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Biomedical subjects

M A Freilich

Publications and source records attributed to M A Freilich.

16 recordsLinked to original sources
PubMed2003

Shear in flexure of fiber composites with different end supports.

The integrity of fiber-reinforced composite (FRC) prostheses is dependent, in part, on flexural rigidity. The object of this study was to determine if the flexure behavior of uniform FRC beams with restrained or simply supported ends and various length/depth (L/d) aspect ratios could be more accurately modeled by correcting for shear. Experimental results were compared with three analytical models. All models were accurate at high L/d ratios, but the shear-corrected model was accurate to the lowest, more clinically relevant, L/d values. In this range, more than 40% of the beam deflection was due to shear.

Composite Resins↗
PubMed2001

Chairside prefabricated fiber-reinforced resin composite fixed partial dentures.

The introduction of pre-impregnated fiber-reinforced resin composites has provided the dental profession with the opportunity to fabricate and deliver adhesive, esthetic, and metal-free tooth replacements. Utilizing this technology, a prefabricated fiber-reinforced resin composite fixed partial denture prototype that allows rapid, cost-effective, and noninvasive fixed tooth replacement for single anterior teeth has been developed. Ideal situations for this type of service include: a fixed replacement following tooth loss from trauma; a fixed tooth replacement in medically compromised patients who cannot sit for extended periods of time or have local anesthesia; periodontally compromised abutments; a fixed space maintainer following orthodontic movement; and a fixed provisional during the post implant healing phase prior to loading. This article describes the framework construction and placement protocol for the prefabricated fiber-reinforced resin composite fixed partial denture.

Composite Resins↗
PubMed2000

Fiber-reinforced composite framework for implant-supported overdentures.

This article presents a new method for fabricating a framework for an implant-supported overdenture using unidirectional fiber-reinforced composite. This procedure eliminates the need for a traditional metal alloy framework. The fiber-reinforced composite framework has the advantages of lower cost, less time and materials needed during fabrication, minimal potential for toxicity to the technician and patient, and a more esthetic metal-free final result.

Composite Resins↗
PubMed1999

An innovative pre-impregnated glass fiber for reinforcing composites.

This article summarized the development of pre-impregnated, fiber-reinforced composites. Previous efforts with various reinforcement materials for splinting are cited. The benefits of pre-impregnation are explained. The clinical procedure for placing a fiber-reinforced composite splint is described.

Bisphenol A-Glycidyl Methacrylate↗
PubMed1998

Development and clinical applications of a light-polymerized fiber-reinforced composite.

STATEMENT OF PROBLEM: After 0 years of intermittent reports in the literature, the use of fiber reinforcement is just now experiencing rapid expansion in dentistry. PURPOSE: This article describes the development and use of a continuous, unidirectional fiber reinforced composite as a framework for the fabrication of fixed prostheses. METHODS: By using various matrix materials and fibers, a number of fiber-reinforced composite formulations were evaluated with the goal of creating a system with optimized mechanical properties and handling characteristics. Fiber-reinforced composite based on a light polymerized BIS-GMA matrix has been used clinically to make 2-phase prostheses comprised of an internal glass fiber-reinforced composite substructure covered by a particulate composite. The clinical and laboratory procedures required for the fabrication and use of reinforced composite fixed prostheses are described for laboratory-fabricated complete or partial coverage fixed prosthesis and chairside prosthesis. RESULTS: Although additional clinical experience is needed, fiber-reinforced composite materials can be used to make metal-free prostheses with excellent esthetic qualities.

Bisphenol A-Glycidyl Methacrylate↗
PubMed1998

Preimpregnated, fiber-reinforced prostheses. Part II. Direct applications: splints and fixed partial dentures.

This article is the second in a series that describes the development, physical properties, and clinical applications of fiber-reinforced composite materials. The development of fiber-reinforced composite technology has opened new avenues for fabricating direct tooth replacements and splints that are esthetic and simple in design and execution and have the potential for excellent durability. Splinting techniques for hypermobile dentitions or postorthodontic retention and the replacement of anterior and posterior teeth using a groove preparation, a denture tooth, and a fiber-reinforced composite framework will be described.

Composite Resins↗
PubMed1998

Preimpregnated, fiber-reinforced prostheses. Part I. Basic rationale and complete-coverage and intracoronal fixed partial denture designs.

This is the first of two articles describing the development and use of a continuous fiber-reinforced composite as a framework for the fabrication of fixed partial dentures and splints. The chemical composition and physical structure of the fiber-reinforced composite, along with the progression and development of a variety of fiber-reinforced composite materials, are discussed. Criteria for case selection, tooth preparation, and the clinical and laboratory procedures required for partial- or complete-coverage fixed partial denture fabrication and delivery are described.

Composite Resins↗
PubMed1992

Principles for selecting interocclusal records for articulation of dentate and partially dentate casts.

Minimizing the orientation error of the working and opposing casts on the articulator should reduce the extent of intraoral adjustment of restorations before their placement. This article defines and reviews principles such as the tripod of vertical support (three widely spaced occlusal contacts) and adequate horizontal stability, which enable opposing dental casts to be held together in a stable and reproducible manner at the time the mandibular cast is mounted to the articulator. During the restoration of the dentate or partially dentate patient, where restoration is to be coincident with pretreatment maximum intercuspation, the goal of the interocclusal record is to provide stability and/or support for the casts. The types of interocclusal records are organized into categories and designs based upon the remaining vertical support and horizontal stability of the dentition. The clinical indications, limitations, design, and composition of a variety of records for each of these categories are reviewed and discussed.

