Johnson City Research Articles

Dr. Frederick H. Kasten 1927 – 2014

Dr. Frederick H. (Fred) Kasten, 87, Johnson City, Tennessee, died Monday, April 14, 2014 at the Johnson City Medical Center following a lengthy illness. The son of the late Isaac Kasten and Anna Go...

Investigation of a novel mechanically mixed mineral trioxide aggregate (MM-MTA(™) ).

To characterize a novel mechanically mixed mineral trioxide aggregate product (MM-MTA, MicroMega, Besançon, France) and to investigate the physical and chemical properties in comparison with ProRoot MTA (Dentsply, Tulsa Dental, Johnson City, TN, USA) and MTA Angelus (Angelus, Londrina, Brazil). The three materials were mixed according to manufacturer's instructions. Specimens 10mm in diameter and 2mm high were prepared and characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD) analysis after 1-day and 28-day storage in physiological solution. Calcium ion leaching in solution and pH of the elution were also assessed. Furthermore, the setting time, radiopacity and material porosity were investigated. Statistical analysis was performed by anova and Tukey's post hoc tests. All the MTAs tested were composed primarily of tricalcium silicate and bismuth oxide. In addition, MM-MTA exhibited additional peaks for chlorine evident in the EDS analysis; calcium carbonate was present in the set material detected by XRD. Calcium hydroxide was present in the set ProRoot MTA and MTA Angelus. Calcium ion leaching and alkalization of the storage solution were demonstrated in all the materials. Both MM-MTA and MTA Angelus had a shorter setting time when compared to ProRoot MTA (P<0.001). ProRoot MTA exhibited larger pores and more porosity than MTA Angelus and MM-MTA. All the materials exhibited radiopacity greater than the 3mm aluminium thickness specified in ISO 6876 (2012). MM-MTA, ProRoot MTA and MTA Angelus are composed of Portland cement and bismuth oxide. In addition, MM-MTA contains calcium carbonate and a chloride accelerator. These additives affect the material hydration and the properties of the set material. The properties of MM-MTA are a result of a combination of factors, namely the particular cement mineralogy, radiopacifier loading, effective water-cement ratio and mechanical mixing.

Blackwelder and Cross collaborate in family medicine clinic

When Brian Cross, PharmD, first went to work for the Indian Health Service (IHS) on the San Carlos Apache Reservation in eastern Arizona in 1991, he believed that the physician-pharmacist collaboration that he encountered there—a model pioneered by the IHS and a handful of other federal agencies and private health care systems—as common across the country.

Molecular Twist of an Innocent Leukocytosis: “Dream or Dread” for a Clinician

Debalina Das1, Elizabeth Arze2, Elnora Spradling1, Chad King2, Devapiran Jaishankar1 and Kanishka Chakraborty1* 1Department of Internal Medicine, Quillen College of Medicine, East Tennessee State University, USA 2Department of Pathology, Quillen College of Medicine, East Tennessee State University, USA *Corresponding author: Kanishka Chakraborty, Assistant Professor, East Tennessee State University-Quillen, College of Medicine, Internal Medicine, JOHNSON CITY, Tennessee 37604, USA, Tel: 4232326979; E-mail: chakrabk@etsu.edu

Root Canal Preparation of Mandibular Molars with 3 Nickel-Titanium Rotary Instruments: A Micro–Computed Tomographic Study

IntroductionThe aim of this study was to describe the canal shaping properties of ProTaper Next (PTN; Dentsply Maillefer, Ballaigues, Switzerland), ProTaper Universal (PTU; Dentsply Tulsa Dental Specialties, Johnson City, TN), and WaveOne (Dentsply Maillefer) nickel-titanium instruments in mandibular first molars by using micro–computed tomographic (micro-CT) scanning. MethodsA total of 36 maxillary first molars with 2 separate mesial canals and 1 distal canal were selected and scanned preoperatively and postoperatively by using micro-CT scanning with a voxel size of 30 μm. Canals were prepared with PTU, PTN, and WaveOne systems under hypochlorite irrigation. The volume of the untreated canal; the volume of dentin removed after preparation; the amount of the uninstrumented area; and the transportation to the coronal, middle, and apical thirds of canals were measured. The preparation time and instrument failure were also recorded. ResultsInstrumentation of canals increased their volume and surface area. The distal canals had a significantly higher proportion of unprepared surfaces than mesial canals (P < .05). The PTN system produced less transportation than the WaveOne and PTU systems in the apical third of the mesial canals (P < .05). There was no significant difference on apical transportation in distal canals among the 3 instrument systems. Instrumentation with WaveOne was significantly faster than with the other 2 instruments (P < .05). ConclusionsThe PTN, PTU, and WaveOne instruments shaped root canals in mandibular first molars in vitro without significant shaping errors. The curved canals prepared using PTN had less apical transportation than the canals prepared using WaveOne and PTU.

