: In total, 50 mesial canals of mandibular molars with curvatures between 30° and 60° were divided into two experimental groups (n = 25 each) according to the type of movement employed with the ProTaper Next (PTN) instruments: Group A (alternating rotation) and Group B (continuous rotation). Canals were scanned before and after instrumentation using a CBCT scanner to evaluate root canal transportation and the centering ratio at 3, 5, and 7 mm from the apex. Data were analyzed statistically using Student's t-test; the significance level was set at P < 0.05. Results: There was no significant difference between the groups in canal transportation or the centering ratio at any of the three studied cross sections (3, 5, and 7 mm). Conclusions: PTN instruments promoted minimal apical transportation and remained relatively centered within the root canal, with no significant difference between alternating and continuous rotation.

Background and Objectives: EQUIA^TM is a new gastrointestinal (GI) system with high compressive strength, surface microhardness (MH), and fluoride release potential. This in vitro study aimed to assess the effect of aging and type of protective coating on the MH of EQUIA^TM GI cement. Materials and Methods: A total of 30 disc-shaped specimens measuring 9 mm in diameter and 2 mm in thickness were fabricated of EQUIA^TM GI and divided into three groups of G-Coat nanofilled coating (a), no coating (b) and margin bond (c). The Vickers MH value of specimens was measured before (baseline) and at 3 and 6 months after water storage. Data were analyzed using repeated measures ANOVA. Results: Group B had significantly higher MH than the other two groups at baseline. Both G-Coat and margin bond increased the surface MH of GI at 3 and 6 months. The MH values of G-Coat and margin bond groups did not significantly increase or decrease between 3 and 6 months. Conclusion: The increase in MH was greater in the G-Coat compared to the margin bond group in the long-term. Clinically, margin bond may be a suitable alternative when G-Coat is not available.

Aim: The purpose of this clinical study was to compare and clinically, to evaluate the accuracy of six apex locators with intra oral periapical (IOPA) radiograph in multirooted teeth. Materials and Methods: A total of 90 multirooted teeth (maxillary and mandibular molars) with irreversible, infected or necrotic pulp tissue and completely formed roots were included in this study and were divided randomly into six groups (Root ZX II, Raypex 6, I-Root, Romiapex A-15, Sybron Endo Mini and Root ZX mini). The working length was determined using six different apex locators, and the accuracy of the apex locators was compared with IOPA radiographs, to be categorized as accurate, short, and long or beyond. Results: A total of 270 canals were evaluated, of which 233 (86.3%) canals exhibited acceptable working length, 28 (10.4%) canals exhibited short working length, and only 9 (3.3%) canals exhibited working length beyond the apex. There were a statistically significant results in all the groups (P < 0.05) and the comparison between the groups was statistically insignificant. Conclusion: The repeatability with that of apex locators is of great advantage, but the information gained from the radiographs cannot be obtained by any other means. Therefore, it is recommended that radiograph and apex locators are the best combinations in accurately determining the working length and the successful endodontics.

Introduction: Dentin hypersensitivity (DH) is a sudden short sharp pain best explained by hydrodynamic theory. Several agents are available throughout the market that can treat DH either by blocking the nerves that helps in conducting pain or by blocking the open dentinal tubules. The aim of the present study was to compare the tubule occluding efficacy of four different desensitizing dentifrices under scanning electron microscope (SEM). Materials and Methods: Sixty-two dentin blocks measuring 5 mm × 5 mm × 3 mm were obtained from extracted human molar teeth and were randomly divided into five groups: Group 1 – no treatment (control, n = 2); Group 2 – Pepsodent Pro-sensitive relief and repair (n = 15); Group 3 – Sensodyne repair and protect (n = 15); Group 4 – Remin Pro (n = 15); Group 5 – Test toothpaste containing 15% nano-hydroxyapatite (n-HA) crystals (n = 15). The specimens were brushed for 2 min/day for 14 days and stored in artificial saliva. After final brushing, specimens were gold sputtered and viewed under SEM at ×2000 magnification. Results obtained were statistically analyzed using nonparametric Kruskal–Wallis test and least significant difference post hoc test. Results: All test groups showed significant increase in dentin tubule occlusion as compared to control group. The highest percentage of tubules occluded was shown by Group 4 and Group 5 which was significantly different from other groups (P ≤ 0.05), and there was no significant difference in tubule occlusion among them. Conclusion: Newer desensitizing dentifrices containing 15% n-HA and Remin Pro can provide effective tubule occlusion and thereby reduce the pain and discomfort caused by DH.

The purpose of these case reports is to emphasize the importance of knowledge regarding the root canal morphology and current diagnostic aids one should have as both of these important factors going to affect the prognosis of the endodontic treatment. These two case reports describe the maxillary and mandibular first molars with multiple canals. After clinical and radiographic diagnosis, additional help of cone-beam computed tomography (CBCT) of mandibular molar has been taken to evaluate the morphology and canal pattern; while maxillary molar was evaluated using CBCT scan to evaluate the canal configuration and obturation. In CBCT evaluation, the mandibular molar was diagnosed with six separated canals with three mesial and three distal canals and with radix paramolaris and radix entomolaris. The maxillary molar had five canals with three mesiobuccal (MB) canals. Both molars were instrumented with conventional hand and rotary file systems and obturated by conventional lateral compaction method. The axial images from CBCT show Vertucci Type VIII canal pattern in both roots of first mandibular molars and in MB root of maxillary first molar Sert and Bayirli Type XVIII canal configuration and no accessory canal in distobuccal and palatal root. With the recent innovations in diagnostic and operating aids, we can come across many variations in the root canal morphology of both mandibular and maxillary teeth, especially multi-rooted one (i.e., molars), and the knowledge of which leads to successful endodontic treatment with an excellent prognosis.

Ferric sulfate (FS) has been commonly used as a local hemostatic agent for more than three decades in dentistry. Even though the hemostatic mechanism of FS is questioned, it seems that agglutination of blood proteins occurs due to the reaction of blood with ferric and sulfate ions in acidic pH. FS has gained widespread importance as a pulpotomy medicament in contemporary dentistry; nevertheless, it has several applications in different fields of dentistry which was paid little attention. Hence, the purpose of this paper is to review the various applications of FS in dentistry, along with restorative dentistry and endodontics.

The knowledge of variations in root canal morphology is essential for a successful endodontic outcome. Contralateral mandibular molar with six root canals is a rare entity. Root canal treatment of mandibular molars with aberrant canal configuration can be diagnostically and technically challenging. While dealing with variant mandibular molars, mishaps may happen. This case report describes variations in contralateral mandibular molars and also an endodontic mishap while managing them.