Efficacy of clinical and radiological methods to identify second mesiobuccal canals in maxillary first molars

Abstract

Introduction. The success of endodontic treatment depends on the identification of all root canals. Technological advances have facilitated this process as well as the assessment of internal anatomical variations. The aim of this study was to compare the efficacy of clinical and radiological methods in locating second mesiobuccal canals (MB2) in maxillary first molars. Methods. Fifty patients referred for analysis; access and clinical analysis; cone-beam endodontic treatment of their maxillary first molars were submitted to the following assessments: analysis; access and clinical analysis; cone-beam computed tomography (CBCT); post-CBCT clinical analysis; clinical analysis using an operating microscope; and clinical analysis after Start X ultrasonic inserts in teeth with negative results in all previous analyses. Results. Periapical radiographic analysis revealed the presence of MB2 in four (8%) teeth, clinical analysis in 25 (50%), CBCT analysis in 27 (54%) and clinical analysis following CBCT and using an operating microscope in 27 (54%) and 29 (58%) teeth, respectively. The use of Start X ultrasonic inserts allowed one to detect two additional teeth with MB2 (62%). According to Vertucci's classification 48% of the mesiobuccal canals found were type I, 28% type II, 18% type IV and 6% type V. Statistical analysis showed no significant differences (p > 0.5) in the ability of CBCT to detect MB2 canals when compared with clinical assessment with or without an operating microscope. A significant difference (p < 0.001)was found only between periapical radiography and clinical/CBCT evaluations. Conclusion. Combined use of different methods increased the detection ofthe second canal in MB roots, but without statistical difference among CBCT, operating microscope, Start X and clinical analysis.     

Bone‐to‐Implant Contact Around Immediately Loaded Direct Laser Metal‐Forming Transitional Implants in Human Posterior Maxilla

Objective: Direct laser metal forming (DLMF) is a procedure in which a high‐power laser beam is directed onto a metal powder bed and programmed to fuse particles according to a computer‐aided design file, generating a thin metal layer. This histologic study evaluated the bone‐to‐implant contact (BIC%) around immediately loaded DLMF transitional implants retrieved after 2 months from posterior human maxillae. Methods: Twelve totally edentulous individuals (mean age, 66.14 ± 2.11 years) received DLMF transitional implants divided in twelve immediately loaded (IL) and twelve unloaded (UI) implants. These transitional implants were placed between conventional implants to support the interim complete maxillary denture during the healing period. After 8 weeks, the transitional implants and the surrounding tissue were removed and prepared for histomorphometric analysis. Results: Mature woven preexisting bone lined by newly formed bone in early stages of maturation were found around all retrieved implants. Histometric evaluation indicated that the mean BIC% was 45.20 ± 7.68% and 34.10 ± 7.85% for IL and UI, respectively (P <0.05). Conclusion: The present data obtained in humans showed that, although both IL and UI presented good BIC%, IL DLMF implants had a higher BIC% in the posterior maxilla.     

