Cementoblastoma associated with a primary tooth: a rare pediatric lesion.

An intraosseous, slightly painful swelling was noted upon clinical examination of an eight-year-old girl. The swelling was of an unspecified duration and slow growing in nature. A radiopaque mass with a radiolucent periphery attached to the roots of the mandibular right second primary molar was noted on a periapical radiograph. The diagnosis of cementoblastoma was verified by the histologic assessment.

Prevention of dental disease. The role of the pediatrician.

Evidence increasingly suggests that to be successful in preventing dental disease, we must begin preventive interventions within the first year of life. Pediatricians are well positioned to begin this process with early assessment of oral health and provision of anticipatory guidance, including ensuring that patients establish a dental home in addition to their medical home. This article provides information that will enable pediatricians to assess caries risk and provide practical and effective advice to parents about preventing dental disease, including oral hygiene, diet, and fluoride recommendations.

4-Hydroxytamoxifen-induced cytotoxicity and bisphenol A: competition for estrogen receptors in human breast cancer cell lines.

Increasing concerns over the effects of environmental estrogens on wildlife and humans have highlighted the need for screening systems to assess potentially estrogenic effects of test compounds. As a result, in vitro screening methods such as cell proliferation assays using the estrogen-responsive human breast cancer cell line, MCF-7, have been developed. The present study describes an alternative in vitro approach for the assessment of such xenoestrogens, based on estrogenic rescue of MCF-7 cells from antiestrogen-induced cytotoxicity. This method measures the ability of various estrogenic compounds to compete with a known estrogen-receptor-mediated antihormonal drug, 4-hydroxytamoxifen, using the 1-[4,5-dimethylthiazol-2-yl]-3,5-diphenylformazan (MTT) assay to assess mitochondrial activity. Because 4-hydroxytamoxifen treatment of cells results in a dramatic decrease in mitochondrial dehydrogenase activity which is directly related to their estrogen-receptor content, inhibition of this effect with estrogenic compounds represents an estrogen-receptor interaction, or estrogenic rescue. The estrogenic compounds tested include a weak xenoestrogen, bisphenol A (BPA), and two biological estrogens, 17alpha- and 17beta-estradiol. Competitive inhibition of 4-hydroxytamoxifen-induced cytotoxicity by BPA was compared to that of the biological estrogens. The results indicate that the biological estrogens can successfully compete with the antiestrogen in a dose-dependent manner. In addition, the assay is sensitive enough to detect estrogenic rescue by even the very weak xenoestrogen, BPA, albeit at high BPA concentrations. This simple in vitro method could be used as an alternative or second-line screen for potential xenoestrogens.

Comparison of direct digital and conventional radiography for the detection of proximal surface caries in the mixed dentition.

PURPOSE: The aim of this study was to compare the performance of direct digital radiography and traditional dental radiography for the detection of proximal surface dental caries in the mixed dentition. METHODS: 15 quadrants of extracted teeth, arranged from the primary canine to permanent first molar, were imaged using direct digital (Schick Technologies, Long Island City, NY, USA) and conventional films (D-speed and E-speed Plus; Eastman Kodak Co., Rochester, NY, USA). Five pediatric dentists viewed the images and scored the 270 proximal surfaces for presence of caries on a 5 point scale and extent of caries on a 4 point scale. The teeth were sectioned and viewed microscopically to determine the gold standard. Receiver operating characteristic (ROC) analysis and analysis of variance (ANOVA) were used to evaluate the viewer's performance for detecting proximal caries using the 3 different image receptor types. RESULTS: Experienced examiners were significantly more accurate in diagnosis of proximal surface caries using either D-speed or E-speed Plus films than they were using the direct digital receptor. The mean areas under the ROC curve (Az) for the viewers were 0.7595 for D-speed film, 0.7557 for E-speed Plus film, and 0.5928 for the direct digital receptor. The results also indicated that selected viewers' accuracy increased when viewing the direct digital images a second time. CONCLUSION: CCD based direct digital radiography was not as accurate as conventional film images for the purpose of diagnosing proximal surface caries in the mixed dentition. However, the results imply that with increased experience, direct digital images may be as accurate as conventional film based images for diagnosis.

What parents should know about estrogen-like compounds in dental materials.

The use of pit and fissure sealants has been reported to increase exposure to xenoestrogens. Because these estrogen-mimics are suspected of having many deleterious effects in animals, and perhaps humans, several types of studies were undertaken by our Biocompatibility Group. We confirmed that bisphenol A (BPA) and bisphenol A dimethacrylate (BPA-DM) have proliferative effects in cells with high levels of estrogen receptors. However, BPA was not detected by our group in American-made sealants, and BPA-DM was detectable in only a few. In addition, the surface layer of the sealant can be treated to reduce the possibility of unpolymerized BPA-DM being left on the tooth. We believe it is important to reassure parents that their children are less likely to be exposed to BPA from sealants than from the ingestion of soft drinks or canned food.

Estrogenicity of bisphenol A and bisphenol A dimethacrylate in vitro.

Although pit and fissure sealants have been utilized extensively in dentistry as a way of preventing occlusal caries, results described by Olea et al. (1996) raised concerns about the safety of sealants and other resin-based dental materials due to the reported presence of bisphenol A (BPA) and its dimethacrylate ester (BPA-DM). Although the release of these compounds from dental materials has not been substantiated by two subsequent studies, we believed it was important to confirm or refute the report that BPA and BPA-DM have estrogenic activity in vitro. We grew breast cancer cells (MCF-7, T-47D, ZR-75-1) known to proliferate under estrogenic stimulation in phenol red-free DMEM containing human serum and concentrations of BPA or BPA-DM ranging from 10(-8)M to 5 x 10(-6)M. After 1 week, plates were harvested for crystal violet or sulforhodamine-B assays, and the optical densities of groups of treated cells were compared with values from control cells. At concentrations at or above 10(-6)M, both BPA and BPA-DM significantly increased cell proliferation (p < 0.05), comparable to the increase seen with 10(-9)M of estrogen. Flow cytometric methods demonstrated that these mitogenic effects occurred within 24 h of exposure to estrogen, BPA, or BPA-DM. The increase in DNA synthesis was analogous to that seen with estrogen stimulation. Thus, we confirmed that BPA and BPA-DM cause cell proliferation at micromolar concentrations that exceed the effective concentrations of estrogen by 1 to 10,000-fold.