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Biomedical subjects

B L Musikant

Publications and source records attributed to B L Musikant.

At least 19 recordsLinked to original sources
PubMed1992

Retentive properties of attachment sleeves for a new cast-post system.

This study determined the retentive values of various size sleeves and their corresponding post heads when these were cemented with zinc phosphate cement. The experiment was divided into four groups of 10 samples each, except for group 3, which had eight samples. In each instance, the retentive values (measured in pounds) were obtained using a universal testing machine. In all samples studied, the retention of the sleeve was greater than 110 pounds. As the post number increased from 0 to 3, there was a corresponding increase in the retentive force needed to dislodge each sleeve. A maximum of 170.5 pounds was found for the No.3 cast-post sample. Comparison shows that the retention of the sleeve (for this cast-post system) onto the post head is in the same range as crown-to-tooth retention values shown by other investigators.

Cementation↗
PubMed1992

The effects of cold treatment on the physical properties of stainless steel and titanium alloy endodontic posts and instruments.

This study determined whether cold treatment at -96 degrees C affected the mechanical properties of different compositions and sizes of Flexi-Post systems, various sizes of dental reamers, and external wrenches. The experiment was divided into eight groups. The four control groups were untreated and consisted of (1) 50 stainless steel posts, (2) 40 titanium posts, (3) 50 stainless steel reamers, and (4) 10 stainless steel external wrenches. The four experimental groups were cold treated once and twice and included (1) 100 stainless steel posts, (2) 80 titanium posts, (3) 100 stainless steel reamers, and (4) 20 stainless steel external wrenches. The bending or breaking forces were tested on a universal testing machine. Stainless steel Flexi-Post dowels, stainless steel reamers, and external wrenches all showed a significant (ANOVA) (p < 0.05) increase in strength as a result of the single and double cold treatment. Titanium posts showed no strength increase following a single cold treatment, while they were weakened by a double cold treatment.

Analysis of Variance↗
PubMed1992

Comparison of the retentive properties of a sleeve cast crown/core system with crowns cemented to conventional cast cores.

The retention of the crown to the core substructure is of great importance for a successful restoration. The aim of this study was to compare the retentive values of the Flexi-Cast post and its sleeve crown/core complex with that of a crown cemented to a conventional cast post. Forty single-rooted teeth divided equally into four groups were used. Flexi-Cast crown and cores were cemented to Flexi-Cast posts in groups 1 through 3. Group 4, the control group, comprised crowns cemented to conventional cast cores. Groups 1 through 4 had retentive values of 126.2, 135.5, 185.0, and 79.3 lb, respectively. Statistically, the increase in retention for all sizes of the Flexi-Cast crown and cores when compared with the control cast post and crown was found to be significant (p less than or equal to 0.0001).

Cementation↗
PubMed1992

Comparison of retentive properties of four post systems.

This study compared the retention of posts in the root for various diameters (1.3 mm and 1.6 mm) of three prefabricated post systems (Unity, Filpost, and Brasseler) with that of the previously reported No. 1 and No. 2 Flexi-Post systems. The experiment was divided into three groups comprising 10 samples for each post system studied. In group 2, the Filpost system was cemented both with a resin cement and zinc phosphate cement. Retention values were obtained with a modified universal testing machine. The retention of 1.3 mm posts from most to least retentive was Flexi-Post (zinc phosphate) greater than Filpost (zinc phosphate) greater than Filpost (resin) greater than Brasseler (zinc phosphate), greater than Unity (resin). The retention of 1.6 mm posts from most to least was Flexi-Post (zinc phosphate) greater than Filpost (zinc phosphate) greater than Brasseler (zinc phosphate), Unity (resin) greater than Filpost (resin). The Filpost system achieved higher retention with zinc phosphate cement than it did with resin cement.

Cementation↗
PubMed1992

The effect of cold treatment on the physical properties of stainless steel and titanium alloy endodontic posts.

This study determined whether cold treatment at -96 degrees C affected the mechanical properties of various compositions and sizes of the Flexi-Post system. The experiment was divided into four groups of posts. The two control groups were made up of untreated stainless steel (50 posts) and titanium alloy (40 posts). The two remaining cold-treated groups were made up of stainless steel (50 posts) and titanium alloy (40 posts). In each instance the bending or breaking forces were tested on a universal testing machine. Stainless steel Flexi-Post samples showed a significant (p less than 0.05) increase in strength, whereas titanium alloy posts showed no significant increase in strength as a consequence of the cold treatment.

Alloys↗
PubMed1992

Retentive properties of misaligned post attachment sleeves.

This study determined the retention of different sizes of attachment sleeves when cemented in various alignments with the corresponding post heads. This experiment was divided into six groups of eight samples, except for group 6, which had 10 samples. The retention was measured in pounds using a universal testing machine. In all samples, the malalignment of the sleeve to its corresponding post head did not cause loss of retention compared with the control. In groups 1 and 3, and 0.26 mm offset was introduced and this resulted in increased retention for sleeves to the No. 2 and No. 3 cast post heads. These values for the 0.26 mm offset were statistically significant compared with the control. This cast post system offers the dentist a greater safety factor.

