Subregional DXA-derived vertebral bone mineral measures are stronger predictors of failure load in specimens with lower areal bone mineral density, compared to those with higher areal bone mineral density

Measurement of areal bone mineral density (aBMD) in intravertebral subregions may increase the diagnostic sensitivity of dual-energy X-ray absorptiometry (DXA)-derived parameters for vertebral fragility. This study investigated whether DXA-derived bone parameters in vertebral subregions were better predictors of vertebral bone strength in specimens with low aBMD, compared to those with higher aBMD. Twenty-five lumbar vertebrae (15 embalmed and 10 fresh-frozen) were scanned with posteroanterior- (PA) and lateral-projection DXA, and then mechanically tested in compression to ultimate failure. Whole-vertebral aBMD and bone mineral content (BMC) were measured from the PA- and lateral-projection scans and within 6 intravertebral subregions. Multivariate regression was used to predict ultimate failure load by BMC, adjusted for vertebral size and specimen fixation status across the whole specimen set, and when subgrouped into specimens with low aBMD and high aBMD. Adjusted BMC explained a substantial proportion of variance in ultimate vertebral load, when measured over the whole vertebral area in lateral projection (adjusted R2 0.84) and across the six subregions (ROIs 2–7) (adjusted R2 range 0.58–0.78). The association between adjusted BMC, either measured subregionally or across the whole vertebral area, and vertebral failure load, was increased for the subgroup of specimens with identified ‘low aBMD’, compared to those with ‘high aBMD’, particularly in the anterior subregion where the adjusted R2 differed by 0.44. The relative contribution of BMC measured in vertebral subregions to ultimate failure load is greater among specimens with lower aBMD, compared to those with higher aBMD, particularly in the anterior subregion of the vertebral body

Assessment of the prevalence of radix entomolaris and distolingual canal in mandibular first molars in 15 countries: a multinational cross-sectional study with meta-analysis

Aim: The aim of this study was two-folded: i) to assess the prevalence of Distolingual Canal (DLC) and Radix Entomolaris (RE) in Mandibular First Molars (M1Ms), using Cone Beam Computed Tomography (CBCT) images and ii) to assess the impact of sociodemographic factors on the prevalence of these conditions worldwide. Methods: CBCT images were scanned retrospectively and the ones including bilateral M1Ms were included in the study. The evaluation was performed by 1 researcher in each country, trained with CBCT technology. A written and video instruction program explaining the protocol to be followed step-by-step was provided to all observers to calibrate them. The CBCT imaging screening procedure consisted of evaluating axial sections from coronal to apical. The presence of DLC and RE in M1Ms (yes/no) was identified and recorded. Results: Six thousand three hundred four CBCTs, representing 12,608 M1Ms, were evaluated. A significant difference was found between countries regarding the prevalence of both RE and DLC (P .05). Conclusion: The overall prevalence of RE and DLC in M1Ms was 3% and 22%. Additionally, both RE and DLC showed substantial bilaterally. These variations should be considered by endodontic clinicians during endodontic procedures in order to avoid potential complications

Pain after single-visit root canal treatment with two single-file systems based on different kinematics—a prospective randomized multicenter clinical study

© 2015, Springer-Verlag Berlin Heidelberg.Objectives: The aim of this study is to evaluate the posttreatment pain after instrumentation of root canals with a single-file reciprocating (RECIPROC, VDW, Germany) or rotary (One Shape, MicroMega, France) file system. Materials and methods: Six hundred forty patients were assessed for eligibility, and 624 patients were included in this study. The teeth were randomly allocated to one of the instrumentation protocols. The teeth underwent routine root canal treatment after which patients were discharged with a questionnaire to gather data about the incidence (yes/no), nature (mild, moderate, or severe), and duration of pain (days). The data were analyzed using statistical analyses (preoperative pain scores by Mann-Whitney U test, incidence and intensity of pain by chi-squared test, intake of analgesics, and duration of pain by Student’s t test) with P = 0.05. Results: Pain analysis was performed for 605 patients (311 males and 294 females) as 5 patients were excluded due to sealer extrusion and 14 were lost to follow-up. The mean age of the patients was 31 ± 2 years. There was significant difference in the incidence of postoperative pain (P < 0.001). There was significant difference in the number of patients who had mild (P = 0.001), moderate (P = 0.002), and severe (P = 0.001) pain between the two groups. Intensity of pain showed significant difference, with patients in the One Shape group (40.5 %) reporting more values of severe pain (P = 0.002); the percentage of patients who took analgesics was significantly higher in the One Shape group (40.5 %) than in the Reciproc group (19.3 %) (P = 0.002). There was no significant difference in the duration of postoperative pain between the two groups when the pain was mild (P = 0.301), but One shape showed significantly longer duration of moderate (P = 0.001) and severe pain (P = 0.002). Conclusions: Reciproc showed significantly less intensity and duration of posttreatment pain compared to One Shape. Clinical relevance: Reciprocation movement offers a more predictable and safer approach of root canal preparation, in addition to producing less postoperative pain. The need for patients to take analgesics may reduce following this approach.Link_to_subscribed_fulltex