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OBJECTIVE: The purpose of this study was to test the hypothesis that remineralized dentin lesions induced by glass ionomer are less vulnerable to subsequent acid challenge. METHOD AND MATERIALS: Baseline demineralized (BDe) lesions were created in 50 bovine dentin slices immersed for 3 weeks in acid solution. A resin-modified glass ionomer (RMGI) was applied to the specimens before immersion in salivalike solution to allow remineralization (Re) for 2 weeks (V2W) or 6 weeks (V6W). Resin-modifed glass ionomer was coated to block further ion release before a 3-week immersion in acid solution as a second demineralization (SDe). Control groups (C2W and C6W) were done simultaneously without RMGI. In another group, RMGI was left undisturbed (V2W+) to allow continuous ion release during SDe. Mineral content was converted from microradiographs, after BDe, Re, and SDe steps. Changes in mineral content were calculated and compared between groups. RESULTS: The remineralized surface zone was maintained after SDe, but the lesion body became deeper. Percentage of mineral loss from SDe was not significantly different between V2W and C2W (t test, P > .05). When remineralization was extended to 6 weeks, V6W showed significantly less mineral loss than C6W. Mineral loss was lowest when RMGI was not blocked (V2W+). CONCLUSION: Dentin lesions remineralized in the presence of RMGI maintained the highly mineralized surface zone when subjected to second demineralization. However, the remineralized surface zone could not prevent advance of the lesion body. The subsequent demineralization was markedly reduced by extending the remineralization period or by leaving the RMGI undisturbed to resume ion release. [ABSTRACT FROM AUTHOR]

Purpose: The purposes of this study were to: (1) quantify and compare permanent tooth development of cleft lip and palate (CLP) patients to age- and gender-matched controls; (2) relate these findings to cleft type and severity; and (3) examine delays in individual permanent maxillary teeth related to their proximity to the cleft. Methods: Standardized methods using panoramic radiographs were employed to stage dental development and dental age for 49 children with clefts and 49 matched controls. Data were analyzed with a mixed linear model. Results: Analyses indicated a correlation between delayed permanent tooth development and CLP with an overall delay of 0.52 years (P = .02) and with boys accounting for all the delay. No differences were found between subjects with unilateral or bilateral clefts. A nonsignificant trend was noted for greater delay in subjects with clefts of the primary and secondary palates vs primary palate alone. Teeth most often affected by the delay were maxillary first and second premolars and maxillary second molars. Conclusions: While permanent tooth development is delayed in cleft lip and palate patients, this delay is: found in boys only; is independent of the cleft type and severity; and is not correlated with proximity to the cleft. [ABSTRACT FROM AUTHOR]

Background: The authors conducted a study to test the hypothesis that light-curing regimens affect depth of cure of clear versus opaque sealants., Methods: The authors light-cured samples of one clear and two opaque sealants at 20 seconds, 0 millimeters; 40 seconds, 0 mm; and 40 seconds, 2.2 mm (n = 5 each). They assessed the depth of cure with Knoop hardness at 0.5-mm increments five minutes and one hour after curing. The authors used analysis of variance., Results: Curing regimens and sealant types affected the depth of cure. The clear sealant maintained a greater hardness than did the opaque sealants through a depth of 3 mm (P < .001). A 20-second duration reduced the depth of cure for all sealants (P < .001). The distance from the light source did not affect the cure depth of the clear sealant (P = .34), but it reduced the cure depth of the opaque sealants (P < .05). Sealant hardness increased significantly one hour after light curing (P < .001)., Conclusions: A clear sealant cured deeper than did opaque sealants. Curing duration is crucial to achieve an adequate depth of cure. A 20-second duration may not suffice. Light source distance affected the depth of cure for the opaque sealants, but not for the clear sealant with sufficient curing duration., Clinical Implications: The authors advocate a curing duration of longer than 20 seconds to ensure thorough polymerization at the interface between the sealant and tooth. Insufficient curing could contribute to failure of the sealants, especially the opaque sealants, under clinical conditions that restrict the light tip position.