Implementation of the Academy of Nutrition and Dietetics Foundation’s RD Parent Empowerment Program at Johnson City Head Start Centers by East Tennessee State University Dietetic Interns

Implementation of the Academy of Nutrition and Dietetics Foundation’s RD Parent Empowerment Program at Johnson City Head Start Centers by East Tennessee State University Dietetic Interns

Acidic pH weakens the microhardness and microstructure of three tricalcium silicate materials.

To investigate the microhardness and microstructural features of three tricalcium silicate materials: mineral trioxide aggregate (MTA), Endosequence Root Repair Material Putty (ERRM Putty) and Endosequence Root Repair Material Paste (ERRM Paste), after exposure to a range of acidic environments in comparison with intermediate restorative material (IRM). Endosequence Root Repair Material Putty (Brasseler, Savannah, GA, USA), ERRM Paste (Brasseler, Savannah, GA, USA), MTA (ProRoot; Dentsply Tulsa Dental, Johnson City, TN, USA) and IRM (Dentsply Caulk, Milford, DE, USA) were set in cylindrical rubber moulds as four groups containing twenty specimens each. Fifteen specimens per each material were randomly distributed into three groups (n=5) to be exposed to butyric acid buffered at three different pH levels (5.4, 6.4 and 7.4) for 7days. The remaining five specimens were exposed to distilled water as a control group. The surface microhardness after exposure either to acid or to water was measured after 7-days at 37°C. The morphology of the internal microstructure was observed using a scanning electron microscope (SEM). Two-way univariate analysis of variance (anova) was applied to evaluate the Vickers microhardness value (VHN). The microhardness values of the materials were significantly higher in the neutral environment of butyric acid at pH 7.4 compared to those in the acidic condition of pH 5.4 for all groups (P<0.001). MTA, ERRM Putty and ERRM Paste had higher microhardness values than IRM at all pH levels (P<0.001). Specimens exposed to distilled water displayed significantly higher microhardness values than those values obtained in the presence of butyric acid buffered to all pH levels (P<0.001). A more porous microstructure was observed following exposure to butyric acid at pH 5.4 than at pH 7.4. Several types of crystalline structures were formed by recrystallization, especially at pH 7.4 in all groups except for IRM. The microhardness values of ERRM Putty, ERRM Paste and MTA were reduced in an acidic environment, which resulted in these materials having more porous and less crystalline microstructures. MTA seems the most suitable material for application to an area of inflammation where a low pH value may exist.

Vitamin D insufficiency/deficiency management.

In recent years, vitamin D deficiency has been recognized increasingly often in patients, and different supplement regimens have been prescribed to treat it. There has been no consensus on treatment regimens. This study was conducted to determine the management of vitamin D deficiency/insufficiency in outpatient adults in northeast Tennessee. A retrospective record review was conducted in an internal medicine teaching clinic for patients seen from July 2007-July 2008 in Johnson City, Tennessee. A total of 626 nonelectronic charts listed with vitamin D measurements were used in the analysis. Data regarding the level of vitamin D, whether treatment was prescribed, dose and duration of treatment prescribed, and repeat levels of vitamin D, if any were ordered, were collected. Vitamin D deficiency was defined as levels <20 ng/mL; vitamin D insufficiency was defined as levels ranging from 20 to 29.9 ng/mL. Of the 626 patients, 325 (52%) were vitamin D deficient or insufficient. Of these 325 patients, 184 were given a low-dose supplement and 54 received a high-dose supplement. Eighty-seven were either not prescribed any replacement or the dose was unknown (not documented in the chart). The mean change in serum vitamin D levels was significantly different for the high dose compared with the low dose prescribed. There was no significant sex difference in response to the dose given. On average, those who were vitamin D deficient experienced a greater change than those who were insufficient and a greater change, on average, was observed in those who received a higher dose. Vitamin D deficiency and insufficiency are highly prevalent. Clinicians tended to prescribe a high dose of treatment for lower levels of serum vitamin D. The response is higher in high-dose treatment. Documentation regarding whether vitamin D supplements were given or the dose of supplements was given and followed up with repeat levels of vitamin D after treatment was poor.

