Predicting Dental Caries in Young Children in Primary Health Care Settings.

Young children need increased access to dental prevention and care. Targeting high caries risk children first helps meet this need. The objective of this study was to develop a parent-completed, easy-to-score, short, accurate caries risk tool for screening in primary health care settings to identify children at increased risk for cavities. A longitudinal, prospective, multisite, cohort study enrolled (primarily through primary health care settings) and followed 985 (out of 1,326) 1-y-old children and their primary caregivers (PCGs) until age 4. The PCG completed a 52-item self-administered questionnaire, and children were examined using the International Caries Detection and Assessment Criteria (ICDAS) at 12 ± 3 mo (baseline), 30 ± 3 mo (80% retention), and 48 ± 3 mo of age (74% retention). Cavitated caries lesion (dmfs = decayed, missing, and filled surfaces; d = ICDAS ≥3) experience at 4 y of age was assessed and tested for associations with questionnaire items using generalized estimating equation models applied to logistic regression. Multivariable analysis used backward model selection, with a limit of 10 items. At age 4, 24% of children had cavitated-level caries experience; 49% were female; 14% were Hispanic, 41% were White, 33% were Black, 2% were other, and 10% were multiracial; 58% enrolled in Medicaid; and 95% lived in urban communities. The age 4 multivariable prediction model, using age 1 responses (area under the receiver operating characteristic curve = 0.73), included the following significant (P < 0.001) variables (odds ratios): child participating in public assistance programs such as Medicaid (1.74), being non-White (1.80-1.96), born premature (1.48), not born by caesarean section (1.28), snacking on sugary snacks (3 or more/d, 2.22; 1-2/d or weekly, 1.55), PCG cleaning the pacifier with juice/soda/honey or sweet drink (2.17), PCG daily sharing/tasting food with child using same spoon/fork/glass (1.32), PCG brushing their teeth less than daily (2.72), PCG's gums bleeding daily when brushing or PCG having no teeth (1.83-2.00), and PCG having cavities/fillings/extractions in past 2 y (1.55). A 10-item caries risk tool at age 1 shows good agreement with cavitated-level caries experience by age 4.

Time Frame Analysis of Potassium Nitrate and Hydrogen Peroxide Diffusion into the Pulp Chamber.

OBJECTIVES: The primary objective of this study was to evaluate the effect of an innovative double-layer, single-application desensitizing/whitening technique of potassium nitrate (PN) and hydrogen peroxide (HP) diffusion at different time points. METHODS AND MATERIALS: Specimens were prepared from extracted caries-free human molars (n=90). Teeth were randomly assigned into four groups: Group A (HP CTRL) treated with 25% HP for 45 minutes, group B (PN CTRL) received a single-layer treatment of 5% PN for 45 minutes, group C received the double-layer treatment of 5% PN and 25% HP for 45 minutes, and group D received a 3% PN incorporated in a 40% HP gel for 45 minutes. PN and HP concentrations were measured at 5, 15, 30, and 45 minutes using standard chemical kits. Group comparisons were made using a repeated measures analysis of variance (ANOVA) test. Pairwise tests for differences in diffusion were done, using the Tukey adjustment of p values for multiple comparisons. A significance level of 5% was used. RESULTS: Group A showed no significant difference in HP diffusion rates between the 5- and 15-minute, 15- and 30-minute, or 30- and 45-minute time points; group D showed a similar trend; however, group C differed significantly at the 5-and 15-minute time points (p=0.0004), at the 15-and 30-minute time points (p=0.0026), and the 30- and 45-minute time points (p=0.0014). For PN diffusion, groups B and C had significantly different levels at the 15-, 30-, and 45-minute time points (p=0.0005, p=0.0002, and p<0.0001, respectively); and at the 15-, 30-, and 45-minute time points, groups D and C had significantly different PN diffusion (p=0.0327, p=0.0004, and p< 0.0001, respectively). Group C had significantly different PN diffusion at the 5- and 15-minute time points (p=0.0004), the 15- and 30-minute time points (p=0.0026), and at the 30- and 45-minute time points (p=0.0014). CONCLUSION: The double-layer technique showed superior diffusion of PN into the pulp chamber and did not affect the diffusion of HP when compared to other techniques. The double-layer technique may be suggested as an alternative tooth-whitening treatment to minimize tooth sensitivity.

Decline in Dental Fluorosis Severity during Adolescence: A Cohort Study.

