Development of Innovative Contra-angle Handpiece Device with Piston Movement for Root Canal Preparation.

INTRODUCTION: The purpose of this study was to assess the optimal amplitude and weight of the newly developed contra-angle handpiece. The handpiece uses piston movement without using an endodontic motor and enables a safe, quick, and reliable canal preparation. METHODS: A prototype handpiece was designed. Instrumentation was performed on root canal resin blocks by 20 operators in 3 groups: the prototype handpiece with an H file (a stainless steel #25 manual H file, the piston group), a manually standardized technique with a K file (stainless steel #15-25 K files, the manual group), and a nickel-titanium (NiTi) reciprocating file with an endodontic motor (Reciproc Blue R25 [VDW, Munich, Germany], the NiTi group). Transportation of the canal center line and the time required for preparation were measured and statistically analyzed. RESULTS: The optimal condition was an amplitude of 1.35 mm and a weight of 61.0 g. Transportation of the canal center was observed in all groups. A statistically significant difference was found at 2.0-3.0 mm from the apical foramen between the piston or NiTi group and the manual group, but no significant difference was found between the piston and NiTi groups. The least transportation was found in the NiTi and piston groups. The handpiece with a #25 H file demonstrated a good centering ability, similar to the NiTi file, which enabled speedy preparation. The time required for preparation between the piston or NiTi group and the manual group was statistically different. No significant difference was observed between the piston and NiTi groups (P < .05). CONCLUSIONS: We concluded that the newly designed handpiece achieved efficient canal preparation and negotiation. The handpiece could avoid endodontic accidents, including ledge formation, instrument separation, and perforation.

Initial responsiveness to darbepoetin alfa and its contributing factors in non-dialysis chronic kidney disease patients in Japan.

BACKGROUND: Hyporesponsiveness to erythropoiesis-stimulating agents (ESAs) is associated with cardiovascular events and poor renal outcome in patients with chronic kidney disease (CKD). This study aimed to investigate the initial responsiveness to darbepoetin alfa (DA) and its contributing factors using the data from the BRIGHTEN. METHODS: Of 1980 patients enrolled at 168 facilities, 1695 were included in this analysis [285 patients were excluded mainly due to lack of hemoglobin (Hb) values]. The initial ESA response index (iEResI) was defined as a ratio of Hb changes over 12 weeks after DA administration per weight-adjusted total DA dose and contributing factors to iEResI were analyzed. RESULTS: The mean age was 70 ± 12 years (male 58.8%; diabetic nephropathy 27.6%). The median creatinine and mean Hb levels at DA initiation were 2.62 mg/dL and 9.8 g/dL, respectively. The most frequent number of DA administration during 12 weeks was 3 times (41.1%), followed by 4 (15.6%) times with a wide distribution of the total DA dose (15-900 µg). Remarkably, 225 patients (13.3%) did not respond to DA. Multivariate analysis showed that male gender, hypoglycemic agent use, iron supplementation, high eGFR, low Hb, low CRP, low NT-proBNP, and low urinary protein-creatinine ratio were independently associated with better initial response to DA (P = < 0.0001, 0.0108, < 0.0001, 0.0476, < 0.0001, 0.0004, 0.0435, and 0.0009, respectively). CONCLUSIONS: Non-responder to DA accounted for 13.3% of patients with non-dialysis CKD. Iron supplementation, low CRP, low NT-proBNP, and less proteinuria were predictive and modifiable factors associated with better initial response to DA.

Rationale and design of oBservational clinical Research In chronic kidney disease patients with renal anemia: renal proGnosis in patients with Hyporesponsive anemia To Erythropoiesis-stimulating agents, darbepoetiN alfa (BRIGHTEN Trial).

BACKGROUND: Renal anemia is an important complication in non-dialysis chronic kidney disease (CKD) patients as well as in dialysis patients. Although recombinant human erythropoietin has dramatically improved prognosis and quality of life in these patients, there have been issues among non-dialysis CKD patients who exhibit hyporesponsiveness to erythropoiesis-stimulating agent (ESA). The causes and definition of ESA hyporesponsiveness, as well as the incidence of renal and cardiovascular disease (CVD) events in such patients, are yet to be clarified. METHODS: This ongoing trial is a multicenter, prospective, observational study of non-dialysis CKD patients with renal anemia. The primary objective is to survey the current realities of the therapy with ESA in Japan and evaluate the correlation between hyporesponsiveness to darbepoetin alfa and CKD progression. The secondary objective is to investigate relationship between ESA hyporesponsiveness and CVD events based on the clinical situation in Japan, and to explore an ESA response index. RESULTS: The subjects consist of CKD patients with estimated glomerular filtration rate (eGFR) below 60 mL/min/1.73 m2 who present renal anemia. The target number of registered cases is 2000 patients, based on estimates of incidences of renal and CVD events from past studies. Renal function and CVD events will be observed for 96 weeks after the initiation of darbepoetin alfa administration. Definitions of ESA hyporesponsiveness will also be investigated. CONCLUSION: By clarifying markers and factors involved in ESA hyporesponsiveness and their relationships with renal and CVD events, this ongoing study aims to improve evidence-based therapies for renal anemia in non-dialysis CKD patients.