不同他汀类药物标准剂量对稳定性斑块的影响

目的探讨不同他汀类药物标准剂量对稳定性斑块的影响。方法入选经冠状动脉造影和血管内超声检查确定为稳定性斑块的135例患者,分为3组：辛伐他汀20mg组47例,阿托伐他汀20mg组45例,瑞舒伐他汀10mg组43例。随访3-6个月,观察给予不同他汀类药物标准剂量的3组血清低密度脂蛋白-胆固醇（10wdensitvlipoprotein-cholesterol,LDL—C）、高密度脂蛋白-胆固醇（highdensitylipoprotein—cholesterol,HDL．C）、高敏C反应蛋白（high—sensitivityC．reactionprotein,hs—CRP）浓度变化及斑块坏死核所占百分比、斑块体积的动态变化。结果3组血清LDL—C、HDL—C、hs．CRP浓度及斑块坏死核所占百分比、斑块体积的基线资料比较,差异无统计学意义（P〉0．05）。随访3-6个月后,他汀类药物标准剂量治疗的3组血清LDL．C浓度与基线相比均有明显下降,均达标（P〈0．01）,且瑞舒伐他汀最优,阿托伐他汀其次,辛伐他汀最后（P均〈0．01）。辛伐他汀组血清HDL-C浓度与基线比较。差异无统计学意义（P〉0．05）,但阿托伐他汀组、瑞舒伐他汀组明显高于基线,差异有统计学意义（P=0．001．P=0．048）,且两组间比较,差异无统计学意义（P=0．852）。辛伐他汀组血清hs—CRP浓度与基线比较,差异无统计学意义（P〉0．05）,但阿托伐他汀组、瑞舒伐他汀组明显低于基线,差异有统计学意义（P=0．015,P=0．025）．且两组间比较,差异无统计学意义（P=0．411）。通过血管内超声虚拟组织成像技术（intravascularuhrasound—virtualhistology,IVUS—vH）检测,斑块坏死核所占百分比在辛伐他汀组明显高于基线,差异有统计学意义（16．33％-＋15．38％眦7．87％-＋1．04％,P〈0．01）;阿托伐汀组治疗后与基线相比,斑块坏死核所占百分比明显减少,差异有统计学意义（6．64％±3．25％帆7．91％±1．27％,P=0．007）;瑞舒伐他汀组斑块坏死核所占百分比与基线相比,差异无统计学意义（P=0．133）。斑块体积在辛伐他汀组治疗前、后比较,差异无统计学意义（P=O．286）;但阿托伐他汀组、瑞舒伐他汀组斑块体积明显低于基线,差异有统计学意义[（28．65±10．77）mm。vs．（33．31±10．75）mm3,P=0．041;（30．69_＋8．12）mm3ys．（36．337-＋12．15）mm。,P=0．013],且治疗后两组体积比较,差异有统计学意义（P=0．322）。结论不同种类他汀类药物标准剂量对稳定性斑块疗效不同：对于LDL—C,辛伐他汀、阿托伐他汀、瑞舒伐他汀标准剂量治疗后均可达标;阿托伐他汀、瑞舒伐他汀能升高HDL—C,降低hs—CRP;辛伐他汀无遏制斑块向不稳定进展的作用,阿托伐他汀有促进斑块稳定,逆转斑块的作用,瑞舒伐他汀可阻止斑块进展及逆转斑块的作用。     

Accuracy of five electronic foramen locators with different operating systems: an ex vivo study

Objective:

The aim of this study was to evaluate, ex vivo, the precision of five electronic root canal length measurement devices (ERCLMDs) with different operating systems: the Root ZX, Mini Apex Locator, Propex II, iPex, and RomiApex A-15, and the possible influence of the positioning of the instrument tips short of the apical foramen.

Material and Methods:

Forty-two mandibular bicuspids had their real canal lengths (RL) previously determined. Electronic measurements were performed 1.0 mm short of the apical foramen (-1.0), followed by measurements at the apical foramen (0.0). The data resulting from the comparison of the ERCLMD measurements and the RL were evaluated by the Wilcoxon and Friedman tests at a significance level of 5%.

Results:

Considering the measurements performed at 0.0 and -1.0, the precision rates for the ERCLMDs were: 73.5% and 47.1% (Root ZX), 73.5% and 55.9% (Mini Apex Locator), 67.6% and 41.1% (Propex II), 61.7% and 44.1% (iPex), and 79.4% and 44.1% (RomiApex A-15), respectively, considering ±0.5 mm of tolerance. Regarding the mean discrepancies, no differences were observed at 0.0; however, in the measurements at -1.0, the iPex, a multi-frequency ERCLMD, had significantly more discrepant readings short of the apical foramen than the other devices, except for the Propex II, which had intermediate results. When the ERCLMDs measurements at -1.0 were compared with those at 0.0, the Propex II, iPex and RomiApex A-15 presented significantly higher discrepancies in their readings.

