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

Antibiofilm and Protein-Repellent Polymethylmethacrylate Denture Base Acrylic Resin for Treatment of Denture Stomatitis

Candida albicans (C. albicans) biofilm is a common etiological factor in denture stomatitis. The purpose of this study was to investigate the effects of incorporating 2-methacryloyloxyethyl phosphorylcholine (MPC) as a protein repellent into a new high-impact denture acrylic (HIPA) resin on the surface roughness, solution pH, and C. albicans biofilm adhesion to the denture base. The new acrylic denture resin base was formulated by mixing MPC into HIPA resin at mass fractions of 1.5%, 3%, and 4.5%. Surface roughness was measured using a Mitutoyo surface roughness tester. C. albicans biofilm growth and viability were assessed via colony forming unit counts. The pH of the biofilm growth medium was measured using a digital pH meter. Adding MPC to the HIPA resin at percentages of 1.5% and 3% increased the roughness values significantly (p < 0.05), while adding 4.5% MPC resulted in no difference in roughness values to that of the control group (p > 0.05). All experimental groups demonstrated neutral pH values (pH ≅ 7) and were not significantly different from each other (p > 0.05). Incorporating 2-methacryloyloxyethyl phosphorylcholine at 4.5% resulted in a significant (≅1 log) colony-forming unit reduction compared with the control group with 0% MPC (p < 0.05). A fungal-retarding denture acrylic resin was developed through the incorporation of MPC for its protein-repelling properties. This newly developed denture acrylic material has the potential to prevent oral microbial infections, such as denture stomatitis.

Management of Edentulous Patients

Edentulism, defined as the complete loss of all dentition, is a worldwide phenomenon. Edentulism occurs because of biologic disease processes, such as dental caries, periodontal diseases, trauma, and oral cancer. Edentulism is accompanied by several comorbidities that can significantly influence an individual. Although the rate of edentulism is declining, the number of edentulous patients continues to rise because of the increase in population. The management of edentulous patient has been addressed since the early days of dentistry. This article describes complete dentures and their maintenance, and advanced technology in complete dentures, and in implant-retained and implant-supported prosthesis.

Influence of highly concentrated fluoride dentifrices on remineralization characteristics of enamel in vitro

OBJECTIVES

The aim of this in vitro study was to evaluate the role of highly fluoridated dentifrice on remineralization characteristics of lowly and highly pre-demineralized enamel artificial caries lesions.

METHODS

Bovine enamel specimens were prepared (pH 4.95; 21 days) and discriminated in either lowly [L] or highly [H] pre-demineralized artificial caries lesions. Specimens with a mean ΔZ_baseline,L (95% CI) of 5120 (4995; 5245) vol.% × μm and a mean ΔZ_baseline,H of 8187 (8036; 8339) vol.% × μm were selected and randomly allocated to 12 groups (n = 20). Treatments during pH-cycling (28 days; 6 × 60 min demineralization/day) were brushing 2×/day with fluoride-free (0 ppm F^- [L₀/H₀]), 1100 ppm F^- [L₁₁₀₀/H₁₁₀₀], 2800 ppm F^- [L₂₈₀₀/H₂₈₀₀], 5000 ppm F^- [L₅₀₀₀/H₅₀₀₀], 5000 ppm F^- + glycerin [L_{5000 + glycerin}/H_{5000 + glycerin}], and 5000 ppm F^- + TCP [L_{5000 + TCP}/H_{5000 + TCP}] containing dentifrices. Dentifrice slurries were prepared with deionized water (1:3wt/wt). After cycling specimens presenting lesion surface loss were discarded and for the remaining 202 specimens, transversal microradiographic (TMR) analyses (ΔZ_pH-cycle/LD_pH-cycle) were performed again. Changes in mineral loss (ΔΔZ = ΔZ_baseline - ΔZ_pH-cycle) and lesion depth (ΔLD = LD_baseline - LD_pH-cycle) were calculated.

RESULTS

Significant differences for ΔΔZ could be found between L₀, L₁₁₀₀, and L₅₀₀₀ as well as H₀, H₁₁₀₀, and H₂₈₀₀/H₅₀₀₀ (p ≤ 0.01; ANCOVA). Except for 0 ppm F^-, higher ΔΔZ could be found in highly compared with lowly demineralized specimens (p ≤ 0.004; ANCOVA). After pH-cycling, a second lesion front could only be observed in H₅₀₀₀ and H_{5000 + TCP}. The correlation between ΔΔZ and F^- was moderate for lowly and highly demineralized lesions (r_L = 0.591; p_L < 0.001; r_H = 0.746; p_H < 0.001), indicating a fluoride dose response for both.

CONCLUSION

For both baseline substrate conditions, a dose response for fluoride could be revealed.

CLINICAL SIGNIFICANCE

Remineralization characteristics of enamel directly depended on baseline mineral loss.