Analysis of Variance↗
PubMed1992

Retention properties of a split-shaft threaded post: cut at different apical lengths.

The retention of the post to the root of an endodontically treated tooth is critical for a successful restoration. Modification of the post length to accommodate a specific clinical situation is common. This study compared the retention of No. 1 and No. 2 Flexi-Post restorations shortened apically from 1 to 5 mm with that reported for full-length control No. 1 and No. 2 Flexi-Post dowels. The experimental material was divided into 10 groups with 10 samples in each group. Retentive values were recorded in pounds with a universal testing machine. Analysis of variance with a Tukey-Student range, multiple-comparison test showed no statistical differences from apical reductions of 1, 2, 3, and 5 mm including the full-length control Flexi-Post No. 1 system. With 4 mm of apical shortening statistically greater retention was recorded. No statistical differences resulted with apical reductions of 1 to 4 mm or with the full-length control Flexi-Post No. 2 system, but 5 mm of apical shortening caused significantly less retention.

Cementation↗
PubMed1992

Comparison of the shear bond strength of a titanium composite resin material with dentinal bonding agents versus glass ionomer cements.

This study compared the in vitro shear bond strength of an autopolymerizing composite resin system (CR) (Ti-Core) with two third-generation dentinal bonding agents (DBA) (Tenure and Scotchbond 2) to glass ionomer cements (GIC) (Ketac-Silver, GC Miracle Mix, and Ketac-Cem). The experiment was divided in five groups. The shear bond strengths were evaluated on a universal testing apparatus at three different intervals; 15 minutes, 24 hours, and 7 days. Statistically, (two-way analysis of variance), the shear bond strengths from the greatest to least were: Ti-Core CR with Tenure DBA > Ti-Core CR with Scotchbond 2 DBA > Ketac-Silver GIC, GC Miracle Mix GIC > Ketac-Cem GIC. There were no differences in shear bond strengths according to time, and no interactions between groups and time. The shear bond strengths for Tenure DBA with Ti-Core CR were two and a half to three times greater than the silver-filled glass ionomers, Ketac-Silver GIC and GC Miracle Mix GIC. Tenure DBA with Ti-Core CR also had consistently greater shear bond strengths than Scotchbond 2 DBA with Ti-Core CR, and this trend is in agreement with similar research.

Cermet Cements↗
PubMed1992

Retentive properties of threaded split-shaft posts with titanium-reinforced composite cement.

The retention of posts in tooth roots is vital to the success of the restoration. This study compared the retention of posts of various sizes and diameters cemented with a titanium-reinforced composite cement with that of posts previously reported cemented with zinc phosphate cement. Four groups made up of 10 samples each were used and retention values were compared using a universal testing machine. Two-way analysis of variance and the Newman-Keuls multiple range comparison test were performed. Larger diameter posts cemented with titanium cement had better retention than similar posts cemented with zinc phosphate cement. The statistical increase in retention for the larger size posts is probably the result of the deeper channels (threads) in the dentin and the higher cohesive strength for the titanium-reinforced composite resin.

Composite Resins↗
PubMed1992

Compressive and diametral tensile strength of titanium-reinforced composites.

This article determines the compressive and diametral tensile strength of two titanium-reinforced composites (Bis-GMA-based), Ti-Core and Flexi-Flow cem with titanium and compares their strengths to dentin and commercially available core materials and cements. In addition scanning electron microscope (SEM) photographs were taken of Ti-Core and Flexi-Flow cem with titanium. Compressive and tensile loading was performed on a modified universal testing apparatus. Ti-Core and Flexi-Flow cem with titanium were measured to have compressive strengths of 41,132 and 41,876 psi and tensile strengths of 5219 and 4930 psi, respectively. Statistically (ANOVA, one-way analysis of variance), these titanium-reinforced composites are stronger in compressive and tensile strength than Ketac-Silver, Fleck's zinc cement, Durelon, Ketac-Cem, and GC Miracle Mix. Both titanium-reinforced composite materials approach the compressive and diametral tensile strengths of dentin (43,100 and 6000 psi). SEMs revealed that the titanium was uniformly and homogeneously interspersed within the resin matrix of the material.

Analysis of Variance↗
PubMed1985

Retentive properties of a new post and core system.

Fifty Flexi-Posts were cemented in extracted teeth and tested for tensile strength. The Flexi-Post was the most retentive post tested when compared with posts used in a similar study. The retention of the Flexi-Post became greater as the size of the post increased.

Crowns↗
PubMed1985

Adaptation of a prefabricated post to dentin.

The adaptation of an inventive prefabricated post and core to dentin is presented as part of a series of research reports. The authors suggest that the imaginative design of the split shaft and its telescoping or collapsible apex reduces stress and the finely threaded shaft improves retention.

Crowns↗
PubMed1985

Torque placed by dentists on prefabricated threaded posts.

Thirty-one dentists were tested relative to the optimal and maximum amount of torque they could deliver to posts in teeth. The mean for the optimal amount of torque was 15.55 ounce-inches, and the mean for the maximum amount of torque was 35.29 ounce-inches. Female dentists showed a statistically significantly lower mean difference of 24.5 ounce-inches on the maximum torque test.

Adult↗