Remineralization of early caries by a nano-hydroxyapatite dentifrice

Department of Comprehensive Dentistry, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA.
The Journal of clinical dentistry 01/2011; 22(5):139-43.
Source: PubMed


The purpose of this randomized, double-blind, crossover, in situ study was to evaluate the efficacy of nano-hydroxyapatite (nHAP) dentifrices on caries remineralization and demineralization inhibition.
Three demineralized enamel blocks (A,B,C) and one healthy block (D), cut from each of 30 molars, were exposed respectively to dentifrices of A) 5% nHAP, B) 10% nHAP, C) 1100 ppm fluoride, and D) 10% nHAP via an intra-oral appliance worn by 30 adults in this four-phase study lasting 28 days per phase. Baseline and post-test mineral loss (delta Z) and lesion depth (LD) were quantified using microradiography.
Pair-wise comparison (baseline versus test) demonstrated significant (p < 0.001) reductions in delta Z and LD in A, B, and C. ANOVA showed no significant differences among the three products in percent mineral gain. No demineralization occurred in the sound enamel specimens exposed intra-orally while using 10% nHAP.
nHAP dentifrice caused remineralization comparable to a fluoride dentifrice, and inhibited caries development, thus suggesting that an nHAP dentifrice can be an effective alternative to fluoride toothpaste.

Download full-text


Available from: Bennett Tochukwu Amaechi
  • [Show abstract] [Hide abstract]
    ABSTRACT: The prevention of tooth decay and the treatment of lesions and cavities are ongoing challenges in dentistry. In recent years, biomimetic approaches have been used to develop nanomaterials for inclusion in a variety of oral health-care products. Examples include liquids and pastes that contain nano-apatites for biofilm management at the tooth surface, and products that contain nanomaterials for the remineralization of early submicrometre-sized enamel lesions. However, the treatment of larger visible cavities with nanomaterials is still at the research stage. Here, we review progress in the development of nanomaterials for different applications in preventive dentistry and research, including clinical trials.
    No preview · Article · Aug 2010 · Nature Nanotechnology
  • [Show abstract] [Hide abstract]
    ABSTRACT: Objective: To determine the ability of a Nanohydroxyapatite toothpaste (Apagard Renamel) to occlude the dentin tubules as surrogate measure of its antihypersensitivity effect. Methods: Dentin blocks were produced with the pulpal and cemental surfaces polished to create flat planoparallel surfaces. Then the smear layer from polishing was removed by either 90 seconds sonication in 1% citric acid (pH 4.0) to create opened-dentin-tubules (OD), or sonication in distilled water to retain natural-dentin-tubules (ND). Each group was further subgrouped into treated (ODt and NDt) and untreated (ODnt and NDnt). Treated samples (12/group) were brushed with the test toothpaste for 2 min in each occasion for a total of 10 treatments, while the non-treated (12/group) received no treatment. Then all samples were subjected to a dye penetration test with 0.1 % methylene blue at a flow speed of 0.216 ml/min for 5 minutes. Penetrated dye was collected in distilled water and the color intensity was quantified using spectrophotometer (595 nm) as a measure of the amount of dye that penetrated through the tubules. The treated and untreated subgroups of each group were compared using t-tests, while the four subgroups (ODt/ODnt/NDt/NDnt) were compared by Duncan multiple comparison test. Results: In both OD and ND, dye penetration was significantly (p<0.01, n=12, α=0.05) greater in untreated subgroups (ODnt/NDnt) when compared with the treated (ODt/NDt). Comparing the subgroups, dye penetration was significantly (P<0.01) higher in ODnt compared to ODt, NDnt or NDt. No significant difference was observed in dye penetration in ODt and NDnt. There was no dye penetration through NDt. Conclusion: The study highlighted that the developed dye penetration method can be used to test the tubule occlusion action of antihypersensitivity toothpastes, and demonstrated that the test toothpaste occluded both natural and widened dentin tubule.
    No preview · Conference Paper · Mar 2012
  • [Show abstract] [Hide abstract]
    ABSTRACT: Objectives: Currently toothpastes designed to reduce or relieve pain arising from Dentine Hypersensitivity (DH) are based on either 1) tubular occluding or 2) nerve desensitization properties. The purpose of the present in vitro study was to evaluate the effectiveness of a novel hydroxyapatite toothpaste in occluding dentinal tubules using a recognised dentine disc model Methods: Caries-free extracted maxillary and mandibular molars were used obtained from the tooth bank at the Royal London Dental Hospital. In vitro occlusion of dentinal tubules was investigated using the dentine disc model [Mordan et al. 1997]. The teeth were sectioned mesio-distally into discs approximately 1 mm thick using an internal edge annular diamond blade (Microslice annular blade, Ultratec, USA) mounted on the Microslice 2 saw (Malvern Instruments Ltd., UK) and halved. The dentine discs were etched with 6% citric acid and rinsed with distilled water, prior to evaluation of both test and control toothpastes’ ability to block dentinal tubules by 1) Scanning Electron Microscopy (SEM) of the dentine surface 2) Measurement of fluid flow through dentine before and after 2 minute brushing of the test toothpaste. Results: Following etching and subsequent brushing for 2 minutes of both test and control toothpastes all samples were prepared for SEM evaluation. Surface topography and characterisation of the test toothpaste samples indicated that hydroxyapatite particles covered the surface as well as partially occluding the dentinal tubules to a greater extent than the control product samples. Particle size analysis demonstrated that over 50% hydroxyapatite particles are capable of entering the dentinal tubules. Measurement of fluid flow through dentine sections for the hydroxyapatite samples (n=5) indicated a mean 41.7% (SD: 9.6) reduction in fluid flow compared to baseline values. Conclusions: The results of the present in vitro study would suggest that a novel biomimetic hydroxyapatite may be an effective desensitising agent in reducing DH.
    No preview · Conference Paper · Sep 2012
Show more