Are you facing a difficult clinicial situation ? Please post the query on the forums.

  • Sharebar


No replies
Drsumitra's picture
Joined: 6 Oct 2011

Honey has been used as a medicine throughout the ages, and in more recent times has been "rediscovered" by the medical profession for treatment of burns, infected wounds and skin ulcers. The large volume of literature reporting its effectiveness indicates that honey has therapeutic features that indicate it has potential for the treatment of periodontal disease, mouth ulcers and other problems of oral health. Honey has a potent broad-spectrum antibacterial activity that rapidly clears infection from wounds when applied topically, which may make it suitable for "anti-infective" treatment of periodontal disease as well as for clearing infection in mouth ulcers and wounds from oral surgery. The action of honey in preventing wounds becoming infected also indicates that it may be of use in preventing the development of dry socket after tooth extraction. The soothing effect resulting from the very effective anti-inflammatory action of honey may also be beneficial in these applications. The anti-inflammatory activity of honey, combined with its significant content of antioxidants, may also be of benefit in preventing the erosion of periodontal tissues that occurs as collateral damage from the free radicals released in the inflammatory response to infection. The stimulatory action of honey on the growth of granulation tissue and epithelial cells would also be of benefit in hastening the repair of damaged tissues. The relief of inflammation and stimulation of repair processes may also be of benefit for stomatitis associated with cancer therapy. Technology has been developed to produce honey in the form of candy or gels that would be suitable for these various therapeutic applications. The risk of caries resulting from the use of honey is likely to be decreased by selecting honey with a high level of antibacterial activity. Honeys can vary as much as a hundred-fold in their antibacterial potency. Using ones in the middle of this range it has been shown that cariogenic species of bacteria will not grow at concentrations of honey lower than would be occurring in saliva, nor will they produce dextran, and their production of acid is markedly inhibited. Honey selected to have a high level of antibacterial activity is available commercially, but selection of honeys with high levels of antioxidant and anti-inflammatory activity is currently just at the research stage.Various therapeutic features of honey have been noted in the many published reports on clinical studies and animal experiments where honey has been used as a dressing for wounds, skin ulcers and burns. This literature has been reviewed (Molan 2001a), as has the literature providing explanations for how honey exerts its therapeutic effects (Molan 2001b). Almost all of the reports are of treatment of external wounds rather than lesions and infections of mucosal surfaces, but the features observed are relevant also to many aspects of dental practice. It has been observed that honey clears infection, removes malodour, reduces inflammation and pain, causes edema and exudation to subside, and increases the rate of healing by stimulation of angiogenesis, granulation and epithelialisation. Many of these features could be expected to be secondary to the clearance of infection, since infection causes an inflammatory response which in turn causes pain, edema, exudation and a slowing or cessation of the healing process. However, they have been observed in also in experimental wounds in animals where no infection was involved. Nevertheless, the rapid clearance of infection is the most notable feature of honey as a wound dressing, in many cases it clearing infection when no conventional therapy had worked. And, unlike other antiseptics, honey is not cytotoxic so it does not slow healing, nor does it have any adverse side-effects like antibiotics do.

The antibacterial activity of honey has been know for almost as long as bacteria have been known to be the cause of infection, and the large amount of published research over the years revealing the broad spectrum of action and the potency of this activity has been comprehensively reviewed (Molan 1992a). It has been found that honey is effective against aerobic, anaerobic, Gram-positive and Gram-negative bacteria, also a variety of fungi, but the likely clinical usefulness of this activity is in many cases not clear because of failure to take into account the wide variance in potency of the activity of honey. More recently studies have been carried out using standardised honeys selected to be close to the median level of activity found in a survey of a large number of samples of commercially produced honey. These have demonstrated the potency of the activity of honey against infective bacteria to be sufficient to be likely to be useful clinically. In one study with 20 isolates of Pseudomonas from infected wounds (Cooper and Molan 1999) the minimum inhibitory concentration of honey was found to range from 5.5% to 9.0%. In another with 58 clinical isolates of Staphylococcus aureus (Cooper, Molan, and Harding 1999) the minimum inhibitory concentration of honey was found to range from 2% to 4% (v/v). Antibiotic-resistant strains of bacteria (MRSA and VRE) have been found to be just as sensitive to honey as the antibiotic-sensitive strains of the same species (Cooper et al. 2000), and there have been clinical reports of wounds infected with MRSA being cleared of infection and healed by application of honey (Betts and Molan 2001; Dunford et al. 2000; Natarajan et al. 2001).

