Oral Health and Preventive Dentistry, 01/2004

To assess dental erosion caused by 0.1% and 1.0% citric acid in vitro and to estimate the protective influence of experimentally formed salivary pellicle. Bovine enamel slabs (n = 80) were polished and embedded in epoxy resin. For the formation of pellicle layer 40 specimens were immersed for 24 h in pooled human saliva. Erosion was caused by immersion in citric acid solution for 1, 5, 10 and 30 min. Erosive alterations on the pellicle-covered and non-covered enamel specimens were scored as a change (Δ) of surface roughness parameters Ra, Rt and RzDIN using contact profilometer and observed in scanning electron microscope. Profilometric analysis of eroded enamel specimens emphasized the aggressiveness of even low concentrated citric acid with a short period of challenge. The change of roughness parameters after 1-min immersion in 0.1% citric acid were 16.4, 182.6 and 132.2 nm for ΔRa, ΔRt and ΔRzDIN, respectively, and 54.8, 516.6 and 258.2 nm after 1-min immersion in 1.0% citric acid. Changes of the surface roughness were dependent on the exposure time and concentration of acidic solution. Pellicle layer significantly reduced the extent of erosive destruction, which was additionally documented on SEM-micrographs. Residual pellicle-like structures were detected after 5 min of immersion in 0.1% citric acid. However, there were no significant differences in pellicle-covered and non-covered enamel slabs measured profilometrically for 1.0% citric acid with 10 min and 30 min exposure time. The findings confirm the property of pellicle layer to resist against erosive influence of organic acids, which is, however, limited by duration of acidic treatment and concentration of erosive agent. Parole chiave: enamel erosion, salivary pellicle, surface roughness, scanning electron microscopy

Milk can be used as vehicle for fluoride administration. The aim of this study was to investigate the lactic acid formation in dental plaque after daily intake of fluoridated milk. The study group consisted of 15 healthy schoolchildren, 6 - 15 years of age, in a double-blind crossover study design. After a one-week fluoride depletion period, 250 ml of fluoridated (5 ppm; total amount 1.25 mg F) standard milk or non-fluoridated control milk was consumed once daily together with an ordinary meal during 3 days of plaque accumulation with no oral hygiene. On the fourth day, plaque samples were collected immediately before a final milk intake and then after 30, 60 and 180 minutes. After a washout period of two weeks, the whole procedure was repeated with the corresponding fluoridated or non-fluoridated milk regimen. All samples were suspended and the sucrose-challenged lactic acid formation rate was determined enzymatically. The results showed a statistically significant (p 0.05) increase of the lactic acid levels 30 min after the intake of the standard (control) milk while no such elevation was evident after the fluoride-containing milk. No differences were found after 60 and 180 min compared with baseline for any of the milks. The findings suggest that fluoride added to milk may counteract the lactic acid formation that follows a non-fluoridated milk intake. Parole chiave: children, dental plaque, fluoride, lactic acid, milk

To assess the microleakage of a pit and fissure sealant after preparing enamel with sono-abrasion, used alone or associated with acid etching. This technique was compared with classical enamel preparations i.e. acid etching and diamond bur associated with etching. Ninety 3rd molars were used. In the mesial halves, the fissures were prepared with sono-abrasion and acid etching for 15 seconds. Then, the samples were randomly assigned to three groups of 30. They were either treated with acid etching alone (group 1), widened mechanically with a bur and etched for 15 seconds (group 2) or prepared with sono-abrasion alone (group 3). Then, the resin-based sealant was applied according to the manufacturer's recommendations. The teeth were thermocycled and placed in a 1% solution of methylene blue. The teeth showing microleakage and the means of infiltration were assessed with an image analysis system. The poorest results were obtained with sono-abrasion alone which showed a greater number of specimens with microleakage (73.3%) (p 0.001). They also showed the highest mean of microleakage (0.85 ± 0.79 mm vs 0.1 ± 0.26 for acid; 0.35 ± 0.85 for bur associated with etching p 0.0001); and 0.19 ± 0.45 for sono-abrasion associated with etching. No significant difference was noted between the three types of enamel preparation using etching. Sono-abrasion can be used for preparing dental enamel prior to sealing the tooth but it does not eliminate the need for etching. Parole chiave: sealant, sono-abrasion, microleakage, SEM

