Quintessence International, 02/2001

The introduction of pre-impregnated fiber-reinforced resin composites has provided the dental profession with the opportunity to fabricate and deliver adhesive, esthetic, and metal-free tooth replacements. Utilizing this technology, a prefabricated fiber-reinforced resin composite fixed partial denture prototype that allows rapid, cost-effective, and noninvasive fixed tooth replacement for single anterior teeth has been developed. Ideal situations for this type of service include: a fixed replacement following tooth loss from trauma; a fixed tooth replacement in medically compromised patients who cannot sit for extended periods of time or have local anesthesia; periodontally compromised abutments; a fixed space maintainer following orthodontic movement; and a fixed provisional during the post implant healing phase prior to loading. This article describes the framework construction and placement protocol for the prefabricated fiber-reinforced resin composite fixed partial denture.

Objective: Tooth sensitivity is a common side effect associated with tooth whitening. The purpose of this study was to determine if bleaching tray delivery of potassium nitrate-fluoride reduces bleaching sensitivity enough to allow continuation of whitening treatment. Method and materials: Thirty patients were enrolled in a university-approved clinical study and had their teeth bleached at night with 10% carbamide peroxide in a custom-fitted tray. The bleaching tray was a rigid experimental design for which sensitivity was expected. If tooth sensitivity was experienced, the patient applied a gel containing 5% potassium nitrate and 1,000 ppm sodium fluoride in the bleaching tray for various time periods. Log forms were collected upon completion of bleaching, and patient interviews were used to compare effects of the gel before and after sensitivity treatment. Results: Sixteen out of 30 patients experienced tooth sensitivity. Of those 16 patients, 12 used the gel, and 11 of the 12 reported a reduction in sensitivity. Treatment times ranged from 10 minutes before bleaching to 30 minutes before and after. The number of applications ranged from one to continuous use. Some patients were able to continue bleaching after one gel application with no subsequent sensitivity. Other patients were unable to continue bleaching unless they continued using the gel. The incidence of tooth sensitivity (53%) reported in this study is consistent with sensitivity reported in studies using semi-rigid custom-fitted trays made from stone casts with a nonscalloped, nonreservoir design. Conclusion: The use of a 5% potassium nitrate-fluoride gel applied in the tray as needed for tooth sensitivity associated with nightguard vital bleaching can reduce sensitivity in a majority of patients and allow most patients to continue bleaching to completion.

Objective: The purpose of this study was to photoelastically evaluate the effects of cervical root lesions and their restoration on stress distribution in periodontally compromised teeth. Method and materials: Three-dimensional composite photoelastic models of a maxillary first premolar with buccal cervical root lesions were fabricated. Two different lesion configurations, wedge- and shallow saucer-shaped, at 20% alveolar bone height reduction were tested. A 35% reduction model was given a wedge-shaped lesion. The lesions were restored with microfine resin composite. Vertical loads of 7.5 lbs were applied to the unrestored and restored models at the tip of the buccal cusp and the tip of the lingual cusp. The resulting stresses within the tooth models were monitored and recorded photographically in the field of a circular polariscope arrangement. Results: For buccal cusp loading of the unrestored models, stress concentrated at the apex of the lesion regardless of the lesion shape or periodontal support conditions. The highest stress concentration was observed around the apex of the wedge-shaped lesion on the 35% reduction model. Restoring the lesions changed stress distribution. Restoration of the lesions resulted in a marked stress reduction at the lesion apex. Stress along the gingival restoration-model interface was characteristic for the restored situation. The interfacial stress followed the contour of the restoration most closely for the wedge-shaped lesion on the 20% support reduction model. Conclusion: The shape and dimension of the lesion as well as periodontal support status has considerable influence on stress distribution, especially around the lesion, restored or not restored.

Objectives: The combination of an individually cast core and a prefabricated metal post is one of the many techniques to restore endodontically treated teeth. The surface characteristics of commercially available posts vary considerably and likely influence retention. In this study, the surface configuration of 11 castable prefabricated post systems and their retention at the post-cement interface were investigated. Method and materials: Scanning electron microscopic photos were made to assess surfaces of the posts. Etchant residues or applied surface layers were also analyzed with an electron beam microprobe. For the retention measurements, 6 posts from each system were cemented in artificial root canals with a zinc phosphate cement. Retention was measured on a universal testing machine. Results: Analysis of variance and the Ryan-Einot-Gabriel-Welsch F test revealed significant differences in retention between posts; these differences were related to the microstructure of the surfaces of the posts. In general, the coarser the surfaces, the better the retention. Gold plating of the etched surface for one manufacturer resulted in less retention compared to posts of the same type and size that were not plated. Conclusion: The surface configuration of a post could be an important factor when selecting a prefabricated post system.

Objective: It has been suggested that the oral cavity and dental plaque might be a reservoir for Helicobacter pylori (Hp). In this study, our aims were to detect the prevalence of Hp colonization in dental plaque and tongue scrapings of patients with chronic gastritis and to investigate the effect of systemic treatment upon this colonization and eradication of Hp from gastric mucosa. Method and materials: Eighty-one patients (49 men, 32 women) were included in the study. Dental plaque and tongue scraping specimens were obtained and assessed with Campylobacter-like organism (CLO) test, prior to endoscopic examination. By endoscopy, 2 antral and 1 corpus biopsy samples were taken for histologic examination, and 1 antral biopsy sample was taken for CLO test examination. Results: Chronic gastritis was diagnosed in 63 (77.7%) of 81 patients. Dental plaque samples of 64 (79%) patients and tongue scraping samples of 48 (59.2%) patients were urease positive. Of the 63 patients with chronic gastritis, dental plaque and tongue scrapings were urease positive in 52 (83%) and 37 (59%) patients, respectively. After 14 days of triple drug therapy (omeprazole, clarithromycin, and amoxicillin), Hp was eradicated from the gastric mucosa of almost all of the patients, whereas no changes were detected in dental plaque and tongue scrapings by CLO test examination. Conclusion: Helicobacter pylori colonization, which seemed to be high in dental plaque and on the tongue, might play an important role in the pathogenesis of the reinfection process. In order to eradicate Hp from both the oral cavity and the gastric mucosa, studies should be performed to assess the effects of plaque control procedures in addition to present treatment modalities.

