INQUIRY Caries Research Casein-phosphopeptide amorphous calcium phosphate plus fluoride Background.—Randomized controlled clinical trials have verified that fluoride-containing dentifrices and mouthrinses diminish caries significantly. The ability to incorporate fluoride ions into plaque and enamel has been key in this process. The demineralization of tooth enamel by bacterial organic acids present in plaque produces calcium and phosphate ions. Adding fluoride ions to the plaque promotes the immediate formation of fluorapatite, which promotes remineralization of the enamel. Sufficient calcium and phosphate ions must be present, specifically, 10 calcium ions and 6 phosphate ions for every 2 fluoride ions are needed to produce one unit cell of fluorapatite. Patients with xerostomia may not have sufficient quantities available. Casein-phosphopeptide stabilized amorphous calcium phosphate nanocomplexes (CPP-ACP) have anticariogenic properties and significantly increase the quantities of calcium and phosphate ions in supragingival plaque. The ability of CPP-ACP plus fluoride ions to increase the incorporation of fluoride into supragingival plaque and subsurface enamel, thereby leading to enamel remineralization with acid-resistant mineral, was investigated. Methods.—The 14 volunteers included seven men and seven women aged 21 to 45 years. All had at least 22 natural teeth and no current caries activity, periodontal disease, or oral disease. A randomized, double-blind three-way cross-over design was used to study mouthrinses and dentifrices. In the mouthrinse study, the three mouthrinses were 2% CPP-ACP, 450 ppm fluoride as sodium fluoride in deionized water, and a placebo. The subjects rinsed three times a day for 60 seconds using 15 ml of their assigned rinse for 4 days. On the fifth day they rinsed after breakfast, then samples of supragingival plaque were collected 2 to 3 hours later. No other oral hygiene practices were used. All of the subjects used each of the three mouthrinses, with a 4-week washout period between the treatments. In the dentifrice study, five dentifrices were studied: placebo, 1100 ppm fluoride as sodium fluoride, 2800 ppm fluoride, 2% CPP-ACP, and 2% CPP-ACP plus 1100 ppm fluoride. The subjects used the dentifrice as a water slurry for 60 seconds four times a day for 14 days. The fluoride ion concentrations in the plaque and enamel were measured in both studies.
Results.—Adding CPP-ACP to the 450 ppm fluoride rinse significantly increased the amount of fluoride ions in plaque (Table 1). The plaque fluoride concentration was more than twice that obtained with fluoride-only rinses. All of the dentifrice formulations replaced mineral in the subsurface lesions. The dose-related remineralization shown with the 2800-ppm fluoride formula was significantly greater than with the 1100-ppm fluoride formula, which was significantly greater than the placebo result. The remineralization produced with 2% CPP-ACP plus fluoride was similar to the remineralization with the 2800-ppm fluoride. The combination of 2% CPP-ACP and 1100-ppm fluoride yielded the best remineralization results. On microradiography, the lesions showed that fluoride ion alone promoted remineralization of the surface layer but CPP-ACP promoted remineralization throughout the lesion with or without fluoride. Higher levels of fluoride ion were incorporated into the lesions with 2% CPP-ACP plus 1100-ppm fluoride dentifrice than with the fluoride alone. Discussion.—The CPP-ACP increased the incorporation of fluoride into plaque and into subsurface enamel. It also substantially increased the remineralization of subsurface lesions of enamel compared to the results with fluoride alone. These findings further support the importance of having sufficient calcium and phosphate ions present to promote remineralization with topical fluoride use. The combination of CPP-ACP and fluoride appears to be a better choice for reducing caries risk than using fluoride alone.
Table 1.—Fluoride Levels in Supragingival Plaque after Treatment with Various Mouthrinses Mouthrinse
Placebo control Fluoride (450 ppm) 2% CPP-ACP plus 450 ppm F
Plaque Fluoride Level (nmol/mg dry wt)
Dry Weight of Plaque (mg)
7.4 4.7a,b 14.4 6.7a,b 33.0 17.6a,b
4.3 2.5a 3.9 1.9a 5.0 2.1a
(Courtesy of Reynolds EC, Cai F, Cochrane NJ, et al: Fluoride and casein phosphopeptide-amorphous calcium phosphate. J Dent Res 87:344-348, 2008.) a Mean SD (n = 14). b Significantly different from all values in same column (P < 0.001).
