ORAL CARE Zenaida B. Soriano, MS Senior ASEAN Expert Cosmetics

2 The Mechanism of Caries Caries results from the acid dissolution of tooth enamel. Several factors influence this process and the relationships among these factors are shown in the diagram below: Diet Plaque Bacteria CarbohydratesEnzymes Acid Tooth Enamel Demineralisation CARIES

3 A typical “white spot” or incipient caries lesion on the surface of a tooth.

4 A longitudinal section through a white spot illuminated by polarized light. The white spot is characterized by an unbroken, intact enamel surface with an underlying area of demineralised enamel.

5 A scanning electron micrograph (500x) of a slice taken through a white spot formed artificially in the laboratory. This shows the highly porous nature of a white spot caused by the demineralization of the enamel crystals.

6 Routes to Caries Prevention HSP CI Increase Host Resistance _______________ Water fluoridation Internal fluoride (i.e., tablets) Fluoride dentifrices Fluoride mouthwashes Professional fluoride treatments Occlusal sealants Professional care Vaccine (future?) Plaque removal and control _______________ Oral hygience Toothbrushing Flossing Chemical agents Destroy/inhibit bacteria Disrupt plaque structure Dental prophylaxes Patient motivation Diet Control Reduce carbohydrate intake Substitute noncariogenic sweeteners Control patterns of food consumption HS = host susceptibility; P = plaque; CI = carbohydrate intake

7 Mechanism of Fluoride Action Fluoride action can be considered a dual- phase phenomenon, i.e., pre and post- eruption of the teeth  Tooth formation – fluoride incorporated in the enamel as fluorapatite.  Pre-eruption maturation – incorporation of fluoride on enamel surface leading to more perfect apatite and well-structured enamel.

8 Fluoride can interfere with the carious process at 3 levels: At the level of plaque bacteria At the surface of the tooth before and during initial acid attack and During and subsequent to acid attack with lesion formation

9 Fluoride and Oral Bacteria The inhibitory effect of fluoride on plaque microorganisms has been cited by many investigators. Fluoride uptake by plaque is shown in Table 2:

10 Demineralization Studies In-Vitro Extracted human teeth were exposed to 0.1M lactate solution, pH 4.3 and containing 0.004, 0.009, 0.024, 0.054, 0.504, or ppm fluoride. Demineralization was followed by scanning electron microscope and polarized light microscopy. Rapid (within 72 hours) demineralization occurred in the absence of fluoride, and cavitation was observed.

11 In-Vivo The above results support in-vivo data of Pearce and co-workers who demonstrated that: 1. The deposition of sufficient amounts of fluoridated apatite can markedly inhibit intraoral demineralization of oral enamel blocks. 2. That those amount of fluoride can promote the remineralization of previously demineralized enamel.

12 In-Vivo “Under the dynamic conditions present within the oral cavity, fluoride will reduce the rate of enamel demineralization… as well as increase the resistance of the surface enamel to subsequent acid attack through the incorporation of fluoride”

13 Conclusions Fluoride has multiple mechanisms of action: 1.In the plaque above the tooth surface 2.At the plaque and tooth enamel interface 3.Below the tooth surface The frequency of application of fluoride or presence of fluoride during acid challenge, is more important to the efficacy of fluoride than the concentration of fluoride.

DENTAL FLUOROSIS

15 Estimated Intake of Fluoride Relative to Drinking Water

16 The EPA assessed the prevalence of dental fluorosis in relation to fluoride intake using results of dental fluorosis studies conducted over 48 years ( ) No moderate or severe fluorosis was observed at levels of 0.6 mg/L or less Moderate fluorosis was observed intermittently at levels of 0.7 to 1.8 mg/L At levels around 1 mg/L up to 2.2 mg/L, moderate fluorosis was observed in 0.15% of the children examined.

17 Safely Tolerated Dose of Fluoride with Age

SUMMARY

19 Aspects that impact on the formulation and usage of products for self-applied fluoride prophylaxis: Fluoride incorporated into properly formulated products for self-application is safe and effective. The mechanism by which fluoride acts to prevent and even reverse carious lesions are now supported by sound experimental evidence.

20 Aspects that impact on the formulation and usage of products for self-applied fluoride prophylaxis (contd.): Fluorides can present hazards to health, but only when its use is abused. There is support for the concept that fluoride can exert its effects at lower levels in individual products possibly because of the multiple routes of administration now being employed and cumulative effects thereof.

21 Aspects that impact on the formulation and usage of products for self-applied fluoride prophylaxis (contd.): The dental profession fully recognizes the importance and safety of fluoride in combating dental caries.

22 PERIODONTAL DISEASE Gingivitis: Inflammation of the gingiva caused by accumulation of plaque and tartar below the gum line. Associated with presence of specific bacteria Bacterial toxins released Host immune response Host susceptibility varies Bone loss does not occur Periodontitis: Advanced stage of periodontal disease. Inflammation and destruction of the supporting tissues. Tissue destruction due to bacterial toxins and release of enzymes from host’s immune system Gumline recedes / roots exposed Bone and tooth loss can occur Treatment includes surgery

PRODUCT SAFETY

24 Evaluation of the following aspects of safety should be considered for all cosmetics subject to ingestion, whether drugs or not: Oral toxicity Mucous membrane irritation Primary skin irritation Potential for contact sensitization Photosensitization Percutaneous toxicity

25 Efficacy of Fluoride Dentifrices in Clinical Trials

26 Safety of Fluoride Dentifrices The question of the safety of fluoride in dentifrices has been addressed on several levels: 1.Inherent chronic and acute toxicity 2.Age of user 3.Potential to cause fluorosis 4.Risk vs benefit The dental community, regulatory agencies, and the majority of the public have concluded that fluoride dentifrices pose no safety hazard under defined condition of use.

MOUTHWASHES or ORAL RINSES

28 Clinical Investigations Conducted with Mouth Rinses Containing Fluorides *All rinses are essentially neutral, unless otherwise indicated.

29 Clinical Investigations Conducted with Mouth Rinses Containing Fluorides *All rinses are essentially neutral, unless otherwise indicated.

30 Clinical Investigations Conducted with Mouth Rinses Containing Fluorides *All rinses are essentially neutral, unless otherwise indicated.

31 Clinical Investigations Conducted with a Mouth Rinse Containing 0.01 Per Cent of a Macrolide Antibiotic (CC 10232)

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