To assess the prevalence of dental caries among school children in Egor local government area (district) and establish baseline data. Cross-sectional survey of urban and rural, private and public school children in Egor district, Edo State, Nigeria. A total of 358 randomly selected school children aged 12 to 15 years from urban and rural, private and public schools in Egor District were examined for dental caries according to the World Health Organization (WHO) criteria. A questionnaire was administered to elicit information from the participants on tooth cleaning, dietary habits and dental experience. An oral health campaign was conducted in the selected schools as an incentive. Data were analyzed using SPSS 7.5. Sixty-seven percent (n = 238) of the school children were caries-free. Mean DMFT score was 0.65 (sd = 1.14). Decayed teeth accounted for the largest component (98.6%). No fillings were recorded. Prevalence (mean DMFT) was higher in females (0.70) than males (0.59); urban (0.72) more than rural (0.53); private schools (0.75) more than public schools (0.55). DMFT scores at age 12, 13, 14 and 15 were 0.51, 0.63, 0.78 and 0.66 respectively; 81.4% of the school children had never visited a dental clinic, 95.8% claimed to use a toothbrush and 87.5% regularly consumed snacks. The prevalence of caries in Egor District is very low. Untreated caries indicates that preventive and restorative treatment needs are high. Dental and dietary habits are likely to increase this prevalence; hence the need for continuous monitoring, preventive and restorative programmes. Parole chiave: dental caries, schoolchildren, dietary habits, tooth cleaning, Nigeria

To assess the relationship of dental extrinsic stains (DES) with levels of trace elements in drinking water sources. A cross-sectional study among the population of Madesha VDC. A sample of 551 residents aged between 4 years and above was examined. A questionnaire was prepared to assess the dietary habits, oral hygiene practices, age, period of residency (POR), followed by clinical examination regarding the presence or absence of DES. Water samples were collected and sent for analysis by AAS method for trace elements. The prevalence of DES was 39%. Twenty-eight water samples had Fe levels that exceeded permissible levels and all samples were negative for other trace elements. Stains were associated with POR and levels of Fe in water (P value 0.001). There was a positive correlation by ward of Fe levels and stain distribution. The results revealed an association between DES with age, POR, and Fe levels in water. The positive correlation between stain distribution by ward and levels of Fe in water indicated the causative role of Fe in stains. Parole chiave: dental extrinsic stains, metallic stains, trace elements, Fe

Previous studies have reported higher dental fluorosis prevalence in high-altitude communities than in low-altitude communities. This investigation determined and compared dental fluorosis prevalence in populations of children living at high and low altitudes in Mexico. Fluorosis prevalence was determined in 7 to 10-year-old children: 67 in Mexico City (2,240 m) and 71 in Veracruz (sea level). Previous fluoride exposure of those children was surveyed by retrospective, questionnaire data. The fluoride content of water and salt from those communities was also documented. Fluorosis prevalence in Mexico City (53.0%) was significantly higher than in Veracruz (24.3%) (p 0.0001). While there were statistical differences in one of the fluorosis risk factors between the two communities, the observed difference in fluorosis prevalence was still significant when data were analyzed after adjusting for the reported differences in that factor. Our results led to the conclusion that the difference in fluorosis prevalence in Mexico City and Veracruz could not be explained by differences in fluoride content of the salt or water samples, self-reported exposure to fluorosis risk factors or estimated fluoride intake. Parole chiave: fluoride, fluorosis, altitude

To assess the evidence on the effectiveness of commercially available anticalculus dentifrices. Systematic search for published and unpublished epidemiological data in 7 electronic databases, 5 journals, and the bibliographies of retrieved papers and by making contact with subject experts in this field. Thirty-two reports were identified containing comparisons of one or more active agents with a placebo dentifrice and calculus measured using the Volpe-Manhold Index (VMI). Random effect model for 3-month studies showed an effect size of -0.6 for all comparisons. The effect sizes varied from -0.3 for dentifrices with zinc chloride 0.5% to -1.1 for pyrophosphate 1.3% and copolymer 1.5% dentifrices. Meta-analysis of all the studies with 6-month follow-up gave an effect size of -1.1 (-1.5 to -0.8) and for 12-month follow-up the effect size was -13.6 (-21.4 to -5.8). Anticalculus dentifrices containing pyrophosphates, zinc compounds and/or co-polymers were effective in significantly reducing calculus scores (VMI). Parole chiave: calculus, anti-calculus, dentifrices, pyrophosphate, zinc citrate, co-polymer, toothpaste, systematic review

The aim of this retrospective study was to assess the safety of dental treatment in pediatric patients with acute lymphoblastic leukema (ALL), and Hodgkin lymphoma (HL) and non-Hodgkin lymphoma (NHL), and to report any complications related to dental treatment during a preventive dental program covering a 4-year period. In this study 74 preventive fissure sealants, 69 fillings and 81 extractions along with periodontal treatment that included prophylaxis and/or scaling were performed on 124 patients with a mean age of 7.00 ± 2.3. The patients were monitored for at least three weeks after the treatment for bleeding, pain, local and/or systemic infection, fever, delayed wound healing or any other complication. Two patients (one ALL and one HL) suffered delayed wound healing after extractions which resulted in the delay of chemotherapy. In three of the patients who were in remission-induction phase of ALL, oral mucositis occurred in the cheek mucosa adjacent to extraction sites and five patients had tooth staining due to the routine use of a chlorhexidine mouthrinse. The healing was uneventful in all other patients. The findings of this study suggest that with special precautions such as adequate hematological values, timing of the intervention and supportive medical care, dental treatment can be safely performed in pediatric patients with hematological malignancies. Parole chiave: leukemia, lymphoma, dental treatment, tooth extraction, periodontal therapy