Chapter 8 : Experimental Studies of Root Canal Therapy for Infected Nonvital Permanent Teeth with Incompletely Formed Apices

A total of 160 root canals in 90 teeth with incompletely formed roots of puppies were prepared for infected root canal therapy. The experimental group was treated with Vitapex and the control group was treated with calcium hydroxide-CMCP paste root canal filling material. Histopathological sections from decalcified specimens were prepared after observation periods of 30, 60, 120 and 180 days. In addition, 24 root canals in 16 teeth were treated with Vitapex on the opposite side with sound teeth and subjected to tetracycline administration. Observations were carried out by contact microradiography and tetracycline labeling and resulted in the following conclusions. 1: Almost no root growth was observed using both root canal filling materials, and the addition of newly-formed hard tissue was observed close to the root apical foramen involved. 2: The addition of hard tissue after root canal filling was thought to be primarily by cementum. 3: A greater amount of hard tissue formation resulting in closure of the apex and a more favorable outcome was observed in the control group than in the experimental group. 4: The control group had a higher percentage of hard tissue formation outside the root apex close to the root tip than did the experimental group. 5: The experimental group showed good results in each observation period. The control group showed better results with a shorter observation period than did the experimental group, but in longer observation periods, tended to decrease in cases with poor results. 6: Undecalcified specimens were examined using contact microradiography and tetracycline labeling. In the experimental group, the addition of newly-formed hard tissue was observed close to the apical foramen near the root tip formed during the course of treatment. Normal root formation in the dental arch was observed in all samples in the experimental and control groups.Editor, Toshiyuki KawakamiLanguage Editor, David M Carlsonviii, 232 p. ill. (some col.

Chapter 6 : Histopathological Studies of Pulpectomy in the Deciduous Teeth of Dogs

A study was performed to examine the impact of resorbable root canal filling material, Vitapex, containing calcium hydroxide and iodoform, on the physiological resorption of its roots, succedaneous permanent tooth buds and periodontal tissues. A total of 14 puppies aged 2-5 months were used; teeth were anesthetized, pulps were extirpated and immediate root canal filling was performed. These procedures were carried out in 53 deciduous teeth with 81 root canals, and contralateral intact teeth were used as controls. The animals were bred for 5 to 60 days and were tracked with radiographical and histological examinations. Results obtained were the following: 1: The form of healing observed after the experimental procedures was divided into 2 groups: those healed either by remaining vital pulp tissue or by the periodontal ligament, with 17 and 29 cases, respectively. 2: The resorption of root canal filling material and the physiological root resorption were almost the same in the majority of cases. 3: The rate of physiological root resorption in the experimental group was slightly delayed compared to that of the control group. 4: The remaining pulp tissue lesions, either in short or long term cases, comprised 5 cases of congestion, 3 cases of hemorrhage, 5 cases of mild inflammation, 11 cases of purulent inflammation, and 1 case of atrophy. 5: Periapical lesions, either in short or long term cases, comprised 6 cases with congestion, 12 cases with mild inflammation, 17 cases with purulent inflammation and 7 cases with pathological alveolar bone resorption. 6: In most cases, the lesions did not significantly affect the permanent tooth buds, except for 6 of 81 cases. 7: Pathological grades obtained in this experiment, in a total of 81 cases, were good in 41 cases (50.6%), fair in 20 cases (24.7%) and a failure in 20 cases (24.7%). 8: The best pathological grades after the experimental procedure were obtained in cases in which the root canal filling material was limited within the canal itself (flush) and in those cases which were underfilled. Overextension of root canal filling should be avoided as much as possible. 9: The relationship between root status and pathological grades showed a slightly lower incidence and favorable results with physiological root resorption compared to those without physiological root resorption. 10: In this study, the use of Vitapex for immediate root canal filling after pulp extirpation in canine deciduous teeth produced good results. Vitality of the remaining pulp and periodontal tissue was restored with subsequent physiological root resorption and without adverse effect on succedaneous permanent tooth buds.Editor, Toshiyuki KawakamiLanguage Editor, David M Carlsonviii, 232 p. ill. (some col.

