Current trends in pulp therapy: a survey analyzing pulpotomy techniques taught in pediatric dental residency programs.

Purpose: The study's purpose was to survey directors of pediatric dental residency programs in order to evaluate the materials currently being taught and used for pulpotomy procedures for primary teeth in educational and clinical settings.

Methods: A web-based survey was emailed to all graduate pediatric dental residency program directors in the United States.

Results: Seventy one emails were sent to program directors, 47 responded but only 39 respondents (55%) were included in the study.

Kinetics of Bacillus cereus spore inactivation in cooked rice by combined pressure-heat treatment.

The efficacy of pressure-heat treatment was evaluated for the inactivation of Bacillus cereus spores in cooked rice. The spores of B. cereus ATCC 9818 were inoculated (1.

Modeling time to inactivation of Listeria monocytogenes in response to high pressure, sodium chloride, and sodium lactate.

A mathematical model was developed to predict time to inactivation (TTI) by high pressure processing of Listeria monocytogenes in a broth system (pH 6.3) as a function of pressure (450 to 700 MPa), inoculum level (2 to 6 log CFU/ml), sodium chloride (1 or 2%), and sodium lactate (0 or 2.5%) from a 4°C initial temperature.

Comparison of rotary instrumentation and continuous wave obturation to reciprocating instrumentation and single cone obturation with a hydrophilic sealer.

This in vitro study compared the effectiveness between ProFile 29 Series rotary system followed by continuous wave obturation and the Endo-Eze system. Thirty-six human mandibular canine and premolar teeth were randomly separated into 2 groups of 18. Each tooth was embedded in resin and sectioned at 2, 6, and 12 mm from the apex and viewed under the scanning electron microscope at 50-150x magnification.

An in vitro comparison of microleakage between Resilon and gutta-percha with a fluid filtration model.

This investigation compared microleakage of teeth obturated with gutta-percha and teeth obturated with Resilon by using a fluid filtration model. Forty-six human, single-rooted, mandibular premolars were studied. Teeth were randomly assigned to 2 experimental groups of 21 teeth each, designated as group G (gutta-percha) and group R (Resilon).

An in vitro evaluation of the contents of root canals obturated with gutta percha and AH-26 sealer or Resilon and Epiphany sealer.

The purpose of this study was to compare the contents of root canals obturated with gutta percha and AH-26 sealer (Dentsply, Tulsa, OK) to canals obturated with the Resilon and Epiphany (Pentron, Wallingford, CT) system. Canal contents were assessed by determining the percentage of canal space occupied by core material, sealer, voids, and debris. Forty extracted human maxillary anterior teeth were instrumented, and the teeth were randomly assigned to either the gutta percha/AH 26 group or the Epiphany/Resilon group.

Solute-specific effects of osmotic stress on Staphylococcus aureus.

Aim: To determine if cell death from osmotic stress is because of lack of sufficient energy to maintain cell metabolism. Additionally, the solute-specific effect of five humectants on bacterial osmoregulation and cell survival was examined.

Methods And Results: Staphylococcus aureus was placed into 84% relative humidity (RH) broth (five humectants used individually).

Modeling the growth boundary of Listeria monocytogenes in ready-to-eat cooked meat products as a function of the product salt, moisture, potassium lactate, and sodium diacetate concentrations.

A central composite response surface design was used to determine the time to growth of Listeria monocytogenes as a function of four continuous variables: added sodium chloride (0.8 to 3.6%), sodium diacetate (0 to 0.

Staphylococcus aureus growth boundaries: moving towards mechanistic predictive models based on solute-specific effects.

The formulation of shelf-stable intermediate-moisture products is a critical food safety issue. Therefore, knowing the precise boundary for the growth-no-growth interface of Staphylococcus aureus is necessary for food safety risk assessment. This study was designed to examine the effects of various humectants and to produce growth boundary models as tools for risk assessment.

An immunohistochemical study of osteoprotegerin in the human dental pulp.

This study investigated the expression of osteoprotegerin (OPG) in healthy and inflamed dental pulps. Histological sections 7 microm thick of 47 teeth, either caries-free or affected by gross caries, were used. Sections were stained with hematoxylin-eosin, and other sections of the same specimen were subjected to the avidin-biotin peroxidase complex immunohistochemical procedure for detection of OPG.

Improving recovery of Salmonella enterica serovar typhimurium DT104 cells injured by heating at different water activity values.

This study describes the evaluation of potentially more sensitive methods for the recovery of Salmonella cells injured by heating (54 to 60 degrees C) at different water activity values (0.65 to 0.90, reduced using equal portions of glucose and fructose).

Effect of challenge temperature and solute type on heat tolerance of Salmonella serovars at low water activity.

Salmonella spp. are reported to have an increased heat tolerance at low water activity (a(w); measured by relative vapor pressure [rvp]), achieved either by drying or by incorporating solutes. Much of the published data, however, cover only a narrow treatment range and have been analyzed by assuming first-order death kinetics.

