Apical extrusion of Enterococcus faecalis in different canal geometries during the use of nickel titanium systems with different motion types.

BACKGROUND/PURPOSE: Extrusion of intracanal bacteria leads to treatment failures. Compare the apical extrusion of intracanal bacteria (Enterococcus faecalis) during canal preparation with three different instrumentation techniques [RECIPROC, One Shape (OS), and Twisted-File Adaptive (TFA)] with different motion types. MATERIALS AND METHODS: Ninety teeth with different canal morphologies were divided into three main groups, each including 30 teeth (10 mandibular incisors, 10 mandibular premolars, and 10 curved roots). Roots were resected until 13-mm working length was obtained and fixed to glass vials filled with brain-heart infusion broth. Each canal was filled with E. faecalis suspension. The three main groups were further grouped into three subgroups. Each group was further subgrouped into three, with each subgroup including 10 roots from each type of teeth (10 incisors/subgroup, 10 premolars/subgroup, and 10 curved canals/subgroup). These subgroups were prepared with one of RECIPROC, OS, or TFA. Bacterial colonies extruded into each vial were incubated in brain-heart infusion agar at 37°C for 5 days and counted using a colony counter as the number of colony-forming units per milliliter. Statistical analyses were performed using one-way analysis of variance, post hoc Tukey honest significant difference, and Kruskal-Wallis tests. RESULTS: Apically extruded bacteria were not statistically different from each other (P > 0.05). The amount of apically extruded bacteria was statistically similar for both different instruments in the same type of tooth (P > 0.05) and same instrument in different types of teeth (P > 0.05). CONCLUSION: Neither the motion type of instrument nor the canal morphology affected the degree of bacterial extrusion.

Detection of Second Mesiobuccal Canals in Maxillary First Molars Using a New Angle of Cone Beam Computed Tomography.

BACKGROUND: The localization of the additional canal orifice is one of the primary factors influencing the success of endodontic treatment. To deal with this problem, several techniques that each have their own advantages and disadvantages have been discussed in the literature. OBJECTIVES: The aim of the present in vitro study was to review a new approach to localizing second mesiobuccal (MB2) canals in maxillary first molars using cone beam computed tomography (CBCT). PATIENTS AND METHODS: The CBCT scans of 296 patients who were referred to the department of dentomaxillofacial radiology were included in the study. The presence of MB2 canals, the angle formed by the mesiobuccal, distobuccal, and palatal root canal orifices (∠MDP), and the angle formed by the mesiobuccal, distobuccal, and MB2 canal orifices (∠MDMB2) were evaluated on the axial section. Pearson correlation and multiple linear regression methods were used for all predictions. All of the analyses were performed using SPSS for windows version 22.0. A two-sided P value < 0.05 was defined as statistically significant. RESULTS: Of the 468 first molars, MB2 canals were observed in 296 subjects (141 females and 155 males). There were no statistically significant differences between females and males (P = 0.300). The ∠MDP and ∠MDMB2 were detected and evaluated. A moderate positive correlation was found between the ∠MDP and the ∠MDMB2. To predict the ∠MDMB2 values, it was shown that the ∠MDMB2 increased by 0.420 degrees when the ∠MDP increased by 1 degree. If the ∠MDP was greater than 90.95 degrees, there was a 78% probability that MB2 canals could be found. CONCLUSION: The determination of the presence of MB2 in the maxillary first molars may be carried out using CBCT scans. If the ∠MDP was 91 degrees or greater, there was considered to be a higher probability that MB2 canals would be found in the endodontic cavity. Due to the positive correlation between the ∠MDP and the ∠MDMB2, the localization of MB2 canals may be easily performed in relation to the main MB canal.

The combined occluding effect of sodium fluoride varnish and Nd:YAG laser irradiation on dentinal tubules-A CLSM and SEM study.

