Parental attitudes on restorative materials as factors influencing current use in pediatric dentistry.

PURPOSE: The purpose of this study was to determine pediatric dentists' current practices and the perceptions about parents' opinions and how those parental preferences regarding dental materials influence dentists' practices. METHODS: A questionnaire was sent to 500 randomly selected active members of the American Academy of Pediatric Dentistry. Twenty-five items queried demographics, use of restorative materials, perceptions of parents' attitudes towards materials, and dentists' reactions to parents' concerns. RESULTS: The survey response rate was 61%. Parental concerns about materials in decreasing order were: (1) esthetics; (2) cost; (3) toxicity; and (4) durability. Parents' greatest concerns about stainless steel crowns were: (1) esthetics; and (2) cost. Among respondents, 43% followed parental preferences when challenged, and 28% currently never use amalgam. Amalgam use and the dentists' perception of parental challenge were each related to the socioeconomic status of the practice population, with lower socioeconomic practices feeling less parental challenge than higher socioeconomic practices and being more likely to use amalgam than "white" filling materials (P = .001). CONCLUSIONS: Mercury concerns occur more frequently with higher than lower socioeconomic status parents (P = .002). Stainless steel crowns are challenged based on esthetics and cost. When confronted, many pediatric dentists (43%) follow parental preferences, even when that action is contrary to their initial clinical judgment.

Effect of adhesive systems and bevel on enamel margin integrity in primary and permanent teeth.

PURPOSE: This study compared the effectiveness of self-etch and total-etch adhesive systems in bonding to the beveled and nonbeveled margins of primary and permanent teeth. METHODS: This in vitro, factorial-designed study allowed evaluation of 3 factors: (1) tooth type; (2) presence of a bevel; and (3) adhesive type. Two preparations, each including a beveled and nonbeveled margin, were completed on buccal surfaces of 60 extracted molars (30 primary and 30 permanent). Preparations were randomly assigned to self-etch or a total-etch adhesive system and restored with resin composite. After thermocycling, teeth were stained with silver nitrate, sectioned, and measured for microleakage. Statistical analysis used a repeated measures analysis of variance. RESULTS: Beveled margins had less microleakage than nonbeveled margins for primary and permanent teeth (P < .001). Total-etch had less microleakage than self-etch adhesives on primary (53% less, P < .001) and on permanent teeth (22% less, P = .01). Self-etch had considerably more microleakage when enamel margins were not beveled. Comparably less microleakage, however, was found for total-etch and self-etch in restorations with beveled margins. CONCLUSIONS: Total-etch adhesive and beveled margins resulted in the least microleakage. Margin beveling has a greater effect in minimizing microleakage than the type of adhesive used.

Dental caries potential of liquid medications.

Cariogenicity of seven commonly prescribed liquid medications was studied. Sucrose content of the medications ranged from 0 to 70 gm/100 ml. Initial pH and buffering capacity were measured and found to vary widely among the medications. Intraoral microbial plaque pH changes were determined at intervals for 30 minutes following an oral rinse with each medication. These data were compared with plaque pH changes caused by rinsing with an established cariogenic challenge, 10% sucrose solution. Decreased plaque pH was caused by each medication tested. The extent and duration of the pH drop varied among the medications. Patterns of the pH curves are discussed in relation to sucrose content, endogenous pH, and buffering capacity of the medications. Intraoral pH response to several medications equaled or exceeded that seen when sucrose rinses alone were given. The findings are discussed in relation to dental caries-producing potential of long-term therapy with liquid medications, and two cases are presented that implicate liquid medications as a major etiologic factor leading to rampant dental decay. It is concluded that health practitioners should be aware of the sucrose content of pediatric medications. Patient education to ensure adequate oral clearance following each dose of medication is an essential first step in minimizing the risk of dental decay posed by long-term therapy with liquid medications.

A comparison of the antibacterial and cytotoxic effects of parachlorophenol.

