CALCIUM PHOSPHATE NANOPARTICLES REDUCE DENTIN HYPERSENSITIVITY : A RANDOMIZED , PLACEBO-CONTROLLED STUDY
Original Articles by many confounding factors such as the socioeconomic-religious environment . This difference shows the importance of performing several studies with different populations from as many different environments as possible , particularly when testing the clinical behavior of therapies influencing a patient ’ s pain perception . From this point of view , the setting itself where the investigations were carried out may be an additional confounding factor , since in the present study it was constituted by some private dental clinics while Mehta et al . evaluated patients seeking cure at a hospital Dental College . 14 , 15 Apart from the aforementioned factors , this distinction may have had an influence on the general health expectations patients had . An additional difference between our study and that of Metha et al . 15 is that the latter evaluated Teethmate AP paste , produced by the same manufacturer as the desensitizer tested here . The main difference between the two products is that the paste is a waterfree calcium phosphate compound , while the test DD used in this study is a mixture of calcium phosphate powder with water , containing an accelerator that leads upon mixture and application to the reaction producing and precipitating hydroxyapatite nanocrystals . 18 Comparing all findings , the pain reduction obtained by the paste desensitizer was slower and more moderate than that of the DD tested in this study . According to Holland et al ., 11 assessments were made between contralateral teeth , and one side of the mouth served as a control for the other side ( split-mouth model ). A randomization list was used to assign each side to either test or control treatments . The comparisons were made between an active treatment ( test DD ) and a placebo that had aspect and composition identical to the active treatment , save for the active principles . In a previous study 15 comparisons were made between a similar DD and distilled water ( placebo ) for up to 6 months . In a pilot study we performed on 3 patients ( data not shown ), we saw that differences between placebo and test compounds were noticeable as of 1 week after treatment . It must be noted that all enrolled patients of this study reported discomfort levels in response to air blast ≥6 on VAS scale , and the tested treatment aimed to reduce pain perception . Contrary to the study design adopted by Mehta et al ., 15 in the present study it was therefore decided not to prosecute observations on the placebo group for
References longer than the minimum amount of time necessary to assess a difference between placebo and test ( 1 week ), since this would provide patients with further , unnecessary discomfort . Another difference in the study design regarded the assessment of hypersensitivity , since in the present study , contrary to Mehta et al ., 14 , 15 it was decided not to use the scrape test . The guidelines on conducting trials on dentin hypersensitivity suggested , as an example of response-based method , the use of cold stimuli , such as timed air blast , or tactile stimuli . 11 In the study conducted by Mehta et al , as well as in many other studies , response was evaluated using both air blast and the tactile running of a dental explorer across the cervical area of the assigned teeth , in horizontal and vertical direction at a “ relatively mild force ”. If one considers the microscopical and submicroscopical structure of enamel and dentine , however , it is clear that the tactile test is invasive and may produce damage to tooth structures at that level . Furthermore , tactile tests , if applied immediately after desensitization , may locally disturb the precipitated layer of nanocrystallites , hampering their further deposition and organization to occlude dentin tubule orifices . For this reason , any contact test was avoided in the present study , and further studies may be performed to assess the influence of tactile stimuli on the behavior of biomimetic hydroxyapatite-forming dentin desensitizers .
5 . Conclusion The results obtained in this study showed that the tested DD effectively reduced patient discomfort caused by dentin hypersensitivity during a 6-month follow-up , up to 69 % after 3 months , after one single application . Biomimetic , hydroxyapatite-forming desensitizers may be an effective solution to dentin hypersensitivity .
Disclosure No conflict of interest exists for any of the Authors of the paper . This research did not receive any specific grant from funding agencies in the public , commercial , or notfor-profit sectors .
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