Chapter 9 : Clinical and Radiographic Observation of Permanent Teeth with Incompletely Formed Roots after Root Canal Therapy

A total of 33 teeth with 66 root canals were clinically diagnosed as irreversible pulpitis, and 38 teeth with 53 canals were diagnosed as apical periodontitis. Those 71 teeth had 119 root canals, with incompletely formed roots, and they underwent root canal therapy and filling using a formulation of calcium hydroxide and iodoform called Vitapex and were clinically observed for 30 to 1312 days. The following are the results and conclusions. 1: After root canal therapy, the condition of the root canal filling material was determined by radiograph In 66 root canals with irreversible pulpitis, 16 cases were overfilled, 11 cases were flush and 39 cases were underfilled. In 53 cases with apical periodontitis, 28 cases were overfilled, 10 cases were flush and 15 cases were underfilled. 2: Clinical discomfort was experienced in 10 cases with irreversible pulpitis and in 3 cases with apical periodontitis. However, most of the discomfort was of a mild degree and disappeared within a week. 3: At the last observation, a high frequency of closure of the root apex was observed by radiograph. Cases with apical periodontitis tend to have a slight delay in inducing closure of the root apex compared with cases with irreversible pulpitis. However, after 540 days, closure of the root apex was observed in all cases. 4: Clinical and radiographic findings show that in 33 cases with irreversible pulpitis, 23 cases were good, 9 cases were fair and 1 case was poor. On the other hand, in 38 cases with apical periodontitis, 35 cases were good, 2 cases were fair and 1 case was poor.Editor, Toshiyuki KawakamiLanguage Editor, David M Carlsonviii, 232 p. ill. (some col.

Chapter 7 : Clinical and Radiographic Examinations of Pulpectomy in Deciduous Teeth

Clinical and radiographic examinations were done on 163 deciduous teeth treated with a root canal filling material called Vitapex, which contains calcium hydroxide and iodoform. Anesthesia was administered, followed by pulp extirpation and immediate root canal filling, with observation for 5 to 1307 days. The following results were obtained. 1: Excessive bleeding during pulp extirpation seemed to adversely affect the overall clinical and radiographic results. The poor clinical condition of the pulp resulted in a higher incidence of poor results based on radiographs. 2: Deciduous teeth are susceptible to overfilling after a certain period due to root resorption. A higher incidence of good pathological scores was obtained when the root canal filling was flush, not overfilled. Radiographs confirmed resorption of excess root canal filling material in all cases. 3: During the observation period, root canal filling materials were in a stable condition and only few roots exhibited resorption. Root resorption occurred earlier or at the same time as the resorption of root canal filling material. 4: During the observation period, eruption of the succeeding permanent teeth was observed in 18 cases. In 12 out of 18 cases, eruption of the succeeding tooth did not occur at the same time as on the contralateral side (control). In 6 out of 12 cases, eruption of the succeeding permanent tooth was earlier than on the contralateral side but in 4 out of 12 cases, a delay in the replacement was observed. Also, 2 cases were replaced almost immediately. 5: During the observation period, pathological root resorption was observed in cases where root canal filling material was rapidly resorbed. 6: Until the last observation day, 127 out of 163 cases (77.9%) showed no clinical discomfort or adverse radiographic findings and only 36 out of 163 cases (22.1%) showed some discomfort. 7: Signs and symptoms observed in the study were the following: 5 cases of spontaneous pain, 3 cases of pain during mastication, 10 cases of pain on percussion, 3 cases of gingival swelling, 1 case of redness, 1 case of tenderness, 3 cases of fistula and 3 cases of drainage. Discomfort was felt from the 1st to 3rd day after treatment and was mostly of a mild degree. 8: Radiographic findings of those with clinical discomfort were the following: 2 cases with loss of lamina dura, 12 cases with incomplete resorption, 8 cases with root resorption and 5 cases with pathological lesion. 9: In 36 cases with clinical discomfort and adverse radiographic findings, 12 cases (33.3%) had clinical discomfort only, 17 cases (47.2%) had clinical discomfort associated with adverse radiographic findings and 7 cases (19.5%) were asymptomatic but with adverse radiographic findings. Adverse radiographic findings were observed in 13 out of 91 cases (14.3%) in anterior and 23 out of 72 cases (31. 9%) in posterior teeth. The clinical diagnosis of cases with adverse radiographic findings was observed in the most infectious pulpitis particularly acute suppurative pulpitis and chronic hyperplastic pulpitis. 10: The overall clinical and radiographic results obtained in the study were the following: out of 163 cases, 127 obtained good results (77.9%) and 25 cases were fair (15.3%) for a total of 93. 2% had satisfactory results. Only 11 cases had poor results (6. 8%). In 151 cases with stable periodontal tissue condition from the radiograph, 117 cases obtained good results (77. 5%), 23 cases were fair (15. 2%) and 11 cases were poor (7. 3%). Resorption of about 1/4 to 2/3 of the root occurred in 12 cases, in which 10 cases obtained good results (83.3%), 2 cases were fair (16.7%) and none of the cases was classified as poor. Root canal filling immediately after anesthesia and pulp extirpation in cases with advanced root resorption was thought to be significant. 11: There was no change in the condition of the root in 92 cases until the last observation day. In 92 cases, 72 cases obtained good results (78.3%), 9 cases were fair (9.8%) and 11 cases were poor (11. 9%). The remainder of the 59 cases with root resorption became stable within the observation period. In 59 cases, 45 cases obtained good results (76.3%), 14 cases were fair (23.7%) and no case was classified as poor. Vitapex employed in root canal filling of deciduous teeth mostly did not induce clinical signs and symptoms, and adverse radiographic findings as well as affecting physiological root resorption confirming that this is an excellent root canal filling material.Editor, Toshiyuki KawakamiLanguage Editor, David M Carlsonviii, 232 p. ill. (some col.