The antibacterial and cytotoxic effects of parachlorophenol (as 35% camphorated PCP and 2% aqueous PCP) were compared directly, using the agar overlay technique. Human pulp fibroblasts and L929 cells were grown to confluence in 60-mm petri dishes. Bacterial suspensions (S. aureus, E. coli) in agar were poured as a thin layer in 60-mm petri dishes. All were overlaid with agar. Cells were exposed to medicament via filter paper discs placed on the agar surface. After 24 hours, the zone of cell lysis (fibroblasts) or inhibition of bacterial growth was measured as diameter in mm. A dose-response relationship was observed for both fibroblasts and bacteria. The zone of inhibition for fibroblasts was larger than that for bacteria, indicating that the cytotoxicity of parachlorophenol exceeds its antibacterial activity.

Improved sealant retention with bonding agents: a clinical study of two-bottle and single-bottle systems.

Recent in vitro work and a short clinical study suggest that adding a bonding agent layer between sealant and saliva-contaminated enamel allows for adequate bond strength and retention of resin sealants and may improve success of all sealant applications. This five-year clinical study scored 617 occlusal and 441 buccal/lingual molar sealants, with use of a split-mouth design, with half receiving sealant alone and half bonding agent plus sealant. Treatment effects and potential risk factors for sealant failure were tested by means of a Cox regression model. Three bonding agent groups were analyzed for treatment effect: Tenure primer, Scotchbond Multi-Purpose, and 3 single-bottle dentin bonding agents as a third group. The single-bottle group was successful in reducing risk of sealant failure, with a hazard ratio (HR) of 0.53 (p = 0.014) for occlusal and 0.35 (p = 0.006) for buccal/lingual sealants. Scotchbond was detrimental to occlusal sealant success, with a HR of 2.96 (p = 0.0003). Tenure primer was neutral, showing HRs close to 1.0. Variables that affected success differed between occlusal and buccal/lingual sealants, suggesting that failures on these two surfaces may be dependent upon differing factors. Early eruption stage was a significant risk factor for both surfaces (HR = 2.91, p = 0.00001, occlusal; and HR = 1.52, p = 0.015, buccal/lingual). Behavior (HR = 1.96, p = 0.0007), salivary problems (HR = 1.73, p = 0.002), and visually apparent variations in enamel (HR = 1.51, p = 0.018) were significant risk factors for occlusal sealants only. In addition to completing detailed analyses of risk factors for sealant survival, this study shows that single-bottle bonding agents protect sealant survival, yielding half the usual risk of failure for occlusal sealants and one-third the risk of failure for buccal/lingual sealants.

Dentin bonding: SEM comparison of the resin-dentin interface in primary and permanent teeth.

Previous studies have suggested minor differences between primary and permanent teeth in terms of dentin composition and morphology. Other reports indicated lower bond strengths of resin composites to dentin of primary teeth compared with dentin of permanent teeth; however, no information is available regarding differences in the micromorphology of the resin-dentin interface that may explain these lower bond strengths. Therefore, the purpose of the present study was to compare primary and permanent teeth in terms of the thickness of the hybrid layer developed with two bonding systems. Our hypothesis was that bonding differences previously reported between primary and permanent dentin would be reflected in hybrid layer differences observable in SEM analyses. Twenty human extracted and non-carious teeth were divided into 4 groups: 5 primary and 5 permanent teeth restored with All-Bond 2/Bisfil P system; and 5 primary and 5 permanent teeth restored with Scotchbond Multi-Purpose/Z100. The sample area available on each tooth was divided for the two dentin conditioning times (7 and 15 sec). Measurements of hybrid layer thickness were performed by means of SEM at x13,000. The results of this study indicated that the hybrid layer produced is significantly thicker in primary than in permanent teeth (p = 0.0001), suggesting that primary tooth dentin is more reactive to acid conditioning. No difference was observed in the hybrid layers produced by the two adhesive systems (p = 0.7920). The increased thickness of the hybrid layer in primary teeth (25 to 30%) and the subsequent lack of complete penetration of adhesive resin into previously demineralized dentin may contribute to the lower bond strengths to primary dentin reported in the literature. If a narrower hybrid layer more uniformly infused with resin is the goal of dentin bonding, it is concluded that a differentiated protocol for bonding to primary dentin (with shorter time for dentin conditioning) can be used as a means to reproduce the hybrid layer thickness seen in permanent teeth.

