Quintessence International, 05/2000

Objective: The purpose of this study was to evaluate the degree of color change, any rebound effect, and sensitivities associated with using 2 different concentrations of carbamide peroxide in vivo. Method and materials: Twenty-five subjects used 10% and 15% agents in trays for 14 days on different sides of their maxillary arches. Subjects returned in 3 days and at 1, 2, 3, and 6 weeks for evaluation of color change and rebound effect. Shade matching, photographic means, and a colorimeter were used for evaluation. Subjects self-reported gingival and tooth sensitivity on a scale of 1 (no sensitivity) to 5 (severe sensitivity). Results: After 2 weeks, change in L*, a*, b*, E*, and change in shade guide rank means for the 10% whitening agent were 6.50, -1.37, -4.63, 8.79, and -15.40, respectively; for the 15% agent, they were 8.72, -1.63, -5.90, 11.03, and -16.59, respectively. After 6 weeks, change in L*, a*, b*, E*, and change shade guide rank means for the 10% whitening agent were 3.04, -0.99, -3.19, 5.13, and -13.13, respectively; for the 15% agent, they were 3.48, -1.01, -3.60, 5.58, and -13.65, respectively. Means for gingival sensitivity were 1.18 and 1.21 for the 10% and 15% agents, respectively; means for tooth sensitivity were 1.21 and 1.26 for the 10% and 15% agents, respectively. Conclusion: All 3 methods of evaluation revealed a significant difference in the tooth lightness achieved by 10% and 15% products at 2 weeks but no significant difference at 6 weeks. No statistically significant difference was found in gingival or tooth sensitivity.

Esthetics is often compromised in patients who wear removable partial dentures with metal clasps placed on anterior teeth. Clinical procedures are presented for a new design of a removable partial denture that improves esthetics and function through a new dental attachment. The extracoronal resilient attachment system offers vertical resiliency and universal stress relief for use where a resilient prosthesis is indicated. The removable partial denture retained by these attachments provides esthetics, vertical resiliency, and easy replacement of worn attachments.

Objective: The purpose of this study was to compare the clinical efficacy of guided tissue regeneration with expanded polytetrafluoroethylene membranes to that of free gingival graft for treatment of adjacent facial gingival recession. Method and materials: Eight adjacent gingival recession sites with Miller class I or II defects containing at least a maxillary or mandibular canine were selected in 6 patients. Four recession sites in 3 patients were treated with guided tissue regeneration, and the other 4 sites in the remaining 3 patients were treated with free gingival graft. Probing depth, gingival recession, attachment level, width of keratinized gingiva, and root coverage were recorded before surgery (baseline) and 6 months and 1 year postoperatively. Results: Statistically significant improvements were found for gingival recession, attachment level, and root coverage from baseline to 6 months and 1 year postoperatively in both groups. Both procedures produced the same average reduction in gingival recession, gain in attachment level, and amount of root coverage after 1 year. Probing depths did not differ between groups throughout the study. The width of keratinized gingiva was significantly greater in the grafted group than in the guided tissue regeneration group. Conclusion: Both procedures produced the same average amount of root coverage, reduction in gingival recession, and gain in clinical attachment. The guided tissue regeneration procedure provided a better esthetic appearance without any difference in gingival color or architecture in cases of adjacent facial gingival recession.

Intrusion injuries commonly occur in the primary dentition. They can be described as luxation injuries resulting from an axially directed impact, which drives the tooth deeper into the alveolar socket. The impact results in compression of and damage to the periodontal ligament as well as injury to the pulp of the intruded incisor. In addition to rendering treatment to the intruded primary tooth, the dentist must also be aware of the possibility of an injury to the developing permanent teeth germs located in close proximity to the roots of the injured primary teeth. This review will discuss the characteristics, implications, and management of intrusion injuries of primary incisors. Keywords: intrusion, primary tooth, tooth injury, trauma

Luxation injuries to incisors, including intrusive displacement, occur with a high frequency in the primary dentition. Intrusion injuries are associated with damage to the pulpal and periodontal structures and possible fracture of the alveolar bone. The pulpal tissue of the intruded tooth sustains a severe shock during displacement, which may be reflected later by sequelae ranging from mild discoloration to pulpal necrosis and infection. Disintegration of pulpal tissue may result in periapical tissue inflammation, which in turn may induce developmental disturbances in the germ of the permanent successor tooth. Additionally, severe injury to the periodontal ligament during intrusion may lead to ankylosis of the primary incisor and consequently to delayed or ectopic eruption of its permanent successor. This article will review the possible sequelae affecting primary incisors following their intrusion. Keywords: discoloration, intrusion, primary tooth, pulpal necrosis, sequelae, tooth injury

Objective: The purpose of this study was to compare the marginal and internal adaptation of a non-gamma-2 amalgam and an ultrafine compact-filled light-cured composite in small to moderate-sized Class II restorations of conventional design. Method and materials: Fifty recently extracted human premolar and permanent molar teeth were selected for the study. The teeth were restored with either a non-gamma-2 amalgam alloy or a light-cured resin composite. The marginal adaptation of the restorative materials to the proximal surface outline form of each preparation was assessed. The mean percentages of perfect margins, marginal fissuring, and underfilled margins for the 2 restorative materials were recorded and statistically analyzed. Results: Both materials performed equally well in the buccal and lingual segments of the proximal box. At the cervical margin, the resin composite restorations showed a significantly greater number of imperfect margins and marginal fissuring. The incidence of underfilled margins was low for both restorative materials even at the cervical margin. Conclusion: Although there was some cause for concern about the marginal adaptation of the resin composite restorations along the cervical margin, the findings support contemporary teaching that small to moderately sized conventional Class II preparations may justifiably be restored with an appropriate resin composite.

Objective: The purpose of this study was to determine enamel and dentin bond strengths of a nonrinsing 'all-in-one' adhesive and of a nonrinsing conditioner combined with a 1-bottle adhesive. Method and materials: Specimens were obtained from 240 bovine teeth ground to expose enamel or dentin surfaces. Ten enamel and 10 dentin specimens were randomly assigned to each of 12 different combinations of adhesive system (Prompt L-Pop; no etch + Prime & Bond NT; NRC + Prime & Bond NT; 36% phosphoric acid + Prime & Bond NT; no etch + Prime & Bond 2.1; 36% phosphoric acid + Prime & Bond 2.1) and restorative material (resin composite; polyacid-modified resin composite ['compomer']). After the application of the adhesive system, a No. 5 gelatin capsule filled with the restorative material was seated against the enamel or dentin surface. After 24 hours in distilled water at 37°C, the specimens were thermocycled and the shear bond strengths were measured. Results: For resin composite, etching with phosphoric acid resulted in the highest bond strengths to enamel. For compomer, the highest enamel bond strengths were achieved with both phosphoric acid and Prompt L-Pop. Treating dentin with Prime & Bond NT without etching provided the highest mean bond strength for composite. For compomer, treating dentin with Prime & Bond NT resulted in the highest mean bond strengths, regardless of the conditioner. Conclusion: Compomer and resin composite exhibited statistically similar bond strengths. Bond strengths to dentin were significantly lower than those to enamel.