Dental fluorosis occurs from overingestion of fluoride during tooth formation. However, there is little evidence in the literature on whether or how fluorosis prevalence and severity change over time after tooth eruption. Permanent dentition dental examinations were conducted at ages 9, 13, 17, and 23 as part of the Iowa Fluoride Study, which has followed a cohort from birth. Fluorosis was assessed using the Fluorosis Risk Index (FRI) and Russell's criteria for differential diagnosis. Measures of fluorosis severity at the person and tooth level were calculated: second highest FRI score at the person level (the maximum FRI score for each tooth was determined and the tooth with the second highest maximum FRI score was used) and highest FRI score at the tooth level. At both the person and tooth levels, a decline in mild to moderate fluorosis severity was observed across adolescence and young adulthood. Across each pair of adjacent examinations at the person level, for participants with a baseline second highest FRI of 0, most participants stayed at 0 (82% to 91%). Many participants with a baseline second highest FRI of 1 had a follow-up score of 0 (47% to 54%), while about a third had a follow-up score of 1 (34% to 38%), and a lower percentage had an increase to a score of 2 (9% to 15%). For participants with baseline second highest FRI score of 2, between 25% and 44% of participants had follow-up FRI scores each of 0, 1, and 2. Similar patterns were observed at the tooth level. These results were consistent with most of the existing, limited literature. Overall, fluorosis severity, which was initially mild to moderate, tended to decline during adolescence and young adulthood. Additional study of how this trend affects esthetic perceptions of fluorosis is warranted.

Efficacy of Direct Restorative Materials in Proximal Box Elevation on the Margin Quality and Fracture Resistance of Molars Restored With CAD/CAM Onlays.

PURPOSE: The purpose of this study was to investigate the effect of four direct restorative materials that can be used in the proximal box elevation (PBE) technique. METHODS AND MATERIALS: Seventy-five molar teeth were randomly assigned to one of five groups (n=15): type II glass ionomer (GI), type II resin-modified glass ionomer (RMGI), resin-based composite (RBC), bulk-fill (BF) resin-based composite, and a control with no box elevation procedure. Specimens were prepared for a standard mesio-occlusal-distal, computer-aided design/computer-aided manufactured (CAD-CAM) resin, nanoceramic onlay with mesial cervical margins located 1 mm above the cementoenamel junction (CEJ) and distal cervical margins located 2 mm below the CEJ. PBE was used to elevate the distal margins to 1 mm above the CEJ in all groups except the control group. For the control group the onlay margin was placed directly on the prepared distal tooth structure without PBE. A Lava Ultimate CAD/CAM resin, nanoceramic onlay restorative was manufactured and bonded on all specimens with RelyX Ultimate adhesive resin cement. The quality of the tooth-PBE material and PBE material-onlay interface was evaluated with scanning electron microscopy using epoxy resin replicas before and after cyclic loading (100,000 cycles, 1.2 Hz at 65N and 37°C). In addition to margin quality, the fracture resistance of each group was measured using a universal testing machine. Fracture pattern was recorded by visual examination. The Levene test for homogeneity and the Welch analysis of variance were completed for fracture resistance and margin quality. A χ2 test was completed for break mode. RESULTS: For dentin margins, a statistically significant difference was detected between the RMGI and control groups at baseline (p=0.0442). All other groups-GI, RBC, and BF-showed no difference from the control at baseline (p>0.05). No statistical significance was observed among groups for post-cyclic fatigue (p=0.8735). For onlay margins, no statistical significance was observed among groups for pre-cyclic fatigue, post-cyclic fatigue, or change (p=0.9713, p=0.528, p=0.4385, respectively). No significant difference was observed for the fracture resistance among groups or for the type of break by material used (p=0.1593, p=0.77, respectively). CONCLUSION: Within the parameters of this study, after mechanical fatigue, the materials used for PBE: RMGI, RBC, and BF, did not influence results in terms of margin quality and fracture resistance. Therefore, collective findings suggest that these materials might be suitable for PBE procedures. Nevertheless, clinical caution is recommended with any PBE procedure and further testing of GI materials is needed.

Service-learning's impact on dental students' attitude towards community service.