Amelogenin p.M1T and p.W4S mutations underlying hypoplastic X-linked amelogenesis imperfecta.

Mutations in the human amelogenin gene (AMELX, Xp22.3) cause a phenotypically diverse set of inherited enamel malformations. We hypothesize that the effects of specific mutations on amelogenin protein structure and expression will correlate with the enamel phenotype, clarify amelogenin structure/function relationships, and improve the clinical diagnosis of X-linked amelogenesis imperfecta (AI). We have identified two kindreds with X-linked AI and characterized the AMELX mutations underlying their AI phenotypes. The two missense mutations are both in exon 2 and affect the translation initiation codon and/or the secretion of amelogenin (p.M1T and p.W4S), resulting in hypoplastic enamel. Primary anterior teeth from affected females with the p.M1T mutation were characterized by light and scanning electron microscopy. The thin enamel had defective prism organization, and the surface was rough and pitted. Dentin was normal. The severity of the enamel phenotype correlated with the predicted effects of the mutations on amelogenin expression and secretion.

Doubling time alpha-aminoisobutyrate transport and calcium exchange in cultured fibroblasts from cystic fibrosis and control subjects.

Population doubling time, kinetics of transport of alpha-aminoisobutyrate (AIB) and calcium (Ca) exchange were studied in skin fibroblast monolayers obtained from 5 subjects with cystic fibrosis (CF) and 5 age- and sex-matched controls. Population doubling time as estimated from cell count, protein and DNA was no different in the two groups. KM, Vmax, maximal uptake and time of half maximal uptake of AIB were no different in the two groups. Intracellular Ca pool size based on exchange of 45Ca with unlabelled Ca was significantly greater in monolayers from CF subjects.

The calcium abnormality in cystic fibrosis mitochondria: relative role of respiration and ATP hydrolysis.

Calcium uptake by mitochondria isolated from skin fibroblasts of patients with cystic fibrosis and controls was studied in the presence and absence of inhibitors. Since mitochondrial calcium accumulation may be supported by ATP hydrolysis or respiration, inhibitors of each were used to characterize the basis of previously described alterations in calcium uptake by mitochondria from patients with cystic fibrosis. Calcium uptake measurements under the influence of oligomycin and antimycin A suggest that the increased calcium uptake by mitochondria from patients with cystic fibrosis is related to altered respiratory system activity. Binding constants of calcium to the carrier system in mitochondria were not different between genotypes.

Differential sensitivity of normal human pulp and transformed mouse fibroblasts to cytotoxic challenge.

Six different lines of diploid cells from human pulp and one commonly used transformed-cell line, L929 (a continuous fibroblast line of mouse lung connective tissue origin), were challenged by sera changes, an agar-overlay toxicity test and transfilter-histochemistry-toxicity test. The normal diploid cells showed greater sensitivity than transformed cells in each test. Although a different parameter of cell toxicity was measured in each test, the data indicate greater toxic response in diploid cells by all measurements. These normal diploid human cells are more appropriate cells for toxicity testing materials for human use.

Water consumption and nursing characteristics of infants by race and ethnicity.