Clinical Significance.—Fluoride’s role in caries prevention is well documented. As dentistry’s focus shifts from repairing defects to healing them, fluoride’s part in remineralization is being further studied. Reported here is work with a compound that enhances remineralization and increases the fluoride content of the reparative material.
Reynolds EC, Cai F, Cochrane NJ, et al: Fluoride and casein phosphopeptide-amorphous calcium phosphate. J Dent Res 87:344-348, 2008 Reprints available from EC Reynolds, Cooperative Research Ctr for Oral Health Science, School of Dental Science, Bio21 Inst, The Univ of Melbourne, 720 Swanston St, Victoria 3000, Australia; e-mail: [email protected]
Cariology Passive smoking and caries Background.—Passive smoking (PS), also termed environmental tobacco smoke, is a major public health concern that affects children in particular. Compared to adults, children have smaller bronchial tubes, their immune systems are less developed, and they breathe faster, taking in more harmful chemicals per kilogram of body weight. The effects of PS exposure in children is to predispose them to cancer, cardiovascular disease, asthma, infections of the lower respiratory tract, neurological disorders, and reduced cognitive abilities. Few studies have examined any possible relationship between PS and oral health. Cotinine is a primary metabolite of nicotine and maintains more stable plasma concentrations than nicotine does. It can be measured in body fluids and provides a useful screening tool for measuring PS exposure. This salivary biomarker was used to determine the relationship between PS and caries in young children. Methods.—One hundred eighty children (mean age 5 years) participated, with 90 having PS exposure and 90 healthy age-matched controls. Questionnaires were used to obtain information on family income, smoking habits of household members, parental education levels, child’s tooth-brushing habits, and child’s sugar exposure in the daily diet. The children were placed into three categories based on the number of cigarettes smoked in the household (<10, 10 to 20, or >20 cigarettes daily). Caries prevalence was recorded, and the score of decayed, missing and filled primary teeth (dmft) was determined using World Health Organization (WHO) criteria. Measurements of the children’s stimulated salivary cotinine level, pH, flow rate, buffering capacity, and Streptococcus mutans and lactobacilli colonization were obtained. Results.—The number of caries-free subjects in the PS group was significantly less than in the control group (Table 1). PS children also had a mean dmft score two times higher
than the control children. A greater proportion of PS subjects had high counts of S mutans and lactobacilli than in control subjects. Compared to controls, PS children also had statistically significant declines in salivary pH, flow rate, and buffering capacities. The mean cotinine levels for the PS and control groups were 1.58 ng/ml and under the limit of detection, respectively. No significant difference in cotinine level between boys and girls was noted.
Table 1.—Passive Smoking (PS) in Relation to Caries and Salivary Biomarkers of PS Subjects in Comparison with Control Subjects PS subjects Control subjects (n = 90) (n = 90)
Caries prevalence 80 (89.9%)* 59 (65.6%) dmft score mean S.D. 10.58 2.12* 4.64 2.91 Streptococus mutans (CFU/ml) n (%) Low 11 (12.2%)* 28 (31.1%) Moderate 37 (41.1%) 41 (45.6%) High 42 (46.7%) 21 (23.3%) Lactobacilli (CFU/ml) n (%) Low 13 (14.4%)* 29 (32.2%) Moderate 38 (42.2%) 43 (47.8%) High 39 (43.3%)* 18 (20.0%) Salivary pH (mean S.D.) median 6.49 0.27 7.2 0.38* Salivary flow rate (mean S.D.) 0.71 0.1 1.01 0.05* Salivary buffering capacity n (%) Low 39 (43.3%)* 22 (24.4%) Moderate 38 (42.2%) 36 (40.0%) High 13 (14.4%)* 32 (35.6%) Abbreviations: S.D., Standard deviation; CFU, colony-forming units. * P < 0.05 was statistically significant. (Courtesy of Avsar A, Darka O¨, Topaloglu B, et al: Association of passive smoking with caries and related salivary biomarkers in young children. Arch Oral Biol 53:969–974, 2008.)