Theory of tunneling spectroscopy in superconducting Sr2RuO4

A theory for tunneling spectroscopy in normal metal /insulator/triplet superconductor junction is presented. We assume two kinds of non-unitary triplet superconducting states which are the most promising states for Sr$_{2}$RuO$_{4}$. The calculated conductance spectra showzero-bias peaks as well as gap structures. The existences of residual components in the spectra reflect the non-unitary properties of superconducting states.Comment: 5pages, 4figures(included), to be published in Phys.Rev.B 56, (1997

Theory of Macroscopic Quantum Tunneling in High-T_c c-Axis Josephson Junctions

We study macroscopic quantum tunneling (MQT) in c-axis twist Josephson junctions made of high-T_c superconductors in order to clarify the influence of the anisotropic order parameter symmetry (OPS) on MQT. The dependence of the MQT rate on the twist angle $\gamma$ about the c-axis is calculated by using the functional integral and the bounce method. Due to the d-wave OPS, the $\gamma$ dependence of standard deviation of the switching current distribution and the crossover temperature from thermal activation to MQT are found to be given by $\cos2\gamma$ and $\sqrt{\cos2\gamma}$, respectively. We also show that a dissipative effect resulting from the nodal quasiparticle excitation on MQT is negligibly small, which is consistent with recent MQT experiments using Bi${}_2$Sr${}_2$CaCu${}_2$O${}_{8 + \delta}$ intrinsic junctions. These results indicate that MQT in c-axis twist junctions becomes a useful experimental tool for testing the OPS of high-T_c materials at low temperature, and suggest high potential of such junctions for qubit applications.Comment: 15 pages, 8 figures, 1 tabl

Impact of a learning health system on acute care and medical complications after intracerebral hemorrhage

Introduction: Patients with stroke often experience pneumonia during the acute stage after stroke onset. Oral care may be effective in reducing the risk of stroke‐associated pneumonia (SAP). We aimed to determine the changes in oral care, as well as the incidence of SAP, in patients with intracerebral hemorrhage, following implementation of a learning health system in our hospital. Methods: We retrospectively analyzed the data of 1716 patients with intracerebral hemorrhage who were hospitalized at a single stroke center in Japan between January 2012 and December 2018. Data were stratified on the basis of three periods of evolving oral care: period A, during which conventional, empirically driven oral care was provided (n = 725); period B, during which standardized oral care was introduced, with SAP prophylaxis based on known risk factors (n = 469); and period C, during which oral care was risk‐appropriate based on learning health system data (n = 522). Logistic regression analysis was performed to evaluate associations between each of the three treatment approaches and the risk of SAP. Results: Among the included patients, the mean age was 71.3 ± 13.6 years; 52.6% of patients were men. During the course of each period, the frequency of oral care within 24 hours of admission increased (P < .001), as did the adherence rate to oral care ≥3 times per day (P < .001). After adjustment for confounding factors, a change in the risk of SAP was not observed in period B; however, the risk significantly decreased in period C (odds ratio 0.61; 95% confidence interval 0.43‐0.87) compared with period A. These associations were maintained for SAP diagnosed using strict clinical criteria or after exclusion of 174 patients who underwent neurosurgical treatment. Conclusions: Risk‐appropriate care informed by the use of learning health system data could improve care and potentially reduce the risk of SAP in patients with intracerebral hemorrhage in the acute stage

