Quintessence International, 09/1999

Objective: The purpose of this project was to evaluate the performance of a dentin adhesive system on carious and noncarious primary dentin in vivo. Method and materials: Forty-eight primary molars with carious lesions were randomly assigned to 2 different treatments: group 1 (control, n = 24) - All identifiable, irreversibly infected dentin was removed prior to the application of the bonding agent and restorative material; group 2 (experimental, n = 24) - Irreversibly infected dentin was partially removed prior to the application of the bonding agent and restorative material. The control and experimental teeth were clinically monitored every 3 months and evaluated 12 months after restoration. The teeth were extracted around the time of exfoliation and processed for scanning electron microscopy. Results: Retention rate, marginal integrity, and pulpal symptoms were identical in both groups. Radiographically, the radiolucent area associated with the experimental restorations did not increase with time in 75% of the cases. For the control group, the adhesive system formed a hybrid layer. In the experimental group, there was morphologic evidence of the formation of an acid-resistant 'altered hybrid layer.' An acid-resistant tissue, resulting from the interdiffusion of adhesive resin within the area of carious dentin, was observed adjacent to and under the altered hybrid layer. Conclusion: Application of an adhesive restorative system to irreversibly infected dentin did not affect the clinical performance of the restoration.

The introduction of an intraradicular composite reinforcing technique, in conjunction with the reestablishment of matching post canal spaces, has allowed compromised, root-filled teeth to be restored with functional, esthetic post crowns. This clinical case report suggests that reconstituted post canals, in accurately adapting to passive, parallel-sided, matching, and well-fitting posts, can enhance the retention of post crowns. Other factors of clinical importance relating to the resin-reinforced technique are discussed, including fracture resistance, depth of polymerization, dentin adhesion, polymerization shrinkage, and coronal microleakage.

Objective: The purpose of this study was to compare the esthetics of 3 resin-modified glass-ionomer materials and 1 polyacid-modified resin composite to the esthetics of a conventional glass-ionomer control material. Method and materials: One hundred eighty-seven Class V cervical restorations were observed clinically over 18 months. The esthetic index system that was used evaluated color match, translucency or opacity, and surface roughness. Results: The tested materials behaved very dissimilarly and inconsistently. In general, the esthetic results of the resin-modified glass-ionomer materials and the polyacid-modified resin composite were far from optimal. The esthetic appearance of restorations seriously deteriorated during clinical service, mainly because of discoloration of margins, changes in translucency and opacity, and rapidly appearing roughness or dullness on the surface. Both the resin-modified glass-ionomer materials and the polyacid-modified resin composite evaluated in this study performed better esthetically than did the conventional glass-ionomer material. Conclusion: Indications for these combination materials are limited to areas where esthetics is not a primary concern but where their ease of application may guarantee a more durable functional result.

In dentistry, the endoscope has generally been used to visualize inaccessible areas, eg, inside root canals or coronal surfaces of teeth; however, it has not been used in periodontally diseased lesions. In this study, a newly designed fine fiberscope (0.8- to 1.0-mm outer diameter) with an irrigation system was used to visualize root surfaces and periodontal tissues affected by periodontal disease. The fiberscope was inserted through fistulas, periodontal pockets, or root furcations in 5 patients to provide clear operational views without the obstruction of blood or soft tissues. The irrigation system of the endoscope effectively allowed differentiation of hard and soft tissues as well as restorative materials. The fiberscope system developed in this study was effective for diagnosis, for enhancing visualization for periodontal surgery, and for treating lesions such as fistulous tracts or furcation lesions.

Objectives: Concern has been expressed about the obvious aerosol cloud that is generated during air polishing of teeth. These concerns have included infection control, potential systemic effects, and environmental surface contamination associated with the particles of sodium bicarbonate powder, water, and patient-generated material. This in vitro study evaluated an aerosol reduction device designed for use during air polishing. Method and materials: Eight artificial teeth on a Dentoform model were polished with and without the aerosol reduction device. The polishing was performed within a plastic enclosure that had a grid on the sides. The water supply for the air polisher contained a 1% fluorescein solution. The aerosol contamination was determined by counting the number of squares that showed fluorescent spots under an ultraviolet light. Results:The mean contamination without the aerosol reduction device was 175.59 cm2. The mean contamination with the aerosol reduction device was 4.37 cm2, a greater than 97% reduction in aerosol contamination. Conclusion: The aerosol reduction device significantly decreased the contamination produced during air polishing.

The nasolabial cyst is classified as a nonodontogenic cyst and is the only nonodontogenic cyst to occur in soft tissue. The aim of this retrospective analysis was to gather demographic, clinical, radiographic, and histopathologic data on the nasolabial cysts described in the files of the Oral Pathology Laboratory of Minas Gerais University School of Dentistry. Fifteen cases were included in the analysis. The mean age of the patients at the time of diagnosis was 42 years, and there was a female predilection. All the cysts were asymptomatic. Pseudostratified columnar (respiratory) epithelium, alone or in combination with other types of epithelium, was present in all cysts. Recurrence was not observed after surgical excision.

Objective: The purpose of this study was to evaluate the frequency of the use of gloves and to assess the prevalence of glove-related symptoms in a sample of Italian dentists with a high occupational exposure to latex gloves. Method and materials: A 31-question instrument was mailed to all dentists (n = 550) practicing in the town of Bologna during 1994 to determine the type of procedures for which gloves were worn by dentists and the prevalence of self-reported glove-related symptoms. Results: Of the dentists who replied to the items (n = 160), 94% reported that they usually wear nonsterile latex examination gloves; and 46% reported that they wear surgical gloves, even if not exclusively. About 98% reported changing gloves after contact with each patient, and 14% reported using disinfectants to treat examination gloves. Of the 106 respondents claiming to use examination gloves for surgical activities, 79 (74%) reported wearing them for extractions. Sterile surgical gloves were reported to be mostly worn for implant placement (47%) and periodontal surgery (42%). There were 46 (29%) responses indicating glove-related problems; of those subjects, 14 (30%) reported having other allergies. Conclusion: The use of gloves is common in the sample of Italian dentists, and the choice between nonsterile examination gloves and sterile surgical gloves seems to be made appropriately.

Objective: This study evaluated the effect of preparation utilization and design, and addition of resin composite to the bonding interface, on the fracture resistance of reattached incisal fragments. Method and materials: Sixty bovine incisors were distributed among 1 control group and 5 experimental groups. Experimental specimens were sectioned 3.0 mm from the incisal edge with a 0.15-mm wafering blade at a 25-degree inclination apically in a faciolingual direction. Two groups received no further preparation. Specimens in the other 3 groups received either external bevels, internal bevels, or combined external and internal bevels. One preparationless group was reattached with dentin bonding agent alone. All other fragments were reattached with a dentin bonding agent/resin composite interface. After thermocycling and 4 weeks of bond weathering, specimens were sheared to failure in a universal testing machine. Results: No significant differences in fracture strength were observed among any of the experimental groups, yet each displayed significantly less resistance to fracture than the control group. Reattachment of fragments in all groups restored approximately one half or one third the fracture strength of the control teeth for crown or root fractures, respectively. Conclusion: Compared to the simple, expedient regimen of using a dentin bonding agent alone, nonconservative tooth modification and the addition of resin composite to the bonding interface did not increase resistance to fracture and thus provided no retentive advantage.