Conclusions:

Under the conditions of the present study, all the ERCLMDs provided acceptable measurements at the 0.0 position. However, at the -1.0 position, the ERCLMDs had a lower precision, with statistically significant differences for the Propex II, iPex, and RomiApex A-15.     

Epidermal differentiation in embryos of the tuatara Sphenodon punctatus (Reptilia, Sphenodontidae) in comparison with the epidermis of other reptiles

Studying the epidermis in primitive reptiles can provide clues regarding evolution of the epidermis during land adaptation in vertebrates. With this aim, the development of the skin of the relatively primitive reptile Sphenodon punctatus in representative embryonic stages was studied by light and electron microscopy and compared with that of other reptiles previously studied. The dermis organizes into a superficial and deep portion when the epidermis starts to form the first layers. At embryonic stages comparable with those of lizards, only one layer of the inner periderm is formed beneath the outer periderm. This also occurs in lizards and snakes so far studied. The outer and inner periderm form the embryonic epidermis and accumulate thick, coarse filaments (25-30 nm thick) and sparse alpha-keratin filaments as in other reptiles. Beneath the embryonic epidermis an oberhautchen and beta-cells form small horny tips that represent overlapping borders along the margin of beta-cells that overlap other beta-cells (in a tile-like arrangement). The tips resemble those of agamine lizards but at a small scale, forming a lamellate-spinulated pattern as previously described in adult epidermis. The embryonic epidermis matures by the dispersion of coarse filaments among keratin at the end of embryonic development and is shed around hatching. The presence of these matrix organelles in the embryonic epidermis of this primitive reptile further indicates that amniote epidermis acquired interkeratin matrix proteins early for land adaptation. Unlike the condition in lizards and snakes, a shedding complex is not formed in the epidermis of embryonic S. punctatus that is like that of the adult. Therefore, as in chelonians and crocodilians, the epidermis of S. punctatus also represents an initial stage that preceded the evolution of the shedding complex for moulting.     

Radial scars/complex sclerosing lesions and malignancy in a screening programme: incidence and histological features revisited

AIMS: Radial scars (RS) are benign entities, frequently identified on screening mammography, which may be associated with malignancy. Much debate has been generated with regard to the optimum management of RS. We present our experience of RS in the first 5 years of a screening programme. The aim was to evaluate (i) the incidence of atypia and malignancy and (ii) the value of the preoperative core biopsy. We also further characterize the histological features. METHODS AND RESULTS: One hundred and twenty-five histologically confirmed cases of RS were reviewed (111 had preoperative biopsies). Thirty-one (24.8%) patients had a final malignant diagnosis (11 with invasive malignancy) and 28 (22.4%) showed atypia (including lobular carcinoma in situ). In those with core biopsies and a final malignant diagnosis, 12 cases were categorized as B5 (41.3%), three as B4 (10.3%), 12 as B3 (41.3%) and two as B2 (7%). Common histological features included obliterated ducts and chronic inflammation with, less frequently, neural hyperplasia (16.8%) and perineural invasion (3.2%). CONCLUSIONS: The high incidence of atypia and malignancy identified in our study justifies our policy of removing all mammographically detected RS. We emphasize the utility of preoperative core biopsy evaluation in permitting one-stage surgical therapy in those with B5 diagnoses.     

