Effect of four different opalescence tooth-whitening products on enamel microhardness.

OBJECTIVES: The purpose was to evaluate the effect of various Opalescence tooth-whitening products on enamel. METHODS AND MATERIALS: Enamel blocks were exposed to Opalescence PF 10% Carbamide Peroxide (n = 10), Opalescence PF 20% Carbamide Peroxide (n = 10), Opalescence Trèswhite Supreme 10% Hydrogen Peroxide (n = 10) and Opalescence Quick PF 45% Carbamide Peroxide (n = 10) according to the manufacturer's instructions. The control group was enamel blocks (n = 10) kept in artificial saliva. The values were obtained before exposure and after the 14-days treatment period. Enamel blocks were kept in saliva between treatments. Indent marks on enamel blocks were examined using the scanning electron microscope for treatment effects. RESULTS: All four different Opalescence products damaged enamel. The most damage was done when treated for a long period (112 hours). SEM images also showed damage to enamel by all 4 products. Opalescence with 10% and with 20% Carbamide Peroxide showed the highest damage, which also differed significantly (p < 0.05) from the saliva control group (p < 0.05; Tukey-Kramer Multiple comparison test). CONCLUSION: All 4 Opalescence products damaged enamel. Higher damage was done by the 10% carbamide peroxide and 20% carbamide peroxide products because of the much longer exposure period (112 hours in comparison to 7 hours).

Dental fluorosis and caries experience in relation to three different drinking water fluoride levels in South Africa.

OBJECTIVES: The purpose of this study was to determine the relationship between caries experience, degree of fluorosis and different concentrations of fluoride in the drinking water of children. SAMPLE AND METHODS: The study included 282 children aged 10-15 years, who lived continuously since birth in three different naturally fluoridated areas (Leeu Gamka, 3.0; Kuboe 0.48 and Sanddrif 0.19 p.p.m. F), with virtually no dental care or any fluoride therapy The teeth of the children were examined for caries using the DMFT index according to th WHO criteria and for fluorosis, using Dean's criteria according to the WHO guidelines. RESULTS: The prevalence of fluorosis (scores 2, 3, 4 and 5) among the school children was 47% in Sanddrif, 50% in Kuboes and 95% in Leeu Gamka. Almost half the children in the two low fluoride areas had no fluorosis (scores 0 and 1), whereas only 5% in Leeu Gamka had no fluorosis. Of the children in Sanddrif, 42.5% had very mild/mild (scores 2 and 3) fluorosis, 44.3% in Kuboes and 34.1% in Leeu Gamka. Except for one individual in Kuboes, severe fluorosis (score 5) was only observed in the high fluoride area in 30% of the children. According to the Bonferroni adaptation for multiple comparisons, the degree of fluorosis in Leeu Gamka differed significantly from both those of Sanddrif and Kuboes. The mean DMFT for the children in Sanddrif and Kuboe was similar (164 +/- 0.30 and 1.54 +/- 0.24, respectively) but the caries experience of Leeu Gamka (198 +/- 0.22) was significantly higher (P < 0.05) than that of both the other two areas. A strong positive correlation (P < 0.05) was found between the caries experience and the fluorosis scores of children in the high fluoride area (Leeu Gamka) but no correlation could be found in the other two areas. Significantly (P < 0.01) more children had decayed teeth in the high F area (Leeu Gamka) than in the other two areas. CONCLUSION: The results suggest a positive association between high F levels in the drinking water and dental caries. Furthermore, a low caries experience and no difference in DMFT and fluorosis between the two low fluoride areas were found.

Oligozoospermia: a seven-year survey of the incidence, chromosomal aberrations, treatment and pregnancy rate.

No sperm count should be regarded too low to consider extensive treatment in order to improve semen or to correct any possible abnormalities in femal partners. The infertile couple should be given devoted care and advice to improve their sexual relations and their psychological attitude towards the problem of infertility. A pregnancy rate of 51.9% where the husband's count was less than 10 million/ml, offers adequate support for this statement. In cases of mental trauma inflicted on patients by a verdict of inability to achieve parenthood--on people who have already suffered severe psychological shock and tension resulting from a period of infertility--discouragement lessens the already doubtful chances of achieving pregnancy. In no circumstance should oligozoospermic patients receive treatment for infertility unless a chromosomal analysis has been completed and found normal, since our rate of chromosomal anomalies (11.4%) in a group of oligozoospermic patients is considered to be too high.