Effects of Local Anesthetics With Vasoconstrictors on Dental Pulp Blood Flow and Oxygen Tension

Objective: The aim of this study was to investigate the changes in pulpal blood flow (PBF) and pulpal oxygen tension (PpulpO2) after injecting local anesthetics with vasoconstrictors. Methods: Under general anesthesia, male Japanese White rabbits were injected with 0.6 mL of 2% lidocaine with 1:80,000 epinephrine (LE) or 3% propitocaine (prilocaine) with 0.03 IU felypressin (PF) at the apical area of the lower incisor. Results: Relative to baseline, PBF and PpulpO2 significantly decreased 5 minutes after LE or PF injection as compared with saline. The decrease in PBF was significantly lower in the LE group than in the PF group. Although the LE group had a larger decrease in PpulpO2 relative to baseline than the PF group did, that difference was not significant. PBF and PpulpO2 recovered to baseline faster in the PF group than in the LE group. Conclusion: The injection of local anesthetic solutions containing vasoconstrictors (LE or PF) transiently caused significant decreases in PBF that resulted in significant decreases in PpulpO2. The recovery of PpulpO2 was faster than PBF regardless of the vasoconstrictor used.

Comparison of Dentinal Tubule Penetration between a Calcium Silicate-Based Sealer with Ultrasonic Activation and an Epoxy Resin-Based Sealer: A Study Using Confocal Laser Scanning Microscopy

Objective The aim of this study was to compare the degree of dentinal penetration between an epoxy resin-based sealer applied by using two different filling methods and an ultrasonically activated calcium silicate-based sealer via confocal laser scanning microscopy (CLSM). Materials and Methods Forty-five extracted permanent maxillary premolars with type II canals (Vertucci’s classification) were subjected to the experiment. The root canals were instrumented and distributed randomly into the following three groups: AH Plus + continuous wave technique (AHC group); AH Plus + single cone technique (AHS group); and Endoseal MTA + single cone technique with ultrasonic activation (EMS) group. Each sealer was labeled with rhodamine B dye to allow visualization under CLSM. The sealer penetration depth in each sample was observed at 2 mm and 5 mm from the apex by using CLSM. The data were statistically analyzed by using analysis of variance or Kruskal–Wallis H test according to normality of variable (α = 0.05). Results In all groups, the maximum sealer penetration depth, mean fluorescence intensity, and sum fluorescence intensity values were higher at the 5-mm level than at the 2-mm level. At the 5-mm level, the EMS group showed the lowest value (p = 0.02). At the 2-mm level, there were no statistically significant differences among any of the groups. The AHC group showed higher values than the other groups, but there was no statistically significant difference in the apical area where access of instruments was difficult. Conclusion The AHC group showed the highest dentinal tubule penetration, but had questionable filing efficacy in the apical area, which is of particular importance for the success of root canal treatment. Therefore, in areas such as the apical 2 mm of premolars with type II canals, which are difficult to access by using instruments such as heat carriers, other appropriate approaches may be required accordingly.

MORPHOMETRIC PATTERNS OF MAXILLAR Y APICAL BASE VARIABILITY IN PEOPLE WITH VARIOUS DENTAL ARCHES AT PHYSIOLOGICAL OCCLUSION

Morphometric data on the structure of the craniofacial complex are reliable and diagnostically significant values that are of applied nature in terms of practical dentistry. Within this study, analysis of conebeam computed tomograms, biometric indicators of plaster models obtained from the jaws of 83 people (aged 21–35) with physiological occlusion and various types of dental, gnathic dental arches, the degree of proportion between the maxillary apical base and the inter-canine distance were identified. Depending on the dental arch type, the patients were divided into three groups. The morphometric study in the CBCT frontal plane was the distance between the canines tearing tubercles and the inter-canine distance in the apical area. The study outcomes revealed discrepancies between the calculated and actual indicators of the apical base width for all types of dental arches in people with physiological occlusion. In case of mesotrusive dental arches (incisional angle — 127–143°), the width of the apical base corresponded to the width of the dental arches between the canines, while the differences in indicators were not statistically significant. In people with retrusive dental arches (incisional angle exceeding 144°), the width of the dental arch was found to be significantly above the width of the apical bases. As far as protrusive dental arches are concerned (incisional angle below 126°), these patients featured predominance of the apical bases width over the inter-canine distance. The obtained data add to that already available in research literature regarding the relationships and dimensional features pertaining to the craniofacial complex structures, as well as have applied value in orthodontic clinical practice

Pacemaker Lead Migration and Ventricular Perforation in a Patient Presenting with Chest Pain

Case Presentation: We describe a middle-age male with a past medical history of second-degree atrioventricular block type II status post permanent pacemaker placement the day prior who presented to the emergency department complaining of chest pain. Electrocardiography showed a non-paced ventricular rhythm. Chest radiograph showed the ventricular pacemaker lead located distally overlying the right ventricle apical area. On further investigation, chest computed tomography showed a perforation of the ventricular wall by the pacemaker lead prompting urgent intervention by the cardiothoracic surgery team for lead replacement and right ventricular repair. Discussion: Our case illustrates the importance of timely recognition of a perforated pacemaker lead in a patient presenting with chest pain after device implantation. We additionally describe the risk factors for ventricular perforation, initial clinical presentation, and management approach.