BACKGROUND: This study evaluated service-learning programme's impact on senior dental students' attitude towards community service at Virginia Commonwealth University (VCU) School of Dentistry. Experience gained through service-learning in dental school may positively impact dental students' attitude towards community service that will eventually lead into providing care to the underserved. MATERIALS AND METHODS: Two surveys (pre- and post-test) were administered to 105 senior dental students. For the first survey (post-test), seventy-six students of 105 responded and reported their attitude towards community service immediately after the service-learning programme completion. Three weeks later, 56 students of the 76 responded to the second survey (retrospective pre-test) and reported their recalled attitude prior to the programme retrospectively. RESULTS: A repeated-measure mixed-model analysis indicated that overall there was improvement between pre-test and post-test. Scales of connectedness, normative helping behaviour, benefits, career benefits and intention showed a significant pre-test and post-test difference. An association between attitude towards community service and student characteristics such as age, gender, ethnicity and volunteer activity was also examined. Only ethnicity showed an overall significant difference. White dental students appear to have a differing perception of the costs of community service. CONCLUSIONS: The service-learning programme at VCU School of Dentistry has positively impacted senior dental students' attitude towards community service.

Restoration of root surface caries in vulnerable elderly patients: a review of the literature.

The authors conducted a review to evaluate the current literature addressing root surface caries treatment in the vulnerable elderly, to identify any gaps in the literature that will need to be addressed in the future. The authors conducted a literature search of the electronic databases using MEDLINE, PubMed, to identify original clinical research articles regarding treatment of root caries lesions, with emphasis on research focused on the vulnerable elderly. Five articles were clinical studies of root caries restorations. Only one was conducted on a vulnerable elderly population. The results of the literature review show that there is a need for further studies addressing the restorative needs of the vulnerable elderly. With the aging of the American population, more research is needed to provide adequate care to this population. At this time, glass ionomers are a good treatment option.

The timing of subsequent treatment for teeth restored with large amalgams and crowns: factors related to the need for subsequent treatment.

Crowns and large amalgams protect structurally compromised teeth to various degrees in different situations. The aim of this investigation was to evaluate the survival of teeth with these two types of restorations and the factors associated with better outcomes. Retrospective administrative and chart data were used. Survival was defined and modeled as: (1) receipt of no treatment and (2) receipt of no catastrophic treatment over five- and 10-year periods. Analyses included: Kaplan-Meier survival curves, Log-Rank tests, and Cox proportional hazards regression modeling. Crowns survived longer with no treatment and with no catastrophic treatment; however, mandibular large amalgams were least likely to have survived with no treatment, and maxillary large amalgams were least likely to have survived with no catastrophic treatment. Having no adjacent teeth also decreased survival. Crowns survived longer than large amalgams, but factors such as arch type and the presence of adjacent teeth contributed to the survival of large amalgams.

Relationship between number of proximal contacts and survival of root canal treated teeth.

AIM: The present study tested the hypothesis that having two proximal contacts (PCs) at access is associated with improved survival of root canal treated (RCT) teeth, controlling for important presenting conditions, endodontic variables and restorative factors. METHODOLOGY: A treatment database at the University of Iowa College of Dentistry was used to identify permanent teeth undergoing obturation between 1 July 1985 and 31 December 1987. The list was restricted to teeth of patients with at least one dental visit in each two-year interval from 1985 to 1996, and a simple random sample of 280 patients (n = 400 teeth) was selected. Dental charts, radiographs, and computerized databases were examined to ascertain variables of interest and to verify study inclusion criteria. Kaplan-Meier survival estimates were generated for the 221 teeth satisfying study inclusion criteria. Multivariate Cox models were developed, with standard errors adjusted to account for clustering of teeth within patients. RESULTS: The final Cox model showed that teeth with < or =1 PC at access were lost at a rate three times that of teeth with 2 PCs (hazard ratio = 3.1; 95% confidence interval = 1.9-5.1), controlling for tooth type, presence of radiographic caries at access, and presence of a crown before or after obturation. CONCLUSIONS: Because RCT teeth with two PCs at access experienced substantially better survival than teeth with fewer than two PCs, the influence of PCs on prognosis should be recognized during treatment planning. Future research should employ prospective study designs, capture additional variables, and provide data to support endodontic treatment decisions.

Sequence and unusual 3' flanking region of the rat tRNA[Ser]Sec gene.

The single rat selenocysteine tRNA (tRNA[Ser]Sec) locus, including flanking sequence, was isolated by molecular cloning and its nucleotide (nt) sequence determined. In addition to the identification of likely regulatory elements 5' of this gene, this analysis also revealed a novel 3' repeat element consisting of three and a half repetitions of a 34-nt unit.

