A double-blind randomizedcontrolled trial comparing the desensitizing efficacy of a new dentifrice containing carbonate/ hydroxyapatite nanocrystals and a sodium fluoride/potassium nitrate dentifrice
Orsini G, Procaccini M, Manzoli L, Giuliodori F, Lorenzini A, Putignano A. A doubleblind randomized-controlled trial comparing the desensitizing efficacy of a new dentifrice containing carbonate/hydroxyapatite nanocrystals and a sodium fluoride/potassium nitrate dentifrice. J Clin Periodontol 2010; 37: 510–517. doi: 10.1111/j.1600-051X. 2010.01558.x.
Background and Aim: Several dentifrices have shown to be effective in reducing dentine hypersensitivity (DH), but more effective products are needed. The aim of the study was to evaluate the desensitizing efficacy of a new dentifrice based on zinc– carbonate hydroxyapatite (CHA) nanocrystals.
Methods and Materials: Using a double-blind, randomized design, the new dentifrice was compared with potassium nitrate/fluoride dentifrice (active control).
The participant’s DH was evaluated at baseline and after 4 and 8 weeks using airblast (primary outcome), tactile, cold water and subjective tests (secondary outcomes).
Results: The final sample consisted of 70 subjects with baseline DH; 36 received the new dentifrice and 34 the control one. Both dentifrices were largely effective; the percentage of score reduction from baseline to 8 weeks was greater than 28% for all tests (and greater than 55% for the cold water test) in both groups. As compared with controls, experimental subjects had a significantly greater improvement in the airblast test score (mean percentage of reduction of 46.0% versus 29.4% in controls) and the subjective test score (47.5% versus 28.1%, respectively), with both differences already being significant after 4 weeks. In contrast, there was no significant difference between groups for either the tactile or cold water tests at any time point and with any outcome.
Conclusions: This study documented that the new dentifrice containing zinc–CHA nanocrystals significantly reduced dentinal hypersensitivity after 4 and 8 weeks, supporting its utility in clinical practice.
Key words: carbonate hydroxyapatite nanocrystals; dentifrice; dentine hypersensitivity; potassium nitrate; RCT
Accepted for publication 3 February 2010
Giovanna Orsini1, Maurizio
Procaccini1, Lamberto Manzoli2,
Francesca Giuliodori1, Alessandro
Lorenzini1 and Angelo Putignano1 1Department of Clinical Sciences and
Stomatology, Polytechnique University of
Marche, Ancona, Italy; 2Section of
Epidemiology and Public Health, University ‘‘G. d’Annunzio’’ of Chieti, Chieti, Italy
Conflict of interest and source of funding statement
All authors declare that they have no conflicts of interests.
Coswell S.P.A. provided the materials and a partial grant support for this study, but had no role in the planning, conduction, data analysis and any phase of the study.
Dentine hypersensitivity (DH) is characterized by a short, sharp pain arising from the exposed dentine in response to thermal, evaporative, tactile, osmotic or chemical stimuli, which cannot be
J Clin Periodontol 2010; 37: 510–517 doi: 10.1111/j.1600-051X.2010.01558.x 510 r 2010 John Wiley & Sons A/S ascribed to any other form of dental defect or pathology (Addy 1992, Holland et al. 1997). The condition can arise as a result of enamel loss caused by attrition, abrasion or erosion and can be often associated with exposed root surfaces of canines and premolars (Orchardson & Collins 1987).
DH is a common problem with prevalence varying widely, affecting between 3% and 57% of adults (Addy 1990, Rees & Addy 2004). The most widely accepted theory of the mechanism of DH is the hydrodynamic theory proposed by Brannstro¨m (1963).
According to this theory, stimuli cause a rapid displacement of fluid within exposed, open tubules, which in turn excite nerve terminals at the inner ends of the tubules or in the periphery of the pulp. In support of this theory, clinical evidence shows that individuals with
DH have dentinal tubules that are patent from the pulp to the oral environment and sensitive dentine surfaces have wider and more numerous tubules than non-sensitive surfaces, which are mostly covered by a smear layer (Absi et al. 1987).
A number of treatment regimens have been recommended over the years, and particular attention has been focused on ‘‘home use’’ dentifrices containing various ‘‘active’’ compounds, either blocking the hydrodynamic mechanism or the neural response (Yates et al. 2005).
Variations in DH symptoms occur according to the extent of opened dentinal tubules (Lee et al. 2008). Therefore, an effective method to occlude patent dentinal tubules may prove to be beneficial in treating DH. At one time, strontium salts were the most common desensitizing agents (Pearce et al. 1994), after which potassium salts became the most popular active ingredients of dentifrices licensed for use in DH treatment (Orchardson & Gillam 2000, Poulsen et al. 2006, Bellamy et al. 2009). Most of the products and devices used to contrast DH and enamel and dentine erosion, behave by reducing stimuli conduction and apatite dissolution rather than aiming to promote mineralization through apatite crystallization or the replacement of the lost mineral (Young et al. 2006, Roveri et al. 2009a, b).
Hydroxyapatite (HA), in bone as well, is responsible for the mechanical behaviour of the calcified tissues. Unlike bone, in enamel and dentine, when HA is dissolved or abraded, it cannot spontaneously re-mineralize because enamel contains no cells and dentine apposition occurs only toward the pulp tissues (Roveri et al. 2009a, b). Recently, synthetic carbonate HA (CHA) biomimetic nanocrystals have been shown to produce in vitro re-mineralization of the altered enamel surfaces and to be effective in closing dentinal tubules, thus showing a potential use in desensitizing dentifrices (Rimondini et al. 2007, Lee et al. 2008, Roveri et al. 2008, 2009a, b).