Calculating Salmonella inactivation in nonisothermal heat treatments from isothermal nonlinear survival curves.

Salmonella cells in two sugar-rich media were heat treated at various constant temperatures in the range of 55 to 80 degrees C and their survival ratios determined at various time intervals. The resulting nonlinear semilogarithmic survival curves are described by the model log10S(t) = -b(T)tn(T), where S(t) is the momentary survival ratio N(t)/N0, and b(T) and n(T) are coefficients whose temperature dependence is described by two empirical mathematical models. When the temperature profile, T(t), of a nonisothermal heat treatment can also be expressed algebraically, b(T) and n(T) can be transformed into a function of time, i.

Modeling the growth boundary of Staphylococcus aureus for risk assessment purposes.

Knowing the precise boundary for growth of Staphylococcus aureus is critical for food safety risk assessment, especially in the formulation of safe, shelf-stable foods with intermediate relative humidity (RH) values. To date, most studies and resulting models have led to the presumption that S. aureus is osmotolerant.

Instrumentation enhances today's endodontic care.

The field of endodontics has virtually exploded in the last several years with technological advances and improvements in many areas. The largest change has occurred with the introduction of nickel-titanium rotary instrumentation, warm gutta-percha obturation, microscopes, and digital imaging. Prominent new devices and instruments are presented with a brief overview of items listed with a source.

Habituation of Salmonella spp. at reduced water activity and its effect on heat tolerance.

The effect of habituation at reduced water activity (a(w)) on heat tolerance of Salmonella spp. was investigated. Stationary-phase cells were exposed to a(w) 0.

Tissue reactions after subcutaneous and intraosseous implantation of mineral trioxide aggregate and ethoxybenzoic acid cement.

Biocompatibility of mineral trioxide aggregate and ethoxybenzoic acid cement was investigated by subcutaneous and intraosseous implantation of the materials in rats. Tissue reactions were studied at 15, 30, and 60 days after implantation. Subcutaneous implantation of mineral trioxide aggregate initially elicited severe reactions with coagulation necrosis and dystrophic calcification; the reactions, however, subsided to mostly moderate with time.

The application of the Landstuhl frame for air evacuation of patients with femur fractures.

The use of traction to transport patients with femur fractures is well accepted. This paper describes step-by-step the construction of a traction device suitable for use on military aircraft. This "Landstuhl frame" is easily constructed using materials readily available.

Survival and filamentation of Salmonella enterica serovar enteritidis PT4 and Salmonella enterica serovar typhimurium DT104 at low water activity.

In this study we investigated the long-term survival of and morphological changes in Salmonella strains at low water activity (a(w)). Salmonella enterica serovar Enteritidis PT4 and Salmonella enterica serovar Typhimurium DT104 survived at low a(w) for long periods, but minimum humectant concentrations of 8% NaCl (a(w), 0. 95), 96% sucrose (a(w), 0.

The boundary for growth of Zygosaccharomyces bailii in acidified products described by models for time to growth and probability of growth.

Models to predict days to growth and probability of growth of Zygosaccharomyces bailii in high-acid foods were developed, and the equations are presented here. The models were constructed from measurements of growth of Z. bailii using automated turbidimetry over a 29-day period at various pH, NaCl, fructose, and acetic acid levels.

Biocompatibility of two apatite cements.

Biocompatibility and osteogenic potential of two calcium phosphate cements (G-5 and G-6) and Super-EBA were investigated by subcutaneous and intraosseous implantation in 90 rats. Reactions were studied microscopically at 15, 30, and 60 days after implantation. Super-EBA was well tolerated by both soft and hard tissues.

In vitro evaluation of effects of ultrasonic root-end preparation on resected root surfaces.

This in vitro study investigated structural alterations in resected roots that had root-end preparations made with a conventional microhead handpiece and ultrasonics at two intensity levels. Root ends were examined with fluorescence confocal microscopy. Serial histologic sections to the 2 mm levels and then at the level of 3 mm and 4 mm from the resected surface were examined.

Interpretation of chemically created lesions using direct digital imaging.

This study compared conventional radiography to digital imaging in detecting chemically created lesions. Six human cadaver jaw specimens were used. A 70% perchloric acid solution was used to create lesions on the buccal cortical plate of each specimen.

An unusual attempt at surgical repair.

Gold foil was used in an attempt to repair a periapical surgical site in the lower anterior region. This method of repair was used in the past for surgical closure of persistent oroantral fistulas with some success. In this case, it met with failure.

Unusual fracture of a maxillary second premolar.

Root fractures of posterior teeth are rare and occur as a result of severe trauma. This study describes a horizontal root fracture of a maxillary second premolar discovered during routine full-mouth radiographic examination. The tooth was asymptomatic and responded positively to electric pulp testing.