Purpose: The purpose of this study was to determine family characteristics, beliefs, and habits that contribute to early and severe caries in young children in Canada., Methods: A survey was administered to: (1) parents of 139 children diagnosed with early childhood caries (ECC) in 5 pediatric dentistry practices in Canada over a 33-month period (group 1); and (2) parents of all normal referrals (carious and noncarious children) in one of the practices over a 3 month period (group 2). Group 2 prevented studying an exclusive or polarized population, and allowed direct comparison between children with decoy and without decoy. The survey responses were compared with caries rates in the children, determined by dental examination, to detect important correlations of family and child factors with the disease level. Chi-square and logistic regression analyses described the strength of the relationships., Results: Parent responses provided information on: (1) demographics; (2) economic status; (3) birth order; (4) parental education; (5) payment methods; (6) feeding and weaning history; (7) fluoride history; (8) food habits; (9) hygiene; (10) behavior; and (11) medication use. Caries presence and severe caries was linked to: (1) leaving the bottle with a child while sleeping; (2) having problems brushing a child's teeth; (3) prolonged holding of liquids in the mouth; and (4) being Caucasian. The authors did find that bottle use in general and having a difficult child were protective influences against decay., Conclusions: The factors providing the most caries risk are: (1) being left with a bottle while sleeping; (2) parents having problems brushing the child's teeth; (3) holding liquids in the mouth for prolonged times; and (4) ethnicity.

Background: This study investigated an operator's and pediatric patients' responses to chemo-mechanical caries removal (CMCR) versus the traditional method (TM) of caries removal using a handpiece and a round bur when treating dentinal-depth occlusal lesions with minimal enamel access in primary molars., Methods: Data were collected from 50 children at baseline and before, during and after caries removal using CMCR or TM. The subjects in the CMCR group were on average younger than the subjects in the TM group and had more deep lesions., Results: The operator rated CMCR as needing more clinical and technical effort and more total effort than TM. He was less satisfied with CMCR than with TM. Subjects in the CMCR group perceived the time needed for treatment as significantly longer than did the subjects in the TM group. Fear of the dentist decreased in subjects in the TM group from before to after the operative appointment, while it increased in subjects in the CMCR group., Conclusions: The authors found no direct advantage in using CMCR over using TM., Clinical Implications: CMCR cannot be recommended as an alternative to TM when treating dentinal depth occlusal lesions with minimal access in primary molars.

Background: The authors investigated the effectiveness of chemomechanical caries removal (CMCR) compared with the traditional method (TM) of caries removal using a round bur when treating dentinal-depth occlusal lesions with minimal enamel access in primary molars. The authors also compare CMCR with TM to determine if it had a higher efficacy and could be used more frequently without the subject's having to undergo local anesthesia., Methods: The authors collected data from 50 children during operative appointments at which caries was removed using one of the two methods., Results: Complete caries removal within 15 minutes was achieved in only 57.7 percent of the CMCR-treated teeth. In 42.3 percent of these teeth, residual caries was removed using TM. CMCR was almost eight times more time-consuming than was TM when used to excavate dentinal-depth occlusal lesions with minimal cavitation. There was no significant difference between CMCR and TM in the number of subjects who needed to undergo local anesthesia., Conclusions: The authors found no direct clinical advantage in using CMCR over using TM for treating occlusal dentinal lesions with minimal cavitation in pediatric patients.

This paper reviews key issues of sealant use and methodology and poses recommendations to inform the discussion toward a consensus statement by participants. A comprehensive review of sealant literature, including policy recommendations from previous conferences that reviewed best practices for sealant use, was completed. Building on previous review papers and on previous policy statements by dental and public health groups, this paper discusses key questions about sealant use in light of contemporary caries data and cost-benefit analyses. In addition, newest material advancements are reviewed to establish the next step in sealant improvement for young patients.

Purpose: The objectives of this study were to: (1) determine the geographic distribution of pediatric dentists in private practice across the United States; and (2) compare state-based pediatric dental practitioner-to-children ratios., Methods: Enumeration of pediatric dental practitioners was derived from the American Academy of Pediatric Dentistry's 2000-01 Membership Directory by including all active and fellow members who were in private practice in the United States. Population information for the 50 states and District of Columbia was obtained from Census 2000 data available on the US Census Bureau's Web site., Results: A total of 2,913 pediatric dentists were in private practice in the United States, with the largest number located in California (333), Texas (238), and New York (202), and the smallest number located in Maine (3) and North Dakota (4). There were 4.03 pediatric dental practitioners for every 100,000 US children younger than 18 years of age. Connecticut and Massachusetts had almost twice (7.7) as many pediatric dental practitioners per 100,000 children as the national average. On the other hand, Maine had only one fourth (1) the number of pediatric dental practitioners per 100,000 children as the national average., Conclusions: Marked differences exist between the various states in their pediatric dental practitioner-to-children ratio.