Recent research indicates that honey may in addition to its antibacterial activity clear infection also through stimulating the activity of leukocytes. Cell culture studies have shown that low concentrations of honey stimulate proliferation of lymphocytes and activate phagocytes (Abuharfeil, Al-Oran, and Abo-Shehada 1999), and stimulate monocytes to release cytokines which are activators of the immune response to infection (Tonks et al. 2001). As well as this, honey supplies glucose which is essential for the ‘respiratory burst’ in macrophages that is an essential part of their mechanism of destroying bacteria. Additionally, honey provides substrates for glycolysis, the major mechanism of energy production in macrophages.The therapeutic features of honey seen in its usage in wound care elsewhere on the body indicate that it has the potential to be useful for prevention or treatment of infection in wounds following tooth extraction or oral surgery, and for treating other oral infections. There has been one report published of honey being used in oral surgery, describing a small clinical trial of the placing of honey in the socket before closure of the wound after surgical removal of impacted third molars (Elbagoury and Fayed 1985). (This trial showed less pain, less incidence of postoperative complications and less swelling in the honey-treated group than in the untreated control group.) The effectiveness of honey in such an application is likely to be very limited by its being likely to dissolve fairly quickly in the saliva and thus not be present to have a therapeutic effect for very long. If it could be held in place for long enough it would be expected that honey would be fully effective in preventing infection developing in sockets following extraction, as it has been found to do so in wounds elsewhere on the body. By preventing streptococci from growing it would be expected to prevent the development of dry socket, a condition that is due to protease activity from the bacteria removing the protective fibrin clot formed on removal of the tooth. A novel wound dressing material consisting of gelled honey that has been developed (PCT patent application by the University of Waikato, December 2000) may be useful for this, and for the treatment of mouth ulcers, as it adheres to the oral mucosa and is slow to dissolve in saliva. Clinical trials of this are yet to be run, but anecdotal reports of its use indicate that it is likely to prove to be successful: additional to any antimicrobial effect, the honey gave a rapid soothing of pain as has been observed with wounds and burns elsewhere on the body. A similar rapid alleviation of pain was observed when the gelled honey was used in a case of erosion of the gum and jaw bone due to infection following surgery with bone grafting to repair damage to the jaw from traumatic injury, that had been non-responsive to any conventional treatment for more than six months. In this case the gelled honey was moulded into the infected area and held in place by wearing a mouth guard over it. The infection cleared and the wound healed up within a month after starting the application of the gelled honey.

Honey having an anti-inflammatory activity raises the possibility of it being useful as a therapeutic agent for periodontitis also. Its antibacterial activity would provide "anti-infective" therapy of periodontal disease, by removing the etiological factor, and the anti-inflammatory activity would block the direct cause of the erosion of the connective tissues and bone. Furthermore, its activating effects on leukocytes could be beneficial, as some periodontitis is due to immune cell hypofunction allowing pathogens to grow unchecked and cause direct tissue damage (Chapple 1996). Yet immune cell hyperfunction can cause collateral damage to tissues through the release of reactive oxygen species (free radicals), byproducts of inflammation (Chapple 1996). The initial inflammatory response is elicited by bacterial cell wall components, but reactive oxygen species released from the activated phagocytes feed back as signals to elicit further inflammatory response. The erosive damage caused by the persisting state of inflammation in periodontal disease can be stopped by removing the bacteria causing the continuous stimulation of an inflammatory response or by blocking excessive inflammatory response. It has also been proposed that antioxidants be used to protect the periodontal tissues from the damaging free radicals formed in the inflammatory response (Battino et al. 1999). Honey contains a substantial level of antioxidants (Frankel, Robinson, and Berenbaum 1998), and has an anti-inflammatory action that has been clearly demonstrated to be direct and not secondary to the clearance of infection (Molan 2001a). Another beneficial feature of using honey to treat periodontal disease would be its well established stimulation of the growth of granulation tissue and epithelial cells (Molan 2001a), which would aid in repair of the damage done by infecting bacteria and by the free radicals from the inflammatory response to them.

