Black Stain (BS) is the accumulation of iron in tissues and secretions, which along with chromogenic bacteria, are the primary cause of this pathology. In fact, among the metabolic products synthesised by bacteria in the oral cavity, hydrogen sulphide is of considerable interest. in pathological conditions (iron metabolism disorders), hydrogen sulphide upon reacting with iron available in saliva, forms black precipitates consisting of ferric sulphide. These precipitates bind to the surface of teeth, tending to form a stria that usually follows the contour of the gingiva, with an unsightly and variable chromatic intensity.

In physiological situations, iron homeostasis is defined as the state of equilibrium between iron present in tissues and in secretions and that which is present in the circulation. In pathological conditions, defined as iron metabolism disorders, there is an accumulation of iron in tissues and secretions and a lack of it in the circulation.

It is important to remember that subjects affected by BS are protected from carious processes than healthy subjects, probably due to a significant predominance of chromogenic bacteria compared to cariogenic bacteria. It should also be noted that in young subjects, BS tends to regress with pubertal development and the transition to adult life.

Black staining on teeth is extremely unesthetic and cleaning requires removal of iron precipitates causing the black stain. All the techniques for removing the precipitates, are not enough to fix and permanently eradicate their appearance, as these precipitates last only for short periods and recur very frequently.

In this Article

Introduction to Lactoferrin – our magical product for Black Stain

Lactoferrin (Lf) is a monomeric glycoprotein with a molecular weight of about 80 KDa, indicated as a red protein due to its characteristic colour caused by its completely saturated iron shape. In fact, this glycoprotein has the ability to chelate two ferric ions (Fe3+) per molecule. Lf belongs to the transferrin family (Tfs) proteins which chelate two ferric ions per molecule, including ovotransferrin (oTf) and serum Tf (sTf).

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Lf was identified, initially, in human and bovine milk, and subsequently in the milk of other mammals (goats, pigs, horses and mice). Today we know that Lf is present in small quantities even in human secretions such as saliva, tears, bile, seminal fluid and pancreatic juice.

Functions of Lactoferrin

Absorption of Fe
Modulation of hematopoiesis
Antimicrobial activity
Immuno-stimulatory action
Activity inhibiting the release of histamine from mast cells
Modulation of Fe homeostasis;
Anti-inflammatory activity
Reduces the development of tumor cells in patients with leukemia and inhibits the formation of metastases in breast cancer

Mechanism of Action of Lactoferrin

Lf is also able to perform a bactericidal action through interaction with microbial surfaces. Through this interaction, Lf is able to damage the membrane of gram negative bacteria by binding to lipopolysaccharide (LPS), purines and other surface molecules. The binding and successive release of LPS causes an increase in membrane permeability, thus making the bacterium more sensitive to the action of antibiotics or inducing lysis. However, it has also been demonstrated that the presence of Ca2+ and Mg2+ ions stabilises bacterial membranes, inhibiting the release of LPS and the consequent microbial lysis by Lf.

Furthermore, the Fe3+ chelating activity of the Lf is temperature and pH dependent. Finally, the digestion of bLf and hLf with pepsin leads to the formation of a series of cationic peptides, called “lactoferricins”, with high bactericidal activity. These peptides, which are not able to chelate the ferric ion, have however the ability to interact with LPS by lysing bacteria.

Administration of Lactoferrin

The protocol includes oral administration of Lf (for example, Forhans Gengi-For® orosoluble tablets containing 50mg Lf + 50mg D-Biotin) twice a day after proper and accurate oral hygiene. This treatment was performed after professional and home hygiene practices.

Lf perform two functions simultaneously: an antibacterial activity against the anaerobic microorganisms (responsible for BS) and an iron sequestration which makes it no longer available for the formation of ferric sulfide.

Procedures

Check the familiarity of the subject for Black Stain

Identify any subjects of the same family with Black Stain
Enrollment of the subject and affected family members
Select the degree of Black Stain according to the Gasparetto classification
Photograph the teeth affected by Black Stain before.

Gasparetto classification –

Score 1 corresponded to the presence of pigmented dots or thin lines with incomplete coalescence parallel to gingival margin.
Score 2 corresponded to continuous pigmented lines, which were easily observed and limited to half of the cervical third of the tooth surface.
Score 3 corresponded to the presence of pigmented stains extending beyond half of the cervical third of the tooth surface.

Starting any type of treatment

Teach proper home dental hygiene techniques
Perform professional dental cleaning
Carry out AirFlow or micro abrasion treatment with accurate polishing
Prescribe 2 orosoluble tablets per day of Forhans Gengi-For® – to be taken after oral hygiene – to be dissolved completely and slowly in the mouth, spreading the solute on the surface of the teeth and in the inter proximal spaces with the tongue
Perform first check-up at 2 months, documenting the possible effect of the administration of Forhans Gengi-For® by taking photos of the treated teeth and checking the patient’s compliance.

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Hygiene rules to be respected

Use a new traditional or electric / sonic toothbrush
Let the brush dry after use and do not insert it in the brush cover
Get rid of toothbrush holders
Prescribe a toothpaste Forhans Scudo Naturale containing lactoferrin
Check-up by dental hygienist after 2 and 6 months:
2 months: photographic documentation of the effectiveness of the treatment

Conclusions

From what has been described and from the reported cases, it appears evident that iron is the main protagonist, as well as the cause of the formation of BS. There is strong evidence that foods fortified with iron or iron containing vitamin complexes, enhancing the availability of this element, increase the possibility of the formation of ferric sulphide which manifests itself as a deposit of black pigments on the surface of the teeth.

On the other hand, since every disorder of iron homeostasis leads to its overload in secretions and a lack of it in the circulation, treatment with bLf is particularly indicated during pregnancy. In fact, although further clinical studies are required, these results indicate that Forhans Gengi-For® can be an effective and innovative therapy able to counteract this harmless but unsightly pathology through the sequestration of the excess of ferric ions in the saliva and the relative control of bacteria depending on the presence of iron for their growth.