Relation between Apical Seal and Apical Preparation Diameter: An In Vitro Study.

BACKGROUND: The current recommendations for the apical preparation diameter, one of the most important mechanical imperatives in the apical third preparation, are to preserve the apical foramen in its original position along with its narrowest diameter to avoid any complication such as tearing, zipping, or transport of the foramen. The aim of our study was to see the correlation between apical seal and apical preparation diameter. MATERIALS AND METHODS: In total, 90 extracted maxillary incisors were randomly allocated into three groups of 30 teeth each according to the apical preparation size: Group 1: finishing file F1 corresponding to size 20 reached the working length, Group 2: prepared up to size 30 corresponding to finishing file F3, and Group 3: prepared up to size 50 corresponding to finishing file F5. After the filling of the root canals, the teeth were isolated and immersed in a dye solution, then cut longitudinally, photographed, and the dye penetration were calculated using a computer software. RESULTS: Comparison of the three different apical preparation sizes showed no statistically significant differences regarding the apical microleakage. CONCLUSION: The most important value of the dye penetration was observed in the group with the largest apical diameter.

Assessment of Enamel Surface Microhardness with different Fluoride Varnishes-An In Vitro Study.

AIM: This study aimed to assess the microhardness of the enamel surface after fluoride varnish application. MATERIALS AND METHODS: Thymol of 0.1% in distilled water was used to store the collected healthy sixty teeth. The samples were divided into three groups randomly as per the different applica -tion of fluoride varnish. Group A: Fluor protector varnish (FIV) application, group B: Duraphat varnish application and group C: Bifluorid 10 varnish application. The present study followed the pH cycling protocol. Microhardness tester was used to test the microhardness of enamel surface and was expressed as micro-hardness measurements of Vickers hardness number (VHN) which was performed at baseline, on the 3rd day andon 7th day. RESULTS: At baseline, group A samples mean SMH value was 230.64 ± 12.32 which was slightly more than group B with 229.45 ± 10.22 and group C with 230.10 ± 11.45. There was no significant difference showed with the analysis of variance between the groups. On the 3rd day, there was a slight increase in the mean SMH in group A with 235.39 ± 6.44 and no significant difference between the groups was seen statistically. On the 7th day, the group A showed high SMH value of 262.20 ± 4.89 compared to other groups which didn't show a significantly high statistical difference. CONCLUSION: On conclusion, post-application of fluorprotector varnish showed higher enamel surface microhardness compared to Duraphat and Bifluorid 10 varnishes. CLINICAL SIGNIFICANCE: In young children, fluoride varnishes are effectively used as a noninvasive, anti-caries agent in the treatment of initial caries. Therefore, in routine dental practice, the knowledge about different fluoride varnishes is of importance.

Evaluation of Intracanal Calcium Hydroxide Removal with Different Techniques: A Scanning Electron Microscope Study.

AIM: This study aimed to evaluate the efficacy of Intracanal calcium hydroxide removal with different techniques. MATERIALS AND METHODS: Seventy-five freshly extracted, non-carious, single canalled lower first premolars, having anatomic characteristics similar to each other, extracted for the orthodontic purpose were collected. After the root canal preparation, Calcium hydroxide was placed into the working length using lentulo spiral instrument till the medicament was visible at the apex. The specimens were segregated into three groups; Group 1: Rotary Files, Group 2: EndoVac system and Group 3: Ultrasonics. The evaluation was done with SEM in the coronal and apical third of the roots with a magnification of 1000x. The statistical analysis was done using statistical packages for social sciences (SPSS) software, version 20.0 for Windows (SPSS Inc., Chicago, IL). A p-value of less than 0.05 was considered significant statistically. RESULTS: Maximum removal of Ca(OH)2 was analyzed in the EndoVac system (2.90 ± 0.12) followed by the rotary files (1.76 ± 0.26) and least was seen with Ultrasonics (1.32 ± 0.14). The p-value of 0.001 was seen between the coronal and apical third with the EndoVac system which is statistically significant. The significant difference statistically was observed between Rotary Files vs. Ultrasonics at apical third and with the EndoVac system vs. Ultrasonics at coronal third as well as at the apical third with p-value 0.001. CONCLUSION: It can be concluded that the EndoVac technique was effective in removing Ca(OH)2 medicament from the coronal and apical third of the root canal significantly. CLINICAL SIGNIFICANCE: Calcium hydroxide removal before the obturation was of priority as the Ca(OH)2 remnants have a negative impact of the ability for sealing the obturation material. Therefore, having a complete knowledge regarding the effective technique is much important.