OBJECTIVES: The purpose of this project was to determine racial/ethnic differences in water consumption levels and nursing habits of children younger than 2 years old. METHODS: Data from the 1994-96 Continuing Survey of Food intakes by individuals (CSFII) were used for these analyses. Water consumption and breast-feeding data on 946 children younger than 2 years old were used. RESULTS: For black non-Hispanic children younger than 2 years old (n = 121), 5.3 percent of the children were currently being breast fed. This percentage was less than that seen in other racial/ethnic groups. For white non-Hispanic children (n = 620), this percentage was 10.8 percent; for Hispanic children (n = 146), 12.2 percent; for "other" children, 18.5 percent (n = 59). Black non-Hispanic children had the highest total water consumption (128.6 ml/kg/day) among all groups, white non-Hispanic had the lowest (113.2 ml/kg/day). These differences were not statistically significant in multivariate regression modeling. Black non-Hispanic children also drank more tap water (21.3 ml/kg/day) than white non-Hispanic children (12.7 ml/kg/day) and Hispanic children (14.9 ml/kg/day). The difference was statistically significant in multivariate regression modeling. CONCLUSIONS: The differences in breast feeding and water consumption observed among black children younger than 2 years of age could be a factor in the observed higher levels of fluorosis in black children compared to other children.

Retaining sealant on salivary contaminated enamel.

A two-year clinical study comparing sealants done with intentional salivary contamination shows that sealant retention is possible on wet enamel if a bonding agent is used between enamel and sealant. Dental material research implications and clinical possibilities are discussed.

Use of one-bottle adhesive as an intermediate bonding layer to reduce sealant microleakage on saliva-contaminated enamel.

PURPOSE: To evaluate the influence of three different adhesives, each used as an intermediary layer, on microleakage of sealants applied under condition of salivary contamination. MATERIALS AND METHODS: Six different experimental conditions were compared, 3 with adhesives and 3 without. After prophylaxis and acid etching of enamel, salivary contamination was placed for 10 s. In Group SC the sealant was applied after saliva without bonding agent and then light-cured. In Group SCA, after saliva, the surface was air dried, and then the sealant was applied and cured. In Groups ScB, SB and PB, a bonding agent (Scotchbond Dual Cure/3M, Single Bond/3M and Prime & Bond 2.1/Dentsply, respectively) was applied after the saliva and prior to the sealant application and curing. After storage in distilled water at 37 degrees C for 24 hrs, the teeth were submitted to 500 thermal cycles (5 degrees C and 55 degrees C), and silver nitrate was used as a leakage tracer. Leakage data were collected on cross sections as percentage of total enamel-sealant interface length. Representative samples were evaluated under SEM. RESULTS: Sealants placed on contaminated enamel with no bonding agent showed extensive microleakage (94.27% in SC; 42.65% in SCA). The SEM revealed gaps as wide as 20 microm in areas where silver nitrate leakage could be visualized. In contrast, all bonding agent groups showed leakage less than 6.9%. Placement of sealant with a dentin-bonding agent on contaminated enamel significantly reduced microleakage (P < 0.0001). The use of a bonding agent as an intermediary layer between enamel and sealant significantly reduced saliva's effect on sealant microleakage.

Reducing microleakage of sealants under salivary contamination: digital-image analysis evaluation.

This in vitro study investigated the effect of Scotchbond Dual Cure bonding agent on microleakage of sealant bonded to saliva-contaminated enamel. To determine microleakage, sealants were placed on previously extracted premolars, with or without bonding agent, in the presence or absence of salivary contamination. The curvilinear extent of microleakage was measured on the mesial and distal aspects of the sealant-enamel interface with a digital-image analyzer. The results revealed a statistically significant difference between the microleakage of the contamination/sealant group and the other three groups. The Scotchbond/sealant group exhibited slightly less leakage than did the sealant only and contamination/Scotchbond/sealant groups. Scanning electron microscopy was used to examine the enamel-material interface. Placement of Scotchbond between the sealant and enamel reduced microleakage of sealants applied under conditions of salivary contamination.

Home-use tooth bleaching agents: an in vitro study on quantitative effects on enamel, dentin, and cementum.

Studies on home-use bleaching agents containing carbamide or hydrogen peroxide demonstrate minimal topographic alteration and insignificant organic change to tooth material. This in vitro study evaluated the effects of a three-step commercial home-use bleaching agent on extracted human incisors over time. Each tooth was digitized by baseline and sequential profilometry and analyzed using computer software. Statistically significant volume loss was evident in cementum and dentin after simulations of 4 and 8 weeks of use.

Sealants and preventive restorations: review of effectiveness and clinical changes for improvement.

