Effect of desensitising toothpastes on dentinal tubule occlusion: a dentine permeability measurement and SEM in vitro study.
OBJECTIVE
The purpose of this study was to evaluate the in vitro effectiveness of a new bioglass-containing and two commercial desensitising toothpastes on dentinal tubule occlusion after citric acid challenge or artificial saliva (AS) immersion.


METHODS
One hundred dentin discs from human third molars were used. Specimens were randomly divided into five groups (n=20), Group 1: EDTA-treated dentin; Group 2: brushing with distilled water; Group 3: brushing with Novamin; Group 4: brushing with Sensodyne Freshmint; Group 5: brushing with Colgate Sensitive. In each group, samples were then equally split into two subgroups (n=10) to test two post-treatments: 6% citric acid challenge or 24h immersion in artificial saliva. Dentine permeability of each specimen was measured before and after each treatment using a hydrostatic device working at 20cm H(2)O pressure. Data were analysed by two-way repeated measures ANOVA to determine if there were any significant differences within or between groups. Dentine morphology and surface deposits were observed by SEM.


RESULTS
All three desensitising toothpastes significantly reduced dentine permeability and created precipitates on the treated dentine surfaces. Moreover, the reductions in dentine permeability showed partial recovery after a citric acid and artificial saliva immersion. Sensodyne showed significant resistant to acid attack and Novamin exhibited the lowest permeability after artificial saliva immersion for 24h.


CONCLUSIONS
The application of the three toothpastes resulted in effective dentinal tubule occlusion. However, the new bioglass-containing toothpaste (Novamin) represented excellent occlusion effects after brushing treatment and AS immersion, while Sensodyne demonstrated more reduction in permeability when citric acid challenged.
Wang
Zhejun
Z
Key Laboratory for Oral Biomedical Engineering, Ministry of Education, School and Hospital of Stomatology, Wuhan University, 237 Luoyu Road, Wuhan 430079, PR China.
Sa
Yue
Y
Sauro
Salvatore
S
Chen
Hao
H
Xing
Wenzhong
W
Ma
Xiao
X
Jiang
Tao
T
Wang
Yining
Y
D000704:Analysis of Variance; D045424:Complex Mixtures; D003804:Dentin / Q000187:drug effects / Q000648:ultrastructure; D057133:Dentin Desensitizing Agents / Q000494:pharmacology*; D003806:Dentin Permeability / Q000187:drug effects*; D004338:Drug Combinations; D005459:Fluorides; D005898:Glass; D006801:Humans; D008855:Microscopy, Electron, Scanning; D009566:Nitrates; D010710:Phosphates; D017680:Potassium Compounds; D018709:Statistics, Nonparametric; D014100:Toothpastes / Q000494:pharmacology*
D045424:Complex Mixtures; D057133:Dentin Desensitizing Agents; D004338:Drug Combinations; D009566:Nitrates; C510984:NovaMin; D010710:Phosphates; D017680:Potassium Compounds; C097427:Sensodyne; D014100:Toothpastes; C444700:colgate sensitive; D005459:Fluorides