The anti-inflammatory action and stimulating effect on tissue repair of honey could possibly be of benefit for the relief of oral conditions resulting from radiotherapy and chemotherapy of cancer. Publications on the use of honey on thermal burns to the skin report that honey reduces inflammation, and anecdotal reports indicate that the anti-inflammatory activity of honey applied to the skin after radiotherapy minimises radiation burns to the skin. There has also been a published report on using honey to ease the pain of stomatitis during radiotherapy (Chiba et al. 1985). There are also anecdotal reports of honey being effective in relieving the gastritis associated with chemotherapy of cancer. Research on the mechanism of action of honey in protecting against damage to the gastric mucosa caused by other agents indicates that it is the anti-inflammatory activity of honey that is responsible (Molan 2001b).

But a practical difficulty if using honey therapeutically in the mouth is that of applying the honey to the lesion and keeping it in place. For therapy of periodontal disease one possibility is to use a soft form of the gelled honey wound dressing material discussed above, which could be smeared along the gingival margin periodically. Experience with use of honey in wound care indicates that the antibacterial and anti-inflammatory components of honey will diffuse well into tissues from topical application. Another possibility is to use honey in place of toothpaste. (A dentifrice abrasive could be included in the honey to ensure a good cosmetic result.) For less localised lesions the use of candy made with honey (discussed below) would be a way of keeping honey in contact with oral tissues for a protracted period.

Candy made with honey may also be useful for prevention of halitosis, as honey has been observed to give rapid removal of malodour from infected wounds (Molan 2001a). It would not be just the antibacterial action of honey involved, as bacteria would use the glucose in honey in preference to amino acids, and thus would produce lactic acid instead of bad-smelling amines and sulphur compounds (Nychas, Dillon, and Board 1988). Normally the consumption of candy would be of concern because of the increased risk of caries, but with the use of honey with a high level of antibacterial activity this risk may be reduced, as discussed below.

Is honey harmful to the teeth?

There has been much debate in the past about whether or not honey is harmful to the teeth, mostly as part of the debate about raw sugar versus refined sugar. Occasionally has come into this debate the recognition that honey has antibacterial activity, but where the effect of this has been investigated the results have been equivocal. However, what has not been taken into account is that honey varies very markedly in the potency of its antibacterial activity. Recent research with honey selected to have a good level of antibacterial activity has shown that there is potential for protection of dental health if such honey were used in place of refined sugar in the manufacture of candy.

With honey having a high content of fermentable sugars it could be expected that it would be cariogenic. Various researchers in the past have investigated this, using animal studies. However, only two papers showed awareness of honey having antibacterial properties (Decaix 1976; George, Sadek, and Roziek 1978), and none took into account the variance in potency of the antibacterial activity of honey, each study using a single unselected honey. In three of the studies honey was found to be equally as cariogenic as sucrose was (George, Sadek, and Roziek 1978; Nizel 1973; Shannon, Edmonds, and Madsen 1979). In another two, honey was found to be more cariogenic than sucrose was (König 1967; Wakeman et al. 1948). But another study found honey to be much less cariogenic than sucrose (Decaix 1976).

Honey has also been tested in comparison with sucrose in a model system where the sugars were added to saliva and incubated in the presence of calcium phosphate (Jenkins, Forster, and Speirs 1959). In this study three different, non-selected, honeys were used. Two of them caused more mineral to be dissolved than sucrose did, but the other one caused less to be dissolved than sucrose did.

