The moisturizing effect of aloe vera gel appears to be due to the mix of water and polysaccharide components, creating a jelly-like consistency that holds the water within the mix and minimizes its evaporation, providing a sustained moist environment when applied to drying tissues and humectant properties that promote retention of moisture in tissues (11).

Many studies have demonstrated the healing powers of aloe vera gel. A 1996 study reported that a high molecular weight polypeptide constituent from the gel demonstrated a healing effect on excisional wounds in rats (12). Yagi et al reported that aloe vera gel contains a glycoprotein with cell proliferating-promoting activity, while Davis et al noted that aloe vera gel improved wound healing by increasing blood supply, which increased oxygenation as a result (13,14). Thompson reported that topical application of the aloe vera-derived allantoin gel stimulated fibroblast activity and collagen proliferation (15). Heggers et al in 1993 conducted a study and concluded that topical application of aloe vera gel re-established vascularity of burn tissue for a guinea pig, although no specific constituents were identified. Lee et al reported that the low molecular weight component of freeze-dried aloe vera gel stimulated blood vessel formation in a chick chorioallantoic membrane; in addition, a methanol-soluble fraction of the gel stimulated proliferation of artery endothelial cells in an in vitro assay and induced them to invade a collage substrate (16). The aloe vera gel polysaccharide acemannan was shown to activate macrophages, an effect that improved wound healing in a rat model (17,18). A mannose-6-phosphate component of the gel has been credited with a wound healing effectt (19). Various cell toxicity studies were conducted in which human embryonic kidney cells were utilized to determine the effectiveness of aloe gel on cellular longevity. The cellular death rate was found to be reduced by two third when cultured with aloe gel. Aloe vera promoted growth and healing of healthy human cells, the gel did not have the unwanted effect of stimulating the growth of cancer cells.

The literature has many reports concerning the anti-inflammatory effect of aloe vera gel; Hanley et al reported that an aloe vera extract (described as 5.0% leaf homogenate) decreased inflammation by 48% in a rat adjuvant-induced arthritic inflammatory model (20). More recently, the peptidase bradykinase was isolated from aloe and shown to break down the bradykinin, an inflammatory substance that induces pain (21). The gel was found to possess as effective anti -inflammatory effects as Prednisolone and Indomethacin, without having the long term toxicity of either drug (22).

Streptoccocus pyogenes and Streptococcus faecalis are two microorganisms that have been inhibited by aloe vera gel (23,24). Heggers et al suggested that the antibacterial effect of the aloe vera gel in vivo could enhance the wound healing process by eliminating the bacteria that contributed to inflammation (25). Aloe vera gel reportedly was bactericidal against Pseudomonas aeruginosa while acemannan prevented it from adhering to human lung epithelial cells in a monolayer culture. A processed aloe vera gel preparation reportedly inhibited the growth of Candida albicans (23). In terms of antiviral effects, acemannan reduced herpes simplex infection in two cultured target cell lines (26). In a study Saoo et al noted that fractions of aloe vera gel containing lectins directly inhibited the cytomegalovirus proliferation in cell culture, perhaps by interfering with protein synthesis (27). Sydiskis et al tested a purified sample of aloe emodin on the infectivity of herpes simplex virus Type 1 and Type 2 and found that aloe emodin inactivated all of the viruses, including varicella-zoster virus, influenza virus, and pseudorabies virus (28). Electron micrograph examination of anthroquinone-tested herpes simplex virus demonstrated that the envelopes were partially disrupted. These results showed that anthraquinones extracted from a variety of plants (including aloe vera) are directly virucidal to enveloped viruses (29). In a 2003 study by Barrantes and Guinea, a collagenase from Clostridium histolyticum was dose-dependently inhibited by aloe vera gel and an active aloe vera gel fraction containing phenolics and aloins; aloe vera gel and aloins also were effective inhibitors of stimulated granulocyte matrix metalloproteinases(MMPs). The authors observed some chemical structural similarities between the aloins and the MMP inhibitory tetracyclines and finally suggested that the aloe derivatives could inhibit the MMPs through a mechanism similar to that of inhibitory tetracyclines such as doxycycline.

An important finding by Zimmerman was that these effects of aloe vera were not apparent until there was at least 70% concentration of the gel. To achieve 70 % or more concentration an aloe vera gel must be stabilized with antioxidants in order to minimize the otherwise necessary preservatives which lessens the percentage of aloe vera in the product (30). According to George D aloe must not be treated with excessive heat or filtered during the manufacturing process, as this destroys or reduces the effects of certain essential compounds such as enzymes or polysaccharides (31).

The mouth is a breeding ground for bacteria which can be a major problem if preventative measures are not taken because these bacteria can attack the teeth and gums, and can lead to bad breath, gingivitis, stomatitis and peridontitis. Aloe vera, however, has many anti-bacteria qualities that is why it is said to be very effective in fighting the bacteria and preventing these problems. It is extremely helpful in the treatment of gum diseases. It reduces swelling of the soft tissues and consequently this reduces the bleeding of the gums. It exhibits strong antiseptic action in gum pockets where normal cleaning is difficult. Its antifungal properties helps greatly in the management of denture stomatitis. Cracked and split corners of the mouth are also subject to fungal infection and this can be cured by Aloe. Its antiviral properties help in the treatment of cold sores (Herpes Simplex) and shingles (Herpes Zoster). It is a powerful healing promoter and when inserted into extraction sockets is very beneficial. It can be used in any surgical wound. It has a use in root canal treatment as a sedative dressing, healing promoter and file lubricant. Aloe vera can be used around dental implants to control inflammation from bacteria contamination. An extract from aloe vera has been shown to be benefitial and some dentists recommend 1-3 tablespoon of aloe vera juice to be used as a mouthwash, then swallowed three times daily (32).

Aloe vera as a tooth gel is intended to perform the same function as tooth paste which is to eliminate disease causing bacteria in the mouth. Aloe vera in tooth gel is used to cleanse teeth and gums as effectively as toothpaste does. Because aloe vera tooth gel does not contain the abrasives found in most tooth pastes, it is less harsh on teeth and is a great alternative for people with sensitive teeth or gums.

George D, Bhat SS, Antony B conducted a study to compare the antimicrobial efficacy of aloe vera tooth gel (Forever Bright, Forever Living Products, Scottsdale, AZ), and two popular tooth pastes pepsodent (Unilever, Englewood Cliffs, NJ) and colgate (Colgate-Palmolive, Canton, MA), and concluded that aloe vera tooth gel was as effective as two commercially popular tooth pastes in controlling all the organisms ( S.mutans, candida albicans, lactobacillus acidophilus, enterococcus faecalis, prevotella intermedia and peptostreptococcus anaerobius, S,mitis) used in the study. In addition gel demonstrated superior antibacterial effect against S. mitis despite the absence of additional fluoride (31).

A small amount of gel can be placed in the denture once or twice daily. Taste is not bad and is not harmful if swallowed. It acts as an antifungal agent. This can also be used along with soft liners (33).

Because of the sticky and viscous nature of gel, a prototype acemannan was formulated into a denture adhesive and evaluated for adhesive strength in both wet and dry conditions; the adhesive also was used to evaluate cytotoxicity to human gingival fibroblasts. An optimal formula with a high and relatively stable adhesive bond strength and minimum cytotoxicity was observed (34).