Evaluation of Compressive Strength of Hydraulic Silicate-based Root-end Filling Materials

IntroductionHydraulic silicate cements such as mineral trioxide aggregate (MTA) have many clinical advantages. Newer hydraulic silicate materials have been developed that improve on the limitations of mineral trioxide aggregate such as the long setting time and difficult handling characteristics. The purpose of this study was to examine the effect of saline and fetal bovine serum (FBS) on the setting and compressive strength of the following hydraulic silicate cements: ProRoot MTA (white WMTA; Dentsply International, Tulsa Dental Specialties, Johnson City, TN), EndoSequence Root Repair Material (Brasseler USA, Savannah, GA), MTA Plus (MTAP; Avalon Biomed Inc, Bradenton, FL), and QuickSet (QS; Avalon Biomed Inc, Bradenton, FL). MethodsSamples of root-end filling materials were compacted into polyethylene molds. Samples were exposed to FBS or saline for 7 days. A universal testing machine was used to determine the compressive strengths. ResultsQS had significantly lower compressive strength than all other materials (P < .001). White MTA and MTAP mixed with liquid had lower compressive strengths after exposure to FBS compared with saline (P = .003). ERRM, MTAP mixed with gel, and QS were not affected by the exposure to FBS. ConclusionsNew silicate-based root-end filling materials, other than QS, have compressive strength similar to MTA. Within the limits of this study, premixed materials and those mixed with antiwashout gel maintain their compressive strength when exposed to biological fluids.

To Evaluate and Compare Effect of Calcium Hydroxide with Different Vehicles on the Mineral Content of Root Dentin: An EDAX Analysis

ABSTRACT Introduction The aim of this study is to evaluate and compare effect of calcium hydroxide with different vehicles on the mineral content of root dentin—an EDAX analysis, after 1, 2 and 3 weeks. Materials and methods Seventy-five freshly extracted single rooted teeth were selected for study and randomly divided into 5 groups. An access to the root canal of all teeth was prepared using a round and cylindrical bur (Mani Inc.). Canals were instrumented with stainless steel K file (Dentsply Maillefer, Johnson City, TN) so that the file extended beyond the apical foramen by 1 mm. And then canals were prepared to a size F2 with hand proTaper (Dentsply Maillefer, Johnson City, TN). Copious irrigation with sterile saline was done. Sample of group 1—were sealed apically with bonded composite resin and coronally with cotton pellet and bonded composite resin. Samples of group 2—were filled with thick slurry made with calcium hydroxide and saline using lentulo spiral (Henry Schein). To ensure intimate contact with the canal walls, excess calcium hydroxide was intentionally extruded past the apex. Root canals were sealed apically and coronally in the same manner as in previous group. Samples of group 3—Calcigel (water based calcium hydroxide, Prevest Denpro Ltd), group 4—Metapex (oil based calcium hydroxide, Meta BioMed) and group 5—Calcium hydroxide and propylene glycol, were prepared in the same manner as previous group. The samples were maintained at room temperature and 100% humidity in incubator. After 7 days, 5 samples from each group were removed from incubator and the roots were vertically sectioned into 1 mm thick specimen with water cooled diamond disk. Each section of sample was then evaluated under EDAX. After 14th and 21st day 5 samples of each group were removed and tested in same manner as mentioned previously. How to cite this article Bagmar S, Jadhav S, Hegde V, Dixit V, Shiraguppi VKL. To Evaluate and Compare Effect of Calcium Hydroxide with Different Vehicles on the Mineral Content of Root Dentin: An EDAX Analysis. World J Dent 2014;5(3):170-173.