Dental Articulators↗
PubMed1992

Periodontal effects of fixed partial denture retainer margins: configuration and location.

Our purpose was to study the periodontal response to posterior fixed partial denture (FPD) retainers with different marginal configurations and locations. One posterior proximal site restored with a clinically acceptable FPD and one matched, unrestored posterior proximal site were examined in 60 subjects. Assessments were made of the FPD retainers and the periodontal responses to both the long-term and short-term use of these retainers. Periodontal examination included assessment of probing depth and bleeding on probing and determination of plaque index and the gingival index scores. Statistical analysis showed that "clinically acceptable" FPDs, which had clinically detectable deviations from an ideal (flat) retainer/tooth configuration, were not associated with increased probing depth or bleeding on probing when compared to the matched, unrestored teeth at both examinations. As a group, sites adjacent to subgingival retainer margins were not associated with greater probing depths than sites adjacent to supragingival retainer margins. These findings suggest that long-term exposure to variations of FPD margin configuration and location, within clinically acceptable but less than ideal parameters, are not associated with the destruction of the supporting periodontal tissues.

Adult↗
PubMed1992

Direct and indirect evaluation of posterior composite restorations at three years.

The purpose of this study was to compare the use of direct (USPHS) and indirect (M-L) systems of evaluating the occlusal wear of posterior composite restorations. Additionally, this study has utilized the USPHS method to compare the in vivo performance of posterior resin composite restorations made from four different visible-light-cured materials. Of the 202 restorations placed for this randomized clinical trial, only those restorations that were scored by both direct and indirect evaluation systems were included in these comparisons. Restorations were evaluated by two calibrated examiners from baseline to 36 months. While there were some differences noted among the four materials, the majority (99%) of the restorations evaluated in this study received "alpha" or "bravo" scores for all USPHS parameters, indicating acceptable in vivo performance. The results of this study also indicate that there was a consistent relationship between the direct (USPHS) and indirect (M-L scale) scoring systems. For those restorations that changed anatomic form scores, the mean wear at the alfa/bravo transition was 100 +/- 80 microns. By the 24-month recall examination, the use of the USPHS evaluation system category of anatomic form enabled examiners to differentiate restorations and materials that had experienced little occlusal wear from those that had experienced greater amounts of wear.

Analysis of Variance↗
PubMed1992

Three-year occlusal wear of posterior composite restorations.

The specific aims of this study were to: 1) measure the occlusal wear of four different dental composite materials placed in the posterior teeth of adults; and 2) evaluate the effect of the clinical parameters, cavity class and tooth type on occlusal wear. Four different visible light-cured composite materials were used to make the restorations in this study. The restorations placed for this randomized clinical trial were scored through the use of an indirect evaluation system (M-L scale). The total sample size per recall ranged from 90 to 142 restorations from baseline to 36 months. The mean wear at 36 months for Heliomolar, J&J Experimental (Adaptic II) and P-30 was 45-54 microns, which is rather low compared to the recently reported wear of other composite materials. Marathon exhibited significantly greater wear with a mean of 174 microns at 36 months. The data also showed that cavity class and tooth type had no significant effect on the occlusal wear of the restorations made with the three low wear-rate materials, while restorations composed of the high wear-rate material exhibited more wear in molars than premolars; this effect was again not statistically significant. These data support the hypothesis that the overall wear of a composite restoration is more dependent on the material's properties than clinical parameters such as cavity class and tooth type.

Acrylic Resins↗
PubMed1991

Fixed partial dentures supported by periodontally compromised teeth.

This study tested the effect of fixed partial dentures on hypermobile abutment teeth with substantially reduced levels of periodontal attachment. One abutment tooth and one control (nonabutment) tooth of the same type and periodontal condition were selected for study in adults. Treatment consisted of periodontal therapy and a 3- or 4-unit fixed partial denture, after which all subjects were placed on a quarterly maintenance schedule. No differences were found between the mean baseline and 24-month measures for all dependent variables at test or control sites.

Adult↗
PubMed1990

The effects of resin-bonded and conventional fixed partial dentures on the periodontium: restoration type evaluated.

The purpose of this study was to compare the long-term and short-term periodontal response to three different modalities of fixed prosthodontic tooth replacement. Posterior proximal sites adjacent to abutment teeth supporting etched metal and two designs of conventional fixed partial dentures (FPDs) were assessed 6 months to 5 years after insertion. For the long-term observation, the etched metal resin-bonded FPDs had significantly greater plaque scores than both of the conventional designs. The resin-bonded FPD group had statistically, but not clinically, significant increased probing depths than the supragingival FPD group. In spite of the increased levels of supragingival plaque associated with the etched metal FPD, this type of fixed prosthesis was no more injurious to the periodontium than the subgingival conventional FPD designs.

Adult↗
PubMedDate not supplied

Combined use of intersubject and intrasubject controls to distinguish treatment versus patient effect in retrospective studies.

Clinical researchers seek to eliminate specific subject attributes from becoming confounding variables to distinguish a treatment effect from an underlying patient effect. In prospective studies, the random assignment of subjects into experimental groups results in the equal distribution of subject attributes, thereby eliminating them as confounding variables. Retrospective study designs, often used in prosthodontics research, preclude the random assignment of subjects. This article describes the application of a standard research design that combines the use of intersubject and intrasubject controls to compensate for the potential imbalance in subject attributes in retrospective clinical studies. This approach should help prevent clinical investigators from declaring differences between experimental groups when, in fact, no differences exist.

Confounding Factors, Epidemiologic↗