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Biomedical subjects

Barry Lee Musikant

Publications and source records attributed to Barry Lee Musikant.

12 recordsLinked to original sources
PubMed2006

Post design and its impact on the root and crown.

To optimize the longevity of an overlying restoration, it is important to follow proper engineering principles. These include the requirement of either an internal or external ferrule. When sufficient tooth structure does not exist to support an internal ferrule, it becomes necessary to use a porcelain-fused-to-metal restoration. The posts supporting these restorations should have low insertional stresses, high retentive values, and an even distribution of functional stresses. In the author's opinion, the split-shanked design of the Flexi-Post and Flexi-Flange is the only design that can deliver this essential combination. The purpose of a post is to help restore or reinforce the coronal structure of a tooth to further increase the retention and stability of an artificial crown. Removing tooth structure to place a post does not increase the root's resistance to vertical or horizontal fracture.

Dental Prosthesis Design↗
PubMed2005

Radiopacity of dental materials using a digital X-ray system.

OBJECTIVES: Radiopacity is a desirable property for most intra-oral materials. There are established ISO and ANSI/ADA protocols for determining radiopacity using film-based radiography. However, these methods are not always followed by researchers. This study aims to adapt those procedures by using digital radiography, a simplified stepwedge, and examine the effects of target distance and exposure time choice. METHODS: One millimetre thick samples of three dental materials were prepared by placing the materials into a 1.00 mm thick washer sandwiched between two glass slides. The samples were digitally radiographed alongside a stepwedge of aluminum alloy 1100 with an X-ray unit at 70 kVp using five different target distance/exposure time combinations. For each combination, the grey scale values of various thicknesses of the stepwedge were converted into absorbencies and plotted against their thickness. These plots were then linearly regressed in order to correlate absorbance with a thickness of aluminum for each target distance/exposure time combination. The absorbencies of each sample were then converted into radiopacities using these correlations. RESULTS: The correlations between the absorbance of the stepwedge and its thickness were highly linear. This linearity allows the correlation to be accurately deduced from fewer data points than required by the ISO and ANSI/ADA protocols. Varying exposure time did not significantly affect the mean radiopacity measured at a target distance of 30 cm. Varying the target distance did not significantly affect the measured radiopacity as long as the samples were properly exposed. SIGNIFICANCE: A simplified, consistent digital method for determining radiopacity is presented.

Absorptiometry, Photon↗
PubMed2005

Morphological measurements of anatomic landmarks in pulp chambers of human maxillary furcated bicuspids.

The aim of this in vitro study was to measure key morphological features of pulp chambers from furcated maxillary bicuspid teeth. There were 107 random human maxillary bicuspid teeth used. Each bicuspid was radiographed using the Trophy RVG digital imaging system and a Belmont Acuray X-ray at 70 kVp. Measurements were made using the Digipan measuring mode of the Trophy system. Results were mean (mm): pulp chamber floor to furcation: 1.85 +/- 0.85; pulp chamber ceiling to furcation: 4.61 +/- 1.04; cusp to furcation: 11.55 +/- 1.12; cusp to pulp chamber ceiling: 6.94 +/- 0.70; pulp chamber height: 2.76 +/- 0.97. The measurements showing the lowest percentage variance were: cusp to furcation (9.70%) and cusp to pulp chamber ceiling (10.09%). The only measurement that was statistically the same across maxillary molars, mandibular molars and bicuspids was measurement "B," pulp chamber ceiling to furcation. The critical distance from cusp tip to pulp chamber ceiling in bicuspids was approximately 7.00 mm.

Analysis of Variance↗
PubMed2004

Comparison instrumentation reamers and files versus a flat-sided design of conventional noninterrupted, flat-sided design.

The in vitro study measured the time required to instrument and shape canals by conventional reamers and files compared with a newly introduced reamer and file system. This experiment was divided into four groups with 10 block samples for each group. The results of instrumentation time demonstrate that the noninterrupted flat-sided design (EZ-Fill SafeSider reamers) produced the fastest times for comparably shaped canals because of reduced engagement of the instrument with the walls of the canal compared with conventional instruments. The conventional designs for both reamers and files result in increased instrumentation time compared with their EZ-Fill SafeSider counterparts.

Acrylic Resins↗
PubMed2004

Morphological measurements of anatomic landmarks in human maxillary and mandibular molar pulp chambers.

