Dual- or single rinse? The tubular sealer penetration of endodontic chelating agents.

INTRODUCTION: In this study, we aimed to compare the effectiveness of various chelating agents, ethilenediaminetetraacetic acid (EDTA), citric acid (CA), and etidronic acid (HEDP) mixed in two different forms, in removing the smear layer and promoting the penetration of an endodontic sealer into the dentinal tubules of extracted single-rooted teeth. METHODS: The study used 75 teeth divided into five groups: 17% EDTA, 10% CA, 9% HEDP + NaOCl, 9% HEDP + distilled water (DW), and a control (DW) group. Scanning electron microscopy was used to assess smear layer removal and confocal laser microscopy was used to evaluate tubular sealer penetration at different depths from the apical tip. RESULTS: Sealer penetration was highest with 17% EDTA and 10% CA as compared with the other agents (p<0.001). At the cervical third, the sealer penetration for EDTA, HEDP + NaOCl, and HEDP + DW groups were significantly different than those in DW (p = 0.020). For the middle third, EDTA, CA, and HEDP + NaOCl groups were significantly higher than those of the DW group (p<0.001). Cervical-level values were significantly higher than apical-level values for HEDP + NaOCl, HEDP + DW, and DW (p<0.001). Smear layer removal was lower with 9% HEDP + DW than with 17% EDTA and 10% CA at all depths (p<0.001). A significancy in smear layer removal was observed between 10% CA and control (p = 0.015) in middle depth. CONCLUSION: Within the limitations of this study, highest values were seen in EDTA and CA in terms of sealer penetration and smear layer removal. In the light of these findings, the use of strong chelating agents highlights better clinical efficiency than dual-rinse or single HEDP irrigation.

Surface roughness and cyclic fatigue resistance of a novel shaping system: An in-vitro study.

Recently developed Nickel-Titanium (NiTi) instruments with practical changes have resulted in safer instrumentation. In addition, topographical features on the file surface are a contributing factor to clinical durability. Therefore, this study aimed to investigate both the cyclic fatigue resistance and the roughness change of MTwo and Rotate instruments (VDW, Munich, Germany). Each instrument (n = 6/each group) was scanned with an atomic force microscopy prior to and after instrumentation. In addition, cyclic fatigue testing was conducted for each instrument (n = 11/each group) with stainless-steel blocks, including 45°-60°-90° degrees of curvature milled to the instruments' size. The roughness parameters increased for both systems after instrumentation (p<0.05). Both systems presented an increased roughness following instrumentation (p<0.05). The cyclic fatigue resistance was lowest at 90° for both systems (p<0.05), whereas the Rotate files presented a higher resistance than that of the Mtwo files (p<0.05). Compared to the Mtwo files, Rotate files presented better resistance, while the resistance decreased as the curvature increased.

Evaluation of mandibular cortical and trabecular radiomorphometry in familial Mediterranean fever patients.

OBJECTIVE: The objective of this retrospective study was to evaluate the mandibular cortical and trabecular morphology and microarchitecture of patients with familial Mediterranean fever (FMF) and compare them to those of healthy individuals by examining radiomorphometric indices on panoramic radiographs. STUDY DESIGN: We examined a group of 56 FMF patients aged 5 to 71 years and an age- and sex-matched control group of individuals with no systemic diseases. We classified the FMF and control groups according to age and sex and the FMF group according to colchicine use. We evaluated the quantitative radiomorphometic indices of gonial index, antegonial index, molar cortical thickness, mental index, panoramic mandibular index, and lacunarity, and the qualitative mandibular cortical index on all panoramic radiographs and performed between and within group analysis. RESULTS: Mean gonial index, antegonial index, and molar cortical thickness values of the FMF group were significantly smaller than those of the control group. Significantly fewer patients in the FMF group were classified as mandibular cortical index type 1 compared to the control group. There were no significant differences in quantitative index values according to colchicine use in the FMF group or regarding the categorical parameters of age, sex, and mandibular cortical index classification. CONCLUSIONS: Radiomorphometric values of the mandibular basal cortex posterior to the mental foramen differ significantly in FMF patients compared to healthy counterparts. Dentists should note mandibular morphologic changes indicative of low bone density when examining panoramic images of patients with this disease.

Fractal dimension analysis of different mandibular regions in familial Mediterranean fever patients: A cross-sectional retrospective study.