Concomitant chemoradiotherapy, neutron boost, and adjuvant chemotherapy for anaplastic astrocytoma and glioblastoma multiforme.

The survival rate for patients with malignant gliomas is poor. We describe the results of a prospective study using concomitant chemoradiotherapy, neutron boost, and adjuvant chemotherapy for patients with malignant gliomas. Forty-two patients with anaplastic astrocytoma (AA) and glioblastoma multiforme (GBM) were treated with postoperative photon radiation 45 Gy/25 fraction (fxs) with concomitant continuous intravenous infusion of 5-fluorouracil at 300 mg/m2/day x 5 days and hydroxyurea 0.5 g orally every 12 hr for 6 days for 5 consecutive weeks, followed by a neutron boost of 450 N cGy/6 fxs delivered twice weekly. Adjuvant chemotherapy with procarbazine, CCNU, and vincristine (PCV) was given up to 1 year or until tumor progression. Thirty-four patients (81%) had GBM and 8 patients (19%) had AA. Sixteen patients (38%) were ineligible for the neutron boost because of large tumors or poor performance status and instead received a photon boost with concomitant chemotherapy for a total dose of 60-65 Gy to the tumor. The overall median survival is 68 weeks at a median follow-up of 203 weeks (range 166-302 weeks for the 11 patients remaining alive); 7/8 patients with AA are alive, 2 of these with progressive disease. For AA the median survival is not reached at a median follow-up of 203 weeks (range 166-302 weeks for the 7 patients alive with AA). Time to tumor progression for the 1 dead patient with AA was 35 weeks and the other 2 patients failed at 171 weeks and 179 weeks following treatment. The median survival for the 34 patients with GBM was 62 weeks; 4/34 patients with GBM are alive at 285, 238, 216, and 206 weeks. Multivariate survival analysis in the 34 patients with GBM revealed age and Karnofsky performance status as important prognostic factors. Extent of surgery and neutrons did not affect survival. Concomitant chemoradiotherapy was well tolerated by all patients. The only toxicities observed were mucositis < or = grade II in 3 patients (7%) and mild myelosuppression in 1 patient (2.4%). Adjuvant PCV was well tolerated. Continuous concomitant chemoradiotherapy was well tolerated by all patients with acceptable side effects. The survival rate for the patients with GBM suggests no significant impact on the prognosis for these patients. Patients with AA did well; however, the patient numbers are small.

Reconstitution of the biosynthetic pathway of selenocysteine tRNAs in Xenopus oocytes.

Selenocysteine is cotranslationally introduced into a growing polypeptide in response to certain UGA codons in selenoprotein mRNAs. The biosynthesis of this amino acid initiates by aminoacylation of specific tRNAs (designated tRNA([Ser]Sec)) with serine and subsequent conversion of the serine moiety to selenocysteine. The resulting selenocysteyl-tRNA then donates selenocysteine to protein. In most higher vertebrate cells and tissues examined, multiple selenocysteine isoacceptors have been described. Two of these have been determined to differ by only a single modified residue in the wobble position of the anticodon. In addition, the steady-state levels and relative distributions of these isoacceptors have been shown to be influenced by the presence of selenium. In order to gain a better understanding of the relationship between these tRNAs and how they are regulated, both the Xenopus selenocysteine tRNA gene and an in vitro synthesized RNA have each been injected into Xenopus oocytes and their maturation analyzed. In this system, selenium enhanced RNA stability and altered the distribution of isoacceptors that differ by a single ribose methylation. Interestingly, the biosynthesis of one of these modified nucleosides (5-methylcarboxymethyl-2'-O-methyluridine), which has been identified only in the wobble position of selenocysteine tRNA, also occurs in oocytes. Examination of the modified residues in both the naturally occurring Xenopus selenocysteine tRNA and the products generated from exogenous templates in oocytes demonstrated the faithful reconstruction of the biosynthetic pathway for these tRNAs.

Acute toxicity during external-beam radiotherapy for localized prostate cancer: comparison of different techniques.