Sealants are effective caries-preventive agents to the extent they remain bonded to teeth. Preventive resin restorations (PRR) have a proven record, but are susceptible to failure as the overlying sealant fails. Careful analyses of studies reveal a measurable failure rate of sealants (5-10% per year) that must be addressed. Even under the best of circumstances, sealants fail. Therefore, dentistry (as well as third-party systems) must accept that sealants need vigilant recall and proper preventive maintenance. In addition, it is clear that cost-effective use of sealants will involve selective application on teeth with the greatest caries risk. Caries risk analysis of the patient as well as the tooth is an essential step in the treatment planning process. To improve sealant success, new material advances are suggested. Data from studies using an intermediate layer of dentin bonding agent between etched enamel and sealant show dramatic reduction of failure for sealants, particularly in instances of molars judged difficult to seal due to early stage of eruption.

Producing the next generation of professional educators in pediatric dentistry.

We will see an abundance of eager, well-prepared aspiring academic pediatric dentists only when the market forces make this decision more rational for the best and the brightest. Until then, our challenge is to show interested students the excitement and vitality of this career path through our own examples. Then, once those few are intrigued, it is incumbent upon the system to be prepared to foster their interest and help them improve their skills so they are prepared to be successful in the academic environment. In addition, supplementation of teaching efforts may come from other creative avenues. Potential additional sources are found in experienced clinicians as well as modern, media-based instructional packages.

Use of a bonding agent to reduce sealant sensitivity to moisture contamination: an in vitro study.

Moisture contamination of etched enamel during application of sealant is the most frequently cited reason for sealant failure. In preliminary studies, a dentin bonding agent (Scotchbond Dual Cure, 3M, St. Paul, MN) has been shown to bond adequately to etched enamel after salivary contamination. This study investigated bond strength in vitro, when a bonding agent was used beneath sealants under varied conditions of contamination. Five hundred bovine incisor crowns were separated randomly into eight groups. The enamel samples, etched for 60 sec with a 37% phosphoric acid gel, were contaminated with: 1) fresh whole saliva, air dried, 2) fresh whole saliva, left wet, or 3) moisture from a humidity chamber. All contamination conditions were tested for sealant bond strength with and without the bonding agent as an intermediate layer under the sealant. As controls, both sealant and bonding agent under sealant also were applied to clean etched enamel. Bond strength was measured using a universal testing machine. Data were analyzed using a two-way ANOVA. Under conditions of humidity or intact saliva, sealant alone showed significant reduction in bond strength (P less than 0.001). Bonding agent under sealant on wet contamination yielded bond strengths equivalent to the bond strength obtained when sealant was bonded directly to clean, etched enamel. Bonding agent used without contamination yielded bond strengths significantly greater than the bond strength obtained when using sealant alone without contamination (P less than 0.001). When the saliva was air dried onto the surface, there was no significant difference in bond strengths whether or not a bonding agent was used under the sealant.

A critical look at glutaraldehyde.

Glutaraldehyde has been proposed as an alternative to formocresol in pulpotomy treatment of primary teeth. Data regarding effects of the two medicaments have been discussed in the literature, but little attention has been given to critical comparisons concerning parameters of toxicity, mutagenicity, and systemic distribution of the two agents. This paper reviews previous data on systemic distribution of glutaraldehyde and formocresol from pulpotomy sites, as well as cytotoxicity and mutagenicity of the agents. Comparisons reveal little difference between the agents on the parameters reviewed. The authors question the rationale for glutaraldehyde as an alternative to formocresol.

Preparation and beliefs of graduates of a predoctoral infant oral health clinical program.

PURPOSE: The aim of this study is to evaluate the effects of a predoctoral clinical educational program on preparation and beliefs of participants related to infant oral health. METHODS: Questionnaires were constructed and mailed out to four classes of past dental students, two of which had attended the program. RESULTS: Significant differences were detected between groups regarding their feelings of preparation for examination procedures in children younger than 36 months and their beliefs regarding appropriate age of the initial dental visit.