Anti-hypersensitivity mechanism of action for a dentifrice containing 0.3% triclosan, 2.0% PVM/MA copolymer, 0.243% NaF and specially-designed silica.

PURPOSE: To evaluate the laboratory dentin occlusion efficacy and effects on dentin permeability of a new multi-benefit dentifrice in order to gain insight into the mechanism of action of a novel technology for dentin hypersensitivity relief based on a specially-designed silica and copolymer system. METHODS: Acid-etched human dentin was evaluated with confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM) after treatment with one of the following: (1) a dentifrice containing 0.3% triclosan, 2.0% PVM/MA copolymer, 0.243% sodium fluoride with specially designed silica (Test Dentifrice 1); (2) a dentifrice containing 0.3% triclosan and the same overall silica loading as Test Dentifrice 1 but without copolymer and the specially-designed silica (Placebo Dentifrice); (3) a commercially-available dentifrice containing 0.454% stannous fluoride in a silica base with sodium hexametaphosphate and zinc lactate (Test Dentifrice 2); and (4) a commercially-available non-sensitive dentifrice containing 0.243% sodium fluoride in a silica base (Negative Control Dentifrice). The composition of dentin treated with either Test Dentifrice 1 or Negative Control Dentifrice was analyzed using energy dispersive x-ray (EDX) and electron spectroscopy for chemical analysis (ESCA). To highlight dentin occluding efficacy of the specially-designed silica, dentin was treated with Test Dentifrice 1 formulated with fluorescently-tagged specially-designed silica and resulting occlusion followed with CLSM. The dentin occluding abilities of Test Dentifrices 1 and 2 were compared with the Negative Control dentifrice using CLSM after a 4-day cycling model consisting of twice daily dentifrice treatment and four acid challenges. Effects of treatment with Test Dentifrices 1 or 2 on dentin permeability and subsequent resistance of occluding deposits to acid dissolution and dislodgement by pulpal pressure were assessed using hydraulic conductance. RESULTS: Dentin specimens treated with Test Dentifrices 1 and 2 were significantly occluded compared to Placebo Dentifrice and Negative Control Dentifrice when visualized with CLSM. The level of occlusion remaining after challenge with cola was highest for dentin treated with Test Dentifrice 1 in CLSM xz views. Test Dentifrice 1 produced dentin surface deposits and tubule plugs containing silicon in addition to calcium and phosphorus as indicated by ESCA and EDX. CLSM visualization of fluorescently-tagged material confirmed occlusion by the specially-designed silica which was localized at the dentin tubule openings. Imaging of dentin by CLSM after the 4-day cycling model revealed a significantly higher amount of occluded tubules for dentin treated with Test Dentifrice 1 compared to the Negative Control Dentifrice or Test Dentifrice 2. Etched dentin treated with the Test Dentifrice 1 was significantly less permeable compared to that treated with the Negative Control Dentifrice, exhibiting over 80% reduction in dentin permeability. The occlusion provided by the Test Dentifrice 1 was maintained and provided significantly better reduction in permeability after extended pulpal pressure and acid challenge compared to dentin treated with Test Dentifrice 2.

Mode of action studies on a new desensitizing dentifrice containing 8.0% arginine, a high cleaning calcium carbonate system and 1450 ppm fluoride.

PURPOSE: To ascertain the mode of action of a new Pro-Argin formula desensitizing dentifrice with a gentle whitening benefit containing 8.0% arginine, a high cleaning calcium carbonate system and sodium monofluorophosphate, utilizing a range of state-of-the-art surface techniques. METHODS: Confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM) were used to assess tubule occlusion. Electron spectroscopy for chemical analysis (ESCA) was used to identify the composition of the occlusive material. CLSM was also used to identify the location of the arginine within the occluded dentin tubule and to demonstrate the resistance of the occlusion to an acid challenge. RESULTS: The CLSM and SEM studies demonstrated that the arginine-calcium carbonate technology in this new Pro-Argin formula sensitivity dentifrice was highly effective in occluding dentin tubules. ESCA showed that the dentin surface deposit contained high levels of calcium, phosphorous, oxygen and carbonate. CLSM also confirmed that the arginine incorporated into the dentin plug, and the dentin plug resisted an acid challenge.

Safety profile of a new liquid whitening gel.

Colgate Simply White Clear Whitening Gel, an at-home tooth-whitening product purchased over the counter, contains 18% carbamide peroxide (equivalent to 6.5% hydrogen peroxide) as the active ingredient in a brush-applied liquid gel. The excipients include ingredients commonly used in dentifrices. The potential for effects on the tooth pulp, oral soft tissue irritation, enamel damage, and tooth sensitivity with this peroxide-containing product have been evaluated. An in vitro study demonstrated that pulpal chamber hydrogen peroxide levels are well below those considered to cause an effect on pulpal tissue. An exaggerated-use (4 applications per day for 3 weeks) clinical study showed that no oral irritation occurred during 3 weeks of use. A study measuring peroxide salivary concentration after use of Colgate Simply White Clear Whitening Gel showed that the concentration of peroxide in the saliva after use of the product was extremely low, further supporting the position that this product has a low potential for causing oral irritation. Additional studies demonstrate that Colgate Simply White Clear Whitening Gel does not harm the enamel surface or produce demineralization after exposure equivalent to 3 weeks of normal use and over 6 weeks of exaggerated use. Colgate Simply White Clear Whitening Gel has not produced oral irritation (hard and soft tissues) or tooth hypersensitivity in a clinical subject population of 141 individuals using varying treatment regimens. These studies prove that Colgate Simply White Clear Whitening Gel is safe for daily use as directed.