In vitro assessment of 3 dentifrices containing fluoride in preventing demineralization of overdenture abutments and root surfaces

Abstract

Caries development under overdentures has been a continuing problem and requires the daily use offluoride to prevent demineralization. The purpose of this invitro study was to compare the effectiveness of dentifrices containing tricalcium phosphate or calcium phosphosilicate in combination with fluoride to prevent the demineralization of overdenture abutments and root surfaces. A total of 56 caries-free extracted teeth were prepared as overdenture abutments. The teeth were painted withacid-resistant varnish, leaving one 1×4-mm window on occlusal and root surfaces. The teeth were randomly divided into4 groups: a control group treated with distilled/deionized water only, a group treated with ClinPro 5000, a group treatedwith ReNew, and a group treated with Prevident 5000 gel. Each tooth was subjected to a demineralizing/remineralizing cycling protocol for 12 days with the appropriate treatment products. The teeth were sectioned longitudinallythrough both windows. Photomicrographs were made of 3 representative sections from each tooth. Arepresentative section was defined as one that included both windows and was cut from the part of the tooth that had theflattest surface to reduce the edge effect. The depths of the lesions were measured on representative sections from eachgroup. A 1-way MANOVA and a 1-way ANOVA with the post hoc Tukey-Kramer test were used to evaluate the treatmenteffects on the criterion variables (α=.05). The total lesion depths of the control teeth on the occlusal surface were not statistically significantly deeper than forthe 3dentifrices (P=.7705). However, all 3 dentifrices had narrower cavitation depths than the control (meancavitationband depth, 43.59 [ReNew] versus 37.99 [Prevident 5000 gel] versus 36.70 [ClinPro 5000] versus 246.86[control]) (P<.001). The mean remineralization band depth for ClinPro 5000 was significantly greater than for theother 2 treatment groups (118.03 [ClinPro 5000] versus 107.80 [ReNew] versus 102.28 [Prevident 5000 gel]) (P<.001).On root surfaces, the total lesion depth for the control group was statistically significantly deeper than for the3dentifrices (mean total lesion depth, 150.31 [control] versus 82.05 [ReNew] versus 68.10 [ClinPro 5000] versus 56.97[Prevident 5000 gel]) (P<.001). The data indicated that teeth treated with Prevident 5000 gel had the shallowest totallesion depth and were statistically significantly different from those treated with ReNew and ClinPro 5000. Moreover,teeth treated with ReNew were found to have the largest remineralization band depth, which was statistically significantly different compared with ClinPro 5000 and Prevident 5000 gel (mean remineralization band depth, 49.66 [ReNew] versus 36.14 [ClinPro 5000] versus 23.27 [Prevident 5000 gel]) (P<.001), but no difference was found in cavitation depth of the root lesions between the 3 dentifrices. The addition of tricalcium phosphate or calcium phosphosilicate to fluoride-containing dentifrices (5000ppm)does not significantly improve their ability to prevent demineralization of the cut dentin surface of overdentureabutments. However, on root surfaces, ReNew, which contains calcium phosphosilicate, was found to improveremineralization of the lesions compared with Prevident 5000 gel or ClinPro5000.