Other research has been carried out to determine the effect of honey on the growth of cultures of oral bacteria, again using single unselected honeys. One study, on seven species of oral streptococci, found that the minimum inhibitory concentration of honey for Strep. oralis was 12%, for Strep. anginosus was 17%, and for Strep. gordonii, Strep. mutans, Strep. salivarius, Strep. sanguis and Strep. sobrinus was 25%, which was the same as the minimum inhibitory concentration of sucrose (Basson, du Toit, and Grobler 1994). Another study (Steinberg, Kaine, and Gedalia 1996) also found the minimum inhibitory concentration of honey for Strep. mutans was 25%, and for Strep. sobrinus was 35%, which also indicated that there was little if any antibacterial action in the honey beyond the osmotic effect of its sugar content. This study did however find that the salivary bacterial count was reduced by 40% one hour after holding 5 ml of honey in the mouth for 4 minutes, but this could have been due to a stimulation of flow of saliva washing away the bacteria. In a study where various honeys were used, the strength of inhibition of growth of Strep. mutans was found to be correlated with the amount of hydrogen peroxide produced in the honey (Dustmann 1987). The degree of inhibition of production of lactic acid by the bacteria was also found to depend on the amount of hydrogen peroxide produced in the honey. It was also observed that no dextran was produced by Strep. mutans growing on a medium containing honey whereas it was produced with sucrose in the medium.

More recently research has been carried out to find the minimum inhibitory concentration of honey for species of bacteria believed to cause caries, using honeys with standardised antibacterial activity to take into account the large variation in potency that can occur (Fjällman 2000). The honeys were selected to have a level of antibacterial activity near the median found in a survey of the activity level of hundreds of samples of commercially-produced honey. It was found that the minimum inhibitory concentrations of honey for Strep. mitis, Strep. sobrinus and Lactobacillus caseii were 7%, 7.5–8.5% and 8–12% respectively. The production of acid by these bacteria was also inhibited. Compared with that produced from sucrose, honey at a concentration of 10% gave 75–80% less acid production from the streptococci and 30% less from L.caseii. There was no dextran produced from 10% solutions of the honeys. When the honeys were added at a concentration of 10% to a medium containing 10% sucrose the production of dextran from sucrose was inhibited by 75–89%.

It can be concluded therefore that although honey may be cariogenic because of its high content of fermentable sugars, with selected honeys that have higher levels of antibacterial activity there is the potential for harm to the teeth to be reduced by inhibition of the cariogenic bacteria. But the degree to which this occurs in the mouth would have to be determined by feeding experiments.

Another concern with keeping honey in the mouth for prolonged periods if it were consumed as candy is that its acidity may erode dental enamel. But research has shown that honey contains a component that protects calcium phosphate from dissolving in acid (Edgar and Jenkins 1974; Jenkins, Forster, and Speirs 1959). A study measuring enamel microhardness and examining enamel by scanning electron microscopy found no evidence of decalcification after exposure of enamel to 100%, 50% and 25% honey for 3 hours (Grobler, du Toit, and Basson 1994). The protective agent in honey appears to be an organic phosphate ester of some sort (Edgar and Jenkins 1974). Prolonged incubation of honey in the presence of saliva was found to cause the degradation of this ester, but this was only partially so in a period of four hours (Edgar and Jenkins 1974), whereas honey candy would be in saliva for a period of the order of one minute before the dissolved honey is swallowed and fresh honey dissolves from the candy. However, in a study where volunteers were asked to hold a teaspoonful of honey in the mouth for 5 minutes, measurement of enamel microhardness revealed some decalcification of enamel had occurred, but not in xerostomic individuals (Sela et al. 1998). But any effect of saliva degrading the enamel-protecting factor in honey would not be a problem if honey was in direct contact with the teeth when being used for "anti-infective" therapy of periodontal disease.


0 users have Like. User Likes