The purpose of this study is to evaluate the dentinal tubule occlusion potential and penetration of Clinpro® White Varnish (5% sodium fluoride + tri-calcium phosphate) in the presence or absence of Nd:YAG laser. Seventy-five dentin samples collected from 38 freshly extracted human molars were randomly divided into five groups (n = 15). Groups A, B, D, and E were varnished with Clinpro, whereas group C (no treatment) served as the control group. Groups B and E were further irradiated with Nd:YAG laser (1.5 W, 10 Hz, 1 min). All study groups were subjected to pH cycling (kept in 0.3% citric acid 5 min/day for 5 days). Groups A, B, and C were evaluated for tubule occlusion using scanning electron microscopy. Groups D and E were evaluated for penetration with confocal laser scanning microscopy (SEM). Non-parametric Kruskall-Wallis and Dunn's statistical tests were used for analysis of SEM results. The penetration depths were analyzed with one-way ANOVA followed by Fisher's Least Significant Difference tests. Tubular occlusion of groups A and B were significantly greater than group C (p < 0.05). Tubular occlusion of group B were significantly greater than group A (p < 0.05). Penetration depth for group D was significantly greater than group E (p < 0.05). Laser application improved the tubular occlusion capacity of Clinpro. Contrary, laser reduced the penetration of Clinpro. SCANNING 38:619-624, 2016. © 2016 Wiley Periodicals, Inc.

Effect of fibre-reinforced composite on the fracture resistance of endodontically treated teeth.

The aim of this study is to evaluate the fracture resistance of root-filled teeth restored with fibre-reinforced composite (everX posterior). Fifty mandibular molars were divided into five groups (n = 10). Group 1: no treatment was applied (intact teeth). Group 2-5: canals were prepared and root filled. Group 2: no coronal restoration was placed. Group 3: teeth were coronally restored with composite. Group 4: composite restorations were performed following polyethylene fibre insertion at the cavity base. Group 5: composite resin placed over everX posterior. After thermocycling (5-55°C, 5000×), fracture resistance was measured. Mean force load for each sample was recorded in Newtons (N). Results were statistically analysed with one-way analysis of variance and post hoc Tukey's tests. The mean force required to fracture samples and standard deviations are as follows: group 1: 2859.5 ± 551.27 N, group 2: 318.97 ± 108.67 N, group 3: 1489.5 ± 505.04 N, group 4: 1958.3 ± 362.94 N, group 5: 2550.7 ± 586.1 N. everX posterior (group 5) was higher than groups 2, 3 and 4 (P < 0.05). There were no significant differences between everX posterior and intact teeth (P > 0.05). Placing fibre-reinforced composite under composite increased the fracture strength of root-filled teeth to the level of intact teeth.

Intranodal palisaded myofibroblastoma; a case report and review of the literature.

Intranodal palisaded myofibroblastoma (IPM) also called as intranodal hemorrhagic spindle cell tumor with amianthoid fibers is a distinctive and rare mesenchymal neoplasm of lymph nodes. This entity generally misdiagnosed as intranodal Kaposi's sarcoma or schwannoma in past. In contrast to Kaposi's sarcoma, it behaves in a benign fashion and does not need any further therapy except total surgical resection of the mass. This neoplasm has a great predilection for the inguinal region. The lesion presents typically as a unilateral, painless, solitary mass. To our knowledge, approximately 53 cases of IPM have been reported in the English-language literature. We present a 43-year-old-male patient with IPM and discuss histological, immunohistochemical features and pathogenesis of this rare benign neoplasm.

Evaluation of osteogenic and chondrogenic activities of prefabricated periallografts.

Reconstruction of cartilage and bone defects has always been a challenging problem for the surgeon. Basic elements that are responsible for the repair process of these tissues are periost and perichondrium. Although several methods for the use of periost and perichondrium are proposed in the literature, the osteogenic and chondrogenic capacities of these tissues were shown to be the most important factor for a successful outcome. Bone and cartilage formation in acellular dermal matrix (ADM) prefabricated with periost and perichondrium was studied in 20 New Zealand rabbits. Morphologic and histologic evaluation and comparison of the newly formed tissues were evaluated. Four rabbits were excluded from the study because of infection, and specimens were obtained at 4, 6, 8, and 12 weeks after the study began from the remaining 16 rabbits. A gradual increase in bone and cartilage tissue formation through the 4th to 12th weeks was documented by reason of perichondrium and periost activation infiltrating into acellular dermal allografts. In view of the data obtained, it was concluded that periost or perichondrium prefabricated over ADM may be an alternative technique of cartilage and bone formation that may provide adequate tissue with elastic and osteo- and chondroconductive properties for the reconstruction of challenging defects.

Adenoid-basal cell tumor of the prostate gland. A case report: histomorphologic and immunohistochemical features.

Lesions with basaloid features are very rare and controversial within the prostate gland. There seems to be a morphologic continuum ranging from focal basal cell hyperplasia (BCH) to florid adenoid basal cell tumor (ABCT). The clinicopathological features of a basaloid lesion which was associated with an acinar prostatic carcinoma of the prostate gland are described in a 74-year-old man, and discussed under the light of the literature.