Methane Emission Estimates by the Global High-Resolution Inverse Model Using National Inventories

We present a global 0.1° × 0.1° high-resolution inverse model, NIES-TM-FLEXPART-VAR (NTFVAR), and a methane emission evaluation using the Greenhouse Gas Observing Satellite (GOSAT) satellite and ground-based observations from 2010–2012. Prior fluxes contained two variants of anthropogenic emissions, Emissions Database for Global Atmospheric Research (EDGAR) v4.3.2 and adjusted EDGAR v4.3.2 which were scaled to match the country totals by national reports to the United Nations Framework Convention on Climate Change (UNFCCC), augmented by biomass burning emissions from Global Fire Assimilation System (GFASv1.2) and wetlands Vegetation Integrative Simulator for Trace Gases (VISIT). The ratio of the UNFCCC-adjusted global anthropogenic emissions to EDGAR is 98%. This varies by region: 200% in Russia, 84% in China, and 62% in India. By changing prior emissions from EDGAR to UNFCCC-adjusted values, the optimized total emissions increased from 36.2 to 46 Tg CH4 yr−1 for Russia, 12.8 to 14.3 Tg CH4 yr−1 for temperate South America, and 43.2 to 44.9 Tg CH4 yr−1 for contiguous USA, and the values decrease from 54 to 51.3 Tg CH4 yr−1 for China, 26.2 to 25.5 Tg CH4 yr−1 for Europe, and by 12.4 Tg CH4 yr−1 for India. The use of the national report to scale EDGAR emissions allows more detailed statistical data and country-specific emission factors to be gathered in place compared to those available for EDGAR inventory. This serves policy needs by evaluating the national or regional emission totals reported to the UNFCCC

Methane Emission Estimates by the Global High-Resolution Inverse Model Using National Inventories

We present a global 0.1° × 0.1° high-resolution inverse model, NIES-TM-FLEXPART-VAR (NTFVAR), and a methane emission evaluation using the Greenhouse Gas Observing Satellite (GOSAT) satellite and ground-based observations from 2010–2012. Prior fluxes contained two variants of anthropogenic emissions, Emissions Database for Global Atmospheric Research (EDGAR) v4.3.2 and adjusted EDGAR v4.3.2 which were scaled to match the country totals by national reports to the United Nations Framework Convention on Climate Change (UNFCCC), augmented by biomass burning emissions from Global Fire Assimilation System (GFASv1.2) and wetlands Vegetation Integrative Simulator for Trace Gases (VISIT). The ratio of the UNFCCC-adjusted global anthropogenic emissions to EDGAR is 98%. This varies by region: 200% in Russia, 84% in China, and 62% in India. By changing prior emissions from EDGAR to UNFCCC-adjusted values, the optimized total emissions increased from 36.2 to 46 Tg CH4 yr−1 for Russia, 12.8 to 14.3 Tg CH4 yr−1 for temperate South America, and 43.2 to 44.9 Tg CH4 yr−1 for contiguous USA, and the values decrease from 54 to 51.3 Tg CH4 yr−1 for China, 26.2 to 25.5 Tg CH4 yr−1 for Europe, and by 12.4 Tg CH4 yr−1 for India. The use of the national report to scale EDGAR emissions allows more detailed statistical data and country-specific emission factors to be gathered in place compared to those available for EDGAR inventory. This serves policy needs by evaluating the national or regional emission totals reported to the UNFCCC