The effect of denture cleansing solutions on the retention of pink Locator attachments: an in vitro study

To evaluate the changes in retention of pink Locator attachments after exposure to various denture cleansers.

Six groups (20 pairs each) of pink Locator attachments (3.0 lb. Light Retention replacement patrix attachments) were soaked for the equivalent of 6 months of clinical use in the following solutions: Water (control), Polident Regular, Efferdent, 6.15% sodium hypochlorite (NaOCL, 1:10 dilution), Polident Overnight, and Cool Mint Listerine mouthwash. A universal testing machine set at a crosshead speed of 2 in/min was used to perform one pull. The peak load-to-dislodgement was recorded to reflect changes in the retention of the Locator attachments after soaking. Data were analyzed by one-way ANOVA followed by Tukey's Honestly Significant Difference test. A p< or = 0.05 was considered significant.

Denture cleansing solutions significantly affected the retentive values of pink Locator attachments (F = 344.3, p< or = 0.0001). Cool Mint Listerine mouthwash increased the retentive values of the attachments (51.10 +/- 5.31 N) when compared to the control group (45.25 +/- 3.49 N). There was no significant difference in the retentive values of attachments soaked in Polident Regular or Polident Overnight when compared to the control group. Efferdent caused a small reduction in the retentive values (40.81 +/- 2.56 N) and most importantly, diluted NaOCl caused a large reduction in the retentive values (7.83 +/- 2.50 N) of pink Locator attachments. In addition, Cool Mint Listerine mouthwash caused blue discoloration of the Locator attachments, and NaOCl caused whitening and softening of the pink Locator attachments.

Cool Mint Listerine and Efferdent's small effect on the retentive values of the Locators might be clinically unimportant; however, NaOCl caused a large reduction in the retentive values of the attachments. Because of their effect on retentive values and on the color of the Locator attachments, NaOCl and Cool Mint Listerine are not recommended. These results should be interpreted clinically with caution, realizing that different results may be obtained when fatigue stress during function and multiple pulls (in vivo) are combined with the chemical action of denture cleansers.