Blood flow speed of the gastric conduit assessed by indocyanine green fluorescence: New predictive evaluation of anastomotic leakage after esophagectomy.

Anastomotic leakage is considered as an independent risk factor for postoperative mortality after esophagectomy, and an insufficient blood flow in the reconstructed conduit may be a risk factor of anastomotic leakage. We investigated the clinical significance of blood flow visualization by indocyanine green (ICG) fluorescence in the gastric conduit as a means of predicting the leakage of esophagogastric anastomosis after esophagectomy.Forty patients who underwent an esophagectomy with gastric conduit reconstruction were prospectively investigated. ICG fluorescence imaging of the gastric conduit was detected by a near-infrared camera system during esophagectomy and correlated with clinical parameters or surgical outcomes.In 25 patients, the flow speed of ICG fluorescence in the gastric conduit wall was simultaneous with that of the greater curvature vessels (simultaneous group), whereas in 15 patients this was slower than that of the greater curvature vessels (delayed group). The reduced speed of ICG fluorescence stream in the gastric conduit wall was associated with intraoperative blood loss (P = 0.008). Although anastomotic leakage was not found in the simultaneous group, it occurred in 7 patients of the delayed group (P < 0.001). A flow speed of ICG fluorescence in the gastric conduit wall of 1.76 cm/s or less was determined by a receiver operating characteristic (ROC) curve, identified as a significant independent predictor of anastomotic leakage after esophagectomy (P = 0.004).This preliminary study demonstrates that intraoperative evaluation of blood flow speed by ICG fluorescence in the gastric conduit wall is a useful means to predict the risk of anastomotic leakage after esophagectomy.

Low calcium intake is associated with high plasma homocysteine levels in postmenopausal women.

Nutritional interventions targeting homocysteine remain controversial, and further nutritional research is warranted. We thus sought to explore the determinants of plasma homocysteine other than B-group vitamins. This cross-sectional study surveyed the nutritional status of 713 Japanese postmenopausal women using a semiquantitative food frequency questionnaire. Associations between total energy, protein, fat, carbohydrate, and vitamin A and K intakes and homocysteine were insignificant. Mean homocysteine in the second (536.1 ± 34.7 mg/day) and third (712.9 ± 115.6 mg/day) tertiles of calcium intake were lower than in the first tertile (379.6 ± 76.6 mg/day) by -0.57 nmol/mL (95 % confidence interval, -1.10 to-0.04, p = 0.04) and -1.18 nmol/mL (-1.76 to -0.60, p<0.01), respectively, after adjustment for lifestyle and clinical factors (trend p\0.01). Mean homocysteine in those with dietary calcium intake above the median (>536 mg/day) were lower regardless of the folic acid concentration; the differences were -1.59 nmol/mL (-2.33 to -0.85, p = 0.02) and -0.75 nmol/mL (-1.37 to-0.12, p<0.01) for the high (<7.8 ng/mL) and low folic acid groups, respectively. There was no significant association between calcium and folic acid (p = 0.08). In conclusion, further prospective research to confirm our findings is needed for the development of nutritional inventions targeting homocysteine.

Serum 25-hydroxyvitamin D below 25 ng/mL is a risk factor for long bone fracture comparable to bone mineral density in Japanese postmenopausal women.

There is emergent evidence for divergent associations between 25(OH)D levels and fractures by race and ethnicity, but data on Asian populations are sparse. We investigated this association in a primary care cohort of 1470 postmenopausal Japanese women followed for a mean period of 7.2 years and explored a potential threshold of 25(OH)D. Endpoints were incident vertebral, proximal femur, and long bone fractures. Rate ratios were estimated using multivariate Poisson regression adjusted for lumbar or femur bone mineral density (BMD) less than -2.5 SD of the young adult mean (YAM), age, weight, presence of diabetes mellitus, parathyroid hormone, estimated glomerular filtration rate, prior fracture, back pain, present medications and past medical history. Mean age was 63.7 ± 10.7 years and osteoporosis patients were 41.3 %. The background data of the present participants were almost identical to the subjects participating in the National Health and Nutrition Survey of 2003. Overall, 49.6 % of the subjects had a 25(OH)D value <20 ng/mL and 27.8 % had a 25(OH)D value from 20 to 24 ng/mL. The propensity score for exposure to 25(OH)D < 25 ng/mL in the present and independent community dwelling populations, namely the Miyama and Taiji cohorts, were not significantly different, suggesting no evidence for selection bias. The generalized additive models showed clear decreasing trends in incidence rates of proximal femur and long bone fractures at higher levels of 25(OH)D, and the annual incidence rate of proximal femur fracture was around 0.0005 in women with 25(OH)D > 25 ng/mL, probably leading to the decreasing trend in long bone fracture. Multivariate-adjusted rate ratios of 25(OH)D < 25 ng/mL were 1.01 (95 % confidence interval [CI], 0.84-1.22, p = 0.88) for vertebral fracture, 2.71 (95 % CI 0.94-7.83, p = 0.07) for proximal femur fracture, and 2.20 (95 % CI 1.37-3.53, p < 0.01) for long bone fracture. The respective rate ratios of a BMD level lower than -2.5 SD of the YAM were 1.61 (95 % CI 1.33-1.94, p < 0.01), 1.52 (95 % CI 0.67-3.45, p = 0.32), and 1.54 (95 % CI 1.02-2.33, p = 0.04). In conclusion, 25(OH)D is a leading risk factor for long bone fracture comparable to BMD in Japanese postmenopausal women. The contribution of 25(OH)D to fracture risks is substantial even below 25 ng/mL and is possibly site-specific. We recommend measuring the serum 25(OH)D level in primary care settings.

