A pilot investigation of enamel reduction procedures. (1/9)

OBJECTIVE: To test and describe the use of various combinations of mechanical and chemical techniques for enamel reduction to obtain a smooth surface. METHODS: Bovine teeth (2 surfaces on each of 32 teeth) were used. The teeth were mounted in blocks of dental plaster, which were then mounted in a vise. The mesiodistal enamel contact areas were reduced by various combinations of mechanical and chemical aids. The mesiodistal width of each tooth was measured with a digital caliper after initial reduction of the enamel surface and again after polishing. The teeth were subsequently prepared and mounted for scanning electron microscopy. RESULTS: All combinations yielded statistically significant enamel reduction (p < 0.05). The use of acid stripping in conjunction with mechanical procedures produced especially smooth enamel surfaces. CONCLUSIONS: Steps must be taken to ensure that a smooth enamel surface remains after enamel reduction and polishing. It is recommended that conventional enamel etchants be added to the polishing procedure. Enamel reduction can increase available space, but the quantity of enamel that can be removed without adverse consequences should be carefully evaluated.  (+info)

Cutting characteristics of dental diamond burs made with CVD technology. (2/9)

The aim of this study was to determine the cutting ability of chemical vapor deposition (CVD) diamond burs coupled to an ultrasonic dental unit handpiece for minimally invasive cavity preparation. One standard cavity was prepared on the mesial and distal surfaces of 40 extracted human third molars either with cylindrical or with spherical CVD burs. The cutting ability was compared regarding type of substrate (enamel and dentin) and direction of handpiece motion. The morphological characteristics, width and depth of the cavities were analyzed and measured using scanning electron micrographs. Statistical analysis using the Kruskal-Wallis test (p < 0.05) revealed that the width and depth of the cavities were significantly greater when they were prepared on dentin. Wider cavities were prepared when the cylindrical CVD bur was used, and deeper cavities resulted from preparation with the spherical CVD bur. The direction of handpiece motion did not influence the size of the cavities, and the CVD burs produced precise and conservative cutting.  (+info)

Cervicofacial and mediastinal emphysema complicating a dental procedure. (3/9)

Cervicofacial subcutaneous emphysema is an infrequently reported sequela of dental surgery. It may be caused by the inadvertent introduction of air into the soft tissues during procedures using high-speed, air-driven handpieces or air-water syringes. In this paper, we present a case in which subcutaneous emphysema developed in a middle-aged woman following routine restorative treatment. We review the features of the condition and its treatment and discuss means of prevention.  (+info)

Dental anxiety among university students and its correlation with their field of study. (4/9)

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Bone damage induced by different cutting instruments--an in vitro study. (5/9)

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Influence of grinding procedures on the flexural strength of zirconia ceramics. (6/9)

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Learn-a-prep II as a predictor of psychomotor performance in a restorative dentistry course. (7/9)

This investigation assessed whether early student performance with a dental handpiece on a didactic training aid known as the Learn-A-Prep II (LAP II) was predictive of performance on subsequent practical examinations in a preclinical restorative dentistry course. Eighty-one first-year students were given initial handpiece training and formative feedback using the LAP II and were then instructed to independently prepare four LAP II patterns within the pattern lines and at a specified depth. Performance on the LAP II was compared with the summative assessment on two subsequent amalgam preparation practical examinations given at the middle (Class II) and end (Complex) of the course. Pattern preparation within the lines did not significantly improve the likelihood of receiving an A or B on the Class II practical (p=0.53) or on the Complex practical (p=0.37). Students who had an acceptable depth on the LAP II were 3.73 times more likely to receive an A or B on the Class II practical than those students who did not have acceptable depth (p=0.03). Performance at an acceptable depth did not significantly improve the likelihood of receiving an A or B on the Complex practical (p=0.15). The LAP II may aid in identification of students who would benefit from early intervention with additional focused instruction.  (+info)

An evaluation of dental operative simulation materials. (8/9)

The study was to evaluate the performance of different materials used in dental operative simulation and compare them with those of natural teeth. Three typical phantom teeth materials were compared with extracted permanent teeth by a nanoindentation system and evaluated by students and registered dentists on the drilling sensation of the materials. Moreover, the tool life (machinability) of new cylindrical diamond burs on cutting the sample materials was tested and the burs were observed. Although student and dentist evaluations were scattered and inconclusive, it was found that elastic modulus (E) and hardness (H) were not the main factors in determining the drilling sensation of the materials. The sensation of drilling is a reflection of cutting force and power consumption.An ideal material for dental simulation should be able to generate similar drilling resistance to that of natural tooth, which is the machinability of the material.  (+info)