Quintessence International, 07/2005

Objective: Total dehydration of acid-etched dentin is known to cause the collapse of collagen fiber, which leads to poor hybridization. Dentin-bonding systems with water as a solvent are found to rehydrate the collapsed collagen. Acetone-based adhesives are found to compete with moisture, and the acetone carries the resin deep into the dentin. The question arises whether to dry the dentin and use a water-based adhesive, or to keep the dentin moist and use an acetone- or alcohol-based adhesive. The aim of this study was to compare different bonding systems and techniques to assess which is most successful. A confocal microscope was used to evaluate the amount of hybrid layer formation and the depth of resin tag formation. Method and materials: Superficial occlusal dentin specimens from 120 noncarious, freshly extracted human premolars were used for the study. The dentin was etched using 36% phosphoric acid for 15 seconds and then rinsed. The specimens were then randomly divided into 4 groups for different drying procedures: group I: air-dried for 30 seconds; group II: air-dried for 3 seconds; group III: blotted dry; group IV: overwet. The specimens were further subdivided into 3 groups to be tested with different bonding systems: subgroup A: acetone-based adhesive (Prime & Bond NT); subgroup B: water-based adhesive (Syntac Single Component); subgroup C: water- and ethanol-based adhesive (Single Bond). The resulting resin-dentin interfaces were then examined and categorized via confocal microscopy, and relative values were assigned to each specimen. Results: Group IV (overwet) showed the lowest values, and the highest values were obtained in group III. The highest values were seen in group III, subgroup A (blotted dry, acetone-based bonding agent, Prime & Bond NT). Conclusion: Under these conditions, using these three bonding systems, maximum hybridization and resin tag formation was achieved using acetone-based adhesive on etched dentin kept moist by blot drying. Keywords: bulimia nervosa, eating disorders, galvano-ceramic restorations, metal-ceramic, rehabilitation

Objective: Total dehydration of acid-etched dentin is known to cause the collapse of collagen fiber, which leads to poor hybridization. Dentin-bonding systems with water as a solvent are found to rehydrate the collapsed collagen. Acetone-based adhesives are found to compete with moisture, and the acetone carries the resin deep into the dentin. The question arises whether to dry the dentin and use a water-based adhesive, or to keep the dentin moist and use an acetone- or alcohol-based adhesive. The aim of this study was to compare different bonding systems and techniques to assess which is most successful. A confocal microscope was used to evaluate the amount of hybrid layer formation and the depth of resin tag formation. Method and materials: Superficial occlusal dentin specimens from 120 noncarious, freshly extracted human premolars were used for the study. The dentin was etched using 36% phosphoric acid for 15 seconds and then rinsed. The specimens were then randomly divided into 4 groups for different drying procedures: group I: air-dried for 30 seconds; group II: air-dried for 3 seconds; group III: blotted dry; group IV: overwet. The specimens were further subdivided into 3 groups to be tested with different bonding systems: subgroup A: acetone-based adhesive (Prime & Bond NT); subgroup B: water-based adhesive (Syntac Single Component); subgroup C: water- and ethanol-based adhesive (Single Bond). The resulting resin-dentin interfaces were then examined and categorized via confocal microscopy, and relative values were assigned to each specimen. Results: Group IV (overwet) showed the lowest values, and the highest values were obtained in group III. The highest values were seen in group III, subgroup A (blotted dry, acetone-based bonding agent, Prime & Bond NT). Conclusion: Under these conditions, using these three bonding systems, maximum hybridization and resin tag formation was achieved using acetone-based adhesive on etched dentin kept moist by blot drying. Keywords: confocal microscope, dentin adhesives, dentin bonding, dry/wet bonding, hybridization, moist bonding, resin-dentin interface

Titanium is used for many dental applications and instruments, such as orthodontic wires, endodontic files, dental implants, and cast restorations. The popularity of titanium is primarily due to its good mechanical properties, its high corrosion resistance, and its excellent biocompatibility. A thorough review of the medical and dental literature reveals, however, that titanium can also cause chemical-biological interactions. Tissue discoloration and allergic reactions in patients who have come in contact with titanium have been reported. The biostability of titanium is becoming increasingly questioned. At the same time, new technologies and materials, such as high-performance ceramics, are emerging which could replace titanium in dentistry in the not-too-distant future. Keywords: allergies, α-case layer, biocompatibility, composition, corrosion, nonalloyed titanium

Objective: The efficacy of a topical application of hyaluronic acid (HA) was tested for treating gingivitis. Method and materials: Sixty nonsmoking outpatients in good general condition, with clinical signs of gingivitis, were included in the study. Forty patients (HA group, 20 men, 20 women; age: 32.8 ± 11.3 years) used a spray containing HA 5 times daily over a period of 1 week. The control group consisted of 20 patients (10 men, 10 women; age: 31.3 ± 9.3 years). The clinical parameters DMF-T (decayed, missed, filled teeth) index, approximal plaque index, sulcus bleeding index, papilla bleeding index, and gingival crevicular fluid were measured at baseline (T1), after 3 days (T2), and after 7 days (T3). Results: A reduction in the sulcus bleeding index of the HA group (T1: 72.9 ± 19.5%) to 50.3 ± 21.1% was noted at T2, and at T3 the sulcus bleeding index was 40.7 ± 23.0%. The papilla bleeding index values of the HA group were 1.6 at T1, 1.0 at T2, and 0.7 at T3. The gingival crevicular fluid showed significant reductions in the HA group. At T1 the recorded mean value was 16.3, at T2 it was 11.8, and at T3 it was 7.9. Only insignificant changes were observed in the respective indices of the control group. There were no significant alterations in the plaque values of either group throughout the study period. Conclusion: The results obtained by this study demonstrate that the topical application of an HA-containing preparation represents a potentially useful adjunct in the therapy of gingivitis, although its use does not diminish the need for plaque reduction as a primary therapeutic measure. Keywords: gingivitis, gingivitis therapy, hyaluronic acid

