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Biomedical subjects

Jason M Mailhot

Publications and source records attributed to Jason M Mailhot.

5 recordsLinked to original sources
PubMed2004

An evaluation of the origin of trabecular bone patterns using visual and digital image analysis.

OBJECTIVE: The purpose of this research project was to investigate the origin of the anatomical structures interpreted as trabecula bone on dental radiographic images. STUDY DESIGN: Mandible sections were cut sagitally into halves. Trabecular bone was removed from each section in 4 stages. Following each stage, standardized radiographs were made, using CDR direct digital equipment. Trabecular bone in the resulting digital images was measured with 4 methods: (1) mean gray level; (2) the fractal dimension of the basic images; and, following morphological image processing, (3) counting the number of trabecular ends, intercepts, and segments (EIS) and (4) performing fractal analyses of the skeletonized images. Additionally, human visual interpretation of the collected images was conducted through a written examination. Repeated measures analysis of variance (ANOVA) was used to test for changes in measurements attributable to bone removal. RESULTS: Repeated measures ANOVA indicated that the use of gray levels, fractal dimension, and morphologic operations quantifying using EIS or fractal analysis had similar performance and resulted in significant changes in measurements following bone removal ( P < .05). Visual differences were not always apparent between each stage of bone reduction. Radiometric and morphologic analysis showed measurable differences between stages. CONCLUSIONS: These results imply that the inner trabecula, the junctional trabecula, and the actual cortical housing all contribute to some extent to the radiograph, although changes in the radiographic architecture are not always clinically detectible.

Absorptiometry, Photon↗
PubMed2003

In vivo effectiveness of a glycerol-compounded demineralized freeze-dried bone xenograft in the rat calvarium.

BACKGROUND: Demineralized freeze-dried bone (DFDB) is commonly hydrated with sterile water into a paste-like consistency for improved clinical handling or reconstituted with biodegradable barriers, such as glycerol, to promote handling and wound stability following human periodontal surgery. The purpose of this study was to evaluate the in vivo effects of glycerol-compounded human DFDB on bone formation in the rat calvarial critical-sized defect (CSD) model. METHODS: Forty-eight adult male Harland Sprague-Dawley rats were assigned to one of four treatment groups: glycerol, DFDB, DFDB plus glycerol, or a non-grafted control, and placed into 8 mm calvarial CSDs. DFDB (particle size 0.106 to 0.5 mm), glycerol, and their combination were from identical sources. Calvaria were harvested at 8 weeks postsurgery and evaluated histomorphometrically. RESULTS: A statistically significant increased percentage of total bone fill was detected in the glycerol plus DFDB group and DFDB group as compared to glycerol group or the control. However, no significant difference was noted between the DFDB plus glycerol group and the DFDB group. CONCLUSION: The addition of glycerol to DFDB results in comparable osseous regeneration in the rat calvarium defect model versus DFDB alone; however, based upon clinical judgment, handling characteristics of DFDB were greatly improved.

Analysis of Variance↗
PubMed2003

Digital image analysis of cadaver mandibular trabecular bone patterns.

BACKGROUND: The purpose of this study was to investigate the source of radiographic trabecular patterns by removing trabecular bone in four sequential steps from six cadaver mandible sections, radiographing the sections after each removal, and using four digital-image analysis methods to quantify any resulting changes to the radiographs. METHODS: Mandible sections were cut sagittally into halves. Trabecular bone was removed from each section in four stages. Following each stage, standardized radiographs were taken, using direct digital equipment. Trabecular bone in the resulting digital images was measured with four methods. Mean gray level values (method 1) and cumulative percent histograms (method 2) were calculated from the raw data. Morphological image processing was used to skeletonize the trabecular structure, which was quantified by counting the number of trabecular ends and segments in the skeletonized images (method 3) and performing fractal analyses of the skeletonized images (method 4). Repeated measures analysis of variance (ANOVA) was used to test for changes in measurements attributable to bone removal. RESULTS: Repeated measures ANOVA indicated that the use of gray levels, cumulative percent histograms, and morphologic operators resulted in highly significant changes in measurements following bone removal (P < 0.01). Ends and segments demonstrated similar performance, with changes highly significant over time (P < 0.01). Fractal analysis also resulted in highly significant changes over time (P < 0.01). CONCLUSIONS: The analyses performed in this study demonstrated consistent image differences following the four steps of bone removal. These differences appeared whether light, cancellous bone or heavier endosteal bone was removed. These findings indicate that trabecular and endosteal bone combine to form the structure that most dentists identify as trabeculae on intraoral radiographs.

Analysis of Variance↗
PubMed2003

The effects of EDTA gel conditioning exposure time on periodontitis-affected human root surfaces: surface topography and PDL cell adhesion.

OBJECTIVE: The purpose of this investigation was to study the surface topography of periodontally-affected human roots following EDTA gel application at different time periods with and without scaling and root planing. In addition, to assess any correlations between root surface changes following EDTA gel conditioning and periodontal ligament fibroblast adhesion. METHODS: Forty-eight teeth that had a labial probing depth and clinical attachment loss of more than 7mm were used in this study. Periodontally-affected teeth were randomly divided into 4 groups of 12 teeth in each. Furthermore, a sample group of 6 teeth, which had a healthy periodontium, were used to serve as the healthy control (G1). The second group (G2) served as a diseased treated control in which sample teeth were only scaled and root planed prior to immediate extraction. Teeth in the third group (G3) were conditioned with a pH neutral, 24% Ethylenediaminetetraacetic acid (EDTA gel), for 2 minutes without any scaling or root planing and immediately extracted. The teeth in the fourth group (G4) were scaled, root planed, and then conditioned with the EDTA gel preparation for 2 minutes before immediate extraction. Finally the teeth in the fifth group (G5) were conditioned with EDTA gel for 4 minutes following scaling and root planing and immediately extracted. Half the samples in each group were randomly selected and processed for SEM evaluation of the surface topography. The other half were prepared to assess PDL cell adhesion with PDL fibroblasts being cultured and seeded on the root surface for 24 hours then processed for SEM evaluation of the adherent cells. RESULTS: SEM evaluation of the root planed surfaces in G2 revealed the typical appearance of a smear layer. The root surfaces of all samples in G3 exhibited a uniform coating of calculus that was covered by a considerable amount of loosely attached material including residual plaque and debris. In G4 EDTA gel exposure for 2-minutes following scaling and root planing resulted in removal of the smear layer and a marked exposure of round to oval dentinal tubule orifices. Areas of bacterial accumulation were observed in 4 out of the 6 samples examined in this group. The root surfaces after the 4-minute EDTA gel application (G5) had a fibrillar texture associated with a marked decrease in the number and an increased diameter of the exposed dentinal tubule openings. With regard to PDL cell adhesion, the majority of the 2-minute EDTA gel conditioning on the non-instrumented samples in G3, showed a failure of cells to adhere to the diseased root surface. The examined samples in G4 showed a significant increase in the number of flat and round adherent cells when compared to the diseased control samples (G2) (P > or = 0.01). The G5 samples showed a significant increase in the number of flat cells when compared to G4 (P > or = 0.01). CONCLUSION: The present study confirms the capability of EDTA gel to remove a root surface associated smear layer and to expose a collagen matrix when it was applied after scaling and root planing. In addition, a positive correlation was found between time of EDTA gel conditioning and the degree of PDL cell adhesion. It appears from the present investigation that EDTA gel conditioning for 4 minutes provides the most desirable root surface to which maximum PDL cells can adhere and on which they can grow.

Adult↗