Perception and Steering Control in Paired Bat Flight

Animals within groups need to coordinate their reactions to perceived environmental features and to each other in order to safely move from one point to another. This paper extends our previously published work on the flight patterns of Myotis velifer that have been observed in a habitat near Johnson City, Texas. Each evening, these bats emerge from a cave in sequences of small groups that typically contain no more than three or four individuals, and they thus provide ideal subjects for studying leader-follower behaviors. By analyzing the flight paths of a group of M. velifer, the data show that the flight behavior of a follower bat is influenced by the flight behavior of a leader bat in a way that is not well explained by existing pursuit laws, such as classical pursuit, constant bearing and motion camouflage. Thus we propose an alternative steering law based on virtual loom, a concept we introduce to capture the geometrical configuration of the leader-follower pair. It is shown that this law may be integrated with our previously proposed vision-enabled steering laws to synthesize trajectories, the statistics of which fit with those of the bats in our data set. The results suggest that bats use perceived information of both the environment and their neighbors for navigation.

Direct pulp capping using biodentine

Introduction. Direct pulp capping is therapeutic method of applying medication on exposed pulp in order to allow bridge formation and healing process. The aim of this study was to investigate the effect of Biodentine on exposed dental pulp of Vietnamese pigs. Material and Methods. The study was conducted on 20 teeth of Vietnamese pigs (Sus scrofa domesticus). On buccal surfaces of incisors, canines and first premolars, class V cavities were prepared and pulp was exposed. In the experimental group (six incisors, two canines and two premolars) the perforation was covered with Biodentine? (Septodont, Saint-Maur-des-Fosses, France). In the control group, the perforation was covered with MTA? (Dentsply Tulsa Dental, Johnson City, TN, USA). All cavities were restored with glass ionomer cement (GC Fuji VIII, GC Corporation, Tokyo, Japan). Observation period was 28 days. After sacrificing the animals, histological preparations were done to analyze the presence of dentin bridge, an inflammatory reaction of the pulp, pulp tissue reorganization and the presence of bacteria. Results. Dentin bridge was observed in all teeth (experimental and control groups). Inflammation of the pulp was mild to moderate in both groups. Neoangiogenesis and many odontoblast like cells responsible for dentin bridge formation were detected. Necrosis was not observed in any case, neither the presence of Gram-positive bacteria in the pulp. Conclusion. Histological analysis indicated favorable therapeutic effects of Biodentine for direct pulp capping in teeth of Vietnamese pigs. Findings were similar with Biodentine and MTA.

Effect of Acid Etching Procedures on the Compressive Strength of 4 Calcium Silicate–based Endodontic Cements

IntroductionThe purpose of this study was to evaluate the effect of acid etching on the compressive strength of 4 calcium silicate–based cements. MethodsOne gram of each corresponding powder of ProRoot MTA (Dentsply Tulsa Dental, Johnson City, TN), MTA Angelus (Angelus, Londrina, PR, Brazil), and CEM cement (BioniqueDent, Tehran, Iran) and a 0.33-g aliquot of liquid were placed in a plastic mixing capsule that was then mechanically mixed for 30 seconds at 4500 rpm in an amalgamator. For the preparation of Biodentine (Septodont, Saint Maur-des-Fossés, France), the liquid provided was added to the powder within the plastic capsule supplied by the manufacturer and then mechanically mixed for 30 seconds at 4500 rpm using the amalgamator. The resulting slurries were then placed incrementally into 40 cylindrical molds to give a total of 160 specimens that were incubated at 37°C for a week. Twenty specimens of each material were then subjected to the acid etch procedure. The compressive strength of the samples was then calculated in megapascals using a universal testing machine. The results were then subjected to 2-way analysis of variance analysis of variance followed by the Tukey post hoc test. ResultsThe application of acid etch significantly reduced (P < .0001) the compressive strength of Angelus MTA and CEM cement; however, it did not reduce the compressive strength of ProRoot MTA or Biodentine. Regardless of the acid etch application, Biodentine showed significantly higher compressive strength values than the other materials (P < .0001), whereas CEM cement had the lowest compressive strength values. There was no significant difference between CEM cement and MTA Angelus. The compressive strength of ProRoot MTA was significantly lower (P < .0001) than Biodentine but significantly higher (P < .0001) than MTA Angelus and CEM cement in both the test and control groups. ConclusionsWhen the application of acid etchants is required, Biodentine and ProRoot MTA seem to be better options than MTA Angelus or CEM cement.