Counterclockwise Drilling with Different Tapered Drills Condenses the Implant Bed—An Optical Coherence Tomography In Vitro Study

Background and Objectives: To evaluate the condensation and the microarchitecture of implant bed walls of sites prepared with counterclockwise drilling with tapered implant drills using optical coherence tomography. Materials and Methods: Four drill designs with different wall and tip angles were used. Polyurethane laminas resembling type IV bone microarchitecture were superimposed and clamped with a vice to simulate the coronal, middle, and apical aspects of the implant site. Twenty implant beds were prepared at 1200 rpm in clockwise (control) and counterclockwise (test) directions (N = 160). Optical coherence tomography (OCT) was used to evaluate the condensation and microarchitecture characteristics of the implant bed walls. The relative condensation was calculated using the Image J software Bone application. The microarchitecture was evaluated in reconstructed 3D volumes in XY, XZ, and YZ sections. Statistical analysis was performed using one-way ANOVA. Dunnet test was applied to determine differences between groups. Significance was set as p < 0.05. Results: Counterclockwise drilling (Test) condensed and changed the microarchitecture of the apical regions for all the implant beds in all of the groups when compared to clockwise drilling (control). The apical region of test groups showed the highest relative bone condensation (p = 0.026) when compared to controls. Conclusions: The direction of rotation (counterclockwise drilling) and not the design of tapered drills (tip and wall angles) is responsible for the condensation at the apical area observed in polyurethane blocks. The OCT method can be used for the evaluation of changes in density and microstructure of polyurethane blocks.

Revision of the genera Habetia Kirby, 1906 and Parahabetia gen. nov. from New Guinea (Orthoptera, Tettigoniidae, Conocephalinae, Agraeciini)

The genus Habetia Kirby, 1906 previously known from only four species or subspecies is revised based on unidentified specimens found in museum collections. H. multispinulosa Griffini, 1908 is given full species status, while H. pictifrons Karny, 1911 is removed from Habetia based on male and female characters and becomes the type species of the new genus Parahabetia gen. nov. Sixteen new species are described in Habetia, and one new species and two new subspecies in Parahabetia. The most significant characters for the differentiation of species of Habetia are male tenth abdominal tergite, cerci, subgenital plate, and male internal genitalia with the titillators that basically form a pair of roughly U-shaped sclerites that vary between species from simple, curved sclerites to modified structures with additional sclerotized branches and the sclerites can be connected with septa to form complex shapes. In contrast, males of Parahabetia have elongate titillators provided at end with a crest. In the larger species of Habetia the stridulatory file on the underside of the male left tegmen has a step in pre-apical area that is missing in the smaller species; one species with a weak step is intermediate between both groups. Unique modifications of single species in Habetia are an apical dorsal extension of the male subgenital plate in H. imitatrix Karny, 1912 and a hardened phallus sheath between phallus and subgenital plate in H. tuta sp. nov. Females of Habetia have straight ovipositors that vary in length and in the shape of the dorsal margin between species. Females can also be differentiated by species specific modifications of the subgenital plate. In Parahabetia the ovipositor is rather short and curved similar to the condition in the genus Philmontis Willemse, 1966 but has the apical area slightly recurved. Keys to the species of both genera are provided. Habetia species have been found throughout New Guinea except so far for Papua Barat; although they were mainly found in the North and the East. Parahabetia species are currently only known from the East of New Guinea. The following species and subspecies are described as new: Habetia bivittata sp. nov., H. curvata sp. nov., H. dentata sp. nov., H. elevata sp. nov., H. kondiu sp. nov., H. lalibu sp. nov., H. nigricauda sp. nov., H. pallida sp. nov., H. pedala sp. nov., H. pilleata sp. nov., H. pinnigera sp. nov., H. quatrispina sp. nov., H. simbai sp. nov., H. sororcula sp. nov., H. tuta sp. nov., H. wau sp. nov., Parahabetia bispinosa sp. nov., P. pictifrons obtusa ssp. nov., P. pictifrons acuta ssp. nov.

