Quintessence International, 08/1993

The esthetic influence of gingival architecture on symmetry and tooth length as they relate to the smile line can be altered through periodontal surgical techniques. An internal bevel gingivectomy can be utilized, with some modifications in technique, to increase the beauty of a smile. The practitioner can influence the appearance of the smile by correcting tooth length problems as they relate to upper lip line and correction of right-to-left asymmetries. The surgical techniques are described in detail for various clinical situations.

One hundred twenty-four patients who showed no clinical evidence of acute infection, were not taking antibiotics, and were to undergo routine removal of erupted teeth were studied. Patients were alternately assigned to surgeons who were wearing sterile or nonsterile, but clean, gloves. Surgery was performed in the usual manner and no post-operative antibiotics were prescribed. None of the patients was found to be infected postoperatively. Results of this prospective study suggest that routine exodontia can be safely performed by a surgeon wearning nonsterile, but surgically clean, gloves without increasing the risk of postoperative infection.

A new topical anesthetic agent, EMLA cream 5%, was investigated to determine if long application times could produce a degree of pulpal anesthesia. Thirteen subjects underwent testing in a double-blind manner. Pulpal anesthesia was assessed by electrical pulp testing. After the cream was applied for 15 to 30 minutes, 92% (12/13) of subjects reported no pain to the maximum setting of the pulp tester (300 V). The results of this study suggest EMLA cream has potential application in restorative dentistry and deserves further investigation.

There are several methods of restoring cervical abrasion or erosion lesions, including the use of composite resin, glass-ionomer cement, or a combination of these materials. This paper reports the effectiveness of three different materials and techniques in restoring cervical lesions, using marginal leakage as the means of comparison. Wedge-shaped cervical cavities were preapred so that the gingival cavosurface margin of each cavity involved dentin. Half of the specimens in each group were thermocycled. Differences in marginal leakage were more pronou nced at the gingival margin. There was no significant difference between the leakage of thermocycled and nonthermocycled specimens. Microleakage can be expected to be minimal in cavities restored with the sandwich technique, in which a glass-ionomer cement liner and composite resin restorative material are placed.

Light-hardening glass-ionomer-resin restorative cement was introduced in 1992. Besides having the advantage of rapid initial hardening by application of visible light, the new formulations have better physical properties than do self-hardening glass-ionomer restorative materials. This article documents use of one such cement for restoration of Class II carious lesions in primary molars. The rationale for use of the new cement is reviewed.

The intraoral blue nevus is a benign, relatively rare lesion that usually occurs in adults and most often in wormen. The reported case is interesting because the patient was only 11 years old. THe lesion, located in the hard palate, was surgically removed. The specimen was sent for histologic examination, resulting in the final diagnosis of common blue nevus

This final paper in a series of three uses transmission and scanning electron microscopy to compare the category III dentinal adhesive systems-those with shear bond strength values near or exceeding 17 MPa. Contemporary commercial dentinal adhesive systems such as Superbond and Scotchbond Multi-Purpose, chosen for their varied chemical pretreatments, are contrasted; a contemporary commercial system (Prisma Universal Bond 3) with characteristics of category I and II dentinal adhesives is also included for comparison. The shear bond strength values attained with most category III systems are high enough to cause cohesive failure of the dentin during bond strength testing. This result is attributed to a combination of factors that include effective wetting and penetration of the prepared dentinal surface as well as a tendency to leave collagen fibers at the adhesive-dentin interface in an apparently structurally intact state.

Class II cavities with two retention grooves at the cervical wall, situated at the cemento-enamel junction, were restored with Palfique Light Cured composite resin and one of four different bonding agents and one of two composite resin application techniques. In 80 restorations, any gap present was disclosed by the penetration of a fluorescent resin into the air-filled gap. In another 80 restorations a toluidine blue solution was used to reveal gaps. Tokuso Light Bond and Sueprbond C&B had poor marginal adaptation: gap formation was observed in 90.0% and 57.5% of those restorations, respectively. In contrast, All-Bond had a 20.0% rate and Superbond D-liner had a 12.5% rate of restorations with failur es, represented by very thin gaps in the outer part of the cervical wall. Bulk application of the composite resin material and light curing from the cervical and axial walls through a plastic matrix strip gave results comparable to those of a two-stage horizontal application technique with light curing from the occlusal area and a metal matrix band.