General dentists, as well as pediatric dentists, treat many children. Behavior management for children is an integral component of pediatric dental practice. Behavior management techniques have been developed based on empirical evidence indicating the importance of social learning theory to change both the causes and consequences of negative behaviors. This paper addresses the theoretical basis of current approaches in guiding children's behavior during dental settings. The relevance of the theoretical areas to the day-to-day treatment of the patient is emphasized.

Objective: The purpose of this in vitro study was to determine the microtensile bond strengths (µTBS) of 3 dental adhesives when applied to dentin decalcified with ethylenediaminetetraacetic acid (EDTA). The null hypothesis tested was that the removal of calcium from dentin would not influence the bond strengths. Method and materials: Eighteen extracted human molars were cut in 2 equal halves. One half served as the control, having no EDTA treatment, while the other half was assigned to 1 of 3 periods (1 hour, 24 hours, or 100 hours) of decalcificatioin with buffered 0.5 mol/L EDTA. Middle dentin was bonded with 1 of 3 dentin adhesive groups: a self-etching primer, Clearfil SE Bond (SE); an acetone-based total-etch adhesive, Prime&Bond NT (NT); and an ethanol- and water-based total-etch adhesive, Single Bond (SB). The specimens were restored with Z-250 resin composite and sectioned in 0.9 ± 0.2 mm2 sticks that were tested in tensile mode. Results: For each adhesive, the control group (not decalcified) resulted in statistically higher bond strengths than the treatment groups. For specimens that were not decalcified, SE and SB had statistically similar bond strengths, but both resulted in statistically higher bond strengths than NT. For specimens decalcified for 1 hour, SE resulted in statistically higher bond strengths than either SB or NT, which were ranked in the same statistical group. SE was the only dentin adhesive to result in measurable µTBS after decalcification with EDTA for 24 hours, while SB/24 hour and NT/24 hour specimens debonded spontaneously prior to testing. All the specimens treated with EDTA for 100 hours debonded prior to testing. Conclusion: Three conclusions were drawn: (1) All 3 adhesive systems included in this project bonded significantly better to calcified than to decalcified dentin, regardless of their composition; (2) The self-etching primer-based adhesive ranked consistently equal to or better than the 2 total-etch-based adhesives, regardless of the EDTA decalcification time; and (3) Removal of calcium may be more detrimental for adhesives that rely on dentin acid etching than for adhesives based on self-etching primers.

Objectives: The purpose of this initial study was to evaluate the effects of both a sonic and a mechanical toothbrush versus the effects of no treatment on depth of subgingival penetration of epithelial and tooth-associated bacteria. Method and materials: Eight adult subjects exhibiting advanced chronic periodontitis with at least 3 single-rooted teeth that were in separate sextants with facial pockets >= 4 mm and = 8 mm and that required extraction constituted the experimental sample. Teeth were either subjected to 15 seconds of brushing with a mechanical toothbrush or a sonic toothbrush or left untreated. The test tooth and the associated soft tissue wall of the periodontal pocket were removed as a single unit. Samples were processed and coded for blind examination by scanning electron microscopy. Distributional and morphologic characteristics of dominant bacteria with specific emphasis on spirochetes were evaluated for both epithelial- and tooth-associated plaque. Results: No differences were found in morphotypes or distributional and aggregational characteristics of epithelial-associated microbes in the 1- to 3-mm subgingival zone between the mechanical and sonic toothbrush-treated groups and the control group. Both toothbrush groups featured disruption of microbes that extended up to 1 mm subgingivally. Root surfaces on the sonic-treated samples appeared plaque-free at low magnification; however, at 4,700x, a thin layer of mixed morphotypes and intact spirochetes was found supragingivally and slightly subgingivally. In comparison, mechanical brush samples featured incompletely removed plaque, both supragingivally and subgingivally, with intact spirochetes present on subgingival root surfaces. Conclusion: Results suggest similar effects for both sonic and mechanical toothbrushes on epithelial- and tooth-associated bacterial plaque in periodontal pockets and adjacent root surfaces that extend up to 1 mm subgingivally. Further, the presence of intact subgingival spirochetes suggests limited exposure to acoustical or mechanical energy from the toothbrushes evaluated.

Dr Jack Whittaker grew up in Bowling Green, Ohio, in a family atmosphere that was dominated by sports and nurtured by sportsmanship. Planning on dentistry since high school, Jack graduated from The Ohio State University dental school and in 1970 opened a general dentistry practice in Bowling Green, where he now practices pediatric dentistry. From the earliest days of his practice, Jack has treated low-reimbursement Medicaid patients. Eventually realizing that most of his colleagues were not doing likewise, he became concerned that children who needed care were not getting it. As a result, he began a long process to effect change. Within the profession, he campaigned to encourage both generalists and specialists to accept Medicaid patients. Simultaneously, he forged a successful relationship with an influential elected official in state government that brought about a significant increase in the rate of Medicaid reimbursement to dentists. Apart from his practice, Jack has expressed his concern for children through coaching and off-the-field leadership in baseball, football, and ice hockey.