Abstract The aim of the present transversal study was to evaluate the clinical and biochemical salivary parameters of children with and without erosive tooth wear (ETW). The study population was children aged 4 to 9 years. A trained and calibrated examiner (kappa value for intraexaminer reliability = 0.89) classified the children into ETW (n = 24) and control groups (n = 24), and applied the O’Brien index. The salivary flow rate was initially evaluated by stimulated sialometry (paraffin chewing). Afterwards, the collected saliva was submitted to biochemical analyses of pH, uric acid, total buffering capacity, ferric-reducing antioxidant power, reduced glutathione, calcium, and phosphorus. Among the ETW children, 20 (83%) had dental lesions restricted to enamel, and 4 (17%) presented lesions affecting both enamel and dentin. A statistically significant difference between the groups was obtained only for the pH values (t-test; p = 0.004), with averages of 7.31 and 7.56 for the control and the ETW groups, respectively. Considering the parameters evaluated in general, it is suggested that the salivary profile of children with ETW does not differ considerably from that of children without ETW. However, the pH mean value seems to be slightly higher in ETW children, but is still within the normal physiological range.

The purpose of the present study was to evaluate the erosive potential of different types (concentrated and powdered) and commercial brands of industrialised grape juices. The pH of all five fruit drinks was measured at two time points: immediately after preparation and 24 hours later. Sixty specimens of bovine enamel were randomly allocated and immersed in different types of grape juice (n = 10) for 10 minutes four times a day for fifteen days. The enamel alteration was analysed using surface Knoop microhardness (KHN) and surface roughness (Ra) tests at baseline and on the 5th, 10th and 15th days of the experiment. Two way ANOVA, Tukey's post hoc and Pearson's correlation tests were used for statistical analysis (α = 5%). The grape juices presented pH values ranging from 2.9 to 3.5. All of the tested juices promoted significant enamel mineral loss (p < 0.05) on the first evaluation (5th day of immersion) and produced a significant increase in the mean roughness from the 10th day on when compared to the control group (p < 0.05). By the 15th day, all of the beverages had produced surface roughnesses that were significantly higher than that of the control group. The results suggest that all grape juices, regardless of their commercial presentation, present erosive potential.

OBJETIVO: A proposta do trabalho foi verificar a relação entre defeitos do esmalte e atraso da erupção dentária com prematuridade. MÉTODOS: A amostra consistiu de 100 crianças prematuras, entre seis meses a seis anos de idade em acompanhamento no Instituto da Criança da Faculdade de Medicina da USP. Foi feita uma anamnese da cavidade bucal por apenas um observador, avaliando o tempo da erupção dentária e a ocorrência de defeitos no esmalte. Realizou-se também uma avaliação médica, com dados referentes a possíveis problemas durante o período pré-natal, neonatal e pós-natal. A avaliação estatística utilizou análise descritiva, freqüência média e intervalo de confiança de 95%. RESULTADOS: Defeitos apareceram em 35% das crianças prematuras; 51,43% das que tinham defeitos haviam nascido com peso baixo (< 2500g) comparados aos 14,29% que haviam nascido com peso normal (>2500g) . Não houve relação entre ocorrência de defeitos com baixo Boletim de Apgar em 1 minuto, 2 minutos e 5 minutos (p=0,628; p=0,308; p=0,193). Os defeitos mais comuns foram as opacidades brancas, tanto na dentição decídua (19%) quanto na permanente (100%). Os terços incisais e cervicais das superfícies vestibulares foram os mais afetados com valores de 88,04% na dentição decídua e 100% na permanente. Cerca de 42% das crianças tiveram dentes irrompidos entre 6 e 10 meses. CONCLUSÃO: Crianças prematuras podem apresentar defeitos do esmalte causados por diferentes fatores durante a gravidez com uma possível associação entre baixo peso e defeito. Os dentes irromperam em tempo normal, no entanto, o número total de dentes até os 36 meses foi menor do que os encontrados em crianças nascidas a termo.

BACKGROUD: The purpose of this study was to analyze the relation between enamel defects and delay of dental eruption with prematurity. METHODS: the sample consisted of 100 premature children ranging from six months to six years of age, observed in the Children Institute of the Medical School of the USP. An anamnesis of the oral cavity was carried out by just one observer who analyzed the chronology of teeth eruption as well as the occurrence of enamel defects. A medical evaluation was also conducted in order to detect potential problems during the prenatal, neonatal and postnatal periods. The statistical assessment included descriptive analysis, average frequency and a confidence interval of 95%. RESULTS: Defects appeared in 35% of the premature children; 51.43% of those affected had been born with a low weight (< 2500g), compared to 14.29% born with normal weight (> 2500g). No relationship was found between the occurrence of defects with a low Apgar score during the first minute, second minute and five minutes (p=0.628; p=0.308;p=0.,193). The most common defects were white opacities, in the deciduous (19.0%) as well as in the permanent dentition (100%). The incisor and cervical halves of the vestibular faces were the most affected reaching values of 88.04% for the deciduous dentition and of 100% for the permanent one. In about 42% of children eruption of teeth took place between 6 to 10 months of age. CONCLUSIONS: Premature children may have enamel defects caused by different factors that appear during pregnancy with a possible association between low weight and enamel defects. Furthermore, premature children had teeth eruption in a normal period, nevertheless, until 36 months of age with less teeth total than children born at normal term.