PURPOSE: The chronic and acute toxicities associated with conventional radiotherapy of localized prostate cancer are well documented. However, the degree and incidence of toxicities with conformal techniques are not known. Studying side effects associated with modern radiotherapeutic techniques is more important now since there has been a general trend to use computerized tomography-based techniques in recent years; beam's eye view-based conformal techniques are also becoming more commonplace. It is possible that the local disease control can be improved with the delivery of higher doses than currently used. Conformation of the treatment volume to the target volume may facilitate such dose-escalation. However, prior to such dose-escalation, it is important to know the toxicities associated with such techniques with conventional doses. METHODS AND MATERIALS: We have compared week-by-week acute toxicities associated with conventional (Group A, 16 patients), computerized tomography-based, manual (Group B, 57 patients) and beam's eye view-based (Group C, 43 patients) techniques during 7 weeks of radiotherapy. Group B and C patients were treated contemporaneously (1988-1990). RESULTS: Acute side effects gradually increased from week 1 through weeks 4-5 and generally declined or plateaued after that. The incidence of acute toxicities was significantly less with the beam's eye view/based technique than with the other two methods. For instance, the percentages of Grade 2 acute genitourinary toxicities for Groups A, B, and C were as follows: Week 1-0, 0, 0; Week 2-6, 0, 0; Week 3-6, 9, 2; Week 4-12, 14, 9; Week 5-35, 14, 9; Week 6-31, 16, 7; Week 7-33, 8, 8, respectively. The p values associated with differences in acute genitourinary toxicities for Weeks 1-7 using chi-square test were 0.072, 0.627, 0.389, 0.538, 0.123, 0.06, and 0.012; the p values for acute gastrointestinal toxicities were 0.512, 0.09, 0.031, 0.031, 0.003, < 0.0001, and 0.004, respectively. Pairwise comparison (Wilcoxon rank-sum test) showed statistically significant lower acute toxicity in Group C than Group B (e.g., p values, Weeks 1-7 for gastrointestinal toxicity: 0.633, 0.056, 0.010, 0.014, < 0.0001, < 0.0001, and < 0.0001, respectively) in the latter part of the treatment course. No correlation was found between the extent of toxicity and the patient age or the overall treatment time. Also, no correlation was found between the degree of toxicity and the radiation dose and fraction size, within the narrow ranges used (65-70 Gy and 180-200 cGy, respectively). A trend suggesting increased severity of toxicity with increase in the volume of treatment was seen. CONCLUSION: The findings in this retrospective study need to be confirmed by other prospective studies.

"Instant-mix" whole brain photon with neutron boost radiotherapy for malignant gliomas.

From July 1985 through March 1987, 44 consecutive patients with supratentorial, nonmetastatic anaplastic astrocytoma (AA) and glioblastoma multiforme (GBM) were treated with whole brain photon irradiation with concomitant neutron boost at the University of Chicago. All patients had biopsy proven disease and surgery ranged from biopsy to total gross excision. Whole brain photon radiation was given at 1.5 Gy per fraction, 5 days weekly for a total dose of 45 Gy in 6 weeks. Neutron boost radiation was prescribed to a target minimum dose that included the pre-surgical CT tumor volume plus 1 cm margin. Neutrons were administered 5-20 minutes prior to photon radiation twice weekly and a total dose of 5.2 Gyn gamma was administered over 6 weeks. Median follow-up was 36 months. The median survival was 40.3 months for anaplastic astrocytoma (10 patients) and 11 months for glioblastoma multiforme (34 patients) and 12 months for the overall group. Variables that predicted longer median survival included histology (AA vs. GBM), age (less than or equal to 39 years vs. older), and extent of surgery (total gross or partial excision vs. biopsy) whereas tumor size and Karnofsky performance status did not have a significant influence. The median survival of the anaplastic astrocytoma group was better than expected compared to the RTOG 80-07 study (a dose-finding study of similar design to this study) and historical data. Reasons for this are discussed.

Psychological gender, hand preferences, and sex differences in book-carrying styles.

Individuals with stronger sex-role identities may be expected to show greater conformity to sex-typed behaviors. Proceeding from this assumption, the sex-role status and sex of students using different styles of carrying books were compared. This study also examined whether over-all hand preference or age were related to carrying styles or sex-role status. Subjects completed a questionnaire comprised of the 24-item Personal Attributes Questionnaire of Spence and Helmreich, a 6-item scale of hand preference and a self-rating of sex-role identity. Afterwards, each subject's carrying style was covertly observed and recorded. Most subjects carried their materials in a sex-typical way or in book bags (for which no sex-typed carrying styles were discovered). As in previous studies, men in this study scored higher than women on masculinity and androgyny and lower on femininity. Hand preference was not related to sex-role status. Carrying style was not significantly correlated with any of the predictor variables for men, perhaps because almost no variance in carrying style was observed among them. Women who used masculine carrying styles tended to be older, have greater instrumentality, and a more masculine identity.