Objective: The purpose of this study was to determine the effectiveness of mineral trioxide aggregate and glass ionomer when placed coronally as double-sealing materials over gutta percha. Method and materials: Seventy extracted anterior teeth were cleaned, shaped, and obturated with gutta percha and Sealapex. After removing 4 mm of coronal gutta percha, the teeth were randomly divided into 3 groups. In two experimental groups of 30 teeth each, 4 mm of either mineral trioxide aggregate or glass ionomer was placed in the chamber over gutta percha. A positive control group of 5 teeth received no barrier. A negative control group of 5 teeth was covered completely with sticky wax. All teeth, except the negative controls, were covered with 2 layers of sticky wax except for the access openings. Teeth were immersed in Pelikan ink for 48 hours, and then were decalcified, dehydrated, and cleared. Leakage into the canals was measured in millimeters and statistically analyzed between the two experimental groups using the Mann-Whitney test. Results: Results showed that the glass ionomer group leaked significantly more than the mineral trioxide aggregate group (P .001). Conclusion: It was concluded from this study that mineral trioxide aggregate may be preferred over glass ionomer as a seal intracoronally following root canal treatment to prevent coronal microleakage. Keywords: coronal seal, coronal leakage, dye leakage, glass ionomer, mineral trioxide aggregate, root canal treatment

Burning mouth syndrome is a condition in which the patient perceives a sensation of intraoral burning, typically of the anterior tongue. This article presents a case report of a patient presenting for orofacial pain evaluation in whom ciguatera neurotoxin poisoning is diagnosed. The clinician should be aware of neurotoxin poisoning as a possible cause of symptoms of burning mouth, especially among patients who have recently traveled to a tropical area. Recognition of this condition in this case highlights the need for a detailed and accurate patient history. Keywords: burning mouth syndrome, ciguatera neurotoxin poisoning

Objective: The purpose of this in vitro study was to investigate the efficacy of EDTA gel preparation, associated with texapon detergent (EDTA-T), for removing the smear layer at human root surfaces. Method and materials: An experimental smear layer was produced by scaling using periodontal curettes, and the root surfaces were etched with the following concentrations of EDTA-T: 5%, 10%, 15%, 20%, 24%, and negative control (saline solution) for 1, 2, or 3 minutes using both passive and active methods. The surfaces were evaluated by scanning electron microscopy, and photomicrographs were evaluated in relation to smear removal. Results: All EDTA-T groups were more effective than the control group (P .0001). EDTA-T at 15% was more effective when applied by the passive method, although this difference was not observed for the active method. The active method was statistically better than the passive method (P .0001). Conclusion: The etching of the root surface with EDTA-T gel by active application, independently of the other factors evaluated, was effective for smear layer removal. Keywords: EDTA, periodontal diseases, periodontal therapy, scanning electron microscopy, smear layer, tooth root

Objectives: The purpose of the study was to compare children's reactions to inferior alveolar nerve injection with traditional syringe and periodontal ligament injection with a computerized device (Wand); and to assess the efficacy of the anesthesia and their reaction after treatment. Method and materials: Twenty-five children, aged 6 to 10 years, participated in the study. The contralateral primary mandibular second molars were treated in 2 separate visits with random use of either the Wand or traditional syringe injection. The pain perception levels for each step were assessed with Eland Color Scale during the preparation. A Mann-Whitney U test was performed to compare the results. The patients were asked their preference of technique after the treatment. Results: When pain was measured immediately after injection, the traditional syringe was found to be more painful than injections with the Wand (P .05). Pain scores with the Wand injections were found to be significantly (P .05) higher than those with traditional inferior alveolar nerve injections at the end of the restoration. The overwhelming majority of patients favored the periodontal ligament injection with the Wand. Conclusion: The Wand technique provided significantly lower pain scores during the periodontal ligament injection. However, the pain scores during the treatment were significantly higher compared with the inferior alveolar nerve injections. Most of the patients stated that they preferred the periodontal ligament injection with the Wand to the traditional inferior alveolar nerve injection. Keywords: Eland Color Scale, IAN injections, PDL injections, primary molars, pulp therapy, WAND

The removable implant-supported prosthesis is the treatment of choice in some clinical situations. Despite its technically demanding fabrication and the resultant high cost, the bar-latch overdenture provides stability and is easy for patients to manage. A case report illustrating the surgical and prosthetic procedures of this treatment option, including laboratory fabrication, is presented. Keywords: edentulism, implant-supported prosthesis, overdenture