Soft tissue healing at titanium implants coated with type I collagen. An experimental study in dogs

Objective: To analyse the soft tissue healing at titanium implants coated with type 1 collagen. Material and methods: Six dogs were used. The mandibular pre‐molars and the three anterior maxillary pre‐molars were extracted. Three months later mucoperiosteal flaps were raised and two test and two control implants were installed (3i^® TG Osseotite^®3.75 × 10 and 2.8 mm transmucosal collar). The test implants were coated with a purified porcine type I collagen. Cover screws were placed and flaps were sutured. The sutures were removed 2 weeks later and a plaque‐control programme was initiated. Another 2 weeks later, the procedure was repeated in the contra‐lateral mandibular region. Four weeks after the second implant surgery, biopsies were obtained and prepared for histological examination. Results/Conclusion: The vertical dimensions of the epithelial and connective tissue components as well as the composition of the connective tissue portion facing the implant were similar at collagen‐coated and uncoated implants after 4 and 8 weeks of healing. It is suggested that soft tissue healing to implants coated with type I collagen was similar to that at non‐coated titanium implants and that no adverse reactions to the collagen‐coated implants occurred.     

Comparison of the effects of bisphenol a alone and in a combination with X‐irradiation on sperm count and quality in male adult and pubescent mice

Bisphenol A (BPA) is employed in the manufacturing of epoxy, polyester‐styrene, and polycarbonate resins, which are used for the production of baby and water bottles and reusable containers, food and beverage packing, dental fillings and sealants. The study was designed to examine the effects of 8‐week exposure (a full cycle of spermatogenesis) to BPA alone and in a combination with X‐irradiation on the reproductive organs and germ cells of adult and pubescent male mice. Pzh:Sfis male mice were exposed to BPA (5, 10, and 20 mg/kg) or X‐rays (0.05 Gy) or to a combination of both (0.05 Gy + 5 mg/kg bw BPA). The following parameters were examined: sperm count, sperm motility, sperm morphology, and DNA damage in male gametes. Both BPA and X‐rays alone diminished sperm quality. BPA exposure significantly reduced sperm count in pubescent males compared to adult mice, with degenerative changes detected in seminiferous epithelium. This may suggest a higher susceptibility of germ cells of younger males to BPA action. Combined BPA with X‐ray treatment enhanced the harmful effect induced by BPA alone in male germ cells of adult males, whereas low‐dose irradiation showed sometimes protective or additive effects in pubescent mice. © 2013 Wiley Periodicals, Inc. Environ Toxicol 29: 1301–1313, 2014.     

Plasmacytoid variant urothelial bladder cancer: Is it time to update the treatment paradigm?

ObjectivesPlasmacytoid variant (PCV) urothelial cancer (UC) of the bladder is rare, with poor clinical outcomes. We sought to identify factors that may better inform expectations of tumor behavior and improve management options in patients with PCV UC.Materials and methodsA retrospective analysis of the Indiana University Bladder Cancer Database between January 2008 and June 2013 was performed comparing 30 patients with PCV UC at cystectomy to 278 patients with nonvariant (NV) UC at cystectomy who underwent surgery for muscle-invasive disease. Multivariable logistic regression was used to assess precystectomy variables associated with non–organ-confined disease at cystectomy and Cox regression analysis to assess variables associated with mortality.ResultsPatients with PCV UC who were diagnosed with a higher stage at cystectomy (73% pT3-4 vs. 40%, P = 0.001) were more likely to have lymph node involvement (70% vs. 25%, P<0.001), and positive surgical margins were found in 40% of patients with PCV UC vs. 10% of patients with NV UC (P<0.001). Median overall survival and disease-specific survival were 19 and 22 months for PCV, respectively. Median overall survival and disease-specific survival had not been reached for NV at 68 months (P<0.001). Presence of PCV UC on transurethral resection of bladder tumor was associated with non–organ-confined disease (odds ratio = 4.02; 95% CI: 1.06–15.22; P = 0.040), and PCV at cystectomy was associated with increased adjusted risk of mortality (hazard ratio = 2.1; 95% CI: 1.2–3.8; P = 0.016).ConclusionsPCV is an aggressive UC variant, predicting non–organ-confined disease and poor survival. Differentiating between non–muscle- and muscle-invasive disease in patients with PCV UC seems less important than the aggressive nature of this disease. Instead, any evidence of PCV on transurethral resection of bladder tumor may warrant aggressive therapy.