Clinical performance of dental fiberscope image guided system for endodontic treatment.

We developed a dental fiberscope that can be navigated. As a result we are able to better grasp the device position relative to the teeth, aiming at the lesion more precisely. However, the device position and the precise target setting were difficult to consistently ascertain. The aim of this study is to navigate the position of tip of the dental fiberscope fiber in the root canal with our navigation system. A 3D tooth model was made from the raw dental CT data. In addition, the optical position of the measurement device, OPTOTRAK system was used for registration of the 3D model and actual teeth position and to chase the scope movement. We developed exclusive software to unify information. We were subsequently able to precisely indicate the relation of the position between the device and the teeth on the 3D model in the monitor. This allowed us to aim at the lesion more precisely, as the revised endoscopic image matched the 3D model. The application of this endoscopic navigation system could increase the success rate for root canal treatments with recalcitrant lesion.

High level of serum undercarboxylated osteocalcin in patients with incident fractures during bisphosphonate treatment.

To evaluate the possible interaction of metabolic effects in the mevalonate pathway between amino-bisphosphonates (amino-BP) and vitamin K, the serum level of undercarboxylated osteocalcin (ucOC) was measured in amino-BP users in relationship to incident fracture occurrence. Osteoporotic patients (mean age, 70.7 +/- 9.1 years; n = 231) treated with alendronate or risedronate were followed for 3.4 +/- 2.1 years, and observations regarding the presence or absence of incident fractures in their vertebrae were made based on vertebral X-ray films every year. During the observation period, new fractures were found in a total of 71 patients (incident vertebral fracture, n = 61; the remaining 10 patients had long bone fractures). The baseline data of the patients with incident fractures indicated that incident fractures are more likely to occur in older patients who have a higher number of prevalent vertebral fractures and lower baseline lumbar bone mineral density (LBMD) as compared to patients without incident fractures. There was no significant difference in the changes of LBMD and urinary excretion of NTX after treatment. On the other hand, the serum level of ucOC in patients with incident fractures and with amino-BP treatment was significantly higher (2.75 +/- 0.19 ng/ml) than that in patients without incident fractures and with amino-BP treatment (2.28 +/- 0.13 ng/ml) (P = 0.038). These results indicate that older age, a greater number of prevalent fractures and higher ucOC levels, and lower LBMD are risks for incident fractures despite use of amino-BP. The time-dependent incident fracture rate was higher in accordance with an increase in the number of risk items (P < 0.001 in log-rank and Wilcoxon tests). In conclusion, measurement of undercarboxylated osteocalcin may be useful for assessing fracture risk in patients receiving amino-BP treatment.

Dental fiberscope with navigation system for endodontic treatments.

We developed a dental fiberscope with a navigation system. The aim of this study is to direct the position of the tip of the endoscope fiber in the root canal via our navigation system. The distinguishing characteristic of our system is that it could be particularly practical in narrow spaces, such as those involving endodontic treatment typical of root canals. We were subsequently able to precisely indicate the relation of the position between the device and the teeth on the 3D model on the monitor. We inspected our navigation system using both the phantom model and the reconstructed 3D model. From this we could comprehend the relation of the position between the teeth and the device, and aim precisely at the lesion. If we are able to realize the correct position of the endoscope, we can safely and accurately deliver laser irradiation to the lesion. Consequently, the application of the endoscopic navigation system could increase the success rate for root canal treatments with recalcitrant lesions.

Minimally invasive periapical curettage of foreign materials in periapical lesions using a fiberscope.

The design and development of a new fine fiberscope (1.0 mm outer diameter) is described, that includes an irrigation system for endoscopic use. This effectively allows visualisation of fields involved in periodontal disease. This fiberscope has been used in our clinic for seven years to diagnose and treat periapical and periodontal lesions through fistulae and periodontal pockets. The fiberscope has been applied to endodontic surgery for the inspection of root apices and the denuded root surfaces, in addition to the cut root face, rootend cavity and root-end filling after root-end resection. The advantages of endoscopy compared to surgical microscopy are portability and easy adjustment of direct viewing angle to examine around corners without the use of additional mirrors. Furthermore, the fiberscope can be utilised through the sinus tract or a minimal incision without the need for surgical flaps to observe the root surface, periapical tissue and foreign materials before, during and after curettage. The system requires little local anaesthesia, no large incisions, no opening flaps and no sutures. As a result, postoperative symptoms are minimised. Periapical curettage using a fiberscope represents a useful and minimally invasive surgical procedure.