Purpose: The purpose of this 10-year, retrospective, cohort study was to evaluate the success of permanent molar sealants by comparing the effectiveness of sealants placed by dentists, dental hygienists, and dental assistants in a private dental practice, with all operators using an identical, standardized, application technique and 4-handed dentistry., Methods: From 810 patient records that met entry criteria, the long-term follow-up records of 3,194 permanent first molars were evaluated. Data were collected and evaluated by survival analyses methods for: (1) time to first failure (caries or restoration of the sealed surface); (2) fluoride history; (3) caries experience; (4) operator type; (5) behavior at sealant placement; (6) tooth type; (7) age at placement; and (8) patient gender., Results: Cumulative survival probability for 10 years in this practice was 87%, using Kaplan Meier analyses. The factors associated with an increased risk of failure included: (1) age (P<.001); (2) dmft (P<.003); (3) no fluoride (P<.001); (4) dentist (P<.001); and (5) registered dental assistant (P<.001). While all operator groups had success rates equal to or exceeding previous studies, dentists and registered dental assistants showed 3 times and 2 times the risk of failure, respectively, compared to the registered dental hygienists. The no-fluoride group showed almost twice the risk of failure as compared to the optimal fluoride group. Behavior showed a slightly higher risk of failure that approached significance. Age and dmft were highly significant, with slight increased risk of failure. Supplemental fluoride showed a protective effect, but this was marginally significant. Gender and tooth-type were not significant in this model. Major variations in success rates were observed in the dental assistant group, with 2 individuals accounting for most of the failures., Conclusions: This study supports delegation of sealant delivery to auxiliaries, since dental assistants and dental hygienists were equal to or better than the dentists in long-term sealant effectiveness.

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.

Purpose: To evaluate the 2-year clinical sealant success when using Prompt L-Pop (3M-ESPE), the first self-etching adhesive, as the sole etching and adhesive step prior to sealant placement., Methods: Patients ages 7-13 years with matched pairs of permanent molars needing sealants were enrolled into an ongoing clinical study of sealant success. First and/or second permanent molars were randomly assigned to control (sealant only after phosphoric acid etch) or Prompt plus sealant groups in a split-mouth, matched pair study design. Standard methods were used for sealant (Delton, Dentsply) placement, except for the Prompt group in which the self-etching adhesive was brushed on the surface, air thinned, followed by immediate placement of the sealant and polymerization. All sealants were placed using appropriate cotton-roll isolation and a dental assistant. Sealant scoring was done at 24 months using strict clinical criteria for failure, previously published, and photos of the sealed surfaces were archived on video., Results: Percentages of sealants scored as successful (no significant loss of material or need for repair) through 24 months were: (a) Occlusal sealants: Control = 61%, versus Prompt = 61%; (b) Bu/Lingual sealants: Control = 54%, versus Prompt = 62%; McNemar's Chi Square tests indicate no difference in success between the Prompt sealants and their matched controls (P > 0.80). Time of placement for sealants, timed from start of the etch step through polymerization, averaged 3.1 minutes for Control and 1.8 minutes for Prompt. We conclude that Prompt L-Pop self-etching adhesive is effective in bonding sealant to enamel and that the simplified method dramatically shortens treatment time and treatment complexity.

Purpose: This study was performed to assess retrospectively the clinical and radiographic success of indirect pulp treatment (IPT) on primary posterior teeth, and to compare the influence of caries risk, skills of the operator, and restorative material on the success of IPT., Methods: A retrospective review of records of patients treated with IPT in the pediatric dental clinic at The University of Michigan, School of Dentistry from July 1993 through July 1999 was completed in January 2000. Two hundred fifty-five records with IPT were reviewed, from which 132 patients met the inclusion criteria, with 187 primary posterior teeth treated with an IPT. The patients were followed clinically and radiographically for a time ranging between 2 weeks to 73 months. Data were analyzed using survival analysis methods., Results: The success of IPT was 95% (178/187 teeth), with only 9 failures. The 1-year probability of survival of each tooth was estimated to be 96% using an exponential survival model. The use of a base over a calcium hydroxide liner significantly increased the success rate of IPT (P = .0095). The use of a stainless steel crown (SSC) after an IPT was significantly more successful than the use of an amalgam (P=.026). IPT performed on primary first molars failed more frequently than on second primary molars (P = .045). There was no significant difference between maxillary and mandibular primary molars., Conclusions: Indirect pulp treatment is a successful technique and should be considered as an alternative pulp therapy procedure in deeply carious primary posterior teeth. The use of a base over the liner in addition to a SSC dramatically increases the success of an IPT.

