In vitro evaluation of variances between real and declared concentration of hydrogen peroxide in various tooth-whitening products

OBJECTIVES

The aim of this in vitro study was to analyze the real hydrogen peroxide (HP) concentration in various commercially available tooth-whitening products containing HP and/or carbamide peroxide (CP).

MATERIALS AND METHODS

Sixteen commercially available tooth-whitening products containing various concentrations of CP or HP were investigated. The products were divided into four groups: dentist-supervised home bleaching products (Group 1, n = 5), in-office bleaching products (Group 2, n = 4), over-the-counter bleaching products (Group 3, n = 3) and whitening toothpastes and rinses (Group 4, n = 4). The peroxide concentration was determined using the oxy-reduction titration method. All the reagents used in the study were of analytic grade and freshly prepared before the experiment.

RESULTS

The HP concentration in various dentist-supervised home bleaching products and in-office bleaching products ranged from 3.02-37.08% (expected range = 3-38%). The HP concentration of over-the-counter whitening products ranged from 1.24-5.57% (expected range cannot be estimated as no concentration of active ingredient was provided). Among whitening toothpastes and rinses, Colgate Plax whitening rinse showed more than 1% HP concentration, whereas it was lower than 0.05% in other whitening toothpastes and oral rinses (expected range cannot be estimated as no active ingredient was mentioned).

CONCLUSIONS

HP concentration of most of the professional tooth-whitening products was different from the expected concentrations, although the deviations were small and most of the products were close to the expected concentration. No concentration of active ingredient was provided for over-the-counter whitening products and no active ingredient was mentioned for whitening toothpastes and rinses.

Effect of various tooth-whitening products on enamel microhardness

OBJECTIVES

The purpose of this in vitro study was to evaluate the effect of various tooth-whitening products containing carbamide peroxide (CP) or hydrogen peroxide (HP), on enamel microhardness.

METHODS

Enamel blocks were exposed to: Nite White ACP 10% CP (Group 2, n=10); Yotuel Patient 10% CP (Group 3, n=10); Opalescence PF 10% CP (Group 4, n=10); Opalescence PF 20% CP (Group 5, n=10); Opalescence Treswhite Supreme 10% HP (Group 6, n=10); Yotuel 10 Minutes 30% CP (Group 7, n=10); Opalescence Quick 45% CP (Group 8, n=10), Yotuel Special 35% HP (Group 9, n=10), Opalescence Boost 38% HP (Group 10, n=10) according to the instructions of the manufacturers. The control (Group 1, n=10) was enamel blocks kept in artificial saliva at 37 degrees C without any treatment. The microhardness values were obtained before exposure and after a 14-day treatment period. Specimens were kept in artificial saliva at 37 degrees C between treatments. Data were analysed using Kruskal-Wallis one-way ANOVA and Tukey-Kramer Multiple Comparison Test. Indent marks on the enamel blocks were also examined under the Scanning Electron Microscope.

RESULTS

All whitening products decreased enamel microhardness except group 10 but only Groups 2, 3, 4, 5 and 7 showed significant decrease in enamel microhardness as compared to the control group (p < 0.05). Groups 2, 3 and 7 differed significantly from all the other groups (p < 0.05). The highest damage was recorded for Group 2 (Nite White ACP 10% CP), which differed significantly from Groups 3 and 7. SEM images also showed damage to enamel.

CONCLUSIONS

All products tested in this study decreased enamel microhardness except Opalescence Boost 38% HP. The products containing carbamide peroxide were more damaging to enamel because of the longer application times. Nite White ACP 10% CP showed the highest reduction in enamel microhardness as compared to other products tested.

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).

Global trends in dental fluorosis from 1980 to 2000: a systematic review

AIM

To determine trends in fluorosis prevalence at water fluoride levels <0.3, >0.3 to <0.7, and >0.7 to 1.4 ppm from 1980 to 2000.

METHODS

A systematic review of 55 published articles identified in a Medline search for peer-reviewed articles on fluorosis published from 1 January 1980 to 31 December 2000. The prevalence recorded with any fluorosis index was pooled and the trends over time were determined in the three water concentration categories.

RESULTS

The fluorosis prevalence for the three fluoride categories were 16.7, 27.4 and 32.2 percent, respectively. A 16-fold and a 2-fold increase in fluorosis prevalence compared with reported rates in the 1940s was seen in non-fluoridated (= 0.3 ppm F) and fluoridated (>0.7 to = 1.4 ppm F) areas, respectively. There has been an increase in fluorosis prevalence over time in the three fluoride water concentration categories but linear regression analysis showed that none are significantly different from zero.

CONCLUSION

This systematic review concurs with recent reports of an increase in fluorosis prevalence in fluoridated and non-fluoridated communities.

Gender and race distribution of dental graduates (1985-2004) and first year dental students (2000-2005) in South Africa

This paper, written at the close of a decade of democracy in South Africa, sets out to analyse the demographic profile of dental graduates from 1985-2004 at the five Faculties/Schools of Dentistry in South Africa. A comparison of the profiles for the pre-democracy (1985-1994) and post-apartheid (1995-2004) periods has been made. The demographic profile of first year dental students from 2000-2005 is also presented. From 1985-1994, most dental graduates were male (79%), but this changed substantially from 1995-2004, with females comprising 46% of those graduating. In the pre-democracy period, more than three-quarters of all graduates were White (78%), decreasing to 46% in the post-apartheid period under review. Black graduates increased from 6% to 24% across the two study periods. Amongst the first year dental student intake from 2000-2005, females comprised 57%. There was an almost equal distribution across the White, Black and Asian groups. Dental faculties/schools have made important strides in transforming the demographic profile of their students. The percentage of Black graduates, however, needs to be significantly increased if it is to reflect the national population. Faculties/schools must further ensure that able students from working class background are identified and considered for acceptance into the undergraduate dental programme, and should then be offered the necessary academic and mentoring support to enable success.