Takotsubo syndrome following pericardiectomy

Background: Takotsubo cardiomyopathy (TC) is defined as a temporary and reversible systolic abnormality of the left ventricle’s apical area resembling myocardial infarction (MI) in the nonexistence of coronary artery disease (CAD)[1].Only a few cases have been reported after cardiac operations or after pericardiocentesis. Aims: To emphasize the need to be aware of the possibility of the occurrence of this potentially fatal complication after cardiac surgery. Materials and methods: A-66-year old man underwent pericardiectomy.Postoperative he endured TC and progressed exacerbation of hemodynamic instability.finally, he had to be supported by intra-aortic balloon pump（IABP),extracorporeal membrane oxygenation（ECMO). Results: Patient’s left ventricle function recovered fully in two weeks. Discussion: we discussed the pathogenesis and treatment of postoperative TC. Conclusion:TC has to be carefully considered in differential diagnosis in case of acute left ventricle dysfunction following cardiac surgery. Keywords: pericardiectomy; takotsubo cardiomyopathy.

Volume Percentage of Filling Voids in Root Canals Prepared by a Novel Nickel-Titanium Rotary System (TruNatomy) Using Two Different Obturation Techniques

This study aimed to compare the volume percentage of filling voids in root canals prepared with a newly introduced rotary system, TruNatomy (Dentsply Maillefer), and obturated by the modified continuous wave (CW) or single cone (SC) filling technique. Plastic tooth models with four canals were enlarged by using TruNatomy files and randomly allocated into either the CW or SC group. The volume percentage of filling voids at 1–6 mm from the apex was analyzed by using microcomputed tomography; mean values were compared by using independent two-sample t-tests (p < 0.05). The mean volume percentages of the filling voids were 2.81 ± 1.11% and 1.77 ± 0.82% in the CW and SC groups, respectively. In the apical area (1–4 mm), volume percentages in the palatal were significantly different between the CW and SC groups; in the middle area (4–6 mm), volume percentages in the palatal and mesiobuccal 2 canals were significantly different (p < 0.05). The SC group showed lower volume percentages of filling voids than the CW group. The canals prepared by the TruNatomy system can be obturated well by both the SC and CW techniques. The SC technique showed a lower number of voids, especially in the palatal canals.

Mechanical stretch scales centriole number to apical area via Piezo1 in multiciliated cells

How cells count and regulate organelle number is a fundamental question in cell biology. For example, most cells restrict centrioles to two in number and assemble one cilium; however, multiciliated cells (MCCs) synthesize hundreds of centrioles to assemble multiple cilia. Aberration in centriole/cilia number impairs MCC function and can lead to pathological outcomes. Yet how MCCs control centriole number remains unknown. Using Xenopus, we demonstrate that centriole number scales with apical area over a remarkable 40-fold change in size. We find that tensile forces that shape the apical area also trigger centriole amplification based on both cell stretching experiments and disruption of embryonic elongation. Unexpectedly, Piezo1, a mechanosensitive ion channel, localizes near each centriole suggesting a potential role in centriole amplification. Indeed, depletion of Piezo1 affects centriole amplification and disrupts its correlation with the apical area in a tension dependent manner. Thus, mechanical forces calibrate cilia/centriole number to the MCC apical area via Piezo1. Our results provide new perspectives to study organelle number control essential for optimal cell function.

Prevalence of Missed Canals and Their Association with Apical Periodontitis in Posterior Endodontically Treated Teeth: A CBCT Study

Background. This study aimed to assess the prevalence of missed canals in endodontically treated teeth and their association with apical periodontitis in a Saudi Arabian population using CBCT. Materials and Methods. A total of 208 CBCT radiographs were investigated. For each tooth, radiographs of axial, coronal, and sagittal segments were acquired to appraise the external as well as the internal structure of the root canal system and apical area. In root canal-treated teeth, unfilled canals appearing from the cementoenamel junction to the apex were defined as missed untreated canals; and a periapical lesion was considered when disruption of the lamina dura was detected, and the low-density area associated with the radiographic apex was at least twice the width of the periodontal ligament space. The data were presented as frequencies and percentages. The Z-test was used to analyze the differences in proportions with the significance level set at P value <0.05. Results. The overall prevalence of missed canals among endodontically treated teeth was 18%. The prevalence of missed canals was higher in maxillary first molars with 40.6%. The overall prevalence of apical periodontitis among teeth with missed canals was 90%. It was 84.2% in the maxilla and 100% in the mandible. The second mesiobuccal canal in the maxillary first molars and mesiobuccal and distobuccal canals in mandibular teeth were the most missed canals. Conclusion. Apical periodontitis in root canal-treated teeth with missed canals was high (90%), with most identified missed canals in maxillary and mandibular first molars.