This paper reviews key issues of sealant use and methodology and poses recommendations to inform the discussion toward a consensus statement by participants. A comprehensive review of sealant literature, including policy recommendations from previous conferences that reviewed best practices for sealant use, was completed. Building on the review paper by Simonsen and on previous policy statements by dental and public health groups, this paper discusses key questions about sealant use in light of contemporary caries data and cost-benefit analyses. In addition, newest material advancements are reviewed to establish the next step in sealant improvement for young patients.

Purpose: The purpose of this study was to determine if the application of 1% chlorhexidine-containing wax on primary molars during the period of eruption of the first permanent molars could prevent the transfer of certain oral flora, namely Streptococcus mutans, to the permanent molars., Methods: Fourteen children with a mean age of 6.5 years (7 males and 7 females) were assigned into two groups: a chlorhexidine group (n=9) in which 1% chlorhexidine-containing wax was painted on primary molars on one side of the mouth; and a placebo wax group (n=5) in which a similar wax, but without chlorhexidine, was painted on primary molars on the other side of the mouth. Baseline saliva samples and pooled plaque samples from the primary molars on both sides of the dentition were obtained from the two treatment groups. Following treatment, plaque samples from the occlusal fissures of the first permanent molars on both sides of the dentition were obtained. The levels of S.mutans and other members of the oral flora on the treated sides (chlorhexidine or placebo) were compared with those on the untreated sides., Results: The results showed that the proportions of S.mutans to S.sanguinis were significantly lower in the chlorhexidine-treated sides compared to the untreated (P=0.04) and in the chlorhexidine-treated patients compared to placebo (P=0.029)., Conclusions: Since lower mutans to sanguinis ratios have been associated with lower caries experience, treating primary molars with 1% chlorhexidine wax during eruption of permanent first molars may be a simple means for shifting the fissure flora of the permanent molars towards a more favorable balance.

Society's approach to children during the past half-century has changed dramatically, and a transformation of medical and hospital pediatric care has followed. Dentistry has been slower to incorporate sound, child-friendly approaches to care. Nonetheless, much has changed in dental practice pertaining to children. The regular involvement of parents in the surgical/therapeutic suite is one such change. Expanded communication to ensure informed consent for treatment as well as consent for type of management approach to children is the standard of care. Since sedation policies are becoming more complex, enhancing the skills of all dentists and staff members in the best methods of nonpharmacological child management will be essential in the next decades. Biobehavioral methods will gain prominence, along with better communication skills of the dental team. These changes will occur only if more time and resources are positioned to teach dental students, dentists, and staff the necessary skills. Emphasis must be placed on early, timely intervention; parental involvement; effective communication; cultural competence; and the "medical/dental home" concept as methods to reduce negative dental attitudes and behaviors of children.

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.

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.

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.

Purpose: The effect of a chlorhexidine varnish delivery system on the levels of selected oral microorganisms was evaluated in caries active pediatric patients, ages 4 to 12 years old., Methods: Forty-six patients were enrolled into the study when they had multiple carious surfaces and salivary mutans streptococci (MS) levels higher than 10(4) colony forming units (CFUs) per milliliter. This study incorporated a double-blind design and patients were randomly assigned to either the chlorhexidine treatment group or the placebo group. Complete-arch, vacuum-adapted mouthguards (0.02 in. polypropylene coping material) were custom fabricated and coated internally with either a 3.0% chlorhexidine varnish or a placebo varnish. Two pretreatment paraffin-stimulated saliva samples were obtained for culturing prior to varnish treatment. Saliva samples were also obtained immediately after treatment and once a month for up to three months after wearing the mouthguard appliances. Dental restorations were placed at most of these saliva collection visits. Mouthguards were reportedly worn for an average of 9.7 hours per night for approximately seven nights by 40 subjects (87%)., Results: After two months, and after three months, there was a significant reduction in MS levels immediately after the chlorhexidine varnish treatment. Total anaerobic and total facultative bacteria levels were not significantly affected., Conclusion: One week of nightly use of the chlorhexidine varnish mouthguard system is effective at reducing the number of MS in caries-active pediatric patients in the mixed and primary dentition for at least three months.

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.

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.

The literature suggest differences between primary and permanent teeth regarding the composition and morphology of the dentin. The purpose of this study was to compare the effect of two dentin conditioners on the micromorphology of the dentin surface of primary and permanent teeth. Human extracted and noncarious molars were divided into four groups and conditioned with either 10% phosphoric acid (All-Bond 2) or 10% maleic acid (Scotchbond Multi-Purpose) for different time periods. SEM photomicrographs (1500x) were taken from the conditioned dentin and evaluated blindly by three calibrated examiners. The results indicate that the smear layer was removed more easily from primary teeth than from permanent teeth (P = 0.0001), which suggests greater reactivity to acidic dentin conditioners. We also found that the longer the time of application of dentin conditioner the more smear layer is removed (P = 0.0094). In comparing primary and permanent dentin, the results of this study indicate that less time is required for appropriate acid conditioning of primary dentin surfaces. Such a differentiated protocol for bonding to primary tooth dentin results in surface morphological characteristics similar to those found in conditioned permanent teeth.