Failed species, innominate forms, and the vain search for species limits: cryptic diversity in dusky salamanders (Desmognathus) of eastern Tennessee

AbstractCytochrome B sequences and allozymes reveal complex patterns of molecular variation in dusky salamander (Desmognathus) populations in eastern Tennessee. One group of allozymically distinctive populations, which we refer to as the Sinking Creek form (SCF), combines morphological attributes of Desmognathus fuscus with cytB sequences characteristic of Desmognathus carolinensis. This form is abruptly replaced by D. fuscus just north of Johnson City, TN with no evidence of either sympatry or gene exchange. To the south, allozymic markers indicate a broad zone of admixture with populations characterized by distinct cytB sequences and that may or may not be ultimately referable to Desmognathus conanti. A third distinctive group of populations, which we refer to as the Lemon Gap form (LGF), occurs in the foothills of the Great Smoky and southern Bald Mountains and exchanges genes with Desmognathus santeetlah along the escarpment of the Great Smokies, D. carolinensis in the southern Bald Mountains, and populations of a different haplotype clade in the Ridge and Valley. We treat all these as innominate forms that may represent “failed species,” recognizing that it may never be possible to reconcile species limits with patterns of phylogeny, morphology, and gene exchange in these salamanders.

The pharmacist’s personal IMPACT

At all of the diverse Project IMPACT: Diabetes sites, pharmacists are having firsthand experience with the effectiveness of personal contact with patients. By encouraging patients to adhere to their medications, helping them navigate the tricky waters of the health care system, or simply listening to their concerns, pharmacists can make a difference just by their presence.

The setting characteristics of MTA Plus in different environmental conditions

Characterization and assessment of the hydration reaction of mineral trioxide aggregate (MTA) Plus exposed to different environmental conditions. The specific surface area, surface morphology and characterization of un-hydrated MTA Plus (Avalon Biomed Inc. Bradenton, FL, USA) were investigated. The specific surface area was compared with that of ProRoot MTA (Dentsply International, Tulsa Dental Specialties, Johnson City, TN, USA). The reaction rate was determined using calorimetry, and the hydrated cement was assessed for setting time (determined using an indentation technique), and the set material was characterized using X-ray diffraction analysis, scanning electron microscopy and X-ray energy-dispersive analysis. Atomic ratio plots were drawn to establish the relationship of the hydration products. Three different environmental conditions namely dry or immersed in either water or Hank's balanced salt solution (HBSS) were used. Mineral trioxide aggregate Plus had a higher specific surface area than ProRoot MTA. The hydration reaction was exothermic. The setting time of MTA Plus was retarded when in contact with fluids (P<0.001). The setting time was longer when MTA Plus was in contact with HBSS than when in contact with water (P<0.001). Hydration of MTA Plus resulted in the formation of calcium silicate hydrate, calcium hydroxide, ettringite and monosulfate phases. Bismuth was incorporated in the calcium silicate hydrate structure. The hydration of the core material was not affected by contact with the different solutions but the periphery exhibited microcracking, leaching of calcium hydroxide, partial decalcification of calcium silicate hydrate, inhibition of hydration in contact with the physiological solution. The novel MTA Plus was finer than ProRoot MTA but had a similar chemical composition. MTA Plus in direct contact with fluids exhibited partial decalcification of calcium silicate hydrate in contact with the solution, microcracking and leaching of calcium hydroxide. Interaction with a physiological solution resulted in inhibition of hydration.