Familial Mediterranean fever (FMF) is a genetic condition that may cause loss of bone mineral density (BMD) due to chronic inflammation. Previously, fractal dimension (FD) analysis values of mandibular cortical bone were shown to be lower in osteoporosis. Therefore, FD might be considered as an auxiliary tool to refer patients for dual-energy x-ray absorptiometry (DXA), which is the gold standard for BMD measurement. The purpose of this cross-sectional retrospective study was to evaluate trabecular and cortical microarchitecture of the mandible with FD analysis on panoramic radiographs in a subpopulation of FMF. Also, the effect of colchicine use was investigated. Forty-three FMF patients, aged between 10.8 and 71.2 years, and age- and gender-matched control group consisting of patients, who had no systemic diseases, were included. Demographic information such as age and gender, and colchicine use were recorded. In terms of age, the patients were classified as <30 and 30< years. On each panoramic radiographs five regions of interest were selected on the mandible as: 1- premolar, 2- molar, 3- angular, 4- condylar, and 5- basal cortical bone regions on right (R) and left (L) sides. Statistical significance was accepted at p<0.05 level. Intra- and inter-observer agreements demonstrated good to excellent consistency. In FMF patients, L3 and L4 values were higher, whereas L5 values were lower (p<0.05) than the control group. In terms of age, the difference between groups was insignificant in FMF patients (p>0.05), whereas in control group R3 and L4 values were higher in the 30< age group (p<0.05). Regarding gender and colchicine use, the difference between groups was insignificant (p>0.05). FMF disease might be a candidate for referral to DXA examination based on decreased bone density in the mandibular cortex detected by FD measurements on routine panoramic radiographs. Further studies are warranted to ascertain this relationship.

Influence of Acidic Environmental Conditions on Push-Out Bonding Strength of Four Calcium Silicate-Based Materials to Root Dentin.

Introduction: Calcium silicate-based cements (CSCs) are frequently used in various endodontic procedures such as perforation repair, vital pulp therapy, regenerative treatments, or apexification. One of their areas of use, treatment of perforations, can be challenging in clinical practice. Selection of stable, durable, and compatible material with structural and biological alterations is a must in such situations. Aim: This study aimed to compare the dislocation resistance of various calcium-silicate-containing materials used in endodontic treatment exposed to various environmental conditions in a push-out study model. Methods: Selected ninety-six human mandibular premolars with single root canals were cut from the middle portion to obtain dentin slices of 2 mm thickness (n = 192). Then, the canal lumen was enlarged by using #4Gates-Glidden drills. Specimens for each repair material (MTA, Angelus, Endosequence RRM (ERRM), Biodentine, BioMTA) were placed in shaped lumens, wrapped in pieces of gauze, and randomly divided into four groups (n = 48) according to the storage time and media: group A: 4 days in phosphate-buffered saline (PBS), group B: 4 days in acetic acid (pH = 4.4), group C: 34 days in PBS, and group D: 4 days in acetic acid (pH = 4.4) followed by exposure to PBS for 30 days. A universal testing machine measured the dislodgement resistance followed by scanning electron microscopy imaging to evaluate the material-dentin interface. Results: ERRM showed the highest dislocation resistance in all test groups (p < 0.05). The greatest bonding strength was observed (13,54 ± 5,56 MPa) after exposure to 34 days in PBS (pH = 7.2). The values for ERRM decreased in contact with acetic acid (pH = 4.4) and increased when placed in PBS (p > 0.05). Conclusion: All repair materials showed a higher dislocation resistance when stored in PBS regardless of storage time. However, the improved pH of the surrounding media was not successful in reversing the deteriorating effect caused by lower pH in relation to dislocation resistance in all tested materials except for ERRM.

Comparison of different bioglass applications on root caries - A laboratory-based study.

The aim of this in-vitro study was to assess the effect of bioglass with different concentrations on root caries. Ninety freshly-extracted teeth with root caries were randomly assigned to a single-use prophylaxis paste containing 15 % bioglass for 30 s with 1,450 ppmF toothpaste (15 % bioglass, n = 30), 1,450 ppmF toothpaste with 5 % bioglass (5 % bioglass, n = 30), and toothpaste containing 1,450 ppmF (Control, n = 30). Each sample received a standard brushing procedure for 10 s twice a day using the toothpastes. Teeth were immersed in remineralising solution with pH of 7 at 37 °C for 720 h. Surface roughness (Ra) was measured at baseline and after the application of the products at 0.5, 1, 4, 12, 24, 48, 168, 336 and 720 h. Subsequently, three samples from each group were randomly selected to measure calcium ion release over 15 h immersion in deionised water. These samples were then analysed using the SEM for the qualitative assessment of lesion topography. Repeated measures ANOVA, Wilcoxon paired tests and percentage changes were carried out to assess Ra. Calcium ion release data was analysed using one-way ANOVA and Tukey post-hoc tests. After 720 h, 15 % bioglass had the highest decrease in Ra (Mean-difference = 1.502 µm, p = 0.001), then 5 % bioglass (Mean-difference = 0.723 µm, p = 0.09) whereas the control had the lowest Ra decrease (Mean-difference = 0.518 µm, p = 0.55). The differences in Ra between the groups were highly significant (p < 0.001). The cumulative calcium ion release was significantly high for the 5 % bioglass in comparison to the 15 % bioglass, whilst the control had the lowest release (p < 0.001). SEM analysis showed the presence of bioglass particles only on 15 % bioglass samples. The use of prophylaxis paste with 15 % bioglass and 1,450 ppmF toothpaste was promising to reverse/arrest root caries when compared to the toothpaste containing 1,450 ppmF with 5 % bioglass for a period of 30 days.