The aim of this in vitro study was to measure critical morphology of molar pulp chambers. One hundred random human maxillary and mandibular molars (200 teeth in total) were used. Each molar was radiographed mesiodistally on a millimeter grid. Using a stereomicroscope, the measurements were read to the nearest 0.5 mm. Results were as follows (mean, mm): pulp chamber floor to furcation, maxillary = 3.05 +/- 0.79, mandibular = 2.96 +/- 0.78; pulp chamber ceiling to furcation, maxillary = 4.91 +/- 1.06, mandibular = 4.55 +/- 0.91; buccal cusp to furcation, maxillary = 11.15 +/- 1.21, mandibular = 10.90 +/- 1.21; buccal cusp to pulp chamber floor, maxillary = 8.08 +/- 0.88, mandibular = 7.95 +/- 0.79; buccal cusp to pulp chamber ceiling, maxillary = 6.24 +/- 0.88, mandibular = 6.36 +/- 0.93; and pulp chamber height, maxillary = 1.88 +/- 0.69, mandibular = 1.57 +/- 0.68. The pulp chamber ceiling was at the level of the cementoenamel junction in maxillary, 98%, and mandibular, 97% of the specimens. The measurements showing the lowest percentage variance were buccal cusp to furcation (approximately 11%) and buccal cusp to pulp chamber ceiling (approximately 14%). The measurements were similar for both maxillary and mandibular molars.

Dental Pulp Cavity↗
PubMed2004

Endodontic techniques defined by principles.

Traditional endodontics, limited to the use of K-files, has proven so inefficient in achieving predictable superior results that its deficiencies led to the development and adoption of rotary NiTi systems that produce far superior results, often with much less physical effort. However, in tight curved canals, the inherent weakness of rotary NiTi to both torsion and cyclic fatigue has led to a troubling number of fractured instruments lodged in the canals. The introduction of the SafeSider instrumentation system eliminates the problems of both traditional K-file instrumentation and the fractured instruments associated with rotary NiTi, while delivering superior results in a time-efficient manner.

Root Canal Preparation↗
PubMed2003

Inductively coupled plasma-emission spectroscopy and atomic absorption for the use of elemental analysis of a root canal after lasing with a holmium:YAG laser.

It has been reported in the literature that after lasing dentin the dentin surface has a glassy or globular appearance. Many authors believe this to be recrystallized hydroxyapatite. The purpose of this elemental analysis was to see if any of the silica fiber optic was melted and deposited as these globular structures on the canal wall. Two teeth were used. One was hand-instrumented with files and used as the control, the other was lased with a holmium:YAG laser. A 245-micro low OH- fiber was used with a power setting of 0.75 W, 5 Hz, 94.2 J, and 1134 V to lase the root. The roots were microanalyzed for oxygen, phosphorus, silicon, nitrogen, hydrogen, calcium, and carbon. The percentages for all elements tested were the same for both teeth. Therefore, there was no silicon deposited onto the canal wall of the tooth that was lased. It is concluded that the low OH- silica fiber optic was not melted and deposited onto the dentinal canal wall.

Aluminum Silicates↗
PubMed2003

A two-and-a-half year perspective on simplified endodontic techniques.

Simplified Endodontic Techniques (SET), along with EZ-Fill, a bidirectional spiral and epoxy root canal cement, have been used for more than 2 1/2 years. This particular sequence of instrumentation and obturation provides the dentist with predictable and easily attained success. Periapical areas demonstrate healing, and excess EZ-Fill cement is resorbing. Postoperatively, patients experience approximately 80% less pain in both occurrence and intensity. The adoption of SET, along with EZ-Fill, allows dentists to significantly increase their productivity while dramatically improving the quality of their work.

Absorbable Implants↗
PubMed2002

The effects of eugenol and epoxy-resin on the strength of a hybrid composite resin.

The compatibility of different dental materials (root canal sealer and composite core build-up restoratives) is an important factor for a successful restoration. The aim of this in vitro study was to determine the effects on compressive and diametral tensile strength of a classical chemical cure composite resin (Henry Schein Composite Anterior-Posterior dental restorative) when in contact with either eugenol or an epoxy-resin (EZ-Fill) in a variety of situations: (a) eugenol or epoxy-resin added during mixing of a composite resin before curing; (b) vapor exposure to cured samples; and (c) specimens placed directly in eugenol or epoxy-resin (after curing). Compressive strengths and diametral tensile strengths were tested for each group. Only the addition of eugenol during mixing with the composite resin (directly before curing) resulted in specimens that were unable to be tested, because they did not achieve a full cure or hardness. For all other groups, there were no significant differences with respect to either compressive strength (p = 0.17) or diametral tensile strength (p = 0.39). Group 1 (mixed directly with eugenol) was found to be statistically different from groups 2 through 7.

Analysis of Variance↗