International comparisons of health inequalities in childhood dental caries

OBJECTIVE

To undertake formative studies investigating how the experience of dental caries in young children living in diverse settings relates to familial and cultural perceptions and beliefs, oral health-related behaviour and oral microflora.

PARTICIPANTS

The scientific consortium came from 27 sites in 17 countries, each site followed a common protocol. Each aimed to recruit 100 families with children aged 3 or 4 years, half from deprived backgrounds, and within deprived and non-deprived groups, half to be "caries-free" and half to have at least 3 decayed teeth.

OUTCOME MEASURES

Parents completed a questionnaire, developed using psychological models, on their beliefs, attitudes and behaviours related to their child's oral health. 10% of children had plaque sampled.

RESULTS

2,822 children and families were recruited. In multivariate analyses, reported toothbrushing behaviours that doubled the odds of being caries-free were a combination of brushing before age 1, brushing twice a day and adult involvement in brushing. Analyses combining beliefs, attitudes and behaviours found that parents' perceived ability to implement regular toothbrushing into their child's daily routine was the most important predictor of whether children had caries and this factor persisted in children from disadvantaged communities. 90% of children with lactobacillus had caries.

CONCLUSIONS

Parental beliefs and attitudes play a key role in moderating oral health related behaviour in young children and in determining whether they develop caries. Further research is indicated to determine whether supporting the development of parenting skills would reduce dental caries in children from disadvantaged communities independent of ethnic origin.

Familial and cultural perceptions and beliefs of oral hygiene and dietary practices among ethnically and socio-economicall diverse groups

OBJECTIVE; The aim of this international study was to develop a valid and reliable psychometric measure to examine the extent to which parents' attitudes about engaging in twice-daily tooth brushing and controlling sugar snacking predict these respective behaviours in their children. A supplementary objective was to assess whether ethnic group, culture, level of deprivation or children's caries experience impact upon the relationships between oral health related behaviours, attitudes to these respective behaviours and to dental caries.

CLINICAL SETTING

Nurseries, health centres and dental clinics in 17 countries.

PARTICIPANTS

2822 children aged 3 to 4 years and their parents.

MAIN OUTCOME MEASURES

Dental examination of children and questionnaire to parents.

RESULTS

Factor analysis identified 8 coherent attitudes towards toothbrushing, sugar snacking and childhood caries. Attitudes were significantly different in families from deprived and non-deprived backgrounds and in families of children with and without caries. Parents perception of their ability to control their children's toothbrushing and sugar snacking habits were the most significant predictor of whether or not favourable habits were reported. Some differences were found by site and ethnic group.

CONCLUSIONS

This study supports the hypothesis that parental attitudes significantly impact on the establishment of habits favourable to oral health. An appreciation of the impact of cultural and ethnic diversity is important in understanding how parental attitudes to oral health vary. Further research should examine in a prospective intervention whether enhancing parenting skills is an effective route to preventing childhood caries.

Fluoridation in South Africa

The issues on fluoridation, fluorosis and fluorides in South Africa have been reported for the last 50 years. Efforts to implement water fluoridation between 1960 and 1980 failed partly due to lack of government action and a strong anti-fluoride lobby. The political change in South Africa since 1994 has given new support from the Ministry of Health for enabling legislation to implement water fluoridation in metropolitan areas where the technical support and some 55 per cent of the population reside. Fluoridation also addresses the equitable distribution of resources and access to a known benefit.

Seroprevalence of hepatitis B surface antibody in South African dental personnel

Because there are no data available on the seroprevalence of hepatitis B in dental personnel in South Africa, a study was performed to assess the antibody status to hepatitis B surface antigen among 129 dental (preclinical) students and 62 dental hygienists at the Western Cape Dental School of South Africa. A total of 11 dental students and nine hygienists were positive to hepatitis B surface antibody, indicating a seroprevalence of 8.5% and 14.5%, respectively. These results, reported for the first time in dental personnel in South Africa, imply that dental students and hygienists in this part of the world are exposed to a significant risk of contracting hepatitis B.

Prevalence of dental caries in preschool and primary school children in Mamre

In order to plan and implement a comprehensive dental preventive health programme for the children of Mamre, the prevalence of dental disease was determined for the children attending the preschool and the primary school in the village. The prevalence of dental caries is reported in this article. A high prevalence of caries in the primary dentition was found, 26.4% of all primary teeth present in the under-5.5-year age group, 41.0% of those in the 6-year age group, and 41.4% of those in the 9-year age group being decayed. The prevalence of dental caries in the permanent dentition was low but increased with age: 3.8% of all permanent teeth present in the 6-year age group, 3.7% of those in the 9-year age group, 6.3% of those in the 12-year age group and 7.2% of those in the 14-year age group being decayed.