The purpose of this study was to determine the in vitro bond strengths of composite rebonded to stainless steel crown metal (SS) using five different bonding agents after composite to SS bond failure had been produced. The adhesive systems were applied to the failed bonds following the manufacturers' instructions and, as a control, composite was bonded to SS without using a bonding agent. Each group was then divided into two subgroups: mechanically prepared (MP), in which the SS was roughened by a diamond bur, and unprepared (NMP), in which no modification of the SS was done. ESPE VISIO-GEM composite was placed in a plastic mold and light cured to the treated SS. Samples were stored in water at 37 degrees C for 72 hr, thermocycled for 500 cycles between 5 and 55 degrees C, and mounted in an Instron Universal Testing Machine. Caulk's Adhesive System provided significantly higher rebond strength (228.97 +/- 106.9 kg/cm2) than the other materials, and mechanical surface preparation offered no significant advantages.

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.

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.

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.

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.

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.

The frequency of head, face, mouth, and neck injuries due to child maltreatment was investigated in a review of 1248 cases on file in the pediatrics office at Hennepin County Medical Center in Minneapolis, Minnesota, from January, 1985, to December, 1989. There were 485 boys (38.8%) and 763 girls (61.2%) examined. Physical abuse cases (41.0%) outnumbered sexual abuse (35.4%) and neglect episodes (23.6%). The gender ratio was distributed equally except in sexual abuse, where there were 4.7 girls for each boy examined. More than half of the children (52.9%) were in the 0-to-4 year age group. Considering all cases together, 37.5% presented with injuries to the head, face, mouth, and neck. However, that percentage doubled (75.5%) when physical abuse episodes were reviewed alone. The intraoral injuries seen were five tooth fractures, three tongue and tongue frenulum lacerations, two lip frenulum lacerations, 11 injuries to the oral mucosa, eight palatal lesions, two fractures of the mandible or maxilla, loose and missing teeth, and dental neglect. Despite the high frequency of injuries, no dentists examined children at the time of the hospital intake or referred children for suspicion of maltreatment in the population studied. The findings suggest the importance of involving dental professionals in identifying, reporting, and preventing child abuse and neglect.

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.

Oral streptococci may cause infective endocarditis in patients with susceptible cardiac disease after dental treatment. Multiple dental visits, each preceded by penicillin prophylaxis, may result in the unwanted development of resistant oral streptococci. This study was undertaken to determine whether resistant oral streptococci would develop after the repeated use of penicillin prophylaxis in healthy adults. Plaque samples were collected from 20 subjects on each Monday for 5 successive weeks. Each subject was administered 2 gm penicillin V followed by 1 gm 6 hours later (standard prophylaxis regimen of the American Heart Association), on three successive Mondays (weeks 2, 3, and 4). The total cultivable oral streptococci and penicillin-resistant oral streptococci were determined for each plaque sample, and representative colonies of resistant streptococci were speciated. During the study, there was a significant increase in the number of subjects who harbored penicillin-resistant oral streptococci. However, with the exception of one subject who had resistant streptococci throughout the study, the number of resistant strains represented only 0.0003% to 0.41% of the total cultivable oral streptococci.

The interacting effects of time of exposure and concentration as factors in cytotoxicity were compared for glutaraldehyde and formaldehyde. Cells from a human fibroblast cell line (WI-38) grown to confluence in 24-well trays were exposed to a range of concentrations of each agent, for periods of 4 to 24 hr. Cytotoxicity was measured by its effects on mitochondrial dehydrogenase activity, as assayed biochemically. Cytotoxic effects of formaldehyde occurred over a narrow concentration range from nontoxic to maximally toxic, and the range was little affected by time of exposure. In contrast, glutaraldehyde exerted its effect over a wider concentration range, and longer exposure times were necessary for maximal toxicity. The data suggest that long contact times of glutaraldehyde with dental pulp are necessary for maximum fixation. While 19% formaldehyde appeared to be more toxic than 2.5% glutaraldehyde in terms of serial dilution, little difference in cytotoxicity was observed when the data were calculated in terms of molar concentrations of the two agents.

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.

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.