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Biomedical subjects

A Ben-Amar

Publications and source records attributed to A Ben-Amar.

At least 37 records · Page 2Linked to original sources
PubMed1990

The effect of posterior composite restorations on the resistance of cavity walls to vertically applied occlusal loads.

The resistance of the cavity walls of non-vital premolars to vertically applied occlusal forces was studied. Standardized MOD cavities were prepared, restored, and vertical forces were applied to each of the cuspal tips by the Instron machine. Results suggest that bevelled etched-enamel margins and dentine-bonded posterior composite resin restorations significantly improved (by 33%) the resistance of the remaining cavity walls compared to amalgam restorations. In a control group, in which no restorations were carried out in the prepared cavities, the resistance of the walls was significantly smaller than in both restored groups.

Bicuspid↗
PubMed1989

Long-term sealing properties of amalgam restorations: an in vitro study.

Conventional and high-copper Class V amalgam restorations showed leakage after seven months' storage in artificial saliva and thermal-stressing. The rate of marginal microleakage was not significantly affected by the application of a Copal varnish after this period. At the 14-month storage and thermal-stressing period, all varnished and unvarnished high-copper restorations and the varnished conventional amalgam restorations showed significantly improved sealing properties in the occlusal wall compared with the seven-month period. The unvarnished conventional amalgam restorations appeared to have reached their peak sealing level by seven months under the conditions of this experiment. No significant improvement in the sealing properties of either the conventional or high-copper amalgam restorations was achieved after the 14-month period by the application of Copal varnish.

Copper↗
PubMed1989

Joint strength between two layers of different amalgam types condensed successively.

The flexure strength of the joint between layers of different types of amalgam condensed consecutively one on to the other was evaluated in vitro. The data indicated no statistical differences in flexure strength between the combined samples (single composition spherical and lathe-cut eutectic amalgams) and the control (homogeneous lathe-cut eutectic amalgam).

Dental Alloys↗
PubMed1989

Conditioning of root canals prior to dowel cementation with composite luting cement and two dentine adhesive systems.

Two hundred and forty root canals of extracted single-rooted teeth were prepared to the same dimension, and Dentatus posts of equal size were cemented without screwing them into the dentine. Five cleansing solutions and two dentine adhesive systems were evaluated prior to post-cementation using chemical-cure composite resin. 'Pull-out' tests were then conducted in order to evaluate the bond strength of these intra-pulpal posts. The use of Conclude (composite luting cement) alone, with or without the cleansing solutions, resulted in significantly lower pull-out forces. Scotchbond Dental Adhesive gave significantly better results, regardless of the cleansing solution used. Gluma Dentine Adhesive significantly increased the pull-out forces only when used with its supplied cleanser or Tubulicid.

Acrylates↗
PubMed1989

The effect of ultrasonic cleaning and air polishing on the marginal integrity of radicular amalgam and composite resin restorations. An in vitro study.

This study attempts to put at ease some uncertainty of a possible damaging effect of ultrasonic scaling and air polishing procedures on dental restorations (amalgam and composite resin). Under optimal in vitro conditions, the margins of 120 restorations were subject to thorough ultrasonic and air polishing instrumentation in order to mimic those extensively used in periodontal treatments. Light-cure composite resin and Dispersalloy amalgam alloy were used to restore class V cavities at the CEJ. After being exposed to ultrasonic scaling and air polishing, cleaning, and thermocycling, clinical evaluation of the cavity margins and microleakage examination showed no detrimental effects of these procedures.

Air↗
PubMed1989

Reduction of microleakage around new amalgam restorations.

Microleakage is a problem of all fresh amalgam restorations and is clinically undetectable. Because microleakage may be responsible for pulp irritation, pulp inflammation, necrosis, and recurrent caries, it is essential to prevent and control it. Correct cavity margin preparations, proper amalgam manipulation, proper condensation, and burnishing can minimize microleakage in amalgam restorations. The use of conventional varnish or dentin adhesive on cavity walls before the insertion of the amalgam is the best method to reduce microleakage. Most well-manipulated and well-placed amalgams do not exhibit microleakage after a time.

Bacteria↗
PubMed1989

Amalgam restoration completion. Objectives, methods and armamentarium.

The success of an amalgam restoration is multifactorial. Attention must be paid to the manipulation and condensation of the alloy, the final contouring, and the finishing procedures. A discussion of current amalgam alloy, including the goals and sequence of the restorative procedure, are presented with emphasis on the instruments and methods.

Dental Amalgam↗
PubMed1988

The effect of retention grooves on gingival marginal leakage in Class II posterior composite resin restorations.

In this laboratory study, the effect of retention grooves in the proximal portion of class II cavities on the marginal microleakage using light-cured composite resin was examined. The retention grooves were placed at the axio-facial and axio-lingual line angles and in the gingival floor of the cavities. The teeth were restored with Herculite composite resin with etching and dentine bonding and polymerized in two different ways: (i) a single mass of restorative material was polymerized all at once; and (ii) incrementally placed amounts of restorative material were each polymerized separately until the cavity was completely filled. Marginal microleakage was evaluated by the degree of dye penetration at the gingival margin of the restorations after suitable thermocycling procedures. It was concluded that marginal microleakage was significantly reduced when the composite resin was placed and polymerized incrementally, and that no advantage was gained from retention grooves with this incremental technique. However, when polymerizing in one single mass of material, retention grooves were found to be necessary in order to reduce marginal microleakage at the gingival wall.

Acid Etching, Dental↗
PubMed1987

Cavity design for class II composite restorations.

Preparation design for posterior composite restorations should differ from that for amalgam restorations in the following manner. Occlusal form should be narrower and the depth shallower. The proximal extensions (facial and lingual) should be placed in areas that can be seen, probed, and polished. Internal line angles should be rounded and retenive grooves placed in proximal line angles (axiofacial and axiolingual) and the gingival wall. Beveling is recommended for proximal margins but not for occlusal margins.

Composite Resins↗