Quintessence International, 04/1991

This case report describes the clinical and laboratory procedures for the fabrication and insertion of In-Ceram all-porcelain, resin-bonded bridges, All-porcelain crowns and fixed partial dentures have better biocompatibility and better esthetic results than do ceramometal restorations. in-Ceram has been shown to have better physical properties than other ceramic or glass materials. However, long-term clinical studies of the material are not yet available.

The problems arising during the maintenance phase of therapy following a combination of periodontal, orthodontic, and restorative treatment are illustrated by this case report. Emphasis is placed on the combined responsibility of the patient, general dental practitioner, and periodontist to recognize signs of recurrent disease at an early stage, thereby allowing corrective measures to be initiated promptly. By applying these principles, even when disease recurs during the maintenance phase, re-treatment is possible and a satisfactory result can be achieved.

Citric acid (pH = 1) was applied passively or by vigorous burnishing for 3 or 5 minutes to diseased human root surfaces following root planing in vitro. Control surfaces were similarly treated with saline only. Teeth were fixed in glutaraldehyde, dehydrated, freeze-dried, and sputter coated with gold for scanning electron microscopic viewing. Results suggested that optimal exposure of collagen and emineralization occurred with the burnishing application of citric acid for 3 minutes. Although somewhat similar results were found with passive application for 5 minutes, the result of the burnishing application for 5 minutes was that the root was overdemineralized or that the exposed collagen was completely obscured by an amorphous layer that was suggestive of protein denaturization.

In clinical practice it is difficult to keep acid etchants off the dentinal surface during bonding procedures. If the acid etchant could be used as part of the overall conditioning system, technique sensitivity would be reduced. This paper reports the data obtained with the use of phosphoric acid as a dentin-enamel conditioner in a bonding system developed by the author. In vitro bond strength and microleakage were examined using Dual Cure Scotchbond as a control. In both ests, the experimental group showed statistically significantly better results than did the control. A clinical study of 140 Class II restorations showed no postoperative sensitivity, and all teeth were vital after 18 months.

Placement of porcelain laminate veneers has become a relatively common procedure. Occasionally it is necessary to fabricate provisional restorations. For these situations, the use of self-curing acrylic resin and composite resin has been described in the literature. Extensive trimming and finishing procedures are often necessary, and because of the inherent fragility of the materials, the provisional restorations are prone to breakage. To improve the technique, visible light-curing acrylic resin can be used to fabricate direct provisional restorations. The material is available in several shades, has excellent manipulative properties, and does not necessarily require a custom matrix, offering significant advantages over a composite resin or self-curing acrylic resin.

The purpose of this study was to assess, in vitro, the microleakage of Class V composite resin restorations following sealing of the margins with a fissure sealant or the resin component of a dentinal bonding agent, and to compare it to the microleakage of an unsealed control group. All groups of teeth showed some degree of leakage at the gingival margin. Statistical analysis showed that there was significantly less leakage when the fissure sealant (P .01) and bonding agent (P .001) were used than there was in the control group, in which the margins had not been sealed. There was no statistically significant difference between the two experimental groups. There was no leakage at the enamel margin in any of the teeth.

A method was developed to give removable appliances a fluoride-releasing capability. Visible light-cured glass-ionomer cement inserts were made, placed in resins commonly used for removable appliances, and evaluated for fluoride release over a 2-month period. Fluoride release was measured daily for 7 days, weekly for 4 weeks, and monthly for 1 month. All specimens released fluoride at every time period. There was a burst effect in which more fluoride was released the first day, but the amount released decreased significantly on the second day. The amount of fluoride released decreased at each of the daily and weekly measurements, but became relatively stable after 7 days. All specimens were still releasing fluoride at the end of the 2-month test period.

Teeth treated with smear layer-mediated dentinal bonding agents and restored with composite resin were examined at the dentin-restoration interface by means of scanning electron microscopy used in conjunction with energy dispersive x-ray analysis. Results indicated that these dentinal bonding agents actually bonded to the smear layer, and samples demonstrated delamination of the smear layer from underlying dentin following thermocycling. This finding suggests that the stresses developed within the composite resin exceeded the adhesive strength of the smear layer to dentin. Thus, the bond strength for dentinal bonding agents that require the presence of the smear layer cannot exceed the adhesion of the smear layer to dentin.

Topical anesthetics are routinely used to reduce the discomfort that patients perceive during dental injections. The purpose of this investigation was to correlate the expectancy of pain and the effect of pretreatment instructions with the severity of pain perceived upon topical anesthetic use and dental injection. The treatment, topical placebo versus topical anesthetic, was administered in a double-blind manner. Following testing for expectations, the administration of instructions, and placement of the topical, the injection was given. The patients were then asked to rate their injection experience on a posttreatment questionnaire. The results of this investigation reinforce the importance of psychological variables in the mediation of pain perceived during dental procedures.

Fourteen patients suffering from primary muscular disease (myopathies), including seven with Duchenne's muscular dystrophy, were compared to 11 patients whose neuromuscular disorders were of neuropathic origin. Mesioclusion was observed only in the group with Duchenne's muscular dystrophy. Posterior crossbite, anterior open bite, mouth breathing, and large tongue were also more prevalent in the group with myopathies, especially the Duchenne's patients, than they were in the group with neurogenic disorders. The Duchenn'es patients exhibited a statistically significant delay in dental emergence, unlike the patients with other myopathies and those with neurogenic disorders. Dentition and occlusion may be more affected in patients with myopathies, especially Duchenne's muscular dystrophy, than they are in patients with neurogenic disorders.