A Comparative Evaluation of Push-Out Bond Strength of Six Different Root Canal Sealers: An In-Vitro Study.

BACKGROUND: Adhesiveness with radicular dentin is absent with gutta-percha, leading to microleakage and hence re-infection. Root canal sealer helps to achieve an adhesive interface between gutta-percha and root dentin thereby resisting the displacement forces during the functioning of teeth which is evaluated by the push-out test. The aim of this study is to compare the push-out bond strength and to assess the relative bond failure between dentin-sealer, sealer-main cone of (1) epoxy resin, (2) silicon, (3) mineral trioxide aggregate (MTA), (4) calcium hydroxide, (5) bioceramic, (6) zinc oxide eugenol containing root canal sealers. METHODOLOGY: Sixty human permanent lower premolars with one root were collected, disinfected, and decoronated at cemento-enamel junction. Instrumentation was done with a K3 40,0.06 Ni-Ti rotary file and obturated using the main cone and sealer. Based on the sealer utilized, six groups were created: Group 1: AH-Plus, Group 2: RoekoSeal, Group 3: MTA Fillapex, Group 4: Apexit, Group 5: Smart Paste Bio, and Group 6: Procosol. One slice each was obtained from the coronal, middle, and apicalsections of all the obturated canals. Push-out bond strength and failure modes were studied. Statistics involved analysis of variance (ANOVA) followed by the post hoc Tukey test. RESULTS: All three sections exhibited the highest strength for Smart Paste Bio sealer and the least was for RoekoSeal. With all the sealers, the apical section had the highest strength followed by the middle and coronal. CONCLUSION: The smart seal system was superior to all other sealers and displayed a good bond to dentin.

Assessment of Different File Systems for Working Time Based on Glide Path, Operating Kinetics, and the Fracture Resistance.

AIM: This study was done to assess the time to achieve the working distance based on the size of the glide path, operating kinetics, and the fracture resistance of different file systems. MATERIALS AND METHOD: One hundred and eighty mandibular premolars were divided into two groups of 90 each. Group I was subjected to continuous 360° rotary motion and group II to adaptive motion. Twisted File (TF) and Endostar E3 file methods were practiced in groups. The time (seconds) to achieving desired working length was recorded. Failures were classified as torsional failure or flexural failure. RESULTS: The time taken by glide path size 15 in group I was 5.90 ± 4.06 seconds and in group II was 6.12 ± 4.16 seconds. The time taken by glide path size 20 in group I was 5.86 ± 3.12 seconds and in group II was 4.22 ± 2.10 seconds, with 25 size the time taken in group I was 5.32 ± 2.48 seconds and in group II was 3.16 ± 3.14 seconds. The time taken by group I was less as compared to group II, and the difference was significant (p < 0.05). There was a significant difference in time taken with different number files in both groups (p < 0.05). The mean time taken reaching the working length for continuous rotation was less as compared to TF adaptive motion; however, the difference was nonsignificant (p > 0.05). CONCLUSION: We recorded higher instrument separation and deformation with the TF method and adaptive gesture. The TF system showed additional time to achieve the working distance as compared to the Endostar E3 system. CLINICAL SIGNIFICANCE: The TF system showed higher instrument separation and deformation, and it requires additional time to achieve the working distance compared to the Endostar E3 system. Hence, the Endostar E3 system is effective in achieving required clinical results.

Remineralization potential of fluoride, amorphous calcium phosphate-casein phosphopeptide, and combination of hydroxylapatite and fluoride on enamel lesions: An in vitro comparative evaluation.

AIM: The purpose of this study was to evaluate and compare remineralization potential of fluoride, amorphous calcium phosphate-casein phosphopeptide (ACP-CPP), and combination of hydroxyapatite (HAP) and fluoride on enamel lesions. MATERIALS AND METHODOLOGY: Ten intact caries-free human premolars were selected. The coronal portion of each tooth was sectioned into four parts to make four enamel blocks. The baseline surface microhardness (SMH) was measured for all the enamel specimens using Vickers microhardness testing machine. The artificial carious lesion was created by immersing the specimens in demineralizing solution for 3 consecutive days at 35° The SMH of each specimen was evaluated. All the four enamel sections of each tooth were subjected to various surface treatments, i.e., Group A - Fluoride varnish, Group B - ACP-CPP, Group C - Combination of HAP and fluoride (Clinpro), and Group D - Control group; no surface treatment. A carious progress test (pH cycle) was carried out which consisted of alternative demineralization (3 h) and remineralization using artificial saliva (21 h.) for 5 consecutive days. After pH cycling, SMH readings of each specimen were again assessed to evaluate remineralization potential of each surface treatment agent. RESULTS: Data obtained were statistically analyzed using one-way ANOVA followed by Tukey-Kramer multiple comparison test which was applied to detect significant differences between different surface treatments at different phases of studies. CONCLUSION: Fluoride varnish shows higher remineralization potential of early carious lesion compare to ACP-CPP and Clinpro.