IADR Abstract Archives
In Vitro Dentine Occlusion and Rehardening of Commercial Dentifrices
Objectives: Compare two commercial dentifrices for dentine occlusion and re-hardening ability using Scanning Electron Microscopy (SEM) and Vickers Microindentation.
Methods: Polished dentine specimens, from sectioned human permanent molars, were divided into two commercial toothpaste treatment groups 1) Sensodyne Repair and Protect with NovaMin® and 2) Colgate Sensitive Pro-ReliefTM.
Specimens were subjected to the following treatment regimes (n=6) :-
(i). Immersion in 25% dentifrice slurry (2min.) followed by incubation in artificial saliva (AS) at 37oC, six hours; overnight storage in humid conditions at room temperature; removal of dentine specimens for SEM analysis and Vickers hardness measurement on Day 1.
On days 2-4 dentine incubated in AS only with same overnight protocol. SEM analysis and Vickers hardness measurements on days 2, 3 and 4.
(ii). As in (i) with immersion in dentifrice slurry for 2 mins every day.
(iii). As in (ii) but with an acid challenge in citric acid or phosphoric acid on day 4 for both dentifrice groups.
Results: Dentine occlusion measurements by SEM, using a categorical grading scale, demonstrated Sensodyne treated samples to be more occluded in all cases and statistically superior to Colgate for methods (ii) and (iii) following the acid challenge, resulting in a significantly greater resistance to acid.
Vickers Microindentation revealed Sensodyne treated specimens to have a harder surface in all methods tested and was statistically superior to Colgate in re-hardening dentine specimens in method (ii). Sensodyne treated dentine also proved significantly greater resistance to challenge by Phosphoric acid compared with Colgate treated dentine.
Conclusions: These in vitro studies have shown that under these testing conditions, Sensodyne Repair and Protect with NovaMin® provides significantly greater dentine occlusion, further the occlusive layer formed appears to be harder and significantly better resistant to the acid challenge, compared to Colgate Sensitive Pro-ReliefTM treated specimens.
Methods: Polished dentine specimens, from sectioned human permanent molars, were divided into two commercial toothpaste treatment groups 1) Sensodyne Repair and Protect with NovaMin® and 2) Colgate Sensitive Pro-ReliefTM.
Specimens were subjected to the following treatment regimes (n=6) :-
(i). Immersion in 25% dentifrice slurry (2min.) followed by incubation in artificial saliva (AS) at 37oC, six hours; overnight storage in humid conditions at room temperature; removal of dentine specimens for SEM analysis and Vickers hardness measurement on Day 1.
On days 2-4 dentine incubated in AS only with same overnight protocol. SEM analysis and Vickers hardness measurements on days 2, 3 and 4.
(ii). As in (i) with immersion in dentifrice slurry for 2 mins every day.
(iii). As in (ii) but with an acid challenge in citric acid or phosphoric acid on day 4 for both dentifrice groups.
Results: Dentine occlusion measurements by SEM, using a categorical grading scale, demonstrated Sensodyne treated samples to be more occluded in all cases and statistically superior to Colgate for methods (ii) and (iii) following the acid challenge, resulting in a significantly greater resistance to acid.
Vickers Microindentation revealed Sensodyne treated specimens to have a harder surface in all methods tested and was statistically superior to Colgate in re-hardening dentine specimens in method (ii). Sensodyne treated dentine also proved significantly greater resistance to challenge by Phosphoric acid compared with Colgate treated dentine.
Conclusions: These in vitro studies have shown that under these testing conditions, Sensodyne Repair and Protect with NovaMin® provides significantly greater dentine occlusion, further the occlusive layer formed appears to be harder and significantly better resistant to the acid challenge, compared to Colgate Sensitive Pro-ReliefTM treated specimens.