The Making of a Historic District and the Economic Impact upon Housing Value: An Empirical Analysis of the Tree Streets Neighborhood in Johnson City, Tennessee

Many urban communities in the United States faced deteriorating physical infrastructure and social environment in the second half of the 20th century. To restore such inner city neighborhoods, many neighborhoods have adopted historic preservation as a means to both aesthetically and fiscally improve the condition. This paper studies a historic district in the Tree Streets neighborhood, Johnson City, Tennessee in regard to its road toward historical preservation and neighborhood restoration. We find that through decades of a local civic organization’s efforts and government planning initiatives, the community has successfully turned from a university slum into a livable neighborhood. We also find that the benefits are not strictly nostalgic but there is a positive economic impact of historic preservation designation on property values. The making of the historic district in the Tree Streets neighborhood both socially and economically has provided a great example of smart growth for Johnson city and other American cities to revitalize urban residential neighborhoods in central cities.

Combating Childhood Obesity through a Young Adult-Led S.O.C.C.E.R. Program in Northeast Tennessee

In January 2012, a Youth Service America UnitedHealth Heroes-funded service-learning program focused on instilling healthy behaviors among children in Johnson City, Tennessee. The program, S.O.C.C.E.R. (Stopping Childhood Obesity in Children through Creative Education and Reinforcement), was implemented by various East Tennessee State University student-affiliated groups including Athletics, College of Public Health, and Allied Health Sciences/ Pre-medicine. Staff from the Boys and Girls Club and the university helped to guide student volunteers in the implementation of the program. Participation in program activities such as playing soccer increased children's knowledge of healthy lifestyle habits and provided an opportunity for the young adult-volunteers to hone their leadership skills. Ongoing federally funded research around the efficacy of peer-to-peer related intervention is currently underway.

Shaping Ability of Three Nickel-Titanium Endodontic File Systems in Simulated S-shaped Root Canals

IntroductionThe purpose of this study was to determine the shaping ability of 3 nickel-titanium (NiTi) endodontic file systems by measuring canal transportation. MethodsSeventy-two S-shaped canals in resin blocks were randomly allocated into 3 groups (n = 24): the Self-Adjusting File (SAF; ReDent Nova, Ra’anana, Israel) group, the Typhoon group (Typhoon rotary files with Controlled Memory Wire; DS Dental, Johnson City, TN), and the Vortex group (ProFile Vortex rotary files with M-Wire NiTi; Dentsply Tulsa Dental Specialties, Tulsa, OK). Blocks were secured in a jig for imaging standardization and instrumentation stabilization. Gates Glidden and PathFile drills (25 mm/.02 taper) were used to prepare the glide paths. For the Typhoon and Vortex groups (25 mm/.04 taper), canals were flooded with sterile water and instrumented using a crown-down technique from sizes 40 to 20/.04 and then apically enlarged to size 30/.04. The SAF group (25 mm) was instrumented with constant sterile water irrigation in a light-pecking, transline motion. Pre- and postinstrumentation images were taken at 40× magnification and layered, and canal transportation was measured. ResultsAfter adjusting for the level and canal wall side, the mean transportation was significantly higher for the Typhoon (P < .001) and Vortex (P = .005) groups compared with the SAF group. Additionally, the mean transportation was significantly higher for the Typhoon group versus the Vortex group (P < .001). ConclusionsUnder the conditions of this study, SAFs showed less canal transportation than ProFile Vortex and Typhoon files in simulated S-shaped root canals.

Vitamin D deficiency: A potential risk factor for Clostridium difficile infection

Vitamin D deficiency: A potential risk factor for Clostridium difficile infection Dima Youssef,1 William B Grant,2 Alan N Peiris3,41Department of Internal Medicine, Division of Infectious Diseases, 2Sunlight, Nutrition and Health Research Center, San Francisco, CA USA; 3Department of Medicine, Mountain Home VAMC, 4Department of Medicine, East Tennessee State University, Johnson City, Tennessee, USA In the July 3, 2012 issue of the journal of Risk Management and Healthcare Policy, Martinez et al present a nice review on Clostridium difficile (C. difficile) infections.1 The different manifestations of this challenging disease along with the high cost and burden on the health care system were discussed. While the authors did an admirable job in discussing traditional risk factors, they do not mention vitamin D deficiency.View original paper by Martinez and colleagues.