Quintessence International, 12/1994

Even though there has been much interest in dental bleaching in recent years, little has been reported about patient-applied carbamide peroxide tooth bleaching for children and adolescents. This technqiue article describes at home tooth bleaching for young patients and offers a proven protocol for the procedure. Representative cases are documented with pretreatment and posttreatment photographs. Bleaching in conjunction with enamel microabrasion is also reviewed.

The purpose of this study was to evaluate in vivo changes in the pH of plaque and of a 10% carbamide peroxide solution occurring within the bleaching gurad during a 2-hour nightguard vital bleaching prcedure. Baseline pH values for plaque and the carbamide peroxide solution were established. A small hole was placed in the anterior interproximal region of the guard to allow placement of the pH electrode. The pH of the carbamide peroxide solution was meausred at 5-minute intervals. After 2 hours, the guard was removed and pH of the plaque was remeasured. The procedure was repeated three times on each of four subjects. The mean baseline pH reading for plaque was 6.31 and mean final pH reading was 6.86. The difference was statistically significant. At initial placement of the carbamide peroxide-filled guard, the mean intraguard pH was 4.50 (range of 2.80 to 7.80). The mean peak intraguard pH of 8.06 (range of 7.30 to 8.43), which was significantly different from baseline, was obtained within 31 minutes. The pH of plaque, saliva, and a 10% carbamide peroxide bleaching solution within the guard increased significantly during bleaching and remained significantly elevated for the duration of the study (2 hours).

The use of implant-retained complete overdentures is a viable treatment modality in compromised patients. Use of two separate implants in the mandible enhances the retention and stability of the denture, which is still mainly supported by soft tissues. A technique for clinical fixation of the internal attachment to a laboratory-rebased and tissue-loaded mandibular overdenture is described. The advantages, disadvantages, and the rationale of the treatment are presented.

This study compared the shear bond strengths and the prosity at the bond sites of a spherical amalgam alloy to those of an admised amalgam alloy, when they were bonded to like and unlike alloy specimens with or without a resin bonding material. The spherical alloy had higher bond strength and less porosity than did the admixed alloy, whether bonded to spherical or admised alloy. The results suggest that use of a spherical alloy should be strongly considered when an amalgam restoration is to be repaired with an amalgam alloy, regardless of the type of alloy used in the original restoration. Use of a resin bonding agent did not increase bond strengths of amalgam to amalgam.

A technique used to repair the abutment tooth of a fixed partial metal-ceramic prosthesis is described. This prosthesis extended from the maxillary central incisor to the left canine. The whole porcelain facial aspect of the central incisor had been fractured. Following a reduction of t he metallic structure, a single porcelain crown was bonded to that area. The repair was quick, less expensive and less difficult than removal of the prosthesis and fabrication of a replacement, and provided excellent estethic and functional results.

The term epidermolysis bullosa describes a group of rare genetic mechanicobullous disorders. The disease has several modes of inheritance with various degrees of severity and expression. A patient with simplex epidermolysis bullosa had typical cutaneous lesions and dental involvement. The teeth were severely affected by hypoplasia. Dental therapy consisted of placement of amalgam restorations and topical applications of fluoride. The need for, and advantages of, early preventive and restorative dental care are illustrated by the case presente

A clinical trial was carried out to evaluate the influence of incision and reflection of a flap on pain after the removal of partially erupted mandibular third molars. A sequential design for intraindividual comparisons was chosen. The patients underwent bilateral extraction of partially impacted mandibular third molars with a standard incision on one side (control) and without incision (test) on the other side. One week postoperatively, the patients were asked on which side they had experienced more postoperative pain. The preset level of significance (P .05) was reached after 11 patients were treated. Eight patients had more severe pain on the control side, while three patients did not experience any difference in pain between the two sides. The nonsurgical approach did not increase the chair time and appeared to be an effective way of reducing postoperative discomfort after extraction of partially erupted third molars.

The effects of the dentinal surface treatments from six currently available commercial dentinal adhesives are presented. The adhesives are All-Bond 2, etched and unetched, Syntac, Prisma Universal Bond 3, Scotchbond Multipurpose, Tenure Solution, and Adhesive By Choice. Unerupted third molar human teeth were sectioned and treated with the appropriate adhesive according to the manufac turer's directions. After the teeth were treated, they were processed for observation by scanning electron microscopy. Scanning-electron microscopic photomicrographs were made of each step in the process to show the effects of the constituents, including the adhesives, on the dentinal surface. For All-Bond 2, unetched, the smear layer was not removed before the primer and the adhesive were applied. The primer for Prisma Universal Bond 3 algtered the smear layer by reacting with it but did not produce a large demineralized zone in the dentin. All the other adhesives did remove the smear layer before the tooth was treated with the primer and adhesive.

The wetting property of dentinal bonding systems may play an important role in the mechanism of adhesion to dentin. Some studies have observed that tags penetrate 100 um or more in nonvital teeth and less than 10 um in vital teeth. This investigation was designed to evaluate the micromorphologic relationship between in vivo and in vitro dentin after application of two new dentinal bonding systems in Class II restorations. Class II cavities were restored in vitro and in vivo with Gluma 2000 adhesive and Pekafill hybrid resin or Scotchbond Multipurpose adhesive and Z100 composite resin. After dissolution of dental structures, the restorations were observed with a scanning ele ctron microscope. No morphologic differences were found be tween in vivo and in vitro specimens with either of the new dentinal adhesive systems tested. Short resin tags were often found in vivo, particularly at the cavity walls. Only a few areas in vivo had deep resin tags (longer than 100 um) and these were always at the cavity floor